b'and helped turn deserts into farms. The United States alone has now amassed more than 90,000 dams, half of which are 25 feet tall or greater.Decades ago, dams were a sure sign of progress. But thats changing.Today the American public is more discerning of dams benefits and more aware of their long-term consequences. In the past 30 years, 1,275 dams have been torn down, according to the nonprofit American Rivers, which works on dam-removal and river-restoration projects.Why remove dams? Some are simply old and unsafethe average age of U.S. dams is 56 years. It would cost American taxpayers almost $45 billion to repair our aging, high-hazard dams, according to the American Society of Civil Engineers. In some cases its simply cheaper to remove them.Other dams have simply outlived their usefulness or been judged to be doing more harm than good. Dams have been shown to fragment habitat, decimate fisheries and alter ecosys-tems.Depending on the size and scope of the project, dam removal may not be an easy or quick fix. Getting stakeholders onboard, raising the funds and performing the necessary scientific and engineering studies can take years before actual removal efforts can begin.And some projects are controversial and may never get the green light. For decades stakeholders have debated whether to remove four hydroelectric dams on the Lower Snake River in eastern Washington. The dams provide about four percent of the regions electricity, but also block endangered salmon from reaching critical habitat. The fish are a key food source for the Northwests beleaguered orcas.20'