Based on the present increase in demand, our economically exploitable water should run out in the year 2005. As South Africa is a semi-arid country and rainfall patterns and seasonal rainfall varies, we have to rely on large storage dams to augment the annual supply of water from dry season to dry season. Poor land use practices, long periods of drought and flash floods cause millions of tons of valuable topsoil to wash into our rivers. This, in turn, ends up in our dams severly reducing their capacity. Soon dams end up incapable of meeting our water requirements.
Wetlands are essential.
They filter sand from the water preventing sand from entering our dams and reducing the capacity. They also prevent floods through absorption of peak flows and erosion a gradual release of water from the wetland. This minimises bed scour and flood damage downstream. The other main advantage of wetlands is that they significantly upgrade water from urban and industrial areas which passes through them. They also remove harmful bacteria from the water.