Riverside forests across Alberta, Canada, are dying off as a result of too many dams on the Bow River and other important waterways. The dams create reservoirs for drinking water and irrigation, prevent flooding, and generate electricity — but at a steep price, say Alberta environmentalists. Natural floods in the river valleys spread water and nutrients, promote germination of seeds, and keep forests thriving. Without them, forestry experts say, the Bow and other Alberta rivers will lose all their trees within the next 100 years. Short of undamming the rivers, the only other option is a massive replanting effort, on the order of tens of thousands of trees for the Bow River alone.