A dry future for Lake Powell?
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Is Lake Powell going dry? The idea generates fierce debate. Although Lake Powell and Nevada's Lake Mead -- the West's largest reservoirs of water -- are half-full due to a long drought in the American Southwest, Western water officials maintain that the two reservoirs will not be allowed to dry up. In December, seven Western states and the Department of the Interior agreed to take measures to keep water flowing in the area.
For Utah, Lake Powell of course is very important. The critical debate as populations grow is water sustainability. Without water, we can't live, livestock can't live and crops can't grow. And we need those reservoirs to generate much-needed hydropower.
A just-released study by the San Diego Scripps Institute of Oceanography has roiled the waters considerably. It predicts a 50 percent chance that both Lake Powell and Lake Mead will be dry by 2021.
The study opines there's a 10 percent chance that by 2013, there will be no more usable water in Powell or Mead. Its researchers believe that by 2017, there's a 50 percent chance the lakes could no longer generate hydropower.
If true, that's catastrophic.
As we mentioned, the Lake-Powell-is-going-dry hypothesis meets fierce resistance. Larry Dozier, deputy general manager at the Central Arizona Project, told The Associated Press the Scripps study was "absurd," and used the term "outrageous assumptions."
Maybe there's some truth to that. Global-warming projections at times have been exaggerated.
Nevertheless, the Scripps study is not pop science. These are well-regarded scientists, and we need to respect their arguments. Also, whether Lake Powell dries up in 13 years or 113 years, we are in a drought, our communities are growing, and we must find effective ways for sustainable living in a drought-stricken area.
We are facing a future of living with far less water than we have in the past. Water rights, global-warming initiatives, water consumption and how to adapt are all crucial questions to be answered. Agriculture still takes the lion's share of our reservoirs' waters. How do we change those allocations without hurting people, industries, crops and livestock?
These are all very important issues our leaders must deal with now. Time may be running out.
Reader Comments
According to a report from the Scripps Institution of Oceanography [UC San Diego], http://scrippsnews.ucsd.edu/Releases/?releaseID=876 , Lake Mead and Lake Powell could be dry by 2021. Specifically, the report indicates that there is a 10% chance of that occurrence. That would imply that a 90% chance exists that it will not occur. But, risk assessment aside, one must consider the sources of the opinion, which Tim Barnett and David Pierce of the Institution claim are three-fold: increased human demand, evaporation and human-induced climate change.
The first two are solid contributors, however, both do not conclude, as one may be led to believe, that the consumed water by those downstream from the reservoirs will not be recycled. According to NASA, the volume of water in all its forms: liquid, solid and gas, is a finite and stable quantity on earth, shifting between the three based upon climate change, but the net volume of water does not change. [The total earth water volume is reported by NASA to be 1.39 x 109 cubic kilometers – NASA Earth Observatory, Graham, S, “The Water Cycle.”] The fact is, our consumed water is recycled [I know you don’t like to think about that!], though, granted, the re-distribution may not all end up in Mead and Powell.
But there is that troubling third contributor, which, try as we might, is not fact but merely theory, and the theory is underpinned by an instable foundation. Consider the claims by former Vice-President Al Gore in his popular slide show presentation, “An Inconvenient Truth,” in which a sampling from his own demonstration is revealing: Mr. Gore spent considerable time with a satellite patchwork image of the globe – edited to remove all clouds. Dramatic, perhaps, but if you bought into the demonstration, you also bought into the hype when the fact is, clouds represent a significant contribution to climate change, and we are mostly ignorant of how they function. For example, what are the absolutes known with regard to cloud formation, density, reflectivity and precipitation rate? The answer: we’re not sure. We have gained little understanding of one of the most basic contributors to climate change, yet Mr. Gore spent considerable time to remove them from the conversation. Climate change does occur, but until the science can be more exacting, making claims that reservoirs will be dry in thirteen years is a bit dramatic, and not very accurate. Somewhere between 10% and 90% is the likely truth of the risk.
How do the affects of Lake Chad in Africa compare to Lake Powell? Lake Chad in Africa decreased in size from 4,000 sq miles down to only 839 square miles during the dry season. This decrease happened in only 20 years. Since it was substantially larger than Powell is it not possible that Lake Powell and Lake Mead dry up in half that time?