L.A.’s Growing Access to Water
03/29/2015 dcoffin Add Comment
This is Part I of a series describing L.A.’s water supply problem and the policies that produced it.
To summarize the city’s first 75 years of access to water with one word that word would be ‘remarkable’. During that period The City of Los Angeles saw its access to water supply grow from 51,402 to 716,951 acre-feet per year by 1984. Acquiring that growth of supply took luck, engineering, tenacity, foresight, bold investments, deception, exploitation, dishonesty, and friends in high places to make it happen.
The following is a summary of the main water projects that brought water to the City of Los Angeles in order of time completed. The numbers below are close but inexact because the data came from various agencies and they did not always compare and earlier data is quite old so this became a challenge for me to try and summarize. However they were close and are accurate enough to develop a picture of an extraordinary period of water supply growth that enabled the city to grow from 577,000 people in 1920 to 3.9 million today.
Los Angeles River
In 1887 the city waterworks was only a series of ditches, pipes, and ferris wheel like contraptions that plucked water out of the Los Angeles River. The slow moving 71 cu ft/sec flows of water in the Los Angeles River clearly limited the city’s growth.
With only 51,000 af/y of water available to the city and recognizing that the Los Angeles City Water Company lacked the means and desire to develop new sources, the city council of Los Angeles directed the city engineer Fred Eaton to draw up plans to acquire the private waterworks and create a municipal waterworks. Along with the acquisition, the city also acquired a pivotal figure in the development of the city's future water supply, the company’s superintendent, William Mulholland.
Mulholland immediately expanded the use of water meters in the city to extend supplies but he asserted that the city could not grow beyond 220,000 people without more water. To grow, the city would need to find new sources of water outside of the city. Mulholland surveyed potential sources of water at Piru Creek, Kern, Santa Ana, Mojave, and San Luis Rey rivers but eventually ruled them all out. Separately, Eaton had been traveling the Owens Valley and had seen a pair of private surveys that determined that it should be technically possible to construct a canal to bring the waters of the Owens Valley to Los Angeles. Eaton and Mulholland began promoting the idea and soon Eaton had the role as the city’s agent to buy up Owens Valley properties for the water rights.
Over time the Los Angeles river no longer served as a viable source of water. Instead as the city grew and development overtook open land and agriculture the rivers only purpose would be a means to channel storm water and treated waste water into the ocean.
LA Aqueduct (Completed 1913)
In response to Mulholland's warning that the L.A. River was incapable of supporting more than 220,000 people, L.A. City voters approved a series of bonds to purchase Owens Valley properties and begin construction of the aqueduct. Construction on the 235 mile long aqueduct began in 1908 and was completed in November of 1913. The aqueduct had a capacity of 486 cu ft/sec or about 352,000 af/y and for the first time, the city was receiving a reliable supply of water that would average about 216,000 af/y per year.
Groundwater supply for the city of Los Angeles from 1916 through 1958 averaged about 56,360 af/y per year which increased L.A. Supply to an average 270,000 af/y.
Mono Extension (Completed 1941)
L.A.'s Growing Supply - 1913 to 1984
With a rapidly growing population the city passed another bond in 1930 to extend the aqueduct up the Mono Basin and capture waters from Rush Creek and Lee Vining Creek. The Mono Extension was completed in 1940 with diversions beginning the following year. While the Mono extension had a capacity of 400 cfs, exports were limited to 128 cfs because the aqueduct downstream had finally reached it's capacity. The city for the time being would have sufficient supplies once it began receiving Colorado River water the following year. Along with pumping in the Owens Valley, the aqueducts flows increased L.A.’s supply to an average of 314,000 af/y.
Metropolitan Water District – Colorado River Aqueduct (Completed 1941)
As a member agency of the Metropolitan Water District the city is permitted to buy water from the MWD. The Colorado River Aqueduct was completed in 1941. Los Angeles buys imported water from the Metropolitan Water District at a higher cost than city owned water. Between 1941 and 1984 CRA supplies to L.A. averaged 45,000 af and along with increased local groundwater pumping together they would eventually push L.A.’s total supply to an average of 448,000 af/y.
Second Los Angeles Aqueduct (Completed 1970)
Control Gorge - Mono Extension.
Library of Congress HAER CA-298-K-6
The aqueduct’s 422 cubic foot/second capacity was not enough to meet the 590,000 af/y the city was licensed for and this bottleneck became an issue when the State Department of Water Resources reported in 1956 that the city was only exporting 320,000 af/y. In 1959 the DWR told the city it would lose its rights to the water it was permitted for if it did not appropriate it.
Faced with this possible loss, the city then began construction of the Second Los Angeles aqueduct in 1965 and completed it in 1970. The aqueduct added 290 cu ft/s capacity and mostly paralleled the first aqueduct until it reaches the Antelope Valley where it take shorter route across the valley floor. Both 1st and 2nd aqueducts join together at the Elizabeth Tunnel complex and separate again at the south end of the complex.
In 1974 the city received licenses to divert up to 167,000 af/y annually from Mono and Owens pumping would add 160,000 af/y. Second Los Angeles Aqueduct increased L.A.’s supply to an average of 591,000 af/y per year.
Metropolitan Water District – State Water Project (Completed 1971)
The State of California completed construction of the California Aqueduct in 1971. The California Aqueduct delivers waters from the Sacramento Delta to Southern California. As a member agency of the Metropolitan Water District, the City of Los Angeles has access to SWP imports. L.A.’s supply peaked in 1984 at 716,951 af/y.
As the supply grew it seemed that there was no limits to the city’s growth. But water in California is a zero-sum game. In Part II I'll describe the loss of access that will take L.A.'s city owned supply back to pre-1940's levels.
Recommended reading: ‘Water and Power’ (1982) by William L. Kahrl which tells L.A.'s water story from the beginning in 1885 through the mid eighties and ‘Owens Valley Revisited’ (2007) by Gary D. Libecap which focuses on the original negotiations between the Eaton, the city and Owens Valley farmers between 1905 and 1938 and the litigations that took place after the publication of Kahrl's book. L.A.'s Water Plans Aqueduct, Colorado River Aqueduct, First Aqueduct, Mono Basin, Owens Valley, Second Aqueduct, State Water Project
Construction of 2nd Aqueduct
at Terminal Hill.