Posted on Tue, Jan. 24, 2012

Irrigation canals will start to shut down this week after temporarily providing critical relief because of this winter's late-arriving rain.

Water deliveries will end Thursday in the South San Joaquin Irrigation District, which had started them Jan. 15.

The Modesto Irrigation District plans to supply water through Friday, ending a 2½-week run. The Turlock Irrigation District plans to go through Saturday, a total of 10 days.

The Oakdale Irrigation District will continue to make its large wells available to farmers until the regular irrigation season starts, if needed.

Canals were refilled during their usual winter shutdown because of a nearly rainless spell stretching to November.

"Here we are a full month into our winter, and we've hardly had a taste of it," said Walt Ward, the MID's assistant general manager for water operations, at Tuesday's board meeting.

Farmers who lack wells asked the districts for the canal water so they could irrigate winter feed crops, along with fruit and nut trees preparing to bloom.

The storms from Friday to Monday brought Modesto up to about half of its average annual rainfall for this time of year.

The snowpack in the central Sierra Nevada stood at 34 percent of average Tuesday, according to the California Department of Water Resources. It was 6 percent a week ago.

Water stored from last year's big storms has helped stave off concerns about shortages this year. Don Pedro Reservoir on the Tuolumne River stood at 112 percent of average Tuesday, the state agency reported. New Melones on the Stanislaus River was at 143 percent.

The MID has delivered about 8,500 acre-feet of water to farmers this month, Ward said. An acre-foot covers an acre a foot deep.

Ward said an additional 3,000 acre-feet spilled out the ends of canals into streams — water that was needed to fully charge the system but was not used for crops.

The MID supplies about 185,000 acre-feet to farmers in a typical year, along with about 35,000 acre-feet to the city of Modesto and a few other communities.

The TID, more than twice the size of the MID, planned to put about 25,000 acre-feet into the canals this month, spokesman Herb Smart said. It has not yet determined how much excess water will spill, he said.

The demand for water continued even with the rain, SSJID spokeswoman Troylene Sayler said.

"The recent storm was very helpful as far as rain and snow in the upper elevations, but the rain here only saturated the top level of soil, so our growers are continuing to take our water," she said.

Bee staff writer John Holland can be reached at jholland@modbee.com or (209) 578-2385.