Named for John Wesley Powell, a geologist who explored the Green and Colorado Rivers for the U.S. in 1869, Lake Powell filled Glen Canyon after construction of the Glen Canyon Dam in the early 1960s. Opposed by environmentalists, including Edward Abbey, the Dam was built for water storage, hydroelectric power and recreation.
After reaching a maximum volume in 1983, the reservoir began to shrink in the late 1990s as climate change reduced mountain snowpack and increased evaporation. In concert, sedimentation from the Colorado and San Juan Rivers was filling its basin from below. As the lake level continues to fall and the upper feeder streams resurface, energy production will cease and Lake Powell will reach the "dead pool" state. Unfortunately, since adequate deep release tunnels were not included in the dam's design, flow through the Grand Canyon (just downstream) will be greatly diminished. A current proposal, not yet fully endorsed, is to create new channels through the adjacent bedrock before sediment fills Glen Canyon and its riverine ecosystem is forever degraded.
For a concise and readable history of this saga, I strongly recommend Life after Dead Pool, by Zak Podmore (the source for this post). He deftly weaves the political, industrial, hydrologic, cultural, geological and ecological elements of the Lake Powell debacle. My thanks to a good friend for introducing me to this fascinating book.
