Study on sustainable development and management of groundwater at dohnavur fellowship area in naguneri taluk, tirunelveli district, tamilnadu

There was a mounting concern on providing adequate water for Dohnavur Fellowship to support its orphanage, school and hospital, targeting 1500 inhabitants. Groundwater is the primary source of water for drinking, domestic and agriculture at the Dohnavur fellowship that covers 350 acres of land. The project area lies at the latitude of 8o27’N and longitude of 77o35’E in Nanguneri taluk of Tirunelvelli district in Tamil Nadu. The average annual precipitation is 840 mm. The Terrain comes in the catchment area of Nambiyar river basin, underlain by crystalline rock formation, consisting of the Archaean age of Gneisses, covered with Kankar formation. The whole area depends solely on ground water, extracted through open well and bore wells. Most of the open wells are abandoned due to increased number of bore wells in their surroundings. Increasing withdrawal of groundwater from neighborhoods and erratic monsoon resulted in lowering the water table in the fellowship area. The water level varies from 18 m to 21m at pre-monsoon period and 4 to 5 m depth at post-monsoon period. The Fellowship was struggling to provide water to its 750 school students, 500 orphans and about 200 patients in their hospital. The agricultural activities in 100 acre of land also started suffering water scarcity. Electrical resistivity survey was carried out (profiling and VES) to identify the potential zones based on which the recharge and discharge zones are identified. The thickness of layers and fractured pattern were identified. Based on all these findings, different artificial recharge measures are proposed with appropriate design. The water extraction and usage method have been modified and recharge measures are adopted in the entire campus area. All the bore wells and open wells are supported with appropriate recharge measures. Three of the abandoned open well has been converted into recharging wells. To reduce the overall water requirement of agriculture organic farming is adopted. Drip irrigation is being followed for plantation crops. Presently, System of Rice Intensification is being practiced to further reduce the irrigation requirement. As a result of minimizing water requirement, judicial extraction and maximization of recharging, the sustainability of groundwater is maintained.