Groundwater Estimation Committee (GEC) 97 methodologies are used for estimation of recharge in both monsoon (June-September), non-monsoon (October-May) seasons.
To calculate natural rainfall recharge, rain fall infiltration factor method has been used; whereas recharge from all other sources such as canals, tanks, ponds, water conservation structures, return flow by surface water irrigation and groundwater irrigation has been calculated by using procedure described in the GEC’ 97 methodology. Return flow factor is also considered from the GEC’97 methodology. Average rainfall of the basin for deriving groundwater recharge has been taken from the six rain gauge stations established in the basin from 2004-14. Groundwater recharge is estimated in two assessment units namely command and non-command areas. Groundwater recharge in hilly area is not considered because no recharge has been taken place where slope is more than 20%. GIS is used for
delineation of the sub-basin; calculate the area for each geological unit spread in the sub-basin; identify the surface water bodies; and location map of the sub-basin