What are the methods suitable for areas with clay sub-soil and hard rock areas?
Since clay sub-soil formation is impervious in nature and is having poor permeability, deep recharge structures such as percolation pit with bore, recharge trench with bore and deep/large recharge wells are needed for deep percolation into the underlying sandy layer. For hard rock areas it is advisable to construct recharge wells the size of which depend on the extent of the area/building.
