P.R. Wood 1975 San Mateo County has several densely populated urban areas that get most of their water supplies from surface-water sources that could by damaged by a major earthquake or other general disaster. In the event of such a disaster, limited supplies of potable water may be obtained from selected wells, springs, and perennial streams. This report outlines the principal sources of existing water supplies, gives information on the need for emergency water-supply procedures, presents general criteria needed for selecting emergency water-supply wells, summarizes information for 60 selected water wells, numerous springs, and perennial streams that can be used as sources of water, and describes emergency water-purification procedures that can be used by individuals or small groups of people. application/pdf 10.3133/ofr7543 en U.S. Dept. of the Interior, Geological Survey, Sources of emergency water supplies in San Mateo County, California reports