Snow Surveys

Second Snow Survey at Phillips Station, Jan 31, 2019

John King, Water Resource Engineer, of the DWR Snow Survey Section conducts the second snow survey of 2019 at Phillips Station in the Sierra Nevada Mountains with help from Science and Technology Policy Fellows Lizeth Perez, Sam Tucci, and Sydney Chamberlin of the California Council on Science and Technology.

Established in 1929 by the California Legislature, the California Cooperative Snow Surveys (CCSS) program is a partnership of more than 50 state, federal, and private agencies. The cooperating agencies not only share a pool of expert staff but share in funding the program, which collects, analyzes and disseminates snow data from more than 265 snow courses and 130 snow sensors located throughout the Sierra Nevada and Shasta-Trinity mountains.


California is the only western state to perform this function on its own. In the other western states, snow surveys are done by the federally funded Natural Resources Conservation Service, which began its program in the mid-1930s. Both programs are similar, and there is a high degree of cooperation between the two entities.


DWR is the lead agency in coordinating the CCSS program, which includes:

  • Maintaining snow surveying and sampling equipment
  • Training for our partner agencies 
  • Course measurement schedules and data collection
  • Fiscal and staff resource needs for the various partners within the program.

The CCSS program also forecasts seasonal and water year runoff for the major snow bearing watersheds in California. Water supply forecasts in the Bulletin 120 series are vital for planning and managing the state's water resource systems to benefit all Californians.


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