2. Environmental impact

2.1 Effects of dams

• Land submergence: the construction and impoundment of a dam has an impact on land and society through the flooding of agricultural or forest land and the possible displacement of people. Reservoirs affect groundwater levels and springs, and can influence landslides on slopes. Last but not least, the water mass of large reservoirs can trigger local microearthquakes when they are first filled.

• Risk of failure: dams store enormous potential energy. Although improved construction techniques, dam monitoring and auscultation, and enhanced hydro-meteorological and geological knowledge are reducing the risk of failure, it cannot be considered zero. The main causes of failure are inadequate spillways...