Identifying a Location for the Construction of a Dam

One of the best places for building a dam is a narrow part of a deep river valley; the valley sides can then act as natural walls. The primary function of the dam’s structure is to fill the gap in the natural reservoir line left by the stream channel. The sites are usually those where the gap becomes a minimum for the required storage capacity. The most economical arrangement is often a composite structure such as a masonry dam flanked by earth embankments. The current use of the land to be flooded should be dispensable. Significant other engineering and engineering geology considerations when building a dam include:

1. Permeability of the surrounding rock or soil
2. Earthquake faults
3. Landslides and slope stability
4. Water table
5. Peak flood flows
6. Reservoir silting
7. Environmental impacts on river fisheries, forests and wildlife (see section 31.13, Functions of a weir)
8. Impacts on human habitations
9. Compensation for land being flooded as well as population resettlement
10. Removal of toxic materials and buildings from the proposed reservoir area