The Upper American River Project (UARP) is a

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

system operated by the

Sacramento Municipal Utility District The Sacramento Municipal Utility District (SMUD) is a community-owned electric utility serving Sacramento County and parts of Placer County. It is one of the ten largest publicly owned utilities in the United States, generating the bulk of its po ...

(SMUD) of

Sacramento ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. The system consists of 11 dams and eight powerhouses that tap the upper tributaries of the American River drainage in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

for power generation. Total installed capacity is over 687 MW, producing 1.8 billion

KWh A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bil ...

annually, enough for 20 percent of the city's electricity needs. The project mainly utilizes water from the South Fork American River and its tributaries, although some water is drawn from the

Rubicon River The Rubicon ( la, Rubico; it, Rubicone ; rgn, Rubicôn ) is a shallow river in northeastern Italy, just north of Rimini. It was known as Fiumicino until 1933, when it was identified with the ancient river Rubicon, Crossing the Rubicon, famously ...

, a tributary of the

Middle Fork American River The Middle Fork American River is one of three forks that form the American River in Northern California. It drains a large watershed in the high Sierra Nevada west of Lake Tahoe and northeast of Sacramento in Placer and El Dorado Counties, betw ...

. Project dams provide water storage of about and a total

hydraulic head Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, ...

of from the highest reservoir to the lowest powerplant outflow.

History

The UARP was authorized on August 28, 1957 by an act of the

Federal Power Commission The Federal Power Commission (FPC) was an independent commission of the United States government, originally organized on June 23, 1930, with five members nominated by the president and confirmed by the Senate. The FPC was originally created in 1 ...

. SMUD began construction in September of that year, and the first power generation from UARP came online at Jaybird Powerhouse on May 1, 1961. Most of the project facilities were completed by 1967. The Loon Lake Powerhouse was completed in 1971, and Jones Fork Powerhouse was finished in 1985. Environmental impacts include the prevention of fish passage by the project's dams, which segment parts of the upper South Fork American River, the Rubicon River and their tributaries.

Overview

Water is diverted from the Rubicon River to a storage reservoir, Loon Lake, from which it is released through the Loon Lake Powerhouse to Gerle Creek. This water is intercepted and diverted into Silver Creek, a tributary of the South Fork American River, flowing through the Robbs Peak Powerhouse into

Union Valley Reservoir Union Valley Reservoir is a reservoir in eastern El Dorado County, California, about northeast of Placerville. The lake is in Eldorado National Forest in the Sierra Nevada at an elevation of . It was formed in 1963 by the high earth and roc ...

, the project's principal reservoir. Water from Ice House Reservoir also enters Union Valley via the Jones Fork Powerhouse. From Union Valley, water flows through the Union Valley Powerhouse to Junction Reservoir, then through Jaybird Powerhouse to Camino Reservoir, both on Silver Creek. The water then enters a penstock that feeds the Camino Powerhouse above Slab Creek Reservoir on the South Fork American River. From there, water is sent through a final tunnel to White Rock Powerhouse, located on the upper end of Chili Bar Reservoir also on the South Fork.

List of facilities

† indicates a diversion dam

References

{{authority control American River (California) Hydroelectric power plants in California Sacramento Municipal Utility District Eldorado National Forest