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HomeMy WebLinkAboutPackets - Stormwater Utillity Commission (212)       AGENDA STORMWATER UTILITY COMMISSION REGULAR SESSION MAY 21, 2026 HOPI CONFERENCE ROOM 11000 N. LA CAÑADA DRIVE        REGULAR SESSION AT OR AFTER 4:00 PM   CALL TO ORDER   ROLL CALL   CALL TO AUDIENCE - at this time, any member of the public is allowed to address the Commission on any issue not listed on today’s agenda. Pursuant to the Arizona open meeting law, individual Commission members may ask Town staff to review the matter, ask that the matter be placed on a future agenda, or respond to criticism made by speakers. However, the Commission may not discuss or take legal action on matters raised during "Call to Audience." In order to speak during "Call to Audience", please specify what you wish to discuss when completing the blue speaker card.   COUNCIL LIAISON COMMENTS (INFORMATIONAL ONLY)   DIRECTORS REPORT (INFORMATIONAL ONLY)   REGULAR SESSION AGENDA   1.REVIEW AND APPROVAL OF THE MARCH 19, 2026 AND THE APRIL 16, 2026 MEETING MINUTES   2.DISCUSSION OF MEETING AND EVENTS   3.DISCUSSION OF APRIL 16, 2026 STORMWATER UTILITY COMMISSION FIELD TRIP   4.DISCUSSION OF 2025/2026 TOWN OF ORO VALLEY MS4 COMPLIANCE SCHEDULE, THIRD QUARTER REPORT   5.PRESENTATION AND DISCUSSION OF ORO VALLEY MONSOON PREPAREDNESS   6.PRESENTATION, DISCUSSION, AND POSSIBLE ACTION REGARDING RECOMMENDATION TO FORWARD AMENDMENTS TO TOWN CODE CHAPTER 17 TO THE MAYOR AND COUNCIL FOR CONSIDERATION AND ADOPTION   ADJOURNMENT   POSTED: 5/15/26 at 5:00 pm by ck When possible, a packet of agenda materials as listed above is available for public inspection at least 24 hours prior to the Commission meeting in the Town Clerk's Office between the hours of 8:00 a.m. – 5:00 p.m. The Town of Oro Valley complies with the Americans with Disabilities Act (ADA). If any person with a disability needs any type of accommodation, please notify the Town Clerk’s Office at least five days prior to the Commission meeting at 229-4700. INSTRUCTIONS TO SPEAKERS Members of the public have the right to speak during any posted public hearing. However, those items not listed as a public hearing are for consideration and action by the Commission during the course of their business meeting. Members of the public may be allowed to speak on these topics at the discretion of the Chair. If you wish to address the Commission on any item(s) on this agenda, please complete a blue speaker card located on the Agenda table at the back of the room and give it to the Recording Secretary. Please indicate on the speaker card which item number and topic you wish to speak on, or if you wish to speak during “Call to Audience,” please specify what you wish to discuss when completing the blue speaker card. Please step forward to the podium when the Chair announces the item(s) on the agenda which you are interested in addressing. 1. For the record, please state your name and whether or not you are a Town resident. 2. Speak only on the issue currently being discussed by the Commission. Please organize your speech, you will only be allowed to address the Commission once regarding the topic being discussed. 3. Please limit your comments to 3 minutes. 4. During “Call to Audience”, you may address the Commission on any issue you wish. 5. Any member of the public speaking must speak in a courteous and respectful manner to those present. Thank you for your cooperation. “Notice of Possible Quorum of the Oro Valley Town Council, Boards, Commissions and Committees: In accordance with Chapter 3, Title 38, Arizona Revised Statutes and Section 2-4-4 of the Oro Valley Town Code, a majority of the Town Council, Board of Adjustment, Historic Preservation Commission, Parks and Recreation Advisory Board, Stormwater Utility Commission, and Water Utility Commission may attend the above referenced meeting as a member of the audience only.”    Stormwater Utility Commission 1. Meeting Date:05/21/2026   Requested by: Dennis Roberts, Public Works Submitted By:Yarina Hynd, Public Works SUBJECT: REVIEW AND APPROVAL OF THE MARCH 19, 2026 AND THE APRIL 16, 2026 MEETING MINUTES RECOMMENDATION: Staff recommends approval. EXECUTIVE SUMMARY: N/A BACKGROUND OR DETAILED INFORMATION: N/A FISCAL IMPACT: N/A SUGGESTED MOTION: I MOVE to approve (approve with changes), the March 19, 2026 Regular Session meeting minutes as presented.  I MOVE to approve (approve with changes), the April 16, 2026 Study Session meeting minutes as presented.  Attachments 03-19-26 Draft Minutes  04-16-26 Draft Minutes  D R A F T MINUTES STORMWATER UTILITY COMMISSION REGULAR SESSION MARCH 19, 2026 HOPI CONFERENCE ROOM 11000 N. LA CAÑADA DRIVE         REGULAR SESSION AT OR AFTER 4:00 PM   CALL TO ORDER Chair Mattson called the meeting to order at 4:02 P.M.   ROLL CALL Present: Robert Aguayo, Vice Chair Tom Marek, Commissioner John McCauley, Commissioner Gary Mattson, Chair Absent: David Atler, Commissioner Staff Present: Dennis Roberts, Stormwater Division Manager Mike Ortiz, Senior Engineering Associate Attendees: Harry Greene, Council Liaison  Commissioner David Atler was excused.   CALL TO AUDIENCE There were no speaker requests.   COUNCIL LIAISON COMMENTS (INFORMATIONAL ONLY) There were no comments at this time.   DIRECTORS REPORT (INFORMATIONAL ONLY) Mr. Roberts commented on the following topics: - Project Delivery and Capital Improvements - System Maintenance and Field Operations - Regional Coordination and Compliance - Community Engagement and Commission Support - Financial Stewardship   REGULAR SESSION AGENDA 3/19/26 Minutes, Stormwater Utility Commission Regular Session 1   1.REVIEW AND APPROVAL OF THE FEBRUARY 19, 2026 MEETING MINUTES    Motion by Commissioner John McCauley, seconded by Vice Chair Robert Aguayo to approve the February 19, 2026 meeting minutes.  Vote: 4 - 0 Carried   2.DISCUSSION OF MEETINGS AND EVENTS    Mr. Roberts discussed recent and upcoming meetings and events. Commissioner McCauley stated that he had seen on recent news reports that Pima County had placed trash traps in the Santa Cruz River to keep debris out of the waterway. He asked if the staff was familiar with the action and has Oro Valley considered the use of trash traps to mitigate debris in the washes. Mr. Roberts advised that he was not familiar with the project and would look into such traps being in use in Pima County and report back to the commission.   3.PRESENTATION AND DISCUSSION OF STORMWATER UTILITY PROJECTS COMPLETED TO DATE    Mr. Roberts provided a presentation that included the following: - Sierra Wash at Via Mandarina - Canada del Oro Tributary Oro Valley Drive 425 Northwest of W Oro Valley Dr. - N Ranch Wash at W Limewood Dr. - South Facing Slope at OV Marketplace on E Tangerine Rd. - Sierra Wash at W Naranja Dr. - Catalina Ridge Channel Access at N Avenida Vallejo - Unknown Tributary Northeast of El Conquistador Tennis Courts - Lambert Lane Improvements During the presentation discussion ensued among the commission and staff.   4.PRESENTATION AND DISCUSSION OF STORMWATER UTILITY CURRENT AND UPCOMING PROJECTS    Mr. Roberts commented on the following Stormwater Utility current and upcoming projects: - Rooney Wash Tributary at E Pusch View Ln. - Nanini Wash at N Paseo Del Norte - Unknown Wash along southbound N Avenida Vallejo - Sierra Wash at W Glover Rd. - Storm Drain 89 at E Rancho Vistoso Blvd - Sierra Wash at N La Cholla Blvd (Weir) - Sierra Wash at N La Cholla Blvd (Channel) - Gravel Pit Wash at N Pomegranate Dr. - Highlands Wash W Appalachian St. to W Matterhorn St. - Mutterers Wash E El Conquistador Wy. to W Greenock Dr. - Carmack Wash at N Shadow Mountain Dr. 300 Feet North of W Spring Valley Dr. - Unknown Wash along southbound N La Canada Dr. (La Canada Noise Wall) Discussion ensued among the commission and staff.   5.DISCUSSION OF THE UPCOMING COMMISSION FIELD TRIP – THURSDAY, APRIL 16, 2026    Mr. Roberts identified the following draft list of proposed field trip stops and requested feedback from the 3/19/26 Minutes, Stormwater Utility Commission Regular Session 2  Mr. Roberts identified the following draft list of proposed field trip stops and requested feedback from the Commission: - Nanini Wash at N Paseo Del Norte - Access Ramp at the Catalina Ridge Channel - Sierra Wash at Naranja - Sierra Wash at Via Mandarina - Sierra Wash at Glover - Storm Drain 89 at E Rancho Vistoso Blvd - Gravel Pit at Pomegranante Dr. - Carmack Wash at N Shadow Mountain Drive near W Spring Valley Dr. Discussion ensued among the commission and staff. Highlands Wash was suggested as a location of interest to be visited on the field trip. Another suggestion was to tour a completed project that had serious problems and that the staff considered to be well done. Mr. Roberts would take the suggestions into consideration.   ADJOURNMENT    Motion by Vice Chair Robert Aguayo, seconded by Commissioner John McCauley to adjourn the meeting.  Vote: 4 - 0 Carried    Chair Mattson adjourned the meeting at 5:01 p.m.     I hereby certify that the foregoing minutes are a true and correct copy of the minutes of the regular session of the Town of Oro Valley Stormwater Utility Commission of Oro Valley, Arizona held on the 19 day of March, 2026. I further certify that the meeting was duly called and held and that a quorum was present. ___________________________ Yarina Hynd Senior Office Specialist 3/19/26 Minutes, Stormwater Utility Commission Regular Session 3 D R A F T MINUTES STORMWATER UTILITY COMMISSION STUDY SESSION APRIL16, 2026 FIELD LOCATIONS         STUDY SESSION AT OR AFTER 7:30 AM   CALL TO ORDER The study session was called to order at 7:43 a.m.   ROLL CALL Present: Robert Aguayo, Vice Chair David Atler, Commissioner John McCauley, Commissioner Gary Mattson, Chair Absent: Tom Marek, Commissioner Staff Present: Dennis Roberts, Stormwater Division Manager Mike Ortiz, Senior Engineering Associate Scott Bennett, Stormwater Utility Analyst Jane Hutchins, Stormwater Utility Inspector Kevin King, Stormwater Utility Intern Attendees: Harry Greene, Council Liaison  Commissioner Marek was excused.   STUDY SESSION AGENDA   1.DISCUSSION DURING TOUR OF STORMWATER RELATED SITES THROUGHOUT THE TOWN The following locations were toured: - Unknown Wash Along Southbound N La Cañada Dr (La Cañada Noise Wall) - Lambert Lane Improvements at La Cholla and Sierra Wash - Sierra Wash at Glover - Sierra Wash at Via Mandarina - Sierra Wash at Naranja Dr - Catalina Ridge Channel Ramp and New Ramp Location 4/16/26 Minutes, Stormwater Utility Commission Study Session Meeting 1 - Highland Mobile Home Park - Gravel Pit Wash at N Pomegranate Dr - Mutterers Wash at Greenock Dr - Shadow Mountain Dr, 300' North of W Spring Valley Dr - Nanini Wash at N Paseo Del Norte    Mr. Roberts presented project information on the field trip locations listed below: - Unknown Wash Along Southbound N La Cañada Dr. - Lambert Lane Improvements at La Cholla and Sierra Wash - Sierra Wash at Glover - Sierra Wash at Via Mandarina - Sierra Wash at Naranja Dr - Catalina Ridge Channel Ramp and New Ramp Location - Highland Mobile Home Park - Gravel Pit Wash at N Pomegranate Dr - Mutterers Wash at Greenock Dr - Shadow Mountain Dr, 300' North of W Spring Valley Dr - Nanini Wash at N Paseo Del Norte Discussion ensued between the commissioners and staff at each project location. Lunch followed the last field trip location.   ADJOURNMENT Chair Mattson adjourned the meeting at 12:47 p.m.         I hereby certify that the foregoing minutes are a true and correct copy of the minutes of the regular session of the Town of Oro Valley Stormwater Utility Commission of Oro Valley, Arizona held on the 16th day of April, 2026. I further certify that the meeting was duly called and held and that a quorum was present. ___________________________ Yarina Hynd Senior Office Specialist 4/16/26 Minutes, Stormwater Utility Commission Study Session Meeting 2    Stormwater Utility Commission 2. Meeting Date:05/21/2026   Requested by: Dennis Roberts, Public Works Submitted By:Dennis Roberts, Public Works SUBJECT: DISCUSSION OF MEETING AND EVENTS RECOMMENDATION: This item is presented for information and discussion only. No action is requested. EXECUTIVE SUMMARY: The following is a list of immediate past, and upcoming, stormwater-related meetings and events:  April 14, 2026 – PCRFCD–TOV SWU Partnering Opportunities April 15, 2026 – Kickoff Meeting: HMGP DR-4524-06-04 Sierra Wash Drainage Improvement at Glover Road April 16, 2026 – Oro Valley Stormwater Utility Commission 2026 Field Trip April 24, 2026 – HMGP FM-5493-7-7R Pomegranate Drive Drainage Improvement Project – BCA Coordination Meeting with DEMA/FEMA April 27, 2026 – Pre-Construction Meeting: Pusch View Lane CMP Replacement Project April 28, 2026 – Oro Valley Stormwater IDDE, Municipal Good Housekeeping, and CGP Training May 5, 2026 – ADEQ Surface Water Stakeholder Presentation May 7, 2026 – PAG Environmental Planning Advisory Committee (EPAC) Meeting May 15, 2026 – Tucson Area Flood Insurance Meeting May 20, 2026 – Regional Flood Control Advisory Committee Meeting May 21, 2026 – Oro Valley Stormwater Utility Commission Meeting May 27, 2026 – HMGP FM-5385-002-002R Sierra Wash Drainage Improvement at Via Mandarina – DEMA Annual Grant Recipient Site Inspection June 17, 2026 – Regional Flood Control Advisory Committee Meeting TBD – PAG Environmental Planning Advisory Committee (EPAC) Meeting BACKGROUND OR DETAILED INFORMATION: Since the Commission’s last regular meeting, staff have continued participating in project-specific coordination, regional committee discussions, stakeholder outreach, and regulatory engagement activities. These meetings support collaboration with partner agencies, advance active capital and grant-funded stormwater projects, and ensure alignment with regional watershed management priorities. Staff will provide brief verbal updates on key discussions and outcomes during the meeting. FISCAL IMPACT: There is no fiscal impact associated with this informational item. Participation in these meetings is part of the Stormwater Utility Division’s routine operations. SUGGESTED MOTION: No motion required. This item is for information and discussion only.    Stormwater Utility Commission 3. Meeting Date:05/21/2026   Submitted By:Dennis Roberts, Public Works SUBJECT: DISCUSSION OF APRIL 16, 2026 STORMWATER UTILITY COMMISSION FIELD TRIP RECOMMENDATION: Report is for disussion purposes only. EXECUTIVE SUMMARY: On April 16, 2026, the Stormwater Utility Commission conducted its annual field tour of stormwater infrastructure sites throughout the Town. Eleven project locations were visited, including active capital improvements, completed post storm restoration projects, and areas identified for future design and maintenance considerations. The purpose of this agenda item is to share field trip photos, provide brief status updates, review the project handout, and offer Commissioners an opportunity to reflect on observations made during the tour.    Field trip locations are documented in the meeting minutes and map of stops. BACKGROUND OR DETAILED INFORMATION: The Commission met at Town Hall at 7:30 a.m. and toured 11 stormwater project locations across the community, as reflected in the April 16, 2026 minutes . Staff provided on site briefings for each project, including current status, recent construction efforts, hydraulic issues, scour and erosion conditions, and expected next steps.    Projects visited included: • Unknown Wash along southbound N La Cañada Dr – active scour and proposed channel realignment and bank protection • Lambert Lane Improvements at La Cholla and Sierra Wash – completed phases with erosion control and structural improvements • Sierra Wash at Glover – downcutting issues and stabilization needs • Sierra Wash at Via Mandarina – completed drop structure and gabion improvements • Sierra Wash at Naranja Dr – completed energy dissipation and erosion control work • Catalina Ridge Channel Access at N Avenida Vallejo – erosion and sedimentation concerns and new maintenance ramp design • Highlands Wash at Appalachian / Matterhorn – undersized channel and proposed capacity increase • Gravel Pit Wash at N Pomegranate Dr – active drainage and erosion mitigation project • Mutterer’s Wash at Greenock Dr – proposed channel stabilization and capacity improvements • Shadow Mountain Dr / Carmack Wash – downstream erosion, utility exposure, and proposed energy dissipation and bank protection • Nanini Wash at Paseo Del Norte – erosion risks, undersized culverts, and proposed guardrail, headwall, and scour protection improvements FISCAL IMPACT: There is no fiscal impact associated with this agenda item. SUGGESTED MOTION: No formal action is required. No formal action is required. Attachments 2026 Field Trip Map  2026 Field Trip Recap  ^_ INA ORACLE LA CHOLLA LA CANADA MAGEE SHANNON LAMBERT 1ST TANGERINE NARANJA OVERTON HARDY CHRISTIE NORTHERN LINDA VISTA MONA LISA CALLE CONCORDIA PUSCH VIEW CORTARO FARMS 1ST HARDY MAGEE 1 9 8 7 6 3 4 5 2 11 10 2026 Stormwater Utility Field Trip Stops Starting PointOro Valley Town Hall Legend Field Trip Stops Stop Number 1: Unknown Wash Along Southbound N. La Canada Dr. 2: Lambert Lane Improvements at La Cholla and Sierra Wash 3: Sierra Wash at Glover 4: Sierra Wash at Via Mandarina 5: Sierra Wash at Naranja Dr. 6: Catalina Ridge Channel Ramp and New Ramp Location 7: Highland Mobile Home Park 8: Gravel Pit Wash at N. Pomegranate Dr. 9: Mutterer's Wash at Greenock Dr. 10: Shadow Mountain Dr. 300 feet North of W Spring Valley Dr 11: Nanini Wash at N Paseo Del Norte ^_Starting Point (Oro Valley Town Hall) Major Streets ¯Miles00.5 1 2026 Field Trip Recap & Commissioner Discussion Dennis E. Roberts, P.E., CFM Stormwater Utility Division Manager Stormwater Utility - Public Works Department Purpose of Today’s Recap • Refresh key locations visited on April 16 • Share field trip photos • Summarize notable conditions observed in the field • Provide brief updates on active projects • Invite Commissioners to share reflections and ask questions. Field Trip Locations Visited 1. Unknown Wash – scour at noise wall 2. Lambert Lane – completed erosion-control improvements 3. Sierra Wash at Glover – downcutting & outlet stabilization 4. Sierra Wash at Via Mandarina – completed drop structure and energy dissipation improvements 5. Sierra Wash at Naranja – completed drop structure and energy dissipation improvements 6. Catalina Ridge Channel Access – sediment removal and new maintenance access 7. Highlands Wash – undersized channel capacity constraints 8. Gravel Pit Wash – active curb/drainage and spillway improvements 9. Mutterer’s Wash – containment and slope stability concerns 10.Carmack Wash Upper Tributary C - Severe erosion and exposed utilities 11.Nanini Wash – roadway undermining & culvert concerns Key Observations from the Field • Scour and downcutting at multiple culvert outlets • Sediment buildup limiting culvert capacity • Need for improved access for maintenance • Erosion related utility exposure at several sites • Successful stabilization work at completed projects. Unnamed Wash at the Noise Wall along La Canada Erosion Mitigation Project Status: Active Last Revised: 5/7/26 Why This Site Matters: Scour is undermining the noise wall and threatens adjacent infrastructure What We Saw in the Field: • 5–6 ft scour below wall footing • Lack of bank protection and vegetation • Channel bend directing flow toward the wall Where We Are Now: Design concept includes realigning the channel and adding bank armor. Next Steps: Finalize alternatives, develop cost estimate, determine permitting needs, and continue developing project prioritization to identify the appropriate fiscal year for construction. La Cholla Wash and Sierra Wash at Lambert Lane Erosion Mitigation Project Status: Complete Phase 1 June 2019, Phase 2 April 2020 Last Revised: 5/7/26 Why This Site Matters: Protects roadway, utilities, and shoulder from overtopping flows. What We Saw in the Field: • Completed erosion-control features • Energy dissipaters and stabilized shoulders • Post-storm conditions look consistent with design intent Where We Are Now: Project is complete; Phase 1 was finished in June 2019 and Phase 2 in April 2020, with all funded phases now fully closed out. Next Steps: Continue periodic monitoring during monsoon events. BEFORE AFTER Why This Site Matters Significant downcutting at the culvert outlet threatens long-term culvert performance and reliable access. Stabilization is needed to protect infrastructure and maintain safe passage. What We Saw in the Field • Downcutting at the outlet • Erosion undermining riprap and curb • Limited access for construction equipment Where We Are Now Funding and permits have been secured, quarterly reporting is underway with the first report submitted, and project funding is programmed for FY26/27. Next Steps • Project bidding expected to open in late July to early August. • Contract award and pre-construction meeting anticipated after monsoon season, around September 15. • Construction scheduling to follow award. Sierra Wash at W Glover Rd. Erosion Mitigation Project In partnership with Status: Active Last Revised: 5/7/26 Why This Site Matters: Reduces downstream scour and protects the culvert. What We Saw in the Field: • Completed concrete drop structure • Gabion mattress and end sill • Stable outlet conditions (after photos) Where We Are Now: Fully constructed (June 2025). Next Steps: Routine monitoring and sediment checks. Status: Completed June 2025 Last Revised: 5/7/26 Sierra Wash at Via Mandarina Erosion Mitigation Project In partnership with BEFORE AFTER Why This Site Matters: Addresses 4–5 ft outlet drop that previously caused severe erosion. What We Saw in the Field: • Completed drop structure • Gabion energy dissipation • Improved flow stability Where We Are Now: Completed May 2023. Next Steps: Monitor performance after high-flow events. Status: Complete May 2023 Last Revised: 5/7/26 Sierra Wash at W Naranja Dr. Erosion Mitigation Project In partnership with BEFORE AFTER Catalina Ridge Channel Access at N Avenida Vallejo Status: Complete May 2023 Last Revised: 5/7/26 Why This Site Matters Sediment accumulation reduces culvert capacity and limits access needed for routine maintenance. What We Saw in the Field • Heavy sediment buildup at the RCBC • Access limitations • Channel-bottom erosion potential, including scour erosion Where We Are Now Design for the maintenance ramp was completed, and the project was fully constructed and closed out in May 2023. Next Steps No further construction actions required; site will transition to routine maintenance monitoring. BEFORE AFTER Catalina Ridge Channel Access at N Naranja Dr. Status: Active Last Revised: 5/7/26 Why This Site Matters Fast, concentrated flows erode the channel bottom, and lack of maintenance access prevents the Town from managing sediment or protecting adjacent property. What We Saw in the Field • Heavy sediment buildup at the RCBC • Access limitations • Channel-bottom erosion potential, including scour erosion Where We Are Now The 70% plans are currently in staff review, and project funding is programmed for FY26/27. Next Steps • Staff to complete the plan set for permitting. • Project bidding expected to open late July to early August. • Contract award and pre-construction meeting anticipated after monsoon season, around September 15. • Construction scheduling to follow award. CATALINA RIDGE CHANNEL SWUC FIELD TRIP SITE VISIT 2026 Why This Site Matters The channel is undersized through the mobile home park, and upstream basin improvements will tie into this reach. What We Saw in the Field • Capacity constraints • Steep downstream drop structures • Elevation limitations Where We Are Now PCRFCD reaffirmed the 10% local match; OPCC ≈ $2.37M. Town will update the OPCC and pursue FEMA/DEMA for inflation-related funding. Public notice is complete. Programmed for FY28/29 pending on funding availability. Next Steps • Update design plans and OPCC; coordinate with DEMA on inflation funding. • Submit revised costs to FEMA/DEMA. • Continue coordination with PCRFCD on potential additional participation. • Integrate funding outcomes into the final design. Lower Highland Wash Flood Control and Channel Improvement Project In partnership with Status: Active Last Revised: 5/7/26 LOWER HIGHLAND WASH SWUC FIELD TRIP SITE VISIT 2026 Gravel Pit Wash at N Pomegranate Dr. Erosion Mitigation Project Why It Matters Improves roadside drainage and reduces erosion along Pomegranate Road. What We Saw in the Field • Need for curb and formed drainage • Flow consolidation at spillway location • Erosion at existing channel Where We Are Now • FEMA EHP review ongoing (≈200 days into 90–270 window). • DEMA accepted budget-increase request; updated BCA in progress. • 70% plans and drainage report ready for review. • OPCC: $433,921.50. • Exploring Pima County for local match; may fit County bond program. • Programmed for FY27/28. Next Steps • Complete updated BCA + documentation for DEMA/FEMA. • Review 70% plans. • Continue funding coordination with DEMA, FEMA, and Pima County. In partnership with Status: Active Last Revised: 5/7/26 Why This Site Matters Undersized slopes and unstable banks create overtopping and flood risks for nearby homes. What We Saw in the Field • Shallow west slope • Areas needing bank elevation • Tree line and utilities limiting design space Where We Are Now PCRFCD has identified this as a high-priority project for the 2027 Flood Control Bond Program. County will lead the CLOMR/LOMR process. Survey is complete; drainage easement documentation and BRIC BCA work underway. Current OPCC: $2.56M; DEMA/FEMA is considering to fund 75%. Town will seek PCRFCD partnership for the 25% local match (≈$640k). Construction anticipated in FY29–30, pending FEMA approval and County match coordination. Next Steps • Finalize drainage easement and supporting survey documents. • Complete BCA and FEMA/DEMA submittals. • Continue coordination with PCRFCD on bond program and match. • Advance toward permitted plan set and FEMA approvals. Mutterer’s Wash Flood Control and Channel Improvement Project In partnership with Status: Active Last Revised: 5/7/26 MUTTERER’S WASH SWUC FIELD TRIP SITE VISIT 2026 Carmack Wash Upper Tributary C Flood Control and Channel Improvement Project Why This Site Matters Severe erosion and exposed utilities create safety and infrastructure risks. What We Saw in the Field • 30-inch downcutting at RCBC • Exposed waterline • Threatened utility pole • Erosion several hundred feet downstream Where We Are Now A Notice of Intent has been submitted to DEMA for BRIC consideration. Updated OPCC: $3.38M. If approved, FEMA would fund 75%; Town would seek PCRFCD support for the 25% match (≈$845k). Project is in early technical development and was not advanced for the current bond cycle. Coordination with PCRFCD will continue as design progresses and downstream needs are defined. Construction is tentatively targeted for FY30–31. Next Steps • Continue BRIC application coordination with DEMA/FEMA. • Advance early design and erosion-protection concepts. • Work with PCRFCD on potential match participation. • Refine project scope as downstream mitigation needs are evaluated.Status: Active Last Revised: 5/7/26 In partnership with Nanini Wash at N Paseo Del Norte Erosion Mitigation Project Why This Site Matters Roadway undermining and deep scour pose immediate safety and infrastructure risks. What We Saw in the Field • 5-foot vertical drop near pavement • Scour 14–18 inches below pipes • Exposed utilities and collapsed slope Where We Are Now Preliminary assessment indicates the need to evaluate whether the existing culverts require resizing, along with potential guardrail and scour protection improvements. Preliminary OPCC is $125K, and the project is programmed for FY26/27. Next Steps • Complete hydraulic analysis. • Verify culvert sizing and design headwall + scour protection. Status: Active Last Revised: 5/7/26 WE APRECIATE YOUR SUPPORT AND COLLABORATION THROUGHOUT THE TOUR. THANK YOU FOR JOINING THE 2026 STORMWATER FIELD TRIP    Stormwater Utility Commission 4. Meeting Date:05/21/2026   Requested by: Dennis Roberts, Public Works Submitted By:Scott Bennett, Public Works SUBJECT: DISCUSSION OF 2025/2026 TOWN OF ORO VALLEY MS4 COMPLIANCE SCHEDULE, THIRD QUARTER REPORT RECOMMENDATION: This report is for discussion purposes only.  EXECUTIVE SUMMARY: The Town of Oro Valley’s Stormwater Management Program and Annual Report to ADEQ identify the Minimum Control Measures (MCMs) used to manage and improve stormwater quality from the MS4. This quarterly update summarizes activities completed during the third quarter of the 2025–2026 reporting period (January 1–March 31), including ongoing and annual Best Management Practices (BMPs). A summary table of MCMs and associated BMPs is included and shows that the Town is current with required compliance activities.    During this reporting period, staff also completed several outreach and training initiatives that support MS4 program implementation, including participation in the STREAM Night event at Wilson K–8 School, annual Illicit Discharge Detection & Elimination (IDDE) training for municipal employees, and distribution of targeted educational materials to local businesses whose activities may affect stormwater quality. These efforts enhance community engagement, improve pollutant prevention practices, and reinforce compliance across municipal and private operations.    The Town will soon transition to a new MS4 permit, scheduled for adoption in September. ADEQ is expected to release a draft for review in the coming months, and staff will provide comments as appropriate. BACKGROUND OR DETAILED INFORMATION: The Town manages stormwater quality in accordance with the Arizona Pollutant Discharge Elimination System (AZPDES) Permit AZG2021-002 that authorizes the discharge of stormwater from the municipal separate storm sewer system (MS4) to receiving waters, including Waters of the United States (WOTUS). The MS4 generally consists of roads, storm drains, and infrastructure carrying runoff into drainage ways or ephemeral stream channels. The Town has a Stormwater Management Program (SWMP) that describes the control measures it uses to manage the quality of discharges from the MS4. These Best Management Practices (BMPs) are: MCM-1. Public Education and Outreach MCM-2. Public Participation and Involvement MCM-3. Illicit Discharge Detection and Elimination MCM-4. Construction Site Runoff Control MCM-5. Post-Construction Runoff Control MCM-6. Pollution Prevention/Good Housekeeping for Municipal Operations The Town’s Stormwater Management Program describes specific practices it uses to achieve compliance with Part 6.4 of the AZPDES Permit related to Minimum Control Measures, including specific implementation dates and frequencies, measurable goals, and responsible departments. Our staff keeps track of these targeted responsibilities and has prepared the attached summary table showing project implementation in terms of completed tasks that are either (A) ongoing or continuous, or (B) to be done a minimum of once each year. This attached summary Table shows that the Stormwater Utility is fully up to date and has met this quarter’s goals for implementing BMP’s that are ongoing and continuous. The next scheduled update will be the MS4 Annual Report summarizing the MS4 activities of reporting year 2025/2026. FISCAL IMPACT: N/A SUGGESTED MOTION: N/A Attachments 3rd Quarter MS4 Compliance Schedule  2025/2026 Town of Oro Valley Quarter 3 MS4 Compliance Schedule July - Sept Oct - Dec Jan - Mar Apr - June MCM-1 Public Education and Outreach BMP 1.1 Create and update informational brochures (A)x x x BMP 1.2 Distribution of informational brochures to the general public (A)x x x BMP 1.3 Distribution of brochures to businesses that potentially affect stormwater quality (B) Scheduled Qtr 4 BMP 1.4 Stormwater content in the Oro Valley Vista Newsletter (B)x BMP 1.5 Outreach events at Town of Oro Valley schools (B) BMP 1.6 Display of outreach materials on Town owned Sun Shuttle buses. (A)x x x BMP 1.7 Stormwater content on the Town of Oro Valley website (A)x x x BMP 1.8 Effective response to public inquiries (A)x x x MCM-2 Public Participation and Involvement BMP 2.1 Public participation through the Stormwater Utility Commission (SWUC) (A)x x x BMP 2.2 Public involvement through notification of monthly SWUC meetings (A)x x x BMP 2.3 Public interaction with SWU Staff (A)x x x BMP 2.4 Solicitation of public comments regarding key components of utility operations (A)x x x BMP 2.5 Encouragement of public participation via volunteer groups sponsored by the TOV (A)x x x BMP 3.1 Implementation of an IDDE program (A)x x x BMP 3.2 Identification and Mapping of the MS4 (A)x x x BMP 3.3 Identification and mapping of the Town's Municipal Outfall Inventory (A)x x x BMP 3.4 Annual Municipal Employee Illicit Discharge Training Program (B)Done: April 2026 BMP 3.5 Training of Town volunteers (A)x x x BMP 3.6 Written IDDE Procedures (A)x x x BMP 4.1 Comprehensive pre-construction site plan review (A)x x x BMP 4.2 Erosion and sediment control for capital improvement projects (A)x x x BMP 4.3 Establishment and review of Town ordinances regarding disposal of hazardous construction site waste, sediment control, and erosion control (A)x x x BMP 4.4 Documentation of procedures (A)x x x BMP 4.5 Personnel Qualifications and Education of Private Contractors/Developers (A)x x x BMP 4.6 Establish Procedures for Receipt and Consideration of Constituent Submittals (A)x x x BMP 5.1 Creation, review and enforcement of post-construction stormwater pollution prevention regulatory mechanisms and standard operating procedures (A)x x x BMP 5.2 Comprehensive GIS Inventory of Active and Finished Construction Projects (A)x x x BMP 5.3 Implement Standard Operating Procedure on Post-Construction Inspections (A)x x x BMP 5.4 Site Plan Reviews (A)x x x BMP 6.1 Inspection of Town of Oro Valley Municipal Operations, Storage, and Maintenance Facilities (A)x x x BMP 6.2 Street Sweeping (A)x x x BMP 6.3 Implementation of SPCC and Operation and Maintenance Plans for Town Maintenance Facilities (A)x x x BMP 6.4 Municipal Employee Training Program (B)Done: April 2026 BMP 6.5 Town of Oro Valley Municipal Vehicle and Heavy Equipment Washing Procedures (A) x x x BMP 6.6 Town of Oro Valley Fleet Maintenance Schedule (A)x x x BMP 6.7 Facility Safety Data Sheet Inventory (A)x x x (A) Ongoing and Continuous (B) Done Only Once Per Fiscal Year x means task completed during indicated quarter S. Bennett 5/1/2026 Quarter MCM-5 Post-Construction Runoff Control MCM-6 Pollution Prevention and Good Housekeeping for Municipal Operations MCM-4 Construction Site Stormwater Run-Off Control MCM-3 Illicit Discharge Detection and Elimination    Stormwater Utility Commission 5. Meeting Date:05/21/2026   Requested by: Dennis Roberts, Public Works Submitted By:Dennis Roberts, Public Works SUBJECT: PRESENTATION AND DISCUSSION OF ORO VALLEY MONSOON PREPAREDNESS RECOMMENDATION: For discussion purposes only. EXECUTIVE SUMMARY: As the summer rainy season approaches, the Town of Oro Valley Stormwater Utility is committed to promoting monsoon awareness and safety. While these seasonal storms offer a refreshing break from the heat, they also bring heavy rainfall, powerful lightning, strong winds, and dust, creating the potential for dangerous flash floods. Flash flooding remains the leading weather-related cause of death in the United States, with nearly half of these fatalities involving vehicles caught in rising waters.    In anticipation of the upcoming monsoon season, the Oro Valley Stormwater Utility has proactively engaged in outreach efforts, collaborating with partnering agencies, residents, and internal staff. Through these coordinated initiatives, we aim to enhance preparedness and safety, ensuring that our community can enjoy the monsoon season while minimizing risks. By staying informed and taking precautionary measures, we can make this summer’s rainy season both enjoyable and secure for everyone.   BACKGROUND OR DETAILED INFORMATION: Explore the following online links which are valuable resources for expert insights and practical tips on staying informed and prepared during the monsoon season.   • Oro Valley Monsoon Preparedness Guide • Oro Valley CodeRED Alerts • Pima County Regional Flood Control District Monsoon Safety Guide • Arizona Emergency Information Network Monsoon Awareness • National Weather Service Monsoon Safety • Oro Valley Sandbag Program • Tucson Electric Power Monsoon Safety   FISCAL IMPACT: N/A SUGGESTED MOTION: N/A Attachments Monsoon preparedness guide  TEP Monsoon Safety  Register CodeRED  Sandbags for Oro Valley Residents  Monsoon Preparedness Presentation  Questions? Call us at 520-229-4850 or email PW@orovalleyaz.gov. DRIVING DURING MONSOON SEASON Thunderstorms, thick dust storms and flash floods are all very common during Southern Arizona’s monsoon season. They also create hazardous conditions for motorists. Given the many washes and hills located within Oro Valley, it is critical to reacquaint ourselves with how best to handle adverse weather conditions while on the road. Heavy Rain •Ensure a safe following distance between cars—four seconds is ideal for stormy weather. Tires lose traction on wet surfaces, which can make it harder to stop suddenly. •Watch for large vehicles traveling through puddles. They can throw blinding sheets of water across your windshield. •If you begin to hydroplane, remove your foot from the gas pedal until you regain traction. Do not brake suddenly. If you are sliding, turn the wheel in the direction of the slide to straighten out. Dust Storms •Avoid driving during dust storms. •Turn on your headlights and slow to a reasonable speed. Never stop on the pavement during a dust storm. •If the storm becomes too severe, pull off the road as far to the right as possible, turn off all lights and set the parking brake. • Do not turn on your hazards or keep your foot on the brake. Other cars may think you are still in motion and try to follow you. Arizona Stupid Motorist Law Many roads which flood during monsoon season have roadblocks or barriers to keep drivers from entering. These signs and barriers must be adhered to, otherwise you could be required to pay for emergency services should you become stuck. Per Arizona State Law A.R.S 28-910, any motorist who drives past a safety roadblock into a flooded wash or channel may be liable for the expense of emergency rescue services (up to $2,000). EMERGENCY PREPAREDNESS The severe storms brought on by monsoon season can lead to a number of different emergencies, from power outages to flash floods. It is vital that all households prepare a contingency plan in case of an emergency. Emergency Kits Each household should put together an emergency kit. These kits should reflect the size of the household and should be maintained and updated regularly. Formulate an Emergency Plan •Identify meeting locations both inside and outside of the neighborhood for your family/household. •Identify non-local emergency locations where you will meet if the inside/outside neighborhood meeting locations are not accessible. This can be an out-of-town friend’s house, shelter, or hotel. •Name an out-of-town contact. This can be someone who lives beyond the immediate area who will serve as the main point of communication for your household. This person is particularly important should your household get split up in an emergency. •Make sure everyone in your household is familiar with alternative routes through town. The route you usually take could become blocked, so it is important to know the area. Evacuation Though rare, there is a possibility that during monsoon weather conditions, evacuations could become necessary. Follow the 5 P’s of Immediate Evacuation in order to be prepared and remain safe. •People and Pets and other livestock •Papers and important documents •Prescriptions like medications, eyeglasses, hearing aids, etc. •Pictures - irreplaceable memories •Personal computer and information on hard drives or disks Oro Valley Monsoon Preparedness Guide Town of Oro Valley Stormwater Utility WHAT IS A MONSOON? Every summer, Southern Arizona experiences a weather phenomenon known as monsoon season. From approximately June 15 to September 30, monsoon season is marked by intense rain, lightning shows and thick dust storms. While the rain provides a welcome relief from the usual arid heat, the high winds and thunderstorms that accompany this weather shift often create treacherous conditions. Dust storms and flash floods are prevalent during this time of year, making it exceedingly important to be prepared. STORMWATER UTILITY The Arizona monsoons provide unique and complex challenges for the Town of Oro Valley, which is why the Stormwater Utility was developed in 2008. This division of the Town’s Public Works Department was established to protect Oro Valley’s working and natural environments before, during and after the occurrence of storm events. Some activities where you can see Stormwater Utility in action include, but are not limited to:street sweeping, storm cleanup, drainage channel vegetation maintenance, storm system inspections, and Adopt-A-Wash Program. The Stormwater Utility is an excellent resource for information about floodplains, stormwater quality, and illicit discharge control. Information provided by TEP at tep.com/monsoon-safety Monsoon Safety 10 Safety Tips While short-term outages are an inconvenience, extended outages from monsoon storm damage can have a larger impact. Just as Tucson Electric Power prepares all year long for storm season by fortifying our electrical system, customers also can prepare to ensure they’re safe and sound if the lights go out. Here are 10 steps to take so you’re ready, no matter what the weather brings: 1. Ready an emergency kit Long before our first severe storm, assemble an emergency kit with essential items your family will need. Your kit should contain a battery-powered radio, flashlights, fresh batteries, a first aid kit, nonperishable food and drinking water– one gallon a day for each person in the household. And don’t forget that your pets also need food and fresh water. Good nonperishable food choices include crackers, dried fruit or trail mix, beef jerky, canned or pouches of chicken or tuna and granola bars, all of which have a longer shelf life. To avoid stumbling around in the dark and possibly hurting yourself, have several light sources, such as a battery-powered flashlight and lantern. Don’t use candles, which can tip over and start a fire. “If you have an emergency kit already, this is the perfect time to update items by checking expiration dates on food and the power levels of batteries,” said Brian Herman, TEP’s Director of Corporate Safety. 2. Watch the weather Follow weather forecasts on the TEP mobile app or tune into local radio and TV stations so that you’ll be aware if severe weather is developing and can prepare. Before storms hit, secure patio furniture and umbrellas and loose objects to prevent their damage and flying debris. Sign up for free weather alerts from NOAA, the National Weather Service and Pima County Emergency Management to stay informed of severe weather warnings. 3. Have backup communications If landline phones are out or your home’s wireless phone needs electricity, your cell phone may be your only communication tool – until the battery runs out of juice. Investing in a solar cell phone charger can help you recharge and make calls in an emergency. Some devices store energy, while others can only provide a charge if the sun is shining on the solar cell. Most devices cost less than $50. To extend your phone’s battery life, turn off background applications, notifications and streaming service or just power it down until you need to use it. In a pinch, use your vehicle’s power outlet with your phone charger to boost your battery or to power other electronics. 4. Turn off your AC TEP recommends that you turn off your air conditioner during a power outage. Why? Well, it’s not doing you any good without electricity anyway … but the real reason has to do with what happens when the power comes back on. When service is restored to a section of our grid that suffered an outage during hot weather, every air conditioner in that area that wasn’t turned off starts up at the same time, trying to get all those warm homes and business back to a comfortable temperature. The problem is that AC units require additional power at the moment they start – much more than they use while operating. The combine d impact of hundreds or thousands of AC units starting up at the exact same moment can trigger reliability problems that cause another outage or even damage your AC unit. Turning off the AC helps protect your unit and our grid. It also provides an opportunity to burn a few extra calories walking back to the thermostat to turn it back on after service is restored. 5. Use surge protectors Lightning strikes during a monsoon storm can sometimes cause power surges that can damage electronics plugged into outlets. Using smart power or surge strips for your television, gaming station and other electronics will protect them from these spikes. You’ll also be protected from the impact that phantom energy can have on your electric bill. 6. Stay away from downed power lines Downed power lines can still be energized and deadly, even if they look harmless. Always stay far away from downed lines, call 911 to report them and keep others away from the area. Never drive over a downed power line or attempt to get out of your car if a power line has fallen on it. Call 911 and wait for help. If you must get out of the vehicle for some reason, here’s how to do that safely: “Open your door and jump out and away from the vehicle being careful not to touch the car and the ground at the same time,” advised Roger Hall, TEP Manager of Transmission & Distribution. “Both feet need to be touching and together when you land or shuffle with your feet close together until you are at least 20 feet away from the vehicle.” 7. Stay cool in extreme heat Outages that occur during extreme heat can pose a real health concern without air conditioning. Drink plenty of water to stay hydrated and wear loose clothing made of a breathable fabric. Consider buying a few battery-powered fans, which are remarkably effective at moving air to make it feel cooler. Using gel-filled cooling neck wraps also can help lower your body temperature. Simply wet the wrap and slip it around your neck for a cooling effect. In extended outages, check TEP’s outage web page for updates, details about community cooling centers that may have been set up and other services available in affected areas. 8. Minimize food loss Keeping the refrigerator and freezer closed will safely keep food cold for about four hours. Adding bags of ice also will extend the cooling time. Once the freezer begins to warm, transfer frozen foods into a cooler with ice. If the temperature of the foo d is higher than 40 degrees for two or more hours, it’s best to throw out the food rather than risk getting sick. Here’s a trick to know whether your food may have spoiled during an extended outage. Place a cup of water in your freezer. After the water freezes, place a coin on top of the ice. If you later find that coin below the ice’s surface, you’ll know the food in your freezer and fridge thawed at some point and the food is likely unsafe to consume. When in doubt, throw it out! Something you can do before an outage is to fill milk jugs with fresh water and place them in your freezer. This will not only help keep your food cold during an outage, but they also can be thawed to provide fresh drinking water. 9. Know your medical options If you rely on an electronic medical device or have refrigerated medications, talk with your medical provider about having a power outage plan. Find out how long your medication can be stored at higher temperatures and get specific guidance for any medications that are critical for life. Possible options might be having a backup generator to power your refrigerator or medical device, using an ice chest for temporary storage or going to the home of a friend who has power. TEP customers with medical devices that require electricity are encouraged to enroll in our Medical Device Alert program. Customers in this program are kept informed about the status of service interruptions and the estimated time of restoration. 10. Prevent electrical hazards during flooding Monsoon storms often are accompanied by heavy rains and flooding. “Never use electric appliances or touch electric wires, switches or fuses when you're wet or when you're standing in water,” Hall suggested. “Keep electric tools and equipment at least 10 feet away from wet surfaces and don’t use electric yard tools if it's raining or the ground is wet. Electricity and water don’t mix well.” Register for CodeRED orovalleyaz.gov/Government/Departments/Town-Managers- Office/Services/Register-for-CodeRED CodeRED is a FREE emergency notification service provided to all residents within Oro Valley that will notify you of emergency information through phone calls, text messages, emails and social media. The system will be used to keep you informed of local events that may immediately impact your safety. As a local resident, you are encouraged to take action and register your cell phone for this service and verify your home location during the enrollment process so you will receive notifications that directly impact your home or business. What is CodeRED and why is it important to me? CodeRED is an emergency notification service that allows emergency officials to notify residents and businesses by telephone, cell phone, text message, email and social media regarding time-sensitive general and emergency notifications. Only authorized officials have access to the CodeRED system. When will CodeRED be used? Any message regarding the safety, property or welfare of the community will be disseminated using the CodeRED system. These may include AMBER alerts, notifications of hazardous traffic or road conditions, boil water advisories or evacuation notices. Registration Now, before such an emergency happens, the Town of Oro Valley wants to ensure that we have contact information for all of our residents and businesses. Online Step 1.Go to website to register your number in the CodeRED community notification system To ensure that the Town of Oro Valley has contact information for all of our residents and businesses you must register cell phone or broadband/VOIP phone number. Visit CodeRED Step 2.Register for managed account or register as guest Creating a managed account will allow you access to modify your existing notification settings and contact information. You may also add an additional address for the CodeRED system to monitor. You may choose to receive text messages as well as general notifications in addition to the Emergency Notifications. Step 3.Check the keep my information private box and agree to Terms and Conditions This will ensure that your data is not shared with third parties and that you are accepting telephone calls from the Town of Oro Valley. Step 4.Click Verify information to complete process. Sandbags for Oro Valley residents Beginning June 15, the Town will provide free sandbags to residents who may need to protect areas of their homes from storm runoff during the monsoon. Sandbags can be picked up beginning mid June 2026 through the duration of the monsoon season, ending September 30, 2026. Due to a limited number of supplies, only Town residents are eligible, and there is a limit of 10 sandbags per vehicle. See TIP to fill bags below. Sandbags are self-service; please bring your own shovel, you will need to bag and load your own sand. If you need assistance loading sandbags into your vehicle please call ahead of time to notify town staff of your need. TIP TO FILL BAGS: Fill sandbags half full using sand or local soil, fold the top of the sandbag down, and then place the bag on its folded top. Oro Valley Residents Pickup Location The 2026 Sandbag Distribution Location will be at Naranja Park, in an empty lot 1,000 feet north of the W Naranja Drive and N Mussette Drive intersection, on the east side of N Mussette Drive. Residents who require assistance may make an appointment with Town Staff to pick up pre-bagged sand at a designated time. For information on how to book your appointment, or for any questions, please contact OV Stormwater Utility Staff 520-229-4850 option 3 or by email at pw@orovalleyaz.gov. An important message from your Oro Valley Stormwater Utility The Oro Valley Stormwater Utility continues to be proactive in managing washes and addressing potential flood issues and is proud to offer this service to Oro Valley residents. The Utility would also like to remind residents that we need your help to make sure our community stays safe and clean during the summer rainy season. If you see any water quality/pollution or flooding issues please contact the OV Stormwater Utility via phone at 520-229-4850 option 3 or via email at pw@orovalleyaz.gov. Lastly, make sure you and your family are prepared for the monsoon! Take a look at Oro Valley's Monsoon Preparedness Guide and sign up for safety alerts. Get started by visiting www.orovalleyaz.gov and typing MONSOON in the search bar. Monsoon Preparedness for Oro Valley Dennis E. Roberts, P.E., CFM Stormwater Utility Division Manager Stormwater Utility -Public Works Department Monsoon Preparedness: Protecting Oro Valley Residents •Understanding the Monsoon Season •Let’s start with the basics—what is monsoon season? •The Hazards Oro Valley Residents Face •Without proper preparation, monsoons can lead to serious consequences. •How Can We Prepare? •The good news is that there are easy steps we can take to stay safe during monsoon season. •Community Resources & Support •Preparedness isn’t just an individual effort—it’s a community effort. Monsoons may be inevitable, but disasters don’t have to be. Town of Oro Valley Definition: A monsoon is a seasonal wind shift that creates alternating wet and dry periods, driven by temperature differences between land and ocean What are Monsoons? The Hazards Oro Valley Residents Face How do Monsoons Impact Oro Valley? Whiletherainprovidesawelcomerelieffromtheusualaridheat,thehighwinds and thunderstormsthataccompanythisweathershiftoftencreatetreacherous conditions. Heavy rainfall leading to flash floods Dust storms reducing visibility Lightning risks during storms. Safe Driving in Monsoon Conditions Heavy Rainfall •Flooded Roads •Maintain a Safe Following Distance. Keep at least four seconds of space between you and the car ahead. Wet roads reduce traction and increase stopping time. •Watch for Water Splash Hazard •Large vehicles can create blinding sheets of water, reduce visibility. Stay cautious near puddles •Hydroplane Recovery Tips •If you start to hydroplane, lift your foot off the gas to regain traction. •Avoid sudden braking – it can make skidding worse. •If sliding, turn the wheel in the direction of the slide to straighten out safely. •Heavy rainfall can turn dry washes into dangerous flood zones. •Flooded roads can sweep away vehicles—"Turn Around, Don't Drown!" Flash Flood Dangers Stormwater Management & Our Role At The Stormwater Utility How Stormwater Management Keeps Oro Valley Safe In preparation for the upcoming monsoon season, the StormwaterUtility undertakes specific operational and maintenance actions to be ready forstormdebris and runoff. Asset InspectionsRoad closureSignage & Coordination with First Responders Wash Maintenance Regional Collaboration & Planning Regional Collaboration for Monsoon Readiness OroValley continues to work with localpartners in preparing for monsoon season The Pima County Multi-Jurisdictional Hazard Mitigation Plan is an essential tool in preparing and mitigating disasters.The plan setsthe stagefor coordination efforts to meet the challenges of the monsoon, as well as other disasters,and allows the regional partnersthe opportunity to applyforfederalassistancefunding. Supporting Regional Monsoon Messaging Effort Spreading the Message The Stormwater Utility supports our regional partners messaging efforts Pima County and the National Weather Service continue to push out messaging with their media partners reaching residents through television, radio, and the internet. Be Ready for Monsoon Season: Resources & Tips for Oro Valley Public Outreach The Stormwater Utility Monsoon Preparedness Guide is available on the Oro Valley webpage Offering information and tips on how to prepare and minimize threats from the seasonal hazards Protect Your Property: Oro Valley’s Free Sandbag Program Starting June 15, the Town will provide free sandbags to residents at Naranja Park, in an empty lot 1,000 feet north of the W Naranja Drive and N Mussette Drive intersection, on the east side of N Mussette Drive. Residents may fill up to 10 bags through September 30 to help protect their property from potential storm damage. Final Takeaways Monsoon Preparedness Starts with You •Monsoon season brings challenges, but preparedness minimizes risks. •Oro Valley’s stormwater systems are in place, but residents play a crucial role. •Simple actions—clearing drains, securing property, and staying informed—make a big difference. •Together, we create a safer, stronger, and more resilient community. •Questions or feedback?    Stormwater Utility Commission 6. Meeting Date:05/21/2026   Requested by: Dennis Roberts, Public Works Submitted By:Dennis Roberts, Public Works SUBJECT: PRESENTATION, DISCUSSION, AND POSSIBLE ACTION REGARDING RECOMMENDATION TO FORWARD AMENDMENTS TO TOWN CODE CHAPTER 17 TO THE MAYOR AND COUNCIL FOR CONSIDERATION AND ADOPTION  RECOMMENDATION: Staff recommends that the Stormwater Utility Commission review the proposed amendments and recommend forwarding the revisions to the Town Council for formal consideration. EXECUTIVE SUMMARY: Town Code Chapter 17, Floodplain and Erosion Hazard Management, was last updated by Ordinance (O)21 06 on November 17, 2021. In January 2023, the Arizona Department of Water Resources (ADWR) conducted a Community Assistance Visit (CAV), a periodic compliance review under the National Flood Insurance Program (NFIP). The CAV identified several recommended updates to better align Chapter 17 with the State of Arizona Floodplain Management Model Ordinance (June 2023) and current state and federal best practices. In response, staff prepared draft amendments that update terminology, clarify administrative procedures, and incorporate all ADWR recommendations. The revisions have been formatted in both redline and clean copies for Commission review. Next Steps: • The Stormwater Utility Commission reviews and provides feedback on the proposed amendments. • If supported, the Commission recommends forwarding the revisions to the Mayor and Council. • Town Legal will prepare the formal ordinance for Town Council consideration. • Following Commission action, staff intends to place the item on the next available Mayor and Council Regular Session agenda. Adoption of these revisions will help ensure ongoing NFIP compliance, protecting the community’s eligibility for federally backed flood insurance and post disaster assistance. BACKGROUND OR DETAILED INFORMATION: Under A.R.S. § 48 3610, municipalities may assume responsibility for floodplain management and adopt regulations consistent with A.R.S. § 48 3609. Oro Valley has done so through multiple Chapter 17 updates, including Ordinances (O)05 35 (2005), (O)17 04 (2017), and (O)21 06 (2021). The 2023 ADWR CAV recommended a series of updates to modernize Chapter 17 and improve consistency with state and federal requirements. These include: • Updating and clarifying definitions • Aligning administrative procedures with current state standards • Eliminating outdated language • Improving technical clarity and internal consistency  Staff incorporated all recommendations, prepared a redline version showing proposed changes, and assembled a clean final draft for adoption consideration. FISCAL IMPACT: No direct fiscal impact is anticipated. Staff time required for drafting, review, and coordination is included in the Stormwater Utility operating budget. SUGGESTED MOTION: I MOVE to recommend forwarding the proposed amendments to Town Code Chapter 17, Floodplain and Erosion Hazard Management, to the Mayor and Council for consideration and possible adoption.  Attachments OV TC Ch 17_Showing Comments from ADWR CAV Reviewer  OV TC Ch 17_Showing Revisions  OV TC Ch 17_Final  Chapter 17 Amendments Presentations  APPENDIX B ANNOTATED ORDINANCE Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 1 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. CHAPTER 17 FLOODPLAIN AND EROSION HAZARD MANAGEMENT Articles: 17-1 Statutory Authorization, Findings of Fact, Purpose and Methods 17-2 Definitions 17-3 General Provisions 17-4 Administration 17-5 Provisions for Flood Hazard Reduction 17-6 Appeal and Variance Procedures 17-7 Ordinance Amendments 17-8 Fees Article 17-1 STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS Sections: 17-1-1 Statutory Authorization 17-1-2 Findings of Fact 17-1-3 Statement of Purpose 17-1-4 Methods of Reducing Flood Losses 17-1-1 Statutory Authorization. The Legislature of the State of Arizona has, in ARS § 48-3610, enabled the Town of Oro Valley to assume the powers and duties for floodplain management and adopt regulations in conformance with ARS § 48-3609 that are designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the Town Council of Oro Valley, Arizona, does ordain as follows. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK1]: In general, comments have priorities ranging from recommended (highest) to suggested (lowest). Additional comments and/or questions are also included for discussion. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 2 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. so as to minimize blight areas caused by flooding; G. To ensure the state mandated required regulatory floodplain information is available to potential buyers; 17-1-2 Findings of Fact. A. The regulatory floodplains of Oro Valley are subject to periodic inundation that may result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare. B. These flood losses are caused by the cumulative effect of obstructions in regulatory floodplains, which increase flood heights and velocities. Also, when these obstructions are inadequately anchored, they may cause damage in other areas. Uses that are inadequately flood-proofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-1-3 Statement of Purpose. It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed: A. To protect human life and health; B. To minimize expenditure of public money for costly flood control projects; C. To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; D. To minimize prolonged business interruptions; E. To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone, and sewer lines, and streets and bridges located in regulatory floodplains; F. To help maintain a stable tax base by providing for the sound use and development of the special flood hazard areas and erosion hazard areas H. To regulate activities within regulatory floodplains for both public and private properties; I. To participate in and maintain eligibility for flood insurance and disaster relief. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK2]: Not consistent, recommend regulatory floodplain Commented [KK3]: Suggested addition Formatted: Highlight Commented [KK4]: In addition to State model, no action needed Commented [KK5R4]: CRS related? Formatted: Highlight Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 3 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-1-4 Methods of Reducing Flood Losses. In order to accomplish its purposes, this chapter includes methods and provisions for: A. Restricting or prohibiting uses which are dangerous to the public health, safety, and welfare as well as public and private property, due to water or development hazards; or which result in increased damages to development or increases in flood heights or velocities; B. Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of start of construction; C. Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help to accommodate natural flood storage potential or the channelization of floodwaters; D. Controlling filling, grading, dredging, and other development that may increase flood damage; and E. Preventing or regulating the construction of flood barriers that unnaturally divert floodwaters, or that may increase flood hazards in other areas. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-2 DEFINITIONS Sections: 17-2-1 Definitions 17-2-1 Definitions. Unless specifically defined below, words or phrases used in this chapter shall be interpreted to give them the meaning they have in common usage, and to give this chapter its most reasonable application. “Accessory structure” means a structure that is on the same parcel of property as a principal structure, the use of which is incidental to the use of the principal structure. For floodplain management purposes, the term includes only accessory structures used for parking and storage. “Appeal” means a request for a review of the Floodplain Administrator’s interpretation of any provision of this chapter or a request for a variance. Appeals are heard and decided by the Floodplain Board. “Area of shallow flooding” means a designated zone AO or AH on a community’s Flood Insurance Rate Map (FIRM) with a one percent (1%) or greater annual chance of flooding to an average depth of one (1) to three Commented [KK6]: Recommend updating definition of "Accessory Structure" based on FEMA TB P-2140 (Aug 2021): For floodplain management purposes, accessory structures are structures that are on the same parcel of property as a principal structure, the use of which is incidental to the use of the principal structure. Accessory structures must be used for parking or storage, be small and represent a minimal investment by owners, and have low damage potential. FEMA considers “small” to mean not larger than a one-story two-car garage. Examples of small accessory structures include, but are not limited to, detached garages, storage and tool sheds, and small boathouses. Structure Size - The footprint of a typical two-car garage is about 600 square feet in area. Storage - Contents stored in wet floodproofed structures will get wet during flooding. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 4 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. (3) feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. “Base flood” means a flood having a one percent (1%) chance of being equaled or exceeded in any given year. “Base flood elevation (BFE)” means the computed elevation to which floodwater is anticipated to rise during the base flood. “Basement” means any area of a structure with a subgrade floor (i.e., below the adjacent ground level) on all sides. Building. See “Structure.” “Community” means any state or area or political subdivision thereof, or any Indian tribe, authorized tribal organization, or authorized Native organization, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction. Critical Facility. Refer to Section 17-5-8(D). “Detention system” means a type of flood control system which delays the downstream progress of floodwaters in a controlled manner, generally through the combined use of a temporary storage area and a metered outlet device, which causes a lengthening of the duration of the flow and thereby reduces downstream flood peaks. “Development” means any manmade change to improved or unimproved real estate, including but not limited to structures, mining, dredging, filling, grading, paving, excavation or drilling operations, and storage of materials and equipment. “Dwelling” means a habitable structure. “Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that is used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a letter of map amendment (LOMA) or letter of map revision based on fill (LOMR-F). “Encroachment” means the advance or infringement of uses, landscape vegetation, fill, excavation, permanent structures, or development into a floodplain that may impede or alter the flow capacity of a floodplain. An equal degree of encroachment is a standard applied to the evaluation of the effects of the encroachment on increases in flood heights. It assumes that an encroachment, if permitted, may confer on all property owners on both sides of the watercourse an equal right to encroach to the same degree within that reach. Since the factors affecting hydraulic efficiency are usually not uniform within a reach, this standard will usually not result in equal measured distances between the regulatory floodway and the regulatory floodplain of the watercourse. “Erosion” means the process of the gradual wearing away of landmasses. This peril is not, per se, covered under the National Flood Insurance Program. Commented [KK10]: Additional definition, no action needed Commented [KK9]: Verify 'landscape vegetation' is anthropological and not natural. Commented [KK8]: Additional definition, no action needed Commented [KK7]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 5 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Erosion hazard area” means lands adjoining a watercourse that is regulated by this chapter which are deemed by the Town Engineer to be subject to flood-related erosion, pursuant to the Town’s adopted drainage criteria manual. “Erosion setback” means the minimum horizontal distance between a structure or permanent feature and the channel bank necessary to protect the structure/feature from flood-related erosion damage. For method to be used for determination of the erosion setback, see the adopted Town of Oro Valley drainage criteria manual. “Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are affixed (including, at a minimum, the installation of utilities, construction of streets, and either final site grading or the pouring of concrete slabs) was completed before December 4, 1979, the effective date of the Flood Insurance Rate Maps adopted by the Town of Oro Valley. “Expansion to an existing manufactured home park or subdivision” means preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads). “Federal Emergency Management Agency (FEMA)” means an agency of the Federal government responsible for programs of disaster response and recovery, disaster preparedness, hazard mitigation, flood insurance, and other programs of technical and financial assistance. “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) the overflow of floodwaters; (2) the unusual and rapid accumulation or runoff of surface waters from any source; and/or (3) the collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in this definition. “Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Emergency Management Agency has delineated both the special flood hazard areas and the risk premium zones applicable to the community. “Flood Insurance Study (FIS)” means the official report provided by Federal Emergency Management Agency that includes flood profiles, the Flood Insurance Rate Map, and the water surface elevation of the base flood. “Flood protection system” means those physical structural works for which funds have been authorized, appropriated, and expended; and which have been constructed specifically to modify flooding in order to reduce the extent of the area within a community subject to designation as a regulatory floodplain as well as the extent and depths of associated flooding. Such a system typically includes dams, reservoirs, levees or Commented [KK13]: Additional definition, no action needed Commented [KK12]: Additional definition, no action needed Commented [KK11]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 6 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. dikes. These specialized flood-modifying works are those constructed in conformance with sound engineering standards. “Floodplain” or “flood-prone area” means any land area susceptible to being inundated by water from any source (see “flood” or “flooding”). “Floodplain Administrator” means the Town Engineer, or their designee, whose duty it is to oversee administration and enforcement of the floodplain management regulations contained in this chapter. “Floodplain Board” means the Town Council of Oro Valley, at such times as they are engaged in the enforcement of this chapter. “Floodplain management” means the operation of an integrated natural resource management program encompassing corrective and preventive measures for reducing flood and erosion damage. Floodplain management includes but is not limited to emergency preparedness planning, flood control works and floodplain management regulations. “Floodplain management regulations” means this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control), and other applications of legal and regulatory authority that control use of, and development in, flood-prone areas. This term describes Federal, State, or local regulations, and any combination thereof, which provide standards for preventing and reducing flood loss and damage. “Floodplain use permit” (also “permit for development in a floodplain”) means an official document that authorizes special activity within regulatory floodplains or erosion hazard areas of Oro Valley. “Flood-proofed” means a watertight structure with walls substantially impermeable to the passage of water, and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy, and by means other than elevation. “Flood-proofing” means any combination of structural and nonstructural additions, changes, or adjustments to nonresidential structures that reduces or eliminates flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents by means other than elevation. “Flood-related erosion” means the collapse or subsidence of land along the shore of a lake or other body of water as a result of undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding. Floodway. See “regulatory floodway.” “Floodway fringe” means that area of the floodplain lying on either side of a regulatory floodway where encroachment may be permitted. Commented [KK17]: Additional definition, no action needed. Suggest including 'dry floodproof' in definition Commented [KK16]: Additional definition, no action needed Commented [KK15]: Recommend including 'open space plans'. Commented [KK14]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 7 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Functionally dependent use” means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long-term storage or related manufacturing facilities. “Governing body” is the local governing unit (i.e., county or municipality) empowered to adopt and implement regulations providing for the public health, safety, and general welfare of its citizenry. “Hardship” means that the physical characteristics of the property in question are so unusual, exceptional, and peculiar to the property that a variance regarding its use may be requested and granted. Mere economic or financial hardship alone is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one’s neighbors likewise cannot, as a rule, be construed to qualify as an exceptional hardship. All of these problems can be resolved through other means without granting a variance, even if the alternative is more expensive, requires the property owner to build elsewhere, or means that the parcel must be put to a different use than originally intended. “Highest adjacent grade” means the highest natural elevation of the ground surface immediately adjacent to a structure prior to construction of the proposed walls of a structure. “Historic structure” means any structure that is: 1. Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; 2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; 3. Individually listed on the State of Arizona inventory of historic places, as approved by the Secretary of the Interior; or 4. Individually listed on the Town of Oro Valley’s inventory of historic places and that has been certified by an approved State of Arizona program, as determined by the Secretary of the Interior. “Levee” means a human-made structure, usually an earthen embankment designed and constructed in accordance with sound engineering practices, for the purpose of containing, controlling, or diverting the flow of water so as to provide protection from temporary flooding. “Lowest floor” means the lowest floor of the lowest enclosed area including the basement (see “basement” definition) or crawl space under a manufactured home if it is not vented. An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered to be the lowest floor of a structure; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this chapter. Commented [KK18]: Suggest reference to 17-6-1 Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 8 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Manufactured home” means a structure, transportable in one (1) or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.” “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale. “Market value” means the determination of the estimated cost to replace the structure in new condition and adjusting that cost figure by the amount of depreciation that has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and functional obsolescence as approved by the Floodplain Administrator but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences. Alternatively, the market value is the valuation made by the Pima County Assessor’s Office. “Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum of 1988 (NAVD ’88), or other datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced. “National Flood Insurance Program (NFIP)” means a program administered by FEMA that makes Federally backed flood insurance available for purchase by individuals that live in NFIP participating communities. New Construction. For the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial Flood Insurance Rate Map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures. “Obstruction” includes, but is not limited to, any dam, wall, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, structure, wire, fence, rock, gravel, refuse, fill, structure, vegetation, or other material in, along, across, or projecting into any watercourse which may alter, impede, retard, or change the direction and/or velocity of the flow of water, or which due to its location influences its propensity to snare or collect debris carried by the flow of water, thereby reducing its likelihood of being carried downstream as well as reducing the channel’s ability to convey flow. “One hundred (100) year flood” means the flood having a one percent (1%) chance of being equaled or exceeded in any given year (see “base flood”). Also referred to as the one percent (1%) annual exceedance probability flood (one percent (1%) AEP flood). Commented [KK21]: Additional definition, no action needed Commented [KK20]: Additional definition, no action needed Commented [KK19]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 9 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Permit for development in a floodplain” (also referred to as a “floodplain use permit”) is an official document issued by the Town of Oro Valley authorizing performance of specific activity in any regulatory floodplain or erosion hazard area after it has been determined to be reasonably safe from flooding and erosion. These permits are required to ensure that proposed development projects meet the requirements of the NFIP and the provisions of this chapter. Examples include grading permits, building permits, and floodplain use permits. “Person” means an individual, firm, partnership, association or corporation, or agent of the aforementioned groups, or the State of Arizona or its agencies or political subdivisions. “Program” means the National Flood Insurance Program authorized by 42 U.S.C. 4001 through 4128, or as authorized by subsequent Federal statutes. “Reach” is a hydraulic engineering term to describe longitudinal segments of a stream or watercourse. A reach will generally include the segment of the flood hazard area where flood heights are primarily controlled by manmade or natural obstructions or constrictions. In an urban area, an example of a reach would be the segment of a stream or watercourse between two (2) consecutive bridge crossings. “Recreational vehicle” means a vehicle that is: 1. Built on a single chassis; 2. Four hundred (400) square feet or less in area, when measured at the largest horizontal projection; 3. Designed to be self-propelled or permanently towable by a light duty truck; and 4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. “Regulatory flood elevation” means an elevation that is one (1) foot above the calculated water surface elevation of the base flood, as established by the State of Arizona for floodplain management purposes. “Regulatory floodplain or flood-prone area” means that portion of the geologic floodplain associated with a watercourse, including its channel, or any other floodplain or flood-prone area that would be inundated by the base flood, including all base floods where the base flood peak discharge is one hundred (100) cubic feet per second or greater, those areas that are subject to sheet flooding except when the maximum potential contributing watershed area is less than twenty (20) acres, those areas identified on subdivision plats or development plans, those areas designated by FEMA, including areas designated as shaded Zone X as well as those areas that the Floodplain Administrator, using the best available data, has determined is subject to a flood hazard during the base flood. “Regulatory floodway” means the channel of a watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated amount. Commented [KK26]: Higher standard, additional definition, no action needed Commented [KK25]: Suggest rewording, varies from ARS. Commented [KK24]: Additional definition, no action needed Commented [KK23]: Additional definition, no action needed Commented [KK22]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 10 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Remedy a violation” means to bring the structure or other development into compliance with State or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of this chapter, otherwise deterring future similar violations, or reducing Federal financial exposure with regard to the structure or other development. “Repetitive loss structure” means a structure, covered by a contract for flood insurance issued pursuant to the National Flood Insurance Act, that has incurred flood-related damage on two (2) occasions during any ten (10) year period ending on the date of the event for which a second claim is made, and for which the cost of repairing the flood damage, on average, equaled or exceeded twenty-five percent (25%) of the market value of the structure at the time of each such flood event. In addition to the current claim, the NFIP must have paid the previous qualifying claim. “Retention system” means a type of flood control system that stops the downstream progress of floodwater by employing methods of total containment which generally involve creation of storage areas that incorporate infiltration devices, such as dry wells, to dispose of stored waters, principally by percolation over some specified period of time, thereby eliminating basin contributions to downstream flood peaks or flood volumes. “Riverine” means relating to, formed by, or resembling a river (including tributaries), stream, brook, etc. Sheet Flow Area. See “area of shallow flooding.” “Special flood hazard area (SFHA)” means an area in the regulatory floodplain subject to a one percent (1%) or greater chance of flooding in any given year. SFHAs are shown on a Flood Insurance Rate Map as Zone A, AO, AE, AH or A0. “Start of construction” includes substantial improvement or other proposed new development, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within the time period when the permit was active. The “actual start” means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation such as the installation of streets and/or walkways, the installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the “actual start of construction” means the first alteration of any wall, ceiling, floor or other structural part of a structure, whether or not that alteration affects the external dimensions of the structure. “Structure” means a walled and roofed building, including gas or liquid storage tanks, principally above ground and affixed to a permanent site. This term also refers to a manufactured home on a permanent foundation. Commented [KK29]: Additional definition, no action needed Commented [KK28]: Additional definition, no action needed Commented [KK27]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 11 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred. “Substantial improvement” means any reconstruction, rehabilitation, addition, or other improvement to a structure, the total cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either: 1. Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local Code Enforcement Official and which are the minimum necessary to assure safe living conditions; or 2. Any alteration of a “historic structure”; provided, that the alteration will not preclude the structure’s continued designation as a “historic structure.” “Variance” means a grant of relief from the requirements of this chapter that is granted by the Floodplain Administrator or the Floodplain Board (for FEMA floodplains) upon a finding that strict enforcement of the provisions would cause undue hardship owing to circumstances unique to the individual property for which the variance is granted, and not caused by the applicant for said variance. “Violation” means the failure of a structure or other development to be fully compliant with the Town of Oro Valley floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required by this chapter is presumed to be in violation until such time as such documentation is provided. “Violation” also means unauthorized construction, grading, encroachment, diversion, or lack of maintenance of private drainage structures. “Water surface elevation” means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929 or the North American Vertical Datum (NAVD) of 1988 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of riverine and sheetflow areas. “Watercourse” means a lake, river, creek, stream, wash, arroyo, channel, or other topographic feature on or over which waters flow at least periodically. “Watercourse” includes specifically designated areas in which substantial flood damage may occur, including regulatory floodplains as designated by FEMA or the Town of Oro Valley. “Zone A (unnumbered)” is a special flood hazard area identified by FEMA that is subject to inundation from a one hundred (100) year flood event. Because detailed hydraulic analyses have not been performed, no base flood elevation or depths are shown. Mandatory flood insurance requirements apply. “Zone AE” is a special flood hazard areas subject to inundation by the one hundred (100) year flood determined by a Flood Insurance Study (FIS). Base flood elevations are shown within these zones and mandatory flood insurance requirements apply. Commented [KK30]: Additional definition, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 12 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. “Zone AH” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding (usually areas of ponding) with average depths between one (1) and three (3) feet. Base flood elevations derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance requirements apply. “Zone AO” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding, usually resulting from sheet flow on sloping terrain, with average depths between one (1) and three (3) feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. Mandatory flood insurance requirements apply. “Zone X shaded” (or “shaded Zone X”) is an area determined by a Flood Insurance Study as having moderate or minimal hazard from flooding. There are four classifications depending on location: (1) area of one hundred (100) year flood with average depths of less than one (1) foot; (2) area with drainage areas less than one (1) square mile; (3) area protected by an accredited levee from one hundred (100) year flood; and (4) area of five hundred (500) year flood. Buildings or other improvements in this zone could be flooded by severe, concentrated rainfall, in the absence of adequate drainage systems. Flood insurance is available in participating communities, but it is not required. In the Town of Oro Valley only the third classification applies (i.e., protected by levees). ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-3 GENERAL PROVISIONS Sections: 17-3-1 Lands to Which This Chapter Applies 17-3-2 Basis for Establishing the Regulatory Floodplain Areas 17-3-3 Compliance 17-3-4 Abrogation and Greater Restrictions 17-3-5 Interpretation 17-3-6 Statutory Exceptions 17-3-7 Floodplain Violations 17-3-8 Abatement of Violations 17-3-9 Unlawful Acts 17-3-10 Remedies 17-3-11 Severability 17-3-12 Warning and Disclaimer of Liability Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 13 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-3-1 Lands to Which This Chapter Applies. This chapter shall apply to all regulatory floodplain areas within the corporate limits of the Town of Oro Valley, including special flood hazard areas, floodplains shown on recorded subdivision plat maps, as well as those areas identified by the Floodplain Administrator, using the best available data. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-2 Basis for Establishing the Regulatory Floodplain Areas. The special flood hazard areas identified by the Federal Emergency Management Agency (FEMA) in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for Pima County, Arizona and Incorporated Areas,” revised September 28, 2012, with accompanying Flood Insurance Rate Maps (FIRMs) dated June 16, 2011, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This Flood Insurance Study (FIS) and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the Floodplain Board by the Floodplain Administrator. The Floodplain Board, within the incorporated limits of the Town of Oro Valley, shall require developers of land to delineate, within areas where development is ongoing or imminent, floodplains consistent with the criteria developed by FEMA, the Arizona Director of Water Resources, and the Town Engineer, pursuant to the Town’s adopted drainage criteria manual. The Flood Insurance StudyFIS and FIRMs are on file at the Town of Oro Valley Public Works Department. A. Regulatory floodplains shall be subject to requirements in Section 17-5-8 (Floodway Fringe Area Requirements). B. Elevation and Boundary Refinements. 1. The determination of elevations (water surface, lowest finished floor, and adjacent land) and regulatory floodway and regulatory floodplain boundaries is an engineering function with calculations and decisions made in accordance with the concepts and policies set forth in this chapter. The best technical data available shall be used for such calculations and decisions. Initial determinations shall be based on floodplain information reports of the Pima County Flood Control District, U.S. Corps of Engineers, U.S. Bureau of Reclamation, U.S. Geological Survey, and/or other general data that are pertinent for the conditions of the streams or the watercourses at the time the data are obtained. 2. Additional and more detailed technical analysis will, from time to time, become available through private or governmental studies and activities. This data will permit refinements in the elevations and boundaries of the regulatory floodway and regulatory floodplains in the respective reaches of the streams or watercourses. Commented [KK31]: Higher standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 14 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 3. Whenever such additional data become available and it seems desirable to make refinements, i.e., letter of map amendments (LOMAs) or letter of map revisions (LOMRs), such refinements or revisions may be made at the request of the property owners or developers or by the Town Engineer. The necessary engineering calculations shall be made for the property owner or developer by an Arizona registered professional engineer (at the owner’s/developer’s expense) in conformance with requirements of this chapter, the FEMA, and the Arizona Department of Water Resources (ADWR). These findings will need approval of the Town Engineer. Following the Town’s approval of these refinements to regulatory floodplain areas identified on FIRMs, the property owner shall have calculations and forms forwarded to FEMA for review and approval. 4. The Town Engineer or their duly designated representative shall have the authority and responsibility to revise and refine elevations and boundaries of regulatory floodways and regulatory floodplains whenever such revisions and refinements are for the purpose and in accordance with the conditions set forth in Sections 17-4-3(B)(1)(d), 17-5-8(B)(3), (4), and (5). a. The Flood Insurance Rate Map for Pima County and incorporated areas shall be revised to show the refined area boundaries and/or elevations. b. The Town Engineer shall notify the owner of each property for which area boundaries and/or elevations have been revised or refined, as well as those owners of adjoining property immediately upstream and downstream, by first class mail following a duly noticed public hearing on the property involved. c. An appeal to the Floodplain Board may be taken by any person aggrieved, in accordance with Article 17-6. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-3 Compliance. All development of land, construction of residential, commercial, or industrial structures, or future development within regulatory floodplain areas is subject to the terms of this chapter and any other applicable regulations. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-4 Abrogation and Greater Restrictions. The provisions of this chapter are not intended to interfere with, abrogate, or annul any ordinance, rule, regulations, or permit previously adopted or issued, and not be in conflict with any provision of this chapter or any regulation that shall be adopted or issued pursuant to law relating to the use of structure or ordinance not in conflict with this chapter; nor is it intended by this chapter to interfere with or abrogate or annul any easement, Commented [KK33]: In addition to State model, no action needed Commented [KK32]: Recommend adding acronym ADWR here Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 15 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. covenant, or other agreement between parties, except when this chapter imposes a greater restriction, this chapter shall control. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-5 Interpretation. In the interpretation and application of this chapter, all provisions shall be: A. Considered as minimum requirements; B. Liberally constructed in favor of the governing body; and C. Deemed neither to limit nor repeal any other powers granted under State statutes. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-6 Statutory Exceptions. A. In accordance with ARS § 48-3609(I), unless expressly provided this and any regulations adopted pursuant to this article do not affect: 1. Existing legal uses of property or the right to continuation of such legal use. However, if a nonconforming use of land or a structure is discontinued for twelve (12) months or destroyed to the extent of fifty percent (50%) or more of its market value, as determined by a competent appraiser, or the valuation made by the Pima County Assessor’s Office, any further use shall comply with this article and regulations of the Town of Oro Valley. 2. Reasonable repair or alteration of property for the purposes for which the property was legally used on August 3, 1984, or any regulations affecting such property takes effect, except that any alteration, addition, or repair to a nonconforming structure which would result in increasing its flood damage potential by fifty percent (50%) or more shall be either flood-proofed or elevated to or above the regulatory flood elevation. 3. Reasonable repair of structures constructed with the written authorization required by ARS § 48-3613. 4. Facilities constructed or installed pursuant to a certificate of environmental compatibility issued pursuant to ARS Title 40, Chapter 2, Article 6.2. B. Before the following types of construction authorized by ARS § 48-3613(B) may begin, the responsible person must submit grading plans and a grading permit application for review and comment. Written authorization is not required for, nor shall the floodplain board prohibit, the following pursuant to ARS § 48-3613(C): Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 16 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 1. The construction of bridges, culverts, dikes, and other structures necessary for the construction of public highways, roads, and streets intersecting or crossing a watercourse. 2. The construction of storage dams for watering livestock or wildlife, structures on banks of a watercourse to prevent erosion of, or damage to, adjoining land, if the structure will not divert, retard or obstruct the natural channel of the watercourse, or dams for the conservation of floodwaters as permitted by ARS Title 45, Chapter 6. 3. The construction of tailing dams and waste disposal areas for use in connection with mining and metallurgical operations. This subsection does not exempt those sand and gravel operations that will divert, retard or obstruct the flow of waters in any watercourse from complying with, and acquiring authorization from, the Town Engineer or the Floodplain Board pursuant to regulations adopted by the Floodplain Board under this article. 4. Other construction, if it is determined by the Town Engineer that a floodplain use permit is unnecessary. 5. Any flood control district, county, city, town, or other political subdivision from exercising powers granted to it under ARS Title 48, Chapter 21, Article 1. 6. The construction, by a public agency or political subdivision, of streams, waterways, lakes, and other auxiliary facilities in conjunction with development of public parks and recreation facilities. 7. The construction and erection of poles, towers, foundations, support structures, guy wires, and other facilities related to power transmission as constructed by any utility, whether a public service corporation or a political subdivision. C. In accordance with ARS § 48-3613(D), in addition to other penalties or remedies otherwise provided by law, the State of Arizona, a political subdivision thereof, or a person who may be damaged or has been damaged as a result of the unauthorized diversion, retardation, or obstruction of a watercourse has the right to go through an administrator/board to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate this section or regulations adopted pursuant to ARS Title 48, Chapter 21, Article 1. If a person is found to be in violation of this section, the administrator/board shall require the violator either to comply with this section, if authorized by the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), or to remove the obstruction and restore the watercourse to its original state. The court may also award such monetary damages as are appropriate to the injured parties resulting from the violation, including reasonable costs and attorney fees. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 17 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-3-7 Floodplain Violations. A. Declaration of Public Nuisance. All development located or maintained within any regulatory floodplain area after August 8, 1973, in violation of this chapter, and without written authorization from the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), is a public nuisance per se, and may be abated, prevented or restrained by action of the Floodplain Board. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-8 Abatement of Violations. Upon discovery of a violation to this chapter, the Floodplain Administrator shall either: A. Take any necessary action to effect the abatement of such violation; or B. Order the owner of the property upon which the violation exists to provide whatever additional information may be required for determination by the Floodplain Administrator. Such information must be provided to the Floodplain Administrator within thirty (30) days of such order. Within thirty (30) days, the Floodplain Administrator shall either order the abatement of said violation or shall grant a variance in accordance with the provisions of Section 17-6-4; or C. For FEMA regulated floodplains (SFHAs), submit to the Federal Emergency Management Agency a declaration for denial of insurance, stating that the property is in violation of a cited State or local law, regulation or ordinance, pursuant to Section 1316 of the National Flood Insurance Act of 1968, and as amended. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-9 Unlawful Acts. A. It is unlawful for a person to engage in any development or to divert, retard, or obstruct the flow of waters in a watercourse if it creates a hazard to life or property without securing the written authorization required by ARS § 48-3613. Where the watercourse is a delineated floodplain, it is unlawful to engage in any development affecting the flow of waters without securing written authorization required by ARS § 48-3613. B. When drainage improvements are associated with an approved development plan, subdivision plat or approved engineering report, and are constructed to provide flood protection to remove or reduce flood hazards, including those identified by FEMA or for stormwater quality control, and where those improvements are privately owned, then it shall be the responsibility of the property owner(s) to perform maintenance as necessary to ensure the integrity of said drainage improvements and maintenance of the flood carrying capacity to the designed discharge. For purposes of this chapter, a private drainage improvement is considered a Commented [KK34]: Recommend removal of A. since there is no B. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 18 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. structure. It is unlawful for any person or entity to neglect maintenance responsibilities on private drainage improvements. C. Any person violating the provisions of this section shall be subject to appeal and variance procedures pursuant to Article 17-6, and penalties pursuant to Article 1-8, Penalties. D. The Town may issue a written notice to correct to any person who has violated or is in violation of this section. E. Failure to comply with actions described in and required by the notice to correct may result in a notice of violation and/or stop work order. The written notice shall state the nature of the violation, the corrective action required, the time frame for the corrective action, and penalties for continued noncompliance. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-10 Remedies. All remedies provided for herein shall be cumulative and not exclusive. The conviction and punishment of any person hereunder shall not relieve such person from the responsibility to correct prohibited conditions or to remove prohibited structures, obstructions, or improvements; nor prevent the enforcement, correction, or removal thereof. In addition to the other penalties or remedies provided in this article, the State of Arizona, any political subdivision thereof, or any person who may be damaged as a result of the diversion, retardation, or obstruction of a watercourse shall have the right to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate any provision of this chapter. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-11 Severability. This chapter, and its various parts thereof, is hereby declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any portion thereof, other than the section so declared to be unconstitutional or invalid. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-3-12 Warning and Disclaimer of Liability. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes, and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the Commented [KK35]: Higher Standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 19 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. regulatory floodplain areas or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the Town of Oro Valley, any officer or employee thereof, the State of Arizona, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-4 ADMINISTRATION Sections: 17-4-1 Establishment of Floodplain Use Permits 17-4-2 Enforcement and Inspection 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures 17-4-4 Designation of the Floodplain Administrator 17-4-1 Establishment of Floodplain Use Permits. A. Responsibility for Permits. It shall be the duty of the Town Engineer acting as the Floodplain Administrator, and all departments, officials, and public employees vested with the duty or authority to issue permits or licenses, to enforce the provisions of this chapter; and no such license or permit shall be issued for uses or buildings where the same would be in conflict with the provisions of this chapter. Any such license or permit, if issued in conflict with the provisions of this chapter, shall be null and void. B. Floodplain Use Permits. It shall be unlawful to erect, construct, reconstruct, alter, or change the use of any structure within any regulatory floodplain area covered by this chapter without first applying for and obtaining a floodplain use permit from the Town Engineer. C. Application for Floodplain Use Permit. Application for a floodplain use permit shall be made on forms furnished by the Town Engineer, and must include, without limitation, plans in duplicate drawn to scale showing the nature, location, dimensions, and elevation of the areas in question; existing or proposed structures including walls, bank protection, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required: 1. Proposed elevation, in relation to mean sea level, of the lowest floor of all structures. In a designated Zone AO, elevation of existing highest adjacent natural grade and proposed elevation of lowest floor of all structures must be obtained; Commented [KK37]: Suggest adding '(including basement)' Commented [KK36]: Higher Permit Standards, No action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 20 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 2. Proposed elevation, in relation to mean sea level, to which any nonresidential structure will be flood-proofed; 3. Certification by an Arizona registered professional engineer or an Arizona registered professional architect that the flood-proofing methods for any nonresidential structure meet the flood-proofing criteria in Section 17-5-1(C); 4. Base flood elevation data shall be provided for subdivisions or other developments greater than fifty (50) lots or five (5) acres, whichever is the lesser; and 5. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. Each such application shall be accompanied by an application fee, as set forth by the Town, payable to the Town of Oro Valley. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-4-2 Enforcement and Inspection. A. Enforcement. It shall be the duty of the Floodplain Administrator and officials of the Town otherwise charged with the enforcement of the law, to enforce this chapter and all of the provisions of the same. B. Inspections. Inspections shall be made by officials of the Town duly appointed by the Town Engineer or by a duly appointed Floodplain Administrator. C. Cooperation. The Town Floodplain Administrator may request, and shall receive so far as may be necessary in the discharge of their duties, the assistance and cooperation of all departments, agencies, officials, and public employees vested with the duty or authority to issue permits, licenses, or to enforce the regulations of this chapter. D. Town of Oro Valley Administration. Hydrologic, hydraulic, and related floodplain regulations, as well as engineering matters pertaining to the administration and direction of this chapter, shall be referred to the Town of Oro Valley Town Engineer or their designated representative, who shall be responsible for such reviews, advice, and recommendations. E. Cooperation Agreements and Consultants. The Floodplain Administrator, through the applicable procurement and/or intergovernmental agreement procedures, may retain consultants and experts; and may enter into cooperative agreements for the delineation of floodplains and floodways as well as for such other assistance and guidance considered appropriate and necessary to obtain maximum reasonable protection and benefits under this chapter. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK38]: In addition to State model, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 21 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures. A. The Floodplain Administrator shall issue floodplain use permits required by this section. B. The following procedure shall be used by the Floodplain Administrator in considering issuance of floodplain use permits: 1. Upon receiving an application for a floodplain use permit involving the use of fill, construction of structures, or the storage of materials, and prior to rendering a decision thereon the Floodplain Administrator may: a. Require the applicant to submit, where applicable, plans in triplicate drawn to scale showing the nature, location, dimensions, and elevations of the lot; existing or proposed structures, fill, storage of materials, flood-proofing measures; and the relationship of the above to the location of the channel, regulatory floodway, regulatory floodplain, the regulatory floodplain with base flood elevations, the proposed project in relation to flood heights and velocities, and the plans for flood protection. The applicant shall provide a new delineation of all regulatory floodplains affected by the project. The new delineation and reports shall be prepared in conformance with FEMA requirements and this chapter. The delineation shall show pre- and post-project floodplain limits and water surface elevations upstream, adjacent, and downstream of the project. b. Require, where circumstances necessitate more detailed information, the applicant to furnish as much of the following additional information as is deemed necessary by the Floodplain Administrator for the evaluation of the effects of the proposed use upon flood flows and the consideration of other factors necessary to render a decision on suitability of the proposed use: i. A typical valley cross-section showing the floodway, floodway fringe area, and the floodplain of the watercourse; elevation of land areas adjoining each side of the channel; cross-sectional areas to be occupied by the proposed development; and high water information; ii. A plan (surface view) showing elevations or contours of the ground; pertinent structure, fill or storage elevations; size, location, and spatial arrangement of all proposed and existing structures on the site; location and elevations of streets, water supply, sanitary facilities; photographs showing existing land uses and vegetation upstream and downstream, and soil types, as well as other pertinent information; iii. A profile showing the slope of the bottom of the channel or flow line of the watercourse; iv. Specifications for building construction and materials, flood-proofing, filling, dredging, grading, channel improvement, storage of materials, water supply, and sanitary facilities. c. Ensure that the proposed development does not adversely affect the carrying capacity of channels at locations where base flood elevations have been determined but a floodway has not been designated. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 22 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. d. For FEMA regulated floodplains (SFHAs), require the applicant to submit appropriate (e.g., CLOMR, CLOMR-F, LOMR, etc.) applications, forms, and information to FEMA for review and approval. A floodplain use permit shall not be issued by the Town of Oro Valley until after receiving acknowledgement from FEMA of the acceptance of the CLOMR. Additionally, final building permit inspections shall not be made, nor shall certificates of occupancy be given, until after receiving acknowledgement from FEMA that the LOMR has become effective. e. Ensure other related State of Arizona and Federal permits have been issued. 2. No permit shall be issued for any development that is not in conformance with this chapter, FEMA regulations, or some other provision of law relating to such development. A floodplain use permit may be denied if the proposed development constitutes a danger or hazard to life or property. C. The Floodplain Administrator shall be responsible for the following duties: 1. Obtain and maintain for public inspection and make available the following: a. Certification of the regulatory flood elevation required in Sections 17-5-1(C)(1), 17-5-1(C)(2), and 17-5-5; b. The Zone AO certification required in Section 17-5-1(C)(2); c. The flood-proofing certification required in Section 17-5-1(C)(3); d. The certified opening elevation required in Section 17-5-1(C)(4); e. Review all development permits for improvements and/or damages to existing structures to determine if the application of the substantial improvement rules apply, including establishing a definition of market value determination and verifying that the estimated improvement and/or repair costs are less than fifty percent (50%) of the market value of the structure; f. Certification of elevation for subdivisions required by Section 17-5-4(E); g. Certification for floodway encroachments required by Section 17-5-7(A); h. Records of all variance actions, including justification for their issuance required by Section 17-6-3(C). 2. Notification of other entities: a. Notify adjacent communities and ADWR prior to such alteration or relocation of a watercourse, and submit evidence of such notification to FEMA through appropriate notification means; and b. Require that the flood carrying capacity of the altered or relocated portion of said watercourse be maintained. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 23 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 3. Within one hundred twenty (120) days after completion of construction of any flood control protective works which change the rate of flow during the flood or the configuration of the floodplain upstream or downstream from or adjacent to the project, the person or agency responsible for installation of the project shall provide to the governing bodies of all jurisdictions affected by the project a new delineation of all floodplains affected by the project. The new delineation shall be done according to the criteria adopted by the ADWR. 4. Advise the Pima County Regional Flood Control District and any adjunct jurisdiction having responsibility for floodplain management in writing and provide a copy of a development plan of all applications for floodplain use permits or variances to develop land in a floodplain or floodway within one (1) mile of the corporate limits of the Town of Oro Valley, Arizona. Also, advise the Pima County Regional Flood Control District in writing and provide a copy of any development plan of any major development proposed within a floodplain or floodway, which could affect floodplains, floodways or watercourses within the district’s area of jurisdiction. Written notice and a copy of the plan of development shall be sent to the district no later than three (3) working days after having been received by Town of Oro Valley. 5. Notify FEMA of acquisition by means of annexation, incorporation or otherwise, of additional areas of jurisdiction. 6. A community’s base flood elevations may increase or decrease resulting from physical changes affecting flooding conditions. As soon as practicable, but not later than six (6) months after the date such information becomes available, a community shall notify FEMA of the changes by submitting technical or scientific data in accordance with 44 CFR 65.3. Such a submission is necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements will be based upon current data. 7. Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 17-3-2 (Basis for Establishing the Regulatory Floodplain Areas), the Floodplain Administrator shall obtain, review and reasonably utilize any base flood elevation data available from a Federal, State, or other source, in order to administer Section 17-5-1 (Standards of Construction). Any such information shall be consistent with the requirements of the Federal Emergency Management Agency and the Director of the Arizona Department of Water Resources and may be submitted to the Floodplain Board for adoption. 8. Make map interpretations, where needed, as to the exact location of the boundaries of the special flood hazard areas (e.g., where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Article 17-6 (Appeal and Variance Procedures). 9. Take remedial actions on violations of this chapter as required in Section 17-3-8 (Abatement of Violations). ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK39]: In addition to State model, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 24 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-4-4 Designation of the Floodplain Administrator. The Town Engineer or their designee is hereby appointed to administer, implement, and enforce this chapter and guidelines set forth in this article by processing floodplain use permits in accordance with its provisions. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-5 PROVISIONS FOR FLOOD HAZARD REDUCTION Sections: 17-5-1 Standards of Construction 17-5-2 Standards for Storage of Materials and Equipment 17-5-3 Standards for Water Supply and Waste Disposal Systems 17-5-4 Standards and Submittal Requirements for Subdivisions 17-5-5 Standards for Manufactured Homes 17-5-6 Standards for Recreational Vehicles 17-5-7 Floodways 17-5-8 Floodway Fringe Area Requirements 17-5-9 Flood-Related Erosion-Prone Area 17-5-1 Standards of Construction. In all regulatory floodplain areas, the following standards are required: A. Anchoring. 1. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. 2. All manufactured homes shall meet the anchoring standards of Section 17-5-5(B). B. Construction Materials and Methods. 1. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. 2. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 25 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 3. All new construction, substantial improvements, and other proposed new development shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment, as well as other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding. 4. Within Zone AH or AO, adequate drainage paths around structures on slopes are required to guide floodwaters around and away from proposed structures. C. Elevation and Flood-Proofing. 1. New construction and substantial improvement of any structure shall have the lowest floor, including basement, elevated at or above the regulatory flood elevation. In areas without a detailed study but within regulatory floodplain boundaries, the applicant shall have an Arizona registered professional engineer prepare a detailed study to determine the depth of the base flood. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure, the elevation of the lowest floor, including basement, shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor, and provided to the Floodplain Administrator and the Town Building Official. 2. New construction and substantial improvement of any structure in Zone AO shall have the lowest floor, including basement, higher than the highest adjacent grade at least one (1) foot higher than the depth number on the FIRM, or at least two (2) feet if no depth number is specified. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon completion of the structure an Arizona registered professional engineer or Arizona registered professional land surveyor shall certify to the Floodplain Administrator that the elevation of the structure meets this standard. 3. Nonresidential construction and new and substantial improvement of any structure shall either be elevated in conformance with subsections (C)(1) and (2) of this section, or together with attendant utility and sanitary facilities: a. Be flood-proofed so that below the regulatory flood elevation the structure is watertight with walls substantially impermeable to the passage of water; b. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and c. Be certified by an Arizona registered professional engineer or an Arizona registered professional architect that the standards of this subsection are satisfied. Such certifications shall be provided to the Floodplain Administrator and the Town Building Official. 4. Require, for all new construction and substantial improvements of nonresidential structures, that have fully enclosed areas below the regulatory flood elevation that are usable solely for parking of vehicles, building access, or storage in an area other than a basement, and which are subject to flooding, shall be constructed of flood resistant materials to the regulatory flood elevation, have all service facilities Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 26 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. elevated at or above the regulatory flood elevation, and be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by an Arizona registered professional engineer or an Arizona registered professional architect or meet or exceed the following minimum criteria: a. A minimum of two (2) openings, on different sides of each enclosed area, shall be provided having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. Smaller engineered openings may be allowed if the design is supported by a certification report issued by ICC-ES (International Code Council Evaluation Service), or an equivalent product certification organization. b. The bottom of all openings shall be no higher than one (1) foot above grade. c. Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters. 5. Manufactured homes shall meet the standards in Section 17-5-5. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-5-2 Standards for Storage of Materials and Equipment. A. The storage or processing of materials is prohibited if they are, in time of flooding: buoyant, flammable, explosive, or could be noxious, deadly, or injurious to human, animal, or plant life. B. Storage of other material or equipment may be allowed if they are not subject to major damage by floods, or if they are firmly anchored to prevent flotation, or if they are readily removable from the area within the time available after flood warning. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-5-3 Standards for Water Supply and Waste Disposal Systems. A. All new or replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from systems into floodwaters. B. On-site waste disposal systems shall not be installed wholly or partially in a regulatory floodway, erosion setback, or as established by ADEQ, whichever is most restrictive. C. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK40]: Higher standard, no action needed Commented [KK41R40]: ADEQ acronym defined? Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 27 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-5-4 Standards and Submittal Requirements for Subdivisions. A. All new subdivision proposals and other proposed development (including proposals for manufactured home parks and subdivisions), greater than fifty (50) lots or five (5) acres, whichever is the lesser, shall: 1. Identify the regulatory floodplain area and the elevation of the base flood; and 2. Identify on the final plans the elevation(s) of the proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and grade elevations shall be certified by an Arizona registered professional engineer or Arizona registered professional land surveyor and provided to the Floodplain Administrator. B. All subdivision proposals shall be consistent with the need to minimize flood damage. C. All subdivision proposals (also referred to as a final site plan) shall have all public utilities and facilities, including but not limited to sewer, gas, electrical, and water systems, located and constructed to minimize flood damage. D. All subdivisions shall provide adequate drainage to reduce exposure to flood hazards (see adopted drainage criteria manual). E. Suitability of the Land. Land that has been found by the Floodplain Board to be unsuitable for development with permanent structures based on hydrological and engineering studies of flooding can be platted and used only for open space and greenbelt uses such as those identified in Section 17-5-7(B)(1). This includes land which is: 1. Physically unsuitable because of flooding, poor drainage, and other features which may endanger health, life, or property, aggravate erosion, increase the flood hazard, or increase the burden imposed on the community, its governmental units, and its citizens; 2. Subject to flooding because of its proximity to the stream or watercourse; or because of low elevation. In applying this provision, the Floodplain Board, with technical support and recommendations from the Town Engineer, shall consider: a. Land subject to flooding by the base flood shall not be platted for residential occupancy, or building sites, or for any other uses that may increase the flood hazard or endanger health, life, or property, unless each lot contains a building site that meets requirements set forth below, in subsections (G) and (H) of this section, and within other pertinent sections of this chapter; b. Fill shall not be used to raise land within the regulatory floodway. In other areas subject to flooding by the base flood, fill may be used; provided, that the proposed fill does not restrict the flow of water and increase flood heights or velocities in the regulatory floodway, according to the same standards established in Section 17-5-8; and provided, that compensatory flood storage is provided. F. Flood Situation to Be Shown on Plat. Plats submitted shall show the following: Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 28 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 1. Conceptual site development plans (plats) shall show the location, by survey, of watercourses, channels, irrigation laterals, private ditches, culverts, lakes, or other water features, including direction of flow, water level elevations, and the location and extent of areas subject to frequent inundation; 2. All preliminary subdivision proposals shall identify the special flood hazard areas, regulatory floodplain, the elevation of the base flood, pre- and post-development water surface elevations, and pre- and post-development floodplain limits; 3. All conceptual and final subdivision plans will provide the elevation(s) of proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and pad elevation shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor and provided to the Floodplain Administrator and the Town Building Official; 4. Final plats shall show the limits of the regulatory floodplain and the regulatory floodway, as well as the corresponding one hundred (100) year flood peaks, and their contributing drainage areas, entering and exiting the development; 5. Conceptual and final site plans shall show proposed improvements for areas subject to flooding and/or for areas which contain extremely poor drainage facilities such that the proposed improvements make the areas safe from flooding for the respective type of occupancy. G. Street Elevations. 1. Refer to the Town’s adopted drainage criteria manual and subdivision street standards for additional information and requirements. 2. Fill used for the streets in areas subject to flooding shall not increase flood heights more than a designated amount as defined in Section 17-5-8(A)(1)(b). 3. The developer shall provide pre- and post-developed water surface elevation for streets proposed for placement in or adjacent to areas subject to flooding. Headwater ponding limits and water surface elevations shall be shown upstream of all culvert crossings. H. Building Site. 1. Residential lots shall contain a building site, either natural or manmade, which is not subject to flooding by the base flood. 2. In areas subject to flooding by the base flood, where no fill is proposed, the building line shall be located no closer to the watercourse or channel than the edge of the area subject to flooding by the base flood. In areas where fill is used to raise the elevation of the building site, no fill shall be placed in the regulatory floodway. Further, where fill is used, the erosion setback shall not be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for protected banks. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 29 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. I. Setback from Channels. Along reaches of all regulated watercourses, erosion setback requirements from banks of washes shall be established in accordance with the Town’s adopted drainage criteria manual or standards accepted by the Town Engineer. J. Easements for Drainage. Whenever any watercourse is located in the area being subdivided, an easement or common area encompassing each side of the watercourse shall be provided for the purpose of protecting and/or maintaining the watercourse for flood and drainage purposes, and such further width for construction of bank protection, physical access for maintenance, or for allowing for natural meander of the stream or watercourse that may be reasonably expected, or for all these as will be adequate for the purpose, as determined by the Town Engineer. K. Detention/Retention Systems. See Town’s adopted drainage criteria manual for requirements pertaining to detention/retention systems by visiting the administrative offices of the Town of Oro Valley. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-5-5 Standards for Manufactured Homes. All manufactured homes that are placed within or substantially improved while located within a regulatory floodplain shall apply for and obtain a floodplain use permit summarizing site conditions including base flood elevation, depth of the base flood, and minimum prudent erosion setback. The application for a floodplain use permit shall be accompanied by a site plan, prepared by an Arizona registered engineer, that conforms to the State of Arizona Office of Manufactured Housing, “Minimum Standards for Manufactured Housing Foundations in Floodplains,” dated October 14, 2009, or as subsequently amended. Accessory structures attached to a manufactured home must meet the provisions of this chapter unless its uses are limited to parking of vehicles or storage. Furthermore, manufactured homes shall: A. Be elevated so that the lowest structural member or the lowest point of any attached appliances, whichever is lower, is at or above the regulatory flood elevation. Pit-set installations are prohibited whenever the lowest structural member or appliance is below the regulatory flood elevation; B. Be securely anchored to an adequately anchored foundation system to resist flotation, collapse, or lateral movement. This anchoring requirement is in addition to applicable State and local anchoring requirements for resisting wind forces; and C. Upon completion of installation of the manufactured home, certification by an Arizona registered professional engineer or Arizona registered professional land surveyor that the elevation requirements of this section have been satisfied shall be provided to the Floodplain Administrator for verification. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Commented [KK44]: Recommend deleting. In general, pit-set installations are prohibited in SFHAs. Commented [KK43]: Higher standard, no action needed Commented [KK42]: Higher standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 30 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-5-6 Standards for Recreational Vehicles. All recreational vehicles placed within a regulatory floodplain area will either: A. Be on site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use, to the extent that they are not prohibited by any other ordinance. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions; or B. Meet the permit requirements of Article 17-4, and the elevation and anchoring requirements for manufactured homes in Section 17-5-5. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-5-7 Floodways. Located within regulatory floodplain areas, established in Section 17-3-2, are areas designated as regulatory floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris, potential projectiles, and increase erosion potential, the following provisions apply: A. Encroachments, including fill, new construction, substantial improvements, and other development are prohibited in floodways. The Floodplain Administrator will consider encroachments where certification by an Arizona registered professional engineer is provided demonstrating that encroachments will result in no increase whatsoever in flood levels during the occurrence of the base flood discharge, and that the encroachment will not pose a threat to life or property. B. Floodway Requirements. 1. Uses Permitted. The following open space uses shall be permitted to the extent that they are not prohibited by any other ordinance or State or Federal permit requirements, nor conflict with uses permitted in adjoining zones, and provided they do not require structures, fill, or storage of materials or equipment: a. Agricultural uses, including general farming, pasture, grazing or outdoor plant nurseries, horticulture, viticulture, truck farming, sod farming, wild crop harvesting, and restoration of native vegetation; b. Private and public recreational uses; c. Accessory residential uses, including lawns, gardens, and play areas. C. Limitations. 1. No use shall be allowed within a regulatory floodway which: Commented [KK45]: Higher standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 31 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. a. Acting alone or in combination with existing or future uses creates a danger or hazard to life or property; b. Increases the water surface elevation of the base flood; or c. Adversely affects groundwater recharge. D. If this section is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions in this article. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-5-8 Floodway Fringe Area Requirements. A. Floodway fringe areas shall be subject to the following regulations: 1. The following uses shall be permitted within a floodway fringe area to the extent that they are not prohibited by any other ordinance, and only upon issuance of a floodplain use permit: a. Any use permitted in Section 17-5-7, Floodways; b. Any other use not involving structures, provided it is elevated above the regulatory base flood elevation and a determination is made by the Town Engineer that the use will not increase the base flood elevation more than one (1) foot where the owner of the land doing the development owns both sides of the floodway, and not more than one-tenth (0.1) foot where only one (1) side is owned. In no case shall the development increase the water surface elevation more than one-tenth (0.1) foot on the property owned by others upstream and downstream, nor unduly restrict the capacity of the channels or floodway of tributaries to the main stream or watercourse, drainage ditches, or other drainage facilities or systems. The aforementioned water surface elevation increases apply to all watercourse channels in Oro Valley except the Canada del Oro Wash where the elevation of the existing levee system and bank protection will allow for no water surface elevation increases due to encroachment. Additionally, when main channel floodflow velocities are greater than four (4) feet per second (fps), a land use/development activity shall not increase floodflow velocities immediately downstream of the activity by more than one (1) fps or ten percent (10%), whichever is less, in the regulatory floodway. Any velocity increase greater than the aforementioned criteria must be reviewed and approved by the Town Engineer; c. Structures, including dwellings, may be erected or moved, provided the lowest floor or basement floor is placed at or above the regulatory flood elevation. Land may be filled; provided, that the top of such fill shall be at or above the regulatory flood elevation for the particular area, and unless structurally protected from erosion shall extend at such elevations at least twenty-five (25) feet beyond the limits of any structure erected or placed thereon. Where structural protection from erosion is provided, the minimum extent to which tops of the fill pad must extend shall not be less Commented [KK47]: Higher standard, no action required Commented [KK46]: Higher standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 32 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. than fifteen (15) feet. The placement of structures and any accompanying fill shall not affect base flood elevation beyond the limits set in subsection (A)(1)(b) of this section. B. The following minimum requirements apply to all uses located within a regulatory floodplain: 1. All new construction (including prefabricated structures and mobile homes) and substantial improvements shall be anchored to prevent flotation and lateral movement, and be constructed with flood resistant materials and methods. 2. All proposed plats and proposals for other developments, including their utilities, streets, and drainage structures, shall be located and designed to be consistent with the need to minimize flood damage. 3. All tentative development plans, site plans, final site plans, improvement plans, and final plats, and other proposed new developments shall include base flood elevation data or as otherwise directed by the Town Engineer. 4. If in a riverine situation, all adjacent communities and the State Coordinating Office must be notified prior to any alteration or relocation of the watercourse, and copies of such notifications must be sent to the FEMA. Within the proposed altered or relocated portion of any watercourse, the flood carrying capacity shall be maintained. 5. Within one hundred twenty (120) days after completion of construction of any flood control protective works which changes the rate of flow during the flood, or changes the configuration of the floodplain, the person or agency responsible for installation of the protective works shall provide to the governing bodies of all jurisdictions affected by the protective works a new delineation of all floodplains affected. The new floodplain delineation shall be done according to the criteria adopted by the State of Arizona Director of Water Resources. C. Limitations. 1. No use shall be allowed within a floodway fringe which: a. Acting alone or in combination with existing or future uses creates danger or hazard to life or property; b. Increases the water surface elevation for the base flood by more than that allowed under subsection (A)(1)(b) of this section; c. Adversely affects groundwater recharge. D. Critical Facilities. 1. “Critical facility” means any of the following: Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 33 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. a. A structure or facility that produces, uses or stores highly volatile, flammable, explosive, toxic, and/or water-reactive materials; b. Hospitals, emergency medical facilities, nursing homes and/or housing facilities likely to have occupants who may not be sufficiently mobile to avoid injury or death during a flood; c. Essential emergency response facilities, such as police stations, fire stations, emergency shelters and/or operation centers that are needed for public safety and/or flood response activities before, during and after a flood; and d. Public and private utility facilities, such as but not limited to power, water and wastewater treatment, and/or communications, that are vital to maintaining or restoring normal services to flooded areas before, during and after a flood. 2. Applicability. The critical facility requirements shall only apply along watercourses which have FEMA designated floodplains. Where the two-tenths percent (0.2%) chance floodplain has not been established, the Town Engineer may require that this floodplain be delineated by the applicant. 3. Critical facilities shall be located outside of the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, if possible. If a critical facility must be located in a two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, it must be demonstrated that there is either a critical need to locate it within the floodplain, or that there is not a suitable alternative site, as justified by an Arizona registered professional engineer. Any critical facility located within a two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain shall be protected from that event. “Protection” includes, but is not limited to, elevating the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all weather access during the base flood and developing an emergency response plan. 4. Existing critical facilities within the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain that propose substantial improvements and/or repairs shall be protected from the two-tenths percent (0.2%) annual chance (five hundred (500) year) flood event. “Protection” includes, but is not limited to, elevating or flood-proofing the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all-weather access to the base flood and developing an emergency response plan. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 34 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-5-9 Flood-Related Erosion-Prone Area. The protection of Town residents and their property from injury and damage that can occur as a result of streambank lateral migration due to erosion and scour is of primary importance in the administration of this chapter and the following criteria apply: A. The Floodplain Administrator shall require Floodplain Use Permits for proposed construction and other development within all flood-related erosion-prone areas, as determined by lateral migration analysis described in the Town’s drainage criteria manual or in other predetermined, documented evidence. Areas generally most susceptible to lateral erosion and scour include, but are not limited to, locations of historical stream/wash meandering, locations where poorly defined or poorly consolidated banks occur, wash reaches characterized by changes in the direction, velocity, or amount of streamflow, and locations in the proximity of stabilizing features or structures such as rock outcrops or bridges. Alternative safe limits for erosion setbacks may be considered if approved in writing by the Floodplain Administrator based on an acceptable engineering study prepared and sealed by an Arizona registered professional engineer. However, at no time shall a setback be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for a protected bank. B. Permit applications shall be reviewed to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion, and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard. C. If a proposed development or structure including associated permanent features such as a patio wall or swimming pool or any other feature is found to be in the path of flood-related erosion, or would increase the erosion hazard, such improvements shall be relocated or adequate protective measures shall be taken to avoid aggravating the existing erosion hazard. D. Areas within the erosion setback may be used for suitable open space purposes, such as for outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-6 APPEAL AND VARIANCE PROCEDURES Sections: 17-6-1 Nature of Variances 17-6-2 Floodplain Board 17-6-3 Appeals and Request for Variance Considerations 17-6-4 Conditions for Variances Commented [KK48]: Higher standard, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 35 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 17-6-1 Nature of Variances. The variance criteria set forth in this article are based on the general principle of zoning law that variances pertain to a piece of property and are not personal in nature. A variance may be granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter would create an exceptional hardship to the applicant or the surrounding property owners. The characteristics must be unique to the property and not be shared by adjacent parcels. The unique characteristic must pertain to the land itself, not to the structure, its inhabitants, or the property owners. It is the duty of the Town of Oro Valley to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring a structure built below the regulatory flood elevation are so serious that variances from the regulatory flood elevation shall not be granted. Variances from other requirements in the floodplain management ordinance are quite rare. The long-term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-6-2 Floodplain Board. A. The Floodplain Board of Oro Valley shall hear and decide requests for variances from the requirements of this chapter to FEMA regulated floodplains, as well as hear appeals to decisions from previous determinations or actions on non-FEMA regulated floodplains by the Floodplain Administrator or the Town Engineer. B. The Floodplain Board shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Floodplain Administrator in the enforcement or administration of this chapter with regard to FEMA regulated floodplains and floodplains identified on the Town’s Flood Insurance Rate Maps. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-6-3 Appeals and Request for Variance Considerations. A. In considering appeals and requests for variance, the Floodplain Board shall consider all technical evaluations, all relevant factors, and all standards specified in other sections of this chapter, and also consider: 1. The danger that materials may be swept onto other lands to the injury of others; 2. The danger of life and property due to flooding or erosion damage; Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 36 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. 3. The susceptibility of the proposed facility and its contents to flood damage, and the effect of such damage on the individual owner; 4. The importance of the services provided by the proposed facility to the community; 5. The necessity to the facility of a waterfront location, where applicable; 6. The availability of alternative locations for the proposed use that are not subject to flooding or erosion damage; 7. The compatibility of the proposed use with existing and anticipated development; 8. The relationship of the proposed use to the comprehensive plan and floodplain management program for the area encompassing the proposed use; 9. The safety of access to the property in time of flood for ordinary and emergency vehicles; 10. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and 11. The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, water system, and streets and bridges. B. Upon consideration of the factors of subsection (A) of this section and the purposes of this chapter, the Floodplain Board may attach such conditions to the granting of appeals and variances as it deems necessary to further the purposes of this chapter. C. The Floodplain Administrator shall maintain a record of all variance actions, including justification for their issuance, and shall report any such variances that are issued in FEMA regulated floodplains in its biennial report, which is also submitted to the Federal Emergency Management Agency. D. Any applicant to whom a variance is granted shall be given written notice over the signature of the Floodplain Administrator, or their designee, that: 1. The issuance of a variance to construct a structure below the base flood elevation will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage; and 2. Such construction below the regulatory flood elevation increases risks to life and property; and 3. The land upon which the variance is granted shall be ineligible for exchange of State land pursuant to the flood relocation and land exchange program provided by ARS § 37-610. A copy of the notice shall be recorded in the office of the Pima County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. Commented [KK49]: Recommend deleting. State land exchange program is no longer active. Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 37 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. E. A person aggrieved in any manner by an action of the Floodplain Board may within thirty (30) days appeal to the Floodplain Board. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) 17-6-4 Conditions for Variances. A. Variances shall only be issued upon: 1. A showing of good and sufficient cause; 2. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief; 3. A determination that failure to grant the variance would result in exceptional hardship to the applicant; 4. A showing that the use cannot perform its intended purpose unless it is located or carried out in close proximity to water. This includes only facilities defined in Article 17-2 in the definition of “functionally dependent use” (which is unlikely due to the Town of Oro Valley’s arid climate); and 5. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances. B. Variances shall not be issued within any regulatory floodway if any increase in the base flood elevation would result. C. Variances may be issued for the repair, rehabilitation, or restoration of structures listed in the National Register of Historic Places or the State Inventory of Historic Places upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as a historic structure, and that the variance is the minimum necessary in order to preserve the historic character and design of the structure. D. The Floodplain Administrator, at his/her discretion, may grant a variance for non-FEMA regulated flood hazard areas. E. Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (0.5) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the regulatory flood elevation, provided the procedures of Articles 17-4 and 17-5 have been fully considered. As the lot size increases beyond one-half (0.5) acre, the technical justification required for issuing the variance increases. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 38 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. Article 17-7 ORDINANCE AMENDMENTS Sections: 17-7-1 Procedures 17-7-1 Procedures. A. The Floodplain Board may from time to time, after a public hearing required by law (ARS § 38-431.01, and other open meeting laws), amend, supplement, or change the regulations set forth herein or subsequently established. Any amendment, supplement, or change may be initiated by the Floodplain Board or by petition of affected persons hereafter provided. B. The procedures established by this article are to provide for appropriate and timely ordinance amendments, with due consideration of the purpose of this article. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) Article 17-8 FEES Sections: 17-8-1 Fee Schedule 17-8-1 Fee Schedule. Fees for floodplain use permits will be charged based on the fee schedule approved by the Town Council. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005) The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. Disclaimer: The Town Clerk’s Office has the official version of the Oro Valley Town Code. Users should contact the Town Clerk’s Office for ordinances passed subsequent to the ordinance cited above. Commented [KK51]: In addition to State model, no action needed Commented [KK50]: In addition to State model, no action needed Chapter 17 Floodplain and Erosion Hazard Management | Oro Valley Town Code Page 39 of 39 The Oro Valley Town Code is current through Ordinance (O)22-09, passed October 5, 2022. Town Website: www.orovalleyaz.gov Code Publishing Company Created: 2023-03-06 By: Status: Transaction ID: Keith Krukowski (kkrukowski@azwater.gov) Signed CBJCHBCAABAA_tZEmMhT7srl_m3GcJlkGqxa096zwRyl 20230119OroValleyCAV_ReportFinal Final Audit Report 2023-03-06 "20230119OroValleyCAV_ReportFinal" History Document created by Keith Krukowski (kkrukowski@azwater.gov) 2023-03-06 - 6:29:03 PM GMT Document e-signed by Keith Krukowski (kkrukowski@azwater.gov) Signature Date: 2023-03-06 - 6:30:15 PM GMT - Time Source: server Document emailed to Brian Cosson (btcosson@azwater.gov) for signature 2023-03-06 - 6:30:17 PM GMT Email viewed by Brian Cosson (btcosson@azwater.gov) 2023-03-06 - 6:48:19 PM GMT Document e-signed by Brian Cosson (btcosson@azwater.gov) Signature Date: 2023-03-06 - 6:53:53 PM GMT - Time Source: server Agreement completed. 2023-03-06 - 6:53:53 PM GMT Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 1 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. CHAPTER 17 FLOODPLAIN AND EROSION HAZARD MANAGEMENT Articles: 17-1 Statutory Authorization, Findings of Fact, Purpose and Methods 17-2 Definitions 17-3 General Provisions 17-4 Administration 17-5 Provisions for Flood Hazard Reduction 17-6 Appeal and Variance Procedures 17-7 Ordinance Amendments 17-8 Fees Article 17-1 STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS Sections: 17-1-1 Statutory Authorization 17-1-2 Findings of Fact 17-1-3 Statement of Purpose 17-1-4 Methods of Reducing Flood Losses 17-1-1 Statutory Authorization. The Legislature of the State of Arizona has, in ARS § 48-3610, enabled the Town of Oro Valley to assume the powers and duties for floodplain management and adopt regulations in conformance with ARS § 48-3609 that are designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the Town Council of Oro Valley, Arizona, does ordain as follows. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-2 Findings of Fact. A.  The regulatory floodplains of Oro Valley are subject to periodic inundation that may result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 2 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare. B.  These flood losses are caused by the cumulative effect of obstructions in regulatory floodplains, which increase flood heights and velocities. Also, when these obstructions are inadequately anchored, they may cause damage in other areas. Uses that are inadequately flood-proofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-3 Statement of Purpose. It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed: A.  To protect human life and health; B.  To minimize expenditure of public money for costly flood control projects; C.  To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; D.  To minimize prolonged business interruptions; E.  To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone, and sewer lines, and streets and bridges located in regulatory floodplains; F.  To help maintain a stable tax base by providing for the sound use and development of the regulatory floodplain special flood hazard areas and erosion hazard areas so as to minimize blight areas caused by flooding; G.  To ensure the state mandated required regulatory floodplain information is available to potential buyers; H.  To regulate activities within regulatory floodplains for both public and private properties; I.  To participate in and maintain eligibility for flood insurance and disaster relief. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-4 Methods of Reducing Flood Losses. In order to accomplish its purposes, this chapter includes methods and provisions for: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 3 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. A.  Restricting or prohibiting uses which are dangerous to the public health, safety, and welfare as well as public and private property, due to water or development hazards; or which result in increased damages to development or increases in flood heights or velocities; B.  Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of start of construction; C.  Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help to accommodate natural flood storage potential or the channelization of floodwaters; D.  Controlling filling, grading, dredging, and other development that may increase flood damage; and E.  Preventing or regulating the construction of flood barriers that unnaturally divert floodwaters, or that may increase flood hazards in other areas. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) Article 17-2 DEFINITIONS Sections: 17-2-1 Definitions 17-2-1 Definitions. Unless specifically defined below, words or phrases used in this chapter shall be interpreted to give them the meaning they have in common usage, and to give this chapter its most reasonable application. “Accessory structure” means a structure that is on the same parcel of property as a principal structure, the use of which is incidental to the use of the principal structure. For floodplain management purposes, the term must be used only for parking or storage, must be small, represent a minimal investment, and have low damage potential. FEMA considers ‘small’ to mean not larger than a one-story two-car garage. Examples include detached garages, storage sheds, tool sheds, and small boathouses. “Appeal” means a request for a review of the Floodplain Administrator’s interpretation of any provision of this chapter or a request for a variance. Appeals are heard and decided by the Floodplain Board. “Area of shallow flooding” means a designated zone AO or AH on a community’s Flood Insurance Rate Map (FIRM) with a one percent (1%) or greater annual chance of flooding to an average depth Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 4 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. of one (1) to three (3) feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. “Base flood” means a flood having a one percent (1%) chance of being equaled or exceeded in any given year. “Base flood elevation (BFE)” means the computed elevation to which floodwater is anticipated to rise during the base flood. “Basement” means any area of a structure with a subgrade floor (i.e., below the adjacent ground level) on all sides. Building. See “Structure.” “Community” means any state or area or political subdivision thereof, or any Indian tribe, authorized tribal organization, or authorized Native organization, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction. Critical Facility. Refer to Section 17-5-8(D). “Detention system” means a type of flood control system which delays the downstream progress of floodwaters in a controlled manner, generally through the combined use of a temporary storage area and a metered outlet device, which causes a lengthening of the duration of the flow and thereby reduces downstream flood peaks. “Development” means any manmade change to improved or unimproved real estate, including but not limited to structures, mining, dredging, filling, grading, paving, excavation or drilling operations, and storage of materials and equipment. “Dwelling” means a habitable structure. “Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that is used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a letter of map amendment (LOMA) or letter of map revision based on fill (LOMR-F). “Encroachment” means the advance or infringement of uses, human-installed or human-maintained landscape vegetation, fill, excavation, permanent structures, or development into a floodplain that may impede or alter the flow capacity of a floodplain. An equal degree of encroachment is a standard applied to the evaluation of the effects of the encroachment on increases in flood heights. It assumes that an encroachment, if permitted, may confer on all property owners on both sides of the watercourse an equal right to encroach to the same degree within that reach. Since the factors affecting hydraulic efficiency are usually not uniform within a reach, this standard will usually not Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 5 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. result in equal measured distances between the regulatory floodway and the regulatory floodplain of the watercourse. “Erosion” means the process of the gradual wearing away of landmasses. This peril is not, per se, covered under the National Flood Insurance Program. “Erosion hazard area” means lands adjoining a watercourse that is regulated by this chapter which are deemed by the Town Engineer to be subject to flood-related erosion, pursuant to the Town’s adopted drainage criteria manual. “Erosion setback” means the minimum horizontal distance between a structure or permanent feature and the channel bank necessary to protect the structure/feature from flood-related erosion damage. For method to be used for determination of the erosion setback, see the adopted Town of Oro Valley drainage criteria manual. “Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are affixed (including, at a minimum, the installation of utilities, construction of streets, and either final site grading or the pouring of concrete slabs) was completed before December 4, 1979, the effective date of the Flood Insurance Rate Maps adopted by the Town of Oro Valley. “Expansion to an existing manufactured home park or subdivision” means preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads). “Federal Emergency Management Agency (FEMA)” means an agency of the Federal government responsible for programs of disaster response and recovery, disaster preparedness, hazard mitigation, flood insurance, and other programs of technical and financial assistance. “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) the overflow of floodwaters; (2) the unusual and rapid accumulation or runoff of surface waters from any source; and/or (3) the collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in this definition. “Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Emergency Management Agency has delineated both the special flood hazard areas and the risk premium zones applicable to the community. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 6 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Flood Insurance Study (FIS)” means the official report provided by Federal Emergency Management Agency that includes flood profiles, the Flood Insurance Rate Map, and the water surface elevation of the base flood. “Flood protection system” means those physical structural works for which funds have been authorized, appropriated, and expended; and which have been constructed specifically to modify flooding in order to reduce the extent of the area within a community subject to designation as a regulatory floodplain as well as the extent and depths of associated flooding. Such a system typically includes dams, reservoirs, levees or dikes. These specialized flood-modifying works are those constructed in conformance with sound engineering standards. “Floodplain” or “flood-prone area” means any land area susceptible to being inundated by water from any source (see “flood” or “flooding”). “Floodplain Administrator” means the Town Engineer, or their designee, whose duty it is to oversee administration and enforcement of the floodplain management regulations contained in this chapter. “Floodplain Board” means the Town Council of Oro Valley, at such times as they are engaged in the enforcement of this chapter. “Floodplain management” means the operation of an integrated natural resource management program encompassing corrective and preventive measures for reducing flood and erosion damage. Floodplain management includes but is not limited to emergency preparedness planning, flood control works, floodplain management regulations, and open space plans. “Floodplain management regulations” means this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control), and other applications of legal and regulatory authority that control use of, and development in, flood-prone areas. This term describes Federal, State, or local regulations, and any combination thereof, which provide standards for preventing and reducing flood loss and damage. “Floodplain use permit” (also “permit for development in a floodplain”) means an official document that authorizes special activity within regulatory floodplains or erosion hazard areas of Oro Valley. “Flood-proofed” or Dry Floodproofed means a building or structure that has been made watertight with walls substantially impermeable to the passage of water, and structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy, accomplished by means other than elevation. “Flood-proofing” means any combination of structural and nonstructural additions, changes, or adjustments to nonresidential structures that reduces or eliminates flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents by means other than elevation. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 7 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Flood-related erosion” means the collapse or subsidence of land along the shore of a lake or other body of water as a result of undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding. Floodway. See “regulatory floodway.” “Floodway fringe” means that area of the floodplain lying on either side of a regulatory floodway where encroachment may be permitted. “Functionally dependent use” means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long-term storage or related manufacturing facilities. “Governing body” is the local governing unit (i.e., county or municipality) empowered to adopt and implement regulations providing for the public health, safety, and general welfare of its citizenry. “Hardship” means that the physical characteristics of the property in question are so unusual, exceptional, and peculiar to the property that a variance regarding its use may be requested and granted in accordance with Section 17-6-1. Mere economic or financial hardship alone is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one’s neighbors likewise cannot, as a rule, be construed to qualify as an exceptional hardship. All of these problems can be resolved through other means without granting a variance, even if the alternative is more expensive, requires the property owner to build elsewhere, or means that the parcel must be put to a different use than originally intended. “Highest adjacent grade” means the highest natural elevation of the ground surface immediately adjacent to a structure prior to construction of the proposed walls of a structure. “Historic structure” means any structure that is: 1.  Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; 2.  Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; 3.  Individually listed on the State of Arizona inventory of historic places, as approved by the Secretary of the Interior; or Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 8 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 4.  Individually listed on the Town of Oro Valley’s inventory of historic places and that has been certified by an approved State of Arizona program, as determined by the Secretary of the Interior. “Landscape vegetation” means vegetation that is installed, planted, irrigated, maintained, or otherwise placed or modified by human activity. Naturally occurring native vegetation within the floodplain is not considered landscape vegetation. “Levee” means a human-made structure, usually an earthen embankment designed and constructed in accordance with sound engineering practices, for the purpose of containing, controlling, or diverting the flow of water so as to provide protection from temporary flooding. “Lowest floor” means the lowest floor of the lowest enclosed area including the basement (see “basement” definition) or crawl space under a manufactured home if it is not vented. An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered to be the lowest floor of a structure; provided, that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this chapter. “Manufactured home” means a structure, transportable in one (1) or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.” “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale. “Market value” means the determination of the estimated cost to replace the structure in new condition and adjusting that cost figure by the amount of depreciation that has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and functional obsolescence as approved by the Floodplain Administrator but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences. Alternatively, the market value is the valuation made by the Pima County Assessor’s Office. “Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum of 1988 (NAVD ’88), or other datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 9 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “National Flood Insurance Program (NFIP)” means a program administered by FEMA that makes Federally backed flood insurance available for purchase by individuals that live in NFIP participating communities. New Construction. For the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial Flood Insurance Rate Map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures. “Obstruction” includes, but is not limited to, any dam, wall, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, structure, wire, fence, rock, gravel, refuse, fill, structure, vegetation, or other material in, along, across, or projecting into any watercourse which may alter, impede, retard, or change the direction and/or velocity of the flow of water, or which due to its location influences its propensity to snare or collect debris carried by the flow of water, thereby reducing its likelihood of being carried downstream as well as reducing the channel’s ability to convey flow. “One hundred (100) year flood” means the flood having a one percent (1%) chance of being equaled or exceeded in any given year (see “base flood”). Also referred to as the one percent (1%) annual exceedance probability flood (one percent (1%) AEP flood). “Permit for development in a floodplain” (also referred to as a “floodplain use permit”) is an official document issued by the Town of Oro Valley authorizing performance of specific activity in any regulatory floodplain or erosion hazard area after it has been determined to be reasonably safe from flooding and erosion. These permits are required to ensure that proposed development projects meet the requirements of the NFIP and the provisions of this chapter. Examples include grading permits, building permits, and floodplain use permits. “Person” means an individual, firm, partnership, association or corporation, or agent of the aforementioned groups, or the State of Arizona or its agencies or political subdivisions. “Program” means the National Flood Insurance Program authorized by 42 U.S.C. 4001 through 4128, or as authorized by subsequent Federal statutes. “Reach” is a hydraulic engineering term to describe longitudinal segments of a stream or watercourse. A reach will generally include the segment of the flood hazard area where flood heights are primarily controlled by manmade or natural obstructions or constrictions. In an urban area, an example of a reach would be the segment of a stream or watercourse between two (2) consecutive bridge crossings. “Recreational vehicle” means a vehicle that is: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 10 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Built on a single chassis; 2.  Four hundred (400) square feet or less in area, when measured at the largest horizontal projection; 3.  Designed to be self-propelled or permanently towable by a light duty truck; and 4.  Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. “Regulatory flood elevation” means the base flood elevation plus one (1) foot of freeboard as required by this chapter. “Regulatory floodplain or flood-prone area” means that portion of the geologic floodplain associated with a watercourse, including its channel, or any other floodplain or flood-prone area that would be inundated by the base flood, including all base floods where the base flood peak discharge is one hundred (100) cubic feet per second or greater, those areas that are subject to sheet flooding except when the maximum potential contributing watershed area is less than twenty (20) acres, those areas identified on subdivision plats or development plans, those areas designated by FEMA, including areas designated as shaded Zone X as well as those areas that the Floodplain Administrator, using the best available data, has determined is subject to a flood hazard during the base flood. “Regulatory floodway” means the channel of a watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated amount. “Remedy a violation” means to bring the structure or other development into compliance with State or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of this chapter, otherwise deterring future similar violations, or reducing Federal financial exposure with regard to the structure or other development. “Repetitive loss structure” means a structure, covered by a contract for flood insurance issued pursuant to the National Flood Insurance Act, that has incurred flood-related damage on two (2) occasions during any ten (10) year period ending on the date of the event for which a second claim is made, and for which the cost of repairing the flood damage, on average, equaled or exceeded twenty-five percent (25%) of the market value of the structure at the time of each such flood event. In addition to the current claim, the NFIP must have paid the previous qualifying claim. “Retention system” means a type of flood control system that stops the downstream progress of floodwater by employing methods of total containment which generally involve creation of storage areas that incorporate infiltration devices, such as dry wells, to dispose of stored waters, principally Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 11 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. by percolation over some specified period of time, thereby eliminating basin contributions to downstream flood peaks or flood volumes. “Riverine” means relating to, formed by, or resembling a river (including tributaries), stream, brook, etc. Sheet Flow Area. See “area of shallow flooding.” “Special flood hazard area (SFHA)” means an area in the regulatory floodplain subject to a one percent (1%) or greater chance of flooding in any given year. SFHAs are shown on a Flood Insurance Rate Map as Zone A, AO, AE, AH or A0. “Start of construction” includes substantial improvement or other proposed new development, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within the time period when the permit was active. The “actual start” means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation such as the installation of streets and/or walkways, the installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the “actual start of construction” means the first alteration of any wall, ceiling, floor or other structural part of a structure, whether or not that alteration affects the external dimensions of the structure. “Storage” Contents stored in wet floodproofed structures will get wet during flooding. “Structure” means a walled and roofed building, including gas or liquid storage tanks, principally above ground and affixed to a permanent site. This term also refers to a manufactured home on a permanent foundation. “Structure Size” The footprint of a typical two-car garage is about 600 square feet in area. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred. “Substantial improvement” means any reconstruction, rehabilitation, addition, or other improvement to a structure, the total cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 12 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local Code Enforcement Official and which are the minimum necessary to assure safe living conditions; or 2.  Any alteration of a “historic structure”; provided, that the alteration will not preclude the structure’s continued designation as a “historic structure.” “Variance” means a grant of relief from the requirements of this chapter that is granted by the Floodplain Administrator or the Floodplain Board (for FEMA floodplains) upon a finding that strict enforcement of the provisions would cause undue hardship owing to circumstances unique to the individual property for which the variance is granted, and not caused by the applicant for said variance. “Violation” means the failure of a structure or other development to be fully compliant with the Town of Oro Valley floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required by this chapter is presumed to be in violation until such time as such documentation is provided. “Violation” also means unauthorized construction, grading, encroachment, diversion, or lack of maintenance of private drainage structures. “Water surface elevation” means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929 or the North American Vertical Datum (NAVD) of 1988 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of riverine and sheet- flow areas. “Watercourse” means a lake, river, creek, stream, wash, arroyo, channel, or other topographic feature on or over which waters flow at least periodically. “Watercourse” includes specifically designated areas in which substantial flood damage may occur, including regulatory floodplains as designated by FEMA or the Town of Oro Valley. “Zone A (unnumbered)” is a special flood hazard area identified by FEMA that is subject to inundation from a one hundred (100) year flood event. Because detailed hydraulic analyses have not been performed, no base flood elevation or depths are shown. Mandatory flood insurance requirements apply. “Zone AE” is a special flood hazard areas subject to inundation by the one hundred (100) year flood determined by a Flood Insurance Study (FIS). Base flood elevations are shown within these zones and mandatory flood insurance requirements apply. “Zone AH” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding (usually areas of ponding) with average depths between one (1) and three (3) feet. Base flood elevations derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance requirements apply. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 13 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Zone AO” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding, usually resulting from sheet flow on sloping terrain, with average depths between one (1) and three (3) feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. Mandatory flood insurance requirements apply. “Zone X shaded” (or “shaded Zone X”) is an area determined by a Flood Insurance Study as having moderate or minimal hazard from flooding. There are four classifications depending on location: (1) area of one hundred (100) year flood with average depths of less than one (1) foot; (2) area with drainage areas less than one (1) square mile; (3) area protected by an accredited levee from one hundred (100) year flood; and (4) area of five hundred (500) year flood. Buildings or other improvements in this zone could be flooded by severe, concentrated rainfall, in the absence of adequate drainage systems. Flood insurance is available in participating communities, but it is not required. In the Town of Oro Valley only the third classification applies (i.e., protected by levees). ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-3 GENERAL PROVISIONS Sections: 17-3-1 Lands to Which This Chapter Applies 17-3-2 Basis for Establishing the Regulatory Floodplain Areas 17-3-3 Compliance 17-3-4 Abrogation and Greater Restrictions 17-3-5 Interpretation 17-3-6 Statutory Exceptions 17-3-7 Floodplain Violations 17-3-8 Abatement of Violations 17-3-9 Unlawful Acts 17-3-10 Remedies 17-3-11 Severability 17-3-12 Warning and Disclaimer of Liability 17-3-1 Lands to Which This Chapter Applies. This chapter shall apply to all regulatory floodplain areas within the corporate limits of the Town of Oro Valley, including special flood hazard areas, floodplains shown on recorded subdivision plat maps, as well as those areas identified by the Floodplain Administrator, using the best available data. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 14 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-3-2 Basis for Establishing the Regulatory Floodplain Areas. The special flood hazard areas identified by the Federal Emergency Management Agency (FEMA) in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for Pima County, Arizona and Incorporated Areas,” revised September 28, 2012, with accompanying Flood Insurance Rate Maps (FIRMs) dated June 16, 2011, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This Flood Insurance Study (FIS) and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the Floodplain Board by the Floodplain Administrator. The Floodplain Board, within the incorporated limits of the Town of Oro Valley, shall require developers of land to delineate, within areas where development is ongoing or imminent, floodplains consistent with the criteria developed by FEMA, the Arizona Director of Water Resources, and the Town Engineer, pursuant to the Town’s adopted drainage criteria manual. The Flood Insurance Study FIS and FIRMs are on file at the Town of Oro Valley Public Works Department. A.  Regulatory floodplains shall be subject to requirements in Section 17-5-8 (Floodway Fringe Area Requirements). B.  Elevation and Boundary Refinements. 1.  The determination of elevations (water surface, lowest finished floor, and adjacent land) and regulatory floodway and regulatory floodplain boundaries is an engineering function with calculations and decisions made in accordance with the concepts and policies set forth in this chapter. The best technical data available shall be used for such calculations and decisions. Initial determinations shall be based on floodplain information reports of the Pima County Flood Control District, U.S. Corps of Engineers, U.S. Bureau of Reclamation, U.S. Geological Survey, and/or other general data that are pertinent for the conditions of the streams or the watercourses at the time the data are obtained. 2.  Additional and more detailed technical analysis will, from time to time, become available through private or governmental studies and activities. This data will permit refinements in the elevations and boundaries of the regulatory floodway and regulatory floodplains in the respective reaches of the streams or watercourses. 3.  Whenever such additional data become available and it seems desirable to make refinements, i.e., letter of map amendments (LOMAs) or letter of map revisions (LOMRs), such refinements or revisions may be made at the request of the property owners or developers or by the Town Engineer. The necessary engineering calculations shall be made for the property owner or developer by an Arizona registered professional engineer (at the owner’s/developer’s expense) in conformance with requirements of this chapter, the FEMA, and the Arizona Department of Water Resources (ADWR). These findings will need approval of the Town Engineer. Following the Town’s approval of these refinements to regulatory floodplain areas Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 15 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. identified on FIRMs, the property owner shall have calculations and forms forwarded to FEMA for review and approval. 4.  The Town Engineer or their duly designated representative shall have the authority and responsibility to revise and refine elevations and boundaries of regulatory floodways and regulatory floodplains whenever such revisions and refinements are for the purpose and in accordance with the conditions set forth in Sections 17-4-3(B)(1)(d), 17-5-8(B)(3), (4), and (5). a.  The Flood Insurance Rate Map for Pima County and incorporated areas shall be revised to show the refined area boundaries and/or elevations. b.  The Town Engineer shall notify the owner of each property for which area boundaries and/or elevations have been revised or refined, as well as those owners of adjoining property immediately upstream and downstream, by first class mail following a duly noticed public hearing on the property involved. c.  An appeal to the Floodplain Board may be taken by any person aggrieved, in accordance with Article 17-6. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-3 Compliance. All development of land, construction of residential, commercial, or industrial structures, or future development within regulatory floodplain areas is subject to the terms of this chapter and any other applicable regulations. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-4 Abrogation and Greater Restrictions. The provisions of this chapter are not intended to interfere with, abrogate, or annul any ordinance, rule, regulations, or permit previously adopted or issued, and not be in conflict with any provision of this chapter or any regulation that shall be adopted or issued pursuant to law relating to the use of structure or ordinance not in conflict with this chapter; nor is it intended by this chapter to interfere with or abrogate or annul any easement, covenant, or other agreement between parties, except when this chapter imposes a greater restriction, this chapter shall control. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-5 Interpretation. In the interpretation and application of this chapter, all provisions shall be: A.  Considered as minimum requirements; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 16 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. B.  Liberally constructed in favor of the governing body; and C.  Deemed neither to limit nor repeal any other powers granted under State statutes. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-6 Statutory Exceptions. A.  In accordance with ARS § 48-3609(I), unless expressly provided this and any regulations adopted pursuant to this article do not affect: 1.  Existing legal uses of property or the right to continuation of such legal use. However, if a nonconforming use of land or a structure is discontinued for twelve (12) months or destroyed to the extent of fifty percent (50%) or more of its market value, as determined by a competent appraiser, or the valuation made by the Pima County Assessor’s Office, any further use shall comply with this article and regulations of the Town of Oro Valley. 2.  Reasonable repair or alteration of property for the purposes for which the property was legally used on August 3, 1984, or any regulations affecting such property takes effect, except that any alteration, addition, or repair to a nonconforming structure which would result in increasing its flood damage potential by fifty percent (50%) or more shall be either flood-proofed or elevated to or above the regulatory flood elevation. 3.  Reasonable repair of structures constructed with the written authorization required by ARS § 48-3613. 4.  Facilities constructed or installed pursuant to a certificate of environmental compatibility issued pursuant to ARS Title 40, Chapter 2, Article 6.2. B.  Before the following types of construction authorized by ARS § 48-3613(B) may begin, the responsible person must submit grading plans and a grading permit application for review and comment. Written authorization is not required for, nor shall the floodplain board prohibit, the following pursuant to ARS § 48-3613(C): 1.  The construction of bridges, culverts, dikes, and other structures necessary for the construction of public highways, roads, and streets intersecting or crossing a watercourse. 2.  The construction of storage dams for watering livestock or wildlife, structures on banks of a watercourse to prevent erosion of, or damage to, adjoining land, if the structure will not divert, retard or obstruct the natural channel of the watercourse, or dams for the conservation of floodwaters as permitted by ARS Title 45, Chapter 6. 3.  The construction of tailing dams and waste disposal areas for use in connection with mining and metallurgical operations. This subsection does not exempt those sand and gravel Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 17 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. operations that will divert, retard or obstruct the flow of waters in any watercourse from complying with, and acquiring authorization from, the Town Engineer or the Floodplain Board pursuant to regulations adopted by the Floodplain Board under this article. 4.  Other construction, if it is determined by the Town Engineer that a floodplain use permit is unnecessary. 5.  Any flood control district, county, city, town, or other political subdivision from exercising powers granted to it under ARS Title 48, Chapter 21, Article 1. 6.  The construction, by a public agency or political subdivision, of streams, waterways, lakes, and other auxiliary facilities in conjunction with development of public parks and recreation facilities. 7.  The construction and erection of poles, towers, foundations, support structures, guy wires, and other facilities related to power transmission as constructed by any utility, whether a public service corporation or a political subdivision. C.  In accordance with ARS § 48-3613(D), in addition to other penalties or remedies otherwise provided by law, the State of Arizona, a political subdivision thereof, or a person who may be damaged or has been damaged as a result of the unauthorized diversion, retardation, or obstruction of a watercourse has the right to go through an administrator/board to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate this section or regulations adopted pursuant to ARS Title 48, Chapter 21, Article 1. If a person is found to be in violation of this section, the administrator/board shall require the violator either to comply with this section, if authorized by the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), or to remove the obstruction and restore the watercourse to its original state. The court may also award such monetary damages as are appropriate to the injured parties resulting from the violation, including reasonable costs and attorney fees. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-7 Floodplain Violations. A.  Declaration of Public Nuisance. All development located or maintained within any regulatory floodplain area after August 8, 1973, in violation of this chapter, and without written authorization from the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), is a public nuisance per se, and may be abated, prevented or restrained by action of the Floodplain Board. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 18 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-3-8 Abatement of Violations. Upon discovery of a violation to this chapter, the Floodplain Administrator shall either: A.  Take any necessary action to effect the abatement of such violation; or B.  Order the owner of the property upon which the violation exists to provide whatever additional information may be required for determination by the Floodplain Administrator. Such information must be provided to the Floodplain Administrator within thirty (30) days of such order. Within thirty (30) days, the Floodplain Administrator shall either order the abatement of said violation or shall grant a variance in accordance with the provisions of Section 17-6-4; or C.  For FEMA regulated floodplains (SFHAs), submit to the Federal Emergency Management Agency a declaration for denial of insurance, stating that the property is in violation of a cited State or local law, regulation or ordinance, pursuant to Section 1316 of the National Flood Insurance Act of 1968, and as amended. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-9 Unlawful Acts. A.  It is unlawful for a person to engage in any development or to divert, retard, or obstruct the flow of waters in a watercourse if it creates a hazard to life or property without securing the written authorization required by ARS § 48-3613. Where the watercourse is a delineated floodplain, it is unlawful to engage in any development affecting the flow of waters without securing written authorization required by ARS § 48-3613. B.  When drainage improvements are associated with an approved development plan, subdivision plat or approved engineering report, and are constructed to provide flood protection to remove or reduce flood hazards, including those identified by FEMA or for stormwater quality control, and where those improvements are privately owned, then it shall be the responsibility of the property owner(s) to perform maintenance as necessary to ensure the integrity of said drainage improvements and maintenance of the flood carrying capacity to the designed discharge. For purposes of this chapter, a private drainage improvement is considered a structure. It is unlawful for any person or entity to neglect maintenance responsibilities on private drainage improvements. C.  Any person violating the provisions of this section shall be subject to appeal and variance procedures pursuant to Article 17-6, and penalties pursuant to Article 1-8, Penalties. D.  The Town may issue a written notice to correct to any person who has violated or is in violation of this section. E.  Failure to comply with actions described in and required by the notice to correct may result in a notice of violation and/or stop work order. The written notice shall state the nature of the violation, Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 19 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. the corrective action required, the time frame for the corrective action, and penalties for continued noncompliance. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-10 Remedies. All remedies provided for herein shall be cumulative and not exclusive. The conviction and punishment of any person hereunder shall not relieve such person from the responsibility to correct prohibited conditions or to remove prohibited structures, obstructions, or improvements; nor prevent the enforcement, correction, or removal thereof. In addition to the other penalties or remedies provided in this article, the State of Arizona, any political subdivision thereof, or any person who may be damaged as a result of the diversion, retardation, or obstruction of a watercourse shall have the right to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate any provision of this chapter. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-11 Severability. This chapter, and its various parts thereof, is hereby declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any portion thereof, other than the section so declared to be unconstitutional or invalid. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-12 Warning and Disclaimer of Liability. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes, and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the regulatory floodplain areas or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the Town of Oro Valley, any officer or employee thereof, the State of Arizona, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05- 35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 20 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. Article 17-4 ADMINISTRATION Sections: 17-4-1 Establishment of Floodplain Use Permits 17-4-2 Enforcement and Inspection 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures 17-4-4 Designation of the Floodplain Administrator 17-4-1 Establishment of Floodplain Use Permits. A.  Responsibility for Permits. It shall be the duty of the Town Engineer acting as the Floodplain Administrator, and all departments, officials, and public employees vested with the duty or authority to issue permits or licenses, to enforce the provisions of this chapter; and no such license or permit shall be issued for uses or buildings where the same would be in conflict with the provisions of this chapter. Any such license or permit, if issued in conflict with the provisions of this chapter, shall be null and void. B.  Floodplain Use Permits. It shall be unlawful to erect, construct, reconstruct, alter, or change the use of any structure within any regulatory floodplain area covered by this chapter without first applying for and obtaining a floodplain use permit from the Town Engineer. C.  Application for Floodplain Use Permit. Application for a floodplain use permit shall be made on forms furnished by the Town Engineer, and must include, without limitation, plans in duplicate drawn to scale showing the nature, location, dimensions, and elevation of the areas in question; existing or proposed structures including walls, bank protection, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required: 1. Proposed elevation, in relation to mean sea level, of the lowest floor (including basement) of all structures. In a designated Zone AO, elevation of existing highest adjacent natural grade and proposed elevation of the lowest floor (including basement) of all structures must be obtained; 2.  Proposed elevation, in relation to mean sea level, to which any nonresidential structure will be flood-proofed; 3.  Certification by an Arizona registered professional engineer or an Arizona registered professional architect that the flood-proofing methods for any nonresidential structure meet the flood-proofing criteria in Section 17-5-1(C); 4.  Base flood elevation data shall be provided for subdivisions or other developments greater than fifty (50) lots or five (5) acres, whichever is the lesser; and Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 21 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 5.  Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. Each such application shall be accompanied by an application fee, as set forth by the Town, payable to the Town of Oro Valley. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-4-2 Enforcement and Inspection. A.  Enforcement. It shall be the duty of the Floodplain Administrator and officials of the Town otherwise charged with the enforcement of the law, to enforce this chapter and all of the provisions of the same. B.  Inspections. Inspections shall be made by officials of the Town duly appointed by the Town Engineer or by a duly appointed Floodplain Administrator. C.  Cooperation. The Town Floodplain Administrator may request, and shall receive so far as may be necessary in the discharge of their duties, the assistance and cooperation of all departments, agencies, officials, and public employees vested with the duty or authority to issue permits, licenses, or to enforce the regulations of this chapter. D.  Town of Oro Valley Administration. Hydrologic, hydraulic, and related floodplain regulations, as well as engineering matters pertaining to the administration and direction of this chapter, shall be referred to the Town of Oro Valley Town Engineer or their designated representative, who shall be responsible for such reviews, advice, and recommendations. E.  Cooperation Agreements and Consultants. The Floodplain Administrator, through the applicable procurement and/or intergovernmental agreement procedures, may retain consultants and experts; and may enter into cooperative agreements for the delineation of floodplains and floodways as well as for such other assistance and guidance considered appropriate and necessary to obtain maximum reasonable protection and benefits under this chapter. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures. A.  The Floodplain Administrator shall issue floodplain use permits required by this section. B.  The following procedure shall be used by the Floodplain Administrator in considering issuance of floodplain use permits: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 22 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Upon receiving an application for a floodplain use permit involving the use of fill, construction of structures, or the storage of materials, and prior to rendering a decision thereon the Floodplain Administrator may: a.  Require the applicant to submit, where applicable, plans in triplicate drawn to scale showing the nature, location, dimensions, and elevations of the lot; existing or proposed structures, fill, storage of materials, flood-proofing measures; and the relationship of the above to the location of the channel, regulatory floodway, regulatory floodplain, the regulatory floodplain with base flood elevations, the proposed project in relation to flood heights and velocities, and the plans for flood protection. The applicant shall provide a new delineation of all regulatory floodplains affected by the project. The new delineation and reports shall be prepared in conformance with FEMA requirements and this chapter. The delineation shall show pre- and post-project floodplain limits and water surface elevations upstream, adjacent, and downstream of the project. b.  Require, where circumstances necessitate more detailed information, the applicant to furnish as much of the following additional information as is deemed necessary by the Floodplain Administrator for the evaluation of the effects of the proposed use upon flood flows and the consideration of other factors necessary to render a decision on suitability of the proposed use: i.  A typical valley cross-section showing the floodway, floodway fringe area, and the floodplain of the watercourse; elevation of land areas adjoining each side of the channel; cross-sectional areas to be occupied by the proposed development; and high water information; ii.  A plan (surface view) showing elevations or contours of the ground; pertinent structure, fill or storage elevations; size, location, and spatial arrangement of all proposed and existing structures on the site; location and elevations of streets, water supply, sanitary facilities; photographs showing existing land uses and vegetation upstream and downstream, and soil types, as well as other pertinent information; iii.  A profile showing the slope of the bottom of the channel or flow line of the watercourse; iv.  Specifications for building construction and materials, flood-proofing, filling, dredging, grading, channel improvement, storage of materials, water supply, and sanitary facilities. c.  Ensure that the proposed development does not adversely affect the carrying capacity of channels at locations where base flood elevations have been determined but a floodway has not been designated. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 23 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. d.  For FEMA regulated floodplains (SFHAs), require the applicant to submit appropriate (e.g., CLOMR, CLOMR-F, LOMR, etc.) applications, forms, and information to FEMA for review and approval. A floodplain use permit shall not be issued by the Town of Oro Valley until after receiving acknowledgement from FEMA of the acceptance of the CLOMR. Additionally, final building permit inspections shall not be made, nor shall certificates of occupancy be given, until after receiving acknowledgement from FEMA that the LOMR has become effective. e.  Ensure other related State of Arizona and Federal permits have been issued. 2.  No permit shall be issued for any development that is not in conformance with this chapter, FEMA regulations, or some other provision of law relating to such development. A floodplain use permit may be denied if the proposed development constitutes a danger or hazard to life or property. C.  The Floodplain Administrator shall be responsible for the following duties: 1.  Obtain and maintain for public inspection and make available the following: a.  Certification of the regulatory flood elevation required in Sections 17-5-1(C)(1), 17-5- 1(C)(2), and 17-5-5; b.  The Zone AO certification required in Section 17-5-1(C)(2); c.  The flood-proofing certification required in Section 17-5-1(C)(3); d.  The certified opening elevation required in Section 17-5-1(C)(4); e.  Review all development permits for improvements and/or damages to existing structures to determine if the application of the substantial improvement rules apply, including establishing a definition of market value determination and verifying that the estimated improvement and/or repair costs are less than fifty percent (50%) of the market value of the structure; f.  Certification of elevation for subdivisions required by Section 17-5-4(E); g.  Certification for floodway encroachments required by Section 17-5-7(A); h.  Records of all variance actions, including justification for their issuance required by Section 17-6-3(C). 2.  Notification of other entities: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 24 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. a.  Notify adjacent communities and ADWR prior to such alteration or relocation of a watercourse, and submit evidence of such notification to FEMA through appropriate notification means; and b.  Require that the flood carrying capacity of the altered or relocated portion of said watercourse be maintained. 3.  Within one hundred twenty (120) days after completion of construction of any flood control protective works which change the rate of flow during the flood or the configuration of the floodplain upstream or downstream from or adjacent to the project, the person or agency responsible for installation of the project shall provide to the governing bodies of all jurisdictions affected by the project a new delineation of all floodplains affected by the project. The new delineation shall be done according to the criteria adopted by the ADWR. 4.  Advise the Pima County Regional Flood Control District and any adjunct jurisdiction having responsibility for floodplain management in writing and provide a copy of a development plan of all applications for floodplain use permits or variances to develop land in a floodplain or floodway within one (1) mile of the corporate limits of the Town of Oro Valley, Arizona. Also, advise the Pima County Regional Flood Control District in writing and provide a copy of any development plan of any major development proposed within a floodplain or floodway, which could affect floodplains, floodways or watercourses within the district’s area of jurisdiction. Written notice and a copy of the plan of development shall be sent to the district no later than three (3) working days after having been received by Town of Oro Valley. 5.  Notify FEMA of acquisition by means of annexation, incorporation or otherwise, of additional areas of jurisdiction. 6.  A community’s base flood elevations may increase or decrease resulting from physical changes affecting flooding conditions. As soon as practicable, but not later than six (6) months after the date such information becomes available, a community shall notify FEMA of the changes by submitting technical or scientific data in accordance with 44 CFR 65.3. Such a submission is necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements will be based upon current data. 7.  Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 17-3-2 (Basis for Establishing the Regulatory Floodplain Areas), the Floodplain Administrator shall obtain, review and reasonably utilize any base flood elevation data available from a Federal, State, or other source, in order to administer Section 17-5-1 (Standards of Construction). Any such information shall be consistent with the requirements of the Federal Emergency Management Agency and the Director of the Arizona Department of Water Resources and may be submitted to the Floodplain Board for adoption. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 25 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 8.  Make map interpretations, where needed, as to the exact location of the boundaries of the special flood hazard areas (e.g., where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Article 17-6 (Appeal and Variance Procedures). 9.  Take remedial actions on violations of this chapter as required in Section 17-3-8 (Abatement of Violations). ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-4-4 Designation of the Floodplain Administrator. The Town Engineer or their designee is hereby appointed to administer, implement, and enforce this chapter and guidelines set forth in this article by processing floodplain use permits in accordance with its provisions. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-5 PROVISIONS FOR FLOOD HAZARD REDUCTION Sections: 17-5-1 Standards of Construction 17-5-2 Standards for Storage of Materials and Equipment 17-5-3 Standards for Water Supply and Waste Disposal Systems 17-5-4 Standards and Submittal Requirements for Subdivisions 17-5-5 Standards for Manufactured Homes 17-5-6 Standards for Recreational Vehicles 17-5-7 Floodways 17-5-8 Floodway Fringe Area Requirements 17-5-9 Flood-Related Erosion-Prone Area 17-5-1 Standards of Construction. In all regulatory floodplain areas, the following standards are required: A.  Anchoring. 1.  All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 26 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 2.  All manufactured homes shall meet the anchoring standards of Section 17-5-5(B). B.  Construction Materials and Methods. 1.  All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. 2.  All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. 3.  All new construction, substantial improvements, and other proposed new development shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment, as well as other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding. 4.  Within Zone AH or AO, adequate drainage paths around structures on slopes are required to guide floodwaters around and away from proposed structures. C.  Elevation and Flood-Proofing. 1.  New construction and substantial improvement of any structure shall have the lowest floor, including basement, elevated at or above the regulatory flood elevation. In areas without a detailed study but within regulatory floodplain boundaries, the applicant shall have an Arizona registered professional engineer prepare a detailed study to determine the depth of the base flood. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure, the elevation of the lowest floor, including basement, shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor, and provided to the Floodplain Administrator and the Town Building Official. 2.  New construction and substantial improvement of any structure in Zone AO shall have the lowest floor, including basement, higher than the highest adjacent grade at least one (1) foot higher than the depth number on the FIRM, or at least two (2) feet if no depth number is specified. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon completion of the structure an Arizona registered professional engineer or Arizona registered professional land surveyor shall certify to the Floodplain Administrator that the elevation of the structure meets this standard. 3.  Nonresidential construction and new and substantial improvement of any structure shall either be elevated in conformance with subsections (C)(1) and (2) of this section, or together with attendant utility and sanitary facilities: a.  Be flood-proofed so that below the regulatory flood elevation the structure is watertight with walls substantially impermeable to the passage of water; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 27 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. b.  Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and c.  Be certified by an Arizona registered professional engineer or an Arizona registered professional architect that the standards of this subsection are satisfied. Such certifications shall be provided to the Floodplain Administrator and the Town Building Official. 4.  Require, for all new construction and substantial improvements of nonresidential structures, that have fully enclosed areas below the regulatory flood elevation that are usable solely for parking of vehicles, building access, or storage in an area other than a basement, and which are subject to flooding, shall be constructed of flood resistant materials to the regulatory flood elevation, have all service facilities elevated at or above the regulatory flood elevation, and be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by an Arizona registered professional engineer or an Arizona registered professional architect or meet or exceed the following minimum criteria: a.  A minimum of two (2) openings, on different sides of each enclosed area, shall be provided having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. Smaller engineered openings may be allowed if the design is supported by a certification report issued by ICC-ES (International Code Council Evaluation Service), or an equivalent product certification organization. b.  The bottom of all openings shall be no higher than one (1) foot above grade. c.  Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters. 5.  Manufactured homes shall meet the standards in Section 17-5-5. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-2 Standards for Storage of Materials and Equipment. A.  The storage or processing of materials is prohibited if they are, in time of flooding: buoyant, flammable, explosive, or could be noxious, deadly, or injurious to human, animal, or plant life. B.  Storage of other material or equipment may be allowed if they are not subject to major damage by floods, or if they are firmly anchored to prevent flotation, or if they are readily removable from the area within the time available after flood warning. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 28 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-5-3 Standards for Water Supply and Waste Disposal Systems. A.  All new or replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from systems into floodwaters. B. On-site waste disposal systems shall not be installed wholly or partially in a regulatory floodway, erosion setback, or as established by the Arizona Department of Environmental Quality (ADEQ), whichever is most restrictive. C.  On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-4 Standards and Submittal Requirements for Subdivisions. A.  All new subdivision proposals and other proposed development (including proposals for manufactured home parks and subdivisions), greater than fifty (50) lots or five (5) acres, whichever is the lesser, shall: 1.  Identify the regulatory floodplain area and the elevation of the base flood; and 2.  Identify on the final plans the elevation(s) of the proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and grade elevations shall be certified by an Arizona registered professional engineer or Arizona registered professional land surveyor and provided to the Floodplain Administrator. B.  All subdivision proposals shall be consistent with the need to minimize flood damage. C.  All subdivision proposals (also referred to as a final site plan) shall have all public utilities and facilities, including but not limited to sewer, gas, electrical, and water systems, located and constructed to minimize flood damage. D.  All subdivisions shall provide adequate drainage to reduce exposure to flood hazards (see adopted drainage criteria manual). E.  Suitability of the Land. Land that has been found by the Floodplain Board to be unsuitable for development with permanent structures based on hydrological and engineering studies of flooding can be platted and used only for open space and greenbelt uses such as those identified in Section 17-5-7(B)(1). This includes land which is: 1.  Physically unsuitable because of flooding, poor drainage, and other features which may endanger health, life, or property, aggravate erosion, increase the flood hazard, or increase the burden imposed on the community, its governmental units, and its citizens; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 29 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 2.  Subject to flooding because of its proximity to the stream or watercourse; or because of low elevation. In applying this provision, the Floodplain Board, with technical support and recommendations from the Town Engineer, shall consider: a.  Land subject to flooding by the base flood shall not be platted for residential occupancy, or building sites, or for any other uses that may increase the flood hazard or endanger health, life, or property, unless each lot contains a building site that meets requirements set forth below, in subsections (G) and (H) of this section, and within other pertinent sections of this chapter; b.  Fill shall not be used to raise land within the regulatory floodway. In other areas subject to flooding by the base flood, fill may be used; provided, that the proposed fill does not restrict the flow of water and increase flood heights or velocities in the regulatory floodway, according to the same standards established in Section 17-5-8; and provided, that compensatory flood storage is provided. F.  Flood Situation to Be Shown on Plat. Plats submitted shall show the following: 1.  Conceptual site development plans (plats) shall show the location, by survey, of watercourses, channels, irrigation laterals, private ditches, culverts, lakes, or other water features, including direction of flow, water level elevations, and the location and extent of areas subject to frequent inundation; 2.  All preliminary subdivision proposals shall identify the special flood hazard areas, regulatory floodplain, the elevation of the base flood, pre- and post-development water surface elevations, and pre- and post-development floodplain limits; 3.  All conceptual and final subdivision plans will provide the elevation(s) of proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and pad elevation shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor and provided to the Floodplain Administrator and the Town Building Official; 4.  Final plats shall show the limits of the regulatory floodplain and the regulatory floodway, as well as the corresponding one hundred (100) year flood peaks, and their contributing drainage areas, entering and exiting the development; 5.  Conceptual and final site plans shall show proposed improvements for areas subject to flooding and/or for areas which contain extremely poor drainage facilities such that the proposed improvements make the areas safe from flooding for the respective type of occupancy. G.  Street Elevations. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 30 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Refer to the Town’s adopted drainage criteria manual and subdivision street standards for additional information and requirements. 2.  Fill used for the streets in areas subject to flooding shall not increase flood heights more than a designated amount as defined in Section 17-5-8(A)(1)(b). 3.  The developer shall provide pre- and post-developed water surface elevation for streets proposed for placement in or adjacent to areas subject to flooding. Headwater ponding limits and water surface elevations shall be shown upstream of all culvert crossings. H.  Building Site. 1.  Residential lots shall contain a building site, either natural or manmade, which is not subject to flooding by the base flood. 2.  In areas subject to flooding by the base flood, where no fill is proposed, the building line shall be located no closer to the watercourse or channel than the edge of the area subject to flooding by the base flood. In areas where fill is used to raise the elevation of the building site, no fill shall be placed in the regulatory floodway. Further, where fill is used, the erosion setback shall not be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for protected banks. I.  Setback from Channels. Along reaches of all regulated watercourses, erosion setback requirements from banks of washes shall be established in accordance with the Town’s adopted drainage criteria manual or standards accepted by the Town Engineer. J.  Easements for Drainage. Whenever any watercourse is located in the area being subdivided, an easement or common area encompassing each side of the watercourse shall be provided for the purpose of protecting and/or maintaining the watercourse for flood and drainage purposes, and such further width for construction of bank protection, physical access for maintenance, or for allowing for natural meander of the stream or watercourse that may be reasonably expected, or for all these as will be adequate for the purpose, as determined by the Town Engineer. K.  Detention/Retention Systems. See Town’s adopted drainage criteria manual for requirements pertaining to detention/retention systems by visiting the administrative offices of the Town of Oro Valley. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-5 Standards for Manufactured Homes. All manufactured homes that are placed within or substantially improved while located within a regulatory floodplain shall apply for and obtain a floodplain use permit summarizing site conditions including base flood elevation, depth of the base flood, and minimum prudent erosion setback. The application for a floodplain use permit shall be accompanied by a site plan, prepared by an Arizona Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 31 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. registered engineer, that conforms to the State of Arizona Office of Manufactured Housing, “Minimum Standards for Manufactured Housing Foundations in Floodplains,” dated October 14, 2009, or as subsequently amended. Accessory structures attached to a manufactured home must meet the provisions of this chapter unless its uses are limited to parking of vehicles or storage. Furthermore, manufactured homes shall: A. Be elevated so that the lowest structural member or the lowest point of any attached appliances, whichever is lower, is at or above the regulatory flood elevation. B.  Be securely anchored to an adequately anchored foundation system to resist flotation, collapse, or lateral movement. This anchoring requirement is in addition to applicable State and local anchoring requirements for resisting wind forces; and C.  Upon completion of installation of the manufactured home, certification by an Arizona registered professional engineer or Arizona registered professional land surveyor that the elevation requirements of this section have been satisfied shall be provided to the Floodplain Administrator for verification. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-6 Standards for Recreational Vehicles. All recreational vehicles placed within a regulatory floodplain area will either: A.  Be on site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use, to the extent that they are not prohibited by any other ordinance. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions; or B.  Meet the permit requirements of Article 17-4, and the elevation and anchoring requirements for manufactured homes in Section 17-5-5. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-7 Floodways. Located within regulatory floodplain areas, established in Section 17-3-2, are areas designated as regulatory floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris, potential projectiles, and increase erosion potential, the following provisions apply: A.  Encroachments, including fill, new construction, substantial improvements, and other development are prohibited in floodways. The Floodplain Administrator will consider encroachments where certification by an Arizona registered professional engineer is provided demonstrating that Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 32 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. encroachments will result in no increase whatsoever in flood levels during the occurrence of the base flood discharge, and that the encroachment will not pose a threat to life or property. B.  Floodway Requirements. 1.  Uses Permitted. The following open space uses shall be permitted to the extent that they are not prohibited by any other ordinance or State or Federal permit requirements, nor conflict with uses permitted in adjoining zones, and provided they do not require structures, fill, or storage of materials or equipment: a.  Agricultural uses, including general farming, pasture, grazing or outdoor plant nurseries, horticulture, viticulture, truck farming, sod farming, wild crop harvesting, and restoration of native vegetation; b.  Private and public recreational uses; c.  Accessory residential uses, including lawns, gardens, and play areas. C.  Limitations. 1.  No use shall be allowed within a regulatory floodway which: a.  Acting alone or in combination with existing or future uses creates a danger or hazard to life or property; b.  Increases the water surface elevation of the base flood; or c.  Adversely affects groundwater recharge. D.  If this section is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions in this article. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-5-8 Floodway Fringe Area Requirements. A.  Floodway fringe areas shall be subject to the following regulations: 1.  The following uses shall be permitted within a floodway fringe area to the extent that they are not prohibited by any other ordinance, and only upon issuance of a floodplain use permit: a.  Any use permitted in Section 17-5-7, Floodways; b.  Any other use not involving structures, provided it is elevated above the regulatory base flood elevation and a determination is made by the Town Engineer that the use will not increase the base flood elevation more than one (1) foot where the owner of the land doing Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 33 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. the development owns both sides of the floodway, and not more than one-tenth (0.1) foot where only one (1) side is owned. In no case shall the development increase the water surface elevation more than one-tenth (0.1) foot on the property owned by others upstream and downstream, nor unduly restrict the capacity of the channels or floodway of tributaries to the main stream or watercourse, drainage ditches, or other drainage facilities or systems. The aforementioned water surface elevation increases apply to all watercourse channels in Oro Valley except the Canada del Oro Wash where the elevation of the existing levee system and bank protection will allow for no water surface elevation increases due to encroachment. Additionally, when main channel floodflow velocities are greater than four (4) feet per second (fps), a land use/development activity shall not increase floodflow velocities immediately downstream of the activity by more than one (1) fps or ten percent (10%), whichever is less, in the regulatory floodway. Any velocity increase greater than the aforementioned criteria must be reviewed and approved by the Town Engineer; c.  Structures, including dwellings, may be erected or moved, provided the lowest floor or basement floor is placed at or above the regulatory flood elevation. Land may be filled; provided, that the top of such fill shall be at or above the regulatory flood elevation for the particular area, and unless structurally protected from erosion shall extend at such elevations at least twenty-five (25) feet beyond the limits of any structure erected or placed thereon. Where structural protection from erosion is provided, the minimum extent to which tops of the fill pad must extend shall not be less than fifteen (15) feet. The placement of structures and any accompanying fill shall not affect base flood elevation beyond the limits set in subsection (A)(1)(b) of this section. B.  The following minimum requirements apply to all uses located within a regulatory floodplain: 1.  All new construction (including prefabricated structures and mobile homes) and substantial improvements shall be anchored to prevent flotation and lateral movement, and be constructed with flood resistant materials and methods. 2.  All proposed plats and proposals for other developments, including their utilities, streets, and drainage structures, shall be located and designed to be consistent with the need to minimize flood damage. 3.  All tentative development plans, site plans, final site plans, improvement plans, and final plats, and other proposed new developments shall include base flood elevation data or as otherwise directed by the Town Engineer. 4.  If in a riverine situation, all adjacent communities and the State Coordinating Office must be notified prior to any alteration or relocation of the watercourse, and copies of such notifications must be sent to the FEMA. Within the proposed altered or relocated portion of any watercourse, the flood carrying capacity shall be maintained. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 34 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 5.  Within one hundred twenty (120) days after completion of construction of any flood control protective works which changes the rate of flow during the flood, or changes the configuration of the floodplain, the person or agency responsible for installation of the protective works shall provide to the governing bodies of all jurisdictions affected by the protective works a new delineation of all floodplains affected. The new floodplain delineation shall be done according to the criteria adopted by the State of Arizona Director of Water Resources. C.  Limitations. 1.  No use shall be allowed within a floodway fringe which: a.  Acting alone or in combination with existing or future uses creates danger or hazard to life or property; b.  Increases the water surface elevation for the base flood by more than that allowed under subsection (A)(1)(b) of this section; c.  Adversely affects groundwater recharge. D.  Critical Facilities. 1.  “Critical facility” means any of the following: a.  A structure or facility that produces, uses or stores highly volatile, flammable, explosive, toxic, and/or water-reactive materials; b.  Hospitals, emergency medical facilities, nursing homes and/or housing facilities likely to have occupants who may not be sufficiently mobile to avoid injury or death during a flood; c.  Essential emergency response facilities, such as police stations, fire stations, emergency shelters and/or operation centers that are needed for public safety and/or flood response activities before, during and after a flood; and d.  Public and private utility facilities, such as but not limited to power, water and wastewater treatment, and/or communications, that are vital to maintaining or restoring normal services to flooded areas before, during and after a flood. 2.  Applicability. The critical facility requirements shall only apply along watercourses which have FEMA designated floodplains. Where the two-tenths percent (0.2%) chance floodplain has not been established, the Town Engineer may require that this floodplain be delineated by the applicant. 3.  Critical facilities shall be located outside of the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, if possible. If a critical facility must be located in a two- tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, it must be Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 35 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. demonstrated that there is either a critical need to locate it within the floodplain, or that there is not a suitable alternative site, as justified by an Arizona registered professional engineer. Any critical facility located within a two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain shall be protected from that event. “Protection” includes, but is not limited to, elevating the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all weather access during the base flood and developing an emergency response plan. 4.  Existing critical facilities within the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain that propose substantial improvements and/or repairs shall be protected from the two-tenths percent (0.2%) annual chance (five hundred (500) year) flood event. “Protection” includes, but is not limited to, elevating or flood-proofing the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two -tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all-weather access to the base flood and developing an emergency response plan. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-5-9 Flood-Related Erosion-Prone Area. The protection of Town residents and their property from injury and damage that can occur as a result of streambank lateral migration due to erosion and scour is of primary importance in the administration of this chapter and the following criteria apply: A.  The Floodplain Administrator shall require Floodplain Use Permits for proposed construction and other development within all flood-related erosion-prone areas, as determined by lateral migration analysis described in the Town’s drainage criteria manual or in other predetermined, documented evidence. Areas generally most susceptible to lateral erosion and scour include, but are not limited to, locations of historical stream/wash meandering, locations where poorly defined or poorly consolidated banks occur, wash reaches characterized by changes in the direction, velocity, or amount of streamflow, and locations in the proximity of stabilizing features or structures such as rock outcrops or bridges. Alternative safe limits for erosion setbacks may be considered if approved in writing by the Floodplain Administrator based on an acceptable engineering study prepared and sealed by an Arizona registered professional engineer. However, at no time shall a setback be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for a protected bank. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 36 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. B.  Permit applications shall be reviewed to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion, and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard. C.  If a proposed development or structure including associated permanent features such as a patio wall or swimming pool or any other feature is found to be in the path of flood-related erosion, or would increase the erosion hazard, such improvements shall be relocated or adequate protective measures shall be taken to avoid aggravating the existing erosion hazard. D.  Areas within the erosion setback may be used for suitable open space purposes, such as for outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-6 APPEAL AND VARIANCE PROCEDURES Sections: 17-6-1 Nature of Variances 17-6-2 Floodplain Board 17-6-3 Appeals and Request for Variance Considerations 17-6-4 Conditions for Variances 17-6-1 Nature of Variances. The variance criteria set forth in this article are based on the general principle of zoning law that variances pertain to a piece of property and are not personal in nature. A variance may be granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter would create an exceptional hardship to the applicant or the surrounding property owners. The characteristics must be unique to the property and not be shared by adjacent parcels. The unique characteristic must pertain to the land itself, not to the structure, its inhabitants, or the property owners. It is the duty of the Town of Oro Valley to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring a structure built below the regulatory flood elevation are so serious that variances from the regulatory flood elevation shall not be granted. Variances from other requirements in the floodplain management ordinance are quite rare. The long- term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 37 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. screen out those situations in which alternatives other than a variance are more appropriate. ((O)21- 06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-6-2 Floodplain Board. A.  The Floodplain Board of Oro Valley shall hear and decide requests for variances from the requirements of this chapter to FEMA regulated floodplains, as well as hear appeals to decisions from previous determinations or actions on non-FEMA regulated floodplains by the Floodplain Administrator or the Town Engineer. B.  The Floodplain Board shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Floodplain Administrator in the enforcement or administration of this chapter with regard to FEMA regulated floodplains and floodplains identified on the Town’s Flood Insurance Rate Maps. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) 17-6-3 Appeals and Request for Variance Considerations. A.  In considering appeals and requests for variance, the Floodplain Board shall consider all technical evaluations, all relevant factors, and all standards specified in other sections of this chapter, and also consider: 1.  The danger that materials may be swept onto other lands to the injury of others; 2.  The danger of life and property due to flooding or erosion damage; 3.  The susceptibility of the proposed facility and its contents to flood damage, and the effect of such damage on the individual owner; 4.  The importance of the services provided by the proposed facility to the community; 5.  The necessity to the facility of a waterfront location, where applicable; 6.  The availability of alternative locations for the proposed use that are not subject to flooding or erosion damage; 7.  The compatibility of the proposed use with existing and anticipated development; 8.  The relationship of the proposed use to the comprehensive plan and floodplain management program for the area encompassing the proposed use; 9.  The safety of access to the property in time of flood for ordinary and emergency vehicles; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 38 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 10.  The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and 11.  The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, water system, and streets and bridges. B.  Upon consideration of the factors of subsection (A) of this section and the purposes of this chapter, the Floodplain Board may attach such conditions to the granting of appeals and variances as it deems necessary to further the purposes of this chapter. C.  The Floodplain Administrator shall maintain a record of all variance actions, including justification for their issuance, and shall report any such variances that are issued in FEMA regulated floodplains in its biennial report, which is also submitted to the Federal Emergency Management Agency. D.  Any applicant to whom a variance is granted shall be given written notice over the signature of the Floodplain Administrator, or their designee, that: 1.  The issuance of a variance to construct a structure below the base flood elevation will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage; and 2.  Such construction below the regulatory flood elevation increases risks to life and property; and 3.  The land upon which the variance is granted shall be ineligible for exchange of State land pursuant to the flood relocation and land exchange program provided by ARS § 37-610. A copy of the notice shall be recorded in the office of the Pima County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. E.  A person aggrieved in any manner by an action of the Floodplain Board may within thirty (30) days appeal to the Floodplain Board. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-6-4 Conditions for Variances. A.  Variances shall only be issued upon: 1.  A showing of good and sufficient cause; 2.  A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief; 3.  A determination that failure to grant the variance would result in exceptional hardship to the applicant; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 39 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 4.  A showing that the use cannot perform its intended purpose unless it is located or carried out in close proximity to water. This includes only facilities defined in Article 17-2 in the definition of “functionally dependent use” (which is unlikely due to the Town of Oro Valley’s arid climate); and 5.  A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances. B.  Variances shall not be issued within any regulatory floodway if any increase in the base flood elevation would result. C.  Variances may be issued for the repair, rehabilitation, or restoration of structures listed in the National Register of Historic Places or the State Inventory of Historic Places upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as a historic structure, and that the variance is the minimum necessary in order to preserve the historic character and design of the structure. D.  The Floodplain Administrator, at his/her discretion, may grant a variance for non-FEMA regulated flood hazard areas. E.  Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (0.5) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the regulatory flood elevation, provided the procedures of Articles 17-4 and 17-5 have been fully considered. As the lot size increases beyond one-half (0.5) acre, the technical justification required for issuing the variance increases. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-7 ORDINANCE AMENDMENTS Sections: 17-7-1 Procedures 17-7-1 Procedures. A.  The Floodplain Board may from time to time, after a public hearing required by law (ARS § 38- 431.01, and other open meeting laws), amend, supplement, or change the regulations set forth herein or subsequently established. Any amendment, supplement, or change may be initiated by the Floodplain Board or by petition of affected persons hereafter provided. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 40 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. B.  The procedures established by this article are to provide for appropriate and timely ordinance amendments, with due consideration of the purpose of this article. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) Article 17-8 FEES Sections: 17-8-1 Fee Schedule 17-8-1 Fee Schedule. Fees for floodplain use permits will be charged based on the fee schedule approved by the Town Council. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. Disclaimer: The Town Clerk’s Office has the official version of the Oro Valley Town Code. Users should contact the Town Clerk’s Office for ordinances passed subsequent to the ordinance cited above. Town Website: www.orovalleyaz.gov Hosted by General Code. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 1 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. CHAPTER 17 FLOODPLAIN AND EROSION HAZARD MANAGEMENT Articles: 17-1 Statutory Authorization, Findings of Fact, Purpose and Methods 17-2 Definitions 17-3 General Provisions 17-4 Administration 17-5 Provisions for Flood Hazard Reduction 17-6 Appeal and Variance Procedures 17-7 Ordinance Amendments 17-8 Fees Article 17-1 STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS Sections: 17-1-1 Statutory Authorization 17-1-2 Findings of Fact 17-1-3 Statement of Purpose 17-1-4 Methods of Reducing Flood Losses 17-1-1 Statutory Authorization. The Legislature of the State of Arizona has, in ARS § 48-3610, enabled the Town of Oro Valley to assume the powers and duties for floodplain management and adopt regulations in conformance with ARS § 48-3609 that are designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the Town Council of Oro Valley, Arizona, does ordain as follows. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-2 Findings of Fact. A.  The regulatory floodplains of Oro Valley are subject to periodic inundation that may result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 2 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare. B.  These flood losses are caused by the cumulative effect of obstructions in regulatory floodplains, which increase flood heights and velocities. Also, when these obstructions are inadequately anchored, they may cause damage in other areas. Uses that are inadequately flood-proofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-3 Statement of Purpose. It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed: A.  To protect human life and health; B.  To minimize expenditure of public money for costly flood control projects; C.  To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; D.  To minimize prolonged business interruptions; E.  To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone, and sewer lines, and streets and bridges located in regulatory floodplains; F.  To help maintain a stable tax base by providing for the sound use and development of the regulatory floodplain and erosion hazard areas so as to minimize blight areas caused by flooding; G.  To ensure the state mandated required regulatory floodplain information is available to potential buyers; H.  To regulate activities within regulatory floodplains for both public and private properties; I.  To participate in and maintain eligibility for flood insurance and disaster relief. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-1-4 Methods of Reducing Flood Losses. In order to accomplish its purposes, this chapter includes methods and provisions for: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 3 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. A.  Restricting or prohibiting uses which are dangerous to the public health, safety, and welfare as well as public and private property, due to water or development hazards; or which result in increased damages to development or increases in flood heights or velocities; B.  Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of start of construction; C.  Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help to accommodate natural flood storage potential or the channelization of floodwaters; D.  Controlling filling, grading, dredging, and other development that may increase flood damage; and E.  Preventing or regulating the construction of flood barriers that unnaturally divert floodwaters, or that may increase flood hazards in other areas. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) Article 17-2 DEFINITIONS Sections: 17-2-1 Definitions 17-2-1 Definitions. Unless specifically defined below, words or phrases used in this chapter shall be interpreted to give them the meaning they have in common usage, and to give this chapter its most reasonable application. “Accessory structure” means a structure that is on the same parcel of property as a principal structure, the use of which is incidental to the use of the principal structure. For floodplain management purposes, the term must be used only for parking or storage, must be small, represent a minimal investment, and have low damage potential. FEMA considers ‘small’ to mean not larger than a one-story two-car garage. Examples include detached garages, storage sheds, tool sheds, and small boathouses. “Appeal” means a request for a review of the Floodplain Administrator’s interpretation of any provision of this chapter or a request for a variance. Appeals are heard and decided by the Floodplain Board. “Area of shallow flooding” means a designated zone AO or AH on a community’s Flood Insurance Rate Map (FIRM) with a one percent (1%) or greater annual chance of flooding to an average depth Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 4 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. of one (1) to three (3) feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. “Base flood” means a flood having a one percent (1%) chance of being equaled or exceeded in any given year. “Base flood elevation (BFE)” means the computed elevation to which floodwater is anticipated to rise during the base flood. “Basement” means any area of a structure with a subgrade floor (i.e., below the adjacent ground level) on all sides. Building. See “Structure.” “Community” means any state or area or political subdivision thereof, or any Indian tribe, authorized tribal organization, or authorized Native organization, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction. Critical Facility. Refer to Section 17-5-8(D). “Detention system” means a type of flood control system which delays the downstream progress of floodwaters in a controlled manner, generally through the combined use of a temporary storage area and a metered outlet device, which causes a lengthening of the duration of the flow and thereby reduces downstream flood peaks. “Development” means any manmade change to improved or unimproved real estate, including but not limited to structures, mining, dredging, filling, grading, paving, excavation or drilling operations, and storage of materials and equipment. “Dwelling” means a habitable structure. “Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that is used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a letter of map amendment (LOMA) or letter of map revision based on fill (LOMR-F). “Encroachment” means the advance or infringement of uses, human-installed or human-maintained landscape vegetation, fill, excavation, permanent structures, or development into a floodplain that may impede or alter the flow capacity of a floodplain. An equal degree of encroachment is a standard applied to the evaluation of the effects of the encroachment on increases in flood heights. It assumes that an encroachment, if permitted, may confer on all property owners on both sides of the watercourse an equal right to encroach to the same degree within that reach. Since the factors affecting hydraulic efficiency are usually not uniform within a reach, this standard will usually not Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 5 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. result in equal measured distances between the regulatory floodway and the regulatory floodplain of the watercourse. “Erosion” means the process of the gradual wearing away of landmasses. This peril is not, per se, covered under the National Flood Insurance Program. “Erosion hazard area” means lands adjoining a watercourse that is regulated by this chapter which are deemed by the Town Engineer to be subject to flood-related erosion, pursuant to the Town’s adopted drainage criteria manual. “Erosion setback” means the minimum horizontal distance between a structure or permanent feature and the channel bank necessary to protect the structure/feature from flood-related erosion damage. For method to be used for determination of the erosion setback, see the adopted Town of Oro Valley drainage criteria manual. “Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are affixed (including, at a minimum, the installation of utilities, construction of streets, and either final site grading or the pouring of concrete slabs) was completed before December 4, 1979, the effective date of the Flood Insurance Rate Maps adopted by the Town of Oro Valley. “Expansion to an existing manufactured home park or subdivision” means preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads). “Federal Emergency Management Agency (FEMA)” means an agency of the Federal government responsible for programs of disaster response and recovery, disaster preparedness, hazard mitigation, flood insurance, and other programs of technical and financial assistance. “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) the overflow of floodwaters; (2) the unusual and rapid accumulation or runoff of surface waters from any source; and/or (3) the collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in this definition. “Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Emergency Management Agency has delineated both the special flood hazard areas and the risk premium zones applicable to the community. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 6 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Flood Insurance Study (FIS)” means the official report provided by Federal Emergency Management Agency that includes flood profiles, the Flood Insurance Rate Map, and the water surface elevation of the base flood. “Flood protection system” means those physical structural works for which funds have been authorized, appropriated, and expended; and which have been constructed specifically to modify flooding in order to reduce the extent of the area within a community subject to designation as a regulatory floodplain as well as the extent and depths of associated flooding. Such a system typically includes dams, reservoirs, levees or dikes. These specialized flood-modifying works are those constructed in conformance with sound engineering standards. “Floodplain” or “flood-prone area” means any land area susceptible to being inundated by water from any source (see “flood” or “flooding”). “Floodplain Administrator” means the Town Engineer, or their designee, whose duty it is to oversee administration and enforcement of the floodplain management regulations contained in this chapter. “Floodplain Board” means the Town Council of Oro Valley, at such times as they are engaged in the enforcement of this chapter. “Floodplain management” means the operation of an integrated natural resource management program encompassing corrective and preventive measures for reducing flood and erosion damage. Floodplain management includes but is not limited to emergency preparedness planning, flood control works, floodplain management regulations, and open space plans. “Floodplain management regulations” means this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control), and other applications of legal and regulatory authority that control use of, and development in, flood-prone areas. This term describes Federal, State, or local regulations, and any combination thereof, which provide standards for preventing and reducing flood loss and damage. “Floodplain use permit” (also “permit for development in a floodplain”) means an official document that authorizes special activity within regulatory floodplains or erosion hazard areas of Oro Valley. “Flood-proofed” or Dry Floodproofed means a building or structure that has been made watertight with walls substantially impermeable to the passage of water, and structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy, accomplished by means other than elevation. “Flood-proofing” means any combination of structural and nonstructural additions, changes, or adjustments to nonresidential structures that reduces or eliminates flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents by means other than elevation. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 7 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Flood-related erosion” means the collapse or subsidence of land along the shore of a lake or other body of water as a result of undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding. Floodway. See “regulatory floodway.” “Floodway fringe” means that area of the floodplain lying on either side of a regulatory floodway where encroachment may be permitted. “Functionally dependent use” means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long-term storage or related manufacturing facilities. “Governing body” is the local governing unit (i.e., county or municipality) empowered to adopt and implement regulations providing for the public health, safety, and general welfare of its citizenry. “Hardship” means that the physical characteristics of the property in question are so unusual, exceptional, and peculiar to the property that a variance regarding its use may be requested and granted in accordance with Section 17-6-1. Mere economic or financial hardship alone is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one’s neighbors likewise cannot, as a rule, be construed to qualify as an exceptional hardship. All of these problems can be resolved through other means without granting a variance, even if the alternative is more expensive, requires the property owner to build elsewhere, or means that the parcel must be put to a different use than originally intended. “Highest adjacent grade” means the highest natural elevation of the ground surface immediately adjacent to a structure prior to construction of the proposed walls of a structure. “Historic structure” means any structure that is: 1.  Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; 2.  Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; 3.  Individually listed on the State of Arizona inventory of historic places, as approved by the Secretary of the Interior; or Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 8 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 4.  Individually listed on the Town of Oro Valley’s inventory of historic places and that has been certified by an approved State of Arizona program, as determined by the Secretary of the Interior. “Landscape vegetation” means vegetation that is installed, planted, irrigated, maintained, or otherwise placed or modified by human activity. Naturally occurring native vegetation within the floodplain is not considered landscape vegetation. “Levee” means a human-made structure, usually an earthen embankment designed and constructed in accordance with sound engineering practices, for the purpose of containing, controlling, or diverting the flow of water so as to provide protection from temporary flooding. “Lowest floor” means the lowest floor of the lowest enclosed area including the basement (see “basement” definition) or crawl space under a manufactured home if it is not vented. An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered to be the lowest floor of a structure; provided, that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this chapter. “Manufactured home” means a structure, transportable in one (1) or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.” “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale. “Market value” means the determination of the estimated cost to replace the structure in new condition and adjusting that cost figure by the amount of depreciation that has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and functional obsolescence as approved by the Floodplain Administrator but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences. Alternatively, the market value is the valuation made by the Pima County Assessor’s Office. “Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum of 1988 (NAVD ’88), or other datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 9 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “National Flood Insurance Program (NFIP)” means a program administered by FEMA that makes Federally backed flood insurance available for purchase by individuals that live in NFIP participating communities. New Construction. For the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial Flood Insurance Rate Map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures. “Obstruction” includes, but is not limited to, any dam, wall, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, structure, wire, fence, rock, gravel, refuse, fill, structure, vegetation, or other material in, along, across, or projecting into any watercourse which may alter, impede, retard, or change the direction and/or velocity of the flow of water, or which due to its location influences its propensity to snare or collect debris carried by the flow of water, thereby reducing its likelihood of being carried downstream as well as reducing the channel’s ability to convey flow. “One hundred (100) year flood” means the flood having a one percent (1%) chance of being equaled or exceeded in any given year (see “base flood”). Also referred to as the one percent (1%) annual exceedance probability flood (one percent (1%) AEP flood). “Permit for development in a floodplain” (also referred to as a “floodplain use permit”) is an official document issued by the Town of Oro Valley authorizing performance of specific activity in any regulatory floodplain or erosion hazard area after it has been determined to be reasonably safe from flooding and erosion. These permits are required to ensure that proposed development projects meet the requirements of the NFIP and the provisions of this chapter. Examples include grading permits, building permits, and floodplain use permits. “Person” means an individual, firm, partnership, association or corporation, or agent of the aforementioned groups, or the State of Arizona or its agencies or political subdivisions. “Program” means the National Flood Insurance Program authorized by 42 U.S.C. 4001 through 4128, or as authorized by subsequent Federal statutes. “Reach” is a hydraulic engineering term to describe longitudinal segments of a stream or watercourse. A reach will generally include the segment of the flood hazard area where flood heights are primarily controlled by manmade or natural obstructions or constrictions. In an urban area, an example of a reach would be the segment of a stream or watercourse between two (2) consecutive bridge crossings. “Recreational vehicle” means a vehicle that is: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 10 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Built on a single chassis; 2.  Four hundred (400) square feet or less in area, when measured at the largest horizontal projection; 3.  Designed to be self-propelled or permanently towable by a light duty truck; and 4.  Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. “Regulatory flood elevation” means the base flood elevation plus one (1) foot of freeboard as required by this chapter. “Regulatory floodplain or flood-prone area” means that portion of the geologic floodplain associated with a watercourse, including its channel, or any other floodplain or flood-prone area that would be inundated by the base flood, including all base floods where the base flood peak discharge is one hundred (100) cubic feet per second or greater, those areas that are subject to sheet flooding except when the maximum potential contributing watershed area is less than twenty (20) acres, those areas identified on subdivision plats or development plans, those areas designated by FEMA, including areas designated as shaded Zone X as well as those areas that the Floodplain Administrator, using the best available data, has determined is subject to a flood hazard during the base flood. “Regulatory floodway” means the channel of a watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated amount. “Remedy a violation” means to bring the structure or other development into compliance with State or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of this chapter, otherwise deterring future similar violations, or reducing Federal financial exposure with regard to the structure or other development. “Repetitive loss structure” means a structure, covered by a contract for flood insurance issued pursuant to the National Flood Insurance Act, that has incurred flood-related damage on two (2) occasions during any ten (10) year period ending on the date of the event for which a second claim is made, and for which the cost of repairing the flood damage, on average, equaled or exceeded twenty-five percent (25%) of the market value of the structure at the time of each such flood event. In addition to the current claim, the NFIP must have paid the previous qualifying claim. “Retention system” means a type of flood control system that stops the downstream progress of floodwater by employing methods of total containment which generally involve creation of storage areas that incorporate infiltration devices, such as dry wells, to dispose of stored waters, principally Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 11 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. by percolation over some specified period of time, thereby eliminating basin contributions to downstream flood peaks or flood volumes. “Riverine” means relating to, formed by, or resembling a river (including tributaries), stream, brook, etc. Sheet Flow Area. See “area of shallow flooding.” “Special flood hazard area (SFHA)” means an area in the regulatory floodplain subject to a one percent (1%) or greater chance of flooding in any given year. SFHAs are shown on a Flood Insurance Rate Map as Zone A, AO, AE, AH or A0. “Start of construction” includes substantial improvement or other proposed new development, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within the time period when the permit was active. The “actual start” means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation such as the installation of streets and/or walkways, the installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the “actual start of construction” means the first alteration of any wall, ceiling, floor or other structural part of a structure, whether or not that alteration affects the external dimensions of the structure. “Storage” Contents stored in wet floodproofed structures will get wet during flooding. “Structure” means a walled and roofed building, including gas or liquid storage tanks, principally above ground and affixed to a permanent site. This term also refers to a manufactured home on a permanent foundation. “Structure Size” The footprint of a typical two-car garage is about 600 square feet in area. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred. “Substantial improvement” means any reconstruction, rehabilitation, addition, or other improvement to a structure, the total cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 12 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local Code Enforcement Official and which are the minimum necessary to assure safe living conditions; or 2.  Any alteration of a “historic structure”; provided, that the alteration will not preclude the structure’s continued designation as a “historic structure.” “Variance” means a grant of relief from the requirements of this chapter that is granted by the Floodplain Administrator or the Floodplain Board (for FEMA floodplains) upon a finding that strict enforcement of the provisions would cause undue hardship owing to circumstances unique to the individual property for which the variance is granted, and not caused by the applicant for said variance. “Violation” means the failure of a structure or other development to be fully compliant with the Town of Oro Valley floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required by this chapter is presumed to be in violation until such time as such documentation is provided. “Violation” also means unauthorized construction, grading, encroachment, diversion, or lack of maintenance of private drainage structures. “Water surface elevation” means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929 or the North American Vertical Datum (NAVD) of 1988 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of riverine and sheet- flow areas. “Watercourse” means a lake, river, creek, stream, wash, arroyo, channel, or other topographic feature on or over which waters flow at least periodically. “Watercourse” includes specifically designated areas in which substantial flood damage may occur, including regulatory floodplains as designated by FEMA or the Town of Oro Valley. “Zone A (unnumbered)” is a special flood hazard area identified by FEMA that is subject to inundation from a one hundred (100) year flood event. Because detailed hydraulic analyses have not been performed, no base flood elevation or depths are shown. Mandatory flood insurance requirements apply. “Zone AE” is a special flood hazard areas subject to inundation by the one hundred (100) year flood determined by a Flood Insurance Study (FIS). Base flood elevations are shown within these zones and mandatory flood insurance requirements apply. “Zone AH” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding (usually areas of ponding) with average depths between one (1) and three (3) feet. Base flood elevations derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance requirements apply. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 13 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. “Zone AO” is a special flood hazard area subject to inundation by one hundred (100) year shallow flooding, usually resulting from sheet flow on sloping terrain, with average depths between one (1) and three (3) feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. Mandatory flood insurance requirements apply. “Zone X shaded” (or “shaded Zone X”) is an area determined by a Flood Insurance Study as having moderate or minimal hazard from flooding. There are four classifications depending on location: (1) area of one hundred (100) year flood with average depths of less than one (1) foot; (2) area with drainage areas less than one (1) square mile; (3) area protected by an accredited levee from one hundred (100) year flood; and (4) area of five hundred (500) year flood. Buildings or other improvements in this zone could be flooded by severe, concentrated rainfall, in the absence of adequate drainage systems. Flood insurance is available in participating communities, but it is not required. In the Town of Oro Valley only the third classification applies (i.e., protected by levees). ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-3 GENERAL PROVISIONS Sections: 17-3-1 Lands to Which This Chapter Applies 17-3-2 Basis for Establishing the Regulatory Floodplain Areas 17-3-3 Compliance 17-3-4 Abrogation and Greater Restrictions 17-3-5 Interpretation 17-3-6 Statutory Exceptions 17-3-7 Floodplain Violations 17-3-8 Abatement of Violations 17-3-9 Unlawful Acts 17-3-10 Remedies 17-3-11 Severability 17-3-12 Warning and Disclaimer of Liability 17-3-1 Lands to Which This Chapter Applies. This chapter shall apply to all regulatory floodplain areas within the corporate limits of the Town of Oro Valley, including special flood hazard areas, floodplains shown on recorded subdivision plat maps, as well as those areas identified by the Floodplain Administrator, using the best available data. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 14 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-3-2 Basis for Establishing the Regulatory Floodplain Areas. The special flood hazard areas identified by the Federal Emergency Management Agency (FEMA) in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for Pima County, Arizona and Incorporated Areas,” revised September 28, 2012, with accompanying Flood Insurance Rate Maps (FIRMs) dated June 16, 2011, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This (FIS) and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter, and which are recommended to the Floodplain Board by the Floodplain Administrator. The Floodplain Board, within the incorporated limits of the Town of Oro Valley, shall require developers of land to delineate, within areas where development is ongoing or imminent, floodplains consistent with the criteria developed by FEMA, the Arizona Director of Water Resources, and the Town Engineer, pursuant to the Town’s adopted drainage criteria manual. The FIS and FIRMs are on file at the Town of Oro Valley Public Works Department. A.  Regulatory floodplains shall be subject to requirements in Section 17-5-8 (Floodway Fringe Area Requirements). B.  Elevation and Boundary Refinements. 1.  The determination of elevations (water surface, lowest finished floor, and adjacent land) and regulatory floodway and regulatory floodplain boundaries is an engineering function with calculations and decisions made in accordance with the concepts and policies set forth in this chapter. The best technical data available shall be used for such calculations and decisions. Initial determinations shall be based on floodplain information reports of the Pima County Flood Control District, U.S. Corps of Engineers, U.S. Bureau of Reclamation, U.S. Geological Survey, and/or other general data that are pertinent for the conditions of the streams or the watercourses at the time the data are obtained. 2.  Additional and more detailed technical analysis will, from time to time, become available through private or governmental studies and activities. This data will permit refinements in the elevations and boundaries of the regulatory floodway and regulatory floodplains in the respective reaches of the streams or watercourses. 3.  Whenever such additional data become available and it seems desirable to make refinements, i.e., letter of map amendments (LOMAs) or letter of map revisions (LOMRs), such refinements or revisions may be made at the request of the property owners or developers or by the Town Engineer. The necessary engineering calculations shall be made for the property owner or developer by an Arizona registered professional engineer (at the owner’s/developer’s expense) in conformance with requirements of this chapter, the FEMA, and the Arizona Department of Water Resources (ADWR). These findings will need approval of the Town Engineer. Following the Town’s approval of these refinements to regulatory floodplain areas Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 15 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. identified on FIRMs, the property owner shall have calculations and forms forwarded to FEMA for review and approval. 4.  The Town Engineer or their duly designated representative shall have the authority and responsibility to revise and refine elevations and boundaries of regulatory floodways and regulatory floodplains whenever such revisions and refinements are for the purpose and in accordance with the conditions set forth in Sections 17-4-3(B)(1)(d), 17-5-8(B)(3), (4), and (5). a.  The Flood Insurance Rate Map for Pima County and incorporated areas shall be revised to show the refined area boundaries and/or elevations. b.  The Town Engineer shall notify the owner of each property for which area boundaries and/or elevations have been revised or refined, as well as those owners of adjoining property immediately upstream and downstream, by first class mail following a duly noticed public hearing on the property involved. c.  An appeal to the Floodplain Board may be taken by any person aggrieved, in accordance with Article 17-6. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-3 Compliance. All development of land, construction of residential, commercial, or industrial structures, or future development within regulatory floodplain areas is subject to the terms of this chapter and any other applicable regulations. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-4 Abrogation and Greater Restrictions. The provisions of this chapter are not intended to interfere with, abrogate, or annul any ordinance, rule, regulations, or permit previously adopted or issued, and not be in conflict with any provision of this chapter or any regulation that shall be adopted or issued pursuant to law relating to the use of structure or ordinance not in conflict with this chapter; nor is it intended by this chapter to interfere with or abrogate or annul any easement, covenant, or other agreement between parties, except when this chapter imposes a greater restriction, this chapter shall control. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-5 Interpretation. In the interpretation and application of this chapter, all provisions shall be: A.  Considered as minimum requirements; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 16 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. B.  Liberally constructed in favor of the governing body; and C.  Deemed neither to limit nor repeal any other powers granted under State statutes. ((O)21-06, 11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-6 Statutory Exceptions. A.  In accordance with ARS § 48-3609(I), unless expressly provided this and any regulations adopted pursuant to this article do not affect: 1.  Existing legal uses of property or the right to continuation of such legal use. However, if a nonconforming use of land or a structure is discontinued for twelve (12) months or destroyed to the extent of fifty percent (50%) or more of its market value, as determined by a competent appraiser, or the valuation made by the Pima County Assessor’s Office, any further use shall comply with this article and regulations of the Town of Oro Valley. 2.  Reasonable repair or alteration of property for the purposes for which the property was legally used on August 3, 1984, or any regulations affecting such property takes effect, except that any alteration, addition, or repair to a nonconforming structure which would result in increasing its flood damage potential by fifty percent (50%) or more shall be either flood-proofed or elevated to or above the regulatory flood elevation. 3.  Reasonable repair of structures constructed with the written authorization required by ARS § 48-3613. 4.  Facilities constructed or installed pursuant to a certificate of environmental compatibility issued pursuant to ARS Title 40, Chapter 2, Article 6.2. B.  Before the following types of construction authorized by ARS § 48-3613(B) may begin, the responsible person must submit grading plans and a grading permit application for review and comment. Written authorization is not required for, nor shall the floodplain board prohibit, the following pursuant to ARS § 48-3613(C): 1.  The construction of bridges, culverts, dikes, and other structures necessary for the construction of public highways, roads, and streets intersecting or crossing a watercourse. 2.  The construction of storage dams for watering livestock or wildlife, structures on banks of a watercourse to prevent erosion of, or damage to, adjoining land, if the structure will not divert, retard or obstruct the natural channel of the watercourse, or dams for the conservation of floodwaters as permitted by ARS Title 45, Chapter 6. 3.  The construction of tailing dams and waste disposal areas for use in connection with mining and metallurgical operations. This subsection does not exempt those sand and gravel Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 17 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. operations that will divert, retard or obstruct the flow of waters in any watercourse from complying with, and acquiring authorization from, the Town Engineer or the Floodplain Board pursuant to regulations adopted by the Floodplain Board under this article. 4.  Other construction, if it is determined by the Town Engineer that a floodplain use permit is unnecessary. 5.  Any flood control district, county, city, town, or other political subdivision from exercising powers granted to it under ARS Title 48, Chapter 21, Article 1. 6.  The construction, by a public agency or political subdivision, of streams, waterways, lakes, and other auxiliary facilities in conjunction with development of public parks and recreation facilities. 7.  The construction and erection of poles, towers, foundations, support structures, guy wires, and other facilities related to power transmission as constructed by any utility, whether a public service corporation or a political subdivision. C.  In accordance with ARS § 48-3613(D), in addition to other penalties or remedies otherwise provided by law, the State of Arizona, a political subdivision thereof, or a person who may be damaged or has been damaged as a result of the unauthorized diversion, retardation, or obstruction of a watercourse has the right to go through an administrator/board to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate this section or regulations adopted pursuant to ARS Title 48, Chapter 21, Article 1. If a person is found to be in violation of this section, the administrator/board shall require the violator either to comply with this section, if authorized by the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), or to remove the obstruction and restore the watercourse to its original state. The court may also award such monetary damages as are appropriate to the injured parties resulting from the violation, including reasonable costs and attorney fees. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-7 Floodplain Violations. A.  Declaration of Public Nuisance. All development located or maintained within any regulatory floodplain area after August 8, 1973, in violation of this chapter, and without written authorization from the Floodplain Board for FEMA regulated floodplains (the Town Engineer for non-FEMA regulated floodplains), is a public nuisance per se, and may be abated, prevented or restrained by action of the Floodplain Board. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 18 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-3-8 Abatement of Violations. Upon discovery of a violation to this chapter, the Floodplain Administrator shall either: A.  Take any necessary action to effect the abatement of such violation; or B.  Order the owner of the property upon which the violation exists to provide whatever additional information may be required for determination by the Floodplain Administrator. Such information must be provided to the Floodplain Administrator within thirty (30) days of such order. Within thirty (30) days, the Floodplain Administrator shall either order the abatement of said violation or shall grant a variance in accordance with the provisions of Section 17-6-4; or C.  For FEMA regulated floodplains (SFHAs), submit to the Federal Emergency Management Agency a declaration for denial of insurance, stating that the property is in violation of a cited State or local law, regulation or ordinance, pursuant to Section 1316 of the National Flood Insurance Act of 1968, and as amended. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-9 Unlawful Acts. A.  It is unlawful for a person to engage in any development or to divert, retard, or obstruct the flow of waters in a watercourse if it creates a hazard to life or property without securing the written authorization required by ARS § 48-3613. Where the watercourse is a delineated floodplain, it is unlawful to engage in any development affecting the flow of waters without securing written authorization required by ARS § 48-3613. B.  When drainage improvements are associated with an approved development plan, subdivision plat or approved engineering report, and are constructed to provide flood protection to remove or reduce flood hazards, including those identified by FEMA or for stormwater quality control, and where those improvements are privately owned, then it shall be the responsibility of the property owner(s) to perform maintenance as necessary to ensure the integrity of said drainage improvements and maintenance of the flood carrying capacity to the designed discharge. For purposes of this chapter, a private drainage improvement is considered a structure. It is unlawful for any person or entity to neglect maintenance responsibilities on private drainage improvements. C.  Any person violating the provisions of this section shall be subject to appeal and variance procedures pursuant to Article 17-6, and penalties pursuant to Article 1-8, Penalties. D.  The Town may issue a written notice to correct to any person who has violated or is in violation of this section. E.  Failure to comply with actions described in and required by the notice to correct may result in a notice of violation and/or stop work order. The written notice shall state the nature of the violation, Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 19 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. the corrective action required, the time frame for the corrective action, and penalties for continued noncompliance. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-10 Remedies. All remedies provided for herein shall be cumulative and not exclusive. The conviction and punishment of any person hereunder shall not relieve such person from the responsibility to correct prohibited conditions or to remove prohibited structures, obstructions, or improvements; nor prevent the enforcement, correction, or removal thereof. In addition to the other penalties or remedies provided in this article, the State of Arizona, any political subdivision thereof, or any person who may be damaged as a result of the diversion, retardation, or obstruction of a watercourse shall have the right to commence, maintain, and prosecute any appropriate action or pursue any remedy to enjoin, abate, or otherwise prevent any person from violating or continuing to violate any provision of this chapter. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-11 Severability. This chapter, and its various parts thereof, is hereby declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any portion thereof, other than the section so declared to be unconstitutional or invalid. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-3-12 Warning and Disclaimer of Liability. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes, and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the regulatory floodplain areas or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the Town of Oro Valley, any officer or employee thereof, the State of Arizona, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05- 35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 20 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. Article 17-4 ADMINISTRATION Sections: 17-4-1 Establishment of Floodplain Use Permits 17-4-2 Enforcement and Inspection 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures 17-4-4 Designation of the Floodplain Administrator 17-4-1 Establishment of Floodplain Use Permits. A.  Responsibility for Permits. It shall be the duty of the Town Engineer acting as the Floodplain Administrator, and all departments, officials, and public employees vested with the duty or authority to issue permits or licenses, to enforce the provisions of this chapter; and no such license or permit shall be issued for uses or buildings where the same would be in conflict with the provisions of this chapter. Any such license or permit, if issued in conflict with the provisions of this chapter, shall be null and void. B.  Floodplain Use Permits. It shall be unlawful to erect, construct, reconstruct, alter, or change the use of any structure within any regulatory floodplain area covered by this chapter without first applying for and obtaining a floodplain use permit from the Town Engineer. C.  Application for Floodplain Use Permit. Application for a floodplain use permit shall be made on forms furnished by the Town Engineer, and must include, without limitation, plans in duplicate drawn to scale showing the nature, location, dimensions, and elevation of the areas in question; existing or proposed structures including walls, bank protection, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required: 1.  Proposed elevation, in relation to mean sea level, of the lowest floor (including basements) of all structures. In a designated Zone AO, elevation of existing highest adjacent natural grade and proposed elevation of lowest floor (including basement) of all structures must be obtained; 2.  Proposed elevation, in relation to mean sea level, to which any nonresidential structure will be flood-proofed; 3.  Certification by an Arizona registered professional engineer or an Arizona registered professional architect that the flood-proofing methods for any nonresidential structure meet the flood-proofing criteria in Section 17-5-1(C); 4.  Base flood elevation data shall be provided for subdivisions or other developments greater than fifty (50) lots or five (5) acres, whichever is the lesser; and Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 21 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 5.  Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. Each such application shall be accompanied by an application fee, as set forth by the Town, payable to the Town of Oro Valley. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-4-2 Enforcement and Inspection. A.  Enforcement. It shall be the duty of the Floodplain Administrator and officials of the Town otherwise charged with the enforcement of the law, to enforce this chapter and all of the provisions of the same. B.  Inspections. Inspections shall be made by officials of the Town duly appointed by the Town Engineer or by a duly appointed Floodplain Administrator. C.  Cooperation. The Town Floodplain Administrator may request, and shall receive so far as may be necessary in the discharge of their duties, the assistance and cooperation of all departments, agencies, officials, and public employees vested with the duty or authority to issue permits, licenses, or to enforce the regulations of this chapter. D.  Town of Oro Valley Administration. Hydrologic, hydraulic, and related floodplain regulations, as well as engineering matters pertaining to the administration and direction of this chapter, shall be referred to the Town of Oro Valley Town Engineer or their designated representative, who shall be responsible for such reviews, advice, and recommendations. E.  Cooperation Agreements and Consultants. The Floodplain Administrator, through the applicable procurement and/or intergovernmental agreement procedures, may retain consultants and experts; and may enter into cooperative agreements for the delineation of floodplains and floodways as well as for such other assistance and guidance considered appropriate and necessary to obtain maximum reasonable protection and benefits under this chapter. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-4-3 Duties of Floodplain Administrator and Use Permit Procedures. A.  The Floodplain Administrator shall issue floodplain use permits required by this section. B.  The following procedure shall be used by the Floodplain Administrator in considering issuance of floodplain use permits: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 22 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Upon receiving an application for a floodplain use permit involving the use of fill, construction of structures, or the storage of materials, and prior to rendering a decision thereon the Floodplain Administrator may: a.  Require the applicant to submit, where applicable, plans in triplicate drawn to scale showing the nature, location, dimensions, and elevations of the lot; existing or proposed structures, fill, storage of materials, flood-proofing measures; and the relationship of the above to the location of the channel, regulatory floodway, regulatory floodplain, the regulatory floodplain with base flood elevations, the proposed project in relation to flood heights and velocities, and the plans for flood protection. The applicant shall provide a new delineation of all regulatory floodplains affected by the project. The new delineation and reports shall be prepared in conformance with FEMA requirements and this chapter. The delineation shall show pre- and post-project floodplain limits and water surface elevations upstream, adjacent, and downstream of the project. b.  Require, where circumstances necessitate more detailed information, the applicant to furnish as much of the following additional information as is deemed necessary by the Floodplain Administrator for the evaluation of the effects of the proposed use upon flood flows and the consideration of other factors necessary to render a decision on suitability of the proposed use: i.  A typical valley cross-section showing the floodway, floodway fringe area, and the floodplain of the watercourse; elevation of land areas adjoining each side of the channel; cross-sectional areas to be occupied by the proposed development; and high water information; ii.  A plan (surface view) showing elevations or contours of the ground; pertinent structure, fill or storage elevations; size, location, and spatial arrangement of all proposed and existing structures on the site; location and elevations of streets, water supply, sanitary facilities; photographs showing existing land uses and vegetation upstream and downstream, and soil types, as well as other pertinent information; iii.  A profile showing the slope of the bottom of the channel or flow line of the watercourse; iv.  Specifications for building construction and materials, flood-proofing, filling, dredging, grading, channel improvement, storage of materials, water supply, and sanitary facilities. c.  Ensure that the proposed development does not adversely affect the carrying capacity of channels at locations where base flood elevations have been determined but a floodway has not been designated. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 23 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. d.  For FEMA regulated floodplains (SFHAs), require the applicant to submit appropriate (e.g., CLOMR, CLOMR-F, LOMR, etc.) applications, forms, and information to FEMA for review and approval. A floodplain use permit shall not be issued by the Town of Oro Valley until after receiving acknowledgement from FEMA of the acceptance of the CLOMR. Additionally, final building permit inspections shall not be made, nor shall certificates of occupancy be given, until after receiving acknowledgement from FEMA that the LOMR has become effective. e.  Ensure other related State of Arizona and Federal permits have been issued. 2.  No permit shall be issued for any development that is not in conformance with this chapter, FEMA regulations, or some other provision of law relating to such development. A floodplain use permit may be denied if the proposed development constitutes a danger or hazard to life or property. C.  The Floodplain Administrator shall be responsible for the following duties: 1.  Obtain and maintain for public inspection and make available the following: a.  Certification of the regulatory flood elevation required in Sections 17-5-1(C)(1), 17-5- 1(C)(2), and 17-5-5; b.  The Zone AO certification required in Section 17-5-1(C)(2); c.  The flood-proofing certification required in Section 17-5-1(C)(3); d.  The certified opening elevation required in Section 17-5-1(C)(4); e.  Review all development permits for improvements and/or damages to existing structures to determine if the application of the substantial improvement rules apply, including establishing a definition of market value determination and verifying that the estimated improvement and/or repair costs are less than fifty percent (50%) of the market value of the structure; f.  Certification of elevation for subdivisions required by Section 17-5-4(E); g.  Certification for floodway encroachments required by Section 17-5-7(A); h.  Records of all variance actions, including justification for their issuance required by Section 17-6-3(C). 2.  Notification of other entities: Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 24 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. a.  Notify adjacent communities and ADWR prior to such alteration or relocation of a watercourse, and submit evidence of such notification to FEMA through appropriate notification means; and b.  Require that the flood carrying capacity of the altered or relocated portion of said watercourse be maintained. 3.  Within one hundred twenty (120) days after completion of construction of any flood control protective works which change the rate of flow during the flood or the configuration of the floodplain upstream or downstream from or adjacent to the project, the person or agency responsible for installation of the project shall provide to the governing bodies of all jurisdictions affected by the project a new delineation of all floodplains affected by the project. The new delineation shall be done according to the criteria adopted by the ADWR. 4.  Advise the Pima County Regional Flood Control District and any adjunct jurisdiction having responsibility for floodplain management in writing and provide a copy of a development plan of all applications for floodplain use permits or variances to develop land in a floodplain or floodway within one (1) mile of the corporate limits of the Town of Oro Valley, Arizona. Also, advise the Pima County Regional Flood Control District in writing and provide a copy of any development plan of any major development proposed within a floodplain or floodway, which could affect floodplains, floodways or watercourses within the district’s area of jurisdiction. Written notice and a copy of the plan of development shall be sent to the district no later than three (3) working days after having been received by Town of Oro Valley. 5.  Notify FEMA of acquisition by means of annexation, incorporation or otherwise, of additional areas of jurisdiction. 6.  A community’s base flood elevations may increase or decrease resulting from physical changes affecting flooding conditions. As soon as practicable, but not later than six (6) months after the date such information becomes available, a community shall notify FEMA of the changes by submitting technical or scientific data in accordance with 44 CFR 65.3. Such a submission is necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements will be based upon current data. 7.  Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 17-3-2 (Basis for Establishing the Regulatory Floodplain Areas), the Floodplain Administrator shall obtain, review and reasonably utilize any base flood elevation data available from a Federal, State, or other source, in order to administer Section 17-5-1 (Standards of Construction). Any such information shall be consistent with the requirements of the Federal Emergency Management Agency and the Director of the Arizona Department of Water Resources and may be submitted to the Floodplain Board for adoption. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 25 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 8.  Make map interpretations, where needed, as to the exact location of the boundaries of the special flood hazard areas (e.g., where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Article 17-6 (Appeal and Variance Procedures). 9.  Take remedial actions on violations of this chapter as required in Section 17-3-8 (Abatement of Violations). ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-4-4 Designation of the Floodplain Administrator. The Town Engineer or their designee is hereby appointed to administer, implement, and enforce this chapter and guidelines set forth in this article by processing floodplain use permits in accordance with its provisions. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-5 PROVISIONS FOR FLOOD HAZARD REDUCTION Sections: 17-5-1 Standards of Construction 17-5-2 Standards for Storage of Materials and Equipment 17-5-3 Standards for Water Supply and Waste Disposal Systems 17-5-4 Standards and Submittal Requirements for Subdivisions 17-5-5 Standards for Manufactured Homes 17-5-6 Standards for Recreational Vehicles 17-5-7 Floodways 17-5-8 Floodway Fringe Area Requirements 17-5-9 Flood-Related Erosion-Prone Area 17-5-1 Standards of Construction. In all regulatory floodplain areas, the following standards are required: A.  Anchoring. 1.  All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 26 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 2.  All manufactured homes shall meet the anchoring standards of Section 17-5-5(B). B.  Construction Materials and Methods. 1.  All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. 2.  All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. 3.  All new construction, substantial improvements, and other proposed new development shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment, as well as other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding. 4.  Within Zone AH or AO, adequate drainage paths around structures on slopes are required to guide floodwaters around and away from proposed structures. C.  Elevation and Flood-Proofing. 1.  New construction and substantial improvement of any structure shall have the lowest floor, including basement, elevated at or above the regulatory flood elevation. In areas without a detailed study but within regulatory floodplain boundaries, the applicant shall have an Arizona registered professional engineer prepare a detailed study to determine the depth of the base flood. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure, the elevation of the lowest floor, including basement, shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor, and provided to the Floodplain Administrator and the Town Building Official. 2.  New construction and substantial improvement of any structure in Zone AO shall have the lowest floor, including basement, higher than the highest adjacent grade at least one (1) foot higher than the depth number on the FIRM, or at least two (2) feet if no depth number is specified. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon completion of the structure an Arizona registered professional engineer or Arizona registered professional land surveyor shall certify to the Floodplain Administrator that the elevation of the structure meets this standard. 3.  Nonresidential construction and new and substantial improvement of any structure shall either be elevated in conformance with subsections (C)(1) and (2) of this section, or together with attendant utility and sanitary facilities: a.  Be flood-proofed so that below the regulatory flood elevation the structure is watertight with walls substantially impermeable to the passage of water; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 27 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. b.  Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and c.  Be certified by an Arizona registered professional engineer or an Arizona registered professional architect that the standards of this subsection are satisfied. Such certifications shall be provided to the Floodplain Administrator and the Town Building Official. 4.  Require, for all new construction and substantial improvements of nonresidential structures, that have fully enclosed areas below the regulatory flood elevation that are usable solely for parking of vehicles, building access, or storage in an area other than a basement, and which are subject to flooding, shall be constructed of flood resistant materials to the regulatory flood elevation, have all service facilities elevated at or above the regulatory flood elevation, and be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by an Arizona registered professional engineer or an Arizona registered professional architect or meet or exceed the following minimum criteria: a.  A minimum of two (2) openings, on different sides of each enclosed area, shall be provided having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. Smaller engineered openings may be allowed if the design is supported by a certification report issued by ICC-ES (International Code Council Evaluation Service), or an equivalent product certification organization. b.  The bottom of all openings shall be no higher than one (1) foot above grade. c.  Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwaters. 5.  Manufactured homes shall meet the standards in Section 17-5-5. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-2 Standards for Storage of Materials and Equipment. A.  The storage or processing of materials is prohibited if they are, in time of flooding: buoyant, flammable, explosive, or could be noxious, deadly, or injurious to human, animal, or plant life. B.  Storage of other material or equipment may be allowed if they are not subject to major damage by floods, or if they are firmly anchored to prevent flotation, or if they are readily removable from the area within the time available after flood warning. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 28 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 17-5-3 Standards for Water Supply and Waste Disposal Systems. A.  All new or replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from systems into floodwaters. B. On-site waste disposal systems shall not be installed wholly or partially in a regulatory floodway, erosion setback, or as established by the Arizona Department of Environmental Quality (ADEQ), whichever is most restrictive. C.  On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-4 Standards and Submittal Requirements for Subdivisions. A.  All new subdivision proposals and other proposed development (including proposals for manufactured home parks and subdivisions), greater than fifty (50) lots or five (5) acres, whichever is the lesser, shall: 1.  Identify the regulatory floodplain area and the elevation of the base flood; and 2.  Identify on the final plans the elevation(s) of the proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and grade elevations shall be certified by an Arizona registered professional engineer or Arizona registered professional land surveyor and provided to the Floodplain Administrator. B.  All subdivision proposals shall be consistent with the need to minimize flood damage. C.  All subdivision proposals (also referred to as a final site plan) shall have all public utilities and facilities, including but not limited to sewer, gas, electrical, and water systems, located and constructed to minimize flood damage. D.  All subdivisions shall provide adequate drainage to reduce exposure to flood hazards (see adopted drainage criteria manual). E.  Suitability of the Land. Land that has been found by the Floodplain Board to be unsuitable for development with permanent structures based on hydrological and engineering studies of flooding can be platted and used only for open space and greenbelt uses such as those identified in Section 17-5-7(B)(1). This includes land which is: 1.  Physically unsuitable because of flooding, poor drainage, and other features which may endanger health, life, or property, aggravate erosion, increase the flood hazard, or increase the burden imposed on the community, its governmental units, and its citizens; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 29 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 2.  Subject to flooding because of its proximity to the stream or watercourse; or because of low elevation. In applying this provision, the Floodplain Board, with technical support and recommendations from the Town Engineer, shall consider: a.  Land subject to flooding by the base flood shall not be platted for residential occupancy, or building sites, or for any other uses that may increase the flood hazard or endanger health, life, or property, unless each lot contains a building site that meets requirements set forth below, in subsections (G) and (H) of this section, and within other pertinent sections of this chapter; b.  Fill shall not be used to raise land within the regulatory floodway. In other areas subject to flooding by the base flood, fill may be used; provided, that the proposed fill does not restrict the flow of water and increase flood heights or velocities in the regulatory floodway, according to the same standards established in Section 17-5-8; and provided, that compensatory flood storage is provided. F.  Flood Situation to Be Shown on Plat. Plats submitted shall show the following: 1.  Conceptual site development plans (plats) shall show the location, by survey, of watercourses, channels, irrigation laterals, private ditches, culverts, lakes, or other water features, including direction of flow, water level elevations, and the location and extent of areas subject to frequent inundation; 2.  All preliminary subdivision proposals shall identify the special flood hazard areas, regulatory floodplain, the elevation of the base flood, pre- and post-development water surface elevations, and pre- and post-development floodplain limits; 3.  All conceptual and final subdivision plans will provide the elevation(s) of proposed structure(s) and pads. If the site is filled above the base flood elevation, the final lowest floor and pad elevation shall be certified by an Arizona registered professional engineer or an Arizona registered professional land surveyor and provided to the Floodplain Administrator and the Town Building Official; 4.  Final plats shall show the limits of the regulatory floodplain and the regulatory floodway, as well as the corresponding one hundred (100) year flood peaks, and their contributing drainage areas, entering and exiting the development; 5.  Conceptual and final site plans shall show proposed improvements for areas subject to flooding and/or for areas which contain extremely poor drainage facilities such that the proposed improvements make the areas safe from flooding for the respective type of occupancy. G.  Street Elevations. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 30 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 1.  Refer to the Town’s adopted drainage criteria manual and subdivision street standards for additional information and requirements. 2.  Fill used for the streets in areas subject to flooding shall not increase flood heights more than a designated amount as defined in Section 17-5-8(A)(1)(b). 3.  The developer shall provide pre- and post-developed water surface elevation for streets proposed for placement in or adjacent to areas subject to flooding. Headwater ponding limits and water surface elevations shall be shown upstream of all culvert crossings. H.  Building Site. 1.  Residential lots shall contain a building site, either natural or manmade, which is not subject to flooding by the base flood. 2.  In areas subject to flooding by the base flood, where no fill is proposed, the building line shall be located no closer to the watercourse or channel than the edge of the area subject to flooding by the base flood. In areas where fill is used to raise the elevation of the building site, no fill shall be placed in the regulatory floodway. Further, where fill is used, the erosion setback shall not be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for protected banks. I.  Setback from Channels. Along reaches of all regulated watercourses, erosion setback requirements from banks of washes shall be established in accordance with the Town’s adopted drainage criteria manual or standards accepted by the Town Engineer. J.  Easements for Drainage. Whenever any watercourse is located in the area being subdivided, an easement or common area encompassing each side of the watercourse shall be provided for the purpose of protecting and/or maintaining the watercourse for flood and drainage purposes, and such further width for construction of bank protection, physical access for maintenance, or for allowing for natural meander of the stream or watercourse that may be reasonably expected, or for all these as will be adequate for the purpose, as determined by the Town Engineer. K.  Detention/Retention Systems. See Town’s adopted drainage criteria manual for requirements pertaining to detention/retention systems by visiting the administrative offices of the Town of Oro Valley. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-5 Standards for Manufactured Homes. All manufactured homes that are placed within or substantially improved while located within a regulatory floodplain shall apply for and obtain a floodplain use permit summarizing site conditions including base flood elevation, depth of the base flood, and minimum prudent erosion setback. The application for a floodplain use permit shall be accompanied by a site plan, prepared by an Arizona Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 31 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. registered engineer, that conforms to the State of Arizona Office of Manufactured Housing, “Minimum Standards for Manufactured Housing Foundations in Floodplains,” dated October 14, 2009, or as subsequently amended. Accessory structures attached to a manufactured home must meet the provisions of this chapter unless its uses are limited to parking of vehicles or storage. Furthermore, manufactured homes shall: A. Be elevated so that the lowest structural member or the lowest point of any attached appliances, whichever is lower, is at or above the regulatory flood elevation. B.  Be securely anchored to an adequately anchored foundation system to resist flotation, collapse, or lateral movement. This anchoring requirement is in addition to applicable State and local anchoring requirements for resisting wind forces; and C.  Upon completion of installation of the manufactured home, certification by an Arizona registered professional engineer or Arizona registered professional land surveyor that the elevation requirements of this section have been satisfied shall be provided to the Floodplain Administrator for verification. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-6 Standards for Recreational Vehicles. All recreational vehicles placed within a regulatory floodplain area will either: A.  Be on site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use, to the extent that they are not prohibited by any other ordinance. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions; or B.  Meet the permit requirements of Article 17-4, and the elevation and anchoring requirements for manufactured homes in Section 17-5-5. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-5-7 Floodways. Located within regulatory floodplain areas, established in Section 17-3-2, are areas designated as regulatory floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris, potential projectiles, and increase erosion potential, the following provisions apply: A.  Encroachments, including fill, new construction, substantial improvements, and other development are prohibited in floodways. The Floodplain Administrator will consider encroachments where certification by an Arizona registered professional engineer is provided demonstrating that Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 32 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. encroachments will result in no increase whatsoever in flood levels during the occurrence of the base flood discharge, and that the encroachment will not pose a threat to life or property. B.  Floodway Requirements. 1.  Uses Permitted. The following open space uses shall be permitted to the extent that they are not prohibited by any other ordinance or State or Federal permit requirements, nor conflict with uses permitted in adjoining zones, and provided they do not require structures, fill, or storage of materials or equipment: a.  Agricultural uses, including general farming, pasture, grazing or outdoor plant nurseries, horticulture, viticulture, truck farming, sod farming, wild crop harvesting, and restoration of native vegetation; b.  Private and public recreational uses; c.  Accessory residential uses, including lawns, gardens, and play areas. C.  Limitations. 1.  No use shall be allowed within a regulatory floodway which: a.  Acting alone or in combination with existing or future uses creates a danger or hazard to life or property; b.  Increases the water surface elevation of the base flood; or c.  Adversely affects groundwater recharge. D.  If this section is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions in this article. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-5-8 Floodway Fringe Area Requirements. A.  Floodway fringe areas shall be subject to the following regulations: 1.  The following uses shall be permitted within a floodway fringe area to the extent that they are not prohibited by any other ordinance, and only upon issuance of a floodplain use permit: a.  Any use permitted in Section 17-5-7, Floodways; b.  Any other use not involving structures, provided it is elevated above the regulatory base flood elevation and a determination is made by the Town Engineer that the use will not increase the base flood elevation more than one (1) foot where the owner of the land doing Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 33 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. the development owns both sides of the floodway, and not more than one-tenth (0.1) foot where only one (1) side is owned. In no case shall the development increase the water surface elevation more than one-tenth (0.1) foot on the property owned by others upstream and downstream, nor unduly restrict the capacity of the channels or floodway of tributaries to the main stream or watercourse, drainage ditches, or other drainage facilities or systems. The aforementioned water surface elevation increases apply to all watercourse channels in Oro Valley except the Canada del Oro Wash where the elevation of the existing levee system and bank protection will allow for no water surface elevation increases due to encroachment. Additionally, when main channel floodflow velocities are greater than four (4) feet per second (fps), a land use/development activity shall not increase floodflow velocities immediately downstream of the activity by more than one (1) fps or ten percent (10%), whichever is less, in the regulatory floodway. Any velocity increase greater than the aforementioned criteria must be reviewed and approved by the Town Engineer; c.  Structures, including dwellings, may be erected or moved, provided the lowest floor or basement floor is placed at or above the regulatory flood elevation. Land may be filled; provided, that the top of such fill shall be at or above the regulatory flood elevation for the particular area, and unless structurally protected from erosion shall extend at such elevations at least twenty-five (25) feet beyond the limits of any structure erected or placed thereon. Where structural protection from erosion is provided, the minimum extent to which tops of the fill pad must extend shall not be less than fifteen (15) feet. The placement of structures and any accompanying fill shall not affect base flood elevation beyond the limits set in subsection (A)(1)(b) of this section. B.  The following minimum requirements apply to all uses located within a regulatory floodplain: 1.  All new construction (including prefabricated structures and mobile homes) and substantial improvements shall be anchored to prevent flotation and lateral movement, and be constructed with flood resistant materials and methods. 2.  All proposed plats and proposals for other developments, including their utilities, streets, and drainage structures, shall be located and designed to be consistent with the need to minimize flood damage. 3.  All tentative development plans, site plans, final site plans, improvement plans, and final plats, and other proposed new developments shall include base flood elevation data or as otherwise directed by the Town Engineer. 4.  If in a riverine situation, all adjacent communities and the State Coordinating Office must be notified prior to any alteration or relocation of the watercourse, and copies of such notifications must be sent to the FEMA. Within the proposed altered or relocated portion of any watercourse, the flood carrying capacity shall be maintained. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 34 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 5.  Within one hundred twenty (120) days after completion of construction of any flood control protective works which changes the rate of flow during the flood, or changes the configuration of the floodplain, the person or agency responsible for installation of the protective works shall provide to the governing bodies of all jurisdictions affected by the protective works a new delineation of all floodplains affected. The new floodplain delineation shall be done according to the criteria adopted by the State of Arizona Director of Water Resources. C.  Limitations. 1.  No use shall be allowed within a floodway fringe which: a.  Acting alone or in combination with existing or future uses creates danger or hazard to life or property; b.  Increases the water surface elevation for the base flood by more than that allowed under subsection (A)(1)(b) of this section; c.  Adversely affects groundwater recharge. D.  Critical Facilities. 1.  “Critical facility” means any of the following: a.  A structure or facility that produces, uses or stores highly volatile, flammable, explosive, toxic, and/or water-reactive materials; b.  Hospitals, emergency medical facilities, nursing homes and/or housing facilities likely to have occupants who may not be sufficiently mobile to avoid injury or death during a flood; c.  Essential emergency response facilities, such as police stations, fire stations, emergency shelters and/or operation centers that are needed for public safety and/or flood response activities before, during and after a flood; and d.  Public and private utility facilities, such as but not limited to power, water and wastewater treatment, and/or communications, that are vital to maintaining or restoring normal services to flooded areas before, during and after a flood. 2.  Applicability. The critical facility requirements shall only apply along watercourses which have FEMA designated floodplains. Where the two-tenths percent (0.2%) chance floodplain has not been established, the Town Engineer may require that this floodplain be delineated by the applicant. 3.  Critical facilities shall be located outside of the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, if possible. If a critical facility must be located in a two- tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, it must be Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 35 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. demonstrated that there is either a critical need to locate it within the floodplain, or that there is not a suitable alternative site, as justified by an Arizona registered professional engineer. Any critical facility located within a two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain shall be protected from that event. “Protection” includes, but is not limited to, elevating the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all weather access during the base flood and developing an emergency response plan. 4.  Existing critical facilities within the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain that propose substantial improvements and/or repairs shall be protected from the two-tenths percent (0.2%) annual chance (five hundred (500) year) flood event. “Protection” includes, but is not limited to, elevating or flood-proofing the lowest floor and all utilities and mechanical services to a minimum of one (1) foot above the base flood or to the two -tenths percent (0.2%) annual chance (five hundred (500) year) floodplain water surface elevation, whichever is greater, providing elevated access ramps, if appropriate, adequately protecting the facility from both lateral and vertical erosion associated with the two-tenths percent (0.2%) annual chance (five hundred (500) year) floodplain, providing all-weather access to the base flood and developing an emergency response plan. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) 17-5-9 Flood-Related Erosion-Prone Area. The protection of Town residents and their property from injury and damage that can occur as a result of streambank lateral migration due to erosion and scour is of primary importance in the administration of this chapter and the following criteria apply: A.  The Floodplain Administrator shall require Floodplain Use Permits for proposed construction and other development within all flood-related erosion-prone areas, as determined by lateral migration analysis described in the Town’s drainage criteria manual or in other predetermined, documented evidence. Areas generally most susceptible to lateral erosion and scour include, but are not limited to, locations of historical stream/wash meandering, locations where poorly defined or poorly consolidated banks occur, wash reaches characterized by changes in the direction, velocity, or amount of streamflow, and locations in the proximity of stabilizing features or structures such as rock outcrops or bridges. Alternative safe limits for erosion setbacks may be considered if approved in writing by the Floodplain Administrator based on an acceptable engineering study prepared and sealed by an Arizona registered professional engineer. However, at no time shall a setback be less than twenty-five (25) feet from an unprotected bank, and not less than fifteen (15) feet for a protected bank. Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 36 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. B.  Permit applications shall be reviewed to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion, and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard. C.  If a proposed development or structure including associated permanent features such as a patio wall or swimming pool or any other feature is found to be in the path of flood-related erosion, or would increase the erosion hazard, such improvements shall be relocated or adequate protective measures shall be taken to avoid aggravating the existing erosion hazard. D.  Areas within the erosion setback may be used for suitable open space purposes, such as for outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-6 APPEAL AND VARIANCE PROCEDURES Sections: 17-6-1 Nature of Variances 17-6-2 Floodplain Board 17-6-3 Appeals and Request for Variance Considerations 17-6-4 Conditions for Variances 17-6-1 Nature of Variances. The variance criteria set forth in this article are based on the general principle of zoning law that variances pertain to a piece of property and are not personal in nature. A variance may be granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter would create an exceptional hardship to the applicant or the surrounding property owners. The characteristics must be unique to the property and not be shared by adjacent parcels. The unique characteristic must pertain to the land itself, not to the structure, its inhabitants, or the property owners. It is the duty of the Town of Oro Valley to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring a structure built below the regulatory flood elevation are so serious that variances from the regulatory flood elevation shall not be granted. Variances from other requirements in the floodplain management ordinance are quite rare. The long- term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 37 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. screen out those situations in which alternatives other than a variance are more appropriate. ((O)21- 06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-6-2 Floodplain Board. A.  The Floodplain Board of Oro Valley shall hear and decide requests for variances from the requirements of this chapter to FEMA regulated floodplains, as well as hear appeals to decisions from previous determinations or actions on non-FEMA regulated floodplains by the Floodplain Administrator or the Town Engineer. B.  The Floodplain Board shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Floodplain Administrator in the enforcement or administration of this chapter with regard to FEMA regulated floodplains and floodplains identified on the Town’s Flood Insurance Rate Maps. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35, 10/05/2005) 17-6-3 Appeals and Request for Variance Considerations. A.  In considering appeals and requests for variance, the Floodplain Board shall consider all technical evaluations, all relevant factors, and all standards specified in other sections of this chapter, and also consider: 1.  The danger that materials may be swept onto other lands to the injury of others; 2.  The danger of life and property due to flooding or erosion damage; 3.  The susceptibility of the proposed facility and its contents to flood damage, and the effect of such damage on the individual owner; 4.  The importance of the services provided by the proposed facility to the community; 5.  The necessity to the facility of a waterfront location, where applicable; 6.  The availability of alternative locations for the proposed use that are not subject to flooding or erosion damage; 7.  The compatibility of the proposed use with existing and anticipated development; 8.  The relationship of the proposed use to the comprehensive plan and floodplain management program for the area encompassing the proposed use; 9.  The safety of access to the property in time of flood for ordinary and emergency vehicles; Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 38 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 10.  The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and 11.  The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, water system, and streets and bridges. B.  Upon consideration of the factors of subsection (A) of this section and the purposes of this chapter, the Floodplain Board may attach such conditions to the granting of appeals and variances as it deems necessary to further the purposes of this chapter. C.  The Floodplain Administrator shall maintain a record of all variance actions, including justification for their issuance, and shall report any such variances that are issued in FEMA regulated floodplains in its biennial report, which is also submitted to the Federal Emergency Management Agency. D.  Any applicant to whom a variance is granted shall be given written notice over the signature of the Floodplain Administrator, or their designee, that: 1.  The issuance of a variance to construct a structure below the base flood elevation will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage; and 2.  Such construction below the regulatory flood elevation increases risks to life and property; and E.  A person aggrieved in any manner by an action of the Floodplain Board may within thirty (30) days appeal to the Floodplain Board. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) 17-6-4 Conditions for Variances. A.  Variances shall only be issued upon: 1.  A showing of good and sufficient cause; 2.  A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief; 3.  A determination that failure to grant the variance would result in exceptional hardship to the applicant; 4.  A showing that the use cannot perform its intended purpose unless it is located or carried out in close proximity to water. This includes only facilities defined in Article 17-2 in the definition of “functionally dependent use” (which is unlikely due to the Town of Oro Valley’s arid climate); and Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 39 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. 5.  A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances. B.  Variances shall not be issued within any regulatory floodway if any increase in the base flood elevation would result. C.  Variances may be issued for the repair, rehabilitation, or restoration of structures listed in the National Register of Historic Places or the State Inventory of Historic Places upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as a historic structure, and that the variance is the minimum necessary in order to preserve the historic character and design of the structure. D.  The Floodplain Administrator, at his/her discretion, may grant a variance for non-FEMA regulated flood hazard areas. E.  Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (0.5) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the regulatory flood elevation, provided the procedures of Articles 17-4 and 17-5 have been fully considered. As the lot size increases beyond one-half (0.5) acre, the technical justification required for issuing the variance increases. ((O)21-06,  11/17/2021; (O)17- 04,  04/05/2017; (O)05-35,  10/05/2005) Article 17-7 ORDINANCE AMENDMENTS Sections: 17-7-1 Procedures 17-7-1 Procedures. A.  The Floodplain Board may from time to time, after a public hearing required by law (ARS § 38- 431.01, and other open meeting laws), amend, supplement, or change the regulations set forth herein or subsequently established. Any amendment, supplement, or change may be initiated by the Floodplain Board or by petition of affected persons hereafter provided. B.  The procedures established by this article are to provide for appropriate and timely ordinance amendments, with due consideration of the purpose of this article. ((O)21-06,  11/17/2021; (O)17-04, 04/05/2017; (O)05-35,  10/05/2005) Oro Valley Town Code Chapter 17, Floodplain and Erosion Hazard Management Page 40 of 40 The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. Article 17-8 FEES Sections: 17-8-1 Fee Schedule 17-8-1 Fee Schedule. Fees for floodplain use permits will be charged based on the fee schedule approved by the Town Council. ((O)21-06,  11/17/2021; (O)17-04,  04/05/2017; (O)05-35,  10/05/2005) The Oro Valley Town Code is current through Ordinance (O)24-08, passed September 18, 2024. Disclaimer: The Town Clerk’s Office has the official version of the Oro Valley Town Code. Users should contact the Town Clerk’s Office for ordinances passed subsequent to the ordinance cited above. Town Website: www.orovalleyaz.gov Hosted by General Code. Chapter 17 Amendments: Floodplain & Erosion Hazard Management Amendments Town of Oro Valley Stormwater Utility Commission Presenter: Dennis Roberts, Stormwater Utility Division Manager May 21, 2026 Purpose of Agenda Item • Present proposed amendments to Town Code Chapter 17 • Summarize ADWR Community Assistance Visit (CAV) findings • Review how proposed revisions address State and FEMA requirements • Request Commission recommendation to forward amendments to Mayor and Council Background • Chapter 17 was last updated in 2021 • ADWR completed a Community Assistance Visit in January 2023 • CAV identified needed updates to align with: • Arizona Floodplain Management Model Ordinance (June 2023) • Current NFIP requirements • State and federal best practices • Staff incorporated all ADWR recommendations What the CAV Identified ADWR noted the need for: • Updated and clarified definitions • Consistency with State Model Ordinance language • Clearer administrative and permitting procedures • Removal of outdated, conflicting, or unclear sections • Better alignment with FEMA requirements for: • Floodplain use permits • Elevation and certification • Floodway and floodway fringe standards • Variances and appeals Overview of Revisions Revisions include: • Updated definitions throughout Article 17-2 • Clarified procedures for floodplain use permits and map updates • Updated standards for construction, utilities, and subdivisions • Clarified appeal and variance procedures • Cleaned up outdated or redundant text • Improved internal constancy and readability • No new regulatory burdens beyond what ADWR requires What Did NOT Change • No changes to FEMA-mapped floodplains • No new fees or permitting requirements • No expansion of regulatory areas • No changes that affect homeowner insurance requirements • No new enforcement authorities beyond existing State and NFIP rules Why Adoption is Important Adopting the Updates: • Ensures compliance with State law (ARS §48- 3609/3610) • Maintains NFIP good standing • Protects community eligibility for: • Federally backed flood insurance • Post-disaster FEMA assistance • Hazard mitigation grants • Reduces liability exposure for the Town • Demonstrates strong local floodplain management capability Documents Provided to Commission Included in the agenda packet: • ADWR CAV comments summary • Redline version of Chapter 17 • Clean version of Chapter 17 (formatted for adoption) • Staff report and supporting materials Commission is asked to review and provide feedback Next Steps in the Process If supported by the Commission: • Recommendation forwarded to Mayor & Council • Town Legal prepares final ordinance language • Staff schedules item for next available Council Regular Session • Upon Council adoption, Chapter 17 is updated in Town Code • Staff transmits updated ordinance to ADWR and FEMA Questions and Feedback Questions from the Commission • Staff available for clarifications • Feedback will be incorporated into the final package Thank You Town of Oro Valley Stormwater Utility Division Contact: Dennis Roberts, Division Manager Email:droberts@orovalleyaz.gov Phone:520-229-5044