MAKUENI, Kenya (AP) — On a dry riverbed one recent sunny morning, residents of Kasengela village toiled away mixing cement and sand to make concrete. The sound of their shovels resonated through the valley while other residents, working in pairs, carried rocks to the site in wooden frames.
They were building a sand dam, a structure for harvesting water from seasonal rivers. The barrier, typically made of concrete, impedes water flow and coarse grains of sand settle behind it, creating an artificial aquifer that fills up during rainy seasons.
Seasonal rivers flow a few times a year here, and with little piped water and few reliable alternatives, many people here depend on them for water. Building sand dams on these rivers, where people can scoop the sand to fetch the water or use hand pumps, helps minimize water loss through evaporation and recharges groundwater. This is increasingly important as human-caused climate change is leading to prolonged seasons of drought, scientists say, and the simple sand dam solution has gained traction across dry regions of Kenya and some other parts of Africa looking for reliable water sources. But experts also warn that finding the right sites for structures is key to making them work.
Kasengela village is in Machakos County, which, alongside other counties of Makueni and Kitui in southeastern Kenya, is classified as arid and semi-arid. For many communities here, sand dams built on seasonal rivers have grown in popularity.