By Patricia Farris News Review Publisher– According to Jeremy Croft of the U.S. Army Corps of Engineers, as of Wednesday, March 29, Lake Isabella is approximately 353,000 acre-feet (AF). “We have over 200,000 acre-feet of capacity in the lake before the spillway would be used,” he said.
Last week the Army Corps of Engineers reported that they anticipated Lake Isabella would “fill and spill.” Its full would be 568,000 acre-feet.
The Kern River water has been rising rapidly due to the heavy rainfall of late. The heavy snowpack has also contributed to the possible threats hanging over people’s heads.
Lois Henry, CEO/Editor of San Joaquin Valley (SJV) Water, reported all expectations are that it will surpass the restricted level in short order, even though the restriction is still technically in place.
The lake started the week at well below 200,000 acre-feet but had risen to nearly 334,00- acre-feet by mid-morning Friday. Its total capacity is 568,000 acre-feet.
But the Army Corps of Engineers, which operates Isabella, hasn’t removed the 360,000 acre-foot restriction just yet.
According to Kern River Master Mark Mulkay, “The plan had been to fill the lake to 450,000 acre-feet and then ‘pause’ it there for about ten days so the Army Corps could test all its new equipment, see if it was getting more or less seepage than expected.”
With the amount of water coming into the lake now, and more expected as springtime temperatures melt accumulated snow, trying to “hold” the lake at 450,000-acre feet would be impossible. He said that outflow would have to be ramped up to between 10,000 and 12,000 cubic feet per second to keep the lake from overtopping.
“At those levels, water would wipe out Highway 178, cover the Kern River oilfields in two feet of water, flood parts of Bakersfield and run the river all the way up to the Tulare Lake,” Mulkay said. “We cannot do that.”
Instead, the plan is to ramp up the current outflow of 1,300 cubic feet per second (cfs) up to 5,000 cfs in the next few weeks.
“It will likely run that high through August, maybe well into September.”
And he said we could see a few weeks of water going over the newly constructed “labyrinth weir” spillway.
He tempered his predictions by explaining that many of these scenarios are based on models of what’s in the upper watershed because physical snow surveys haven’t been possible during all the recent extreme weather.
“Things are changing every day, and it’s just getting bigger and bigger and bigger,” Mulkay said.
Army Corps of Engineers link to Water Control Data System, showing hourly water levels in Lake Isabella: https://www.spk-wc.usace.army.mil/fcgi-bin/hourly.py?report=isb.
See the story on page four regarding work being done by the US Forest Service to reopen boating access to the lake.