Late-winter rain has prompted the Oakdale and South San Joaquin irrigation districts to postpone the start of their 2014 deliveries to next week.
Both had planned to begin filling canals Monday, which was somewhat early because of the mostly dry conditions this year, but the recent storms brought a change. OID now plans to start next Monday, and SSJID will follow March 12.
“We pushed it back a week due to the rain we received as of last Friday,” OID General Manager Steve Knell said. More rain and snow are possible this week, according to the National Weather Service.
The Modesto and Turlock irrigation districts plan to start deliveries in late March to conserve their supplies, which are tighter than in OID and SSJID. The Merced Irrigation District, which is in even worse shape, has not set a start date but likely will shorten its season.
Storms this time of year do two things: They top off the Sierra Nevada snowpack, which supplies most of the Northern San Joaquin Valley’s water, and they slow irrigation demand by moistening the soil.
Despite the recent storms, the central Sierra snowpack is only 37 percent of average, the California Department of Water Resources reported Monday. And reservoir levels were drawn down to deal with the below-average rain and snow in 2012 and 2013.
The Modesto and Turlock districts plan to deliver a little less than half of the accustomed amount of water to assure that at least some is carried over in Don Pedro Reservoir for 2015. The Merced district faces the prospect of running out of its Lake McClure storage this year. All three plan to increase groundwater pumping, as does OID.
Oakdale and South San Joaquin, which share reservoirs on the Stanislaus River, are in better shape than most districts thanks to strong water rights, adequate storage and past conservation projects. But officials said they are conserving in case next year is dry, too.
The weather service predicted a 70 percent chance of rain in Modesto on Monday night and early today. It sees a strong chance of more rain Wednesday night and Thursday.