Subsurface method

1. Recharge well

Recharge wells are used to recharge water directly to the aquifer. Recharge wells are similar to pumping wells. This method is suitable to recharge single wells or multiple wells. This method is costlier than the other method as wells are required to be bored. However, sometimes abandoned tube wells can be used for recharging water into the aquifer.

2. Dug well

Dug wells can also be used to artificially recharge the groundwater. Generally, water level of dug wells depletes during the non monsoon period. Sometime the dug wells even dried up in the non-monsoon period. These dug wells can be used for recharging groundwater. The water from various sources can be collected through a distribution system and can be discharged at the dug wells.

3. Pits and shafts
Recharge pit of variable dimensions are used to recharge water to unconfined aquifer. Most of the time, especially in case of agricultural field, a layer of less permeable soil exist. Due to the existence of the less permeable

permeable strata, the surface flooding methods of recharge do not show satisfactory performance. For such type of cases, recharge pit can be excavated which are sufficiently deep to penetrate the less permeable strata. On the other hand recharge shaft is similar to the recharge pits, but the cross sectional size of the recharge shaft is much lesser than the recharge pits. Like the recharge pits, recharge shafts are also used to recharge water to unconfined aquifer whose water table is deep below the land surface and a poorly impermeable strata exist at the surface level.