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Building the sand dam (and wing wall)
[[Image:SandDamConstruction.JPG|thumb|right|200px|Sand dam under construction. Somaliland. Eric Fewster, BushProof / Caritas]]
* The method depends on the type of dam and the type of ground. The construction of sand dams in cascades improves total storage and efficiency and minimizes seepage losses. Dams made of concrete, stone-masonry (cheapest and easiest) and brickwork require skilled labour for construction, but are stronger and have a longer lifespan.
* Key into banks (sub-surface dams) or construct wing walls to avoid erosion around edges of the sand dam. Where wing walls are built, a good technique is to start from with the wing walls and work inwards to the centre, since community enthusiasm lags by the time wing walls are constructed (if not built first), yet they are essential to proper functioning. Length of the wing wall varies according to bank characteristic: loose riverbanks, 7 metres; hard soils, 5 metres; hard & impermeable soils or rocks, wing wall is not needed. Planting napier grass along upstream riverbanks controls erosion and fixes the course of the river in a flood.
* The height of wall built before each flood event should not exceed accumulation rate of coarse to medium sand during that flood event, otherwise ponding & silt deposition will occur, which can lower specific yield and higher capillarity, then lead to limited extraction rates in wells upstream and more water lost to evaporation. Dams at 1.3m depth showed that where finer material content (0.063 mm or less) is increased, specific yield is known to decrease remarkably. Accumulation rate and therefore height varies according to location and should be adjusted at each site after the first flood event demonstrates the rate of accumulation. Height per stage will probably be between 0.3 metre and 1 metre per stage according to experience from past projects. Some silt deposition will always occur as velocities decrease toward the end of the flood event; the idea is to limit its quantity in final sand volume.
* Avoid downstream erosion problems by making a protective slab (stilling basin) at the base of large stones set in concrete. Dimensions to be designed, but is not necessary where there is exposed rock bar downstream.
After the dam is built, an outlet for water extraction must be constructed for drinking, agriculture, etc.. Hand dug scoop holes are the simplest possibility, however the water can easily be contaminated. Covered wells, with hand or rope pumps protect the water much better. It is also possible to construct an outlet pipe with a tap. This however is difficult to maintain, and can weaken the dam. Meanwhile the local community needs to be trained to manage and maintain the dam.
[[Image:Sand dam scoop hole.JPG|thumb|right|200px|Women fetching water from a local aquifer through scoop hole]]
[[Image:Sand dam well.JPG|thumb|right|200px|Closed well near a sand dam]]
====Maintenance====
If done timely, the maintenance required is not costly. Small malfunctions in the dam however can lead to destruction of the entire dam. Therefore, the dam should be regularly checked for cracks and damage. Particularly after floods, and extreme temperature changes cracks are likely. These need to be repaired as soon as possible by a trained mason.
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