( 106A ) 



The method of bandhing, the measurements and diagram of a 

 typical bandh are given below : 



WATER SlOt 



k--- 



--T 



Cubic contents of b<mdh='d,8 l 25 cub. ft. 



Length 45' 

 Height 5' 

 Top width 7' 

 Slopes 1 : 1 and 1 : 3 



NOTE. The flat top an-i the angles of slopes are fixed; the height (and 

 base) vary according to the site. The water level is fixed at two-thirds of 

 total height and is regulated by the level of the water escape. 



The laying-out and construction of bandhs have to be done 

 with great care, eince if one bandh in a ravine gives way in the 

 rains the dammed up watar suddenly released nearly always 

 carries away all the bandhs below. The following are the chief 

 points that require attention : 



(1) Bandhing is started at the tops of all the side ravines and 



worked down to the junction with the main ravines. 

 (The main ravines are seldom bandhed at all, because 

 if the side ravines are well done, they would be unneces- 

 sary, and if badly done they would never stand the rush 

 of water.) Every branch ravine must be bandhed. 



(2) In determining the site for a bandh, a controlling factor is 



the proposed position for the water escape. This must 

 always be as far away from the bandh as possible If 

 there is a low narrow neck which can be out through to 

 lead the flood water to another ravine, the condition is 

 ideal. An escape skirting the edge of a bar.dk will 

 very soon scour out and undermine the bandh which will 

 never survive. Frequently a well-planned bandh will 

 have a sheet of water stretching to 100 yards on the 

 up side in the rains. 



(3) Bandhs to be at right angles co the flow of water and never 



in a narrow gorge with steep banks. 



(4) The water escape must be capable of taking off all flood 



water. Its bottom level must be carefully fixed so as to 

 be about 3' below the top of the bandh. 



