Kenya sand dams
Provision of water to Kenyan communities in ASALs (arid and semi-arid lands)
MCC has been working with sand dams for more than a decade, in multiple countries in East Africa. Sand dams are a technology used to harvest water in regions where water is limited. This water is used for both household and agricultural purposes, both freeing time for communities that no longer need to walk long distances, and opening up possibilities of activities that were not previously feasible. Generally, communities provide labour to build the dams, while organizations such as MCC partners Utooni Development Organization and Sahelian Solutions Foundation provide materials and expertise.
A number of studies and evaluations have documented the performance and benefits of sand dams. None-the-less, there were some important gaps in our knowledge about sand dams that we wanted to investigate, in order to improve the usefulness of these activities. The studies provided a large amount of data, we highlight two central questions and findings here:
Is water from sand dams clean? This makes sense - water filters through the sand, much like a giant biosand filter. But this has not be systematically studied, so we visited multiple dams and measured bacterial levels (fecal coliforms). In short, water from sand dams was not as clean as was assumed.
How well do sand dams function? We measured multiple parameters that represent the dam's physical function (how much sand is there? how much water is there?), and the dam's social function (do people use the water?). From these, we created a single integrated rating of dams. These ratings indicated that most dams work fairly well. Relatively few work "perfectly" and relatively few are effectively nonfunctional. The main hurdle to their success seems to be social - many dams seemed to have water that was simply not being used as much as it may be.
Selection of 97 dams from the region shown per their integrated rating of dam functionality. Dams with "0" rating are broken, those with ratings closer to "1" are highly functional.
Those are very short soundbites of what was found; there is a lot more we studied. Some of that is on summary sheets of our findings concerning both how clean water is at sand dams, and how well the sand dams are working; contact us about the full report if interested.
Case studies found here show what we found at sand dams in Kitui, Machakos, and Makueni counties, Kenya.