Audubon’s Jennifer Pitt, one of the most stubbornly optimistic actors in the Colorado River Basin, wrote this Friday:
[F]ederal officials project that within two years, the water level in Lake Powell could be so low that it would be impossible for water to flow through the dam’s turbine intakes. When that happens, it’s clear the dam will no longer generate hydropower, but it’s also possible the dam will not release any water at all. That’s because the only other way for water to move through the dam when the water is low is a series of outlet tubes that were not designed, and have never been tested, for long-term use.
What happens if little to no water can be released from Lake Powell? Water supply risks multiply for everyone who uses water downstream. That includes residents of big cities like Las Vegas, Phoenix and Los Angeles, and farmers and ranchers in Arizona, California and Mexico who grow the majority of our nation’s winter produce, as well as numerous Native American tribes. Some of these water users have alternative supplies, but some—including Las Vegas residents, Colorado River tribes and most farmers—do not. Day Zero for these water users might not happen immediately as Lake Mead, the reservoir fed by Lake Powell still has some water in it. But without flows from upstream to replenish it, Lake Mead would also be at risk of no longer being able to release water.
There is also the river itself. Think of it—no water flowing through the Grand Canyon. No water flowing in the Colorado River for hundreds of miles downstream from Hoover Dam. That’s an ecological disaster in the making for 400 bird species and a multitude of other wildlife, exceeding the 20th century devastation of the Colorado River Delta.
That implies the Upper Colorado flow into Lake Powell becomes zero. I’m not sure that has ever happened.
Presumably, if the outlet tubes won’t work, eventually inflows into Powell will creep up above the intake for the turbines. Still, not a pretty picture.
It’s time to stop pretending the CAP is an “assured water supply” under the general definition created by the 1980 Groundwater Management Act. (GMA DEFINES CAP as assured, but it fails the definition, otherwise)
This is the VERY LAST option the “powers/that-be” will choose, because their actual objective is to guarantee population growth for as long as possible. But it is the only option that will work.