Urban Floods: Growing Menace in Cities

Humans have begun witnessing the effects of climate change in the form of rising annual mean temperature, rising sea level, sporadic monsoon, and increased frequency of cyclones. Cities in India have also begun to feel the effects of climate change in various forms and one of them is urban flood. According to the data of National Disaster Management Authority (NDMA), the incidences of urban floods is on the rise in India. Floods in Hyderabad happened to be the first recorded event of urban floods in the country. Later, Ahmedabad (2001), Delhi (2002, 2003, 2009 & 2010), Chennai (2004), Mumbai (2005), Surat (2006), Kolkata (2007) Jamshedpur (2008) and Guwahati (2010) have also had the misfortune of encountering urban floods

Urban floods have emerged as a major issue in cities, especially in India, and encroachment of drainage infrastructure in cities has been one of an important catalytic factors. In order to combat and minimise the effects of urban floods on Indian cities, various departments and organisations such as the National Green Tribunal (NGT), NDMA, and the Ministry of Housing and Urban Affairs (MoHUA), have prepared their own set of guidelines. However, the primary focus will be on guidelines of MoHUA and how Indian cities are adhering to these guidelines.

What are the prescribed guidelines?

MoHUA has prescribed a set of guidelines, to prevent Indian cities from coming to a standstill and preventing the loss of life and damage to property. These guidelines are called the Manual for the stormwater drainage system, prepared by the Central Public Health and Environmental Engineering Organisation (CPHEEO) in 2019.
These guidelines highlight that all the storm drains should be inspected frequently to identify any blockage or damages to the drains in India. It recommends thorough examination of scouring of bed and sides, blockage of the drains due to garbage dumping, damage to the structures, and keen inspection of junction sump and gutters. Additionally, walking inspections should also be done regularly, especially before the onset of monsoon, and the interval between such inspections must not exceed one month.
It also made a recommendation regarding the maintenance of the storm drains. All the drains must be desilted, all the damages should be repaired, and the garbage such as polyethene which could block the flow of water must be removed before the onset of monsoon.
In addition, condition of road cambers needs to be inspected after every heavy shower to inspect any potential damage and essential corrective measures should be taken immediately following the rain. To prevent any accidents, all the missing and corroded slabs and caps of the gutters should be replaced if necessary.
One of the most essential aspects of these guidelines is creating awareness among citizens, in order to dissuade them from dumping garbage and other materials that could block the passage of water and encroaching or building any pavements over these drains. States however could take any additional steps along with these recommendations.

How our cities have been faring?

As far as the National Capital Territory of Delhi is concerned, the NGT itself has established an Integrated Drain Management Cell (IDMC), to look after the remediation and management of networks of drains in Delhi. Apart from that, Public Works Department (PWD) manages nearly 2064 km, while rest of the drains in the capital are managed by the Municipal Corporation and Delhi Jal Board.
The drains that are maintained by the PWD are desilted once a year before the monsoon arrives in the city, while those maintained by the civic bodies are desilted twice a year. The local bodies in Delhi have taken several initiatives to solve the problem of water logging in the capital. For instance, for the management of excess water around the Minto Bridge underpass area, four CCTV cameras and sensors have been installed by the PWD that are connected to 12 pumps around it. When the water reaches a certain level, the alarm goes on, and the pump begins to throw water out of the underpass in order to avoid water logging and flooding during Monsoon.
One of the major challenges faced by Indian cities, especially Delhi, regarding the maintenance of storm drains is the problem of choking of drains, which leads to water logging on the roads. In areas around Ghazipur Mandi and Azadpur Mandi, one can see heaps of garbage piled up on the roads, while some of the garbage such as plastic bags, bottles, cans, and construction and demolition waste is directly dumped in the drains.
Chennai also had a catastrophic encounter with urban floods in the year 2015. The city has also been taking measures to prepare for any contingency situation. The Government of Tamil Nadu had established the Thiruppugazh Panel in November 2021, to prepare area-specific stormwater drainage plans and devise long-term plans for the basin area of Kancheepuram, Thiruvallur, Chengalpattu, and Ranipet.
Earlier, in October 2021, the Government of India signed a pact with the Asian Development Bank (ADB) for the planning and implementation of Integrated Urban Flood Management in Chennai. Under this pact, the ADB will provide assistance in the creation of urban flood protection infrastructure. The pact includes the construction of 588 kilometres long new storm drains, replacement of 175-kilometre-long old drains and enhancing the water carrying capacity of the channels in Ambattur, Ariyallur, Kadapakkam, and Korattur.

Does this solve the problem of urban floods?

Although states and civic bodies seem to have been implementing these guidelines of MoHUA, the compliance is neither complete nor efficient. Waterlogging on the roads after even moderate rainfall is a common sight. It is, in itself, enough evidence of the effectiveness of the implementing agencies. A majority of cities in India are primarily focusing on the development of new drains and flood management infrastructure, while neglecting the maintenance of the existing ones.
It’s not that making new drains and adopting innovative technological solutions should be cast aside. These could solve the problem of waterlogging in the cities of the future, but the maintenance of the existing drainage system must not be neglected either.
Apart from that, whenever a drain or a gutter is cleaned, the extracted material is dumped just beside the drain from where it again makes its way back to where it was extracted from.
The burden of waterlogging and urban floods cannot be completely shifted onto the shoulders of the administration. People themselves are equally responsible for the situation. A majority of shopkeepers in cities throw dust cleaned from their shops right on top of the side drains, where they haven’t already been encroached upon.
Even though the civic bodies in the majority of our cities collect garbage directly from the houses even then you could easily locate the garbage bags lying on the roadside or flowing down in the local ‘nallahs’. All the awareness campaigns unleashed by the central government, state government and the local bodies haven’t been able to bring much behavioural change.
Therefore, compliance with these guidelines has to come from both the administration as well as from the people, if we as a country want to make the incidence of urban floods and water logging a thing of the past. Thus, making our cities disaster resilient.

For the management of excess water around the Minto Bridge underpass area, four CCTV cameras and sensors have been installed by the PWD that are connected to 12 pumps around it. When the water reaches a certain level, the alarm goes on, and the pump begins to throw water out of the underpass in order to avoid water logging and flooding during Monsoon