CARSON CITY – Opponents of a proposal by the Southern Nevada Water Authority to pipe rural Nevada groundwater south to quench the thirst of Las Vegas got their chance to argue against the project today before State Engineer Jason King.
Opponents, including Utah officials, the Great Basin Water Network and the Confederated Tribes of the Goshute Reservation, have been given through Nov. 15 to make their arguments that the request for 125,976-acre feet of groundwater in Delamar, Dry Lake, Cave and Spring Valleys would harm the environment and economic viability of rural Nevada and Utah.
Much of the hearing today focused on concerns by Utah officials that tapping the groundwater from southern Spring Valley in Nevada would adversely affect water resources in the adjoining southern Snake Valley that straddles the Nevada-Utah state line.
Hugh Hurlow, a senior scientist with the Ground Water & Paleontology Program for the Utah Geological Survey and a witness for Millard and Juab counties in Utah opposed to the applications, testified that his analysis shows that pumping from southern Spring Valley could potentially cause groundwater levels to decline in the Snake Valley because of the interbasin flow that now occurs from west to east.
The flow from southern Spring Valley to the southern Snake Valley is estimated at between 4,000-acre-feet to 33,000-acre-feet per year, he said in his testimony.
Using the lower range of the estimates for his calculations, Hurlow said he estimates that between 10 percent and 25 percent of the southern Snake Valley groundwater comes from the interbasin flow from the west from southern Spring Valley.
This would adversely affect well levels and springs in the southern Snake Valley which is already under stress due to agricultural and other uses, he said.
“So that is why I think that a reduction of the interbasin flow from Spring Valley to Snake Valley could have adverse effects to the groundwater system in Snake Valley,” Hurlow said in response to questioning from Mark Ward, the attorney representing the Utah counties in the proceedings.
He also argued that if water rights are granted, that a proposed monitoring system include test wells in Utah that would need to be operated for several decades to track any changes in groundwater levels and flow.
Attorney Paul Taggart, representing the water authority in the hearing, noted that the agency has asked the state engineer to include such a monitoring program if water rights applications are granted.
He also cited two studies suggesting the interbasin flow is no more than 4,000-acre-feet annually. Only one study suggests the flow is greater than 12,000-acre-feet, Taggart said.
Pat Mulroy, general manager of the authority, said in opening arguments in September that the plan to acquire unappropriated groundwater rights in rural Nevada to supplement Southern Nevada’s supply of Colorado River water is essential to the economic future of the region.
Southern Nevada needs to ensure it has a diverse supply of water for that time in the not-so-distant future when the states sharing the Colorado River basin fully use their allotments, she said. The river is over-appropriated and a prolonged drought could create a shortage in coming years, Mulroy said.
Opponents argue that more conservation and the pursuit of desalinization plants would be better alternatives to taking the groundwater.
Mulroy said the agency has taken aggressive steps to improve conservation efforts, including a turf reduction program, and that environmental issues make the desalinization option unlikely to become available in the near term.
Even if the water applications are granted, it would be at least 10 years before construction of a pipeline costing an estimated $7 billion would move forward, Mulroy said.
Hugh Hurlow, a senior scientist with the Ground Water & Paleontology Program for the Utah Geological Survey, says Spring Valley groundwater flows into the Snake Valley:
Hurlow says about 10 percent to 25 percent of the southern Snake Valley water comes from the Spring Valley to the west:
Hurlow says that is why there could be adverse impacts on the southern Snake Valley:
Southern Nevada Water Authority attorney Paul Taggart says most studies show smaller amounts of interbasin transfer: