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O`Neill Powerplant *

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Related Projects & Facilities
O`Neill Dam
San Luis Unit Project
Related Documents
O`Neill Pump-Generating Plant Performance (pdf)

* Plant owned by Reclamation but operated by a separate entity. Generation is marketed by the Western Area Power Administration, a Federal Power Marketing Administration.


RegionFacilities in Mid-Pacific | Mid-Pacific Home Page
RiverSan Luis Creek
PurposeThe O`Neill Pump-Generating Plant pumps Central Valley Project water for offstream storage.
FactsThe O`Neill Pump-Generating Plant consists of an intake channel leading off the Delta-Mendota Canal and six pump-generating units. Normally these units operate as pumps to lift water from 45 to 53 feet into the O`Neill Forebay. Water is occasionally released from the forebay to the Delta-Mendota Canal, and these units then operate as generators. When operating as pumps and motors, each unit can discharge 700 cubic feet per second and has a rating of 6,000 horse-power. When operating as turbines and generators, each unit has a generating capacity of about 4,200 kilowatts.
HistoryThe pump-generating plant was turned over to Delta-Mendota Canal Authority for maintenance in 1994.
Present ActivitiesNormal operations. The plant pumps water from Delta-Mendota Canal to O`Neill Forebay. It offsets Central Valley Project pumping loads with generating during releases to Delta-Mendota Canal.
Special IssuesO`Neill, which operates primarily as a pumping plant only generates part of the year. The authorizing legislation for O`Neill states that power generated at the facility cannot be used for commercial purposes. Therefore, the generation produced at O`Neill is allocated as project-use power for the Central Valley Project and the cost associated with generation is allocated to the irrigation component of Central Valley Project.
NERC RegionWestern Electricity Coordinating Council, California-Southern Nevada Power Area
PMA Service AreaWestern Area Power Administration, Sierra Nevada Region
Plant TypeConventional
Powerhouse TypeAbove Ground
Turbine TypeVIP Pitch
Original Nameplate Capacity25,200 kW
Installed Capacity25,200 kW
Year of Initial Operation1967
Age40 years
Net Generation5,404,000 kWh
(Fiscal Year)2007
Rated Head50 ft
Plant Factor2.7 percent
(Fiscal Year)2007
Production ModePeaking
Remotely OperatedYes
Project AuthorizationFunds for construction of the initial features of the Central Valley Project were provided by the Emergency Relief Appropriation Act of 1935 (49 Stat. 115). The Secretary of the Interior authorized the project and the President approved it on December 2, 1935.
Project AuthorizationThe San Luis Unit, West San Joaquin Division, was authorized as a part of the Central Valley Project on June 3, 1960, Public Law 86-488.
Project PurposeThe Central Valley Project, one of the Nation`s major water conservation developments, extends from the Cascade Range on the north to the semiarid but fertile plains along the Kern River on the south. Initial features of the project were built primarily to protect the Central Valley from crippling water shortages and menacing floods. New project units were built to provide water and power to match the continued growth of the State.
Project PurposeAlthough developed primarily for irrigation, this multiple-purpose project also provides flood control, improves Sacramento River navigation, supplies domestic and industrial water, generates electric power, conserves fish and wildlife, creates opportunities for recreation, and enhances water quality.
OrganizationSan Luis-Delta Mendota Water Authority
Phone (Office)209 832-6245

Last updated: Dec 16, 2013