Two vast underground water "reservoirs" known as the Central and West Basins, extending over 420 square miles, lie beneath the southeastern section of Los Angeles County. Nature has been storing water underground in the great basins for millions of years. Water produced from these basins has enabled people to transform a semi-arid region into one of the world's greatest population and industrial centers.
LBWD has the right to pump over 30,000 acre-feet per year of groundwater from the Central Basin. By the mid-1900's, this important supply of water to Long Beach was in serious decline from two major causes: with each passing year the amount of water flowing into the aquifer declined, while the amount of water extracted was increasing. Long Beach worked to address both of these problems.
Underground water in the Central Basin, from which groundwater is produced for Long Beach, has the San Gabriel Mountains via the San Gabriel River as its primary source. Increased water demand in the San Gabriel Valley significantly reduced the southerly flows to the Central Basin, which further contributed to the falling water tables. To protect this vital source of local water supply, in 1959, the Board of Water Commissioners instituted a lawsuit against major water producers in the upper San Gabriel Valley to guarantee water supplies to Central Basin producers. Parties to the lawsuit negotiated a settlement that provided the basis of stipulation for judgement (the "Long Beach Judgment") rendered by the Superior Court on October 8, 1965. This judgment guarantees the replenishment waters will flow forever.
In a separate action, Long Beach and other parties went once again to Superior Court to limit the amount of water extracted from the basin. In the early 1960's, the Superior Court issued a judgement prohibiting all extractions from the aquifer except by those parties listed in the judgement and limited extractions by those parties to specified amounts of water.
These two events were of major importance in securing local water supplies for the City of Long Beach, which depends on groundwater production for much of its needs.
Today, groundwater supplies provide the City of Long Beach with approximately 60 percent of its total drinking water demands. Not that long ago, the number was closer to 40 percent. Conservation has helped switch the City’s groundwater/imported water supply portfolio ratio from 40/60 to 60/40 in a very short time span. This is beneficial to ratepayers since the cost of groundwater is roughly half the cost of imported water.