Artificial Groundwater Recharge Methods in Lalitpur Metropolitan City, Nepal
Groundwater has been used from past centuries to fulfill the water demand of people in the valley. However, at the present scenario, groundwater extraction has moved beyond ground’s natural recharge capacity which has caused depletion of groundwater level. As people are being aware about this issue, they don’t have enough open space to let monsoon water percolate inside the earth. So, they have started artificial groundwater recharge methods in the dense settlement areas of Lalitpur Metropolitan City (LMC). Key Informant Interviews (KIIs) and a survey were deployed to collect information about the artificial groundwater recharge systems being practiced in LMC. In the similar way, recharge methods being employed were compared with a manual developed by CSE, India for recharging groundwater. According to the study, different agencies have been involved in artificial groundwater recharge. They are using seven types of recharge methods altogether. However, all of these methods have used well shaped structure to infiltrate water to shallow aquifer. Beside recharge well, they have used almost common types of filter material with different proportion to separate sediment load from runoff water that is supposed to be recharged. likewise, certain recharge methods have sedimentation chamber too. Altogether, three types of catchment areas are used for groundwater recharge and there also exists variation in the catchment area from one method to the next method. Additionally, all of these recharge methods do not have any provision to tackle with water contamination. However, artificial groundwater recharge systems that are being implemented in LMC have some short comings which can be seen during the design and operation phase. So, it will be a great idea for the agencies to develop a proper design for recharge methods which can operate smoothly in the coming days ensuring water quality.