| Seven Oaks Dam | |
|---|---|
View of the Seven Oaks Dam, looking northeast up the Santa Ana River. |
|
| Country | United States |
| Location | San Bernardino County, California |
| Coordinates | |
| Construction began | 1994 |
| Opening date | 1999 |
| Construction cost | $250 million |
| Dam and spillways | |
| Type of dam | Earthfill |
| Height | 650 feet (200 m) |
| Length | 2,760 feet (840 m) |
| Crest width | 40 feet (12 m) |
| Base width | 2,200 feet (670 m) |
| Volume | 38,373,000 cubic yards (29,338,000 m3) |
| Impounds | Santa Ana River |
| Type of spillway | Unlined, uncontrolled overflow |
| Spillway capacity | 169,000 cubic feet per second (4,800 m3/s) |
| Reservoir | |
| Creates | Seven Oaks Reservoir |
| Capacity | 147,970 acre feet (182,520,000 m3) |
| Catchment area | 209 square miles (540 km2) |
| Surface area | 780 acres (320 ha) |
| Max. water depth | 550 feet (170 m) |
| Power station | |
| Installed capacity | None |
The Seven Oaks Dam is located on the Santa Ana River, 4 miles (6 km) northeast of Redlands, California. It was constructed by the United States Army Corps of Engineers as a flood control dam. The dam sits virtually on top of the San Andreas Fault and is designed to withstand a magnitude 8.0 earthquake.
Construction of the Seven Oaks Dam began in August 1994. When it was completed, the height of the dam was 550 ft (168 m) and was over 2,200 ft (670 m) wide at its base; 43,000,000 yd³ (33,000,000 m³) of earth and rock were required to build it. It cost $250 million to construct and at the time of its completion in November 1999, and ranked as the 10th largest earthfill dam in the United States.[1] Testing of the dam's high-pressure releases was finally accomplished in early 2011 after years of repairs, mishaps and drought.[2]
The Seven Oaks Dam forms Seven Oaks Reservoir, which has a capacity of 147,970 acre feet (182,520,000 m3). The reservoir is used almost exclusively for flood control, and thus it is usually at a low level or completely dry. It has not yet reached capacity since the dam's construction; the highest water recorded was in March 2005, about 45,000 acre·ft (56,000,000 m3) or 30% of full pool. Controlled release of winter floodwaters from the dam also helps to recharge groundwater in the San Bernardino area.