“Lake Powell: storage pond, silt trap, evaporation tank and garbage dispose-all, a 180-mile-long incipient sewage lagoon.”
― Edward Abbey, The Monkey Wrench Gang
If Lake Powell isn’t already doomed, it may soon be.
Insufficient runoff has put the reservoir on a quick and dangerous descent to 3,490 feet of elevation – a water level so low that Glen Canyon Dam’s hydropower turbines can no longer operate. A key part of the Western power grid would be lost.
The city of Page and the LeChee Chapter of the Navajo Nation also would lose their drinking water because the infrastructure that supplies them could no longer function.
Not to mention that if Powell falls to 3,490 feet, the only way millions of acre-feet of Colorado River water can flow past the dam and downstream to sustain Lake Mead – the reservoir on which Arizona relies – is through four bypass tubes, which have never handled that kind of volume, particularly for an extended period.
Engineers are concerned whether this setup can move enough water, especially if one or more of the tubes were damaged by heavy flows over time. If the bypass tubes move significantly less water than what the eight turbines do now, that could all but guarantee the demise of Lake Mead.
This is serious.
The U.S. Department of the Interior, which operates the two reservoirs via the Bureau of Reclamation, said in a grimly worded letter last week that it must take more drastic actions to slow Powell’s descent.
“We are approaching operating conditions for which we have only very limited actual operating experience – and which occurred nearly 60 years ago,” the letter states. “We hope to be able to delay or avoid operational conditions below (3,490 feet) but we fully realize that absent a change in the recent hydrological conditions, we may not be able to avoid such operations.”
Did you catch that? Interior is essentially saying that if we don’t get more snow (and that snow doesn’t produce more runoff), the best we may be able to do is delay the point at which Powell falls below 3,490 feet.
In other words, we are once again being asked to sacrifice – not to fix the problem, but simply to buy time.
If this feels like déjà vu, well, it is.
We haven’t even fully implemented the 500-plus plan from December, in which the lower basin states of Arizona, California and Nevada agreed to store an additional 500,000 acre-feet of water in Lake Mead each year, simply to lower the risk of it tanking before 2026.
That deal, which is only funded for the next two years but must persist through 2026 if we want to protect Lake Mead, essentially pays people not to use water. It’s not a solution. We’re simply buying time.
And that’s on top of the mandatory cuts in the Drought Contingency Plan, which the lower basin states signed in 2019 – again, not to fix Mead’s problems, but to simply buy us time.
Reclamation has already delayed the release of 350,000 acre-feet from Powell to Mead though the end of this month – a move that makes Powell appear about 7 feet higher than it otherwise would be. Its current elevation is 3,522 feet.
It also is finalizing a Drought Response Operations Plan to protect Powell elevations – something the upper basin agreed to do in its version of the Drought Contingency Plan – potentially by moving more water from the smaller reservoirs upstream into Powell.
When the reservoir is full, Glen Canyon Dam’s eight giant turbines have 1,300 megawatts of capacity, equivalent to a large coal power plant. The dam serves as a “baseload” power source, cranking out a steady stream of juice, which the federal Western Area Power Administration (WAPA) sells at below-market prices to Southwestern utilities, tribal nations and municipalities. It is also valuable as a “load-following” resource, meaning operators can ramp output up quickly to meet a spike in demand or a sudden loss of supply, contributing to grid resilience and helping to smooth fluctuations in wind and solar generation. Glen Canyon Dam was originally constructed primarily to store water during wet times and release it during dry periods. It also provides flood control, acts as a silt catchment basin for Lake Mead, and is a watercraft playground, drawing as many as 4.5 million visitors per year. But its role as a power source has risen to the top of its uses over the years.
Back in my geology classes they spend a lot of time on stream flows (where in geology terms, a stream refers to any size water flow from rivers down to blind creeks and whenever arroyos/wadis channel water). From my geology teachers’ perspective, the “job” of a stream is to take mountains and put them in the sea, and the “job” of a dam is to collect sediment and prevent it from moving to the sea.
Part of the regression of the Texas Gulf coast, for example, is due to the shoreline being starved of sediment from Texas’ dammed rivers used as reservoirs.