Kern County makes river flood maps available to the public

May 17, 2023
by Lois Henry
Kern County Deputy Chief Billy Stiers explains how the county put together new flood maps, shown on the screen at a press conference Wednesday. Behind him are, left to right, Deputy Chief Zachary Wells, County Administrative Officer Ryan Alsop, Kern County Fire Chief Aaron Duncan and Kern County Sheriff Donny Youngblood. Lois Henry / SJV Water
Lois Henry

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The Kern River is rising fast and, so far, the public hasn’t been given very good information on the one question on everyone’s mind: Where’s it going to flood?

Wednesday, the Kern County Office of Emergency Services put out detailed, locally built maps that attempt to answer that question under various flow scenarios.

The upshot is there is no current emergency but people with property and animals in low lying areas from Hart Park to the Manor Street area should prepare as much as possible with sandbags and other measures and be ready to leave if necessary, according to responder agencies.

“We want to be very transparent and we want to provide information so the community can be prepared,” said Kern County Fire Chief Aaron Duncan during a press conference Wednesday where the maps were unveiled. “To do that, the information we provide has to be accurate and maps provided by FEMA and others were too broad brush.”

So, county staff hired a drone company to fly the river and matched that information with information from maps provided recently by the Department of Water Resources and Army Corps of Engineers. Then staffers walked the river corridor to “ground truth” measurements and put together maps now available on the county’s website.

“This is version one of these maps,” Duncan said. They will be updated as the weather and flow rates change.

Right now, the Army Corps of Engineers is releasing 7,225 cubic feet per second from Isabella Dam with the intention of ramping up to 7,500 cfs soon.

The new county maps show  areas with potential flooding in green, yellow and orange. Green denotes possible flooding at 7,500 cfs, yellow at 8,000 cfs and orange at 9,000 cfs.

New county map shows Manor Street in lower left. Green areas show anticipated flooding at 7,500 cubic feet per second, yellow at 8,000 cfs and orange at 9,000 cfs. KERN COUNTY

Every 1,000 cfs increase in river flows will mean a rise of a couple inches to two feet in water elevation, depending on the width of the river channel, officials said.

According to a May 8 outlook from DWR, river flows from the dam are expected to go above 9,000 cfs in mid-June, depending on the weather.

Responders stressed that the Army Corps’ goal is to keep flows at 7,500 even if water goes into the dam’s service spillway. That spillway is not to be confused with the “emergency spillway,” which is not expected will be used, according to an Army Corps announcement released May 9.

So far, there are no evacuation warnings or orders even for people living in areas of concern where the county has placed sandbag making machines and is working daily with residents in the Goodmanville Road, Manor Street and Choctaw Valley areas.

Highway 178 is still open and CalTrans is monitoring low spots, which still have one to two feet clearance from the river, said County Administrative Officer Ryan Alsop.

“These are all predictions based on the best available information at the time,”  he said. “These could change.”

He urged residents to sign up for alerts and information at

Sheriff Donny Youngblood summed up advice for those living near low spots along the river: “Have a plan.”



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