Parker Dam

Parker Dam
Name	Parker Dam
Location	Colorado River, border of California and Arizona
Coordinates	34°8′45″N 114°21′30″W
Operator	Bureau of Reclamation
Dam type	Concrete arch-gravity
Length	1,320 ft (402 m)
Height	320 ft (98 m)
Construction began	1934
Opening	1938
Reservoir	Lake Havasu
Reservoir capacity	646,000 acre-feet
Plant capacity	120 MW

Parker Dam Parker Dam is a concrete arch-gravity dam on the Colorado River at the California–Arizona border, forming Lake Havasu and serving as a key component of water distribution infrastructure in the Southwestern United States. Built in the 1930s by the United States Bureau of Reclamation with labor from the Metropolitan Water District of Southern California and other contractors, the facility supports water diversion for the Central Arizona Project and the Colorado River aqueduct, while hosting a hydroelectric plant operated by the Western Area Power Administration. Parker Dam occupies a strategic location between Davis Dam downstream and Hoover Dam upstream, linking regional water delivery and power networks.

History

The site of Parker Dam gained attention during early 20th-century debates about water allocation in the Colorado River Compact era and following reclamation projects like Hoover Dam and Grand Coulee Dam. Proposals to exploit the low-gradient reach near Parker, Arizona and Earp, California date to planning by the Bureau of Reclamation and state water agencies. Groundbreaking occurred in 1934 amid the socioeconomic context of the Great Depression, when federal public works programs and regional utilities sought to create employment and secure water supplies for urbanizing regions such as Los Angeles, San Diego, and Phoenix. Construction involved relocation of workers, negotiation with Salt River Project stakeholders, and legal coordination under interstate compacts and federal statutes, including provisions arising from the Boulder Canyon Project framework.

The dam was completed in 1938, timed with expansion of the Colorado River aqueduct and preliminary planning for the Central Arizona Project. Its completion affected preceding riparian land uses of Chemehuevi Indian Reservation and tribal claims by the Colorado River Indian Tribes, prompting legal and administrative arrangements. Throughout the mid-20th century, Parker Dam featured in litigation and interstate cooperation concerning apportionment from the Colorado River Basin, and later in environmental discourse linked to the Endangered Species Act and water quality regulations administered by agencies such as the United States Environmental Protection Agency.

Design and Construction

Parker Dam's design as a concrete arch-gravity structure reflects engineering practices developed by firms and engineers engaged with major western projects like Hoover Dam and Glen Canyon Dam. The dam was engineered to resist hydraulic thrust via a curved axis transmitting loads into canyon abutments composed of Precambrian and Mesozoic formations studied by geologists associated with institutions including the United States Geological Survey and state geological surveys. Design parameters incorporated lessons from early 20th-century projects undertaken by the Bureau of Reclamation and consulting engineers who previously worked on flood-control and diversion facilities.

Construction required cofferdams, diversion tunnels, and extensive concrete placement techniques influenced by contractors experienced in large-scale dams. Workforce housing, supply chains, and transport logistics were coordinated with regional railroads and municipal utilities in Arizona and California. Materials testing, concrete mix design, and quality control were overseen by engineers trained at institutions such as Massachusetts Institute of Technology and Stanford University who were active in western dam construction. The powerplant and intake works were integrated into the structure to support hydroelectric generation and pumping plants associated with the Colorado River Aqueduct operations managed by the Metropolitan Water District of Southern California.

Specifications and Operations

Parker Dam is 320 feet high and approximately 1,320 feet long, impounding Lake Havasu with a capacity around 646,000 acre-feet. The facility includes a hydroelectric plant with a capacity in the low hundreds of megawatts; generation and transmission are coordinated with the Western Area Power Administration and regional utilities including the Metropolitan Water District of Southern California and the Salt River Project. Water diverted at Parker Dam feeds the Colorado River Aqueduct toward southern California and interfaces with diversion works for the Central Arizona Project which supplies Phoenix and Tucson.

Operations are governed by interstate compacts, notably the Colorado River Compact and agreements stemming from the Boulder Canyon Project Act, as well as federal oversight by the Department of the Interior. Release schedules, seasonal storage, and power dispatch are coordinated with downstream facilities such as Davis Dam and upstream reservoirs like Lake Mead behind Hoover Dam. Monitoring and maintenance programs involve structural inspections, seismic assessments following criteria from agencies like the Federal Energy Regulatory Commission, and water-quality monitoring in cooperation with state water boards.

Environmental and Hydrological Impact

Parker Dam altered preexisting fluvial and riparian ecosystems by converting a stretch of the Colorado River into Lake Havasu, affecting habitats for species regulated under the Endangered Species Act and prompting studies by the United States Fish and Wildlife Service. The impoundment changed sediment transport, river temperature regimes, and floodplain connectivity, with implications for native fishes such as the humpback chub and riparian vegetation communities historically used by the Chemehuevi and Mojave peoples. Coordination with environmental programs, reservoir management strategies, and mitigation efforts have involved federal and state agencies including the Bureau of Land Management and the California Department of Fish and Wildlife.

Hydrologically, Parker Dam functions in the broader Colorado River Basin water storage and allocation network that has experienced multi-decadal drought, extended low reservoir elevations, and legal negotiation under the Law of the River. Climate variability and upstream diversions by projects like the Glen Canyon Dam and Palo Verde Irrigation District influence inflows to Lake Havasu, prompting adaptive management discussions among stakeholders such as the Seven Basin States and federal authorities.

Recreation and Access

Lake Havasu created by the dam is a regional recreation destination attracting boating, angling, and shoreline activities managed by entities including the Arizona Game and Fish Department and local tourism bureaus of Mohave County, Arizona and San Bernardino County, California. Access points, marinas, and parklands near cities such as Lake Havasu City and Parker, Arizona support recreational economies tied to water levels and permitting administered by the Bureau of Reclamation. The site is also a point of interest for visitors to nearby engineered landmarks and infrastructures like the relocated London Bridge (Lake Havasu City), and is integrated into interpretive programs addressing western water history.

Category:Dams on the Colorado River Category:Dams in Arizona Category:Dams in California