Geology and Ground Water in Indian Wells Valley, California

Abstract

1. Geology and water-bearing deposits.-Indian Wells Valley is virtually a closed basin bordered by consolidated generally non-water-bearing rocks. This basin is filled by unconsolidated deposits of clay, sand, and gravel derived from the mountains and bordering highlands. The principal waterbearing deposits are the younger and older alluviums; a main water body occurs in these deposits, principally beneath the surface extent of the younger alluvium. This estimate of transmissibility, utilized in conjunction with the crosssectional area and the hydraulic gradient of 1921, suggests an underflow at midvalley under natural conditions of about 15,000 acre-feet a year. The underflow is a measure of the recharge and discharge. The quantity of groundwater discharge estimated as the sum of evapotranspiration and groundwater outflow, or about 11,000 acre-feet per year under natural conditions, is about 4,000 acre-feet less than the estimate based on transmissibility, crosssectional area, and hydraulic gradient. 5. Perennial yield.-Perennial yield of a groundwater basin is the rate at which ground water can be withdrawn year after year without depleting groundwater storage to such an extent that withdrawal at this rate is no longer feasible because of increased pumping costs or deterioration of quality. The estimated perennial yield of Indian Wells Valley, based on estimates of evapotranspiration and underflow at midvalley together with other groundwater data, is approximately 12,000 acre-feet per year-about 4,000 acre-feet more than the estimated pumpage in 1953, but about 4,000 acre-feet less than the estimated total discharge.

Geologic and hydrologic features of Indian Wells Valley, California

“…In 1920 D. G. Thompson (1929) included the valley in a general investigation of the Mojave Desert Region. During the period 1925-55, Kunkel and Chase (1969) studied the geology and hydrology of the valley, collected a large quantity of data, and estimated the recharge, discharge, perennial yield, and storage in two large ground-water units in the central and western parts of the valley. By 1962 Moyle (1963) had compiled a reconnaissance geologic map of the valley and a report tabulating the hydrologic data collected by all workers and agencies prior to that time.…”

“…In the eastern part of the area where ground-wate^* is confined beneath clay or silt lenses, the coefficients of tranrmissivity and storage shown on plate 4 apply only to the deposits that contain the main water body of Kunkel and Chase (1969). The coefficients of transmissivity and storage are unknown for the deposits that contain the shallow water body of Kunkel and Chase (1969).…”

“…The coefficients of transmissivity and storage are unknown for the deposits that contain the shallow water body of Kunkel and Chase (1969). In the western part of the area, where the coefficients cf storage (pi.…”

“…The 1953 measurements by Kunkel and Chase (1969) afforded the most complete records for use in depicting the subsurface flow patterns for the entire basin (pi. 2).…”

“…Detailed field mapping of the principal ground-water discharge units and of depths to water in 1953, shown on plate 6, was completed by Kunkel and Chase (1969). The map data as well as the computations of evapotranspiration by Kunkel and Chsse (1969, figs.…”