Free-flowing rivers in the United States are an endangered species. With more than 500,000 dams in place, we’ve dammed and diverted almost every major river, straightening curves and blocking passage for fish and other aquatic animals, pushing many to the brink. Now a heartening new movement is helping to demolish harmful or obsolete structures and restore new life to rivers and the communities that depend on them. In doing so, it offers a pathway to undoing environmental harm to nature—an...

Free-flowing rivers in the United States are an endangered species. With more than 500,000 dams in place, we've dammed and diverted almost every major river, straightening curves and blocking passage for fish and other aquatic animals, pushing many to the brink. Now a heartening new movement is helping to demolish harmful or obsolete structures and restore new life to rivers and the communities that depend on them. In doing so, it offers a pathway to undoing environmental harm to nature—an...