One of the Gem State's most valuable treasures
is hidden from view. Beneath the surface of
the ground is a billion acre feet of water;
enough water to create a lake 140 feet deep.
Political specialist Doug Andersen has more on
the state's largest aquifer.
As the State Water Resources Board meets to
formulate a plan to manage Idaho water, one
component is the aquifer. What is it? And what
does it do?
Jerry Rigby, chair, Idaho Water Resources
Board: "One could say it's like a huge
reservoir that, in essence, water goes in and
water comes out."
It's 4,000 feet deep in spots, and the
Eastern Snake River Plain Aquifer is made
mostly of basalt. The combination of rock and
sediment yield water. Not like a river, rather
a sponge. And it's constantly changing.
Jerry Rigby, chair, Idaho Water Resources
Board: "There's basically four different
levels in this aquifer."
It spans 11,000 miles from Ashton on the
north to King Hill in the west and has 600
times the capacity of the American Falls
Reservoir.
Jerry Rigby, chair, Idaho Water Resources
Board: "This is an aquifer we are all sitting
on and we all need to understand it better."
The aquifer works like this - water intake,
called recharge, comes mostly from irrigation.
The other 40% comes from river and aquifer
infiltration and precipitation.
Jerry Rigby, chair, Idaho Water Resources
Board: "We've gone through a historical
drought. Because of that, when we get out of
that, assuming we do, optimistic we will, this
aquifer, which is a huge aquifer, will
replenish itself."
The discharge flows into the Snake River -
85%. The remaining percentage pumped for other
uses.
Jerry Rigby, chair, Idaho Water Resources
Board: "It's an accounting system, you only
get a reservoir to increase its level when
water's being put in."
That accounting is important because of the
debate - legal, political and commercial over
water availability.
Jerry Rigby, chair, Idaho Water Resources
Board: "It isn't as simple as saying, 'I have
a right in this aquifer.'"
Location, priority dates, and more. And
then there's the question of damage.
Jerry Rigby, chair, Idaho Water Resources
Board: "If we are mining the aquifer, then
obviously we need to get on top of it."
That's the charge from the legislature to
the Water Resources Board; set a plan to
maintain the health of Idaho's largest
aquifer.
A new Idaho water management plan is
expected to go before the legislature in
January.
