SALT LAKE CITY — Utah's record-setting snowpack in the mountains is all but gone, but its impacts may play out for decades to come by boosting groundwater levels in basin-fill aquifers.
To what extent aquifers have "recharged" or filled as a result of this year's voluminous snowpack combined with an incredibly wet spring will provide valuable information for hydrologists and those charged with oversight of the state's water supplies.
Scientists at the U.S. Geological Survey in partnership with the state Division of Water Resources and state Division of Water Rights want to take the data they already gather from hundreds of wells to look at impacts from this high precipitation year. The information could also be applied in surrounding states such as Montana, Colorado, Idaho and Wyoming, which have seen high snowpacks this past season.
"For long-term water use, this is quite important," said David Susong, a hydrologist with the survey's Utah Water Science Center. "We are working on a proposal to really analyze this event and do a retrospective of the 1982, ′83 and ′84 water years."
That was the last time Utah was hit hard with high snowpack that fed a high springtime runoff.
"What we saw then," Susong said, "in the major basin-fill aquifers is that we had a significant recharge event."
In central Utah's Phavant Valley, for example, Susong said the high water years in the 1980s reversed 30 years of decline in an aquifer's water levels.
"It varies with the basin, but there you had a 20 to 40 feet of water level rise."
The study, which hinges on getting the funding, will help Susong and others better understand aquifers, their recharge, and the extent big snowpack years have on boosting those levels.
"We may be much more dependent than we believe on these big recharge events for overall groundwater supplies," he said. "As the frequency of these big recharge events changes over time, that may change the amount of water that is available in the future."
Susong likens it to a big lottery check deposited in a bank account that will support household spending.
"We need to know how much we can live on this in the years to come and when that next big lottery win is going to happen."
Understanding that is critical, emphasized Dennis Strong, the state's director of Water Resources, since so many cities depend on aquifer-fed springs and wells for culinary water supplies.
With high precipitation years like the one Utah just experienced, water managers are looking increasingly at ways of hanging on to that excess water to see the state through drier times.
A man-made aquifer has been created at the mouth of Weber Canyon in a gravely area in which water from the Weber River is seeping into the ground.
The artificial recharge project, through a technique called spreading, is designed to augment ground water supplies, Strong said.
Such ways to boost groundwater supplies have become more important because water is a finite resource in the midst of growing demand.
Boyd Clayton, the state's deputy water engineer, said it's getting to the point in most basins where any new withdrawals are being limited.
As the agency tasked with managing water supplies at sustainable levels, the state Division of Water Rights has to balance current demands against long-term need, he said.
Some basin aquifers are already tapped out and understanding the time period — that interval between recharges — will help officials determine how much water can be withdrawn at a rate that can be sustained.
"It's an exact science with inexact information," Clayton said. "The aquifers are all recharging all the time, but the trick is to know exactly how much they are recharging and long-term, what are those rates. "
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