Title
Request Authorization to Enter Into an Intergovernmental Agreement with Flood Control District of Maricopa County and the City of Scottsdale for the Rawhide Wash Project (Ordinance S-45224)
Description
Request to authorize the City Manager, or his designee, to enter into an Intergovernmental Agreement (IGA) with the Flood Control District of Maricopa County (FCDMC) and the City of Scottsdale for the Rawhide Wash Project. Further request authorization for the City Treasurer to accept and the City Controller to disburse all funds related to this item. The estimated project cost for the design phase is estimated at $2 million of which the City's cost share is estimated to be $800,000. The design phase will include final design, channel rights-of-way, and utility relocations.
Report
Summary
The Rawhide Wash Flood Hazard Mitigation project is defined as the conveyance alternative presented in the Pinnacle Peak West Area Drainage Master Study. The northern limit of the infrastructure is approximately the Rawhide Wash alluvial fan apex located north of Happy Valley Road and the southern limit is the bridge crossing at Pinnacle Peak Road east of Scottsdale Road. The project improvements will include construction of new floodwalls and levees and re-construction of existing floodwalls and levees. The project will also include submittal of an application for a Federal Emergency Management Agency (FEMA) Letter of Map Revision to revise the apex flow discharge and the re-delineation of the floodplain limits downstream of Scottsdale Road within City of Phoenix jurisdiction upon completion of this construction project. Floodplain re-delineation within City of Phoenix jurisdiction will be based on existing condition drainage infrastructure, development activities, and topography that will reduce the existing Special Flood Hazard Area Zone "AO." After completion of the proposed project, approximately 1,531 acres of land within Phoenix jurisdiction will no longer be designated in a FEMA delineated floodplain, which benefits approximately 80 percent from a total of approximately 1,933 acres of land. The remaining 20 percent, or approximately 402 acres, are within the City of Scottsdale and unincorporated County areas. The cost share analysis was developed based on flood damage reduction, flood insurance savings, reduced cost of fill for future development and the elimination of redundant infrastructure costs. This resulted in a cost share of 50 percent FCDMC, 40 percent City of Phoenix, and 10 percent City of Scottsdale.
During the design phase, an amendment to this Intergovernmental Agreement will be developed and processed for the construction phase of the project. A separate request for construction phase funding for the project will be submitted for City Council consideration.
Financial Impact
The estimated project design cost is $2 million. Of this amount, the City's cost share is estimated to be $800,000, with the remainder covered by FCDMC and the City of Scottsdale. Funds are available in the Street Transportation Department's Capital Improvement Program budget.
Concurrence/Previous Council Action
On July 6, 2017, Council approved the request to apply for FCDMC funds for Flood Control Projects under the Capital Improvement Project Prioritization Process (CIPPP). The Rawhide Wash Project was submitted and approved by the FCDMC on Oct. 25, 2017, for FY 2018-19.
This item was recommended for approval by the Water, Wastewater, Infrastructure and Sustainability Subcommittee meeting on Nov. 7, 2018, by a vote of 4-0.
Location
The northern limit of the Project is generally the Rawhide Wash alluvial fan apex located north of Happy Valley Road and the southern limit is the bridge crossing at Pinnacle Peak Road.
Council District: 2 and Outside of City
Department
Responsible Department
This item is submitted by Deputy City Managers Karen Peters and Mario Paniagua, and the Street Transportation and Public Works departments.