Department of Water Resources Home

Oroville Facilities Overview

Lake Oroville is a keystone facility of the State Water Project amd its largest reservoir with a capacity of 3.5 million acre-feet. (One acre-foot equals 325,900 gallons.)

Lake Oroville and Oroville Dam are part of a complex which includes Hyatt Powerplant, Thermalito Diversion Dam and Powerplant, the Feather River Fish Hatchery, Thermalito Power Canal, Thermalito Forebay, Thermalito Pumping- Generating Plant, Thermalito Afterbay, and the Lake Oroville Visitors Center.

The Oroville-Thermalito Complex was designed as an efficient water and power system. It stores about 3.5 million acre-feet and generates power from releases made through Hyatt Powerplant and two other Thermalito generating plants. A special fish barrier dam was built to lead salmon and steelhead, returning to spawn, into the Feather River Fish Hatchery.

Water released from Lake Oroville is used to produce electricity by Hyatt Powerplant, located in the bedrock beneath Oroville Dam. Water can either enter the Feather River or be diverted by the Thermalito Diversion Dam.

Water diverted is used to generate power by the one-unit Thermalito Diversion Dam Powerplant.

From there the water enters the Thermalito Power Canal and flows into Thermalito Forebay. At the end of the forebay, water enters the Thermalito Afterbay and is used by the Thermalito Pumping-Generating Plant to produce electricity.

The plant can also pump water back to the lake to be reused for power generation at Hyatt Powerplant.

The Feather River Fish Hatchery and the Fish Barrier Pool are located along the Feather River below the lake and the visitors center is located near Lake Oroville.

Map of Oroville-Thermalito Complex

For more information about Lake Oroville's levels, recreation and storage space:
Graph of Lake Oroville storage - DWR Division of Operations and Maintenance, includes minimum and maximum flood control space allocations.
Lake Oroville hourly report - DWR California Data Exchange Center, most recent of reservoir levels, outflow and inflow.
Reservoir levels - DWR CDEC current summary for California reservoirs and related flood-control information.