Oakdale’s Woodward Reservoir, a popular recreation area, could potentially be closed this summer, depending on what the South San Joaquin Irrigation District Board of Directors decides at its upcoming Tuesday, Feb. 25 meeting where it’s expected that the action item and discussion on the lake’s level will appear.
SSJID constructed Woodward and has independent storage rights, using it as a regulating reservoir for irrigation and also has a water treatment facility there. SSJID General Manager Jeff Shields reported that SSJID diverts water at Goodwin Dam through a canal that goes into the reservoir for irrigation and drinking water for the cities of Manteca, Lathrop, and Tracy. He noted that Woodward is fairly shallow and when water is added, the lake spreads out.
“When we fill it up, it costs (the district) 35,000 acre feet of water,” Shields said.
That loss is due to seepage and evaporation. Woodward Reservoir’s maximum capacity is 36,000 acre feet, nearly equal to the amount of water that’s lost over the course of a year by keeping it full, he said, and SSJID would like to cut that loss.
Shields said that there are two intakes for the reservoir. The upper intake is an elevation of about 210 feet and the lower is about 192 feet.
“If we can keep water in the lower intake, we can save about 9,000 acre feet – which is an irrigation run,” he said. “In a year like this it’s important for our farmers and cities.”
He said there is a lot of value in 9,000 acre feet of water. He noted that if they have to pump groundwater to make up for it, it’s very expensive; or to buy it on the open market now, at a cost of around $400 per acre foot for a total of about $3.6 million, that is not something that they do.
If the SSJID board decides to keep the reservoir at the lower intake level, the minimum amount would be 10,944 acre feet. Shields said that if they take that action, they’d probably actually keep the level around 12,000 to 13,000 acre feet.
Shields acknowledged that Woodward Reservoir revenues represent a substantial piece of Stanislaus County Parks and Recreation Department’s total budget.
He said the question becomes: do they fill it up for recreation or for their customers? He noted that there’s going to be minimal recreation in probably every reservoir in California this year and referenced New Melones Reservoir’s plans to close its marina. He also said that no one wins in a year like this.
Shields explained that in a normal water year, SSJID fills up the reservoir after the beginning of March to about 210 feet elevation. The water has to go through a “water quality wall” and doesn’t flow back and then people can recreate on the lake. However, SSJID is required to lower the reservoir in the winter to 192 feet and at that level no bodily contact is allowed for water quality reasons. No bodily contact means no one can be in the water.