Old reservoirs have new capabilities.
The world has a multitude of reservoirs. Usually, and properly, the dams that retain the water were built with immense caution. Their designers were especially worried about dam failures, floods and water pollution. Today, there is less to fear. Hydrological and structural monitoring give advance warning of floods and faults; filtration equipment removes pollution. These changes have made existing reservoirs into potentially rich places for landscape development. Future reservoirs can be developed as multi-functional projects for wildlife, swimming, boating, fishing, waterside building, power generation, irrigation, river regulation, scenic enhancement and, occasionally, great works of art. Existing reservoirs should be assessed and made subject to EID. They are capable of yielding more private and public goods than they do at present.
Should Hetch Hetchy be submerged for a reservoir, as proposed, not only would it be utterly destroyed, but the sublime canyon way to the heart of the High Sierra would be hopelessly blocked and the great camping ground, as the watershed of a city drinking system, virtually would be closed to the public.
John Muir 1912:259
Hetch Hetchy Dam, which flooded a valley as wonderful as Yosemite to supply San Francisco, most certainly would not be approved today. It destroyed a valley and led to the above complaint from the founder of America’s national parks. In Britain too, the main reason for building dams has been to store water for domestic supply. Public health