Relieving long term causes of poverty by supporting communities to implement sand dams and soil and water conservation programmes as lasting solutions to food and water shortages
Excellent Development supports communities in rural drylands in Makueni County, south-east Kenya to help the people most vulnerable to climate change improve their resilience and continue to work towards their development. The immediate effects of climate change are causing droughts to worsen in drylands. We aim to relieve long term causes of poverty by supporting communities to implement sand dams and soil and water conservation programmes as lasting solutions to food and water shortages.
A sand dam is a reinforced concrete wall built in a seasonal riverbed which captures and stores water beneath the sand. The seasonal rains fill the dam with water containing soil which is made up of silt and sand. Water is stored within the sand making up 25-40% of the total volume. Evaporation is kept to a minimum because the water is stored below the sand which acts as a filter and protects it from parasite carriers such as mosquitoes and snails. The water is then abstracted by scooping holes, pipe filtration or shallow wells with pumps.
Sand dams raise the water table around the dam, keeping more water in the area and thereby reducing aridity. Trees grow naturally, nurseries can be established and there is enough water for crops to be properly irrigated. Unlike regular dams they allow 97-99% of water and silt to flow over the dam to communities further downstream.
One sand dam can store between 2-20 million litres of water close to people’s homes, providing a year round supply of water for domestic and agricultural use for a whole community (on average 1,000 people.) Combined with soil and water conservation activities such as land terracing and tree planting, sand dams increase the groundwater levels in the area so that trees, plants and crops can grow, improving the ecosystem and enabling food security for these vulnerable farming communities.