Hydroelectric dams can mitigate the ecological impact. Hydroelectric dams can take steps to mitigate their environmental impact. For example, for salmon, dams these days have ‘fish ladders’, allowing them to reach their spawning grounds. For these and other sustainability measures, the International Hydropower Association developed several guidelines and protocols to minimize ecological impact as far as possible. [1]  [1] International Hydropower Association, Hydropower Sustainability Assessment Protocol.