The cattle and horses were dying in early September 1864. Three years of little rain was burning through rangeland that had been unusually lush in 1861. Over-grazing now made the land barren. In Los Angeles County, 70 percent of the herds died or were slaughtered to leave forage for the rest. Carcasses were left where they fell. Out of reach beneath them - in some places, only a few dozen feet - pooled billions of gallons of life-sustaining water in the Los Angeles aquifer.New cycles of drought intensified the search for reliable water at the start of the 20th century. The worst dry period lasted for eleven years, from 1893 to 1904. In six of those years, rainfall was less 70 percent of normal; three consecutive years averaged less than 51 percent. The city of Los Angeles went looking for water in the foothills of the Sierras and found it in the Owens Valley. The communities west of the city and the towns on the Downey Plain punched some 3,500 wells into the Los Angeles aquifer for agriculture, industry, and the neat rectangular lots of suburban homes.
Artesian well in northern Long Beach at the turn of the 20th century. The aquifer paralleling the San Gabriel and Los Angeles rivers once produced more than a thousand artesian wells that flowed like this one. Photo courtesy of the Security Pacific National Bank Collection - Los Angeles Public Library.
The Los Angeles aquifer - collectively the water-bearing strata of gravel and silt that channel storm runoff and snowmelt - is immense and deep. The water in it is in almost constant motion from the foothills, through the San Fernando and San Gabriel valleys, under the plains west and south of downtown, and invisibly into the sea.
A chain of low hills formed by the Newport-Inglewood Fault, running from Culver City to Long Beach, splits the greater part of the Los Angeles aquifer into the West Coast Groundwater Basin and the Central Groundwater Basin. The largest portion is bounded by East Los Angeles to the north, Whittier to the east, Lakewood to the south, and the Florence-Firestone neighborhood to the west. (There are other Los Angeles basins with access to groundwater. Of particular importance to the city of Los Angeles is the Upper Los Angeles River Area Basin at Tujunga.)
Unlike water taken from streams and lakes, California had no set of basic laws regulating the extraction of groundwater. Consumers - particularly petroleum refiners beginning in the 1920s - could could take all the water they wanted. By 1953, groundwater extraction from the two basins reached a high of 331,600 acre-feet of water a year, almost twice the amount naturally recharging the aquifer from winter rains and spring snowmelt.
Well into the 20th century, the upper San Gabriel River took a meandering course through a knot of shallow beds. The underlying geology allowed the billions of gallons of rainwater and snowmelt flowing out of the San Gabriel Valley to sink into the aquifer under the Central Basin. Map of the San Gabriel Wash in 1900 courtesy of the US Geological Survey Historical Topographic Maps.
Overdrafting the basins was an accelerating catastrophe taking place unseen beneath the feet of unsuspecting suburban homeowners. Wells had to be drilled deeper and powerful electric pumps installed as water levels fell. (A well in Vernon fell an estimated 240 feet between 1904 and 1960.) Some wells went completely dry. And as the aquifer emptied from overdrafting, saltwater flowed in at the seaward edge of the West Coast Basin and began to threaten the larger Central Basin.
A partial solution to the crisis came in two parts. The aquifer beneath the two basins could be artificially recharged (something that had begun as early as 1890 when San Antonio Creek was diverted from its natural channel to spreading grounds at the mouth of San Antonio Canyon). And large landowners, public and private water companies, and industrial pumpers could establish an annual limit on the amount of water they took.
Recharging the aquifer under the West Coast and Central basins became the responsibility of the Water Replenishment District of Southern California (the WRD) when Los Angeles County voters set up the district in 1959. The WRD today is a regional government with a five-member board elected by voters, but the WRD's constituents are actually the pumpers who draw water from the two basins. The WRD closely monitors what the pumpers take out and what nature and an elaborate system of spreading grounds, reclamation plants, and water injection wells puts back in.
The pumpers pay for managing the system, as well as for the imported water the WRD buys to augment natural recharge of the aquifer. The pumpers pass the costs to their customers. The costs are higher in the West Coast Basin, where natural recharge is limited and saltwater intrusion must be slowed by injecting fresh water into the aquifer. The costs of pumping and imported water have gone up dramatically in the past decade.
The orange groves seen in this panoramic view of the San Gabriel Valley in 1930 were replaced by urban development by 1960, impacting the recharge of the aquifer under the Central Basin. Photo courtesy of the Security Pacific National Bank Collection - Los Angeles Public Library.
The Central Basin benefits from natural recharge. Storm runoff from the Rio Hondo and San Gabriel River, captured behind the Whittier Narrows Dam in South El Monte, is pumped over 1,000 acres of spreading grounds that flank Washington Boulevard. Wastewater, treated to near-drinkable quality, has augmented recharge from the spreading grounds since the early 1960s. At the south edge of the Central Basin, fresh water and treated wastewater are injected into barrier wells that hold the sea back.
The WRD accounts for how much water is put back in the aquifer. How much can be taken out each year was determined in a
