Dams significantly alter the natural topography and flow of rivers. Upstream of a dam, water is impounded to form a reservoir. This reservoir floods the surrounding landscape, submerging natural features such as valleys, forests, and, in some cases, human settlements. The result is the transformation of a dynamic river system into a more static, lake-like body of water. Downstream of the dam, the flow of water is often reduced and regulated. This can lead to several changes in the river's physic