Water-resources data, 1970-75, for Perris Valley and vicinity, Riverside County, California

In 1969 the U.S. Geological Survey began in Perris Valley, Calif., to determine changes in the hydrologic regime as a rural area becomes urbanized. The investigations spanned several years when precipitation was below normal in most of southern California.

Surface-water records were collected for a 6-year period at 21 sites, and continuous precipitation records were obtained at four sites. Ground-water levels were tabulated from historical data at selected wells for 1941, 1968, and 1970. Water quality was monitored at several wells in the valley, and sediment data were collected at three surface-water gages. There was little increase in urbanization during the investigation.