It will take at least 2 inches of rain in much of California before any sizeable run-off makes its way into reservoirs that are at record lows.
That’s because hydrologists say the soil is so parched whether it is in the Central Valley or the high Sierra it will take that much rainfall before the ground stops absorbing moisture.
It is one of the reasons even if the water year that started Wednesday is better than the one that just ended, California could be in a significantly worse position than they are currently when Oct, 1, 2015 rolls around.
“The (weather) models I’m seeing show there is a pretty good chance we will have a fourth year of drought,” noted South San Joaquin Irrigation District General Manager Jeff Shields.
Based on aggressive conservation measures and the assumption there will be a repeat of last water year’s 60 percent of normal precipitation on the Stanislaus River watershed, Shields believes the district will be able to meet irrigation demand.
What is not known at the moment is whether a 20 percent cutback in water deliveries to the cities of Manteca, Tracy, and Lathrop will be required. Currently there is enough water in Woodward Reservoir to meet the needs of the three cities through March 1 based on last year’s consumption rates. The cities had been required in August and September to reduce the water taken from Woodward Reservoir by 20 percent from what they used the previous year.
“The one thing we can’t do is stop conserving water,” Shields said.
New Melones Reservoir was at 21 percent of capacity as of Wednesday. The reservoir holds 2.4 million acre feet of water.
The 2014 water year was one of the driest on record, with the state getting less than 60 percent of the average precipitation, according to the state Department of Water Resources.
The state’s major reservoirs collectively held only 57 percent of average water storage on Sept. 1.
Department Director Mark Cowin said “day-to-day conservation — wise, sparing use of water — is essential as we face the possibility of a fourth dry winter,” which is typically California’s rainy season.
Water officials say recent storms, while encouraging, haven’t eased the state’s water woes and forecasters can’t predict if California will get enough major storms to end the record drought.
Earlier this year, Gov. Jerry Brown declared a statewide drought emergency and called on residents to reduce water usage by 20 percent. The state and federal government have drastically reduced water deliveries to Central Valley farms, and the state water board approved fines of up to $500 for wasting water.
In September, the governor signed legislation that would for the first time regulate groundwater in California, prompted by concerns that increased pumping is depleting aquifers and causing land to sink.