'• Regulating and damming of rivers affect their natural flow causing poor sediment flow and excessive sedimentation at the bottom of the reservoir, resulting in rockier stream beds and poorer habitats for the riven' aquatic life. • Dams also fragment rivers making it difficult for aquatic fauna to migrate, especially for spawning. • The reservoirs that are created on the floodplains also submerge the existing vegetation and soil leading to its decomposition over a period of time.