NB: The item below is lengthy, but worth reading. Unfortunately, with
the various anthropogenic global warming international governmental
meetings accomplishing nothing to really reduce not just new emissions
of greenhouse gases but to reduce the current atmospheric greenhouse gas
concentration, and given historical realities of pre-industrial
semi-arid regions of the USA, the scenarios described below are highly
probable. (The various governments around the world with respect to
fossil fuel use and deforestation are largely controlled by the fossil
fuel industries and the demand for profiteering, including the demands
for nations such as the PRC to repeat the energy sources path of the
industrial revolution through the 20th Century.)
https://www.yahoo.com/news/officials-fear-complete-doomsday-scenario-202316932.html
Washington Post
Officials fear 'complete doomsday scenario' for drought-stricken
Colorado River
Joshua Partlow, (c) 2022, The Washington Post
Thu, December 1, 2022 at 12:23 PM
PAGE, Ariz. - The first sign of serious trouble for the drought-stricken
American Southwest could be a whirlpool.
It could happen if the surface of Lake Powell, a man-made reservoir
along the Colorado River that's already a quarter of its former size,
drops another 38 feet down the concrete face of the 710-foot Glen Canyon
Dam here. At that point, the surface would be approaching the tops of
eight underwater openings that allow river water to pass through the
hydroelectric dam.
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The normally placid Lake Powell, the nation's second-largest reservoir,
could suddenly transform into something resembling a funnel, with water
circling the openings, the dam's operators say.
If that happens, the massive turbines that generate electricity for 4.5
million people would have to shut down - after nearly 60 years of use -
or risk destruction from air bubbles. The only outlet for Colorado River
water from the dam would then be a set of smaller, deeper and rarely
used bypass tubes with a far more limited ability to pass water
downstream to the Grand Canyon and the cities and farms in Arizona,
Nevada and California.
Such an outcome - known as a "minimum power pool" - was once
unfathomable here. Now, the federal government projects that day could
come as soon as July.
Worse, officials warn, is the possibility of an even more catastrophic
event. That is if the water level falls all the way to the lowest holes,
so only small amounts could pass through the dam. Such a scenario -
called "dead pool" - would transform Glen Canyon Dam from something that
regulates an artery of national importance into a hulking concrete plug
corking the Colorado River.
Anxiety about such outcomes has worsened this year as a long-running
drought has intensified in the Southwest. Reservoirs and groundwater
supplies across the region have fallen dramatically, and states and
cities have faced restrictions on water use amid dwindling supplies. The
Colorado River, which serves roughly 1 in 10 Americans, is the region's
most important waterway.
The 1,450-mile river starts in the Colorado Rockies and ends in the Sea
of Cortez in Mexico. There are more than a dozen dams along the river,
creating major reservoirs such as Lake Powell and Lake Mead.
On the way to such dire outcomes at Lake Powell - which federal
officials have begun both planning for and working aggressively to avoid
- scientists and dam operators say water temperatures in the Grand
Canyon would hit a roller coaster, going frigid overnight and then
heating up again, throwing the iconic ecosystem into turmoil. Lake
Powell's surface has already fallen 170 feet.
Lucrative industries that attract visitors from around the world - the
rainbow trout fishery above Lees Ferry, rafting trips through the Grand
Canyon - would be threatened. And eventually the only water escaping to
the Colorado River basin's southern states and Mexico could be what
flows into Lake Powell from the north and sloshes over the lip of the
dam's lowest holes.
"A complete doomsday scenario," said Bob Martin, deputy power manager at
Glen Canyon Dam, as he peered down at the shimmering blue of Lake Powell
from the rim of the dam.
- - -
'A catastrophe for the entire system'
In August, the Bureau of Reclamation announced it would support studies
to find out if physical modifications could be made to Glen Canyon Dam
to allow water to be released below critical elevations, including dead
pool. That implies studying such costly and time-consuming construction
projects as drilling tunnels through the Navajo sandstone at river
level, said Jack Schmidt, a Colorado River expert at Utah State University.
"There was a time in my professional career that if anybody from
Reclamation ever said that, they'd be fired on the spot," said Schmidt,
who served as the chief of the U.S. Geological Survey's Grand Canyon
Monitoring and Research Center during the Obama administration. Even
raising that issue is "a huge sea change telling you how different the
world is."
This year, the Biden administration called on the seven states of the
Colorado River basin to cut water consumption by 2 to 4 million
acre-feet - up to a third of the river's annual average flow - to
protect power generation and avoid such dire outcomes. But negotiations
have not produced an agreement. And the Interior Department has not yet
mandated those cuts, despite missing its own August deadline to reach an
agreement.
But these types of ominous scenarios are starting to be considered. With
Lake Powell at one-quarter full, Reclamation has begun a feasibility
study on the prospect of harnessing the deeper bypass tubes for power
generation. The entity that markets Glen Canyon's electricity - the
Western Area Power Administration, known as WAPA and part of the Energy
Department - is working with two national laboratories to assess what
electricity would be available for purchase if Glen Canyon shut down.
And construction is also underway on a project to install deeper pipes
to protect the city of Page, Ariz., and its 7,000 residents, from losing
its supply of drinking water.
The chances of hitting minimum power pool (lake elevation 3,490 feet
above sea level) within the next two years is part of Reclamation's
minimum probable forecast, and more likely scenarios have water levels
staying above that threshold. But researchers including Schmidt have
documented how Reclamation's projections have been too optimistic in
recent years amid the warming climate and historic drought that is
wringing water out of the West on a grand scale.
"The critical part about what's been happening and what climate change
is forcing us to do is: We have to look more at the extremes," said Tom
Buschatzke, director of Arizona's Department of Water Resources, said in
an interview. "We've got to plan for the low end."
Reclamation said in a statement it now relies on a more recent 30-year
climatology window - 1991 to 2020 - to make forecasts, which leaves out
the wet years of the 1980s and incorporates more drought, which "will
improve accuracy and remove some biases."
Buschatzke has also been raising the alarm about Lake Powell reaching
dead pool - an elevation 120 feet below the threshold for producing power.
"It is a possibility. I can't tell you the probability," he said. "But
that's an outcome that would be not only an ecological disaster, but the
world would have its attention on such an outcome in a very negative way."
If that happens, "you're not going to have a river," he added. "It would
be a catastrophe for the entire system."
- - -
'Huge problems for the Grand Canyon'
In the 23rd year of the Western drought, Lake Powell's once crowded boat
ramps end in sand. Dirt bikes roar across newly exposed shores.
Exquisite arches and rock formations, lost when the reservoir filled in
the 1960s, are re-emerging.
As the water has receded, so has the ability to produce power at Glen
Canyon, as less pressure from the lake pushes the turbines. The dam
already generates about 40 percent less power than what has been
committed to customers, which includes dozens of Native American tribes,
nonprofit rural electric cooperatives, military bases, and small cities
and towns across several southwestern states. These customers would be
responsible for buying power on the open market in the event Glen Canyon
could not generate, potentially driving up rates dramatically.
The standard rate paid for Glen Canyon's low-cost power is $30 per
megawatt hour. On the open market, these customers last summer faced
prices as high as $1,000 per megawatt hour, said Leslie James, executive
director of the Colorado River Energy Distributors Association.
"That will be very financially damaging," said Bryan Hill, the utility
manager for Page, one of the cities that relies on the dam's low-cost
hydropower for one-third to half of its electricity needs. "Huge, for
everybody. For businesses. For single moms. It will be a financial
hardship."
Glen Canyon's electricity is important for the nation in other ways. The
dam is what's known as a "black start" facility for the country's
largest nuclear plant, the Palo Verde Generating Station in Arizona.
This means the dam could bring the nuclear plant back online if it shut
down and needed to restart.
In September, Glen Canyon sent about 80 megawatts of power to California
for three hours at the height of its record-breaking heat wave, helping
the state narrowly avoid rolling blackouts. It was the second time in
the past few years that the dam has been called on to ramp up during
emergencies threatening the electric grid, said Adam Arellano, an
executive with the Western Area Power Administration.
"Those emergencies would probably happen more frequently without Glen
Canyon Dam just because there's such a small margin of available
electricity during those really hot days," he said. "That's a very big
thing."
When Martin began working at Glen Canyon eight years ago, the drought
had already taken a toll on the lake, but he never envisioned a day when
the turbines might stop spinning.
"Everybody that works here, your focus, your mission, is to keep these
units either running or keep them available to run," he said. "So if you
came into a powerhouse and it was quiet, that would kind of go against
everything you've dedicated your career to."
Being forced to switch to the four smaller bypass tubes would instantly
cut the dam's capacity to release water by two-thirds. If water levels
and pressure fell further, these pipes would quickly lose the ability to
deliver the millions of acre-feet of water the lower basin states
consume each year, the Glen Canyon Institute wrote in a report in August
on low water scenarios.
"That dam is just not capable of delivering water at lower levels. It's
going to create huge problems for the Grand Canyon," said Eric Balken,
the institute's executive director.
Martin and others are now planning ways to stay productive if lake
levels reach power pool, even temporarily. They expect a surge in
maintenance projects - far easier to complete when turbines aren't
spinning - and are lining up materials for the jobs. He compared it to a
farmer in winter, whose work doesn't stop.
"What would have been a maintenance nightmare to coordinate, now the
equipment is off and you can dive right in there and get all kinds of
work done," he said. "So kind of, we're making lemonade with the lemons,
I guess."
- - -
A disrupted ecosystem
Julie Fleuridas rested on a red rock in Waterholes Canyon, her face
flushed in the afternoon sun. For six hours, the 56-year-old Trader
Joe's employee and her friends had been paddleboarding down the Colorado
River - from Glen Canyon Dam down to Lees Ferry, a 16-mile stretch
popular with kayakers, fishermen and flotillas of paddleboarders.
"How far to Lees Ferry from here?" she asked Ted Kennedy, a U.S.
Geological Survey research ecologist who was passing by.
"If you stay in the current, it will be less than an hour," he said.
"Last time I did this, like six years ago, it was much quicker," she
said. "It's just the water level is so low that the water is just not
running fast. So it's a lot of paddling."
There are few people more intimately aware of those flows - and their
impact on the web of fish and insect life through the Grand Canyon -
than Kennedy. Since 2002, he has worked at the Grand Canyon Monitoring
and Research Center in Flagstaff, Ariz., and he has watched this stretch
of river throughout this historic drought.
With Lake Powell so diminished, water temperatures have risen
dramatically - from the high 40s when he started, to a record high of
near 70 degrees this summer - as water closer to the surface is now
passing through the dam. Swimming, once for the hardiest, is now
commonplace.
The habitat for fish has also transformed. Warming waters have helped
recover populations of the humpback chub in the Grand Canyon - a species
reclassified from endangered to threatened last year - as it became warm
enough to spawn. But the fate of these and other native fish are now
confronting fresh threats: the smallmouth bass, a voracious predator.
"This is basically the start of an invasion of a new species," Kennedy said.
Dozens of these bass, including juveniles, have been caught this year in
the first 15 miles below Lake Powell - as more of the surface swimmers
get sucked through the turbines - prompting an aggressive effort to
assess their numbers and block them from the Grand Canyon.
"I believe the smallmouth bass presents a clear and present danger to
the humpback chub and other threatened native fish in the Grand Canyon,"
Ed Keable, superintendent of Grand Canyon National Park, said in an
interview. The record-high temperatures "could allow smallmouth bass to
reproduce within the entire river system for the first time."
The federal government has begun fighting back on several fronts - from
poisoning tributaries to shocking the water with electricity. Some
fishing guides worry these methods to eliminate bass will be both futile
at stopping the predator and harmful to another important industry: the
renowned rainbow trout fishery and the lodges that service it.
Water temperatures have already risen so high - and dissolved oxygen
levels fallen so low - as to start harming the trout, according to
fishermen and scientists. Dave Foster, a former USGS scientist who has
been guiding fishermen for more than three decades, has turned away
clients this year after catching weakened trout he can't revive. He
worries an expanded electro-fishing effort will be another major blow.
"There will be a negative impact on the trout population," he said.
"It's really pretty disconcerting to me."
The trout and the threatened chub could get a reprieve, at least
temporarily, if lake levels continue to fall. If the dam drops below
power pool, and switches to the deeper bypass tubes, water temperatures
in the Grand Canyon would suddenly drop by as much as 15 degrees. This
could limit the ability of smallmouth bass to reproduce.
"Going below power pool, initially, could be a good thing if your
biggest concern is smallmouth bass," Kennedy said. "But then if you get
lower and lower, closer to the dead pool, you get back to that zone
where both of those bad things are happening: You're going to have water
temperatures in the river that are conducive to their spawning and
you're going to be passing large numbers of them through."
- - -
'Less like a river, and more like an irrigation ditch'
Arguments against Lake Powell have been around as long as the lake. Its
existence, to some, amounts to an ecological atrocity, the drowning of
miles of intricate slick rock canyons. Some argue it is unnecessary for
water storage, power generation or the tourist economy - despite having
more than 3 million visitors last year.
"Everybody keeps running around saying how can we prevent this from
happening," said Dan Beard, who served as the Bureau of Reclamation's
commissioner from 1993 to 1995. He added that he wouldn't be surprised
to see dead pool in the next three years. "My question is: Why should we
prevent it from happening?"
But the federal government has already taken unprecedented steps to
protect Lake Powell from dropping to dangerous levels.
In May, Reclamation reduced the amount of water it planned to release
from the dam from 7.48 million acre-feet to a record low 7 million, the
first such midyear cut. It moved another 500,000 acre-feet into Lake
Powell from an upstream reservoir. The ongoing negotiations to cut more
Colorado River use, if successful, could significantly improve
conditions for Lake Powell and Lake Mead, located in Nevada and Arizona.
In late October, the Interior Department signaled it may take further
unilateral action by announcing it could revise the guidelines - set in
2007 and revised in 2019 - that regulate water use from Lake Powell and
Lake Mead. Interior Secretary Deb Haaland said the administration is
"committed to taking prompt and decisive action necessary to protect the
Colorado River System and all those who depend on it."
Some say the gravity of the threat is enough to spur the states and
federal government to make the necessary cuts in water use.
"I'm actually very optimistic that we're not going to go below power
pool," said Arellano, the WAPA executive. "This is the number one issue
for pretty much everybody in the hydropower industry."
But the reservoirs remain vulnerable. The most recent five-year
hydrology projection estimates the chance at reaching minimum power pool
(elev. 3,490) at 10 percent next year and 30 percent in 2024, as dry La
Niña conditions are expected to continue. Reclamation predicts there is
zero chance of reaching dead pool (elev. 3,370) at Lake Powell over the
next five years.
"If there was a line in Vegas, and I was a betting man, I think I'd
probably bet we'll go below 3,490," said Charles Yackulic, a research
statistician with USGS who is part of a team that was tasked in August
to study how power pool or dead pool would impact the Colorado River.
Below that threshold, as Glen Canyon dam is able to release less and
less water - the change between how much water is flowing at night or
during the day would also diminish. That would lessen the "tides" that
now characterize life in the Grand Canyon, water flows that fluctuate
based on demand for hydropower.
Ultimately, the Colorado River would "become less like a river,"
Yackulic said, "and more like an irrigation ditch."