5. Water harvesting techniques

Trapezoidal bunds were designed for Turkana District when a widespread food relief operation was underway in 1984. A policy of food-for-work had followed the free distribution of food at the beginning of the crisis. The first attempts at water harvesting, based on contour bunds, were not well designed or supervised. The result was extensive bunding which was not useful - and not used. The design for trapezoidal bunds was based on scientific principles and the best available data on rainfall and runoff. There was a deliberate policy to 'over-design', as food-rewarded labour was not limiting and it was desired to make the structures as maintenance free as possible. By 1987 about 150 trapezoidal bunds had been constructed for the production of quick maturing food crops including sorghum and cowpeas. The Turkana Water Harvesting Project, a small NGO in the northeast of the District, has modified the basic design for local conditions. Although the line level is used for setting out the bunds, catchment sizes are estimated by eye and the experience of locally trained technicians.