Edmonston Pumping Plant

Edmonston Pumping Plant
Name	Edmonston Pumping Plant
Location	Riverside County, California, California
Coordinates	33°56′N 116°54′W
Operator	United States Bureau of Reclamation
Construction period	1963–1971
Purpose	Water supply, irrigation, municipal water transport
Capacity	2,000,000 acre-feet per year (nominal)

Edmonston Pumping Plant is a major high-lift pumping station in California that forms a critical component of the California State Water Project, the California Aqueduct, and the East Branch California Aqueduct. Located in Gene Autry, near the Santa Ana Mountains and the San Bernardino National Forest, the plant lifts water from the Colorado River Aqueduct corridor into the higher elevation reaches of the Inland Empire and Los Angeles County. It was developed by the United States Bureau of Reclamation in coordination with the California Department of Water Resources and contractors including Bechtel Corporation and Kaiser Steel as part of mid-20th century programs responding to demands from Los Angeles, San Diego, Orange County, and agricultural districts in the Central Valley.

History

The plant was conceived during planning for the California State Water Project and debates involving the Colorado River Compact, the Treaty of Guadalupe Hidalgo, and postwar expansion tied to the Bureau of Reclamation projects and the Federal Water Pollution Control Act. Groundbreaking followed high-level negotiations among the California Department of Water Resources, the United States Bureau of Reclamation, and contractors active in the 1950s and 1960s such as Bechtel Corporation and Kaiser Steel. Construction (1963–1971) occurred amid broader regional developments including the Interstate Highway System, urbanization of the Inland Empire, and agricultural shifts in the Imperial Valley. Political actors and institutions such as the California State Legislature and the United States Congress influenced funding and oversight. The plant entered operation as part of the initial system enabling water transfers to urban centers like Los Angeles and San Diego and agricultural areas served by districts including the Metropolitan Water District of Southern California.

Design and Construction

Design drew on civil and hydraulic engineering advances from projects like the Hoover Dam, the Shasta Dam, and the Grand Coulee Dam, with firms experienced in large-scale infrastructure such as Bechtel Corporation and Kaiser Steel. The site selection considered topography near the Santa Ana River drainage and the route of the California Aqueduct. Structural components reference practices codified by the American Society of Civil Engineers standards and the American Concrete Institute. Construction phases included excavation, concrete placement, turbine and pump foundation work, and installation of axial-flow pumps and electric motors supplied under contracts with major industrial firms of the era. Project management involved coordination among the United States Bureau of Reclamation, the California Department of Water Resources, regional water districts like the Metropolitan Water District of Southern California, and suppliers from the United States Department of the Interior procurement lists.

Technical Specifications

The facility comprises multiple high-head pump units arranged in a plant capable of lifting water roughly 1,926 feet (587 meters) in several stages to overcome the rise from the All-American Canal and the Chino Hills region into the San Gabriel Mountains watershed. Pumping units are powered by large synchronous motors receiving electricity from the Pacific Gas and Electric Company and regional transmission infrastructure coordinated with the California Independent System Operator. The design flow rates, unit efficiencies, and head per stage align with standards promulgated by the Hydraulics Research Station and the International Commission on Large Dams. Intake and discharge works integrate with canal linings used elsewhere in the California Aqueduct and employ surge tanks, relief valves, and control systems comparable to those at major pumping stations such as facilities on the Central Arizona Project and the All-American Canal.

Operations and Performance

Operational control is coordinated among the California Department of Water Resources, the United States Bureau of Reclamation, and regional agencies including the Metropolitan Water District of Southern California and local water agencies in Riverside County. The plant operates seasonally and in response to contractual allocations stemming from the California State Water Project and the Central Valley Project, with electricity purchases negotiated in markets overseen by the California Independent System Operator and regulated by the Federal Energy Regulatory Commission. Performance metrics include volumetric throughput tied to allocations for urban centers like Los Angeles and agricultural districts such as those in the Central Valley, operational availability comparable to other major lifts like the Palo Verde Pumping Plant, and energy intensity tracked relative to advances in pump and motor technologies developed by firms including Siemens and General Electric.

Environmental and Hydraulic Impact

Environmental assessments considered effects on habitats in the Santa Ana River corridor, downstream flows affecting riparian zones managed by agencies such as the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service, and broader impacts on the Colorado River basin allocation that involve parties to the Colorado River Compact and the Lower Colorado River Basin. Hydraulic impacts include altered flow regimes in the California Aqueduct and interactions with groundwater basins underlying regions like the Chino Basin and the Santa Ana River Groundwater Basin, with implications for recharge programs coordinated by entities such as the Orange County Water District and the Inland Empire Utilities Agency. Regulatory frameworks influencing mitigation and monitoring have included statutes and programs administered by the California Environmental Protection Agency and the United States Environmental Protection Agency, as well as litigation before courts that have addressed water rights issues involving parties like the Imperial Irrigation District.

Maintenance and Upgrades

Maintenance regimes employ scheduled overhauls of pumps, motor rewinds, and replacement of control systems using contractors experienced with heavy rotating equipment from firms such as Siemens and General Electric, and services coordinated with utilities like the Pacific Gas and Electric Company. Upgrades over time have targeted efficiency improvements, variable frequency drive retrofits informed by technology from firms like ABB and Schneider Electric, and seismic retrofits in line with standards from the United States Geological Survey and the Federal Emergency Management Agency. Asset management practices are shaped by policies from the United States Bureau of Reclamation and the California Department of Water Resources, with capital planning coordinated among water districts including the Metropolitan Water District of Southern California and state funding mechanisms administered by the California State Treasurer.

Category:California State Water Project Category:Water supply infrastructure in California