California snowpack at decade high, reservoirs still down. What about the drought?

Drained after years of drought, California’s water supply is being bolstered this winter by an early abundance of snow. If only the state’s largest reservoirs can catch up.

Amid a brief pause in the onslaught of winter storms slamming the state, water officials trudged through fresh snow at Echo Summit south of Lake Tahoe on Tuesday to confirm what more than a hundred sensors across the Sierra already show: The California Sierra snowpack is at the highest point in a decade for this time of year.

“Our snowpack is off to one of its best starts in the past 40 years,” said Sean de Guzman, manager of the California Department of Water Resources’ monthly snow surveys, at a news conference on Echo Summit.

And the bounty will continue to grow as several feet of snow is expected to hit parts of the mountain range in the coming days. It’s a welcome start to winter as California struggles through a third year of drought — the Golden State relies on melting snow each spring for about a third of its water supply.

On Tuesday across the Sierra, California’s snowpack was at a staggering 174% of normal for this time of year. At Echo Summit, Tuesday’s in-person snowpack measurement — which these days is more ceremonial than scientific necessity — came in a shade higher, at 177% of average. But sky-high early snowpack readings do not guarantee that the Golden State will escape its lingering drought. Last year and in 2013, above average snowpack at the start of the New Year diminished when the precipitation abruptly stopped in ensuing months. In both years California’s snowpack ended in a significant deficit, prolonging drought conditions.

And although those gathering on the 7,000 foot-high summit were elated about the impressive snow haul, reservoirs at lower elevations tell a different story. Many of California’s biggest reservoirs that store the state’s precious water are significantly below average for this time of year, despite last week’s storm.

A Bay Area News Group analysis of the state’s biggest reservoirs found that water storage levels Monday were 27% lower than the 20-year average for that date. That analysis includes 11 years of drought.

The deficit is being fueled by water shortages at some of Northern California’s biggest reservoirs. The Shasta Reservoir is at 34% total capacity, which is just 57% of the historical average. The Oroville Reservoir is faring slightly better, at 38% of total capacity, still only 72% of the historical average. However, the Folsom reservoir is 61% of capacity, which is 148% of the historical average for this date, while farther south, Don Pedro is also at 61% capacity, and 90% of its historic average.

“Frankly, I’m more interested in the precipitation than the snowpack because the reservoirs are so empty down below,” said Jay Lund, professor of Civil and Environmental Engineering at UC Davis. “Last year at this time, we’d had more precipitation.”