New Don Pedro Dam
| New Don Pedro Dam | |
|---|---|
 USGS image of New Don Pedro Dam |
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| Location | La Grange, California |
| Coordinates | 37°42′02″N 120°25′15″W / 37.70056°N 120.42083°WCoordinates: 37°42′02″N 120°25′15″W / 37.70056°N 120.42083°W |
| Construction began | September 1967 |
| Opening date | 1971 |
| Dam and spillways | |
| Type of dam | Earthen embankment |
| Height | 585 feet (178 m) |
| Length | 1,900 feet (580 m) |
| Base width | 2,800 feet (853 m) |
| Volume | 16,750,000 cubic yards (12,810,000 m3) |
| Impounds | Tuolumne River |
| Type of spillway | Gated overflow |
| Reservoir | |
| Creates | Don Pedro Reservoir |
| Capacity | 2,030,000 acre feet (2.50 km3) |
| Catchment area | 1,542 square miles (3,990 km2) |
| Surface area | 12,960 acres (5,240 ha) |
| Power station | |
| Turbines | 4 Francis type |
| Installed capacity | 203 MW |
| Capacity factor | 34.8% |
| Annual generation | 618.4 million KWh |
New Don Pedro Dam is built across the Tuolumne River and creates Lake Don Pedro in the foothills of the Sierra Nevada mountain range in the U.S. state of California. The New Don Pedro Dam takes its name from Don Pedros Bar which was named after Pierre "Don Pedro" Sainsevain.[1]
Contents |
[edit] History
The dam was built to replace the Old Don Pedro Dam, a concrete arch-gravity structure built in 1924 about a mile (1.6 km) upstream from the modern structure. The reservoir of the old dam held less than fifteen percent of today's capacity, which was barely enough to provide for a single growing season. Construction of the new dam was started in September 1967, the embankment was topped out on May 28, 1970, and the entire project was completed and dedicated on May 22, 1971 at a cost of $105 million. The rising waters of Lake Don Pedro submerged the old dam, which still exists about 250 feet (76 m) below the surface of the reservoir.
[edit] Specifications
The dam is an earth and rock fill type that is 585 feet (178 m) high, 2,800 feet (850 m) thick at the base, and 1,900 feet (580 m) long. The dam contains 16,750,000 cubic yards (12,800,000 m³) of material, much of which came from gold dredge tailings in the Tuolumne River bed downstream near La Grange. While the Turlock Irrigation District (TID) operates the powerhouse at the dam's base, the Modesto Irrigation District (MID) owns 31.54% of the plant and so is entitled to about 63 megawatts of the 203 MW produced by the four generators. Behind Don Pedro Dam is Lake Don Pedro, also called Don Pedro Reservoir, which holds up to 2,030,000 acre feet (2.50 km3) of water, making it the 6th largest body of water in California.
[edit] Water allocation
Water leaving the dam's powerhouse flows about 2.5 miles (4 km) downstream to the La Grange Dam where about 885,000 acre feet (1.092×109 m3) of water is released into two canals. About 575,000 acre feet (709,000,000 m3) goes through TID's canal to Turlock Lake and another 310,000 acre feet (380,000,000 m3) goes through MID's canal to Modesto Reservoir. Nearly all of this water irrigates crops in the Turlock and Modesto Irrigation Districts. Another 230,000 acre feet (280,000,000 m3) goes to San Francisco's Hetch Hetchy Water and Power. And, finally, about 780,000 acre feet (960,000,000 m3) of water is delivered to the Tuolumne River channel to maintain flows in the 52 miles (84 km) of the Lower Tuolumne River through its confluence with the San Joaquin River and then into the Sacramento-San Joaquin Delta.
[edit] References
- ^ Who was Don Pedro? Don Pedro Recreation Agency
[edit] Bibliography
- Turlock Irrigation District
- Modesto Irrigation District
- SFPUC: Hetch Hetchy Water and Power
- USGS Hydrologic Data
- "Lessons from Hetch Hetchy" by Richard W. Amero
- UC Davis Civil Engineering Class Project
