Historic rainfall causes local reservoirs to fill fast, triggering flood releases
-January 13,2023-
Reservoirs from Friant near Fresno south to Lake Isabella all got a huge pulse of runoff in the past few days transforming mostly empty foothill lakes into potential drought busters.
Water managers monitoring both the Kaweah and Kings River watersheds are pumped up over the volume of precip falling in the past few days in the Sierra. While many communities across the state are focusing understandably on flood damage from the parade of atmospheric river storms that have targeted California, it’s the potential relief from 3 years of drought resulting in a huge hardship for the local economy here that have gotten the attention of Mark Larsen on the Kaweah and Steve Haugen who oversees the Kings River.
“We’re pretty excited” says Larsen, who is GM at the Kaweah Delta Water Conservation District. “Instead of fighting over water we don’t have, we are able to focus on managing a good volume of water we do have.”
Literally overnight, both watersheds stretching north from Tulare to Fresno counties saw 8 to 10 inches of rain and then snow hit January 9/10 at measuring stations including Giant Forest in the upper Kaweah and Wishon /Courtright reservoirs on the upper Kings. Wishon has received 38 inches of precip as of January 10, up 8.5 inches from the day before.The dam had just 5 inches in the bucket December 1 – gaining 33 inches of precip since.
The relatively warm storm dropped rain as high as 8500ft, Haugen says, sending runoff into Pine Flat Dam.Haugen is watermaster for the Kings River Water Assn. Pine Flat itself received nearly 4 inches of rain on January 9.(Pictured Pine Flat Dam)
The same storms appeared to boost reservoir levels to the north as well at the head of the CVP system – Lake Shasta in two weeks time went from 1.5 millionAF to over 2 million as of January 12. Suddenly the lake is now half full with plenty more storms in the offing.Lake Shasta is now 70% of avenge for this date – a vast improvement.
It is happening along the Central Coast as well, where Lake Cachuma,that supports Santa Barbara,adding 61,500AF – doubling the volume in the reservoir in one day. In San Luis Obispo the Salinas Dam is spilling today down the Salinas River recharging the dry landscape in this key wine region
At Lake Nacimiento in Monterey County that supplies the City of San Luis Obispo and Paso Robles, the lake level had been at an anemic 27% on December 31 but today stands at 75% full and 175% of average. The key reservoir, less than two weeks ago, had just 100,000AF. Today the lake has swelled up to near 283,000AF!
At Folsom Dam near Tahoe regulators dumped 200,000AF since Jan 1 to make room for both high volume high elevation rain as well as an expected abundant snowpack runoff in a few months.
Here is what is happening at Eastside reservoirs that supply drought-plagued rural households, cities and farms from Madera south to Arvin.
At Millerton the lake went from 370,00AF as of Dec 30 to 431,000AF Jan12. For the 7th to 9th the biblical level deluge deposited 6 to 10 inches in upper elevations.
So the Bureau Of Reclamation vacated water down the San Joaquin River and is releasing more to the Madera Canal and some to the Friant Kern Canal, constrained by construction right now. Now at 82% of capacity, Friant Dam holds only 520,000AF.
Next down the line is Pine Flat Dam on the Kings River that saw 10 inches of rain in its upper watershed and 3.65 inches at the dam on January 9. The lake that holds a millionAF went from 225,000AF to 422,000AF by January 12 adding almost 200,00 AF in less than two weeks.
Forecasters watching the next storm say it will be colder and not as robust,good news for the snowpack.
On the Kaweah, the dam above Visalia went from a puddle to a real lake – 15,000AF to 82,000AF as of Jan 12. The Kaweah River at one point registered a runoff of 22,000 CFS on January 9.The lake is at 427% of average for the date as the warm storms brought down snow while it rained heavily below as well.
On the Tule River the Richard L. Schafer Dam went from a puddle of 5,400AF on 12/30 to 43,000AF as of January 12. Right now Success Lake stands at 327% of average for the date.The lake holds 82,000AF.
At Lake Isabella above Bakersfield storage went from about 48,000AF Dec 30, almost doubling to near 91,000AF as of January 12.
As to whether all this storminess is drought buster, reports say” the series of atmospheric river storms since Christmas has significantly reduced California’s drought, the federal government concluded Thursday.
For the first time in more than two years — since Dec. 1, 2020 — the majority of the state is no longer in a severe drought, according to the U.S. Drought Monitor, a weekly report put out by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and the University of Nebraska-Lincoln. Overall, 46% of California’s land area remains in severe drought, the report says.”
Atmospheric River targets Central California (NOAA)
Pine Flat Dam
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