Sand dams are small concrete walls built across seasonal streams to help store water in dry areas. These dams work by capturing water in the sandy riverbeds behind them, which communities can then use for drinking, farming, and other needs. But when too much fine material like silt and clay builds up, water doesn’t flow through as easily – making the dams much less effective.

This study explored whether changing the shape of the opening at the base of the dam could help solve that problem. Through lab experiments and computer simulations, we tested several outlet designs to see which ones worked best. We found that certain shapes helped trap more coarse sand – the kind that stores water well – while allowing fine particles to flow away.

These results show that simple changes to how sand dams are built could make them work better for longer, helping communities maintain access to clean water. More research is needed to test this solution in larger setups and different stream conditions.