Field evaluation of abandoned open well for recharging surplus canal water

Abstract

Groundwater plays an important role in fulfilling everincreasing demand for water by agricultural, industrial and domestic sectors. Due to its availability at the point of use, farmers prefer groundwater for irrigation, which results in over-exploitation of groundwater resources. Analysis made for Punjab’s 138 blocks till 2017 has revealed that only 22 blocks were in safer zone (CGWB 2018).Study by (Brar et al. 2016) shows that from 1998 to 2015, area having water table depth greater than 10 m in Punjab has increased from 20 to 69 %so to overcome this problem recharge of groundwater is one of the important viable solution which draw our attention on artificial groundwater recharge.The declining trend of groundwater can only be arrested by augmenting and using it judiciously. Groundwater augmentation is a process of replenishing aquifer by adding excess water (available from canals, storm water or rainwater harvesting (rooftop or surface)) with the assistance of some structure like abandoned well, ponds, pits and injection wells after proper filtration.In Punjab there are at least 1.45 lakhs of abandoned wells present which can be used for recharging purpose (Anon 2003). Emily et al. (2016) study shows that the dry wells can be used for aquifer recharge.So, In the present study, field evaluation of groundwater recharge through abandoned well using canal water under constant head conditions in an unconfined aquifer was performed. During 24 days recharging operation, net2000m3 of canal water was stored in the water table aquifer. However, the recharging rate was decreased from 4.2 to 2.7 l/s during complete operation. Reduction in rate of recharge was mainly due to increase in total suspended solids (TSS) of canal water.