Urbanization impact on hydrogeological regime in Jaipur Urban Block: a rapidly growing urban center in NW India

A sharp decline in the water level in Jaipur city and its hinterland region in NW India has been observed during the last decades. Such a drop can be correlated with a widening gap between groundwater draft and recharge resulting from poor and erratic rainfall and over-exploitation of groundwater resources. The city has undergone uncontrolled urban expansion complete with a multifold rise in the population, which now stands at more than 3.3 million. Drying up of the surface water bodies has further led to a total dependence on groundwater resources to meet the rising domestic and industrial demand for water. There are about 1,000 bore wells drilled by Governmental agencies and an estimated 11,000 privately owned ones. The water is generally alkaline carbonate–bicarbonate type. We evaluated water quality for the period between 1993 and 2001 and observed notable deterioration that we attribute to inadequate recharge and a change in the potential water-bearing zones from alluvium to granite–gneiss bedrocks, caused by a drop in the water table. In addition, we also attribute the problem of high nitrate in groundwater in densely populated parts of Jaipur city to improper sewage disposal.