Overview
Horseshoe Dam, on the Verde River 58 miles northeast of Phoenix, is an earthfill structure 202 feet high, with a reservoir capacity of 131,500 acre-feet. Horseshoe Dam was built from 1944-1946 by the Phelps-Dodge Copper Products Corp. for the Salt River Valley Water Users' Association under a water exchange agreement. Spillway gates were added to the dam in 1949 by the city of Phoenix to increase the domestic water supply. In 1952 the dam was raised 4 feet to elevation 2044.
Horseshoe Dam was alsomodified by Reclamation in 1993 toaddress concerns about its safety in the event of a Probable Maximum Flood or Maximum Credible Earthquake. Modifications included construction of a fuse plug auxiliary spillway with an erodible embankment and a concrete foundation 2,000 feet west of the existing spillway. In addition, a 148,000 cubic-yard stability berm was constructed at the downstream toe of the dam to help stabilize it in the event of an earthquake, and the dam was raised eight feet to enable the spillway to pass the Probable Maximum Flood. To prevent overtopping of the structure from wave action, an additional 4-foot parapet was built on the dam's crest. Other work included modifying the service spillway gates, and construction of an auxiliary spillway, closure dike and training dike.The dam tender facilities were also relocated and the road to the boat ramp upgraded.
General
| Project | Salt River |
| Dam Type | Zoned Rockfill Embankment |
| Location | 58 miles northeast of Phoenix, AZ |
| Longitude | -111.708939 |
| Watercourse | Verde River |
| Reservoir | Horseshoe |
| Original Construction | 1944-1946 |
| National ID Number | AZ10310 |
| Latitude | 33.9834 |
| Modified Construction | 1949, 1952, 1993 |
| Base Width | 619 ft |
Dimensions
| Top Parapet (Elevation) | 2055.0 ft |
| Structural Height | 202.0 ft |
| Crest Length | 1652.0 ft (with spillways 1994 ft) |
| Crest Width | 16.0 ft |
| Top of Active Conservation Pool (Elevation) | 2026.0 ft |
| Volume of Dam Construction Materials | 1,595,780 cu-yds |
| Spillway Crest Elevation | 2000.0 ft |
| Streambed at Dam Axis | 1894.9 ft |
| Crest Elevation | 2052.0 ft |
| Hydraulic Height (Normal Operating Depth at Dam) | 157.0 ft |
| Top of Dead Storage Pool (Elevation) | 1915.0 ft (Tunnel intake elevation) |
Hydraulics & Hydrology
| Spillway Type | Gate concrete ogee crest |
| Auxiliary Spillway | Yes |
| Auxiliary Spillway Capacity at Elevation | 240,000 cfs at 2051.5 ft |
| Total Water Storage at Elevation | 131,500 af at 2026.0 ft |
| Uncontrolled Spillway Capacity at Elevation | 558,000 cfs at 2051.5 ft |
| Outlet Works Capacity at Elevation | 2200.0 cfs at 2026.0 ft |
| Drainage Area | 5630 sq mi |
| Hydrometeorological Report (HMR) | HMR 49 |
| Maximum Water Surface Elevation | 2051.9 ft |
| Normal Water Surface Elevation | 2026 ft |
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