Underconstruction

CHINO BASIN WATER CONSERVATION DISTRICT

CHINO GROUND WATER BASIN (AQUIFER)

Within many of the displays located in and about the Demonstration Garden are references to “ground water” and the “Chino Ground Water Basin.” Contrary to images of huge underground lakes and rivers, ground water is the water that accumulates in the tiny spaces between the alluvial material (sand, gravel, silt, and clay), or in the crevices in fractured hard rock. These water-bearing geologic formations are known as “aquifers.”

Aquifers can extend for hundreds of miles and store immense amounts of water; they may be just a few feet or hundreds of feet deep, and they may be located immediately below the earth’s surface or deep underground. The drawing below not only depicts what a typical aquifer might look like, if a slice was taken through the earth’s crust, but also is representative of the interaction between typical Supply and Demand activities (Supply consisting of precipitation, runoff, imported water, and upstream deep percolation and Demand being made of crop transpiration, evaporation, runoff, underflow, and export/ground water pumping.).

Very much like the drawing below, the Chino Ground Water Basin is an area generally bounded by the Jurupa Mountains on the East, Santa Ana River on the South-east, Chino Hills on the South-west, San Jose Fault line to the West, and the Red Hill and Rialto-Colton Fault lines to the North. Recent studies indicate that the Chino Ground Water Basin held approximately 5,200,000 acre-feet of water in 1961 and gradually declined in storage to about 4,550,000 acre-feet in 1989. Due to the water conservation efforts of public agencies such as the Chino Basin Water Conservation District, and the willingness of all Chino Basin water users to become actively involved in various water conservation programs, the steady decline in stored water volume has ceased with the present storage at or near the 1989 storage volume.