Title
City of Phoenix and Salt River Project Cost Sharing Agreement to Develop Watershed Erosion Model and Simulation for Munds Draw Watershed (Ordinance S-47959)
Description
Request to authorize the City Manager, or his designee, to enter into a cost sharing agreement with the Salt River Valley Water Users' Association and the Salt River Project Agricultural Improvement and Power District to share the costs to develop a Watershed Erosion Model and simulate results using the model for the Munds Draw Watershed to project the effectiveness and benefits of potential erosion control measures to address dam sedimentation. Further request to authorize the City Controller to disburse all funds related to this item. The total cost of this agreement will not exceed $23,760.
Report
Summary
Salt River Project Agricultural Improvement and Power District (SRP) has constructed two dams on the Verde River, known as Bartlett Dam and Horseshoe Dam, which are operated and used by SRP to provide, develop, and distribute the supply of water conserved by the dams to its members. The City, through a series of agreements with SRP and the federal government, funded construction of gates and other facilities in the spillway at Horseshoe Dam which allowed the City to obtain its own distinct storage rights behind Horseshoe Dam. The agreements among SRP, the City and the federal government recognize that sedimentation behind the dams would result in loss of water storage capacity, negatively impacting all. Thus, both SRP and the City have an interest in minimizing erosion in the Verde River Basin that causes sedimentation behind the dams.
Munds Draw Watershed (MDW) is in the Upper Verde River Basin. Recent studies of the MDW classify it as Functioning at Risk, and a goal has been established to move it to Proper Functioning within a six-year time frame. To achieve this objective, the City and SRP wish to share the costs to develop a Watershed Erosion Model (WEM) that can assist in projecting the effectiveness and benefits of potential erosion control measures.
The total cost estimate for the WEM Development and Simulation is approximately $90,000, plus a 10 percent contingency, for a total of $99,000. The City's share of the costs will be proportional to the City's reduced storage capacity behind Horseshoe Dam due to silt sedimentation, as specified by the agreement between the Salt River Valley Water Users' Association and the City of Phoenix dated Nov. 22,1946. That proportion is 24 percent.
Contract Term
The agreement will terminate once the WEM Development and Simulation has been completed, or until total costs meet $99,000, whichever occurs first.
Financial Impact
The value of the City's share of the agreement will not exceed $23,760.
Funding for this agreement is available in the Water Services Department's Capital Improvement Program budget.
Location
Munds Draw Watershed
Council District: Out of City
Department
Responsible Department
This item is submitted by Deputy City Manager Karen Peters and the Water Services Department.