Lower Monumental Dam facts for kids
Quick facts for kids Lower Monumental Dam |
|
|---|---|
 |
|
| Location | Franklin and Walla Walla counties, Washington, U.S. |
| Coordinates | 46°33′47″N 118°32′20″W / 46.563°N 118.539°W |
| Construction began | June 1961 |
| Opening date | 1969 |
| Operator(s) | U.S. Army Corps of Engineers |
| Dam and spillways | |
| Type of dam | Concrete gravity, run-of-the-river |
| Impounds | Snake River |
| Height | 100 feet (30 m) |
| Length | 3,791 feet (1,155 m) |
| Spillway type | Service, gate-controlled |
| Reservoir | |
| Creates | Lake Herbert G. West |
| Total capacity | 432,000 acre⋅ft (0.53 km3) |
| Surface area | 6,590 acres (26.7 km2) |
| Normal elevation | 540 ft (165 m) |
| Power station | |
| Turbines | 6 x 135-153 MW |
| Installed capacity | 810 MW 932 MW (max) |
The Lower Monumental Lock and Dam is a huge structure on the Snake River in the Pacific Northwest of the United States. It's a special type of dam that helps make electricity from water power. This is called hydroelectric power.
The dam is also a "run-of-the-river" dam. This means it uses the natural flow of the river to create power, rather than storing a lot of water. It connects Franklin and Walla Walla counties in southeast Washington. You can find it about 6 miles south of Kahlotus. It is also about 43 miles north of Walla Walla.
Building a Giant: How the Dam Was Made
Building the Lower Monumental Dam started in June 1961. The main parts of the dam and its first three power generators were finished in 1969. Later, three more generators were added in 1981.
The dam can produce 810 megawatts of electricity. It can even go up to 932 megawatts when needed. The dam also has a special section called a spillway. This spillway is 572 feet long and has eight gates. These gates control how much water flows through the dam.
The Lower Monumental Dam is an important part of the larger Columbia River Basin system of dams.
What Does the Dam Do?
Behind the dam, there is a large lake called Lake Herbert G. West. This lake is the reservoir for the dam. It stretches about 28 miles east, all the way to the Little Goose Dam.
Downstream from the Lower Monumental Dam, another lake begins. This is Lake Sacajawea, which was formed by the Ice Harbor Dam. Lake Sacajawea extends about 22 miles southwest from the dam.
One of the key features of the Lower Monumental Dam is its navigation lock. This lock helps boats and barges move past the dam. It allows them to travel between the different water levels of the river.
The navigation lock is a "single-lift" lock. This means it raises or lowers boats in one step. The lock is 86 feet wide and 666 feet long. It's big enough for many different types of river vessels.
