Lake Powell Reservoir and Glen Canyon Dam
Dam in Crisis
The following is a summary of a lecture given by Chris Peterson at the Humanists of Utah July general meeting.
Glen Canyon Dam, completed in 1963, dammed the free flowing Colorado River and created Lake Powell reservoir. The Glen Canyon Dam inundated and flooded some of America's most spectacular wilderness beauty. The current severe drought in the West is revealing what was lost to the waters of Lake Powell reservoir. This is a brief introduction to the issues surrounding Glen Canyon, the Grand Canyon, Lake Powell reservoir, and the Colorado River. Like the receding waters of Lake Powell reservoir, this introduction reveals it's not worth it!
Glen Canyon Dam was built as the final piece of the Colorado River Compact with the primary purpose of water storage to ensure water delivery to the Lower Basin states of California, Arizona, and Nevada. Lake Powell reservoir was justified to Congress in the 1950's as the perfect solution to uncertainty of water supply for the growing Southwest. It was to be the "silver bullet," providing an insurance policy for the Upper Basin States' water delivery responsibility, regulating floods, and being a "cash register" hydropower dam to pay for building dozens of other dams upstream in the Colorado's watershed. After forty years, it is clear that Lake Powell reservoir is far from the perfect solution to water supply problems in the West.
As a combined result of being lined by sandstone walls and having a large surface area in an arid climate, Lake Powell reservoir wastes significant amounts of water to bank seepage and evaporation (nearly 1 million acre-feet annually). The hydropower it actually generates contributes an insignificant amount of less than 3% to the region. Due to rapid sedimentation, the dam and reservoir are imposing significant long-term costs on the public, are unsafe, and have all but destroyed the biological resources in Glen and Grand Canyons. However, the most devastating impact of Lake Powell's development has been the false sense of water security to both the Upper and Lower Basin States, which has resulted in unsustainable growth and development.
The idea of a centralized water and electricity system has simply proven to be unsustainable. Glen Canyon Dam began life as a political decision. It exists today as a monument to the political tradeoffs of the 1950's. The Colorado River is a national resource, supported and subsidized by all Americans. Its purpose and future should be debated on a national level, not in the offices of developers.
What is Glen Canyon?
Described by John Wesley Powell as a "land of beauty and glory," and by Edward Abbey as "a portion of Earth's original paradise," magnificent Glen Canyon and its unique side canyons are unlike any in the world. Waterfalls, hanging gardens, spectacular narrows, arches, painted grottos, and picturesque alcoves abounded in the more than 125 unique side canyons. Glen Canyon also holds many secrets from the past, with more than 3000 documented ruins from ancient cultures. As the biological heart of the Colorado River, more than 79 species of plants, 189 species of birds, and 34 species of mammals lived along the stream and river terraces in Glen Canyon. River otters played in the calm waters while herons nested in the cottonwoods along the shores. Maidenhair ferns decorated the cliff walls that towered over crucial breeding grounds for humpback chub and numerous other endemic species that depended on the free-flowing Colorado River for their seasonal migration.
Glen Canyon Dam and "Lake" Powell Reservoir
In 1963, the gates at Glen Canyon Dam were closed. Lake Powell reservoir began to drown Glen Canyon, one of the world's most spectacular and unexplored riparian environments. The waters that backed up behind the dam flooded 186 miles of the Colorado River, including all of Glen Canyon and large portions of its tributaries. The fragile Grand Canyon ecosystem, which depended upon the nutrients the Colorado River picked up in Glen Canyon, immediately began to decline. Spring floods that previously deposited millions of tons of vital sediment and nutrients in Grand Canyon were halted and replaced by cold, clear, regulated flows. Since 1963, all of the sediment that should have been destined for the Grand Canyon has been trapped behind the dam. These sediment deposits are growing at a rate equivalent to 30,000 dump-truck loads every day. Native fish, which had evolved and flourished in the dynamic, pre-dam environment, have been unable to adapt, several have become endangered, and two have been extirpated from Glen and Grand Canyons.
The Ongoing Drought: The Restoration of Legendary Glen Canyon
The current drought in the Southwest, which is not unprecedented in recent history, has drawn the water levels of Lake Powell down by more than 56%, exposing hundreds of miles of "lost" side canyons and more than forty miles of the Colorado River itself. In addition, the record low water levels have shown that Glen Canyon and its side canyons possess an incredible capacity for rapid restoration. Plants and animals are beginning to return to many side canyons as returning streams wash away the sediment that had accumulated when reservoir levels were higher. Seeps of desert varnish are creeping their way down canyon walls to cover the white bathtub ring that marked the reservoir's high water levels. As the reservoir's water recedes from the canyons, it is evident that Lake Powell reservoir is not an acceptable solution to the region's water resource problems. Long-term climate models predict changing hydrologic dynamics throughout the watershed, decreasing the reservoir's storage capacity-as there may not be sufficient water in the river to refill it.
In the time since the dam was first considered, it has become increasingly apparent that the Glen Canyon Dam and Lake Powell reservoir are not worth the sacrifices that must be made to keep them in operation. The large amounts of water lost to evaporation and bank seepage, the costs to taxpayers to keep the system running, the flooding of Glen Canyon, and the continuing destruction of Grand Canyon and the Colorado River are prices we cannot afford to pay. We have been granted a window of opportunity that is revealing to us once again the wonders of Glen Canyon while bringing the debate of western water consumption to the foreground so we may see that there are other, more sustainable options for how we manage our water. The current drought is showing us now that we can reverse this great western tragedy and restore Glen and Grand Canyons.
For more information follow this link to the Grand Canyon Institute or on Chris' name below to send him e-mail.