Changes

[[Image:94px-Icon_sanddam.png|right|80px]]

[[Image:Sand dam.JPG|thumb|right|200px|Sand dam construction in Kitui, Kenya. Photo: M. Hoogmoed.]]

Sand dam projects here have not only improved water availability, but benefited the community socially and economically. Locals are trained to participate in construction of the dam, maintenance, financial management, and also in natural resource management.

[[Image:Sand dam flood.JPG|thumb|right|200px|Sand dam during flooding. Photo: [http://www.rainfoundation.org/index.php?id=151 RAIN Foundation.]]]

|}

====Drought====

'''Effects of drought''': Can dry up; Water yields low. <br>

Sand dams require careful maintenance, and immediate repair, as flooding causes hundreds of tons of water to fall over the dam wall and onto the spill-over apron. Flood water may also spill over and erode the wing walls and, perhaps, even over the riverbanks during heavy rains. When determining the dam and spillway height at the selected location, it is very important that the water level and flood line remain below the riverbanks after construction of the dam, or that flooding will not lead to problems up or downstream of the dam. If the flood level is higher than the riverbanks, construction of a dam is not advisable.

[[Image:Sand dam diagram.JPG|thumb|right|200px|Cross section of a sand dam.<br> Diagram: Netherlands Water Project. <br>Click image to see details.]]

[[Image:Sand dam trench.JPG|thumb|right|200px|People excavating a trench. Source: [http://www.sswm.info/category/implementation-tools/water-sources/hardware/precipitation-harvesting/sand-dams RAIN (n.y.)]]]

The lifespan depends on the materials used and expertise with which it is constructed and maintained. The dams in Kitui Kenya were built at a cost of US$7,500 and have a minimum lifespan of 50 years.

The construction of dams is largely carried out by the local community. Costs mainly relate to local availability of cement, masonry and professional supervision.

The cost to benefit ratio for the sand dam's first year of operation is 1:12.

In Kenya, it has been used with good outcome in the Kitui, Machakos and Samburu districts. Other countries with similar dry environments such as the U.S.A, Thailand, Ethiopia and Namibia also have used it in numerous and diverse forms.

|}

* MANUAL: [http://www.rainfoundation.org/fileadmin/PublicSite/Manuals/Sand_dam_manual_FINAL.pdf A practical guide to sand dam implementation]. Rainwater Harvesting Implementation Network (RAIN).

* MANUAL: [http://www.samsamwater.com/library/Manual_on_SAND_DAMS_in_Ethiopia.pdf Manual on sand dams in Ethiopia]: A practical approach on sand dam site selection, design and construction. A tool for combining sand dams with other rainwater harvesting structures. ERHA (Ethiopian Rainwater Harvesting Association) and RAIN Foundation.

* [http://www.iah.org/recharge IAH]. IAH-MAR is a forum for information on the work within the international groundwater community on the management and enhancement of aquifer recharge, a vital tool in the sustainable management of the world's underground water resources.

* CARE Nederland, Desk Study: [[Resilient WASH systems in drought-prone areas]]. October 2010.

* Brikke, François, and Bredero, Maarten. [http://www.washdoc.info/docsearch/title/117705 Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff] or ([http://www.who.int/water_sanitation_health/hygiene/om/wsh9241562153/en/ alternative link]). World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.

* Maddrell S and Neal I, [http://www.samsamwater.com/library/Maddrell_and_Neal_2012_Sand_Dams_a_Practical_Guide_LR.pdf Sand dams: a Practical Guide], Excellent Development, London. 2012.