Merced Irrigation District to pump less groundwater

The Merced Irrigation District expects to pump significantly less groundwater this year than it did last year, in part because the irrigation season will be about eight weeks shorter.

“Our projected total is to pump just over 40,000 acre-feet,” district General Manager John Sweigard said.

His district pumped more than 56,700 acre-feet of groundwater during 2013. By comparison, it pumped 33,465 acre-feet this January through June.

Those wells will stop pumping the first week of September, which is sooner than normal. That’s when the drought will force the Merced district to stop providing irrigation water. During normal weather years, its water deliveries continue through October.

But this is far from a normal year. The drought has seriously depleted the irrigation district’s supply of surface water from Sierra snowmelt and runoff.

Merced’s 100,000 acres of farmland will receive just over one foot of surface water per acre from the irrigation district. And those farmers will pay $75 per acre-foot for that water.

Sweigard said the groundwater his district pumps this year will enable farmers to buy up to an additional four inches of water, but they will be charged $110 per acre-foot for it.

There are widespread concerns about the overpumping of groundwater throughout the San Joaquin Valley, and Sweigard said he is worried about the Merced groundwater basin being depleted.

About 20 percent of the Merced Irrigation District’s wells no longer work, and Sweigard said “it’s definitely the dropping water level” to blame for most of those well failures.

“There are a lot of straws in the ground, both inside and outside the water district,” said Sweigard, noting that his district covers only 20 percent of the Merced water basin.

Most of the district’s wells are near Livingston, Atwater and south Merced.

“We only pump when we absolutely need to,” Sweigard assured. “The conversation about sustainable groundwater management is overdue. … We’re all for it.”

The Merced Irrigation District, however, has pumped a lot more groundwater the past two years than it had the previous four years. Between January and June this year, it pumped more groundwater than it had during all of 2009, 2010, 2011 or 2012. The district’s pumping levels were much higher in 2007 and 2008.

Despite the recent increased pumping, Sweigard said, his district calculates it contributes more water to the basin through canal seepage, field drainage and other forms of groundwater recharge than it pumps out.

The district usually has enough irrigation water to sell its surplus. From 2004 through 2013, it sold more than 617,000 acre-feet of water to buyers outside the district and collected nearly $56.4 million for it.

This year, however, it sold just 5,000 acre-feet of water for $5 million.

Sweigard said that water could not have been used for irrigation because it was required to bolster Merced iver flows this spring to benefit salmon and trout. After that water flowed downstream, it was sold to the Santa Clara Valley and San Luis water districts.

Related stories from Modesto Bee