ABSTRACT
This chapter deals with water harvesting techniques for irrigation purposes, and only short-term storage facilities. Water harvesting is the collection of runoff and its use for the irrigation of crops, pastures, and trees, and for domestic and livestock consumption. The design principles of a water harvesting project are similar to those of other hydraulic projects requiring a wide range of input. Crop Water Requirements are a function of the specific crops to be grown and the climatic conditions. Trapezoidal bunds are used for planting either field crops or trees. The layout of an area includes a tier of trapezoidal bunds along a contour line. Retardance dams (sometimes called check dams) are small stone or gabion structures which are built across seasonal rivers to retard or check the flood flows. A variation of the check dam is the so-called "underground dam", which is a vertical barrier constructed across the bed of a stream below the ground surface.
