LOVELOCK - After a crop season stunted by drought, Pershing County irrigators need a backup water resource to supplement a Humboldt River that's fed by unpredictable snowfall hundreds of miles upstream.
Rejected by local farmers years ago for its toxicity, tainted groundwater could be cleansed by modern technology and help save future crops in short water years.
This year, Pershing County farmers received only about 10 percent of their full irrigation water allotment, according to Bennie Hodges, manager of the Pershing County Water Conservation District.
Carryover storage is down to 6,800 acre-feet in the Rye Patch Reservoir, he said. Earlier in the season, Hodges advised irrigators that a minimum pool of 5,000 acre-feet is needed to keep fish alive in the reservoir. Nevada Department of Wildlife normally stocks the popular fishing spot with walleye, wipers and rainbow trout.
The viability of local groundwater as a backup for irrigation depends on affordable methods to reduce sodium, boron, other minerals and ions harmful to crops, according to University of Nevada Cooperative Extension educator and researcher Steve Foster.
Foster and Hodges are awaiting test results from the University of Nevada on two private Lovelock-Area Upper Valley groundwater wells.
"We're trying to find out what quality of water we have in some of the groundwater in the valley," Foster said. "We're also looking to see if any of the new technologies available might be able to treat it cost-effectively for use as irrigation water."
An initial report from the university is that boron levels are at or near the upper limit tolerated by alfalfa. Wheat and other small grains cannot tolerate such high boron levels, Foster said. Many other water quality factors affect crop production, including sodium, sulfate, chloride, nitrates, arsenic, alkalinity and pH.
"We don't know about the salinity yet," Foster said. "That may be a problem."
Nanotechnology filtration or reverse osmosis systems could provide an economical solution and reduce farmers' dependence on the Humboldt River, Foster said. Water quality consultants will consider the test results and recommend treatment processes.
"If you don't have to force the groundwater (through filtration), then your energy costs would be low," Foster said. "We have plenty of groundwater here but it's not
good. If we could clean that up, it doesn't have to be potable, then we could look at adding wells for irrigation water and, if it was cost effective, the farmers could put their own pivots in."
The other challenge is the long and complicated process of obtaining groundwater rights, Hodges said this week.
As groundwater is pumped for pivot irrigation, mining, residential needs and other increasing demands along the upper Humboldt River, declining aquifers are naturally recharged by the river and other surface water. That surface water diversion decreases the water supply to downstream irrigators in Pershing County, according to a long-term study of the Humboldt Basin watershed by the U.S. Geological Survey.
A few months ago, the study results were explained to Pershing County farmers who expressed concern and frustration that upstream irrigators still receive their full groundwater allotments while Pershing County irrigators suffer through the drought with a fraction of their surface water allotments.
USGS hydrologist David Berger confirmed the long-term study indicated that groundwater pumping has reduced the amount of Humboldt River water reaching Pershing County over the years.
When farmers asked if groundwater and surface water allotments could be a more equitable during droughts, Berger said that's a question for the state water engineer.
Local growers have senior water rights but that's no longer a guarantee, Foster said.
"We have water rights here," Foster said. "If a mine comes in, they get a temporary permit for a groundwater well. That permit might last 50 or 75 years so how temporary is it? When they pull groundwater out, it is taking away from our surface water, and so there are water rights issues they (state water officials) maybe need to look at."
Meanwhile, Foster and Hodges will continue the search for alternative water sources and efficient methods of water treatment and conservation.
As water flows from Rye Patch Reservoir through canals and ditches to farmers' fields, up to half is lost to evaporation, reducing the irrigation system's efficiency to as low as 50 percent, Foster said.
Pivot irrigation using groundwater would provide greater water efficiency but utility costs would increase. Farmers are currently paying about $28 to $29 per acre to operate their relatively low-power irrigation system, he said.
"If you're pulling it from the groundwater, you have more control over when and how much water you use," Foster said. "The problem is the cost of the electricity for pumps and other equipment. It's more expensive than the little irrigation gates we have now."
As a result of the water shortage, farmers had to pick and choose their best-producing fields while sacrificing crops planted months earlier. Stunted wheat became cattle feed and lower quality alfalfa production resulted in lower prices for farmers, Foster said.
Hodges said he's waiting for the university's water tests results, paid for by the district. There are numerous old wells in the valley, but most have been capped or were allowed to cave in years ago due to the poor ground water quality, he said. Deeper wells might yield better results but only if the irrigation district could obtain the rights to that groundwater.
"I'd have to try to apply for them (groundwater rights) but it's very involved and I don't know what the availability would be," Hodges said. "It's too early to speculate on what could happen. That's what hurts us here - we don't have any supplemental water."
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