| Issue
Geological uncertainty and the possibility of earthquakes can introduce construction, safety and financial risks for developers of hydro schemes in particularly prone areas.
Some dams are built in areas with known seismic activity, and some are built directly on or in a region of fault lines. In some locations reservoir induced seismicity can result from the weight of water filling a new storage. This triggered seismicity is likely to be low level earthquake activity that occurs in the vicinity of artificial reservoirs as a consequence of impoundment, and is the result of tectonic loading associated with water storage and the depth of the water column.
Most dams are designed to cope with seismic risk and usually seismic activity results in no damage; however if not adequately considered in the project siting and design stage, adverse consequences of an earthquake/seismic event can ensue. At a minimum it may lead to costs to repair dam walls and associated infrastructure, and in a worst case scenario it could lead to dam failure with high cost the community, the environment and power supplies. Clearly, understanding seismic risk is important for siting, design and construction decisions as well as for financial reasons. |
