DEEP RECHARGE
Roof top rain water harvesting can also be used to recharge the deeper acquifers. This is done by diverting the rain collected in the roof to the deeper acquifers. are used for the purpose.
Roof-top harvested water can also be ideally diverted to existing wells and hand-pumps especially Old abandoned bore wells, and open wells which source the old acquifers. Since wells and hand-pumps are dug deep and access the aquifers, they make excellent recharging pits. This is especially useful if the well / handpumps are abandoned and not in regular use. These abandoned structures are ideal as we use existing resources and do not have to spend additional funds for putting these in place.
This design is suitable for areas with shallow (5 to 15 m) water level in hard rock as well as soft rock terrain for individual houses, group housing societies, schools and small industrial sheds.
How it works:
Before using the dug well as recharge structure, its bottom should be cleaned and all the fine deposits should be removed.
The recharge water is guided through a pipe to the bottom of well or below the water level to avoid scouring of bottom and entrapment of air bubbles in the aquifer.
Recharge water should be silt free. Hence a sedimentation tank before the water is diverted to the well would be useful. Sedimentation tanks are a simple structure that hold water and allow the sand and mud particles to settle down.
The top part of the tank is connected to the well.
Periodic chlorination should be done for controlling the bacteriological contaminations.
