Rethinking Gurugram’s waterlogging fix: Let the city absorb, not divert
Gurugram experienced two bouts of heavy rainfall this year — the first between July 9 and 10, when about 133 mm of rain fell within 12 hours, and the second on September 1, which saw over 100 mm of rainfall in just four hours. Both downpours led to severe waterlogging, power outages, and hours-long traffic jams stretching for kilometers along major highways such as NH-48, prompting authorities to issue work-from-home advisories.
Public frustration quickly spilled onto social media, with countless posts blaming the government for the city’s poor infrastructure. In October, Union Minister for Power, Housing and Urban Affairs, M L Khattar, directed the Gurugram Metropolitan Development Authority (GMDA) and the Irrigation Department to plan a new stormwater drain from Gurugram to Palwal via Sohna and Nuh. The proposed project aims to channel excess rainwater from Gurugram into the Yamuna river near Palwal, thereby addressing the city’s persistent monsoon waterlogging issues.
Experts, however, have voiced serious doubts about the project’s feasibility. They point out that Gurugram’s natural drainage system flows northwest toward the Najafgarh Jheel and the Sahibi river (Najafgarh Drain), and that diverting this flow southward against the natural gradient would necessitate massive pumping, making the project both economically unviable and environmentally damaging.
Assessment of Gurugram’s topography reveals that a natural ridge formed by the Aravalli hills runs through the district, creating a clear drainage divide that defines the city’s hydrology. Historically, runoff from the Aravalli slopes and adjoining urban areas has drained northwest into the Najafgarh Jheel and Sahibi river, which eventually joins the Yamuna in Delhi. This basin has functioned as a vital natural stormwater reservoir, absorbing seasonal rainfall from Gurugram and its surrounding catchments.
Government and technical studies further note an elevation difference of roughly 60-80 meters between the Aravalli foothills and the Najafgarh Jheel. This natural gradient reinforces Gurugram’s north-westerly drainage pattern and explains why any attempt to divert runoff southward towards Palwal and ultimately the Yamuna basin would entail major infrastructural interventions and large-scale pumping operations.
Given that the proposed alignment of the project extends from Gurugram to Palwal via Sohna and Nuh, and that a detailed project report (DPR) is yet to be prepared, a preliminary, back-of-the-envelope assessment was undertaken to gauge its feasibility. For this purpose, the area under the Gurugram Municipal Corporation (GMC) was considered to estimate stormwater runoff under different monsoon rainfall scenarios.
According to a study based on Sentinel-2 data of 2022, the Gurugram Municipal Corporation (GMC) area covered a total of 306.9 sq km (excluding water bodies), comprising 203.5 sq km of built-up land and 103.4 sq km of non-built-up area, which includes trees, bare ground, rangeland, and cropland. For runoff estimation, runoff coefficients of 0.8 for built-up areas and 0.2 for open areas were assumed.
To evaluate potential runoff volumes, three rainfall scenarios—50 mm/day, 100 mm/day, and 160 mm/day—were analysed, representing moderate, heavy, and very heavy rainfall events, respectively. These scenarios reflect recent climatic patterns — Gurugram recorded two single-day rainfall events exceeding 100 mm this year, and with climate change projected to increase the frequency of high-intensity, short-duration rainfall, such extreme events are expected to become more frequent in the future.
Based on the above assumptions, the estimated runoff generation from the GMC area is approximately 9 million cubic metres (MCM) per day for 50 mm/day rainfall, 18 MCM per day for 100 mm/day, and about 29 MCM per day for 160 mm/day rainfall. Experts have observed that the proposed stormwater drain’s alignment would run counter to the natural drainage gradient, necessitating a deep drain at a depth of approximately 18 metres to cut through the ridge in the initial stretches. At this depth, the drain’s cross-sectional area is estimated to be around 12 square metres, with a natural flow velocity of about 1 metre per second. Under these conditions, the drain’s discharge capacity would be approximately 12 cubic metres per second.
If pumping mechanisms were introduced to double the discharge rate, the flow could potentially reach 24 cubic metres per second, translating to a total discharge volume of about 2 MCM per day. Achieving such capacity, however, would demand substantial energy inputs, complex engineering, and extensive infrastructure investment, making the project highly resource-intensive and costly. According to expert estimates, the overall project cost—including land acquisition—is expected to be around Rs 1,500 crore.
While the discharge capacity of the proposed drain has been estimated, actual on-site conditions may result in a considerably lower capacity due to a smaller effective cross-sectional area or reduced flow velocity.
After estimating the runoff volumes generated under various rainfall scenarios and the discharge capacity of the proposed drain, along with the substantial energy inputs and infrastructure costs involved, the feasibility of the project appears questionable.
First, even with heavy pumping, the proposed stormwater drain has a maximum discharge capacity of approximately 2 MCM per day. This capacity is inadequate to manage the 9 MCM of runoff generated by a 50 mm/day rainfall event—let alone the 18 MCM and 29 MCM expected under 100 mm/day and 160 mm/day rainfall scenarios, respectively. Such volumes would easily overwhelm the proposed drain, rendering it ineffective. Moreover, this assessment is based on daily capacity; when shorter, more intense rainfall events are considered, the situation becomes even more critical. For instance, between July 9-10 this year, 133 mm of rainfall occurred within just half a day, and over 100 mm fell in only four hours on September 1. Under such conditions, the drain’s effective capacity would be merely 1 MCM in 12 hours and just 0.33 MCM in four hours—far below the required capacity to handle these extreme events.
Second, the project cost estimated by experts—including land acquisition—cannot be justified for a system that would operate at full capacity only during 3-4 heavy rainfall events, amounting to roughly 10 days in a year. For the remainder of the year, the drain would remain unutilised, particularly the heavy pumping infrastructure, which would be prone to disrepair and may not function effectively when required during those few monsoon days.
Third, Gurugram already possesses a natural stormwater reservoir in the form of the Najafgarh Jheel wetland, the natural drainage sink toward which most of the city’s runoff flows. On the Haryana side, the Jheel has a storage capacity of around 32 MCM, and at the 211-metre contour, it spans over 5,000 acres. This wetland can effectively store runoff from even the heaviest rainfall events, providing not only waterlogging mitigation during the monsoon but also a valuable water resource for groundwater recharge and use during the dry season.
Fourth, Gurugram has been declared a ‘dark zone’ by the Central Ground Water Authority (CGWA) due to over-extraction of groundwater. In 2024, the city drew 212 per cent of its permissible annual groundwater limit, more than double the sustainable threshold, as reported in the National Compilation on Dynamic Groundwater Resources of India. This over-extraction threatens agricultural productivity, health of waterbodies, and is already contributing to land subsidence—with structural damage being reported in parts of the city. In this context, the proposal to divert stormwater out of the city towards Palwal, rather than using it to recharge local aquifers, reflects a troubling lack of foresight.
Finally, Gurugram’s real challenge lies not in where its stormwater drains, but how it drains. The city’s inadequate internal drainage system prevents effective runoff dispersion, causing waterlogging during even moderate rainfall. A more sustainable approach would focus on strengthening local drainage networks, creating distributed storage systems, enhancing soil permeability, and integrating pumping and recharge infrastructure—turning stormwater from a liability into a resource.
The analysis above clearly indicates that the proposed project would be a white elephant. To truly improve Gurugram’s drainage and waterlogging resilience, the city must adopt low impact development (LID) strategies that work with nature rather than against it. Measures such as retention ponds, rain gardens, bioswales, permeable pavements and parking lots, green roofs, and infiltration trenches can help capture, store, and absorb stormwater where it falls. Complementing these with the revival of traditional water bodies, wetlands, and ponds across the city will make Gurugram far more permeable and climate-resilient. This nature-based approach not only mitigates local waterlogging but also advances progress toward Sustainable Development Goals (SDGs) 11 and 13—fostering inclusive, safe, resilient, and sustainable cities while promoting urgent action against climate change and its impacts.
Instead of diverting monsoon stormwater outside the city, Gurugram must learn to absorb and manage it within its boundaries, allowing excess runoff to flow naturally into the Najafgarh Jheel wetland. This wetland can act as a buffer and storage basin, recharging groundwater and gradually releasing surplus water into the Yamuna in Delhi. By embracing such nature-based, sustainable solutions, Gurugram can transform its waterlogging problem into an opportunity for water security and ecological restoration.
Ritu Rao works with Indian National Trust for Art and Cultural Heritage (INTACH) on various natural heritage projects
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth