The Southern Nevada Water Authority has completed two years of test pumping designed to show whether an area that is home to an endangered fish can withstand the strain of large-scale groundwater development nearby.
Now it’s up to the state’s top water regulator to analyze results of the test and decide whether the authority and others should be allowed to pump even more water from beneath Coyote Springs Valley, about 70 miles north of Las Vegas.
The authority spent $36 million to build a treatment plant and a pipeline from its Coyote Springs Valley well to the Moapa Valley Water District’s system, 16 miles to the east.
The test began in November 2010 and wrapped up last December after the authority had pumped almost 8,000 acre-feet of groundwater, enough to supply 16,000 Las Vegas homes for one year.
None of the water went to the stalled Coyote Springs development nearby, though the developer pumped about 2,400 acre-feet of water for its own use during the test period.
The authority delivered its groundwater to the water system serving the towns of Moapa, Logandale and Overton. The Moapa Valley Water District then released an equal amount of water into the Muddy River to flow downstream to Lake Mead, where the authority got to bank it for future use.
Measurements were taken at 81 locations to track potential impacts from the test. Water authority spokesman J.C. Davis said the water level dropped roughly 9 feet at the production well and about 2 feet at a well roughly 100 yards away, but “all of the measurements stayed within acceptable levels.”
“It kind of demonstrates that you can manage a groundwater basin and protect the surrounding habitat, even a habitat as fragile as the one at Coyote Springs,” Davis said.
Environmentalists have warned that the authority’s plans to tap groundwater in the area could deplete or even dry up springs that feed the Muddy River and provide a home for the Moapa dace, a finger-length fish that has been under federal protection for more than 40 years.
Similar concerns have been raised about the authority’s more audacious plans to tap billions of gallons of groundwater a year across a 300-mile swath of eastern Nevada.
State Engineer Jason King, who heads the division of water resources, will decide how much more water, if any, can be safely pumped from Coyote Springs Valley.
He has given the authority and other participating parties until June 28 to file reports on the test pumping for his consideration.
The U.S. Fish and Wildlife Service, lead agency in the effort to save the Moapa dace, is still compiling data from the test.
“It’s too early to say anything for sure,” said Dan Balduini, spokesman for the service.
Davis said preliminary evidence shows some reduction in the flow from the upper stream that feeds the dace’s habitat but no measurable change in the main spring and stream system.
The dace’s entire habitat is confined to the 116-acre Moapa National Wildlife Refuge, some adjacent private land and the Warm Springs Natural Area, a 1,218-acre tract the water authority bought in 2007 for $69 million.
The wholesale water supplier for the Las Vegas Valley agreed to help protect the fish under a 2006 federal agreement allowing the authority to tap groundwater in the area.
The authority has been approved to pump up to 9,000 acre-feet a year from Coyote Springs Valley, but it has filed for another 13,775 acre-feet in water rights there.
The Moapa Valley Water District and the developer of Coyote Springs also want state permission to pump more from the aquifer.
To some, the two-year test at Coyote Springs provides a preview of what could happen if the water authority pushes ahead with its larger, multibillion-dollar water development scheme.
Davis didn’t object to the comparison.
“We thought the project was successful,” he said of the pump test.
The authority is still pulling about 3,500 gallons a minute from its well in Coyote Springs, though Davis said officials are discussing whether it makes sense to keep the pumps running when there is no immediate need for the water.
“It’s not that hard to shut it off and turn it back on again later,” he said.
This marks the first time the water authority has moved groundwater from one basin to another. If the agency has its way, it certainly won’t be the last.
Contact reporter Henry Brean at firstname.lastname@example.org or 702-383-0350.