Rivers are Forever Dams are Not Removing Glen Canyon Dam
» The primary campaign for Colorado Riverkeeper is to drain the reservoir called Lake Powell and remove Glen Canyon Dam. People tell us we’re loony. They look at the damming of the Colorado River as some inevitable consequence of progress. They see the engineering prowess and the massive federal subsidies that built 60 dams in the Colorado Basin over the last 100 years as an unstoppable force. But water and gravity are the only unstoppable forces at work on the Colorado River. And one thing that the engineers have always known, though few have admitted it, is that while rivers are forever, dams are not.
The Colorado River was, and remains, the key to the habitation and development of the American southwest. Through the 19th Century the nation expanded west, coming into possession of a huge amount of land with little water. The new territory presented a homeland security threat; an unsecured and unpopulated border. But without water you can’t farm, you can’t mine and you certainly can’t support a robust population. Farmers, industry and the cities of the Southwest required a dependable source of water. And the commercial potential of the region was enormous — in warm, fertile Southern California farmers can grow crops 12 months of the year, if they have the water.
After the Civil War debates raged in Congress over whether the federal government should get into the business of building railroads and dams to populate the Southwest. The government never got into the railroad business, private corporations did that. But with the Reclamation Act of 1902 the federal government entered dam building business. One of the first places the newly created dam building agency, the Bureau of Reclamation, went was the Salt River in Arizona (which wasn’t yet a state) a tributary of the Colorado River.
The Bureau didn’t focus on controlling the main stem of the Colorado until the building of Hoover Dam, completed in 1935. Hoover Dam was the kingpin — the biggest, tallest dam in the world. It set the stage for the development of the west, and damming rivers around the world. Hoover was the standard-bearer for nation-building through massive publicly funded water infrastructure projects still emulated throughout the world — when the Three Gorges in China is completed in 2009 it will take the crown as the world’s largest dam from the current title-holder, Itaipu Dam on the border of Brazil and Paraguay.
The Colorado is actually a small river fed by snowmelt from the Rocky Mountains. Some years the river hardly flows at all and in others it floods. Yet the Colorado is the lifeline of the Southwest. Turn on a tap in Los Angeles, San Diego, Salt Lake City, Las Vegas, Denver and Albuquerque and you are drawing water through hundreds of miles of aqueducts and tunnels from its many reservoirs. The Central Arizona Project, which supplies Phoenix and Tucson, is the most expensive water infrastructure project in U.S. history. Today more than 30 million people are dependent on water from the Colorado River. Every drop of river water is pre-assigned to an end user. Only in the wettest years does any water reach the river’s mouth in Mexico and empty into the Sea of Cortez; this has not occurred in ten years.
Since the passage of the Reclamation Act in 1902 the upper Colorado Basin states — Wyoming, Utah, Colorado and New Mexico — wanted an agreement to secure their access to Colorado River water. With the large federal investment in dam building secured, they were nervous that the powerful farmers and cities of Southern California would dominate decisions over Colorado River water allocation. In 1922 these seven states (Arizona ratified in 1944) and federal government signed the Colorado River Compact, dividing the annual water supply of the river in half at a line about 15 miles south of the Utah border. With the Compact in place, the upper basin states next wanted their own big dam — Glen Canyon — to ensure control of their half of the river flow.
In the 1950s, Congress held hearings on the proposed Glen Canyon Dam. State and federal water managers testified that the formula for allocating water in the Colorado River Compact vastly overestimated the river’s true average flow. In 1922 hydrologists had used the previous 20 years of flow data to estimate the annual yield of the river. They did not realize that their estimate included the wettest decade in the past 1,200 years, the 1910s. The Compact and the legal documents allocating Colorado River water promise the seven states of the Colorado River Basin and Mexico a firm 16.5 million acre-feet each year. (An acre-foot is 325,851 gallons.)
What Congress should have done in the 1950s was readjust the Compact to reflect the true average, closer to 13.5 million acre feet per year. But under political pressure from the upper basin states, Congress decided instead to double the storage capacity on the river. Glen Canyon Dam, even larger by volume than Hoover Dam, was approved. The State of California, which opposed the dam and later helped to kill two other dams proposed inside the Grand Canyon, is on record saying that Glen Canyon Dam would reduce total water supply. They were right; today this overcapacity depletes nearly a million acre-feet from the annual yield of the river through waste.
As early as 1959, scientists had determined the appropriate total amount of reservoir storage for the Colorado River Basin at 35 million acre-feet. Storage capacity above this amount would lead to a net water loss due to evaporation and seepage. With the completion of Glen Canyon Dam and other upper basin projects in the early 1960s, the total reservoir capacity for the Colorado River Basin went to 62 million acre-feet. The Colorado River reservoir system is overbuilt by 27 million acre-feet, the exact storage capacity of Lake Powell. Water managers in the 1950s argued that this extra capacity, and the loss of water it causes, made Glen Canyon Dam unnecessary. It underlies one current argument why Glen Canyon Dam must come down.
Another problem with Glen Canyon Dam is sediment that will ultimately compromise the need and purpose of the reservoir and dam — especially if they go empty as predicted by scientists. The Colorado River carved spectacular canyons, but it is not a large river — there are 25 rivers in the U.S. that are bigger. The dams and their reservoirs are massive because Bureau of Reclamation engineers understood that in addition to storing water, the dams were going to need to hold massive amounts of sediment. Tall dams also increase hydropower efficiency, provided they stay full.
All reservoirs collect sediment, which is deposited as flowing water enters the still water created by the dam. The Colorado carries a lot of sediment; its waters have been described as too thick to drink and too thin to plow. For the past 50 years, the flowing river entering the still water of Lake Powell has dumped 22 tons of sediment every 15 seconds. Proponents of the dams knew about this problem, but getting the dams built was the priority. Lake Powell (behind Glen Canyon) and Lake Mead (behind the Hoover) are the biggest reservoirs in the nation. The Bureau of Reclamation knew they needed to store as much sediment as possible and push the problem of removing sediment from the reservoirs as far into the future as they could.
A reservoir does not have to completely fill with sediment to exhaust its life span. This occurs when a reservoir is half full. Once the storage of sediment exceeds the storage of water the reservoir loses its ability to regulate flow through water shortages and floods. The dam then becomes a liability. The History Channel recently ran a show called “Life After People” in which they claim that Hoover Dam will be there for 10,000 years. For a bureaucracy, the Bureau has the slickest public relations imaginable. Gravity and water, which cut the Grand Canyon, are a potent force. Without constant management of water and sediment levels, these dams will fall. On the Colorado River this will happen sooner than one thinks because it is the siltiest river by volume in the U.S.
Yet no management plan exists, nor is there any funding mechanism to pay the astronomical cost for removing sediment from behind the dams. What will complicate matters is making sure that water supplies are not interrupted and downstream ecosystems are not damaged.
The damming of the Colorado, which began 100 years ago to supply Colorado River water to the public as quickly and as cheaply as possible, was a short-term solution that has created a serious long-term problem. The Bureau of Reclamation promoted a plan to conquer nature, rather than work with nature — and Congress accepted that program. This was not an inadvertent mistake. The administrative record reflects an understanding by scientists and engineers that dams and reservoirs on the Colorado are not sustainable over the long-term. Congress created this mess 100 years ago and compounded it 50 years ago. Today we have two choices: continue to exploit the Colorado River for short-term gain (at our peril) or begin to restore the Colorado River and make it sustainable once again.
Faced with a water crisis, today’s water managers are still working from the same 100 year old playbook. They are proposing new coal-fired plants to generate the electricity needed to pump (i.e. steal) water from the Mississippi or Columbia Rivers, and nuclear plants to desalinate sea water. This second wave of water infrastructure will be even more expensive than the first, with even greater environmental impacts.
We need to take a different path. The answer to the Colorado River crisis is simple: USE LESS WATER. Live within our means through water conservation, limiting growth and accepting what nature provides. Congress needs to pick up the debate where it left off in the 1950s. Congress must implement an effective basin-wide water management plan and install a funding mechanism to complete the unfinished business of sediment removal and decommissioning dams, instead of passing it on unfairly to the future.
We can’t take Hoover Dam out; nature will have to do that one. We can, however, manage it better to bring nature back — especially the “green lagoons” of the delta and the Sea of Cortez. And we can remove Glen Canyon Dam. The Bureau of Reclamation resists this because it will have to admit to a big mistake. But Glen Canyon Dam must come out, and the sooner the better for the Colorado River, the Grand Canyon and the rivers around the world. Because removing Glen Canyon Dam will send a clear message that a new age of smart, sustainable water management has begun. w
First Skeptic
The first skeptic of the taming of the Colorado River was John Wesley Powell, the father of water reclamation, founder of the National Geographic Society and the namesake for the nation’s second largest reservoir, Lake Powell. In 1893 Powell prophesized:
When all the rivers are used, when all the creeks in the ravines, when all the brooks, when all the springs are used, when all the reservoirs along the streams are used, when all the canyon waters are taken up, when all the artesian waters are taken up, when all the wells are sunk or dug that can be dug in all this arid region, there is still not sufficient water to irrigate all this arid region.
I tell you gentlemen, you are piling up a heritage of conflict and litigation over water rights, for there is not sufficient water to supply the land.
Powell was vilified for his stand and forced to leave his post as director of the U.S. Geological Survey by Senator Bill Stewart of Nevada.
Lower Colorado River from Space
This satellite image shows the Colorado River flowing into Lake Powell (far upper right). From there it flows south, turns sharply west through the Grand Canyon and into Lake Mead (top center). The river then flows south, where the vast irrigated farm fields of Arizona and California are visible. It has been a decade since the Colorado flowed to its delta on the Sea of Cortez (bottom left). Today the last of the Colorado River water is diverted north to the Salton Sea, historically an ephemeral lake that would fill every hundred years or so by the flooding Colorado River. The remnant lake would then evaporate, leaving salt. Formed in 1905 by a manmade levy break, the sea evaporates 1 million acre feet of water per year. It is fed with a constant flow of fertilizer and pesticide-laden agricultural wastewater leaving a massive toxic, man-made sea.
Cycle of Wet and Dry
It’s hard to overstate the ecological impact of dams on the Colorado. Fish spawn when the river rages with snowmelt in the spring; they are nurtured in the warm, calm summer. Without this natural variation native species disappear. This is what has happened in the Colorado below Glen Canyon Dam. The Gulf of California, where the river used to flow into the sea delivering freshwater and rich nutrients and sediment, is devastated. In A Sand County Almanac, Aldo Leopold describes the green lagoons of the Colorado River Delta from his 1922 trip as an abundant oasis:
At each bend we saw egrets standing in the pools ahead, each white statue matched by its white reflection. Fleets of cormorants drove their black prows in quest of skittering mullets; avocets, willets, and yellowlegs dozed one-legged on the bars; mallards, widgeons, and teal sprang skyward in alarm. As the birds took to the air, they accumulated in a small cloud ahead, there to settle, or to break back to our rear. When a troop of egrets settled on a far green willow, they looked like a premature snowstorm.
All this wealth of fowl and fish was not for our delectation alone. Often we came upon a bobcat, flattened to some half-immersed driftwood log, paw poised for mullet. Families of raccoons waded the shallows, munching water beetles. Coyotes watched us from the inland knolls, waiting to resume their breakfast of mesquite beans, varied, I suppose, by an occasional crippled shore bird, duck, or quail. At every shallow ford were tracks of burro deer. We always examined these deer trails, hoping to find signs of the despot of the Delta, the great jaquar, el tigre.
The book, published in 1949, included this epitaph for the Colorado River: All this was far away and long ago. I am told the green lagoons now raise cantaloupes. If so, they should not lack flavor.
Man always kills the thing he loves, and so we the pioneers have killed our wilderness. Some say we had to. Be that as it may, I am glad I shall never be young without wild country to be young in.
Dendrochronology
Studying the width of tree rings to reconstruct the hydrological record shows that the true annual flow of the Colorado is 13.0 to 14.7 million acre-feet — 15 percent less than the 16.5 million acre-feet reflected in the 1922 Colorado Compact. With more water on paper than in the river, we face an inescapable and potentially devastating water rights conflict.
Disappearing Reservoirs
Glen Canyon and Hoover reservoirs are currently at 50 percent capacity because of overconsumption, reduced yield due to climate change and evaporative loss. In February 2008, scientists from Scripps Institution of Oceanography published a peer reviewed study estimating that there is a 50 percent chance that the two reservoirs will be dry by 2021 if the climate changes as expected and future water usage is not curtailed. In their report, Living Rivers — the parent organization of Colorado Riverkeeper — is cited for the development of a model that can calculate the impacts of climate change on reservoir storage through the 21st Century.
The drying up of Lake Powell exacerbates the sediment problem, moving previously collected sediment towards the dam and prematurely shortening the life of the dam.
Filling Up with Muck
The Colorado River delivers 22 tons of sediment into Lake Powell every 15 seconds. Vacating the sediment from the reservoir would require two trucks rolling down the highway every 15 seconds — one to haul the existing sediment in the reservoir, and one for the sediment that just arrived. Remaining problems include where to put it and how to keep toxic agricultural and industrial chemicals in the sediment out of the water supply for 30 million people.
Dam Failure
The risk of dam failure is real. At Hoover and Glen Canyon Dams the spillways that relieve excess water are concrete tubes tunneled through the bedrock next to the dam (abutments). The spillways cannot run continuously because the power of cavitation is destructive; the implosion from the vacuum that’s created from the falling water in the closed tube at the bend, where the spilled water is ejected into the river behind the dam, literally rips out the concrete.
This photo shows one of two Glen Canyon Dam spillways after an emergency spill in June 1983. A hole 150 feet long and 50 feet deep was excavated by the power of water rushing through the tunnel. The cost to make repairs was $40 million. The Bureau of Reclamation opened the spillways to prevent water from over-topping the dam, which would destroy the power plant at the base of the dam and undermine the dam’s foundation, possibly catastrophically. If an earthquake were to damage Glen Canyon Dam, it would take up to 16 months to safely drain the reservoir.
Lower Colorado River from Space
Colorado Riverkeeper John Weisheit running Big Drop Three in Cataract Canyon. This section of 
Protesting Glen Canyon Dam