The Los Angeles Aqueduct system, comprising the Los Angeles Aqueduct (Owens Valley aqueduct) and the Second Los Angeles Aqueduct, is a water conveyance system, built and operated by the
Los Angeles Department of Water and Power.
The Owens Valley aqueduct was designed and built by the city's water department, at the time named The Bureau of Los Angeles Aqueduct, under the supervision of the department's Chief Engineer
William Mulholland. The system delivers water from the
Owens River in the Eastern Sierra Nevada Mountains to
Los Angeles
Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the wor ...
,
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...
.
The aqueduct's construction was controversial from the start, as water diversions to Los Angeles eliminated the
Owens Valley as a viable farming community.
Clauses in the city's charter originally stated that the city could not sell or provide surplus water to any area outside the city, forcing adjacent communities to annex themselves into Los Angeles.
The aqueduct's infrastructure also included the completion of the
St. Francis Dam in 1926 to provide storage in case of disruption to the system.
The dam's collapse two years later killed at least 431 people, halted the rapid pace of annexation, and eventually led to the formation of the
Metropolitan Water District of Southern California to build and operate the
Colorado River Aqueduct to bring water from the
Colorado River
The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...
to
Los Angeles County
Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is th ...
.
The continued operation of the Los Angeles Aqueduct has led to public debate, legislation, and court battles over its environmental impacts on
Mono Lake and other ecosystems.
First Los Angeles Aqueduct
Construction
The aqueduct project began in 1905 when the voters of Los Angeles approved a bond for the 'purchase of lands and water and the inauguration of work on the aqueduct'. On June 12, 1907, a second bond was passed with a budget of to fund construction.
Construction began in 1908 and was divided into eleven divisions. The city acquired three limestone quarries, two
Tufa
Tufa is a variety of limestone formed when carbonate minerals precipitate out of water in unheated rivers or lakes. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits, which are known as traverti ...
quarries and it constructed and operated a cement plant in
Monolith, California which could produce 1,200 barrels of Portland cement per day. Regrinding mills were also built and operated by the city at the tufa quarries. To move 14 million ton-miles of freight, the city contracted with Southern Pacific to build a 118 mile long rail system from the Monolith mills to Olancha.
The number of men who were on the payroll the first year was 2,629 and this number peaked at 6,060 in May 1909. In 1910, employment dropped to 1,150 due to financial reasons but rebounded later in the year. Between 1911 and 1912 employment ranged from 2,800 to 3,800 workers. The number of laborers working on the aqueduct at its peak was 3,900.
[ Includes construction photos.] In 1913, the City of Los Angeles completed construction of the first Los Angeles Aqueduct.
Route
The aqueduct as originally constructed consisted of six storage reservoirs and of conduit. Beginning north of Black Rock Springs, the aqueduct diverts the
Owens River into an unlined canal to begin its journey south to the Lower San Fernando Reservoir.
This reservoir was later renamed the
Lower Van Norman Reservoir.
The original project consisted of of open unlined canal, of lined open canal, of covered concrete conduit, of concrete tunnels, steel siphons, of railroad track, two hydroelectric plants, three cement plants, of power lines, of telephone line, of roads
and was later expanded with the construction of the Mono Extension and the Second Los Angeles Aqueduct.
The aqueduct uses gravity alone to move the water and also uses the water to generate electricity, which makes it cost-efficient to operate.
Reactions by impacted communities
The construction of the Los Angeles Aqueduct effectively eliminated the Owens Valley as a viable farming community and eventually devastated the
Owens Lake ecosystem.
A group labeled the "San Fernando Syndicate" – including Fred Eaton, Mulholland,
Harrison Otis (the publisher of The
Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the ...
),
Henry Huntington (an executive of the Pacific Electric Railroad), and other wealthy individuals – were a group of investors who bought land in the
San Fernando Valley allegedly based on inside knowledge that the Los Angeles aqueduct would soon irrigate it and encourage development.
[ Although there is disagreement over the actions of the "syndicate" as to whether they were a "diabolical" cabal or only a group that united the Los Angeles business community behind supporting the aqueduct,] Eaton, Mulholland and others connected with the project have long been accused of using deceptive tactics and underhanded methods to obtain water rights and block the Bureau of Reclamation
The Bureau of Reclamation, and formerly the United States Reclamation Service, is a federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it applies to the oversight and opera ...
from building water infrastructure for the residents in Owens Valley.
By the 1920s, the aggressive pursuits of the water rights and the diversion of the Owens River precipitated the outbreak of violence known as the California water wars. Farmers in Owens Valley attacked infrastructure, dynamiting the aqueduct numerous times and opening sluice gates to divert the flow of water.
St. Francis Dam failure
In 1917, The Bureau of Los Angeles Aqueduct sought to build a holding reservoir to regulate flow, provide hydroelectric power, and storage in case of disruption to the aqueduct system. The initial site chosen was in Long Valley, east of the Owens River, but Eaton, who had bought up much of the valley in anticipation of the need for a reservoir, refused to sell the land at the price offered by Los Angeles. Mulholland then made the decision to move the reservoir to San Francisquito Canyon above what is now Santa Clarita, California. The resulting St. Francis Dam was completed in 1926 and created a reservoir capacity of 38,000 acre-feet (47,000,000 m3). On March 12, 1928, the dam catastrophically failed, sending a wall of water down the canyon, ultimately reaching the Pacific Ocean near Ventura and Oxnard, and killing at least 431 people. The resulting investigation and trial led to the retirement of William Mulholland as the head of the Los Angeles Bureau of Water Works and Supply in 1929. The dam failure is the worst man-made flood disaster in the US in the 20th century and the second largest single-event loss of life in California history after the 1906 San Francisco earthquake
At 05:12 Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (''Extreme''). High-intensity s ...
.
Mono Basin Extension
In an effort to find more water, the city of Los Angeles reached farther north. In 1930, Los Angeles voters passed a third bond to buy land in the Mono Basin and fund the Mono Basin extension. The extension diverted flows from the Rush Creek, Lee Vining Creek, Walker and Parker Creeks that would have flowed into Mono Lake. The construction of the Mono extension consisted of an intake at Lee Vining Creek, the Lee Vining conduit to the Grant Reservoir on Rush Creek, which would have a capacity of , the Mono Craters Tunnel to the Owens River and a second reservoir, later named Crowley Lake
Crowley Lake is a reservoir on the upper Owens River in southern Mono County, California, in the United States. Crowley Lake is south of Mammoth Lakes.
The lake was created in 1941 by the building of the Long Valley Dam by the Los Angeles D ...
with a capacity of in Long Valley at the head of the Owens River Gorge.
Completed in 1940, diversions began in 1941. The Mono Extension has a design capacity of of flow to the aqueduct; however, the flow was limited to due to the limited downstream capacity of the Los Angeles Aqueduct. Full appropriation of the water could not be met until the second aqueduct was completed in 1970.
The Mono Extension's impact on Mono Basin and litigation
Between 1940 and 1970, water exports through the Mono Extension averaged per year and peaked at in 1974. Export licenses granted by the State Water Resources Control Board (SWRCB) in 1974 increased exports to per year. These export levels severely impacted the region's fish habitat, lake level and air quality, which led to a series of lawsuits. The results of the litigation culminated with a SWRCB Decision to restore fishery protection (stream) flows to specified minimums, and raise Mono Lake to above sea level. The agreement limited further exports from the Mono Basin to per year.
Second Los Angeles Aqueduct
In 1956, the State Department of Water Resources reported that Los Angeles was only exporting of water of the available in the Owens Valley and Mono Basin. Three years later, the State Water Rights Board warned Los Angeles that they could lose rights to the water they were permitted for but not appropriating. Faced with the possible loss of future water supply, Los Angeles began the five-year construction of the aqueduct in 1965 at a cost US$89 million. Once the city received diversion permits, water exports jumped in 1970, adding 110,000 AF that year into the aqueduct system. By 1974, exports climbed to per year. Unlike the First Aqueduct which was built entirely by Public Works, the Second Los Angeles Aqueduct was primarily built on contract by various private construction firms including R.A. Wattson Co., Winston Bros., and the Griffith Co. The Los Angeles Department of Water and Power managed the project and performed some finishing construction on the Mojave conduit and Jawbone & Dove Spring pipelines.
Route
The aqueduct was designed to flow and begins at the Merritt Diversion Structure at the junction of the North and South Haiwee Reservoirs, south of Owens Lake, and runs roughly parallel to the first aqueduct. Water flows entirely by gravity from an elevation of at the Haiwee Reservoir through two power drops to an elevation of at the Upper Van Norman Reservoir.
The Second Aqueduct was not built as a single contiguous conduit. For design and construction purposes the aqueduct was divided into Northern and Southern sections and the two are connected by the San Francisquito Tunnels, which are part of the First Aqueduct.
The Northern Section carries water starting at the North Haiwee Reservoir through the Haiwee Bypass passing around the South Haiwee Reservoir. The flow then continues south through a series of pressure pipelines and concrete conduits where it connects up with the First Aqueduct at the North Portal of the Elizabeth Tunnel near the Fairmont Reservoir.
The San Francisquito Tunnels (which includes the Elizabeth Tunnel) has a flow capacity of and is large enough to handle the flow of both aqueducts. Once the combined flow reaches the penstocks above Power Plant #2, water is diverted into the Southern Section of the second aqueduct away through the Drinkwater Tunnel to the Drinkwater Reservoir.
The last segment of pipe, known as the Saugus Pipeline,[Includes maps and pictures] carries water south past Bouquet Canyon
Bouquet Canyon, also known as Hangman's Canyon and Dead Man's Canyon, is a canyon in Los Angeles County, California.
Description
Bouquet Canyon is one of many canyons branching from the Santa Clarita Valley in Los Angeles County, whose streams fe ...
, Soledad Canyon and Placerita Canyon in the city of Santa Clarita. From there it roughly parallels Sierra Highway before it enters Magazine Canyon towards the Terminal structure and Cascades. Water from the Terminal structure can then flow to either the Cascade or penstock to the Foothill Power Plant and into the Upper Van Norman Reservoir.
In addition to the construction in the Northern and Southern sections, improvements were also made to the lined canal between the Alabama Gates and the North Haiwee Reservoir in the Northern Section that consisted of adding sidewalls to both sides of the canal and the raising of overcrosses. This work increased the capacity of the lined canal from to cfs.
Second aqueduct's impact on the water system
The increased flows provided by the second aqueduct lasted only from 1971 through 1988. In 1974 the environmental consequences of the higher exports were first being recognized in the Mono Basin and Owens Valley. This was followed by a series of court ordered restrictions imposed on water exports, which resulted in Los Angeles losing water. In 2005, the Los Angeles Urban Water Management Report reported that 40–50% of the aqueduct's historical supply is now devoted to ecological resources in Mono and Inyo counties.
Influence on Los Angeles and the county
Between 1909 and 1928, the city of Los Angeles grew from 61 square miles to 440 square miles. This was due largely to the aqueduct, and the city's charter was worded such that it stated the City of Los Angeles could not sell or provide surplus water to any area outside the city.
Outlying areas relied on wells and creeks for water and, as they dried up, the people in those areas realized that if they were going to be able to continue irrigating their farms and provide themselves domestic water, they would have to annex themselves to the City of Los Angeles.
Growth was so rapid that it appeared as if the city of Los Angeles would eventually assume the size of the entire county. William Mulholland continued adding capacity to the aqueduct, building the St. Francis Dam that would impound the waters creating the San Francisquito Reservoir, filed for additional water on the Colorado River and he began sending engineers and miners to clear the heading at the San Jacinto Tunnel that he knew was key to the construction of the Colorado River Aqueduct.
The aqueduct's water provided developers with the resources to quickly develop the San Fernando Valley and Los Angeles through World War II. Mulholland's role in the vision and completion of the aqueduct and the growth of Los Angeles into a large metropolis is recognized with the William Mulholland Memorial Fountain, built in 1940 at Riverside Drive and Los Feliz Boulevard in Los Feliz. Mulholland Drive and Mulholland Dam are both named after him.
Many more cities and unincorporated areas would likely have annexed into the city of Los Angeles if the St. Francis Dam had not collapsed. The catastrophic failure of the St. Francis Dam in 1928 killed an estimated 431 people, flooded parts of Santa Clarita, and devastated much of the Santa Clara River Valley in Ventura County.
The failure of the dam raised the question in a number of people's minds whether the city had engineering competence and capability to manage such a large project as the Colorado River Aqueduct despite the fact that they had built the Los Angeles Aqueduct. After the collapse, the pace of annexation came to a rapid halt when eleven nearby cities including Burbank, Glendale, Pasadena, Beverly Hills, San Marino, Santa Monica, Anaheim, Colton, Santa Ana, and San Bernardino decided to form the Metropolitan Water District with Los Angeles. The city's growth following the formation of the MWD would be limited to 27.65 square miles.
In popular culture
* Saugus High School derives the name of its daily newsletter, The Pipeline, from an exposed portion of the first aqueduct that passes southwest of the school's property.
* San Francisquito Canyon and DWP Power House #1 are featured in ''Visiting... with Huell Howser'' Episode 424.
California Historical Landmark – Cascades
The Cascades, which was completed on November 5, 1913, is located near the intersection of Foothill Boulevard and Balboa Boulevard, four miles northwest of San Fernando. It was designated as a California Historical Landmark
A California Historical Landmark (CHL) is a building, structure, site, or place in California that has been determined to have statewide historical landmark significance.
Criteria
Historical significance is determined by meeting at least one of ...
on July 28, 1958.
Gallery
File:Owens-river-diversion-gates.jpg, Diversion gates that control inflow to the Lower Owens River
File:La-aqueduct-intake.jpg, Intake where water is diverted from the Owens River
File:Water-entering-los-angeles-aqueduct.jpg, Water entering the aqueduct at its northern terminus
file:LA Aqueduct Antelope Valley.jpg, The Los Angeles Aqueduct in Antelope Valley
The Antelope Valley is located in northern Los Angeles County, California, and the southeast portion of Kern County, California, and constitutes the western tip of the Mojave Desert. It is situated between the Tehachapi, Sierra Pelona, and t ...
file:Cat45-mojave.jpg, Holt tractors at work during construction of the first aqueduct in 1909
file:LAAqueductUnlined2.jpg, Unlined section of the Los Angeles Aqueduct, just south of Manzanar, near US Highway 395
file:LA Aqueduct Cascades.jpg, The Terminal Structure and penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is inherited from the earlier technology of mill ponds and watermills. ...
above and alongside the new Cascades on the Los Angeles Aqueduct near Newhall Pass
File:Department Surveying LAA2.jpg, Department Surveyors plotting topography for Second Los Angeles Aqueduct.
File:Fairmont Mill.jpg, Fairmont Mill ruins on the east side of Fairmont Butte
Fairmont Butte is a butte of volcanic origins in the Antelope Valley just west of the City of Lancaster, California in Los Angeles County. Summit elevation is 3,130 feet above sea level. Parts of Fairmont Butte are situated within the boundaries o ...
. This mill was one of three that the city ran to produce cement for the Los Angeles Aqueduct.
File:LAA Historical Water (1913 to 2011).jpg, Chart showing water imports through the Los Angeles Aqueduct system from 1913 through 2011.
File:Shangri-La Estates.png, Shangri-La Estates in Ridgecrest, CA was built to provide temporary housing for personnel during the construction of the SLAA.
File:Construction of the Terminal Structure above the Second Los Angeles Aqueduct cascade.png, Forming in place for Terminal Structure above the SLAA cascade.
File:Pouring Concrete for the Terminal Structure above the Second Los Angeles Aqueduct cascade.png, Pouring concrete for Terminal Structure above the SLAA cascade.
File:SLAA Conduit Construction.jpg, Construction of the Second Los Angeles Aqueduct.
File:SLAA Finished concrete box conduit.jpg, Finished concrete box on the Los Angeles Aqueduct.
See also
* American Water Landmark
* California Aqueduct
* Colorado River Aqueduct
* State Water Project
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 ...
* Owensmouth
Owensmouth, California, was a town founded in 1912 in the western part of the San Fernando Valley. Owensmouth joined the city of Los Angeles in 1917, and was renamed Canoga Park on March 1, 1931. Owensmouth was named for the 1913 Owens River aq ...
References
Notes
Further reading
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External links
LADWP: official Los Angeles Aqueduct website
UCLA: Los Angeles Aqueduct Digital Platform
Los Angeles Aqueduct Landscape Atlas
Mono Lake Committee Website
LADWP: History page on William Mulholland
Los Angeles Aqueduct Slideshow
The William Mulholland Memorial Fountain
Image of workers making repairs on a damaged section of the Los Angeles Aqueduct in No-Name Canyon, Inyo County vicinity, [about 1927
">bout 1927">Image of workers making repairs on a damaged section of the Los Angeles Aqueduct in No-Name Canyon, Inyo County vicinity, [about 1927
Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the ...
Photographic Archive (Collection 1429). UCLA Library Special Collections, Charles E. Young Research Library, University of California, Los Angeles.
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{{Generating stations in California, state=autocollapse
Aqueducts in California
Interbasin transfer
Water in California
Aqueduct
Aqueduct
History of the San Fernando Valley
History of Inyo County, California
History of Mono County, California
Owens Valley
Sierra Nevada (United States)
Transportation buildings and structures in Inyo County, California
Transportation buildings and structures in Kern County, California
Transportation buildings and structures in Los Angeles County, California
Transportation buildings and structures in Mono County, California
Buildings and structures in the San Fernando Valley
Historic American Buildings Survey in California
Historic American Engineering Record in California
Historic Civil Engineering Landmarks
Los Angeles Historic-Cultural Monuments
1913 establishments in California
Hydroelectric power plants in California