sentences:  The increase in water flow in San Juan Creek allowed it to maintain its course as an antecedent stream, rather than being diverted to the east or west.The U.S. Geological Survey (USGS) measured the discharge of San Juan Creek in the city of San Juan Capistrano for two periods, from 1928–1969 and from 1969–1985.Stream flows for the earlier period are considerably different from the later period due to increased volumes of urban runoff.