The influence of ground water storage on the runoff in Southern California

Ground water seepage from underground water aquifers into streams has been the principal agricultural supply for many years in southern California coastal plain areas. Physiographic and climatological features of this important section of California are described. Runoff distribution of streams is depicted graphically. Ground water seepage is separated from the hydrograph of flash storms from rainfall. These methods are substantiated by experimental work done in the San Gabriel Mountains by the U.S. Forest Service at the San Dimas Experimental Forest. The subsurface water storage is estimated to produce 80 to 90 percent of the annual flow in many of the streams.