Rooftop rainwater recharge
Pipe roof water through a silt trap and filter into a recharge pit or an old borewell. Every 100 m² of roof puts back tens of thousands of litres a year, right where the pumping happens.
Groundwater use is within safe limits here. That is the 2025 stage of groundwater extraction: water pumped out in a year as a share of what rain and other sources safely put back. Up 9 points since 2017.
Each point is one CGWB assessment. Over-exploited means more water leaves the ground than comes back, so the water table keeps falling. Hover over or tap a point to see why it moved.
| Year | Stage | Pumped out | Safe limit | Category | What changed |
|---|---|---|---|---|---|
| 2009 | 7.0% | 52.8 million m³ | 746 million m³ | Safe | First assessment in this series. |
| 2013 | 9.0% | 68.6 million m³ | 727 million m³ | Safe | Pumping up 30% (53 → 69 million m³). Safe limit down 3% (746 → 727 million m³). |
| 2017 | 9.0% | – | – | Safe | CGWB changed its method in 2017 (GEC-97 to GEC-2015), so part of this change comes from the new method. |
| 2020 | 9.4% | 68.6 million m³ | 727 million m³ | Safe | Little change since 2017 (+0.4 points). |
| 2022 | 15.0% | 91.4 million m³ | 610 million m³ | Safe | Pumping up 33% (69 → 91 million m³). Safe limit down 16% (727 → 610 million m³). Main reason: more water was pumped out, mostly for homes and industry (46 → 71 million m³). A swing this large usually comes partly from revised estimates (a new well count or changed district boundaries), not only from changes on the ground. |
| 2023 | 17.3% | 92.5 million m³ | 536 million m³ | Safe | Pumping up 1% (91 → 93 million m³). Safe limit down 12% (610 → 536 million m³). |
| 2024 | 17.7% | 93.7 million m³ | 529 million m³ | Safe | Pumping up 1% (93 → 94 million m³). Safe limit down 1% (536 → 529 million m³). |
| 2025 | 17.8% | 94.6 million m³ | 531 million m³ | Safe | Pumping up 1% (94 → 95 million m³). Safe limit up 1% (529 → 531 million m³). |
Million m³: 1 million m³ = 100 crore litres. 2009 and 2013 used the older GEC-97 method.
Loading 20 years of rainfall…
2,031 of 20,867 water bodies (10%) are not in use: dried up, silted, built over or polluted. Bringing them back is one of the cheapest ways to recharge groundwater.
Loading the map of water bodies in Puruliya…
Source: 1st Census of Water Bodies, Ministry of Jal Shakti (counted in 2018-19, published 2023).
Groundwater here is in balance. Keeping it that way means recharging as the area builds up and paves over.
Pipe roof water through a silt trap and filter into a recharge pit or an old borewell. Every 100 m² of roof puts back tens of thousands of litres a year, right where the pumping happens.
Treated water from a sewage treatment plant can run flushing, gardens, cooling towers and construction, which today often draw on borewells.
Parks, campuses, warehouse yards and road sides can take recharge shafts that reach past the clay layer, so runoff that floods streets goes down to the aquifer instead.
Metered and registered borewells, leak repairs in supply lines and water-efficient fixtures cut pumping without anyone going short.
Desilting old ponds and opening their feeder channels restores natural recharge. A one-hectare pond that soaks in a metre of water over the monsoon puts back about a crore litres.
Porous pavers, unpaved tree pits and bioswales along roads let rain soak in instead of racing to the drain.
In the 2025 Central Ground Water Board assessment, Puruliya (West Bengal) pumped out 18% of the groundwater that can be safely taken out each year, which puts it in the "safe" category. That is 9 points higher than in 2017.
No. At 18% of the safe yield, Puruliya is safe, though recharge is still needed as demand grows.
Rooftop rainwater harvesting into recharge pits or old borewells, recharge shafts in open land, reviving ponds, check dams, treating and reusing wastewater, and moving farms to drip irrigation and less thirsty crops.
The first Census of Water Bodies counted 20,867 water bodies in Puruliya, including 20,395 ponds. 2,031 of them were not in use.
Yearly rain at Puruliya, 2006–2025, from NASA satellite data. Lighter bars are dry years (20% or more below average), when wells are drawn hardest.