Ground water year book – India 2017-18
The ground water is a replenishable and dynamic resource in nature. For assessing its availability over time and space and ensuing sustainability of the development programs , it becomes essential to continuously or periodically monitor the ground water regime and quality. It is an effort to obtain information on ground water levels through representative monitoring wells located in different hydrogeological environments. The important attributes of ground water regime monitoring are water level and water quality. The natural conditions affecting the regime involve various hydrometeoroical parameters like rainfall, evapotranspiration, runoff, etc., whereas anthropogenic influences include pumpage from the aquifer, recharge due to irrigation systems and other practices like water conservation structures etc. The Board is monitoring the water level in the country through a network of 23,196 monitoring stations (National Hydrograph Monitoring Stations) out of which, 6,503 are Dug wells and 16,693 are Piezometers, four times a year i.e., January, March/April / May, August and November. The Ground water samples are collected from these monitoring stations once a year during the month of March/April/ May to obtain information on changes in chemical quality of ground water. The database thus generated forms the basis for planning the ground water development and management programs like NAQUIM, Artificial Recharge, Ground Water Resource Estimation . The ground water level and quality monitoring is of particular importance in coastal as well inland saline environment to assess the changes in salt water/fresh water interface as also the gradual quality changes in the fresh ground water regime.