The Don Pedro Dam, since 1971 also known as the Old Don Pedro Dam, was a dam across the Tuolumne River in Tuolumne County, California. The structure still exists and is flooded underneath Don Pedro Reservoir, which is formed by the New Don Pedro Dam.
| Don Pedro Dam | |
|---|---|
 Old Don Pedro Dam and reservoir, circa 1925 | |
| Official name | Old Don Pedro Dam |
| Location | Tuolumne County, California |
| Coordinates | 37°42′45″N 120°24′07″W / 37.7125°N 120.4020°W |
| Opening date | 1924 |
| Dam and spillways | |
| Type of dam | Concrete thick arch/gravity |
| Impounds | Tuolumne River |
| Height | 283 ft (86 m) |
| Length | 1,000 ft (300 m) |
| Width (crest) | 16 ft (4.9 m) |
| Width (base) | 170 ft (52 m) |
| Reservoir | |
| Creates | Don Pedro Reservoir |
| Total capacity | 290,400 acre⋅ft (358,200,000 m3) |
| Power Station | |
| Turbines | 4 |
| Installed capacity | 30 MW |
Construction
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It was a solid concrete gravity dam that was 283 ft (86 m) high, 1,000 ft (300 m) wide, 16 ft (4.9 m) thick at the crest, and 170 ft (52 m) thick at the base. It was completed in 1923 where the Tuolumne River had carved a narrow gorge with walls of solid rock about a mile (2 km) below Don Pedro Bar. The reservoir created by this dam contained 290,400 acre⋅ft (358,200,000 m3) of water when full, 14.3% of today's capacity.
A 15 megawatt power plant was part of the dam's original design, and two more 7500 kilowatt generators were added in 1926 for 30 megawatts total, just 15% of today's capacity. The old dam still exists about 1.5 mi (2.4 km) upstream from the new 1971 dam, and since the old dam topped out at just 580 ft (180 m) above sea level it is now under some 250 ft (76 m) of water when the new reservoir is full.
References
edit- Dwight H. Barnes. "Chapter 12: The First Don Pedro". The Greening of Paradise Valley, The First 100 Years of the Modesto Irrigation District. Modesto Irrigation District. Retrieved November 7, 2010.
- Richard W. Amero (June 30, 2000). "Lessons from Hetch Hetchy". Retrieved November 7, 2010.
{{cite journal}}: Cite journal requires|journal=(help) - Sukhwant Virk; Josh Hinkey (August 31, 2007). "Don Pedro Dam: General Information". University of California, Davis. Archived from the original on June 10, 2010. Retrieved November 7, 2010.
- Department of Water Resources (2009). "Station Meta Data: Don Pedro Reservoir (DNP)". California Data Exchange Center. State of California. Archived from the original on November 16, 2010. Retrieved November 7, 2010.
