Sand dams have been constructed along sandy rivers to improve the water retention capacity and quality of the landscape’s soil. Combined with more sustainable farming techniques, communities are reporting greater agricultural productivity and water security.

Nature-based Intervention:

Local Communities are building and employing sand dams, a low-cost technique to harvest rainwater. More specifically, sand dams are reinforced stone masonry walls built along rivers to accumulate sand which is later washed down during the rainy season to protect water sources from contamination and evaporation. These sand dams require very minimal maintenance and can last for 60 years or more. Water collected behind sand dams raises the water table in the surrounding area improving soil quality and nourishing crops and grazing lands. This improved soil quality in turn enables the planting of trees with a higher survival rate which sets in motion a symbiotic cycle of increased water retention capacity and soil quality improvement. The construction of sand dams was complemented by the increased uptake of sustainable farming methods including the introduction of drought-tolerant seeds, land terracing to prevent soil run-off, and the use of tree nurseries.

Overview of context and outcomes:

Climate change induced changes in rainfall have resulted in prolonged periods of drought that lead to the loss of grasses, trees, topsoil and reductions in the land’s ability to retain water. These disturbances threaten both the water security and agricultural productivity of communities in the area.