Development imperatives of Delhi dealt with the construction of buildings & other infrastructures; protection of stormwater drains in their pristine character had no place in the euphoria of a newly born country
The town planners failed to consider the contours of the land, leading to waterlogging as a natural outcome of such a lack of foresight. Photo: Vikas Choudhary / CSE. One torrential monsoon shower and Delhi has flooded again!! Citizens erupt in a mix of anguish and anger as roads, homes, basements, offices, rail tracks and underpasses all become waiting spaces for run-off rainwater.
Electricity disappears, transportation goes static, municipal corporation helplines die out or remain unanswered and gangs of ‘political social workers’ melt into the darkness of apathy.
For the few days in the year that Delhi faces its ephemeral monsoon deluge, print tableaus grab eyeballs with catchy photos and screechy headlines, and fiery TV debates engage in mudslinging.
Still, predictably no solutions emerge to Delhi’s perennial flooding conundrum. Once the floodwaters abate, true to our resilient nature, we return to our daily lives; memory does not do us proud.
The imperial city of Delhi has been home to rajas, badshahs, viceroys, governors, and rashtrapatis; a beautiful city located on the banks of the river Yamuna. Situated in a cup-shaped valley of the foothills of the Aravalli Mountain Range, rivulets and tributaries originating in the undulating foothills meandered through the plains of Delhi, feeding into the river Yamuna.
These tributaries, besides carrying fresh water from the Aravallis, during monsoons, performed the role of stormwater drains, swiftly draining Delhi dry within a few hours of heavy rainfall.
However, this changed once Delhi became independent India’s capital. During its nascent years of independence, Delhi grew haphazardly with the influx of refugees from partitioned India and increased workforce requirements for building the capital city.
Alarmed at the chaotic growth of Delhi, the Centre promulgated the Delhi Development Act in 1957 for the systematic development of Delhi.
The development imperatives of Delhi dealt with the construction of buildings and above-ground infrastructure, neglecting the protection of stormwater drains in their pristine character as tributaries had no place in the euphoria of a newly born country.
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With no sewage system servicing the informal settlements and the walled city of old Delhi, sewage and septage were drained directly into the stormwater drains.
Over time, instead of conveying fresh water from the hills or rainwater after monsoon showers, the beautiful tributaries of Yamuna flowing through Delhi came to be treated as ganda nullahs, contaminating not just the storm drains but also polluting the river Yamuna where they eventually drained into.
With the passage of time and increasing anthropogenic pressure on land, public authorities declared they needed ‘more land’ for parking and marketplaces, leading them to cover storm drains with concrete structures.
In the frenzy of covering drains, the Kushak Drain in Defence Colony was also entombed in a monstrous concrete structure, cheered on by the naysayers to prevent foul odours. No environmental studies were undertaken, no detailed project report was prepared, and the slapdash structure was raised over the beautiful drain.
This grave anomaly was brought to the attention of the National Green Tribunal (NGT) by the late river activist and forest conservationist Manoj Misra. Recognising this as a valid concern that affected Delhi’s environment, the NGT directed to maintain the status quo and prohibited further construction on the storm drain.
The judgment aptly recorded the main reason for the frequent flooding in Delhi, stating that many of the stormwater drains, which at one time acted as the natural tributaries of the river Yamuna, had been converted into storm-cum-wastewater drains or covered and obstructed from playing their natural role. This ill-advised conversion has reduced efficient drainage in the city and compromised the biodiversity along these drains.
According to the last Drainage Master Plan of Delhi in 1976, Delhi had 201 tributaries/stormwater drains. However, around 19 of the 201 natural drains could not be traced as they were either encroached upon, blocked with waste, or disappearing. Due to their degraded condition, the ability to rapidly evacuate large volumes of torrential showers has been vastly reduced, leading to flooding, waterlogging and submergence of the city.
The management of surface run-off water is the primary starting point of a drainage system in a city. A dendritic drainage pattern, resembling the branching pattern of tree roots or leaf veins, is the most common. Such drainage channels, called bioswales, develop where surface run-off is enhanced and earth materials provide the least resistance to erosion, with no apparent control over the direction.
Bioswales act as above-ground drainage systems, absorbing part of the water that runs through its channel, which prevents waterlogging. They lead the water directly to larger surface water-carrying channels and are not connected to sewers but to larger water-conveying channels.
Delhi’s urban planning is completely against nature’s systems. Town planning has been done either in a radial pattern (Lutyens Delhi) or the block pattern (New Delhi). However, water neither follows radials nor blocks but flows along the contours of the earth.
The town planners failed to consider the contours of the land, leading to waterlogging as a natural outcome of such a lack of foresight. Open drains were provided in front of houses in the belief that they would drain surface water, but they soon became non-functional, filled with detritus, encroached upon and turned into cesspools of stagnant wastewater.
Hence, it is imperative to nurture bioswales, subsidiary drains, master drains, and stormwater drains. Master drains lead into stormwater drains, and their capacity should be improved by keeping them free of solid waste, detritus, and construction debris.
Stormwater drains, which once had their own floodplains, have been encroached upon and reduced in capacity due to the pressure on land and the dumping of debris. This narrowing down of storm drains prevents the drainage of rainwater from adjacent areas, causing flooding of urban areas.
The rapid concretisation of the city is perhaps the most important factor leading to the submergence of the city during flash torrential rains. Water first percolates the soil, but with concrete or tarmac surfaces, it flows to low-lying areas, including basements, internal roads and depressions. The government and its instrumentalities are culpable for eyeing every vacant land parcel and imposing construction on it, exacerbating the problem.
Delhi’s barren and degraded areas, such as those contiguous to roads, also contribute to rainwater accumulation as they do not absorb rainwater. Vegetated areas, parks, grasslands and urban forests have been proven to accumulate and store water compared to areas devoid of vegetation. The Delhi Ridge, known as the water reservoir of Delhi, exemplifies this.
The final question emerges: who will take responsibility? With a lack of a central authority for storm drains, the coordination between various public authorities, the state and central government and political entities seems like a herculean task. Environmental activists have been tossed from tribunals to courts to committees without relief. It appears that Delhi will continue to face monsoons without a long-term solution in sight.
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth
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