Rainwater Harvesting for Groundwater Recharge: Experience From Sri Lanka

Almost 80% of the rural populations in Sri Lanka rely on groundwater for their domestic needs. Shallow wells are prone to be affected by climate changeClimate change. During the monsoon season, the water levels of the shallow wells generally rise near the ground surface as recharge to the aquiferAquifers takes place. During dry season, groundwater level goes down due to abstraction, evapotranspiration, and other losses such as seepage and percolation. The quality of groundwater has deteriorated over the years due to various anthropologic activities. Necessary steps need to be taken so that the water levels in the well rise and also to improve the quality. Rainwater harvestingRainwater harvesting is an age-old practice, which is revived to ease domestic water supply in water-scares areas. Lanka Rain Water HarvestingRain water harvesting Forum conducted three studies in different agro-ecological zones of Sri Lanka to monitor the effectiveness of different types of groundwater recharging structures. The traditional groundwater recharge structures such as the garden pond (Pathaha) as well as runoff tanks play effective roles in maintaining the water levels in the nearby wells. Rainwater harvested from the roof and directly put into the well is found to have a higher recharging effect than the rainwater harvestingRainwater harvesting tank. Improvement of groundwater quality is also recorded in wells near the recharge structures.