A dam is an artificial barrier constructed on a river or a stream for different purposes. Dam construction goes back thousands of years, with ancient civilizations such as Mesopotamia building dams for irrigation purposes. While dam construction has a long history, it was until the industrial revolution that dams were constructed on large scale never seen before. The United States is home to some of the tallest dams in the world.

Tallest Dams in the United States

Oroville Dam

Oroville Dam is a large dam situated on the Feather River near Oroville, California. It is the US’s tallest dam covering a height of 770 feet and is among the longest in the country, spanning 6,920 feet long. The dam serves several purposes which include generation of hydroelectric power, controlling of the water levels on Feather River, and provision of a steady water supply. Construction of the Oroville Dam was completed in 1968, and the dam was opened for operations on May 4^th, 1968. The reservoir formed by the Oroville Dam is known as Lake Oroville which is the second-largest artificial lake in the state of California, having a capacity of 3.5 million acre-feet. The hydro-electric plant in Oroville Dam has a total of six turbines and has an installed capacity of 819 Megawatts and an annual generation of 1,490 GWh.

Hoover Dam

Hoover Dam is one of the largest concrete gravity-arch dams in the US found on the Colorado River, on the Nevada-Arizona border. The dam is one of the world’s largest dams and is the US’s second-tallest in the country reaching a height of 726.4 feet, only surpassed by Oroville Dam. The width at the dam’s base measures 660 feet and 45 feet at the dam’s crest. The construction of the Hoover Dam took six years between 1931 and 1936. When it was constructed, Hoover Dam was the largest construction project undertaken by the United States government at the cost of about $49 million ($700 million adjusted inflation). Construction of the Hoover Dam led to the creation of Lake Mead, a huge artificial lake which has a capacity of 28.54 acre-feet and covers an area of 247 square miles. The primary purpose of the construction of Hoover Dam was electricity generation, and the dam has an annual generation of 4.2 TWh.

Dworshak Dam

Dworshak Dam is situated in Clearwater County, Idaho and is one of the largest straight-axis concrete dams. It is the third-tallest dam and tallest of its kind in the US with a height reaching 717 feet. Construction of the Dworshak Dam began in 1966 and progressed until its completion in 1973 and cost was estimated at $327 million. While the main purpose of the construction of Dworshak Dam was electricity generation, the dam serves other purposes including flood control by containing the water levels of the Clearwater River and providing a steady supply of water through its reservoir, the Dworshak Reservoir which has a total capacity of 3.47 million acre-feet. Dworshak Dam has a maximum installed capacity of 460 MW and an annual generation of 1.693 billion kWh from its existing three turbines.

Impacts of Dam Creation

Proponents of the creation of dams state numerous benefits brought by dam creation including electricity production and provision of water. However, there is a common problem brought by dam creation which is the blocking of the natural migration routes of fish species. Remedies to alleviate the problem have been implemented including the establishment of fish hatcheries.

Tallest Dams in the United States