A prolonged warm spell this spring is weighing on Kern River Watermaster Mark Mulkay’s mind these days.
“If that happens, we could lose infrastructure. Definitely,” he said.
A new Department of Water Resources estimate of accumulated snow hanging above the state’s river systems shows the Kern River’s watershed at 422% of normal. The amount could be slightly higher or lower, but still record breaking.
He said that means there could be as much as 1.8 million acre feet that will come through Isabella Lake between April and July. The lake holds 568,000 acre feet so water managers need to find a home for 1.2 million acre feet.
“And we have another storm coming,” Mulkay said, shaking his head in disbelief.
There’s no doubt Lake Isabella will fill to its newly re-established maximum capacity and that water will go over the spillway, Mulkay said.
The question is whether several warm days in April or May will speed the inflow and could force so much water to be jettisoned from the dam that it could flood or wash out Highway 178, overwhelm bridges in Bakersfield and even send water over the central and northern parts of the city.
Mulkay said the river channel in the Kern River canyon can take as much as 5,400 cubic feet per second if the water is managed carefully but even at that amount Highway 178 could flood in spots. If warm weather ramps up the snow melt, though, he said there could be times this June and July when water in the channel hits 9,000 cfs.
At that amount, the river would make the highway impassable, cutting off residents in the Kern River Valley and threatening bridges in the valley. Flows could be actually higher in the valley as streams and runoff below Isabella Dam will continue adding to the flow through Bakersfield.
“(City of Bakersfield) Crews are out right now fortifying bridges and installing siphons over the Coffee Road weir to move water over that point so it doesn’t create a pinch point,” Mulkay said.
The Army Corps of Engineers, which owns and operates Isabella, is moving as much water as it can out of the lake now to “dig a hole” in Isabella to make room for the coming snow melt.
Outflow was increased to 4,250 cfs recently and inflow has dropped to 3,100 cfs after a blast of water from a warm, drenching storm on March 10 pushed inflow up to more than 40,000 cfs and devastated ares of Kernville.
The lake is currently holding about 346,000 acre feet.
So, things are steady for now with cooler temperatures. But all eyes are on the coming spring.