Parker Dam is a concrete arch-gravity dam that crosses the Colorado River 155 miles (249 km) downstream of Hoover Dam. It is 320 feet (98 m) high, 235 feet (72 m) of which are below the riverbed, making it the deepest, dam in the world. The dam's primary functions are to act as a reservoir, and to generate hydroelectric power. The dam straddles the border between California and Arizona. The reservoir behind the dam is called Lake Havasu and can store 647,000 acre·ft (798,000 dam³) or over 210 billion US gallons.
The power plant has four Francis turbines with a combined capacity of 120 MW. Each turbine weighs 60,000 pounds. The head is 72 feet (22 meters). Half of the electricity the plant produces is used by the Metropolitan Water District to pump water along the Colorado River Aqueduct, and the rest is sold to utilities in California, Arizona and Nevada. The generation of power is limited by a requirement to keep the water level of Lake Havasu between 440 to 450 feet (134 to 137 meters) for recreational purposes.
Lake Havasu is the water source for the Colorado River Aqueduct. The aqueduct is operated by the Metropolitan Water District of Southern California, which supplies water to almost all cities in the greater Los Angeles and San Diego areas. The district paid for nearly the entire cost of the dam, but it is owned and operated by the U.S. Bureau of Reclamation.
Lake Havasu is also the water source for the Central Arizona Project Aqueduct (CAP). The project is designed to provide water for irrigated agricultural areas, as well as municipal water for several Arizona communities, including the metropolitan areas of Phoenix and Tucson.