Dear HCN,
We read with great
interest and a sense of déja` vu Steve Stuebner’s article on
the Big Lost River being dewatered due to groundwater pumping (HCN,
2/20/95).
Déja` vu because here in Nevada
we are dealing with the imminent collapse of a desert lake
ecosystem, and groundwater pumping for agriculture is playing an
important role in this basin’s problems.
Walker
Lake is located in sparsely populated Mineral County in
west-central Nevada. Mineral County’s economy is tied to the lake
with many dollars coming from fishermen, boaters and RV’ers. The
lake is startling when first viewed, as are all desert lakes: a
vast blue gem, five miles wide and 14 miles long, with the steep
cliffs of the Wassuk Range seeming to rise right out of the water
to the west. Even more startling is that the lake supports what was
until recently a trophy Lahontan cutthroat trout fishery. It is an
“endangered species of lake” according to Alex Horne, a University
of California limnologist, one of only a handful of deep desert
lakes supporting salmonid fishes in the
world.
But all of this appears not enough to save
Walker Lake’s fishery from collapse in the next few years. The
lake’s problems are deceptively simple: It is a terminal lake, the
final destination of waters from the Walker River. But little or no
water ever reaches it.
Upstream are vast fields
of alfalfa, pasture and other crops farmed in Bridgeport, Antelope,
Smith, and Mason valleys and on the Walker River Paiute
Reservation. They explain the empty sand channel leading to the
lake because irrigators use all the water in the system – an
average of 250,000 to 300,000 acre-feet per year – and there are
plenty of water rights beyond what the system yields in any given
year. The overallocation of the river system, completely legal and
governed by an adjudicated federal court decree, leaves no water
for the lake.
Added to this is groundwater
pumping which supplements river diversions for agriculture. Over
the past eight years of drought, the aquifer has been drawn down as
much as 45 feet in one valley and 85 feet in another. The small
amount of river water that isn’t diverted then flows underground to
fill this deficit. Hydrological studies indicate that 700,000
acre-feet of water have been lost to the river during drought years
to recharge the over-pumped aquifer.
After about
100 years of surface overallocation and 30 years of groundwater
pumping, Walker Lake is now at the brink of losing a fishery that
in past years rewarded fishermen with 30-pound trout. As volume
decreases, total dissolved solids increase to the extent that trout
and the food chain upon which they depend will soon be unable to
survive. In addition, migratory birds – loons, pelicans, ibis,
plovers, curlews and many others – will lose a critical food and
rest stop during their long migrations through the arid Great
Basin.
What we are seeing in the Walker River and
Snake River basins and elsewhere in the West is a failure to
recognize that, in many instances, surface and groundwater
resources are the same resource. We need to recognize that
groundwater pumping in near-river aquifers is a surface diversion
of future flow that is detrimental to surface water irrigators and
the environment. We need cooperation from water users and water
managers at all levels – local, state and federal – to resolve
these complex Western water issues.
Unless we
start managing rivers and groundwater together and accepting the
fact that actions taken on one eventually impact the other, more
Walker Lake and Big Lost River scenarios will come to
pass.
Ann Kersten, Susan Lynn,
Tom Myers
Reno,
Nevada
Susan Lynn is executive
director and Ann Kersten research coordinator at Public Resource
Associates. Tom Myers is a graduate student in hydrology at the
University of Nevada,
Reno.
This article appeared in the print edition of the magazine with the headline The result of groundwater pumping is obvious in Nevada, too.
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