Effective recharge of aquifers, a sustainable approach to enhance groundwater

An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials. There are two general types of aquifers: confined and unconfined. Confined aquifers have a layer of impenetrable rock or clay above them, while unconfined aquifers lie below a permeable layer of soil. In order to access this water, a well must be created by drilling a hole that reaches the aquifer. While wells are man made points of discharge for aquifers, they also discharge naturally at springs and in wetlands. Aquifers are natural filters that trap sediment and other particles (like bacteria) and provide natural purification of the ground water flowing through them.

Aquifer recharge (AR) and aquifer storage and recovery (ASR) are man made processes or natural processes enhanced by humans that convey water underground. The processes replenish groundwater stored in aquifers for beneficial purposes. AR is used solely to replenish water in aquifers. ASR is used to store water, which is later recovered for drinking water supplies, irrigation, industrial needs, or ecosystem restoration projects. Injecting water into AR wells can prevent saltwater intrusion into freshwater aquifers and control land subsidence.

Several methods of introducing water into an aquifer exist including surface spreading, infiltration pits & basins and injection wells. Injection wells are used for AR and ASR in areas where surface infiltration is impractical. Aquifers can be recharged from rain water, river water, recycled water, etc.

Groundwater is one of our most valuable resources. Aquifers are nature’s storage tanks provided to mankind. We see a lot of river water being discharged to sea, during every monsoon, without being used. If the rain water & river water are effectively used for recharging aquifers, the ground water availability can be enhanced and Aquifer stored water recovered can be used to alleviate the water shortage.