Why build a SSD? (UC)

A sand storage dam will, like a surface water reservoir, store water during the wet season, so that it is available during the dry season. The most important difference with surface water reservoirs is that instead of storing the water
as open water, water is stored underground. In doing so, sand storage dams have several important advantages (over surface water dams), resulting in higher water quality and improved environmental conditions .

1. Groundwater is protected against evaporation. Since salinity increases with evaporation, water quality remains more constant and is better. Also, smaller volumes of water are lost to evaporation.
2. Groundwater is less succeptible to biological contamination.
3. Groundwater will have a higher water quality because the water is filtered during flow through the riverbed sand (desinfection)
4. Groundwater is unsuitable for mosquitoes (malaria) and other insects to breed in.
5. Sand storage dams are relatively inexpensive, simple structures build with a high level of community involvement and a little maintenance required.
6. The consequences of dam breaching are far less severe and dangerous compared to failure of surface water dams.
7. Building a sand storage dam has only limited social and environmental impact, since the structure will not (or very limited) interfere with current land use.
8. Silting is not a problem; the storage capacity will not be reduced due to sedimentation upstream of the dam.