nother rapid was lost this year due to the hand of man. Ironically, the loss of this rapid did not make front page news in any newspaper, as did the demise of Quartzite Falls on the Salt River in 1993. The rapid is called #27, better known as Imperial in Cataract Canyon, and its loss is attributed to the rising levels of a reservoir called Lake Powell.
During most of the 1980s, Imperial Rapid was under the waters of a full Lake Powell. Yet by 1991, with diminishing reservoir levels, Imperial extended a full mile and my hopes were high that Waterfall Rapid (#28) too would soon be reclaimed. It is my understanding that Waterfall was a real “whoops aha” rapid; alas, it did not surface.
The combined snow melts of 1993 and 1995 helped bring the level of Lake Powell to within 10 feet of full pool, which is 3700 feet above sea level (asl). If the lake fills next year, we will also lose Rapid #26 and part of Rapid #25 (the top of Rapid #25 is 3700 asl). And let’s not forget that this also includes the rapids of the San Juan River, as well as camps on the lake that are so desperately needed for these river trips.
It is intolerable to me that the Bureau of Reclamation (BuRec) wants to increase the potential pool capacity of Lake Powell yet another 4.5 feet by implementing a spillway enhancement project (GCD DEIS, page 36). When the lake is then full at 3704.5 feet asl, we will also lose Rapid #24. Granted these rapids will be lost and recovered during the continuing low/high pool history for Glen Canyon Dam. However, these rapids too may eventually silt in as did Waterfall Rapid.
The spillway enhancement should not be built. It will only waste time and money to increase the lake’s storage capacity since the volume gain would soon match the ever growing rate of sediment fill. For this reason, this “flood frequency reduction” measure attached to the Preferred Alternative is unacceptable, as it degrades the quality of a river experience in the upper basin. As this is contrary to the mission statement of Colorado Plateau River Guides (CPRG), the river guide association of the upper basin, we intend to fight this proposal. In view of collaboration, we would support the “floodflow avoidance measure” as proposed in the No Action Alternative, which states “Storage in Lake Powell is not to exceed 22.6 maf as of January 1 of each year in preparation for storing and regulating spring run-off.”
I believe that Glen Canyon Dam is unsafe and that it should be decommissioned as soon as possible before the downstream and upstream environments are further trashed. Personally, I am not convinced that the dam is going to endure to the day when the sediment elevation matches the penstock inlet elevation, the planned day of obsolescence. I feel this way because the bedrock for the abutments and the spillways is a water permeable Navajo sandstone. Should this bedrock fail and a breached flow of, say, 400,000 cfs comes crashing through Grand Canyon, all those fun boulder-choked rapids will be gone too; probably washed out to be redeposited as big gravel bars downstream.
So far, the spillways haven’t been tested to survive an inflow of over 220,000 cfs, such that would have occurred in 1921, nor an inflow of 300,000 cfs, such that would have occurred in 1884. In 1983 the spillways failed disastrously when the inflow was only 120,000 cfs. In 1984 BuRec repaired and modified the spillways, tested the left spillway at a maximum flow of 50,000 cfs, for a period of one hour, and called it good. I am not convinced.
I feel that any high pool and/or spillway use scenario for Glen Canyon Dam has the potential to negate the ideals set forth in the Grand Canyon Protection Act. When considering this bigger picture, the only real alternative worth considering is dam removal. The GCES process should have included engineering reports related to the integrity of this dam that is constructed into a sandstone that is growing weaker with each passing decade. I realize that dam removal negates the ideals of the Colorado River Compact, but the accumulation of sediment in the reservoir is going to determine this eventuality for us anyway. I would hope that as a society, we would have the courage to start the dam removal process right now.
Decommissioning the dam would make for that transcendent New Year’s Day I so desire. This very act alone might generate the new technologies we so desperately need to bring lasting energy and water to the citizenry. Imagine the powerful message that would be sent to the developing countries if we, the biggest energy consumer of the world/agribusiness giant, willingly decided to remove Glen Canyon Dam!