This project is based (loosely) on the Glen Canyon controversy, which was reported on National Public Radio on Saturday, October 20, 1990. The amount of electric power required throughout the day by a power grid for distribution is given by the graph below. Early morning when people get up and get ready to go to work, school, etc., and evening when people come home are called "peak power periods." It would be expensive to build enough power plants to supply peak power demands 24 hours a day, so utilities look for peak power sources. Hydroelectric power is particularly good for this type of use since simply letting more water flow through the facility gives an almost instantaneous increase of power. (Firing up a new generator takes much longer.) The dam produces 2 megawatt hours (a megawatt hour is enough energy to provide one megawatt of power for one hour) for each 90,000 cubic feet of water per hour that flows through the hydro-facility. The other fossil-fueled plants in the grid consistently generate 4.5 megawatts. In order to avoid power outages and have sufficient reserve power the Public Utility Commission requires the utility to generate at least 6.5 megawatts at all times as well as generating 0.5 megawatts above the demand for power. megawatts 8 7 6 5 12 midnight 6 A.M. 12 noon 6 P.M. 12 midnight Demand function The water flows into a canyon. (Water released by the dam is the only source of water for the water that flows through the canyon.) The canyon below the dam contains spectacular scenery and is part of a national park. Many tourists visit the park to enjoy the scenery; in addition, over the last few years many wild water rafting companies have prospered using the ride through the canyon. However, at some times during the day there is not enough water in the canyon for the rafts to make a trip through the canyon. Also, the trips depend on the existence of beaches which enable the rafts to stop and rest inside the canyon. Finally, environmentalists are worried that the peak power use of the dam will destroy the canyon because of increased erosion.