Often groundwater pumping is undertaken assuming the resource to be infinite. This myth has been shattered in the last few decades with increasing scarcity and deterioration in terms of quality as a consequence of over-exploitation and mismanagement of this resource to meet competing demands for drinking water and other needs in urban cities. However, managing groundwater is not an easy task. This is simply because a groundwater molecule underground is always in motion but never visible in situ. This inherent dynamic and hidden nature of ground water in terms of quality and quantity makes it difficult to manage groundwater resources. It is important to note that surface and groundwater are the same resource appearing in one or the other form based on hydrogeology. Thus the dimensions of the complex problem ranges from hydrogeology to policy/ regulatory and politico-socio-economic factors. For effective management following aspects are important and must be sequentially implemented:
- Development of Database of spatial and temporal data relating to hydro-geology and hydrology
- Mapping the hydrogeology in 3D space using GIS
- Monitoring and mapping of historical Ground Water data: levels; salinity and other quality parameters
- Identification of recharge and discharging areas (this includes existing rainwater harvesting structures), water logged areas, existing wells etc.
- Development of a 3D Ground Water model for the whole city and adjacent with appropriate boundary conditions and aquifer properties
- Simulation and calibration of groundwater model in terms of levels and quality (salinity) using historical data
- Analysis of the results of the model and development of prediction scenarios for the projected planning period
- Policy formulation and evaluation and legislation for GW wells (domestic and public), rainwater harvesting structures and other water structures that interact with groundwater. The policy must be politico-socio-economically feasible.
- Policy implementation/ regulation and post audit systems
Therefore the need is to develop Groundwater models for each city/ urban cetres and study the discharge/ recharge processes before arriving at any policy for longterm groundwater management and regulation on a sustainable basis both in terms of quality and quantity.