The Oakdale Irrigation District has significantly increased its groundwater pumping around Valley Home, but the water agency’s staff has concluded that OID is not to blame for wells running dry in that rural community.
OID directors will discuss the region’s groundwater woes at their 9 a.m. Tuesday meeting, responding to concerns raised by Valley Home residents.
Pumping records show OID’s nine wells around Valley Home pumped more than 3,265 acre-feet of groundwater for irrigation from January through June this year. That’s 84 percent more than was pumped during those same months last year and 144 percent more than during those months in 2012.
Several Valley Home residents have reported their wells have gone dry – or just about – this summer, and they’ve turned to OID for help.
But the public agency’s staff has determined “it is with certainty OID is not a cause of the dropping groundwater level in the OID.”
That staff report analyzed the impact of pumping for two of OID’s Valley Home wells, and it concluded those two wells were responsible for dropping the aquifer’s water level by 10.8 inches during the first six months of this year.
OID called such a groundwater decline “insignificant.”
The impact of pumping from OID’s seven other wells near Valley Home was not included in the report.
The two wells OID analyzed pumped about 897 acre-feet of water during those six months, while the other seven Valley Home wells pumped an additional 2,368 acre-feet, the district’s well logs show.
One acre-foot of water is considered enough to meet the domestic needs of four people for one year. Valley Home had 228 residents as of the 2010 census.
OID’s report said groundwater levels have been falling in Valley Home since 1940.
“The trend line indicates that a 100-foot well dug in the mid-part of the 19th century, with bowls set at 95 feet, would have reached the end of its useful life in 2013 or 2014,” the report concluded. “The drought may have accelerated the loss of a shallow (well in Valley Home) … but it is clear that the useful life cycle of a shallow well as described has been reached.”
General Manager Steve Knell said OID’s wells near Valley Home are 300 feet deep, while the depth of most of the community’s private wells are thought to be 100 feet or less.
Pumping by local farmers also may be partly to blame for falling groundwater levels, according to OID.
But the district said it “cannot control or assert authority over individual landowners who are exercising their property rights to pump groundwater.”
Unlike most other irrigation districts, OID has not reduced water allocations to its farmers during this three-year drought.
Knell said OID is on pace to deliver about 235,000 acre-feet of water to its 57,000 acres of farmland, which is just slightly less than average. Knell said his district also expects to pump about 15,000 acre-feet of groundwater this season – about 7,000 more than during a typical year – to bolster its surface water supply from New Melones Reservoir.
OID directors on Tuesday will consider extending this year’s water delivery season past Sept. 30.
“Some farmers, especially those with orchards, like the option to irrigate once in October,” the district explained in a press release.
For Valley Home residents who think their ability to access groundwater for their families has been impacted by OID’s pumping, Knell’s staff report suggests filing a claim with the district’s insurance carrier.
The OID board of directors will meet at 9 a.m. Tuesday at the district office, 1205 E. F St., Oakdale.
Copies of OID’s well pumping logs for 2012, 2013 and 2014, plus descriptions of where those wells are located, are posted with this story on www.modbee.com.