Smith Mountain Dam facts for kids
Quick facts for kids Smith Mountain Dam |
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USGS image of the Smith Mountain Dam
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| Location | Bedford / Pittsylvania counties, Virginia, USA |
| Coordinates | 37°02′28″N 79°32′08″W / 37.04111°N 79.53556°W |
| Construction began | 1960 |
| Opening date | 1963 |
| Construction cost | USD $103 million (hydro-power units) |
| Operator(s) | Appalachian Power (American Electric Power) |
| Dam and spillways | |
| Type of dam | Concrete arch |
| Impounds | Roanoke River, Blackwater River |
| Height | 235 ft (72 m) |
| Length | 816 ft (249 m) |
| Width (base) | 30 ft (9.1 m) |
| Reservoir | |
| Creates | Smith Mountain Lake |
| Total capacity | 2.8 km3 (0.67 cu mi) |
| Surface area | 32 sq mi (83 km2) |
| Power station | |
| Commission date | 1965-1980 |
| Turbines | 2 x 70 MW (94,000 hp) 2 x 160 MW (210,000 hp) Francis-type 1 x 100 MW (130,000 hp) reversible Francis-type |
| Installed capacity | 560 MW (750,000 hp) |
Smith Mountain Dam is a huge wall built across the Roanoke River in Virginia. It's a special type of dam called a concrete arch dam. This amazing structure created a giant lake behind it, known as Smith Mountain Lake. The dam was built by a company called Appalachian Power between 1960 and 1963. Its main job is to make electricity using a cool method called pumped-storage hydroelectricity. Smith Mountain Lake has also become a very popular spot for fun activities like boating and swimming, and many homes have been built around its shores.
Contents
Building the Dam
Early Plans and Construction Start
Back in the late 1920s, Appalachian Power started buying land. They planned to build a dam for hydroelectricity in the Smith Mountain Gorge. This gorge is a deep valley cut by the Roanoke River.
After some delays and important engineering studies, construction finally began in 1960. At the same time, work also started on a smaller dam. This dam, called Leesville Dam, was built further downstream.
Building the Walls and Roads
Workers began pouring concrete for the dam in 1961. By 1962, all the roads and bridges that would be covered by the new lake were rebuilt. This made sure people could still get around.
Filling the Lake and Adding Generators
The process of filling the reservoir, Smith Mountain Lake, started on September 24, 1963. It took some time for the lake to reach its full size.
In 1964, the first four hydro-electrical generators were put in place. These machines are key to making electricity from the water.
In 1965, special underwater divers helped fix some parts of the dam. They replaced faulty "trash racks" that were 200 feet deep.
On March 7, 1966, the lake was completely full. Later, in 1979, a fifth hydro-electrical generator was added. This increased the dam's power to 560 megawatts (MW).
How the Dam Makes Electricity
Pumped-Storage Hydroelectricity Explained
Smith Mountain Dam has five hydroelectric generators. Together, they can produce 560 MW of power. This dam uses a clever system called pumped-storage hydroelectricity.
Here's how it works:
- Water flows from Smith Mountain Lake through the dam to make electricity.
- This water then goes into a smaller lake, Leesville Lake, which is downstream.
- During times when people don't need much electricity (like at night), the water from Leesville Lake is pumped back up into Smith Mountain Lake.
- This way, the water can be used again to make more electricity when demand is high (like during the day).
The Leesville Dam helps control the water flow from Smith Mountain Lake. It also makes its own electricity.
Operating the Power Plant
In December 2009, the U.S. Federal Energy Regulatory Commission gave Appalachian Power a new license. This license allows them to keep running the hydroelectric plant for another 30 years. The new license also includes plans for managing recreation and protecting the environment around the lake.
