Metropolitan Water District of Southern California
Encyclopedia
The Metropolitan Water District of Southern California is the largest supplier of treated water in the US. The name is usually shortened to the "Metropolitan Water District" or simply "MWD". It is a cooperative
of 14 cities and 12 municipal water districts that indirectly provides water to 18 million people in its 5200 square miles (13,467.9 km²) service area. It was created by an act of the California Legislature in 1928, primarily to build and operate the Colorado River Aqueduct
. MWD became the first (and largest) contractor to the State Water Project in 1960.
It includes parts of Los Angeles
, Orange
, San Diego
, Riverside
, San Bernardino
and Ventura
counties. The district covers primarily the coastal and most heavily populated portions of Southern California
; however large portions of San Diego, San Bernardino and Riverside counties are located outside of its service area.
The MWD headquarters is located at 700 North Alameda Street in downtown Los Angeles, adjacent to Union Station
.
. The MWD is governed by a board of 37 directors whose powers and functions are specified in the 1927 authorization act. This board was in charge of issuing bonds and financing their repayment by selling water to member agencies. In the early years, revenue from water sales was too low, so MWD also collected taxes that ranged from 0.25 to 0.50 percent of assessed value. Ninety percent of the cost of the aqueduct has been paid for by the taxpayers. In 1929 the district was set up with an area of 600 square miles (1,554 km²) and served a population of around 1,600,000 in 13 cities.
During the aqueduct's first five years of service from 1941 to 1946 it delivered an average of about 27000 acre.ft of water, making use of less than two percent of its capacity. Only one pump at each lift, operating from one to six months out of the year, was needed to meet all the demands made on the system. At this time due to availability of ground water, less than ten percent of the Colorado River Aqueduct's capacity was used, only 178000 acre.ft of water.
With too much water and too little revenue, MWD's directors searched for new sources of demand. They found a semi-willing partner in the San Diego County Water Authority, which joined MWD as its first wholesale member agency in 1946. SDCWA was formed in 1944 to facilitate joining MWD, but did not do so until those opposed (mostly because of resentment of Los Angeles's dominance of MWD) were defeated by those in favor (FDR ordered the Navy to connect SDCWA to MWD; after WW2 ended, dwindling supplies did the rest of the job). SDCWA got its first deliveries in 1947 and was buying half of MWD's water by 1949. The SDCWA annexation broke two traditions at MWD: Member agencies had previously been cities (SDCWA was a water wholesaler) in the south coast basin (SDCWA was south of the basin). The next "break" came in 1950, when Pomona MWD (now Three Valleys MWD) joined MWD. Since Pomona was a largely agricultural member agency, MWD was no longer selling water for "domestic use".
In 1952, MWD began a 200 million dollar program to bring the Colorado River Aqueduct to its full capacity of 1212000 acre.ft annually. The Colorado River Aqueduct added six pumps to the original three at each of its five pumping stations. CRA pumping expanded from about 16500 acre.ft of water in 1950 to about 1029000 acre.ft by 1960. On August 9, 1962, the MWD set an all-time delivery record of 1,316,000,000 gallons of water in just a 24-hour period.
Met's additional supplies and easier rules of entry facilitated an expansion through annexation of large areas of low populations: The eight MWDs that joined from 1946 to 1955 added 200 percent to Met's service area but only 75 percent to Met's population served. By 1965, Met had 13 cities and 13 municipal water districts as members. It covered more than 4500 square miles (11,654.9 km²) in the counties of Los Angeles, Ventura, Orange, San Diego, Riverside, and San Bernardino—and served some 10,000,000 people.
As of 2008 Met has 14 cities and 12 municipal water districts (San Fernando joined in 1973; MWDOC and Coastal MWD merged in 2001) and provides purified drinking water to nearly 18,000,000 people.
On paper, Metropolitan should get about 2 mafy (million acre feet per year) from the State Water Project and 1.35 mafy from the Colorado River Aqueduct
. In the 20 years to 2004, Met got about 700 tafy from the SWP and 1.2 mafy from the CRA. Met projected SWP deliveries of 1.35-1.5 mafy in 2004, but (as of June 2009) problems with pumping from the Delta have cast doubt on this forecast.
The State Water Project moves water from the Sacramento-San Joaquin River Delta, via the California Aqueduct
to Castaic Lake
.
The Colorado River Aqueduct
begins at Lake Havasu
, which is behind Parker Dam
and ends at Lake Mathews
.
The Inland Feeder
project adds a direct tunnel and pipeline connection from Silverwood Lake to Diamond Valley Lake and is scheduled for completion in 2010.
The MWD maintains three major water reservoirs. One is Lake Mathews
located in southwest Riverside, California, with a capacity of 182000 acre.ft of water. Another is Lake Skinner
located south of Hemet in Riverside County, its capacity is 44,000 AF of water. Diamond Valley Lake
is their third and newest reservoir, with a capacity of 810,000 AF of water. As of November 11, 2008, it was 55% full. Once it is completely filled, the capacity will be twice as large as that of Castaic Lake
, the next largest reservoir in Southern California maintained by the state Department of Water Resources.
The water source for these reservoirs comes from the Colorado River Aqueduct which is first pumped 125 miles (201.2 km) uphill through a series of five pumping plants approaching Chiriaco Summit, then 117 miles (188.3 km) downhill towards Los Angeles.
The MWD partly funded the Brock Reservoir
project with $28.6 million. In return for their contribution, California can each use 100000 acre.ft of water starting in 2016.
They collectively filter water for more than 17 million Southern Californians. The MWD employs over 1,800 people to maintain and do research at these facilities, including scientists specializing in chemistry, microbiology, and limnology (the study of lakes and rivers).
Every year trained scientists and technicians perform more than 320,000 analytical tests on more than 50,000 samples. Metropolitan Water District has various EPA Environmental Protection Agency approved methods used to for the detection of bacteria, viruses, protozoan parasites, chemical contaminants and toxins.
Cooperative
A cooperative is a business organization owned and operated by a group of individuals for their mutual benefit...
of 14 cities and 12 municipal water districts that indirectly provides water to 18 million people in its 5200 square miles (13,467.9 km²) service area. It was created by an act of the California Legislature in 1928, primarily to build and operate the Colorado River Aqueduct
Colorado River Aqueduct
The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...
. MWD became the first (and largest) contractor to the State Water Project in 1960.
It includes parts of Los Angeles
Los Angeles County, California
Los Angeles County is a county in the U.S. state of California. As of 2010 U.S. Census, the county had a population of 9,818,605, making it the most populous county in the United States. Los Angeles County alone is more populous than 42 individual U.S. states...
, Orange
Orange County, California
Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...
, San Diego
San Diego County, California
San Diego County is a large county located in the southwestern corner of the US state of California. Hence, San Diego County is also located in the southwestern corner of the 48 contiguous United States. Its county seat and largest city is San Diego. Its population was about 2,813,835 in the 2000...
, Riverside
Riverside County, California
Riverside County is a county in the U.S. state of California. One of 58 California counties, it covers in the southern part of the state, and stretches from Orange County to the Colorado River, which forms the state border with Arizona. The county derives its name from the city of Riverside,...
, San Bernardino
San Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
and Ventura
Ventura County, California
Ventura County is a county in the southern part of the U.S. state of California. It is located on California's Pacific coast. It is often referred to as the Gold Coast, and has a reputation of being one of the safest populated places and one of the most affluent places in the country...
counties. The district covers primarily the coastal and most heavily populated portions of Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
; however large portions of San Diego, San Bernardino and Riverside counties are located outside of its service area.
The MWD headquarters is located at 700 North Alameda Street in downtown Los Angeles, adjacent to Union Station
Union Station (Los Angeles)
Los Angeles Union Station is the main railway station in Los Angeles, California. The station has rail services by Amtrak and Amtrak California and Metrolink; light rail/subways are the Metro Rail Red Line, Purple Line, Gold Line. Bus rapid transport runs on the Silver Line...
.
History
The Metropolitan Water District was formed in 1928, to build and operate a means to import water from the Colorado River to southern California: the Colorado River AqueductColorado River Aqueduct
The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...
. The MWD is governed by a board of 37 directors whose powers and functions are specified in the 1927 authorization act. This board was in charge of issuing bonds and financing their repayment by selling water to member agencies. In the early years, revenue from water sales was too low, so MWD also collected taxes that ranged from 0.25 to 0.50 percent of assessed value. Ninety percent of the cost of the aqueduct has been paid for by the taxpayers. In 1929 the district was set up with an area of 600 square miles (1,554 km²) and served a population of around 1,600,000 in 13 cities.
During the aqueduct's first five years of service from 1941 to 1946 it delivered an average of about 27000 acre.ft of water, making use of less than two percent of its capacity. Only one pump at each lift, operating from one to six months out of the year, was needed to meet all the demands made on the system. At this time due to availability of ground water, less than ten percent of the Colorado River Aqueduct's capacity was used, only 178000 acre.ft of water.
With too much water and too little revenue, MWD's directors searched for new sources of demand. They found a semi-willing partner in the San Diego County Water Authority, which joined MWD as its first wholesale member agency in 1946. SDCWA was formed in 1944 to facilitate joining MWD, but did not do so until those opposed (mostly because of resentment of Los Angeles's dominance of MWD) were defeated by those in favor (FDR ordered the Navy to connect SDCWA to MWD; after WW2 ended, dwindling supplies did the rest of the job). SDCWA got its first deliveries in 1947 and was buying half of MWD's water by 1949. The SDCWA annexation broke two traditions at MWD: Member agencies had previously been cities (SDCWA was a water wholesaler) in the south coast basin (SDCWA was south of the basin). The next "break" came in 1950, when Pomona MWD (now Three Valleys MWD) joined MWD. Since Pomona was a largely agricultural member agency, MWD was no longer selling water for "domestic use".
In 1952, MWD began a 200 million dollar program to bring the Colorado River Aqueduct to its full capacity of 1212000 acre.ft annually. The Colorado River Aqueduct added six pumps to the original three at each of its five pumping stations. CRA pumping expanded from about 16500 acre.ft of water in 1950 to about 1029000 acre.ft by 1960. On August 9, 1962, the MWD set an all-time delivery record of 1,316,000,000 gallons of water in just a 24-hour period.
Met's additional supplies and easier rules of entry facilitated an expansion through annexation of large areas of low populations: The eight MWDs that joined from 1946 to 1955 added 200 percent to Met's service area but only 75 percent to Met's population served. By 1965, Met had 13 cities and 13 municipal water districts as members. It covered more than 4500 square miles (11,654.9 km²) in the counties of Los Angeles, Ventura, Orange, San Diego, Riverside, and San Bernardino—and served some 10,000,000 people.
As of 2008 Met has 14 cities and 12 municipal water districts (San Fernando joined in 1973; MWDOC and Coastal MWD merged in 2001) and provides purified drinking water to nearly 18,000,000 people.
Water sources
Colorado River Aqueduct
The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...
. In the 20 years to 2004, Met got about 700 tafy from the SWP and 1.2 mafy from the CRA. Met projected SWP deliveries of 1.35-1.5 mafy in 2004, but (as of June 2009) problems with pumping from the Delta have cast doubt on this forecast.
The State Water Project moves water from the Sacramento-San Joaquin River Delta, via the California Aqueduct
California Aqueduct
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. The Department of Water Resources operates and maintains the...
to Castaic Lake
Castaic Lake
Castaic Lake is an artificial lake on Castaic Creek formed by Castaic Dam, in northwestern Los Angeles County, California, near the town of Castaic. The lake with a surface elevation of approximately above sea level is the terminus of the West Branch of the California Aqueduct, though some comes...
.
The Colorado River Aqueduct
Colorado River Aqueduct
The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...
begins at Lake Havasu
Lake Havasu
Lake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona. Lake Havasu City sits on the lake's eastern shore. The lake has a capacity of . The concrete arch dam was built by the United States Bureau of Reclamation between 1934 and 1938...
, which is behind Parker Dam
Parker Dam
Parker Dam is a concrete arch-gravity dam that crosses the Colorado River downstream of Hoover Dam. Built between 1934 and 1938 by the Bureau of Reclamation, it is high, of which are below the riverbed, making it "the deepest dam in the world". The dam's primary functions are to create a...
and ends at Lake Mathews
Lake Mathews
Lake Mathews is a large reservoir in Riverside County, California, located in the foothills of the Santa Ana Mountains. It is the western terminus for the Colorado River Aqueduct that provides much of the water used by the cities and water districts of the Metropolitan Water District of Southern...
.
The Inland Feeder
Inland Feeder
The Inland Feeder is a high capacity water conveyance system that connects the California State Water Project to the Colorado River Aqueduct and Diamond Valley Lake...
project adds a direct tunnel and pipeline connection from Silverwood Lake to Diamond Valley Lake and is scheduled for completion in 2010.
Reservoirs
The Metropolitan Water District of Southern California reservoirs store fresh water for use in Los Angeles, Orange, Ventura, Riverside, San Bernardino, and San Diego counties. These reservoirs were built specifically to preserve water during times of drought, and are in place for emergencies uses such as earthquake, floods or other events.The MWD maintains three major water reservoirs. One is Lake Mathews
Lake Mathews
Lake Mathews is a large reservoir in Riverside County, California, located in the foothills of the Santa Ana Mountains. It is the western terminus for the Colorado River Aqueduct that provides much of the water used by the cities and water districts of the Metropolitan Water District of Southern...
located in southwest Riverside, California, with a capacity of 182000 acre.ft of water. Another is Lake Skinner
Lake Skinner
Lake Skinner is a large reservoir in western Riverside County, California, located at the foot of Bachelor Mountain in the Auld Valley, approximately 10 miles northeast of Temecula...
located south of Hemet in Riverside County, its capacity is 44,000 AF of water. Diamond Valley Lake
Diamond Valley Lake
The embankment required of crushed rock. An on-site crushing plant crushed and processed over 14 million tons of rock in 20 months to supply the dam's materials. The cut-off wall, which consists of a thick plastic concrete mix constructed through the weathered portion of bedrock, varies in depth...
is their third and newest reservoir, with a capacity of 810,000 AF of water. As of November 11, 2008, it was 55% full. Once it is completely filled, the capacity will be twice as large as that of Castaic Lake
Castaic Lake
Castaic Lake is an artificial lake on Castaic Creek formed by Castaic Dam, in northwestern Los Angeles County, California, near the town of Castaic. The lake with a surface elevation of approximately above sea level is the terminus of the West Branch of the California Aqueduct, though some comes...
, the next largest reservoir in Southern California maintained by the state Department of Water Resources.
The water source for these reservoirs comes from the Colorado River Aqueduct which is first pumped 125 miles (201.2 km) uphill through a series of five pumping plants approaching Chiriaco Summit, then 117 miles (188.3 km) downhill towards Los Angeles.
The MWD partly funded the Brock Reservoir
Brock Reservoir
Brock Reservoir is a man-made reservoir located near Gordons Well, California. The reservoir consists of two basins that can hold a combined total of of water. It holds water from the All-American Canal until it can be used for nearby agriculture....
project with $28.6 million. In return for their contribution, California can each use 100000 acre.ft of water starting in 2016.
Purification and treatment
The Metropolitan Water District (MWD) operates five treatment plants:- Robert B. Diemer Treatment Plant in Yorba Linda, one of the largest in the country
- Joseph Jensen Treatment Plant in Granada Hills
- Henry J. Mills Treatment Plant in RiversideRiverside, CaliforniaRiverside is a city in Riverside County, California, United States, and the county seat of the eponymous county. Named for its location beside the Santa Ana River, it is the largest city in the Riverside-San Bernardino-Ontario metropolitan area of Southern California, 4th largest inland California...
- Robert A. Skinner Treatment Plant in WinchesterWinchester, CaliforniaWinchester is a census-designated place in Riverside County, California, USA. As of the 2010 census, the CDP had a total population of 2,534, up from 2,155 at the 2000 census....
- F.E. Weymouth Treatment Plant, a 58800 square feet (5,462.7 m²) facility in La VerneLa Verne, CaliforniaLa Verne is a city in Los Angeles County, California, United States. The population was 31,063 at the 2010 census, down from 31,638 at the 2000 census.-History:...
They collectively filter water for more than 17 million Southern Californians. The MWD employs over 1,800 people to maintain and do research at these facilities, including scientists specializing in chemistry, microbiology, and limnology (the study of lakes and rivers).
- The first step is primary disinfection, where the water is mixed with chlorine. Several of Metropolitan's treatment plants are now using ozone instead of chlorine as a primary disinfectant.
- The second step is rapid mixing chemicals such as ferric chloride and organic polymers to neutralize particles to allow them to combine.
- After being neutralized the water goes through flocculation; this stage unites the neutralized particles to form larger clumps of particles. The larger particles settle out of the water in the sedimentation process and any of the remaining particles are later removed through the filtration process.
- Next, more chlorine is added to the water to disinfect and prevent any illness due to water-borne pathogens.
- Lastly, ammonia is added to the water to react with the chlorine to form chloramines. Cloramines are used to maintain a residual disinfectant throughout the water distribution system. Sodium hydroxide is also added to adjust the pH level to protect the pipes and plumbing fixtures and fluoride is added to the water to help prevent dental carries in children.
Every year trained scientists and technicians perform more than 320,000 analytical tests on more than 50,000 samples. Metropolitan Water District has various EPA Environmental Protection Agency approved methods used to for the detection of bacteria, viruses, protozoan parasites, chemical contaminants and toxins.
Members
MWD list of member agencies- City of AnaheimAnaheim, CaliforniaAnaheim is a city in Orange County, California. As of the 2010 United States Census, the city population was about 365,463, making it the most populated city in Orange County, the 10th most-populated city in California, and ranked 54th in the United States...
- City of Beverly HillsBeverly Hills, CaliforniaBeverly Hills is an affluent city located in Los Angeles County, California, United States. With a population of 34,109 at the 2010 census, up from 33,784 as of the 2000 census, it is home to numerous Hollywood celebrities. Beverly Hills and the neighboring city of West Hollywood are together...
- City of BurbankBurbank, CaliforniaBurbank is a city in Los Angeles County in Southern California, United States, north of downtown Los Angeles. The estimated population in 2010 was 103,340....
- City of ComptonCompton, CaliforniaCompton is a city in southern Los Angeles County, California, United States, southeast of downtown Los Angeles. The city of Compton is one of the oldest cities in the county and on May 11, 1888, was the eighth city to incorporate. The city is considered part of the South side by residents of Los...
- City of FullertonFullerton, CaliforniaFullerton is a city located in northern Orange County, California. As of the 2010 census, the city had a total population of 135,161.It was founded in 1887 by George and Edward Amerige and named for George H. Fullerton, who secured the land on behalf of the Atchison, Topeka and Santa Fe Railway...
- City of GlendaleGlendale, CaliforniaGlendale is a city in Los Angeles County, California, United States. As of the 2010 Census, the city population is 191,719, down from 194,973 at the 2000 census. making it the third largest city in Los Angeles County and the 22nd largest city in the state of California...
- City of Long BeachLong Beach, CaliforniaLong Beach is a city situated in Los Angeles County in Southern California, on the Pacific coast of the United States. The city is the 36th-largest city in the nation and the seventh-largest in California. As of 2010, its population was 462,257...
- City of Los AngelesLos Angeles, CaliforniaLos Angeles , with a population at the 2010 United States Census of 3,792,621, is the most populous city in California, USA and the second most populous in the United States, after New York City. It has an area of , and is located in Southern California...
- City of PasadenaPasadena, CaliforniaPasadena is a city in Los Angeles County, California, United States. Although famous for hosting the annual Rose Bowl football game and Tournament of Roses Parade, Pasadena is the home to many scientific and cultural institutions, including the California Institute of Technology , the Jet...
- City of San FernandoSan Fernando, CaliforniaSan Fernando is a city located in the San Fernando Valley, in northwestern region of Los Angeles, California, United States. The population was 23,645 at the 2010 census, up from 23,564 at the 2000 census.-History:...
- City of San MarinoSan Marino, CaliforniaSan Marino is a small, affluent city in Los Angeles County, California. Incorporated in 1913, the City founders designed the community to be uniquely residential, with expansive properties surrounded by beautiful gardens, wide streets, and well maintained parkways...
- City of Santa AnaSanta Ana, CaliforniaSanta Ana is the county seat and second most populous city in Orange County, California, and with a population of 324,528 at the 2010 census, Santa Ana is the 57th-most populous city in the United States....
- City of Santa MonicaSanta Monica, CaliforniaSanta Monica is a beachfront city in western Los Angeles County, California, US. Situated on Santa Monica Bay, it is surrounded on three sides by the city of Los Angeles — Pacific Palisades on the northwest, Brentwood on the north, West Los Angeles on the northeast, Mar Vista on the east, and...
- City of TorranceTorrance, CaliforniaTorrance is a city incorporated in 1921 and located in the South Bay region of Los Angeles County, California, United States. Torrance has of shore-front beaches on the Pacific Ocean, quieter and less well-known by tourists than others on the Santa Monica Bay, such as those of neighboring...
- Calleguas Municipal Water District
- Central Basin Municipal Water District
- Eastern Municipal Water District
- Foothill Municipal Water District
- Inland Empire Utilities Agency (IEUA)
- Las Virgenes Municipal Water District
- Municipal Water District of Orange County
- San Diego County Water Authority
- Three Valleys Municipal Water District
- Upper San Gabriel Valley Municipal Water District
- West Basin Municipal Water District
- Western Municipal Water District of Riverside County
See also
- Water supply and sanitation in the United StatesWater supply and sanitation in the United StatesIssues that affect water supply and sanitation in the United States include water scarcity, pollution, a backlog of investment, concerns about the affordability of water for the poorest, and a rapidly retiring workforce...
- United States Environmental Protection AgencyUnited States Environmental Protection AgencyThe U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
- Colorado River AqueductColorado River AqueductThe Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...
- Los Angeles Department of Water and PowerLos Angeles Department of Water and PowerThe Los Angeles Department of Water and Power is the largest municipal utility in the United States, serving over four million residents. It was founded in 1902 to supply water and electricity to residents and businesses in Los Angeles and surrounding communities...