‘More groundwater used than recharged’

Delhi extracted more groundwater in 2024 than it recharged, reversing a two-year trend of sustainable usage, according to the latest Central Groundwater Board (CGWB) report released in December 2024. The capital recharged 0.34 billion cubic metres (bcm) of groundwater (34,190.47 cubic hectare metres or ham) during the year but extracted 34,453.58 ham, making the extraction rate 100.77%. 

This marked a shift from the extraction rates of 99.13% in 2022-23 and 98.16% in 2021-22. Extraction rates above 100% indicate more water is being drawn than replenished, worsening groundwater depletion, the report said. The rate was 101.4% in 2020-21 and a concerning 119.6% in 2017-18, officials said. 

The CGWB report categorised Delhi’s 34 tehsils into four groundwater safety classifications. Fourteen (41.18%) were deemed “over-exploited,” 13 (38.24%) as “critical,” two (5.88%) as “semi-critical,” and only five (14.71%) as “safe.” In safe zones, recharge exceeds extraction, allowing the water table to rise by up to 2 metres annually. Semi-critical and critical zones see 70-100% extraction, while over-exploited zones exceed 100%, causing the water table to fall, the report mentioned. 

According to the report, over-exploited areas include Shahdara, Mehrauli, Kapashera, Rajouri Garden, Vasant Vihar, Narela, Karol Bagh, and Mayur Vihar. Notably, the number of over-exploited tehsils fell to 13 in 2023 from 15 in 2022. 

Residential use accounted for most of the groundwater extraction (0.26bcm), while irrigation accounted for 0.08bcm. The report attributed the marginal increase in extraction to urban expansion and unauthorised colonies. “When the city is expanding, there will be areas or unauthorised colonies where water is not initially available, and so groundwater extraction is the only reason to get water,” said Shashank Shekhar, assistant professor, Department of Geology, Delhi University. He added, “Long-term, we are still seeing an improvement, though as Delhi’s piped water supply is expanding rapidly.”