That is not entirely a given. Large eathworks have important knock effects on the environment and wildlife. We tend to think that dams and such are harmless but

That is not entirely a given. Large eathworks have important knock effects on the environment and wildlife. We tend to think that dams and such are harmless but they change their surroundings radically. I had experience living next to one which modified the local climate and made a large contribution to the desertification of the place.