Colson: Powell’s Puddle may soon be drained and gone
Are you tired of politics, deeply mortified by the rise of Donald Trump from the ashes of his own outsized ego and premature dementia, worried that the choice between The Donald and The Hillary is a devil’s bargain at best?
So I decided to leave behind the great political brouhaha this week and turn my mind to other matters.
I note with interest that the debate over the fate of Glen Canyon Dam — you know, the one that created Lake Powell in southern Utah, the second-largest artificial reservoir in the U.S., which has bedeviled environmentalists for decades — has reached the point where even the staid New York Times has hinted that the dam’s useful days are done.
Granted, the NYT story last weekend is not the first time anyone has dreamed of this outcome.
The environmental diaspora has been wondering for years about how long it would take before even the dam builders conceded that Glen Canyon Dam was a bad bet.
The late Edward Abbey’s most famous book, “The Monkeywrench Gang,” envisioned that the dam would one day burst or be blown up, and the river would be released to scour away the crumbling concrete.
Environmental warrior David Brower, founder of the Friends of the Earth, inadvertently helped create the lake and the dam when, in the 1950s, he fought to prevent construction of a different dam planned for Northwest Colorado and a compromise settlement lead to the building of Glen Canyon Dam.
Brower did that before he had seen Glen Canyon.
Once he saw Glen Canyon, with its immense system of natural arches and glorious side canyons, he immediately admitted that his ignorance had helped bring about a massive folly.
An article in The Guardian about a year ago dealt with the “disappearing” waters of the lake, noting that it took 200 million years for the Colorado River to carve out the gloriously breathtaking canyon country that was drowned by the rising waters of the lake starting in 1963, the year the dam was completed.
According to the May 22 NYT story — penned by a reporter working for the ProPublica news organization — there are a few reasons the idea of decommissioning Glen Canyon Dam is making waves, as it were.
One is that Lake Powell leaks.
That’s right, the waters of the lake have been leaking into faults and crevasses since the reservoir began filling, at a rate that some say has reached upward of 300,000 acre-feet per year. That translates to what some estimate as 120 billions of gallons of water annually that the engineers hoped would be used to generate power, the original reason for building the dam.
Another is the fact that the lake loses even more water, as much as 160 billions of gallons of water each year, to evaporation in the hot desert sun.
Yet another reason is an effect of global warming — or climate change, or whatever you want to call it — which has cut into the amount of water from snowmelt and other sources that feed the lake each year.
The net result is that the reservoir has been draining faster each year than it is being refilled, which has left Lake Powell looking more like Powell’s Puddle for some time.
Not only has this left an unsightly bathtub ring around the rim of the puddle — remnants of earlier high-water marks — it has slashed the amount of power generated by the dam’s huge turbines, to the point where the federal agency managing the power output of the dam spent $62 million in 2014 to buy power from other sources to meet the dam’s obligations.
One thing the article did not mention, in its litany of reasons Lake Powell might be drained, was the fact that the lake’s bottom has silted up over the years, further contributing to the puddle metaphor.
According to a 2011 article in High Country News, the river once carried 90 million tons of sand slurry through Glen Canyon. But these days, only about 15 million tons of silt is measurable downstream from the dam. The rest drops out of the flow and settles to the bottom — 75 million tons of sludge building up every year over the course of the past half-century.
They say the muck is about to reach the dam’s lowermost outlet, some 237 feet above the base of the dam, which would signal the end of the dam’s useful life.
According to the NYT article, Glen Canyon Dam would not be dismantled. Rather, the flood gates would be opened and the lake would drain away, presumably with its load of silt.
The water would then travel down the Colorado River to Hoover Dam, where it would help fill Lake Mead, which also has seen its water levels dropping. Because Mead is believed to be “water tight” (no major leaks) some say that sending the river to Mead would lessen the annual losses by perhaps a couple of hundred thousand acre-feet a year.
Makes sense to me.
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