Surface water changes impact in different ways on biodiversity and climate. Both surface water gains and losses have biodiversity costs and impacts on ecosystem service provision. Damming is known to be one of the most important anthropogenic impacts on freshwater ecosystems. Dams fragment river systems and potentially block migration routes, leading to the loss of megafauna as well as changing the downstream flooding patterns and sediment deposition leading to the loss of floodplains, riparian zones and wetlands.