In September 2025, the city of Gurugram in Haryana ground to a halt when 100 mm of rain fell in just four hours. Vehicles remained stuck in waterlogged lanes while employees waded through high waters to reach their offices. Alarm over the sudden burst of intense rainfall was accompanied by the stark visualisation of this city’s infrastructure flaw: it could not absorb such rainfall.
How is the change in rainfall intensity affecting Gurugram?
The India Meteorological Department recorded 732 mm of rainfall in June, July, August, and September 2025. And this number is set to rise. According to the Council on Energy, Environment and Water’s (CEEW), Climate Resilience Analytics and Visualisation Intelligence System (CRAVIS) — an interactive atlas that records key metrics such as extreme hot days, heavy rainfall events, dry spells, and temperature variability spanning over 40 years of past climate trends and nearly four decades of future projections — Gurugram's total annual rainfall could rise from an average of 580 mm in 2011–2024 to an average of 630–660 mm by mid-century (2031–2050) under a high-emissions scenario (Figure 1).
Figure 1: CRAVIS projection of annual total rainfall in Gurugram — current period (2011–2024) vs. mid-century (2031–2050) under RCP 8.5
Source: CRAVIS
This rise in volume could also be accompanied by a significant shift in intensity. CRAVIS projects that the number of unusually heavy rainy days — the number of days each year when rainfall exceeds the 90th percentile compared to a 1981–2010 baseline — could reach 74–75 days in 2031–2050, against a historical baseline of 37–56. This is a near doubling of high-intensity rainfall events: days when rain falls faster than the ground and drains can absorb it.
*Figure 2: CRAVIS projection of unusually heavy rainy days in Gurugram — current period (2011–2024) vs. mid-century (2031–2050) under RCP 8.5 *
Source: CRAVIS
Cities flood when rain arrives faster than drainage can clear it. As evidenced by the recurrent floods, Gurugram has already crossed that threshold. The consistent increase in high-intensity rainfall events has put the current infrastructure of the city under stress causing catastrophic waterlogging.
Why is Gurugram’s drainage system overwhelmed by high-intensity rainfalls?
As per CEEW analysis of satellite data from Worldcover, between 2015 and 2025, Gurugram’s built-up area (concrete roads, rooftops, and paved surfaces that water cannot sink into) tripled from 128 sq km to 451 sq km due to increasing urbanisation. This expansion came largely at the cost of permeable land: barren or open areas decreased from 353 sq km to just 5.6 sq km, a decline of over 98 per cent. Green cover, which can help absorb rainfall, remained nearly unchanged (around 760–780 sq km), while water bodies increased only marginally to 13.5 sq km, insufficient to offset the scale of urban expansion.
Consequently, a much larger share of rainfall now falls on hard surfaces. Earlier, open land—even when dry—would absorb and slow runoff, giving drainage systems time to cope. Today, that buffer has almost disappeared, increasing the likelihood of rapid surface runoff and urban flooding. The city’s drainage network alone cannot absorb the load of over 700 mm of rainfall falling across 75 days.
Two wetlands illustrate what this looks like on the ground. Ghata Jheel in Ghata Village of Gurugram, which once spanned 370 acres and acted as a detention basin — holding Aravalli runoff before it reached the city's drains — has been reduced to under 50 acres and converted into a dumping ground. Najafgarh Jheel, historically a 300 sq km wetland that absorbed the city's floodwaters, was drained and now hosts large-scale housing. The water these wetlands once held has to go somewhere, it directly flows into drains.
These drains were never rebuilt to handle such a high capacity of water. The Badshahpur drain,the city's primary trunk drain, now operates at roughly one-third of its required capacity of 2,300 cusecs, choked by encroachments, siltation, and solid waste dumped directly into its channels.
How can Gurugram implement effective drainage systems?
Gurugram’s flooding problem is the accumulated result of a decade of land-use decisions that stripped the city of its open land and wetlands. Reversing it will require simultaneous action on the ground, in governance, and in how the city plans its growth:
- Formulate a dedicated city action plan for flood risk management: Effective flood planning depends on granular data. CEEW’s City Action Plans for Flood Risk Management in Thane and NavsariCity used ward-level to develop more precise intensity-duration-frequency (IDF) curves for better assessment of past rainfall trends and estimation of peak flood flow discharge for different time periods, providing a sense of the existing carrying capacity of the drainage system.
- Gurugram Municipal Corporation (GMC) should incorporate sub-daily rainfall analysis into city monsoon planning: The GMC must move beyond long-term averages and integrate recent patterns and short-duration, high-intensity rainfall events that unfold within a few hours, into infrastructure design. Real-time data on sub-daily rainfall, which occurs over intervals shorter than 24 hours, must directly inform drainage design operations and upgradation. For instance, CEEW’s analysis of daily rainfall from 1970 to 2021 in the coastal city of Thane shows that one-hour rainfall now reaches 50 mm once every two years, and ~80 mm per hour once every fifty years. Recently, the Brihanmumbai Municipal Corporation (BMC) announced plans to widen its drains this year so they can handle up to 120 mm of rainfall in an hour.
- GMC should integrate water-sensitive urban design and planning (WSUDP) principles into the city’s master plans and development regulations: This means treating stormwater, groundwater, wastewater, and land-use planning as connected systems. It requires mandating protection of natural water bodies and catchments, incorporating drainage features such as infiltration trenches, bio-retention areas, and retention ponds in zoning norms, and enforcing permeable surfaces and on-site rainwater management in new developments.
Addressing Gurugram’s drainage capacity while keeping an eye on its land use-land change ratio will make the city more robust in staying afloat despite increasing downpours.
Yashi Gupta is an Associate Product Manager and Kartikey Chaturvedi is a Programme Associate at the Council on Energy, Environment and Water (CEEW). Send your comments to yashi.gupta@ceew.in.
