Power Plant Operations Tied to Water Challenged by Changes in
10 September 2012
By Juliet Eilperin
BOULDER CITY, Nev. -- Drought and rising temperatures are forcing
water managers across the country to scramble for ways to produce
the same amount of power from the hydroelectric grid with less
water, including from behemoths such as the Hoover Dam.
Hydropower is not the only part of the nation's energy system that
appears increasingly vulnerable to the impact of climate change,
as low water levels affect coal-fired and nuclear power plants'
operations and impede the passage of coal barges along the
"We're trying to manage a changing climate, its impact on water
supplies and our ability to generate power, all at once," said
Michael Connor, commissioner of the Bureau of Reclamation, the
Interior Department's water-management agency. Producing
electricity accounts for at least 40 percent of water use in the
Warmer and drier summers mean less water is available to cool
nuclear and fossil-fuel power plants. The Millstone nuclear plant
in Waterford, Conn., had to shut down one of its reactors in
mid-August because the water it drew from the Long Island Sound
was too warm to cool critical equipment outside the core. A
twin-unit nuclear plant in Braidwood, Ill., needed to get special
permission to continue operating this summer because the
temperature in its cooling-water pond rose to 102 degrees, four
degrees above its normal limit. Another Midwestern plant stopped
operating temporarily because its water-intake pipes ended up on
dry ground because of the prolonged drought.
Scott Burnell, a spokesman for the Nuclear Regulatory Commission,
said the safety of America's nuclear plants "is not in jeopardy,"
because the sources of water cooling the core are self-contained
and might have to shut down in some instances if water is either
too warm or unavailable. "If water levels dropped to the point
where you can't draw water into the condenser, you'd have to shut
down the plant," he said.
The commission's new chairman, Allison Macfarlane, has asked her
staff to look at "a broad array of natural events that could
affect nuclear plant operations" in the future, such as climate
change, Mr. Burnell added.
For more than three-quarters of a century, the Hoover Dam has
represented an engineering triumph, harnessing the power of the
mighty Colorado River to generate electricity for customers in not
just nearby Las Vegas but as far away as Southern California and
But the bleached volcanic rock ringing Black Canyon above Lake
Mead, the reservoir created by the dam, speak to the limits of
human engineering. Higher temperatures and less snowpack have
reduced the river's flow and left the reservoir 103 feet below
elevation for its full targeted storage capacity, which it last
came close to reaching in 1999.
In the Colorado River's 100-year recorded history, 1999 to 2010
ranks as the second-driest 12-year period, yielding an average of
16 percent less energy.
Scientists have just begun to study some key questions, such as
the rate of evaporation off dams' storage facilities. Predicting
river flows -- which can flood one year and dry up the next -- is
"Because of the variability of river systems, it's a lot more
difficult in modeling how climate change will affect them," said
Jenny Kehl, who directs the Center for Water Policy at the
University of Wisconsin at Madison's School of Freshwater
In Nevada, water managers are adjusting to what they call "the new
Since 2003, Patricia Mulroy, who oversees the operations of the
Southern Nevada Water Authority, has imposed watering restrictions
on golf courses and homeowners and increased water reuse from golf
courses while also instituting an incentive program that to date
has paid residents $200 million to pull out turf and replace it
with water-efficient vegetation. Enough turf has been ripped out
to lay a stripe of sod stretching three-fourths of the way across
the planet; overall, she has reduced total water use by a third in
10 years. She has raised water rates four times in less than a
decade while activating long-held water rights in east-central
Nevada in 2004 to ensure that the community is less dependent on
the Colorado River.
While some experts have suggested more ambitious measures, such as
curtailing growth, making it harder for farmers to get cheap water
and removing some dams to allow the Colorado River to regain some
of its natural flow, federal, state and local authorities have
resisted such proposals.