SWC works in Wadi plots are built according to rainfall and slope of land as follows:
In high rainfall (>1000mm annually) areas with slope less than 10%, water absorption trenches with soil or stone bunding are constructed across the slope, along contours. In areas with low to medium rainfall (500-900mm), and gentle or variables slopes, staggered contour trenches with soil or stone bunding are built.
Trench size is generally 2m x 0.60m x 0.60m and bund height is 0.45m when stone is used, and 0.80m when soil is used.
Distance between two bunds is matched with spacing between rows of trees and varies from 10-20m.
In high rainfall areas at least 3 outlets or an open channel are provided per plot of 1 acre, for safe disposal of surplus water.
Earthen contour bunds
In areas with scanty or erratic rainfall, and slope less than 10%, earthen bunds are built along contours. Bunds are constructed out of soil excavated from pits of 1 to 3m width and 0.3m depth, and at a distance of 3m from the proposed bund, on the upstream side of the bund. Width of pits varies according to quantity of earthwork required. Pits are later filled up by ploughing. Multipurpose tree species may be planted on the bunds.
Platform and trench
In hilly areas, with slopes more than 15%, a platform and trench is built around each tree. Platforms around trees are in the shape of a half moon, with a radius of 2m, and have sloping sides. The platform is constructed with locally available stones or soil clods, or by filling murum. Height of platform varies according to the slope. A trench of 2m x 0.60m x 0.60m is dug on the upstream side of tree.