Farmers can expect 40 to 60% Sierra runoff

To date the Bureau of Reclamation announced contractors will get 40% of Class 1 supply

By John Lindt
Sierra 2 the Sea News Service

TULARE COUNTY – Valley saw close to double the average river runoff last year but in 2020 it could be as low as quarter of that – perhaps 50% of average.

Runoff on the San Joaquin River is estimated at 720,000 acre-feet, 59% of average. But to date the Bureau of Reclamation has announced just a 40% Class 1 supply to contractors.

On average, the Friant delivers 1.2 million acre-feet of irrigation water annually through the Friant Kern Canal and the Madera Canal to more than 15,000 farms on over a million acres including those in Tulare County.

Despite an announcement by the Bureau of Reclamation that due to a dry water year in northern California, Lake Shasta will not be able to supply 100% of contracted water to the San Joaquin River Exchange Contractors, although Friant Water users are not expected to be impacted.

An April 13 update from the Bureau stems from a recent determination of a “Shasta Critical Year,” a term defined in specific water contracts. In general, a Shasta Critical Year occurs when the forecasted inflow to Shasta Lake for a particular water year is equal to or below 3.2 million acre-feet.

“While we were all hoping for a ‘miracle March’ after February landed as record dry, we were not so fortunate,” said Bureau of Reclamation regional director, Ernest Conant. “Although March did bring some wetter weather across California, it ended up being relatively dry for Shasta inflow.”

Among the contractors affected are the Los Banos area San Joaquin River Exchange Contractors and San Joaquin River Settlement Contractors who are now down graded to approximately 75% of their contract supply.

The 150-mile Friant Kern Canal gets all its supply from the upper San Joaquin River and Vink estimates this year water users could get just 40 to 50% of average supply. ”Whatever we get from the San Joaquin we will be able to keep”  and not give up some to the Los Banos farms.

Friant spokesman Johnny Amaral agrees but expects the Bureau to upgrade their 40% declaration due to a wet March. This coming week «looks like we’re heating up” to irrigation season quickly.

Vink says last year was an abundant supply year and expects this year farmers can tap groundwater to make up a decline in surface supply.

Last year Friant contractors got 100% of Class 1 supply.

South Valley watersheds

This week farmers counting on irrigation supply from their watersheds took stock of what runoff might look like this summer. Despite forecasts, estimates may be revised based on snowpack.

Tule River runoff 

Tule River runoff is estimated to be 46% of average this year says the Department of Water Resources in their April 14 update. Vink, whose districts are in southern Tulare County says Success Lake has about 25,000 acre feet in storage. It holds 80,000 acre feet. In an average years it yields 63,000 acre feet downstream. Vink expects this year it might yield just 20%.

Kaweah River outlook

Runoff on the Kaweah River is expected to be 54% of average for April to July says Kaweah Delta Water Conservation District operations supervisor Victor Hernandez. That is about 155,000 acre feet. That compares with last year’s 182% of average in what was a very wet year. The good news is that most water not used for crops was recharged in basins around the district or it is in the reservoir says Hernandez. The river runoff on average is about 440,000 acre feet.

Kings River forecast

The April 14 DWR bulletin pegs Kings River runoff (50% exceedance) at 56% of average. But Kings Watermaster Steve Haugen says Kings River Water Association uses an estimate that takes into consideration data from multiple surveys of the watershed, snowpack and coming storms. He comes up with 60% of average, perhaps even a bit higher for this water year.

Last year Kings River runoff was 176% of average. The good news is that of the 3 million acre feet that was delivered – only 120,000 acre feet was not retained—flowing to the sea. Pine Flat has nearly 600,000 acre feet now. The big reservoir holds one million acre feet.

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