The City of Fresno hadn’t bothered much recently with a mound of groundwater that accumulates beneath its southwest wastewater treatment plant every year.
For decades, it traded a chunk of the water to the Fresno Irrigation District (FID) for about half the amount back in Kings River water, but had let that deal lapse the past two years.
Then the state’s groundwater law cast that percolated sewer water in a much more attractive light.
So attractive, the city and FID are now concerned that another ag district is getting a little too handsy with it.
Farmers in the McMullin Area Groundwater Sustainability Agency (GSA), which covers a 120,000 acre portion of west Fresno County from Raisin City up to Mendota, rely almost entirely on groundwater.
Consequently, they have pumped the aquifer so hard over the years, it has created a “cone of depression” beneath McMullin that is essentially sucking groundwater away from other areas, according to documents from the North Kings GSA. North Kings covers a large portion of Fresno County north of McMullin from Kerman on the west past Clovis on the east, including Fresno City.
That outflowing groundwater includes wastewater from beneath Fresno’s southwest treatment plant.
“It is a concern,” said Brock Buche, director of public utilities for the City of Fresno. “The groundwater sustainability plan is showing that there’s a pretty large flow being pulled out from our plan area into the McMullin area. We don’t have a full understanding of what that is, but it is being evaluated.”
FID staff are also keeping an eye on McMullin’s impact on Fresno’s groundwater.
“That is something that we have discussed,” said Bill Stretch, general manager of FID. “I’ll just leave it at that.”
But McMullin staff members reject any idea that the GSA is “taking” Fresno’s groundwater.
“I think people get funny ideas in their head,” said Matt Hurley, general manager of McMullin Area GSA. “I think they’re [City of Fresno] frustrated, I guess perhaps by the fact that we kind of live in a swimming pool around here and we’re in the deep end.”
Hurley said groundwater flows to McMullin because of the natural geography of the valley and that Fresno has no claim to that water.
“Quit trying to control the resource from start to finish, you’re done with it. You put it through your wastewater treatment plant, you sunk it as part of the completion of that process, and now it’s part of the pooled groundwater for the entire subbasin,” said Hurley. “It doesn’t belong to Fresno.”
McMullin sits in the middle of the valley. That’s where water is moving to, said Hurley.
“If it’s flowing naturally underground towards the west, which it is likely to do, why would you want to interrupt that?” said Hurley. “They’re just so irritated that gravity is working against them.”
Gravity and excessive groundwater pumping, according to the North Kings GSA sustainability plan. The document estimates pumping in McMullin is inducing 45,000 acre feet a year to flow out of North Kings and into McMullin.
The North Kings plan actually states that groundwater outflows from its region should not be credited to other GSAs’ water supplies.
McMullin’s plan acknowledges some of its groundwater is coming from North Kings and states that the water is removed from its future water budget and offset by projects which will reduce pumping and increase water capture.
As the state Department of Water Resources looks over the groundwater plans, which have been revised since the state found them insufficient last January, Fresno is, apparently, taking action to keep hold of its wastewater.
It revived the exchange program with FID this summer after letting it lapse for the previous two years.
Fresno can’t use the groundwater for its own city customers because it never developed piping to transport that water into the city. So, for decades, the city traded that groundwater to nearby FID.
The city-owned wastewater treatment plant southwest of Fresno receives nearly 70,000 acre feet of wastewater a year from homes and businesses, according to Buche. That water is treated and held in ponds at the plant. Buche estimates about 60,000 acre feet percolates underground annually.
While the city isn’t able to send water from the plant to its customers, there is infrastructure in place to get it to FID. In turn, FID provides Kings River water to the City of Fresno at about 0.46 of an acre foot of river water for every 1 acre foot of wastewater, according to Buche.
He said the deal was revived this summer as the region has suffered a third year of drought. The City was “Just trying to get more water to the canals and giving more water to the city for our use as well,” Buche said.
The total amount sent to FID from Fresno this year was almost 1,700 acre feet, according to FID staff. The exchange took place throughout August.
– Danielle Bergstrom, Executive Director of Fresnoland, contributed to this report