Water-resources data for the 1974 water year for California include records of data for the chemical, physical, and biological characteristics of surface and ground water. These data were collected from designated sampling sites at predetermined intervals such as once daily, weekly, monthly, or less frequently, and at some sites data were recorded on punched paper tape at 15-, 30-, or 6O-minute intervals. The distribution, type, and number of stations in each river or drainage basin are shown in figure 1. A few pertinent stations in bordering States are also included. The records were compiled by the Water Resources Division of the U.S. Geological Survey under the direction of Lee R. Peterson, district chief. These data represent that part of the National Water Data System collected by the Geological Survey and cooperating State and Federal agencies in California.The Geological Survey has published records of chemical quality, water temperatures, and sediment since 1941 in an annual series of water-supply papers entitled, "Quality of Surface Waters of the United States." Beginning with the 1964 water year, water-quality records have been released by the Geological Survey in annual reports on a State-boundary basis. These reports are for limited distribution and are designed primarily for rapid release of data shortly after the end of the water year. These records will be published later in Geological Survey water-supply papers.
