The Saugus-Newhall area is in the upper Santa Clara River valley, in northwestern Los Angeles. County, about 30 miles north of Los Angeles. The area has two main aquifers, the alluvial aquifer and the underlying Saugus aquifer. These two aquifers are the subject of this investigation. The alluvial aquifer consists of river channel alluvium as much as 200 feet thick with a transmissibility ranging from 50,000 to 325,000 gallons per day per foot and a storage coefficient of i0 to 20 percent. In 1945 about 210,000 acre-feet of recoverable ground water was in storage in the alluvial aquifer. The alluvial aquifer is the major source of ground-water pumpage and has supplied about 600,000 acre-feet of effective pumpage during the period 1945 through 1967. Ground-water pumpage and variations in the quantities of surface-water recharge have caused large fluctuations in the water levels in the alluvial aquifer. The Saugus aquifer has. a...