Water & Drought

Is the drought over? No – but December snow survey is good news for California

Video: First Sierra snowpack measurement of season shows promise for easing California drought

The state Department of Water Resources conducted the season’s first manual measurement of the Sierra Nevada snowpack Wednesday, Dec. 30, 2015, and pronounced the results encouraging.
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The state Department of Water Resources conducted the season’s first manual measurement of the Sierra Nevada snowpack Wednesday, Dec. 30, 2015, and pronounced the results encouraging.

This time there was snow. A good deal of it, actually.

As California closed out its fourth year of drought, employees from the state Department of Water Resources conducted the season’s first manual measurement of the Sierra Nevada snowpack Wednesday. They pronounced the results encouraging.

Frank Gehrke, chief of the California cooperative snow surveys program, said the snowpack measured about 5 feet at Phillips, site of an old post office and stagecoach stop near Echo Summit. The water content totaled 16.3 inches, or 136 percent of average for Phillips for late December. The overall reading for the Sierra: 108 percent of average.

It was a heartening contrast with last April 1, when Gov. Jerry Brown accompanied Gerhke to the same spot and the two men stood somberly in a meadow completely barren of snow. Against that bleak backdrop, Brown announced an executive order requiring the state’s first-ever mandatory reductions in residential water use, restrictions that are expected to remain in place through next October.

The latest results gave Gehrke hope that California would make progress against the drought this winter, particularly amid forecasts of a strong El Niño season. But he said the true results will not be known until April or May, when the snowpack typically peaks.

“The critical thing is going to be for a real solid (snow) production in terms of the rest of the season and on into May,” he told reporters after the survey was concluded. “We’re encouraged, but we’ve got a good four to five months before the final tale is told.”

A pristine meadow at 6,820 feet of elevation just south of Highway 50, the Phillips station became a well-behaved media circus for about an hour Wednesday morning. Trailed by snowshoed media representatives from across Northern California, Gehrke and his crew plunged a hollow aluminum tube into the snow at six different points along a 200-yard stretch before calculating the snow depth and water content.

“This is clearly much better than it was last year at this time,” said Gehrke, who traversed the field on cross-country skis.

A second measurement, taken at nearby Lyons Creek, also showed encouraging results, with the snowpack at 120 percent of average.

Phillips and Lyons Creek are two of the 260 “snow courses” where officials will take periodic measurements between now and May. It’s a public-private effort, in which surveys are conducted by entities as diverse as Pacific Gas and Electric Co. and the Bass Lake Ranger District east of Merced. The manual measurements supplement nonstop electronic feeds, which rely on a series of flat steel “snow pillows” that sit on the ground and estimate snowpack based on weight.

As pleased as he was with the Phillips data, Gehrke cautioned that early snows can be deceiving. A year ago, the overall Sierra snowpack was at 50 percent of average for the end of December. By the time Gehrke and the governor arrived at Phillips in April, the overall figure was down to 5 percent. The results were so dismal that the state did not bother with the usual May 1 measurement.

“There’s hope, I think, so much more so than we had last year,” Gehrke said. “El Niño is not a slam dunk; it doesn’t guarantee you anything.”

Forecasters are largely convinced El Niño will bring heavy rains but they aren’t so sure about snow. While rain is important to California’s water delivery network, mountain snow is critical.

It provides 30 percent of the state’s fresh water in a typical year. Much of the spring snowmelt and mountain storm runoff is captured in reservoirs to be released later in the year to irrigate farms and supply cities far from the mountains.

While recent storms have raised the levels at many of the state’s reservoirs, they remain well below average. The state’s six largest reservoirs hold between 22 percent and 53 percent of their historical averages for this time of year. California’s largest, Lake Shasta, is holding around half of what’s average.

State hydrologist Maury Roos said the state’s 154 major reservoirs are holding a combined 11.9 million acre-feet, nearly 4 million acre-feet lower than last year. The total capacity for the reservoirs is 38 million acre-feet.

These low reservoirs are why state officials are offering only cautious optimism that this winter and spring will bring substantial drought relief. Still, Roos said it is not entirely unprecedented for one wet winter and spring to end a prolonged dry spell. He said it happened in 1978, after two years of severe drought, and again in 1993, after six years of drought.

“I’d say the chances are probably pretty good,” Roos said. “Obviously, we don’t want to count what we don’t have in the reservoirs.”

So what would need to happen for the state to declare the drought over?

“There’s no written-in-stone formula for that,” said Ted Thomas, a spokesman for the Department of Water Resources. “Hydrologically, we have guidelines we roughly go by.”

The state decides whether a drought has officially ended based on factors that would ensure California can weather the hot spring, summer and fall months, when little rain falls in much of the state.

Thomas said at least one of three things would need to happen for the drought to be over: statewide reservoir storage would need to be at 90 percent of average levels; runoff forecasts for the state’s water year, which runs from October to September, would need to be 110 percent of average; or reservoirs on the four major rivers in the Sacramento River basin would have to reach flood control stage.

“Any of those things gives us a pretty good signal that we can say, optimistically, that we’re nearing the end of the drought and perhaps have,” Thomas said.

Water districts that deliver drinking and irrigation water across the state said that while they were pleased with the mountain snow report, it does not alleviate the need to conserve water and prepare for future droughts.

“After four bone-dry years, we have a lot of catch-up to do, and it’s not likely to happen in one winter,” said Terry Erlewine, general manager of the State Water Contractors, California’s largest consortium of water agencies.

Amy Talbot, water efficiency program manager for the Regional Water Authority in the Sacramento area, said the snowpack does not alter the message she has giving to residents who receive water from the 22 districts her organization represents. On Wednesday, she renewed the call to shut off sprinklers, check for leaks and to replace indoor fixtures such as toilets with more efficient ones.

Brown’s executive order requires urban Californians to reduce consumption by an average of 25 percent, as compared with 2013. The order runs through February but has been tentatively extended through the end of October.

The short-term forecast bodes well for more snow.

Jim Mathews, forecaster with the National Weather Service in Sacramento, said the holiday weekend should be breezy, cold and clear, but next week should bring substantial rain to the Sacramento region and snow in the Sierra.

“We’re looking at rain and snow moving back into California. The first little wave comes through late Sunday into Monday,” he said. “There’s a little bit wetter system on the horizon for Tuesday and again on Wednesday. That system looks like it could give us three-quarters of an inch to maybe an inch of rain here in the Sacramento Valley and pretty good snow – maybe a foot or more – in the Sierra.”

Dale Kasler: 916-321-1066, @dakasler