It's just a matter of time before the Town of Payson has a damaging effect on the wells of Diamond Star residents by using that community's water to fuel its growth, according to a team of hydrologists who spoke at a Diamond Star Town Hall meeting Tuesday evening.
The damage is the inevitable result of Payson's decision to pipe 530 gallons per minute from a well in Star Valley down the Beeline to the Payson water system.
"It's happened all around the state where they have pumped (groundwater) -- aquifers now run dry," said Brad Cross, vice president and principle geologist for LFR Levine Fricke, the hydrogeology firm retained by Diamond Star to conduct a safe yield study of the town. "If the amount of water you're extracting from the aquifer exceeds the recharge, groundwater levels will continue to decline.
"Ultimately springs will dry up, water tables will drop -- sometimes destroying vegetation -- and wells will continue to decline until they can no longer be pumped. Those are things you can anticipate happening."
Cross and LFR Field Engineer Vit Kuhnel, Ph.D., who also spoke at the meeting, said that their safe yield study will confirm the impact of the pumping, but they are sure it will happen.
"They won't be able to sustain it without affecting everybody around them -- and their own well," Kuhnel said. "They're going to lower the water table to below the pump intake."
As evidence, Kuhnel cited tests done by the Arizona Department of Transportation (ADOT) on five wells near Diamond Point that were used in the construction of Highway 260.
"For comparison, in the ADOT study, they were pumping 350 gallons per minute from the five wells simultaneously," Kuhnel said. "They dried up one creek and they lowered wells in Diamond Point Shadows by 20 to 100 feet. Any pumping you do has to pull water from somewhere."
Kuhnel said the ADOT studies were especially valuable, not only because of their thoroughness, but also because the geology of the area where they were drilled is very similar to that of Diamond Star.
Cross also challenged the Town of Payson's claim that it will be drawing on a separate and deeper aquifer than that tapped by the current wells in the Diamond Star area. He attended the recent meeting on the U.S. Bureau of Reclamation's Water Resources Management Study held at the Payson Public Library.
"One of the problems with the studies I saw last week is they only tested one well in Star Valley, and it's a very shallow well," he said. "The chemistry of that water would be similar to very shallow water.
"From that one well they made the assumption that all of Star Valley is just shallow, recent water and is not connected to the deep aquifer. It'll be interesting to see when that report comes out whether they've done more investigating."
During a question and answer session following the LFR presentation, an attendee asked Cross whether he would be concerned if he lived in Star Valley "given the information that you have today,"
"(With) the volume of the water they're planning on pumping, I would be concerned -- yes," Cross responded.
The LFR team spent the day before the meeting surveying well sites for their safe yield study. They were accompanied by Diamond Star Town Councilor Chuck Heron and other members of water task force appointed by the Diamond Star Town Council.
"We did some soundings on wells around the area," Heron said. "We went up and visited the Randall-Haught well. We made the rounds to determine which wells we're going to put probes down."
That study, which should be completed in two months, will ultimately confirm their assessment, Cross and Kuhnel believe.
"Right now there is a big well right across the street (from the church) within a month of production," Kuhnel said. "We want to know what impact it's going to have on the groundwater."
"We don't know how much storage is available in that aquifer and we don't know how much recharge you have," Cross added. "Those are things we need to find out before you can make estimates of how much you can really pump without having those kinds of damaging consequences."
Heron, who chaired the meeting, closed by linking the area's water supply to quality of life -- an aspect of the issue he says is seldom considered.
"In Payson they're balancing the amount of recharge with the amount that is taken out (through conservation)," he said. "They're basically telling people you cannot use water for this and that.
"The way they're going, it could end up with the west side of Payson taking their showers on Monday, Wednesday and Friday, and the other side of town taking them on Tuesday, Thursday and Saturday. You'd still be at safe yield, but is this the quality of life you want to have?"