Recharge shaft
Recharge shafts are used when a poorly impervious
layer at the surface recharge impedes the water to recharge the aquifer whose
water table is deep below the surface. If the layer is devoid of faults and
non-caving type, it may be dug manually. By constructing recharge shaft in
tanks, the additional water may be used to recharge GW. The recharge shaft is
made up to the size of 2 m in diameter and it terminates at the permeable layer
just below the top impervious layer. However, the shaft may not reach to the GW
table. These shafts are highly impressive for ponds below which a shallow clay
layer impedes the deep percolation of water to the aquifer.