FURNACE CREEK, Calif. -- Comments by Lise Comartin, a graduate student creating a Pahrump groundwater flow model for the Desert Research Institute, at the annual Devil's Hole workshop last week, were alarming.

Pahrump is still pumping about 25,000 acre feet of water per year, she said, which is above the annual recharge of 19,000 acre feet per year from the Spring Mountains, as determined in a benchmark 1986 study by Jim Harrell, she said.

"Which raises the question: it's not going to be if Pahrump will run out of water, it's when you will run out of water," Comartin said.

The highest rate of withdrawal of water was in the 1960s, when alfalfa and cotton farmers pumped 49,000 acre feet of water annually, Comartin said. An acre foot is 325,851 gallons, enough to fill up an acre of land a foot deep, or enough water to provide for a family of five for a year.

Water usage dropped when Pahrump shifted from agricultural to domestic wells, Comartin said. Nevertheless, she said the population has "just exploded" since then from a few thousand people to close to 40,000 people today.

"With a population growth of about another 10,000 people by 2050, water resources are obviously of great concern in these studies. It's also the most heavily allocated groundwater flow system (in Nevada) with approximately 10,000 domestic wells," Comartin said.

The DRI study will provide Nye County with an updated model to use for water management decisions, Comartin said.

"This will provide the framework for future studies addressing subsidence and the optimization of well placement in Pahrump in the future," she said.

Nye County hydrologist Tom Buqo said when a developer, for example, wants to move a bunch of water rights to a single point of diversion, the Nevada Division of Water Resources can plug in the data from the groundwater flow model to determine what the long term effects will be.

Buqo, who didn't make a presentation at this years conference, said he's advocated drilling wells on the alluvial fan to prevent subsidence in the basin.

The DRI study will calibrate recharge rates, pumping rates, evaporation rates and other information, Comartin said. She estimated the rate of evaporation at between 11,300 and 12,500 acre feet per year.

There are few long term, monitoring wells in Pahrump, most of the data comes from 1966 to 1976, she said.

An abstract of Comartin's presentation includes the statement: "the strain placed on the groundwater system through unsustainable, groundwater extraction rates threatens the future viability of the basin fill aquifer in meeting water demands."

Comartin uses a higher rate of recharge into the Pahrump aquifer from the Spring Mountains, 31,000 acre feet per year, using a formula devised in studies done in central and northern Nevada about 15 years ago. She calculated mean annual precipitation in the mountains to net infiltration.

Buqo said there is a secondary recharge into the Pahrump aquifer, which raises the annual recharge from 19,000 to about 26,000 acre feet per year.

Water recharge comes from the Spring Mountains, flowing into one of two aquifers, Comartin said. Don Sweetkind, from the U.S. Geological Survey, determined there were 14 different geologic types in Pahrump Valley during a 2003 study, which will be useful in drawing up the model, she said. Data from a Death Valley regional flow model will also be used.

Despite the dropping water table -- Buqo estimated previously the water level was dropping at an average of one foot per year valley-wide -- Comartin said mesquite trees are flourishing in Pahrump.

"That's quite surprising since the water level here is between 50 and 70 feet below the surface," Comartin said.

During an interview after her talk, Comartin echoed the concerns raised by Buqo previously, that many well owners in Pahrump will have to re-drill their wells between the year 2030 and 2040 if water levels continue to drop.

"Eighty percent of the domestic wells are between 140 and 150 feet. So they're not that deep, but a lot of people are probably going to have to re-drill wells," Comartin said.

Her advice: just conserve as much water as possible starting now.

"I'm from the East Coast. We conserve sometimes more than people in Nevada," Comartin said.

Darrell Lacy, director of the Nye County Nuclear Waste Project Office, which commissioned the DRI study using a federal groundwater evaluation grant, said Comartin will make a presentation to the newly-formed Nye County Water Board on the results of the study sometime in the future.

The next meeting of the water board is scheduled at 10 a.m. May 26 at the Bob Ruud Community Center.

The DRI was also awarded a $80,100 contract May 5 to study the chemistry of ground water in Pahrump and Amargosa Valley. That will help define water quality in Pahrump and help resolve flow paths to Devil's Hole, where federal water managers protest water rights applications, according to Lacy's summary to county commissioners.