13 Years Of Experimental Grand Canyon Flows A Bust For ESA

[hatrack]

"A 13-year-old experiment aimed at improving ecological conditions in the Colorado River watershed below Glen Canyon Dam is failing and needs a management overhaul, according to a draft report by a group of scientists that monitors the dam's environmental effects. Since 1991, Glen Canyon Dam has operated under "modified low fluctuating flows" (MLFF), intended to help recover the endangered humpback chub and other species downstream in Grand Canyon National Park without scaling back power production or recreational activities such as rafting.

MLFF involves daily variations in flow. For example, on weekdays in July, daily fluctuations vary from 10,500 cubic feet per second (cfs) during the late evening and early morning off-peak hours to 18,500 cfs during peak times in the late afternoon and early evening. Still, the MLFF is a highly regulated version of the river's historic flows, which seasonally ranged from as little as 500 cfs to as much as 100,000 cfs.

Under the current flow regime, the endangered humpback chub, which once thrived throughout the Colorado River Basin but now occupies only the lower basin in the Little Colorado River, continues to spiral toward extinction, declining by an average of 14 percent each year, according to the draft report. "One of the justifications for the MLFF policy was apparently an assumption or prediction that MLFF would have beneficial ecological effects relative to the more violent diurnal flow variations that preceded it," the report says. "We show that no such beneficial effects are evident in the ecological system (except to abundance of exotic trout), and in fact the move to MLFF is correlated with a relatively sharp decline in humpback chub recruitment."

EDIT

In fact, the only beneficiaries of the modified low fluctuating flow regime have been exotic trout that eat endangered chub and the rafting industry, the report concludes. "At present, power utilities and their ratepayers are essentially subsidizing, at considerable cost, improvement in the quality of Grand Canyon for some recreational uses," the report reads. "It is one thing to impose such costs to deal with some broad public interest such as protecting an endangered species, but quite another one to impose it for the benefit of particular stakeholders." The issue of flows from the dam needs to be addressed "openly and quickly" before it "leads to a breakdown in the collaboration among stakeholders that has made adaptive management possible in Grand Canyon in the first place," the authors warn."

EDIT

http://www.livingrivers.net/archives/article.cfm?NewsID=605

[mike_c]

1. ESA?

Which ESA? I read the linked story and looked at the .pdf draft report but can't find a ref to the ESA.

[hatrack]

2. Sorry - it's not spelled out in the article

In the Grand Canyon, it's referring to the endangered chub species, which are now found only in short stretch of the Canyon just down from the Little Colorado.

[mike_c]

3. oh-- the Endangered Species Act....

Sorry, I was thinking that ESA referred to the oversight group. Context is everything....

[NNadir]

4. It may not be the most important environmental issue on the planet

but you really have me pissed off, Hatrack, about the damned Glen Canyon dam. I've always had a thing against dams, being a free river advocate, but a part of me has always bought in to the notion that they were somehow on some level acceptable or in some cases necessary. This really nasty case on which you report so well has really reopened the question in my mind.

If we can screw with the Grand Canyon what, if anything, is sacred?

[hatrack]

5. Could be worse - they wanted to build not 1, but 2 dams in the 1960s

IN Grand Canyon, as unbelievable as that sounds today. Had they been built, Havasu Canyon, Lava Falls, and all of Marble Canyon would have been flooded up to 500 feet deep, along with much else.

Had this abomination come true, it would have produced a net loss through evaporation to the river every year and accordingly cut downstream availability to Arizona, California and Mexico. Its only purpose was to generate even more hydropower so that BuRecs could finance even more dams elsewhere.

But seriously, check out "The Place No One Knew" by Eliot Porter and "Peaceful Canyon, Golden River" if you want to experience true piss-off regarding Glen Canyon.

[phantom power]

6. A professor showed a movie of Glen Canyon when I was in college

It made me cry. Which is a bit embarrassing when you're in the middle of a classroom.

How could anyone have looked at that canyon and thought nothing except "wow, that would make a great reservoir!"

[NNadir]

7. Have you ever given any thought to how much coal ash we could get

in that great big hole downstream from "Lake Powell"? If we could find appropriate fill for that hole, we could probably make a great high speed freeway from Las Vegas to Phoenix, and have room for lots of truckstops.

Not only that, but I note that people are killed from time to time falling into that hole, and others drown in the trickling stream that runs through it. We could save some lives and help the US solve its waste problem.

Why didn't we think of that earlier?

[phantom power]

8. There used to be a news-group called alt.pave.the.planet

They proposed a similar canyon-filling project, so as to allow them to more easily pave it over.

I could never quite figure out if they were serious. I chose to believe it was extra-dry ironic humor, so that I could get out of bed in the morning.