A final snow survey for the season came up empty at Phillips Station, with no snow to measure. According to the Department of Water Resources (DWR), the water content in California’s snowpack is only 17 percent of normal, meaning below average water supply this summer.
Results of manual surveys at other sites by DWR off Highway 50 near Echo Summit showed at most 3.3 inches of water content.
Because of the record dry January and February in much of the state, DWR is projecting is will only be able to deliver 35 percent of requested water from the State Water Project. Twenty-nine different agencies purchase state water and supply it to more than 25 million Californians and nearly a million acres of irrigated agriculture throughout the state.
DWR noted that a reduction in water delivery is not only due to a light snowpack and reduced rainfall, but because of pumping restrictions needed to protect the Delta smelt and salmon.
DWR said storms in November and December built California’s snowpack water content to 134 percent of normal by January when the first snow survey was conducted. But manual surveys and electronic readings have recorded a decline in the water content since drier weather set in. Statewide the second manual survey found the snowpack water content at 93 percent; in February it declined to 66 percent of average; and in March, it was 52 percent of normal.
According to a press release, “Electronic readings indicate that water content in the northern mountains is 16 percent of normal for the date, and 11 percent of the April 1 seasonal average. Electronic readings for the Central Sierra show 23 percent of normal water content for the date and 18 percent of the April 1 average. The numbers for the Southern Sierra are 9 percent of average for the date and 7 percent of the April 1, full-season average.”
DWR is now doing aerial surveys of the snowpack in addition to manual and electronic surveys. The Airborne Snow Observatory Program is a pilot project between DWR and NASA’s Jet Propulsion Laboratory Airborne Snow Observatory. The aerial surveys utilize Lidar technology to measure the snowpack’s depth and reflectivity.
“This additional information, when combined with data from the traditional manual snow surveys and electronic sensors, can provide a better estimate of California’s water supply,” according to DWR.
Despite the reduced snowpack, the key reservoirs in the state are at near normal levels for the date, with the San Luis Reservoir being the exception. Lake Oroville, the State Water Project’s principal storage reservoir, is at 103 percent of its average level for the date. Shasta Lake, the federal Central Valley Project’s largest reservoir, is at 95 percent of its normal storage level for the date. Reservoir storage is expected to meet most of this year’s water demand, but successive dry years would create drought conditions in some areas.
Contact Dawn Hodson at 530-344-5071 or firstname.lastname@example.org. Follow @DHodsonMtDemo on Twitter.