There has been a sharp decline in groundwater levels in several parts of Delhi, West Uttar Pradesh, Haryana and Rajasthan over the years, the government said on Friday.

According to the data released here, which is part of country’s first ever aquifer atlas, Himachal Pradesh has the best groundwater level as water exploited is quickly recharged. The atlas, first ever compilation of aquifer systems in India, says that within the national capital, southwest Delhi is the worst affected by depleting groundwater levels.