The water content of the snowpack in the state is 81 percent of normal for this date, the California Department of Water Resources has reported.
The snowpack's water content was 80 percent of normal in March.
The fourth of five measurements during the winter season was taken last Thursday at the Phillips Station and other sites near Lake Tahoe, the DWR said.
The monthly measurements help water supply planners estimate the amount of spring snowmelt runoff into reservoirs.
Snow water content is important in determining the coming year's water supply and helps hydrologists prepare water supply forecasts, state officials said.
"A below-average snowpack at this time of year, especially following two consecutive dry years is a cause for concern," DWR Director Lester Snow said.
Manual surveys taken at four locations near Lake Tahoe and electronic readings indicate a snowpack water content of 87 percent in the Northern Sierra, 80 percent in the Central Sierra and 77 percent in the Southern Sierra, the DWR said. The readings last month were 84, 77 and 83 percent respectively.
Last year at this time the snowpack was 95 percent of normal, reflecting a drop of more than 20 percent from March 2008 caused by the driest spring on record, the DWR said.
The snowpack continued to melt early in 2008, resulting in a second consecutive critically dry water year, the DWR said.
Continuing dry conditions and regulatory restrictions on Delta water exports are limiting water deliveries to farms and urban areas. The DWR said it expects to be able to deliver only 20 percent of requested State Water Project water this year to the Bay Area, San Joaquin Valley, Central Coast and Southern California.