10.A.
City Council Meeting - FINAL
- Meeting Date:
- 07/05/2022
- Co-Submitter:
- Gary Miller
- From:
- Edward Schenk, Water Services Manager - Stormwater
Information
TITLE
Consideration and Adoption: Administrative Floodplain Designation - Spruce Wash
STAFF RECOMMENDED ACTION:
Adopt the proposed Administrative Floodplain of Spruce Wash to help educate current and future residents impacted by post-wildfire flooding and to provide appropriate development standards for new development within the affected area.
EXECUTIVE SUMMARY:
The Stormwater Section is providing City Council with a proposal for an Administrative Floodplain overlay for Spruce Wash between Paradise Road and Route 66. The overlay will be based off of the 2022 existing conditions hydrologic model created by JE Fuller for the County Flood Control District. The overlay will be based on the 3-inch rain event in 45 minutes roughly mirroring a 100-year design storm. The proposed overlay was presented to Water Commission on May 19th 2022 with no objections or questions. Council approval is requested to formally adopt this floodplain overlay by the City for education and development management within the Spruce Wash footprint.
The purpose of the overlay will be to provide guidance for City building permits, development review, floodplain use permits, and private landowners for their individual flood mitigations. The administrative floodplain will be managed by City staff similar to a Federal FEMA floodplain (Zone AE) with the following exceptions:
The 50% development rule for FEMA floodplains will be waived.
Mandatory NFIP flood insurance will be waived (but strongly recommended).
Waivers for new development at 1 foot above BFE will be considered on a case-by-case basis.
The administrative floodplain overlay will be replaced by a formal FEMA CLOMR/LOMR once the watershed has restored or flood mitigation projects are completed. Alternatively, a new overlay may replace this map if future hydrological modeling and mapping are completed by the City or the County to reflect changes in flood risk.
The purpose of the administrative floodplain is two-fold: to provide an education tool for flood risk for both existing and future residents within the affected area and to provide development standards (base flood elevation determination) for new development within the affected area.
The purpose of the overlay will be to provide guidance for City building permits, development review, floodplain use permits, and private landowners for their individual flood mitigations. The administrative floodplain will be managed by City staff similar to a Federal FEMA floodplain (Zone AE) with the following exceptions:
The 50% development rule for FEMA floodplains will be waived.
Mandatory NFIP flood insurance will be waived (but strongly recommended).
Waivers for new development at 1 foot above BFE will be considered on a case-by-case basis.
The administrative floodplain overlay will be replaced by a formal FEMA CLOMR/LOMR once the watershed has restored or flood mitigation projects are completed. Alternatively, a new overlay may replace this map if future hydrological modeling and mapping are completed by the City or the County to reflect changes in flood risk.
The purpose of the administrative floodplain is two-fold: to provide an education tool for flood risk for both existing and future residents within the affected area and to provide development standards (base flood elevation determination) for new development within the affected area.
INFORMATION:
This proposed floodplain overlay supports the following PBB priorities:
High Performance Governance: Implementing innovative local governmental programs and best practices. The Administrative Floodplain concept allows the City to manage with a greater flexibility than a formal FEMA Special Flood Hazard Area while providing many of the same benefits.
Safe and Healthy Community: providing public safety services as well as ensuring the built environment is safe for using through a consistent framework.
Environmental Stewardship: Strengthen Flagstaff's resilience to climate change impacts (and post-fire impacts) on built, natural, economic, health, and social systems through acknowledging the changing flood risk in the Grandview and Sunnyside neighborhoods.
High Performance Governance: Implementing innovative local governmental programs and best practices. The Administrative Floodplain concept allows the City to manage with a greater flexibility than a formal FEMA Special Flood Hazard Area while providing many of the same benefits.
Safe and Healthy Community: providing public safety services as well as ensuring the built environment is safe for using through a consistent framework.
Environmental Stewardship: Strengthen Flagstaff's resilience to climate change impacts (and post-fire impacts) on built, natural, economic, health, and social systems through acknowledging the changing flood risk in the Grandview and Sunnyside neighborhoods.