The Future of Large Dams in the United States
It is widely recognized that there are too many large dams on our nation’s waterways. These dams provide power, water for household consumption, flood control, irrigation water, navigation routes, and recreational opportunities. However, the adverse ecological impacts associated with the blockage of flow of a natural water system are plentiful. It seems obvious that there should be no future construction of these monstrous, ecosystem altering structures. However, the question remains of what to do with the large dams already in place. Do the benefits supplied by dams outweigh the costs? Is it economically, socially, and politically viable to decommission these “monuments” of the past, and is this even in the best interest of the ecology of the host ecosystems? What are the consequences of taking a middle road involving modifications to the structure of the dams to attempt to lessen environmental impacts, and are there any alterations which will significantly improve the health of the host ecosystems? Ultimately these questions must be evaluated for each dam, taking into consideration ecological, legal-political, socio-cultural, and economic factors, including how the surrounding communities and ecosystems would be affected by any possible alterations or removal of the structure. The Glen Canyon Dam on the Colorado River and the Bonneville Dam on the Columbia River are two interesting case studies from which to evaluate these concerns.