Dark zone areas in Bihar
0 of 37 districts in Bihar pumped out more groundwater than was recharged in 2025 (over-exploited, the "dark zone"). 0 more were critical and 2 semi-critical. Across the state, 46% of the extractable groundwater was used.
Semi-critical districts (2)
Stage of extraction 70–90% in 2025.
What a dark zone means for you
Borewells go deeper every few years and some run dry in summer. New groundwater use for business needs a CGWA NOC with recharge conditions. The fix is to put rain back: at 700 mm of rain a year, a 100 m² house roof recharges about 60,000 litres.
Frequently asked questions
Which areas of Bihar are in the dark zone?
No district of Bihar was over-exploited as a whole in 2025, but 2 were critical or semi-critical, and single blocks can still be over-exploited.
Is Bihar's groundwater over-exploited overall?
The state pumped out 46% of its extractable groundwater in 2025, which CGWB classes as safe.
Can I get a new borewell in a dark zone of Bihar?
Homes usually can, with local registration; some cities restrict new borewells. Industry, infrastructure, mining and commercial users need a Central Ground Water Authority NOC, which in over-exploited areas carries tighter limits and recharge conditions.
Source: CGWB Dynamic Ground Water Resource Assessment 2025, district figures. CGWB classifies blocks (assessment units); a district's figure is the average of its blocks, so a district shown here as safe can still contain over-exploited blocks.