Sierra snowpack expected to be smallest on record

Most of California’s summer water supply arrived this winter in just a few warm Northern California rainstorms — a bleak setup for crushing news that the vital supply from the Sierra snowpack will be the smallest in more than a century.

State water leaders Thursday told water district leaders, farmers, bankers and many others at California State University, Fresno, to expect possibly a record-breaking small snowpack. The snowpack usually supplies about one-third of the state’s water, and it is 12 percent of average right now.

“At this point in the year, we won’t get storms that will build a snowpack,” said Jeanine Jones, the state’s deputy drought manager and interstate resources manager. “What you see is what we will have.”

The briefing, sponsored by the state Department of Water Resources and the Water Education Foundation, is an attempt to explain the dire situation after four years of drought. A similar briefing is set for April 9 in Sacramento.

In Fresno on Thursday, officials explained California’s water systems in historical depth, emphasizing the way the state is plumbed and the uses for water — including cities, farms and nature.

The Sierra snowpack discussion stood out as the worst news.

A cascade of reactions and possible calamities is set in motion by the tiny snowpack — more groundwater pumping, loss of private wells in rural areas, severe city water restrictions, fallowed farmland and the threat of catastrophic wildfires in forests.

“We didn’t have a big wildfire last year, but remember the Yosemite-area Rim fire a couple ofyears ago,” Jones said. “There’s a potential for very damaging wildfires after four years of drought.”

Projections for April-through-July snowmelt runoff are 20 percent of average on some rivers, such as the San Joaquin.

The projected low runoff into the Sacramento Valley could very well set a record, said John Leahigh, chief of water operations in the state water resources agency.

“Because the storms this winter were warm and mostly rain events, we’ve already seen much of the runoff in that area,” he said. “The San Joaquin Valley is even worse because the big December rain didn’t really happen there.”

Officials pointed to a San Joaquin precipitation index that could wind up with the lowest total ever recorded in the area, which includes totals from five Sierra locations. The locations are at the Calaveras Big Trees, Hetch Hetchy, Yosemite headquarters, North Fork and Huntington Lake.

Last year at those locations, February and March storms boosted the 2013-14 winter beyond the driest years on record. But February was not a big month this year, and March has been very dry, officials said.

San Joaquin Valley farmers can’t count on much water from the San Joaquin, Kings or most other rivers in the region. Valley farmers who buy Northern California river water from the federal Central Valley Project have been told to expect zero allocations.

Compounding the problem, federal export pumps in the south Sacramento-San Joaquin River Delta have been slowed to avoid clogging them with an invasive hyacinth plant.

The State Water Project is forecasting 20 percent deliveries. The state’s water pumps are in a different location than the federal pumps and have not been plagued by hyacinth, which has allowed them to send more water south into San Luis Reservoir in Merced County.

This story was originally published March 19, 2015 at 10:13 PM with the headline "Sierra snowpack expected to be smallest on record."