The Los Angeles River in the San Fernando Valley, 2000
Photograph by author
PAST, PRESENT, AND POSSIBILITIES
WATER SUPPLY
Given Los Angeles' reputation for water imperialism and its fame as a city built by aqueducts, it is astonishing to learn that 1/3 of the region's population receives its drinking water from wells, pumping the vast aquifers under the valleys and coastal plain. These underground reservoirs represent centuries of rain runoff from the mountains, as winter storm water soaked into the ground when floods spread across the sandy soils of the lowland areas. But with the onset of urbanization in the twentieth century, this pattern was altered, forcing flood waters into concrete storm drains, destined for the ocean. A growing population has not only increased water demand, but also increased the outflow of the Los Angeles River during storm events. Combined with the use of the river as an outflow for treated waste water, this situation has in fact tripled the river's natural surface flow. Although various programs and spreading basins exist to capture this water for aquifer recharging, enough water to supply the annual needs of 1 million people still escapes into the ocean.
Population and water use data for river basins of each state is available from the United States Geological Survey
The Los Angeles County Department of Public Works provides information on the 15 dams, 115 debris basins, and 32 groundwater recharge reservoirs it maintains, in addition to other hydrological data.
Information about groundwater usage and efforts to supplement underground reservoirs with treated waste water, aqueduct water, and recycled storm water through aquifer recharge basins operated in conjunction with the County Department of Public Works is available through the Water Replenishment District of Southern California.
The mouth of the Los Angeles River at Long Beach, 2000
Photograph by author