Hydrogeology and siting of micro-dams around Léo Burkina Faso

Hydrogeology and siting of micro-dams around Léo, Burkina Faso14 June 20103 Micro-dams constructed in 2008-20093.1 IntroductionDuring the mission 3 sites were visited where dams were constructed in 2008 and 2009 by CREDO, 5proposed sites for dam construction and (on request of CREDO) 2 additional potential sites for damconstruction.The locations of all dam sites (and their catchment areas) are presented in Figure 7. The three siteswhere a dam was constructed in 2008-2009 will be discussed in the following paragraphs. Theproposed and potential sites will be discussed in the next chapters.Figure 7 Locations of micro-dams and proposed sites. The green line indicates the catchmentarea of each dam site.Details on the population, the number of water users and cattle per site was collected by CREDO inthe document “Les données sur l’exploitation des anciens micro-barrages et nouveaux sites” (CREDO,2010). This document is reproduced in Appendix 2.3.2 SangaThe micro-dam of Sanga is located about 9.5 km East of Léo. The dam is constructed betweenNovember 2008 and March 2009. More details on the dimensions and construction can be found in“Description du barrage de Sanga, révisé” (Henk Haas, 2008). The catchment area of this dam has asurface area of 2.8 km 2 (the smallest of all visited sites).At the time of visit the water level was 1.34 m below the level of the spillway. According to thevillagers the surface water never dries up completely, although the area greatly reduces near the endof the dry season. At the time of visit the surface water covered an area of about 3,000 m 2 . The8