 The two Crystal Springs lakes and San Andreas Lake used to be known as "Spring Valley Lakes" for the Spring Valley Water Company which owned them.Lower Crystal Springs Reservoir now covers the town of "Crystal Springs" which grew up around a resort of the same name.From the Crystal Springs Dam San Mateo Creek flows generally northeast 8 km (5 mi) through San Mateo where it is partly intermittent and altered, to San Francisco Bay about 1.1 km (0.7 mi) west of the mouth of Seal Slough.