Oroville Dam – Tallest Dam in the USA

Oroville Dam

The United States is home to many large and amazing dams. One such dam is the Oroville Dam. Moreover, it is the tallest dam in America with a height of 770 feet. The construction of the Oroville Dam started in 1961, and it was opened on May 4, 1968. It is an earth-fill embankment dam constructed in the Feather River in the Oroville City of California. The dam has created the Oroville Lake which is the second-largest water reservoir in the state of California. The lake can hold about 3.5 million acre-feet of water.

The dam was constructed by the California Department of Water Resources under the California State Water Project. The Oroville Dam is used for hydroelectricity, flood control, water supply, and Feather River fish hatchery.

The Edward Hyatt Power Plant was constructed underground and completed shortly after the Oroville Dam was completed. This hydroelectric power plant generated 819 megawatts of electricity which made it the largest underground power plant at that time. This along with the Thermalito reservoir produces about 2,200 gigawatt hours of electricity per year.

Another reason for which the Oroville Dam was constructed was to supply fresh drinking water in the semi-arid California state. After the Feather River joins the Sacramento River before it goes into the delta a California aqueduct diverts fresh water. This aqueduct is used to supply fresh drinking water to San Joaquin Valley and South California. The water from his dam is used for irrigation of 755,000 acres of land.

The Oroville Dam, like other dams, also helps in flood control. During the early winter when storms are very frequent the dam makes one-fifth of its capacity available for flood control. During such times the dam releases 150,000 cubic feet per second to control any major flooding. During the 1997 flood, it was the dam because of which a large area of the Sacramento Valley was saved from flooding.

The Feather River was a migration route for Chinook salmon and steelhead trout. However, the construction of the dam disrupted this route. So, in 1967, the DWR and the California Department of Fish and Games built the Feather River fish hatchery. When the fishes reach the Thermalito diversion dam they are made to move upward to the hatchery. Every year this hatchery produces 10 million salmon and 450,000 trout.

The Oroville Dam has been a very safe and reliable dam however it also has a fair share of up and down as well. In 2009, there was a river valve accident which almost took the lives of 3 workers. This happened when they were deep below the operating flow control.

In 2020, a safety assessment was done by the DWR which concluded that the Oroville Dam was safe and safe for operations.