| Monticello Dam | |
|---|---|
| Location | Napa County, California, U.S. |
| Construction began | 1953 |
| Opening date | 1957 |
| Dam and spillways | |
| Height | 304 ft (93 m) |
| Length | 1,023 ft (312 m) |
| Base width | 100 ft (30 m) |
| Impounds | Putah Creek |
| Reservoir | |
| Creates | Lake Berryessa |
| Capacity | 1,602,000 acre·ft (1.976×109 m3) |
| Catchment area | 566 sq mi (1,470 km2)[1] |
| Surface area | 20,700 acres (8,400 ha) |
| U.S. Geological Survey Geographic Names Information System: Monticello Dam | |
Monticello Dam is a dam in Napa County, California, United States constructed between 1953 and 1957. It is a medium concrete-arch dam with a structural height of 304 ft (93 m) and a crest length of 1,023 ft (312 m). It contains 326,000 cubic yards (249,000 m³) of concrete. The dam impounded Putah Creek to cover the former town of Monticello and flood Berryessa Valley to create Lake Berryessa, then the second-largest man-made lake in California. The capacity of the reservoir is 1,602,000 acre·ft (1.976×109 m3).[1] Water from the reservoir primarily supplies agriculture in surrounding areas. The dam is noted for its classic, uncontrolled morning-glory type spillway.[1] The diameter at the lip is 72 ft (22 m). Locally, the spillway is also known as 'The Glory Hole'. [2]
The Monticello Dam Powerplant was built at the dam in 1983 and has three generators. The electrical power is sent mostly to the North Bay area of San Francisco.