In normal circumstances, traditional way to harvest rainwater in the Somalia is to collect and store the water in berkads for human and animal consumptions. A berkad is a catchment for surface run-off. In its most primitive form, this is simply an excavation in poorly permeable soil to a few meters depth. Surface run-off during rainfall is directed to the excavation. As run-off collects in the pool, clayey and silt sediments settle, eventually forming a seal at the base of the berkad. GSA support construction of the modern berkads with concrete and consist of a catch-pool before the main pool to act as a sediment trap.