Water from Small Dams

The usual types of pit latrines with walls of burnt bricks and tin roofs are expensive and,due to poor craftsmanship, some latrines collapse during rainy seasons. Lack ofventilation pipes also give latrines bad smell and encourages flies.A new type of latrine, the AborLoo, can be built for the cost of only one bag of cement,for making the slab. The walls and roof are made of locally available materials such asmats or sticks. The pit is dug to only 1 metre depth and covered with the slab. Dry soilmixed with wood ash is placed in a corner of the latrine and a handful of it dropped intothe latrine after use, to avoid bad smells and facilitate the process of composting. Whenthe pit is almost full, a new pit is dug nearby and the slab and walls are transferred to thenew pit, and a tree is planted in the fertile soil of the old pit.The removable slab for an Aborloo. An Aborloo with walls of grass.Source: Ecological Sanitation in Zimbabwe by Dr. Peter Morgan.8.2 Catchment protectionIt is important to implement catchment protection, also called soil conservation, on theland from where rainwater runs off into the dam reservoirs. Otherwise layer upon layer ofsilt and soil will fill up a dam reservoir, thus reducing the volume of water it can hold.In the worst scenario, dam reservoirs will be filled to the brim with soil and cannot holdany water at all. Since de-silting of such reservoirs is more expensive than building newreservoirs, silted-up dams are often abandoned altogether. However, for dam reservoirssituated on sandy soils, a thin layer of siltation is beneficial because the silt seals the floorof a reservoir against seepage.52