Gin Flat, by Yosemite, is the place to measure.
California's water fortune is told at Gin Flat
Sierra Nevada outpost is where the convergence of snow, sun and temperature enables scientists to predict floods or drought. A lab at 7,000 feet measures the snowpack, a main source of state's supply.
By Deborah Schoch
Los Angeles Times Staff Writer
March 3, 2008
GIN FLAT, CALIF. -- — In deep winter, water scientist Frank Gehrke straps on his cross-country skis and trudges uphill in the thin, cold air to one of the most closely monitored frozen meadows on the continent, 7,200 feet above sea level in the Sierra Nevada.
To understand why his arduous, breath-sucking hike is important, stand still and listen to the snow. In the pale morning sun, the forest of pine and cedar comes alive with sound. Clumps of fresh powder fall with a thud or drip-drop from tree tops, quickening with the staccato of popping corn.
This place is like a Rosetta Stone for California's water supply. It's where the convergence of snow, sun and temperature enables scientists to predict floods or drought. It's where they have installed sophisticated equipment to help understand how climate change is altering snow melt in the Sierra, a source of water for millions of Californians.
"Gin Flat's always been the place where we try things and invest first," said Michael D. Dettinger, a U.S. Geological Survey hydrologist based at Scripps Institution of Oceanography in La Jolla.
Although the state oversees more than 300 survey sites, what makes Gin Flat unique is its location, an elevation in Yosemite National Park just above the point where rain commonly turns to snow. That makes it an ideal spot to test the premise that a warming climate will produce more rain at higher elevations -- a shift that would bring more flooding and less snowpack to fill California reservoirs in mid-summer.
These days, with water woes plaguing the state, readings at Gin Flat will ultimately help determine how much more it could cost Californians to drink a glass of water or take a shower, or if they can water lawns without restrictions.
That is why Gehrke, 60, didn't hesitate to ski three miles up the mountain last week, hauling a sled loaded with 60 pounds of fuel cells and tools. He is California's snow survey chief, a man respected as the don of the Sierra snowpack. As caretaker of Gin Flat, he needed more power to fuel all the equipment at the site he helped develop.
Last week, his agency, the state Department of Water Resources, reported that Sierra snowpack was at 118% of normal for this date, compared with 63% of normal at this time last year, the driest year on record for Los Angeles.
But Gehrke is a cautious man, and never more so than when explaining snowpack surveys.
"We could slide back to below average. A March without snow could do it," he said. "A lot of the reservoirs are pretty low from last year."
That would be bad news for Southern California, which depends heavily on imported water, about half from northern mountains and the rest from the drought-stressed Colorado River. Further straining supplies, a court decision protecting a rare fish in the Sacramento-San Joaquin River Delta has reduced deliveries to the south by 30%. To comply with court stipulations, state officials last week cut southward flow for seven days by 75% of normal.
… Gehrke and other scientists have equipped 11 sites in Yosemite with high-tech monitors, turning one of America's most famous parks into an electronic snow laboratory.
Gin Flat, east of the park's Big Oat Flat entrance, is named for a long-gone speak-easy. It provides a snowpack record dating back to 1930 that makes today's data even more valuable.
In this outpost, devices measure the weight and temperature of snow, the strength of the sun rays heating the snow and the moisture in soil under the snow. Sonar-like sensors test the depth of the snow. Results from Gin Flat are reported hourly and transmitted every three hours to Virginia and then back to Sacramento.
