LOCATION AND DESCRIPTION:
Located 50 miles SE of Phoenix, AZ, in Pima County, AZ. Project elements being operated and maintained: Dam (earth-fill; 25-feet-high; 978-feet-long); Outlet Works (circular conduit); and Un-gated Service Roads Reservoir (35,593 acre-foot cap spillway crest - 1976). There are no recreation facilities.
AUTHORIZATION: Flood Control Act of 1946
ACTIVITIES FOR FY 2023: Funds will be used for Operations and Maintenance project and program management, real estate land management, water control & quality management, environmental management & compliance, dam safety, dam maintenance, and resolving our encroachment into Arizona State Land Trust Lands. Additional funding could be used to repair the low spot on the saddle dike, pave the road to the inlet works, conduct a boundary survey, law enforcement contract, develop an operations management plan, and develop a signage program.
FY 2024 Planned Accomplishments: Optimal funding could be used for legal or policy mandated minimum level operational and maintenance activities; water control and management, including data analysis; inspection of land for hazardous materials; environmental stewardship activities and recreation management; developing a signage program; developing and implementing a law enforcement contract with local authorities; develop an operations management plan; conducting a boundary survey; raising the crest of the saddle dike back to design elevation; dam safety oversight; paving the road to the inlet works; and water instrumentation maintenance.
ISSUES AND OTHER INFORMATION: The structure is ungated and requires routine maintenance to manage the sediment and debris, which settles at the outlet works. Since the construction of the Dam in 1960, Phoenix and the surrounding area have experienced a major population increase, with development pushing further into the desert near the ungated flood control structure. A Spillway Erodibility Study started in FY99, and completed in early FY00, concluded that the entire spillway is generally erodible; however, the duration of the expected maximum flow event is so short that a sill breach probably would not occur. Local residents frequently use the Dam structure for target practice with large-bore weapons and rifles. Our Security Officer is working with the local law enforcement to curtail these activities. An operations management plan for the riparian ecosystem must be completed due to the population of southwestern willow flycatcher found in the riparian areas adjacent to the dam structure. The plan would allow for continued operation and maintenance activities without the need for repeat consultations with the USFWS under the ESA.
FINANCIAL SUMMARY:
As of 01 MAR 23
O&M
Estimated Federal Cost $ 1,138,250
Estimated Non-Federal Cost 0
Total Estimated Project Cost $ 1,138,250
Allocation thru FY22 $ 440,550
President’s Budget for FY23 $ 668,250 1/
Workplan for FY23 $ 470,000
President's Budget for FY24 $1,318,680 2/
Workplan for FY24 TBD
Balance to Complete After FY24 N/A
1/ Decreased 1% from $ 675,000
2/ Decreased 1% from $1,332,000
CONGRESSIONAL INTEREST: Senators Kelly and Sinema, Representative Crane (AZ-02)
U.S. ARMY CORPS OF ENGINEERS – LOS ANGELES DISTRICT
915 WILSHIRE BLVD., SUITE 1109, LOS ANGELES, CA 90017
http://www.spl.usace.army.mil