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By Mark Grossi
The Fresno Bee - June 16, 1998
California's delayed spring thaw seems to be a kinder and gentler aftermath
to the El Nino winter. So far.
El Nino's winter storms caused $500 million in flooding damage and left a snow pack about twice its normal size. Now, with warmer weather arriving weeks late and a thick snow pack still waiting, a stretch of 100-degree days could pump up those damage totals.
The San Joaquin River tributary system alone - including the Merced, Stanislaus and Tuolumne rivers - will send more than 1 million acre-feet of snow melt to the San Francisco Bay over the next five weeks, federal officials say. That's enough water to supply Fresno for about the next seven years.
With that much water, everything depends on how fast or slow the snow melts.
"The snow pack is primed now," Doug Woodman, Kings River watermaster, said Monday. "If it gets real hot for a week or more, it will come down faster. But that's not happening right now. We're having a slow melt."
The National Weather Service indicates the weather will cooperate, with San Joaquin Valley readings in the low 90s today and Wednesday. Still, the overnight temperature Sunday at 10,200 feet above the Kings River was 39 degrees, meaning the high Sierra did not freeze during the evening.
Campers noticed the higher temperatures and snow melt in Yosemite National Park along the Merced River. The rising Merced flooded 30 camp sites Monday, forcing outdoor enthusiasts to other sites.
Park officials expected the river to rise again overnight, but they said the flooding was a common late spring event. They said it was nothing like the crippling January 1997 flood, which filled Yosemite Valley.
"The river peaked at 9.4 feet at 2 a.m. Monday," said Yosemite spokesman Kendell Thompson. "But, for the most part, the river is still in its banks."
In the Valley, the Kings River was flowing at capacity and continued to spill over its banks in the Reedley area, flooding at least two campgrounds.
Most other Central California rivers were within their banks, said the U.S. Army Corps of Engineers, which is responsible for controlling floods.
The Corps daily tracks the amount of river water running into and out of reservoirs, said spokesman Jason Fanselau. The agency must make sure there is enough room in reservoirs to catch the snow melt and protect downstream property.
Dam operators must balance the inflow and the outflow to maintain enough room.
The San Joaquin, for instance, is running into Millerton Lake, northeast of Fresno, at about 27,000 acre-feet per day. Each acre-foot, about 326,000 gallons, brings Millerton a little closer to its 520,000 acre-foot capacity. The lake level stood Monday at about 411,000 acre-feet, or about 80% full.
To slow the rising water, the bureau is releasing 15,000 acre-feet each day down the river channel. Farmers are taking 3,000 acre-feet more daily for irrigation.
Aside from protecting downstream property, the balancing allows officials to slowly fill the reservoir for farm irrigation throughout the summer.
"We're managing the water," said Tony Buelna, chief of Friant Dam operations at Millerton. "The reservoir should be full sometime between July 5 and July 15, if we don't have some extremely high temperatures."
Normally, Millerton would fill by June 15. But April and May were unseasonably cool, most of the snow didn't melt, said hydrologist Pierre Stephens of the state Department of Water Resources.
"More than two-thirds of California's runoff occurs between April and July," he said. "But this year, a lot of it is coming after June 1. And this is probably going to be among the 10 highest runoff years in this century."
He predicted the San Joaquin would send down 2.2 million acre-feet of snow melt from the Sierra between April and July. The river has averaged almost 1.3 million acre-feet during those four months over the last 50 years.
Smaller streams, such as the Tule River in Tulare County, are also having unusual years up and down the 400-mile Sierra range. Stephens said the Tule will flow with more than three times its normal amount.
"I think August and September flows will also be appreciably higher than normal," Stephens said. "Usually, many rivers dwindle a lot in late summer, but we should see at least some flows continue this year."
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