Environmental Impacts of small hydropower The impacts of small-scale hydro schemes are likely to be small and localized, providing best practice and effective site planning are used. Nevertheless, SHP still has an impact on the environment whether large or small. The factors that harm a river habitat with large hydropower projects are also present with small projects: interrupted water flows, barriers to animal movement, water loss from evaporation, involuntary population displacement and loss of biodiversity from the sacrificed portion of river are some examples. The most obvious and difficult impacts to mitigate are those on fish and the river morphology with all its consequences in the flow, sedimentation, continuity, water quality and so on