Tag: Lake Mead

NPR’s interview with Colorado River author misses an important angle: The effort to save Lake Mead

On By azwater

Where the Water Goes by David Owen

National Public Radio has some of the best interviewing talent in American journalism, and there’s none better than Terry Gross, whose Peabody Award-winning weekday program, “Fresh Air,” has consistently delivered provocative and fascinating interview sessions. On radio, there’s really none better.

But, let’s face it Westerners, the perspective of much of NPR’s programming is often East Coast-centric. Gross’s interview on Thursday with the author of a new book on the Colorado River is further evidence that if they don’t know about it in New York… well, it just isn’t.

Where the Water Goes: Life and Death Along the Colorado River (Penguin Group USA) by David Owen by and large is an honest and fair assessment of the challenges facing the Colorado River today — a source of water for over 35 million people living in the American Southwest. Especially in the face of long-term, chronic drought, those challenges have been daunting. Owen chronicles most of them in Where the Water Goes, including the tender status of Lake Mead, the largest reservoir on the Colorado River system, which today is less than 40 percent full.

In his NPR interview with Gross, Owen explained the 1922 agreement among the federal government and the Colorado River states to apportion shares of the river’s water. The long-standing agreement, as it has turned out, is one of the biggest reasons why Lake Mead is in danger of descending now to “deadpool” level, the critical point at which water may no longer flow out of the lake. Said Owen:

“It’s one of these great sort of ironies of history that in the 19 – the 1920s were some of the wettest years in that part of the country since the 1400s. So the river at that time was carrying more water than ever. And so when the states divided up the river, they were dividing up – actually water that didn’t exist. On the other side, the good side is that, well, it’s almost a century later and that compact, the agreement among those states, still exists.”

Owen’s assessment is pretty much spot on… as far as it goes. But what he leaves out in his interview with Gross is some vital perspective: Fixing that structural deficit created in 1922 is the consuming issue facing Colorado River water managers today.

It’s not like they’re all slapping their foreheads, going, “Oh, that’s why we’re in this mess!”

Addressing the structural deficit is one of the highest priorities of the “Drought Contingency Plan,” or DCP, that the river states and the federal government have been negotiating for nearly three years. See: here, here, here, here, here, here, here, here, here and…(whew!) here.

We appreciate Owen and Terry Gross educating NPR’s mostly waterlogged, mostly Eastern audience about the challenges facing the much more arid West. Just because California and much of the West has gotten drenched of late doesn’t mean pursuing a DCP is any less of a priority.

There really is another important chapter to that story about where the water goes. It’s about the effort to keep a lot of it in Lake Mead.

 

 

“Fill Mead First” plan to drain Lake Powell has sprung some big leaks, a new assessment finds

On By azwater

Utah State University analysis of proposal finds water savings would be slight and ecological hazards plentiful

lake-mead-viewed-from-arizona

Whether we are talking about draining all of its water or just most of it, reducing  Lake Powell to a secondary status behind Lake Mead would fail in two of the plan’s most important goals, according to a technical assessment released last fall by Utah State University researchers.

One of the primary conclusions of the so-called “Fill Mead First” proposal was that water loss, through evaporation and through reservoir bank storage and seepage into the bedrock below Lake Powell, would be greatly diminished by storing water primarily in Lake Mead.

“Fill Mead First” was developed by the Glen Canyon Institute of Salt Lake City, and enjoys strong backing from environmental groups advocating that the Glen Canyon Dam be decommissioned.

The Utah State assessment, however, found that estimates of water saved from evaporation by effectively combining the two great Colorado River reservoirs were too inaccurate – and data too old – to use them for rendering a sound scientific judgment.

The analysis led by Jack Schmidt, director of Utah State’s Center for Colorado River Studies, found considerable “state of the science” data regarding evaporation at Lake Mead. The work had been performed by the U.S. Geological Survey.

But at Powell, no such research has been conducted since the mid-1970s. What’s more, the USU assessment learned that no studies of water seeping into the relatively porous Navajo sandstone bedrock of Lake Powell had been conducted since the mid-1980s.

Conducting their own research, the Utah State analysts concluded while there may be a slight decrease in evaporation loss by combining the two reservoirs in Lake Mead, the uncertainty of those conclusions appeared too high to base such a huge infrastructure choice – draining Lake Powell – on them.

The Fill Mead First study assumed that reservoir bank storage would remain constant for their analysis period.  The Utah State researchers, however, estimated the bank storage rates have decreased since Lake Powell was completed and therefore the savings would not be significant.  Water in bank storage can return to the reservoir as its elevation drops.

Seepage losses into the Lake Powell bedrock, meanwhile, likely are ten percent of what Fill Mead First advocates claim.  The USU study noted that some of the seepage water returns to the Colorado River above Lee’s Ferry.

Schmidt told Phys.org science-news magazine that it would be best to wait for a better system of data collection and analysis before making any major decisions about the future of Lake Powell.

“The Fill Mead First plan has encouraged us to think broadly about how and where we store water in the Colorado River system,” said Schmidt.

“But the magnitude of potential ecosystem changes caused by the FMF plan are so great and the water savings are so uncertain that implementation should await a new program of data collection and analysis designed to reduce uncertainty about the key process of evaporation and bank seepage.”

Utah State’s findings regarding the ecological consequences of lowering or draining Lake Powell appear even more significant than uncertainty about water losses.

The Fill Mead First proposal would have little effect in its initial phases on the amount of fine-grain sediment released into the Colorado River below Glen Canyon Dam. The plan’s final phase, on the other hand, would “cause significant ecosystem adjustments associated with the sudden change from relatively clear water to a very turbid river.”

The assessment concluded that unless Glen Canyon Dam was bypassed completely, it would be impossible to provide the supply of sand needed to reconstitute the eddy sandbars and camping beaches that today are an important part of the river’s ecosystem throughout the Grand Canyon.

The assessment found that impacts to the river’s aquatic and riparian ecosystem – including the existing population of endangered native species such as the humpback chub – could be “potentially significant.”

Editor’s note: Arizona Water News published a two-part series that began September 29 arguing that the effort to decommission Glen Canyon Dam was ill-advised. That series can be found here. And here.