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the alternative would have caused significant problems for the adjacent U.S. Highway #34 since the highway would have required significant raising of its elevation. This action would have resulted in grades in excess of 6%. This alternative was analyzed and it was found that this dam would cost two times as much at this location versus the old location. Further it was calculated that anchoring both abutments to solid rock was not essential for protection against the 100 year flood if the base of the dam were anchored to bedrock. Since bedrock is only 15 feet below the stream bed the above alternative was not selected. 2. Replace the hydroelectric plant at the same location as the old plant: This alternative was quickly discarded for the following reasons: (a) The old power plant site is in the 100 year floodway; and (b) the old site is in the water trajectory caused by a flash flood striking the canyon wall at an angle that causes the rushing water to rebound and rush directly to the old power plant site. ft~ 3. Abandon the project entirely and purchase replacement power from Platte River Power Authority: This alternative was analyzed from an economic viewpoint and it was found to be monetarily advantageous to the City to rebuild the project. The economic analysis (Appendix C) attests to the fact that the project not only can generate sufficient funds to replace itself in forty years, but it also generates an additional cost savings of over $100,000 for each year of its existence. Therefore this alternative was eliminated from further serious consideration. r ,'I' K. Design Provisions to Reduce Adverse Environmental Impacts and/or Enhance the Environment. The flood of 1976 destroyed millions of dollars worth of private property and took 139 lives. In addition, not only did it destroy the dam and power plant located in or near the Big Thompson River, but the high velocity of the rushing torrent of water did significant damage to the river itself. In some areas the path that the river had followed for over fifty years suddenly was changed only to leave the dry scars of the former stream. In others large and numerous rocks and boulders were heaped up in the middle of the stream causing visual pollution of the former natural and graceful flow of the Big Thompson. In still other areas river banks heretofore thought to be permanent were gouged out by the 31,000 cubic feet per second of rushing water. U.S. Highway #34 running adjacent to the river was totally washed out in much of m ~!.~ t~--; ,...., 23