Studies on Borewell Recharge through Filter Bed using Runoff Water in Eastern Dry Zone of Karnataka

Recharge of defunct borewells through filter bed was studied for 4 years from 2011–12 to 2014–15 at 3 locations using five defunct borewells with base line discharge ranged between 0 and 126.6 lpm at UAS, GKVK, Bengaluru and Hosapalya village, Nelamangala Taluk, Bengaluru rural district, Karnataka. The discharge rate at 15 days interval after the treatment was recorded. The results showed that over the study period of 4 years, the average discharge rate of borewells 1 to 4 with filter bed treatment was higher in rainy season but lower in summer season and vice-versa (46.8 and 138.0 lpm, respectively) in case of borewell-5. The physico-chemical component values of recharge water of borewells with filter bed recharge system of pH ranged between 8.59 and 7.44, conductivity between 31.00 and 858.00 μs/cm, chloride 63.9–92.3 mg/l, sodium absorption ratio 5.59–10.70, sulphate 124.8–172.8 mg/l and residual sodium carbonate between 0.16 and 1.44 mg/l showing suitability for drinking purpose.