NORTHERN REGION OFFICE
Early Water Use
Early settlers coming into the areas overlying the West Coast and Central Basins found a sufficient supply of surface water for their needs. But by 1870, when the artesian wells and springs lying east of the Newport-Inglewood fault zone had stopped flowing, water users were forced to drill shallow wells. These supplied enough water for development and economic growth in the Coastal Plain to continue.
Development of groundwater advanced dramatically in 1909 with the introduction of the deep-well turbine pump. Its tremendous adaptability and superior operating characteristics placed efficient water wells within economic reach of almost everyone. Dependable sources of water attracted industry and agriculture, and in time, the demand for water exceeded the natural replenishment of the basins. By 1920, water levels throughout the West Coast Basin had dropped below sea level and wells along the ocean were being abandoned because the water was too salty. Within 12 years, the entire coastal reach of the West Coast Basin had been invaded by sea water.
Water Associations Formation
Groundwater quality continued to deteriorate so that in 1945, the California Water Service Company, City of Torrance, and Palos Verdes Water Company filed suit in Superior Court of Los Angeles County to quiet title to the groundwater rights of each pumper in the West Coast Basin and to establish control over groundwater extractions from the basin. A year later, the West Basin Association was formed. A plan to manage the water resources in the basin was set up to: (1) provide a supplemental water supply for major producers, (2) limit groundwater extractions, and (3) create an exchange pool to provide pumping rights for those users who lacked access to supplemental supplies.
In the Central Basin, the deteriorating groundwater situation in that basin led to formation of the Central Basin Water Association in 1950, with goals similar to those of the West Basin Association.
Natural replenishment of the Central Basin is largely from surface inflow and some underflow from the San Gabriel Valley through Whittier Narrows. West Coast Basin, in turn, receives underflow from the Central Basin. Also adding to the supply coming into the Central Basin and later into the West Coast Basin is water spread onto areas within the Central Basin where the water can percolate to the underground aquifers. Another method used to replenish the basins is in-lieu replenishment whereby a producer with access to a supplemental supply can use that water instead of water pumped from the basin.
To provide a supplemental supply for the basins, the West Basin Municipal Water District, which was formed in 1947, and the Central Basin Municipal Water District, formed in 1952, were annexed to the Metropolitan Water District of Southern California through which they could obtain water from the Colorado River. Later, when water from the State Water Project became available, it was also brought into the water districts.
The two water associations were instrumental in formation of the Central and West Basin Water Replenishment District (now Water Replenishment District of Southern California) to replenish and maintain the groundwater basins by purchasing imported water, recharging the basins, and halting sea water intrusion.
To limit groundwater extractions and create an exchange pool for producers without access to supplemental water, the two water associations sought relief through the courts. The West Basin Water Association began legal action in 1946 and the Central Basin Water Association in 1962
In response to the court's request to the Department of Water Resources to define the boundaries of the West Coast Basin and to determine its geohydrologic characteristics, the Department spent six years analyzing the physical properties of the basin. The major water producers retained an Engineering Advisory Committee to aid in the investigation.
In 1955, the court approved an Interim Agreement drafted by the water users in the West Coast Basin and appointed the Department as Watermaster to administer it. In 1961, the court rescinded the Interim Agreement and signed the West Coast Basin Judgment, retaining the Department as Watermaster. The judgment has been amended four times since then.
The final judgment in the Central Basin case was signed in 1965 and became effective a year later. The Department was appointed Watermaster for this basin also. The judgment has been amended twice.
Every groundwater pumper reports its extractions each month to the Watermaster, who computes the amount pumped thus far in the current fiscal year and the amount that can legally be pumped during the remainder of the fiscal year. An updated copy of its account is provided to each pumper every month. At the end of the year, the Watermaster prepares an annual report for the court and for each party to the judgment.
To ensure that meter readings are accurate, the Watermaster field staff tests the accuracy of the water meter on every active well at least once every two years. Follow-up tests on repaired meters and initial tests on new meters are scheduled whenever necessary.
To halt sea water intrusion into the basins where they are exposed to the ocean, the Los Angeles County Department of Public Works has created three barrier projects to inject surface water. The injected water creates a pressure ridge that impedes the inland movement of the salt water front and maintains protective groundwater elevations in the aquifers.
The barrier projects protecting the West Coast Basin are the West Coast Project, which consists of a line of injection wells that parallels the coastline from Los Angeles International Airport to the Palos Verdes Hills, and the Dominguez Gap Project along the San Pedro Bay. The water injected in the West Coast Barrier is recycled water from the West Basin Reclamation Plant in the City of El Segundo, which is owned and operated by the West Basin Municipal Water District. The plant gives tertiary treatment to water from the Hyperion Wastewater Treatment Plant.
Treated water from the West Coast Basin Reclamation Plant is also distributed for industrial and landscaping purposes to free an equal amount of fresh water for domestic use.
The Central Basin is protected by the Alamitos Barrier Project at the mouth of the San Gabriel River (Alamitos Gap). The barrier consists of a saline water extraction trough and a fresh water injection pressure ridge. The project includes a number of observation wells to monitor groundwater levels and water quality.
In addition to the reclamation plant, the West Basin Municipal Water District has also constructed a 1.5-million-gallon per day desalter in the City of Torrance as a pilot plant to treat brackish groundwater. The plant is designed not only to demonstrate desalting technology, but also to improve groundwater quality and management.
In fulfillment of the third request of the water associations, the judgments provide for establishment of an exchange pool in each basin to make additional water rights available to parties without a supplemental supply. To use the pool, each pumper, at the beginning of the year, estimates its demand and supply for the year. Those pumpers whose total supply is less than their estimated demand are able to obtain, through the exchange pool, water rights from pumpers that have foreseen a surplus.
Both judgments also contain provisions for transfer of water rights ("adjudicated
rights" in the West Coast Basin and "allowed pumping allocations"
in the Central Basin) by lease or sale. Records of these transactions are
maintained by the Watermaster.