Sierra Nevada forests, Part 3C: Reservoirs of Yosemite Region

The review of the central Sierra Nevada ecoregion surrounding Yosemite National Park includes a paragraph on the other national park system unit and then continues with the reservoir systems, mostly used for hydroelectricity. The review continues next month with the national trail system and wilderness areas.

National Park System

Yosemite National Park, California, is described under World Heritage Sites. Devils Postpile National Monument, California (N37º38’ W119º5’), is known for its columnar basalt columns. It also contains 100-foot Rainbow Falls on the Middle Fork San Joaquin River. The Middle Fork San Joaquin River is eligible for the wild and scenic rivers system in the monument. Most of the monument outside of the Devils Postpile area is part of the Ansel Adams Wilderness, described separately. The Pacific Crest National Scenic Trail traverses the monument.

Reservoirs and Hydroelectric Power Projects

This section includes reservoirs federally authorized (hydroelectric projects), reservoirs located on federal lands, and reservoirs constructed by federal agencies. Because of the large number of hydroelectric developments in the Sierra Nevada, reservoirs are listed by river basin.

Kings River

Balch Afterbay, Pacific Gas & Electric, Sierra National Forest (N36º55’ W119º6’) receives water from Black Rock Reservoir (Balch Diversion Dam). Water from Balch Afterbay enters a tunnel which exits at Kings River Powerhouse on Pine Flat Lake (N36º55’ W119º10’).

Black Rock Reservoir (Balch Diversion Dam), Pacific Gas & Electric Company, California (N36º55’ W119º1’), is on the North Fork Kings River in the Sierra National Forest and receives water from the Haas Powerhouse. Water from Wishon Reservoir is diverted downstream into the Haas Tunnel, which transports water to the Haas Powerhouse above Black Rock Reservoir. Water from Black Rock Reservoir enters another tunnel which exits at the Balch Powerhouse on Balch Afterbay.

Courtright Reservoir, Pacific Gas & Electric Company, California (N37º5’ W118º59’), is on Helms Creek, a tributary of the North Fork Kings River. Campgrounds are operated by the Sierra National Forest. John Muir Wilderness borders the reservoir on the east and Dinkey Lakes Wilderness borders it on the north. Courtright is the upper storage reservoir for the Helms Pumped Storage Project.

Wishon Reservoir, Pacific Gas & Electric Company, California (N37º0’ W118º58’) is on the North Fork Kings River. Campgrounds are operated by the Sierra National Forest. John Muir Wilderness borders the reservoir on the east. At the upper end of Wishon is the Helms Powerhoure, capable of 1,212 MW of generation. The powerhouse is in a chamber 1,000 feet underground carved out of granite. Water from Wishon Reservoir is diverted to the Haas Powerhouse above Black Rock Reservoir.

Mono Basin

Rush Creek Hydroelectric Project of Southern California Edison consists of three reservoirs and a powerhouse on the June Lake Loop (State Route 168) within Inyo National Forest and Ansel Adams Wilderness. Waugh (Rush Meadows) Reservoir (N37º45’ W119º11’) and Gem Reservoir (N37º45’ W119º9’) are storage reservoirs within the wilderness, while Agnew Reservoir (N37º45’ W119º8’) feeds the penstock and powerhouse outside of the wilderness (Diamond and Hicks, 1988). Downstream of the powerhouse, Grant Lake, City of Los Angeles (N37º51’ W119º7’), diverts water to the Owens River watershed for eventual diversion to the Los Angeles Aqueduct.

Lee Vining Creek  Project of Southern California Edison consists of three reservoirs and a powerhouse along Tioga Pass Road (State Route 120) in Inyo National Forest. Saddlebag Reservoir (N37º58’ W119º17’) and Tioga Reservoir (N37º55’ W119º15’) serve as storage for Ellery (Rhinedollar) Reservoir (N37º56’ W119º14’), where water is diverted to a penstock and power is generated at Poole Powerhouse (N37º57’ W119º13’).

Lundy Reservoir, Southern California Edison (N38º2’ W119º14’) is on Mill Creek in the northern edge of Inyo National Forest. Hoover Wilderness borders the reservoir.

Owens River

The Bishop Creek Hydroelectric System of Southern California Edison is within John Muir Wilderness, Inyo National Forest, and the National System of Public Lands, as well as private and City of Los Angeles lands. It consists of reservoirs, diversion dams, and powerhouses, which have their own dams and intakes. On the South Fork Bishop Creek, South Reservoir (N37º10’ W118º34’) provides water storage. The storage is supplemented by water from Bluff Reservoir (N37º11’ W118º33’), which is on Green Creek, a tributary to South Fork Bishop Creek. Water is released from South Reservoir, passes a Weir Lake, then is diverted at the South Fork Diversion Dam (N37º14’ W118º34’) to Intake 2 Reservoir (N37º15’ W118º35’) on the Middle Fork Bishop Creek. On the Middle Fork Bishop Creek, water is also released from Sabrina Reservoir (N37º13’ W118º37’) to Intake 2 Reservoir. Intake 2 Reservoir diverts water to the Second Powerhouse (N37º16’ W118º34’).

Water is also diverted to the Second Powerhouse from storage in Longley Reservoir (N37º17’ W118º40’) on McGee Creek. Downstream from Longley Reservoir, McGee Creek Diversion Dam (N37º17’ W118º38’), Birch Creek Diversion Dam (N37º17’ W118º37’), and East Fork Birch Creek Diversion Dam (N37º16’ W118º36’) also divert water to the 2nd Powerhouse. Below the second powerhouse, another diversion dam sends water to the 3rd Powerhouse (N37º18’ W118º32’), and in turn another diversion sends water to the 4th Powerhouse (N37º19’ W118º30’), then to the 5th Powerhouse (N37º20’ W118º29’) and finally to the 6th Powerhouse (N37º21’ W118º28’) just west of the city of Bishop (Taylor, 1994).

Bluff Reservoir, Southern California Edison (N37º11’ W118º33’), is on Green Creek, a tributary to South Fork Bishop Creek, in the Inyo National Forest. Water is diverted from Green Creek to South Reservoir for hydroelectric storage as part of the Bishop Creek Hydroelectric System.

Longley Reservoir, Southern California Edison (N37º17’ W118º40’), is on McGee Creek in the John Muir Wilderness. It is a storage reservoir for the Bishop Creek Hydroelectric System.

Sabrina Reservoir, Southern California Edison (N37º13’ W118º37’), is on Middle Fork Bishop Creek in the Inyo National Forest. It borders the John Muir Wilderness.

South Reservoir (Hillside Reservoir), Southern California Edison (N37º10’ W118º34’), is on South Fork Bishop Creek in the Inyo National Forest and is used as a storage reservoir for the Bishop Creek Hydroelectric System.

 

 San Joaquin River

The Big Creek Hydroelectric Development of Southern California Edison is accessed from State Route 168 and consists of multiple reservoirs and tunnels in the Sierra National Forest. The complex system is on the South Fork San Joaquin River, San Joaquin River, and Big Creek, all of which are near SR 168. The uppermost reservoirs are on the South Fork San Joaquin River and tributaries. Florence Lake (N37º16’ W118º58’) is on the South Fork San Joaquin River. Its water is supplemented by a diversion dam on Hooper Creek (N37º18’ W118º57’). Water from Florence Lake is diverted into the Ward Tunnel. Water from Chinquapin (N37º18’ W119º1’), Camp 62 (N37º18’ W119º2’), and Bolsillo (N37º19’ W119º2’) Creeks is also diverted to the Ward Tunnel. Lake Thomas A. Edison (N37º23’ W118º59’)) receives water from Mono Creek and Warm Creek. The Mono Creek Diversion Dam (N37º21’ W119º0’) below Lake Thomas A. Edison and the Bear Creek Diversion Dam (N37º20’ W118º59’) divert water to the Mono-Bear Siphon, which also feeds the Ward Tunnel. Ward Tunnel passes the Portal Forebay (N37º19’ W119º4’), where it captures water from Camp 61 Creek, then exits the tunnel through Portal powerhouse at Huntington Lake (N37º14’ W119º12’).

Water from Huntington Lake (Big Creek Dam 3 Reservoir) may be diverted through three pathways. Tunnel 1 leads to a powerhouse above Big Creek Dam 4 Reservoir (N37º12’ W119º14’). Tunnel 7 delivers water to North Fork Stevenson Creek, a tributary of Shaver Lake, or as is usually the case, Tunnel 7 delivers water to Balsam Meadows Forebay (N37º10’ W119º15’). Tunnel 7 also receives diverted water from Pittman Creek (N37º12’ W119º13’). If sent to Balsam Meadows Forebay, the water passes through the Eastwood Powerhouse on Shaver Lake (N37º8’ W119º7’). Shaver Lake is operated as a pumped storage facility with Balsam Meadows Forebay, which is not on national forest lands.

Water from Shaver Lake is diverted through Tunnel 5 to a powerhouse on Big Creek Dam 5 reservoir (N37º12’ W119º18’). Big Creek Dam 5 reservoir also receives water via Tunnel 2 from Big Creek Dam 4 Reservoir. Water in Tunnel 2 is supplemented by water from Balsam Creek (N37º11’ W119º16’) and Ely Creek (N37º11’ W119º17’).

On the San Joaquin River is Mammoth Pool Reservoir (N37º20’ W119º19’). Water from Mammoth Pool is diverted to a powerhouse on Big Creek Dam 6 (N37º12’ W119º20’), which is on the San Joaquin River. Dam 6 also receives water from Big Creek Dam 5 reservoir. The powerhouse on Dam 6 also receives water diverted from Rock Creek (N37º16’ W119º20’) and Ross Creek (N37º14’ W119º21’).

Below Big Creek Dam 6, water is diverted through Tunnel 3 to Redinger Lake (N37º9’ W119º27’). Water from Redinger Reservoir is diverted to a powerhouse on the upper end of Kerckhoff Reservoir (N37º8’ W119º31’), which is operated by Pacific Gas & Electric. Kerckoff Powerhouse (N37º6’ W119º33’) is just above Millerton Lake in the California interior chaparral and woodlands ecoregion. The major dams of the Big Creek hydroelectric project are listed below.

Balsam Meadow Forebay, Southern California Edison (N37º10’ W119º15’) is on West Fork Balsam Creek, a tributary of the San Joaquin River. It is a pumped storage reservoir operated in conjunction with Shaver Lake. It receives water from Huntington Lake.

Bear Creek Diversion Dam, Southern California Edison (N37º20’ W118º58’), is on Bear Creek in the Sierra National Forest, a tributary of the South Fork San Joaquin River. Water is diverted via tunnel to Huntington Lake, where power is generated.

Big Creek Dam 4, Southern California Edison (N37º12’ W119º14’), has a powerhouse that receives water from Huntington Lake for power generation. It is on Sierra National Forest land.

Big Creek Dam 5, Southern California Edison (N37º12’ W119º18’) receives water via tunnels from Big Creek Dam 4 and from Shaver Lake. It is on Sierra National Forest land.

Big Creek Dam 6, Southern California Edison (N37º12’ W119º20’), is on the San Joaquin River and receives water via tunnels from Big Creek Dam 5 and from Mammoth Pool Reservoir. It is on Sierra National Forest land.

Lake Thomas A. Edison (Vermillion Valley Dam), Southern California Edison (N37º23’ W118º59’), is on Mono Creek, a tributary to the South Fork San Joaquin River. It contains private resorts and campgrounds operated by Sierra National Forest. John Muir Wilderness borders the reservoir on the east and Ansel Adams Wilderness borders it on the west. Below Vermillion Valley Dam is Mono Creek Diversion Dam (N37º21’ W119º0’). Here, water from Lake Thomas A. Edison is diverted to Portal Powerhouse at the upper end of Huntington Lake. It is accessed from Forest Highway 80 (Kaiser Pass Road) from Huntington Lake.

Florence Lake, Southern California Edison (N37º16’ W118º58’), is on the South Fork San Joaquin River and contains private resorts and campgrounds operated by Sierra National Forest. It is accessed via Forest Highway 80 and Forest Road 7S01 from Huntington Lake. John Muir Wilderness surrounds the reservoir. Water from Florence Lake is diverted to the Portal Powerhouse at the upper end of Huntington Lake.

Huntington Lake (Big Creek Dam 3), Southern California Edison, California (N37º14’ W119º12’), is on Sheep Thief Creek, a tributary to the San Joaquin River, and contains private resorts and winter sports areas with campgrounds operated by Sierra National Forest. It is accessed by State Route 168.

Mammoth Pool Reservoir, Southern California Edison (N37º20’ W119º19’) is on the San Joaquin River in the Sierra National Forest. Ansel Adams Wilderness borders the reservoir on its north end. Water is diverted via tunnels to a powerhouse on Big Creek Dam 6.

Portal Forebay, Southern California Edison (N37º19’ W119º4’), is on Camp 61 Creek, a tributary to the San Joaquin River, and is part of the Big Creek Hydroelectric Development in Sierra National Forest. It is located along Kaiser Pass Road and contributes water to the hydroelectric tunnels leading to Huntington Lake.

Redinger Reservoir, Southern California Edison (N37º9’ W119º27’) is on the San Joaquin River in the Sierra National Forest and receives water from Big Creek Dam No. 6.

Shaver Lake, Southern California Edison, California (N37º8’ W119º17’) is on Stevenson Creek, a tributary of the San Joaquin River. Some Sierra National Forest land borders the reservoir. Access is provided by State Route 168. It receives water from Huntington Lake and pumped storage projects. Water from Shaver Lake is diverted to the Big Creek Hydroelectric facilities. The Museum of the Central Sierra is on reservoir lands donated by Southern California Edison.

Other dams on the San Joaquin River and tributaries include two hydroelectric projects operated by Pacific Gas & Electric, Crane Valley and Kerckhoff. The Crane Valley Hydroelectric Project consists of Chilkoot Lake, Browns Creek Diversion Dam, Bass Lake, San Joaquin Powerhouse No. 3 Forebay, Manzanita Lake, South Fork Willow Creek Diversion Dam, North Fork Willow Creek Diversion Dam, and Corrine Lake. On the North Fork Willow Creek in the Sierra National Forest is the Crane Valley Hydroelectric Development of Pacific Gas and Electric Company. The uppermost reservoir of this development is Chilkoot Lake (N37º25’ W119º29’), which is a storage reservoir. Downstream is the largest of the development, Bass Lake (N37º18’ W119º32’), formed by Crane Valley Dam. Supplemental water is diverted to Bass Lake from the Browns Creek Diversion Dam (N37º18’ W119º30’). From the powerhouse at Bass Lake, the water is diverted through tunnels to a forebay at San Joaquin No. 3 Powerhouse (N37º15’ W119º32’). The outflow from the powerhouse goes into Manzanita Lake (N37º15’ W119º31’). From Manzanita Lake water is diverted to the San Joaquin No. 2 Forebay (N37º12’ W119º30’), where additional power is generated. Water from San Joaquin No. 2 forebay is supplemented through diversion dams on the South Fork Willow Creek and North Fork Willow Creek (both N37º13’ W119º30’). From San Joaquin No. 2, water is sent to the San Joaquin No. 1A Powerhouse, which discharges into Corrine Lake (N37º10’ W119º30’). Water from Corrine Lake is sent through the A.G. Wishon powerhouse to the San Joaquin River (PGE 2006).

Bass Lake, Pacific Gas & Electric, California (N37º18’ W119º32’) is on the North Fork Willow Creek in the Sierra National Forest. N. Fork Willow is a San Joaquin River tributary. Recreation areas are operated by private marinas and the Sierra National Forest.

Kerckhoff Diversion Dam, Pacific Gas & Electric (N37º8’ W119º31’) is on the San Joaquin River in the Sierra National Forest and National System of Public Lands. Kerckoff Powerhouse (N37º6’ W119º33’) is just above Millerton Lake on the National System of Public Lands.

Manzanita Lake, Pacific Gas & Electric (N37º15’ W119º31’) is on the North Fork Willow Creek. Some Sierra National Forest land adjoins the reservoir.

Stanislaus River, Middle and South Forks

Beardsley Reservoir (N38º13’ W120º4’) and Beardsley Afterbay (N38º12’ W120º5’) are on the Middle Fork Stanislaus River in the Stanislaus National Forest and are operated by the Tri-Dam Project, a partnership of the South San Joaquin and Oakdale Irrigation Districts. It is reached from State Route 108 at Strawberry via Forest Highway 52.

Donnell Reservoir (N38º20’ W119º57’) is on the Middle Fork Stanislaus River in the Stanislaus National Forest and is operated by the Tri-Dam Project. It is visible from State Route 108. The reservoir adjoins the Carson-Iceberg Wilderness.

Herring Creek Reservoir (N38º15’ W119º56’) is operated by the Stanislaus National Forest for recreation.

Lyons Reservoir, Pacific Gas & Electric Company (N38º6’ W120º10’), is on the South Fork Stanislaus River in the Stanislaus National Forest off State Route 108. Water is diverted via the Tuolumne Ditch to Sullivan Creek, and power is generated at the Phoenix Reservoir Powerhouse (N38º0’ W120º19’) on Sullivan Creek near Sonora.

Pinecrest (Strawberry) Reservoir, Pacific Gas & Electric Company (N38º12’ W119º59’) is on the South Fork Stanislaus River and accessed from State Route 108 in the Stanislaus National Forest. Water is diverted to the Spring Gap Powerhouse on the Middle Fork Stanislaus River for power generation. This reservoir is part of the Spring Gap-Stanislaus Hydroelectric Project.

Relief Reservoir, Pacific Gas & Electric Company (N38º16’ W119º44’) is on Summit Creek in the Stanislaus National Forest headwaters of the Middle Fork Stanislaus River. It adjoins Emigrant Wilderness and provides supplemental water to downstream reservoirs. Power is generated at the Spring Gap Powerhouse and Stanislaus Powerhouse downstream from Beardsley Lake Afterbay. Relief Reservoir is part of the Spring Gap-Stanislaus Hydroelectric Project.

Sand Bar Dam, Pacific Gas & Electric Company (N38º11’ W120º9’) diverts water from the Middle Fork Stanislaus into a tunnel, which provides water to the Stanislaus Powerhouse (N38º8’ W120º22’) on New Melones Reservoir. Sand Bar Dam is part of the Spring Gap-Stanislaus Hydroelectric Project.

Spring Gap Dam and Powerhouse, Pacific Gas & Electric Company (N38º11’ W120º7’), on the Middle Fork Stanislaus River, receives water from the Pinecrest Lake Diversion on the South Fork Stanislaus River. Spring Gap Dam is part of the Spring Gap-Stanislaus Hydroelectric Project.

Stanislaus River, North Fork

Lake Alpine (N38º29’ W120º0’), Northern California Power Agency, is on Silver Creek adjacent to State Route 4 as well as the Carson-Iceberg Wilderness.

Beaver Creek Diversion Dam, Calaveras County Water District (N38º14’ W120º7’), diverts water to McKays Point Reservoir for power generation.

Hunter’s Reservoir (N38º12’ W122º22’) is operated by the Utica Water and Power Authority. The dam stores water and diverts it into the Utica Canal, which crosses Stanislaus National Forest land on the way to Murphy’s Powerhouse along State Route 4 (N38º9’ W120º26’).

McKay’s Point Diversion Dam, Calaveras County Water District (N38º14’ W120º17’) is the entry point for an 8.5-mile tunnel to Collierville Powerhouse (N38º9’ W120º23’), where power is generated.

New Spicer Meadows Reservoir, Calaveras County Water District (N38º24’ W120º0’) is on Highland Creek and is used for storage. It is adjacent to Carson-Iceberg Wilderness.

North Fork Diversion Dam, Calaveras County Water District (N38º26’ W120º1’) sends water from the North Fork Stanislaus River to New Spicer Meadow Reservoir for storage.

Union Reservoir and Utica Reservoir, Northern California Power Agency (N38º26’ W120º0’) are the uppermost reservoirs on the North Fork Stanislaus River. Both release water to the North Fork Diversion Dam (N38º26’ W120º1’) of Calaveras County Water District.

Tuolumne River

Cherry Lake, City of San Francisco (N38º0’ W119º54’) is in the Stanislaus National Forest to the west of Yosemite National Park. Its water is supplemented with a tunnel from Lake Eleanor to the east. Hydroelectric power from Lake Eleanor and Cherry Lake water is generated at the 169-MW Holm Powerhouse (N37º54’ W119º58’) on Cherry Creek in the Stanislaus National Forest.

Lake Eleanor, City of San Francisco, California (N37º59’ W119º52’) is part of the Hetch Hetchy hydroelectric development completed in 1918 by the City in the northwestern edge of Yosemite National Park. A tunnel to the west transfers some Lake Eleanor water to Cherry Lake for storage. Eleanor Creek is a tributary to Cherry Creek, which in turn is a tributary to the Tuolumne River. Hydroelectric power from Lake Eleanor and Cherry Lake water is generated at the 169-MW Holm Powerhouse (N37º54’ W119º58’) on Cherry Creek in the Stanislaus National Forest.

Hetch Hetchy Reservoir, City of San Francisco (N37º57’ W119º47’) is surrounded by Yosemite National Park and was the subject of one of the epic battles in environmental history. The Sierra Club fought to prevent the dam in the Tuolumne River canyon, but the dam and hydroelectric development by the City of San Francisco was authorized by Congress in 1913. The reservoir was completed in 1923. Hydroelectric power from the reservoir is generated at Kirkwood Powerhouse (N37º53’ W119º57’) on the Tuolumne River in the Stanislaus National Forest and at Moccasin Powerhouse (N37º49’ W120º18’) on the Hetch Hetchy Aqueduct at the junction of State Routes 49 and 120 above Don Pedro Reservoir. The Hetch Hetchy Aqueduct continues to the San Francisco Bay area (Crystal Springs Reservoir) and provides drinking water to the metropolitan area.