H2O gurus seek ways to refill
aquifer
Recharge could cost millions;
take decades to see spring flows
By GREG STAHL
Express Staff Writer
As a tool to help alleviate a
water pinch in the Snake River Plain aquifer, recharging the underground
reservoir using surface water will be costly and require diligence from
the project’s proponents.
"Some of the bigger sites could
cost $600,000 to $1 million," said Idaho Department of Water Resources
Recharge Project Coordinator David Blew. "There would probably need to
be state money to make it work.
Furthermore, many potential
recharge sites are on land managed by the Bureau of Land Management and
would require land exchanges and time-consuming and costly environmental
analyses to approve.
"It is not a panacea," Blew said.
"It is not a silver bullet. It is another tool in the toolbox that we
have to look at."
Blew and Alan Merritt, a regional
manager with IDWR, met Tuesday night in Fairfield with members of the
Wood River Watershed Advisory Group during the water board’s monthly
meeting.
The catalyst for the presentation
and discussion Tuesday was a winter-long dispute between Hagerman Valley
fish farmers and Snake River Plain groundwater pumpers.
"Okay, we’ve got problems,"
Merritt said in kicking off his presentation.
He pointed out that flows from the
so-called Thousand Springs, aided by surface irrigation on the plain,
peaked in the 1950s. Since then, development of groundwater pumping
irrigation systems on the plain—among a myriad of other causes,
including drought, adjustments in canal operations and more efficient
pumping—has diminished the amount of water issuing from the Hagerman
area springs.
In response to the problem, the
state's chief water manager on Feb. 25 ordered Magic Valley wells on the
north side of the Snake River to shut down unless water users could come
up with replacement water for a Hagerman-area fish hatchery that is
suffering water shortages.
The shutdown was scheduled to
apply to wells developed after July 13, 1962.
Idaho Department of Water
Resources Director Karl Dreher's order would have affected groundwater
users in Water District 130, which runs from Gooding and Minidoka
counties into Lincoln County.
"The director, he struggled with
this determination," Merritt said. "He didn’t do it lightly. I think you
have to give Mr. Dreher credit for doing that, quite frankly."
The premise of the decision lies
with the interconnected nature of the Snake River Plain Aquifer and the
rivers and springs that feed it, and rise from it.
The problem is that ground water
has been depleted to the point that it is detracting from springs in the
Hagerman valley, where parts of the aquifer have historically dumped
into the Snake River. Several Hagerman fish hatchery operators filed
with the Department of Water Resources last year because the water they
draw from springs had been diminished.
A call by Rangen, Inc., a fish
farm with the most senior water rights of those who made a "call" for
water, took center stage. Rangen’s water right priority, July 13, 1962,
is the date Dreher used as the proposed cutoff for the plain’s
irrigators.
But before ground water pumping
was curtailed this spring, the state of Idaho entered into an agreement
with the Magic Valley Ground Water District, the North Snake Ground
Water District and spring users in the Thousand Springs reach of the
Snake River. The temporary solution the groups reached was to pump water
and money into the Hagerman area this year, and to continue looking for
long-term solutions. As another part of the solution, an interim
legislative committee is performing an ongoing search for solutions.
"I think everything’s on the
table," Merritt said, adding: "If large-scale managed recharge was easy,
we would already be doing it."
There are three operational
recharge sites on the Snake River Plain, Blew said.
"We’ve got a whole lot of others
on the drawing board," he said. "Part of the challenge is that we’re
looking for some sort of organizational structure. As we go through this
process, we’ll figure out the best organizational structure to carry
this out."
For starters, it would take time
for aquifer recharge to trickle through the system. If 416,000 acre feet
of water were pumped into the aquifer each year, spring flows in the
Hagerman reach of the Snake River would increase by 350 to 400 cubic
feet per second in 20 years, Blew said.
It’s no coincidence, then, that
416,000 acre feet is the amount of water that could be accommodated by
the Milner-Gooding and North Side canals.
"It’s what they’ve used to model a
lot of this stuff on," Blew said.
It’s also no secret that there
will be lean water years when recharge does not occur. Conversely, in
wet years, the powers that be would have to be prepared to get
operations underway.
"In the years when water is
available from the rental pool, we’re going to have a lot of water,"
Blew said.
The timeframe under which recharge
might begin to occur on a meaningful scale, however, is fuzzy. It
depends on a myriad of pieces falling correctly into the ever-changing
puzzle.
"I hesitate to say what the time
frame’s going to be," Blew said. "I would say that we have to make
progress in the next couple of years to make this work. The big thing
that’s going to dictate when we’re going to do this is when we have
water."
The Snake River Plain Aquifer is
one of the largest aquifers on earth and extends for 12,000 square miles
beneath the Snake River Plain. It is fed primarily on its northern and
eastern peripheries, from the mountains of Central Idaho and the eastern
edge of Yellowstone National Park. The Snake River flows along the
southern margin of the plain, fed by tributaries flowing out of the
mountains on the south and east sides of the plain.
The aquifer discharges primarily
in two locations: Near American Falls Reservoir, the aquifer empties
through springs at about 2,600 cubic feet per second, and near Hagerman
at about 5,200 cubic feet per second.