( 20 ) 



. 



terrain is far too steep to employ ploughs and here the work has 

 to be done by hand and in aome places the sides of the cliffs are 

 too precipitous to be worked at all. Ploughing should commence 

 in October and, if possible, be completed before the hot weather ; 

 usually only one ploughing is resorted to. To serve the purpose 

 of seed beds and to hold up the rain-water in pools alongside the 

 future seedlings, contour ridges are constructed of broken earth 

 measuring roughly two feet wide and one foot high and connected at 

 intervals with cross ridges to localize damage from water breakage 

 Furthermore, dams are constructed at suitable intervals from the 

 heads of the ravines downwards, to hold up all surface water 

 flowing from the upper levels : in this way a very large amount of 

 rain-water is conserved during the critical stage of germination and 

 sinks into the ground instead of running to waste. It is found 

 by experience that as soon as grass and tree-growth is established 

 all run-off practically ceases. The fixing of sites for the dams 

 requires considerable experience, the cheapest sites are usually the 

 worst in practice, everything depends on the position of the waste 

 water escape which should be a natural one if possible. Below 

 is given a diagram of a dam or bandh with certain specifications : 



(1) The bed of the ravine to be cleared of kankar and bajri 



(2) The escape drain to be dug out first and the earth to be 

 thrown on to the bandh, surplus earth required to complete 

 the bandh to be removed from the high land on either side of the 

 ravine. 



(3) The earth in the bandh to be completely broken up with 

 wooden hammers and consolidated 



(4) The depth of the escape should be so arranged as to allow 

 water to overflow at two-thirds the height of the bandh. 



(6) The escape should be at least 10 feet wide at the bottom, 

 with an inner slope of 1 : 1. 



(6) The depth of water behind any bandh should be so regu- 

 lated as to prevent it reaching the toe of the proceeding one. 



(7) The height of the bandh should be one-half times the depth 

 of water, if the depth of the water is four feet, the full height of 

 the bandh will be 4' x l' = 6'. 



(8) The minimum top width is five feet. 



(9) The bottom width to be equal to three times the height of 

 the bandh plus eight times the depth of water in the bandh. 

 Suppose the height of banih to be 6' and the depth of the water 

 is 4', then the bottom width 6' x 3 plus 4' x 8 = 60'. 



(10) The inner slopes of the bandh should be 3 : 1. 



(11) After finding the top, bottom width, and inner slope of 

 bandh, the outer slope will be ascertained by itself. 



