Northern California is on track to break rainfall records. Water has gushed through a weir into the Yolo Bypass floodplain at levels not seen in more than a decade. The Sierra Nevada snowpack is nearly double historical averages.
But you wouldn’t know the region has experienced an exceptionally wet winter looking at the steep, dry shores ringing the Sacramento region’s largest reservoir, Folsom Lake. On Wednesday, the lake was filled to just 41 percent capacity – 80 percent of its historical average.
Folsom Dam operators say the low levels are necessary to protect Sacramento from flooding. With runoff from recent storms subsiding and forecasts of sunny skies through early next week, dam operators are gradually dialing back releases into the lower American River. That should allow the lake to rise again.
That’s small comfort for some local residents, such as Steve Clark, who grew tired of seeing their lake drained practically dry during California’s historic five-year drought.
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Clark said he’s frustrated that the lake’s been reduced to an “ugly brown puddle,” and he’s worried that even with bountiful rain the lake won’t be allowed to fill this spring. He argues that draining Folsom Lake is bad for local property values, limits summer recreation and harms the region’s water supply.
“We don’t want to see Sacramento flood, either, but are they going overboard with those concerns?” said Clark, an engineer who lives is El Dorado Hills.
Louis Moore, a spokesman for the U.S. Bureau of Reclamation, which manages Folsom Dam, said he understands such complaints, but dam managers are required to keep space in the lake as a buffer to protect Sacramento from flooding.
Folsom is a relatively small lake – less than a quarter of the size of Shasta Lake, the state’s largest reservoir – yet it can receive huge amounts of water in very short periods from the massive mountain and foothill watershed that feeds into it.
Moore said it’s better to keep the lake lower this time of year in case it needs to capture a rush of storm water. The alternative, he said, is to wait for a major storm and then make unsafe “knee-jerk” releases into the American River, which runs through Sacramento contained only by levees.
“We’re at the time of year that the storms can come up, and they can be pretty hard-hitting,” Moore said. “Folsom can fill two to three times in a wet year.”
He said the good news is that with so much snow in the mountains, prospects are good for a fuller Folsom Lake this summer and fall.
A solid snowpack can store millions of acre-feet of water through the spring and early summer, refilling the reservoirs and effectively extending the “rainy” season.