California Aqueduct

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California Aqueduct
Kluft-Photo-Aerial-I205-California-Aqueduct-Img 0038.jpg
The Delta–Mendota Canal (left) and the California Aqueduct (right) near Tracy, California
Coordinates 37°49′47″N121°33′25″W / 37.8297°N 121.557°W / 37.8297; -121.557
Begins Clifton Court Forebay, Contra Costa County
37°49′47″N121°33′25″W / 37.82972°N 121.55694°W / 37.82972; -121.55694
EndsWest Branch
Castaic Lake, Los Angeles County
34°35′15″N118°39′25″W / 34.587379°N 118.656893°W / 34.587379; -118.656893
East Branch
Silverwood Lake, San Bernardino County
34°18′12″N117°19′12″W / 34.303457°N 117.319908°W / 34.303457; -117.319908
Coastal Branch
Lake Cachuma, Santa Barbara County
34°35′12″N119°58′52″W / 34.586656°N 119.980975°W / 34.586656; -119.980975
Official nameGovernor Edmund G. Brown California Aqueduct
Maintained by California Department of Water Resources
Characteristics
Total lengthTotal: 444 mi (715 km)
Main: 304 mi (489 km)
East Branch: 140 mi (230 km)
Width110 ft (34 m) max.
Height40 ft (12 m) max.
Capacity13,100 cu ft/s (370 m3/s) max
History
Construction start1963
Opened
  • Coastal Branch Phase 1 - 1968
  • Coastal Branch Phase 2 - 1997
  • East Branch - ?
  • East Branch San Gorgonio Pass extension - 2002 [1]
  • West Branch - ?
  • Delta–Mendota Canal Intertie - 2012 [2]
Location
California Aqueduct
References
[3]

The Governor Edmund G. Brown California Aqueduct is a system of canals, tunnels, and pipelines that conveys water collected from the Sierra Nevada Mountains and valleys of Northern and Central California to Southern California. [4] Named after California Governor Edmund Gerald "Pat" Brown Sr., the over 400-mile (640 km) aqueduct is the principal feature of the California State Water Project.

Contents

The aqueduct begins at the Clifton Court Forebay at the southwestern corner of the Sacramento–San Joaquin River Delta. The aqueduct then heads south, eventually splitting into three branches: the Coastal Branch, ending at Lake Cachuma in Santa Barbara County; the West Branch, conveying water to Castaic Lake in Los Angeles County; and the East Branch, connecting Silverwood Lake in San Bernardino County.

The Department of Water Resources (DWR) operates and maintains the California Aqueduct, including one pumped-storage hydroelectric plant, Gianelli Power Plant. Gianelli is located at the base of San Luis Dam, which forms San Luis Reservoir, the largest offstream reservoir in the United States. [5]

The Castaic Power Plant, while similar and which is owned and operated by the Los Angeles Department of Water and Power, is located on the northern end of Castaic Lake, while Castaic Dam is located at the southern end.

Land subsidence has occurred along the aqueduct and has had a steady increase since its relatively stable state post construction of the aqueduct.

The aqueduct system

San Luis Reservoir in July 2021 Banks of San Luis Reservoir in July 2021 redux.JPG
San Luis Reservoir in July 2021

The aqueduct serves 35 million people and 5.7 million acres of farmland, [6] and begins at the San Joaquin-Sacramento River Delta at the Banks Pumping Plant, which pumps from the Clifton Court Forebay. Water is pumped by the Banks Pumping Plant to the Bethany Reservoir. The reservoir serves as a forebay for the South Bay Aqueduct via the South Bay Pumping Plant. From the Bethany Reservoir, the aqueduct flows by gravity approximately 60 mi (97 km) to the O'Neill Forebay at the San Luis Reservoir. From the O'Neill Forebay, it flows approximately 16 mi (26 km) to the Dos Amigos Pumping Plant. After Dos Amigos, the aqueduct flows about 95 mi (153 km) to where the Coastal Branch splits from the "main line". The split is approximately 16 mi (26 km) south-southeast of Kettleman City. After the coastal branch, the line continues by gravity another 66 mi (106 km) to the Buena Vista Pumping Plant. From the Buena Vista, it flows approximately 27 mi (43 km) to the Teerink Pumping Plant. After Teerink it flows about 2.5 mi (4.0 km) to the Chrisman Pumping Plant. Chrisman is the last pumping plant before Edmonston Pumping Plant, which is 13 mi (21 km) from Chrisman. South of the plant the west branch splits off in a southwesterly direction to serve the Los Angeles Basin. At Edmonston Pumping Plant it is pumped 1,926 ft (587 m) over the Tehachapi Mountains. [7]

Water flows through the aqueduct in a series of abrupt rises and gradual falls. The water flows down a long segment, built at a slight grade, and arrives at a pumping station powered by Path 66 or Path 15. The pumping station raises the water, where it again gradually flows downhill to the next station. However, where there are substantial drops, the water's potential energy is recaptured by hydroelectric plants. The initial pumping station fed by the Sacramento River Delta raises the water 240 ft (73 m), while a series of pumps culminating at the Edmonston Pumping Plant raises the water 1,926 ft (587 m) over the Tehachapi Mountains.

A typical section has a concrete-lined channel 40 feet (12 m) at the base and an average water depth of about 30 ft (9.1 m). The widest section of the aqueduct is 110 feet (34 m) and the deepest is 32 feet (9.8 m). Channel capacity is 13,100 cubic feet per second (370 m3/s) and the largest pumping plant capacity at Dos Amigos is 15,450 cubic feet per second (437 m3/s).

A 2021 study published in Nature Sustainability estimated that the installation of solar panels over the canal could potentially reduce annual water evaporation by 11–22 million US gallons per mile (27,000,000–51,000,000 L/km) of canal. While electricity generated by the solar panels could be used by the aqueduct's pumping systems, the study also considered the possibility of supplying power to irrigation systems in the Central Valley to reduce reliance on diesel-powered irrigation pumps. Similar canal-spanning solar installations have been demonstrated in India, including a steel truss design in Gujarat and a suspension cable design in Punjab. [8]

Branches

From its beginning until its first branch, the aqueduct passes through parts of Contra Costa, Alameda, San Joaquin, Stanislaus, Merced, Fresno, and Kings counties. The aqueduct then divides into three branches: the Coastal Branch in the Central Valley, and the East and West Branches after passing over the Tehachapi Mountains.

Aqueduct and surrounding farms in Kern County Kern-County-farms-and-california-aqueduct-Aerial-from-west-August-2014.jpg
Aqueduct and surrounding farms in Kern County

Coastal Branch

The Coastal Branch splits from the main line 11.3 mi (18.2 km) south-southeast of Kettleman City transiting Kings County, Kern County, San Luis Obispo County, and Santa Barbara County to deliver water to the coastal cities of San Luis Obispo, Santa Maria, and Santa Barbara. [9] The Coastal Branch is 116 mi (187 km) and has five pump stations. Phase I, an above-ground aqueduct totaling 15 mi (24 km) from where it branches from the California Aqueduct, was completed in 1968. With construction beginning in 1994, Phase II consists of 101 mi (163 km) of a 42–57-inch (1.07–1.45 m) diameter buried pipeline extending from the Devils Den Pump Plant, and terminates at Tank 5 on Vandenberg Space Force Base in Santa Barbara County. The Central Coast Water Authority (CCWA) extension, completed in 1997, is a (30–39 in) (76–99 cm) diameter pipeline that travels 42 mi (68 km) from Vandenberg through Vandenberg Village, Lompoc, Buellton, and Solvang where it terminates at Lake Cachuma in Los Padres National Forest. [10]

Coastal Branch facilities include: [11]

East Branch

The California Aqueduct East Branch, flowing east after crossing under state route 138 California Aqueduct east of route 138.jpg
The California Aqueduct East Branch, flowing east after crossing under state route 138

The aqueduct splits off into the East Branch and West Branch in extreme southern Kern County, north of the Los Angeles County line. The East Branch supplies Lake Palmdale and terminates at Lake Perris, in the area of the San Gorgonio Pass. It passes through parts of Kern, Los Angeles, San Bernardino, and Riverside counties.

East Branch facilities include: [11]

West Branch

The West Branch continues to head towards its terminus at Pyramid Lake and Castaic Lake in the Angeles National Forest to supply the western Los Angeles basin. It passes through parts of Kern and Los Angeles counties.

West Branch facilities include [11]

Bikeway

When it was open, the California Aqueduct Bikeway was the longest of the paved paths in the Los Angeles area, at 107 miles (172 km) long from Quail Lake near Gorman in the Sierra Pelona Mountains through the desert to Silverwood Lake in the San Bernardino Mountains. This path was closed in 1988 due to bicyclist safety and liability issues. It is expected to remain closed indefinitely due to the continued liability issues and an increased focus on security, especially after the September 11, 2001 attacks.

California Aqueduct fishing spot near Pearblossom.jpg
Fishing spot and closed bikeway near Pearblossom, panoramic view

Pumping stations

Phase I, canal
Phase II, pipeline and tunnel

Hydrography

Sacramento River basin map.png
Sacramento River watershed
San Joaquin River watershed.png
San Joaquin River watershed and Tulare Basin

Two major river systems drain and define the two parts of the Central Valley. Their impact on the California Aqueduct is both direct and indirect. The Sacramento River, along with its tributaries the Feather River and American River, flows southwards through the Sacramento Valley for about 447 miles (719 km). [13] In the San Joaquin Valley, the San Joaquin River flows roughly northwest for 365 miles (587 km), picking up tributaries such as the Merced River, Tuolumne River, Stanislaus River and Mokelumne River. [14]

In the south part of the San Joaquin Valley, the alluvial fan of the Kings River and another one from Coast Ranges streams have created a divide and resultantly the currently dry Tulare basin of the Central Valley, into which flow four major Sierra Nevada rivers, the Kings, Kaweah, Tule and Kern. This basin, usually endorheic, formerly filled during heavy snowmelt and spilled out into the San Joaquin River. Called Tulare Lake, it is usually dry nowadays because the rivers feeding it have been diverted for agricultural purposes. [15]

The rivers of the Central Valley converge in the Sacramento-San Joaquin Delta, a complex network of marshy channels, distributaries and sloughs that wind around islands mainly used for agriculture. Here the freshwater of the rivers merges with tidewater, and eventually reach the Pacific Ocean after passing through Suisun Bay, San Pablo Bay, upper San Francisco Bay and finally the Golden Gate. Many of the islands now lie below sea level because of intensive agriculture, and have a high risk of flooding, which would cause salt water to rush back into the delta, especially when there is too little fresh water flowing in from the Valley. [16]

The Sacramento River carries far more water than the San Joaquin, with an estimated 22 million acre-feet (27 km3) of virgin annual runoff, as compared to the San Joaquin's approximately 6 million acre-feet (7.4 km3). Intensive agricultural and municipal water consumption has reduced the present rate of outflow to about 17 million acre-feet (21 km3) for the Sacramento and 3 million acre-feet (3.7 km3) for the San Joaquin; however, these figures still vary widely from year to year. Over 25 million people, living both in the valley and in other regions of the state, rely on the water carried by these rivers. [17]

Land subsidence

Background

Land subsidence is when the land gradually or suddenly sinks or settles due to movement or removal of natural materials such as water, minerals, oil and natural gases. [18] More often than not, subsidence occurs when large quantities of groundwater are removed from sediment or rocks. [19] As groundwater is drawn from deep underground layers of clay, the clay compresses, causing subsidence. [20] In cases of groundwater removal, disruption to land on the surface and underground water storage can either be elastic, meaning recoverable, or inelastic, meaning permanent. [21] Coarse-grained sediment which holds groundwater can be drained and recharged with minimal underground and surface level damage and the change that does occur is considered seasonal subsidence. [21] However, fine-grained sediment takes longer to draw water out of and recharge and if groundwater levels are left low for too long, the compaction of the sediment is permanent and causes irreversible land subsidence. [21] This often occurs due to human interference, but can also happen from natural phenomena. Subsidence can happen over very large areas or small little sections of land. [18] This has occurred along the California Aqueduct of the State Water Project since construction.

Human causes include; pumping, mining and fracking. [18]

Natural causes include; earthquakes, erosion, glacial movement, soil compaction and the formation of sinkholes. [18]

Groundwater use and pumping in the area was the major water use for farmers and agriculture in the 1920s, and over time, this over-pumping resulted in land subsidence and a decline in groundwater-level resources. In time, this resulted in major land subsidence by the 1970s with local areas having 1 to 28 feet of subsidence. With the creation and use of the California Aqueduct along these regions, surface water being transported put a halt on significant compaction and a recovery in ground water levels now with less ground water pumping. [22] The aqueduct has been increasing in subsidence rates rapidly, even though it was relatively stable for many years after being constructed. [23] The Tulare Basin is subsiding at a rate of about one foot per year, as measured by NASA's GRACE satellite. [24] The Central Valley, where a large portion of the California Aqueduct runs through, has been affected by the pumping of groundwater and subsequent land subsidence. [25] Farmers in and near the Central Valley have become reliant on groundwater especially with recent droughts impacting the amount of readily accessible surface water. [20] However, overuse of groundwater can cause irreversible damage. During the 2011-2017 California drought, a record high drought, groundwater and its storage capabilities in the San Joaquin Valley saw a sharp decline. [26] From October 2011 to September 2015 measurements made on groundwater levels in the San Joaquin Valley's aquifers recorded a loss of 14 km3/year, a total of 56 km3. [26] During this same period up to 1,000 mm of land subsidence was measured in the San Joaquin Valley. [26] Concerns around groundwater depletion have contributed to legislation to reduce the demand for groundwater and incentivize farmers to use sustainable irrigation practices. [20]

Measurement

Measurement of this subsidence is done in a few ways. Originally, subsidence was recorded based on land surveying, repeating the surveying, and along with monitoring compaction by recording the data from extensometers at multiple sites. Since then, Global Positioning Systems (GPS) has been used along with land surveying to record subsidence and compaction. [18] More recently, interferometric synthetic aperture radar (InSAR) has been used to monitor subsidence along with GPS. InSAR is being used to recreate maps to closely watch the progression of the land around the aqueduct. [27]

Consequences

Subsidence can put land, both private and public, at risk of infrastructure damage. Bridges, levees, roads, and groundwater wells are either at risk of damage or have been damaged already. With subsidence progression, underground aquifers could be at risk and water storage from them could be threatened. [27] Damage and sinking of the canal of the aqueduct has already occurred from subsidence which has made the canal less reliable. Capacity has been compromised due to damage to the canals and therefore has caused problems and delays with delivering the water across the state, as well as higher rates and costs for power and operation. [19]

A documentary about the decline of the United States' infrastructure, The Crumbling of America, [28] was commissioned by the U.S. A&E network in the late 2000s. The documentary is typically shown on the History television channel in the United States, although other educational broadcasters globally have shown it. It features the Clifton Court Forebay (a primary intake point for California Aqueduct) as a "strategic piece of California freshwater infrastructure" subject to shutdown for up to two years if struck by an earthquake of magnitude 7.5 or greater.

The aqueduct is featured in an episode of California's Gold with Huell Howser. [29]

See also

Related Research Articles

<span class="mw-page-title-main">Central Valley (California)</span> Flat valley that dominates central California

The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is 40–60 mi (60–100 km) wide and runs approximately 450 mi (720 km) from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It covers approximately 18,000 sq mi (47,000 km2), about 11% of California's land area. The valley is bounded by the Coast Ranges to the west and the Sierra Nevada to the east.

<span class="mw-page-title-main">San Joaquin River</span> Longest river of Central California, United States

The San Joaquin River is the longest river of Central California. The 366-mile (589 km) long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean. An important source of irrigation water as well as a wildlife corridor, the San Joaquin is among the most heavily dammed and diverted of California's rivers.

<span class="mw-page-title-main">Sacramento–San Joaquin River Delta</span> Inland river delta and estuary in Northern California

The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Northern California. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin rivers and lies just east of where the rivers enter Suisun Bay, which flows into San Francisco Bay, then the Pacific Ocean via San Pablo Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. Sacramento–San Joaquin Delta was designated a National Heritage Area on March 12, 2019. The city of Stockton is located on the San Joaquin River at the eastern edge of the delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2). Its population is around 500,000.

<span class="mw-page-title-main">Metropolitan Water District of Southern California</span> Regional wholesaler of water in Southern California

The Metropolitan Water District of Southern California is a regional wholesaler and the largest supplier of treated water in the United States. The name is usually shortened to "Met," "Metropolitan," or "MWD." It is a cooperative of fourteen cities, eleven municipal water districts, and one county water authority, that provides water to 19 million people in a 5,200-square-mile (13,000 km2) service area. It was created by an act of the California State Legislature in 1928, primarily to build and operate the Colorado River Aqueduct. Metropolitan became the first contractor to the State Water Project in 1960.

The South Bay Aqueduct is an aqueduct located in the eastern part of the San Francisco Bay Area. It conveys water from the Sacramento-San Joaquin Delta through over forty miles of pipelines and canals. It begins in north-eastern Alameda County on the California Aqueduct's Bethany Reservoir serving as the forebay. The aqueduct flows along the eastern and southern edges of the Livermore Valley. Then it flows through a series of tunnels to an end in the foothills of eastern San Jose, 5 miles (8 km) from downtown San Jose, California.

<span class="mw-page-title-main">Delta–Mendota Canal</span> Aqueduct in Central California

The Delta–Mendota Canal is a 117-mile-long (188 km) aqueduct in central California, United States. The canal was designed and completed in 1951 by the U.S. Bureau of Reclamation as part of the Central Valley Project. It carries freshwater to replace San Joaquin River water which is diverted into the Madera Canal and Friant-Kern Canal at Friant Dam.

<span class="mw-page-title-main">Castaic Dam</span> Embankment dam in Los Angeles County, California, United States

Castaic Dam is an embankment dam in northwestern Los Angeles County, California, in the unincorporated area of Castaic. Although located on Castaic Creek, a major tributary of the Santa Clara River, Castaic Creek provides little of its water. The lake is the terminus of the West Branch of the California Aqueduct, part of the State Water Project. The dam was built by the California Department of Water Resources and construction was completed in 1973. The lake has a capacity of 325,000 acre-feet (401,000,000 m3) and stores drinking water for the western portion of the Greater Los Angeles Area.

<span class="mw-page-title-main">San Luis Dam</span> Dam in Merced County, California

San Luis Dam, also known as B.F. Sisk Dam, is a major earth-filled dam in Merced County, California, which forms San Luis Reservoir, the largest off-stream reservoir in the United States. The dam and reservoir are located in the Diablo Range to the east of Pacheco Pass and about 10 miles (16 km) west of Los Banos. San Luis Dam, a jointly-owned state and federal facility, stores more than 2 million acre feet (2.5 km3) of water for the California State Water Project and the federal Central Valley Project. Although the dam is located in the valley of San Luis Creek, the majority of its water comes from man-made aqueducts which are supplied from other rivers in Northern California.

<span class="mw-page-title-main">California Department of Water Resources</span>

The California Department of Water Resources (DWR) is part of the California Natural Resources Agency and is responsible for the management and regulation of the State of California's water usage. The department was created in 1956 by Governor Goodwin Knight following severe flooding across Northern California in 1955, where they combined the Division of Water Resources of the Department of Public Works with the State Engineer's Office, the Water Project Authority, and the State Water Resources Board. It is headquartered in Sacramento.

<span class="mw-page-title-main">San Luis Reservoir</span> Lake in Merced County, California, United States of America

The San Luis Reservoir is an artificial lake on San Luis Creek in the eastern slopes of the Diablo Range of Merced County, California, approximately 12 mi (19 km) west of Los Banos on State Route 152, which crosses Pacheco Pass and runs along its north shore. It is the fifth largest reservoir in California. The reservoir stores water taken from the San Joaquin-Sacramento River Delta. Water is pumped uphill into the reservoir from the O'Neill Forebay which is fed by the California Aqueduct and is released back into the forebay to continue downstream along the aqueduct as needed for farm irrigation and other uses. Depending on water levels, the reservoir is approximately nine miles (14 km) long from north to south at its longest point, and five miles (8 km) wide. At the eastern end of the reservoir is the San Luis Dam, the fourth largest embankment dam in the United States, which allows for a total capacity of 2,041,000 acre-feet (2,518,000 dam3). Pacheco State Park lies along its western shores.

<span class="mw-page-title-main">California State Water Project</span> Flood control, energy production, and water conveyance infrastructure in the US

The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 27 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.

<span class="mw-page-title-main">North Bay Aqueduct</span> Aqueduct in northern California, US

The North Bay Aqueduct (NBA) is part of the California State Water Project that was built in two phases, Phase I (1967-1968) and Phase II (1985-1988). The aqueduct is 27.4 miles (44.1 km) long all in pipelines and serves Napa and Solano counties, California. The aqueduct provides water to about 500,000 residents in Solano and Napa.

The Peripheral Canal was a series of proposals starting in the 1940s to divert water from California's Sacramento River, around the periphery of the San Joaquin-Sacramento River Delta, to uses farther south. The canal would have attempted to resolve a problem with the quality of water pumped south. Pumps create such a powerful suction that the boundary between freshwater to saltwater has shifted inland, negatively affecting the environment. The pumps have increased by 5 to 7 million acre-feet the amount of water exported each year to the Central Valley and Southern California. However, the peripheral canal as proposed would have reduced the overall freshwater flow into the Delta and move the freshwater-saltwater interface further inland, causing damage to Delta agriculture and ecosystems.

<span class="mw-page-title-main">Friant-Kern Canal</span> Aqueduct in California

The Friant-Kern Canal is a 152 mi (245 km) aqueduct managed by the United States Bureau of Reclamation in Central California to convey water to augment irrigation capacity in Fresno, Tulare, and Kern counties. A part of the Central Valley Project, canal construction began in 1949 and was completed in 1951 at a cost of $60.8 million.

<span class="mw-page-title-main">Dos Amigos Pumping Plant</span> Water pumping plant in Merced County, California

The Dos Amigos Pumping Plant is a water pumping plant, constructed between 1963 and 1966 as part of the California State Water Project. It is able to withhold and transport water between Northern and Southern California through an approximately 444 mile aqueduct. It is located in Central California's San Joaquin Valley along Interstate 5, about 10 miles south of Los Banos in Merced County.

<span class="mw-page-title-main">Water in California</span> Water supply and distribution in the U.S. state of California

California's interconnected water system serves almost 40 million people and irrigates over 5,680,000 acres (2,300,000 ha) of farmland. As the world's largest, most productive, and potentially most controversial water system, it manages over 40 million acre-feet (49 km3) of water per year. Use of available water averages 50% environmental, 40% agricultural and 10% urban, though this varies considerably by region and between wet and dry years. In wet years, "environmental" water averages 61%, while in dry years it averages 41%, and can be even lower in critically dry years.

<span class="mw-page-title-main">Mokelumne Aqueduct</span> Bridge

The Mokelumne Aqueduct is a 95-mile (153 km) water conveyance system in central California, United States. The aqueduct is supplied by the Mokelumne River and provides water to 35 municipalities in the East Bay in the San Francisco Bay Area. The aqueduct and the associated dams, pipelines, treatment plants and hydroelectric system are owned and operated by the East Bay Municipal Utility District (EBMUD) and provide over 90 percent of the water used by the agency.

<span class="mw-page-title-main">Castaic Power Plant</span> Pumped-storage hydroelectric power station in Los Angeles County, California

Castaic Power Plant, also known as the Castaic Pumped-Storage Plant, is a seven unit pumped-storage hydroelectric plant, operated by the Los Angeles Department of Water and Power, which provides peak load power from the falling water on the West Branch of the California State Aqueduct. It is a cooperative venture between the LADWP and the Department of Water Resources of the State of California. An agreement between the two organizations was signed on September 2, 1966, for construction of the project.

Elderberry Forebay is a small reservoir in Los Angeles County, California, which serves as the pumping forebay of the Castaic Power Plant. It located at the upper end of the larger Castaic Lake and is separated from the lake by Elderberry Forebay Dam at its southern edge. Entering the northern end of the forebay is the west branch of the California Aqueduct, which connects the forebay to Pyramid Lake through the Angeles Tunnel.

The Central Valley in California subsides when groundwater is pumped faster than underground aquifers can be recharged. The Central Valley has been sinking (subsiding) at differing rates since the 1920s and is estimated to have sunk up to 28 feet. During drought years, the valley is prone to accelerated subsidence due to groundwater extraction. California periodically experiences droughts of varying lengths and severity.

References

  1. ↑ East Branch Aqueduct
  2. ↑ California Aqueduct
  3. ↑ U.S. Geological Survey – GNIS (January 19, 1981). "Feature Detail Report: Governor Edmund G Brown California Aqueduct". U.S. Department of the Interior. Retrieved March 19, 2009.
  4. ↑ DWR Public Affairs Office (2005). "State Water Project Today". Department of Water Resources, State of California. Archived from the original on June 10, 2007. Retrieved March 19, 2009.
  5. ↑ "SWP Facilities". water.ca.gov. Retrieved March 3, 2022.
  6. ↑ Simon, Matt (March 19, 2021). "Why Covering Canals With Solar Panels Is a Power Move". Wired. Archived from the original on May 4, 2021.
  7. ↑ "Edmonston Pumping Plant". Center for Land Use Interpretation. 2009. Archived from the original on July 24, 2008. Retrieved March 19, 2009.
  8. ↑ McKuin, Brandi; Zumkehr, Andrew; Ta, Jenny; Bales, Roger; Viers, Joshua H.; Pathak, Tapan; Campbell, J. Elliott (March 18, 2021). "Energy and water co-benefits from covering canals with solar panels". Nature Sustainability. 4 (7): 609–617. doi:10.1038/s41893-021-00693-8. S2CID   232273487.
  9. ↑ Carle, David (2004). Introduction to Water in California . Berkeley: University of California Press. pp.  97–99. ISBN   0-520-23580-0.
  10. ↑ "State Water Project in Santa Barbara County". Central Coast Water Authority. March 10, 2003. Archived from the original on December 11, 2009. Retrieved March 22, 2009.
  11. 1 2 3 "Facilities". California Department of Water Resources. April 7, 2019.
  12. 1 2 "Coastal Branch Brochure" (PDF). California Department of Water Resources.
  13. ↑ "Sacramento River Basin National Water Quality Assessment Program: Study Unit Description". United States Geological Survey . ca.water.usgs.gov. Retrieved July 26, 2009.
  14. ↑ "Restoring the San Joaquin River: Following an 18-year legal battle, a great California river once given up for dead is on the verge of a comeback". Natural Resources Defense Council. www.nrdc.org. September 17, 2007. Retrieved July 26, 2009.
  15. ↑ Gorelick, Ellen. "Tulare Lake". Tulare Historical Museum. www.tularehistoricalmueseum.org. Archived from the original on February 19, 2010. Retrieved July 26, 2009.
  16. ↑ "Delta Subsidence in California: The sinking heart of the State" (PDF). United States Geological Survey . ca.water.usgs.gov. Retrieved July 26, 2009.
  17. ↑ "Sacramento-San Joaquin River System, California". American Rivers. America's Most Endangered Rivers Report: 2009 Edition. Archived from the original on January 17, 2010. Retrieved July 26, 2009.
  18. 1 2 3 4 5 US Department of Commerce, National Oceanic and Atmospheric Administration. "What is subsidence?". oceanservice.noaa.gov. Retrieved April 1, 2022.
  19. 1 2 "CMUA". www.cmua.org. Retrieved April 1, 2022.
  20. 1 2 3 Stokstad, Erik (April 16, 2020). "Droughts highlighted California's unsustainable use of groundwater. Now, the state is trying to refill its aquifers". Science. Retrieved October 3, 2023.
  21. 1 2 3 Miller, Megan M.; Jones, Cathleen E.; Sangha, Simran S.; Bekaert, David P. (December 15, 2020). "Rapid drought-induced land subsidence and its impact on the California aqueduct". Remote Sensing of Environment. 251: 112063. doi:10.1016/j.rse.2020.112063. ISSN   0034-4257. S2CID   225017671.
  22. ↑ "California Aqueduct Subsidence | USGS California Water Science Center". ca.water.usgs.gov. Retrieved April 1, 2022.
  23. ↑ "California Aqueduct Subsidence Program". water.ca.gov. Retrieved May 2, 2022.
  24. ↑ Hartono, Naomi (April 5, 2022). "NASA Finds New Way to Monitor Underground Water Loss". NASA. Retrieved May 4, 2022.
  25. ↑ Jeanne, Pierre; Farr, Tom G.; Rutqvist, Jonny; Vasco, Donald W. (February 1, 2019). "Role of agricultural activity on land subsidence in the San Joaquin Valley, California". Journal of Hydrology. 569: 462–469. doi:10.1016/j.jhydrol.2018.11.077. ISSN   0022-1694. S2CID   135110152.
  26. 1 2 3 Ojha, Chandrakanta; Werth, Susanna; Shirzaei, Manoochehr (March 2019). "Groundwater Loss and Aquifer System Compaction in San Joaquin Valley During 2012–2015 Drought". Journal of Geophysical Research: Solid Earth. 124 (3): 3127–3143. doi:10.1029/2018JB016083. ISSN   2169-9313. PMC   6559157 . PMID   31218156.
  27. 1 2 Greicius, Tony (February 28, 2017). "NASA Data Show California's San Joaquin Valley Still Sinking". NASA. Retrieved April 1, 2022.
  28. ↑ "The Crumbling of America (2:49 introductory clip)". YouTube . Retrieved September 11, 2013.
  29. ↑ "California Aqueduct Special – California's Gold (001) – Huell Howser Archives at Chapman University". May 3, 2016.
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