Biological and water-harvesting measures for gully control

Abstract

The Arpolo gullying control project in the West Pokot Region of Kenya is described. This is an example of conservation work done to protect the Arpolo dispensary which cost >KES350,000 to put up and serves about 3,000 people and is threatened by a fast-growing gully. The initial proposal for a concrete wall in the first phase of implementation was not feasible since it would be undermined during the rains. The alternative was to plan, design and apply water-harvesting methods and implement biological measures that would reduce the erosive energy of the surface runoff. The design of the water-harvesting structures is shown. The success of the project shows that land and water management requires skillful planning and design, especially where soils are vulnerable to erosion. The physical and chemical properties of the soils in the area are described. Given proper hydraulic designs, water-harvesting measures are still a reliable means of soil conservation.