You might want to read Part 1 before this post.
Although it deals with water shortage, James Powell's Dead Pool opens with a tale of too much water.
It is late spring 1983, and after a monstrous El Niño winter, U.S. Bureau of Reclamation engineers are struggling to keep Glen Canyon Dam from becoming just part of the sediment load down the Grand Canyon. The dam comes close to failing, closer than Reclamation would publicly admit, but it manages to hold back the snowmelt coursing down the Colorado River's mainstem and tributaries.
Years after that event, a Reclamation hydrologist was unusually candid with some of us. "We came that close," he said, holding his thumb and index finger about a half-inch apart. I remember wishing that one of my engineer friends, who would always wax enthusiastically about routing dam-break floods, could have been there to hear this guy's description of what they did to stave off the disaster that would have occurred had the dam failed - would you believe a 580-foot high flood wave initially forming after Glen Canyon Dam went out, tearing down the Grand Canyon at 25 miles per hour, then attenuated to a 70-foot high wave taking out Hoover Dam and the remaining Colorado River dams in succession, just like so many dominoes? One wag noted that Mexico would have received more than its Colorado River allotment that year!
As an aside, I remember that winter well. I was living in the Sierra Nevada just outside the hamlet of Truckee, CA. I earned my stripes shoveling snow and maneuvering either our Honda Civic station wagon or VW Rabbit on a daily 60-mile round trip commute to Reno, where both my wife and I worked. We both appreciated CalTrans for keeping Interstate 80 open. That winter I well understood the utility of A-frame houses with metal rooftops. If only we'd had one!
After that introductory scene and some excellent historical background (John Wesley Powell et al.), Powell proceeds to detail the work of the "Concrete Pyramid" - Reclamation and the U.S. Army Corps of Engineers; pork-barrel Western politicians; mega-construction companies; and agribusiness, fed to steroid-size through subsidies (Powell uses the pejorative term "welfare") - in reshaping the American West.
"Cash-register" dams and "river basin accounting" are exposed as tricks to build more projects, even when the numbers didn't add up. You can have umpteen unnecessary projects in a basin, each with a lousy benefit-cost ratio, but if you have one "cash-register" dam project to pay for all the others, then the whole thing's a go. Reclamation and the Corps were way ahead of the rest of us - they were taking holistic (river basin-wide) views!
Powell notes that agriculture uses a lot of water - he does not necessarily see a great problem with that, but does question why we insist on growing crops like cotton and alfalfa in the desert with irrigation, or try to irrigate high-elevation areas with short growing seasons. At least cotton is a high-value crop, unlike alfalfa, which is essentially grown to feed livestock.
Although Reclamation and the Corps would butt heads at some places in the West, the Colorado River Basin was Reclamation's domain, or more accurately, Reclamation's river. The Colorado River flows through some of the driest, and, in my opinion, the most spectacular, parts of the USA. Its watershed comprises about 250,000 square miles (650,000 square kilometers), but its annual flow is relatively puny: 15 MAF (million acre-feet), probably at least 0.4 MAF too high, or about 590 cubic meters per second (cms). I live along the banks of the Willamette River, whose mainstem length is barely 180 miles and whose drainage basin of about 12,000 square miles (31,000 square km), 5% of the Colorado's, produces an average annual discharge of about 24 MAF (940 cms), 60% greater than the Colorado's.
Powell has a vivid description of the building of Hoover Dam during the depths of the Depression. When you imagine what those men endured to construct it - the "high scalers", hanging on ropes using pneumatic hammers on the canyon walls to emplace dynamite, then swinging out of the way on their ropes to avoid being blown to bits. The book also describes the horrible working conditions endured by the workers, exacerbated by the parsimony of the consortium of companies running the project.
He goes into great detail about the Colorado River Storage Project and Reclamation's desire to build a dam at Echo Park in Colorado, in Dinosaur National Monument. The Yampa River joins the Green River at Echo Park and environmentalists, led by David Browder, then of the Sierra Club, fought this plan, more so than a high dam at Glen Canyon (later regretted by Browder and others). His account of Browder, with his 9th-grade education, disproving Reclamation's evaporation calculations, is priceless. The enviros won at Echo Park but in exchange for allowing a high dam at Glen Canyon to go forward.
The book has its cast of characters: besides David Browder, there are John Wesley Powell (no relation to the author?), Luna and Aldo Leopold, Floyd Dominy, Delph Carpenter, Wayne Aspinall, Morris (Mo) and Stewart Udall, Wallace Stegner, Marc Reisner, et al.
The last parts of the book are what I am really interested in - the "thinking about the unthinkable" part. In Part Four, "River of Limits", Powell discusses "a new climatology", especially that based upon dendrochronology - tree-ring analysis. Powell cites tree-ring work suggesting that the long-term mean annual flow of the Colorado is 14.6 MAF, 0.4 MAF lower than the 'official" estimate Reclamation and others use. Note that one older tree-ring study suggested a mean annual flow of only 13.2 MAF.
Powell faults Reclamation on two specific counts: 1) it uses the 15 MAF figure; and 2) does not factor climate change effects into its CRB model. Even if Reclamation distrusts the work of people like Barnett and Pierce, it could still use its own model with its own climate-change scenarios and use multiple simulations to develop probabilities. It is interesting to note that Reclamtion's simulations show Lake Powell continuing to gain water till 2030, then dipping slightly. In fact, the possibility that Lake Powell will reach dead pool - the lake level at which no more water can be withdrawn - is believed to be so remote a possibility that it does not appear on Reclamation's charts.
Powell then briefly describes how others can simulate the future of the CRB by using spreadsheet-type models that are similar to, but simpler than, Reclamation's model; WaterSim from Arizona State University's Decision Center for a Desert City (DCDC), is one such model. These models mimic the results of Reclamation's model, but when used with climate-change effects, they show drastically different results. Powell used the CROSS (Colorado River Open Source Simulator) model with what he felt were more realistic assumptions, namely the lower mean annual flow and the effects of climate change. His simulation, when plotted with Reclamation's, show differences of up to 20 MAF in a given year. Furthermore, he shows that after 30 years, there is enough water for only Lake Mead or Lake Powell, but not both. Reclamation's model shows both reservoirs with plenty of water for the entire 21st century.
The graph below shows the results of Reclamation's model (dark curve) and Powell's (light curve). Total live storage in both Lakes Powell and Mead is plotted on the y-axis is in MAF, from 0-60 in increments of 10 MAF, and the x-axis spans the years 2008 to 2101.
Powell also mentions a report done for the Sonoran Institute, Ecosystem Changes and Water Policy Choices: Four Scenarios for the Lower Colorado River Basin to 2050, in which the 'dry scenario' shows a 40% reduction in the Colorado River's flow by 2050.
So what happens next? Well, after meandering through the realm of cloud seeding (can't prove it works, but can't prove it doesn't, either), Powell then gets on with the "unthinkable" scenario, which builds to the passage that began my Part 1.
My tale ends, right? No - I'll have a Part 3 in a several days.
Then I will need to rest.
"Westerners call what they have established out here a civilization, but it would be more accurate to call it a beachhead." -- Marc Reisner, Cadillac Desert, p. 3.
Michael -- thanks for taking the time to summarize this interesting book for us. I have three comments:
1) Reclamation's projections are often flawed because they have a political agenda to build/operate dams. I wouldn't even pay attention to their simulations. Too bad for the real scientists at BurRec (I've seen the same at USGS and USACE.)
2) Barnett and Pierce did NOT use economics in their simulations. Increasing the price of water as Lake Mead empties would prevent a "dead pool" More here:
http://aguanomics.com/2008/02/lake-mead-in-trouble.html
3) The political-economic story behind Hoover is VERY interesting. LADWP drove the charge for a high dam, claiming a drought when there wasn't one (cf. Chinatown). You can read about it in Section 3.2 (3-4 pp) of my dissertation....
http://ssrn.com/abstract=1129046
Posted by: David Zetland | Tuesday, 06 January 2009 at 12:30 PM