Relief won’t do - Bengaluru needs reform to end flooding

As the ‘May Mayhem’ battered the city —bringing the second-highest rainfall — residents scrambled for safety. Roads, subways, low-lying areas and homes were flooded; lakes and drains overflowed; traffic was thrown into chaos, and mobility was severely disrupted. It is a familiar tale of woe for the citizens of India’s IT capital. And, as always, the blame game continues – government, opposition, and citizens pointing fingers at one another.

Deputy CM and Minister for Bengaluru D K Shivakumar said, “The issues we face today have been ignored for years, across governments and administrations… We are working to solve them — not with temporary fixes, but with long-term, sustainable solutions.” While his assessment is partly true, the solutions proposed so far are not sustainable. In fact, they may prove counterproductive.

With the regular monsoon yet to begin, the immediate challenge is to prepare for further rain-induced disasters. Urban flooding has become a persistent problem across India’s major cities. The causes are well known: unplanned urban growth and the destruction of natural drainage systems, resulting in encroachment on lakes, open spaces, and wetlands.

A study by the National Institute of Urban Affairs reveals that major Indian cities have lost 70-80% of their water bodies, leading to reduced natural water storage, increased surface runoff, and disruption of the natural water cycle. The Intergovernmental Panel on Climate Change notes that rising frequency and intensity of extreme rainfall events in India generate more water than our drainage systems can handle —exacerbated by soil unable to absorb water quickly.

The consequences are severe and widespread: loss of lives and injuries; damage to infrastructure, including roads, buildings, and bridges; displacement of people; disruption of essential services like water supply and electricity; increased exposure to infections affecting humans and animals; and mental stress. Economic activities also take a hit with resultant financial losses.

As the National Disaster Management Authority (NDMA) rightly notes, urban flooding differs significantly from rural flooding. Urbanisation creates impervious catchments that increase flood volumes by up to six times, leading to rapid and intense flooding. In response to increasing urban flood events, the NDMA has issued national guidelines for managing urban flooding. These adopt a holistic approach, emphasising technology for real-time flood monitoring and early warnings, enhancing urban infrastructure, and upgrading drainage systems.

While civic organisations undertake some immediate post-flood relief measures, what is needed is a comprehensive, sustainable plan. For Bengaluru, in particular, the following must be prioritised:

Smart drainage system: Adopt sensor-based drainage technologies to detect water levels, regulate flow in real time, and improve drainage efficiency. Bengaluru’s existing system — comprising rajakaluves, side drains, and shoulder drains below the footpaths — was designed decades ago and is now woefully inadequate for the city’s expanded population and water usage. A redesigned, higher-capacity system is urgently needed. Though expensive, such investment is essential for the city’s future.

Solid waste management: Accumulated waste across the city contributes to flooding by clogging stormwater drains. Most remain choked with garbage and uncleaned debris, forcing rainwater to overflow onto roads and into homes. The BBMP must conduct systematic cleaning of drains and monitor industries and residents who dump waste illegally, imposing heavy penalties where necessary.

Dismal state of roads: Poor quality of roads and recurring potholes worsen flood impacts. White topping of roads, though long-lasting, is no guarantee against floods and is, in fact, environmentally unfriendly, the mix composed mainly of cement concrete. Footpaths are again relaid with cement, preventing water from seeping into the soil. The designing of roads in Bengaluru, with its undulating topography, should be primarily aimed at preventing flooding. While roads designed under Tendersure provide an answer, it was confined to a few main roads in the central areas of the city. This model must be extended across the city, including residential areas. Potholes can be prevented with due attention to quality standards at the time of laying of the road; filling of potholes must also be done as per prescribed norms.

Encroachments and unauthorised constructions: This has been going on for years, aggravating the problem of flooding, and is perhaps the most difficult problem to tackle. It is common knowledge these violations take place with the connivance of the officials concerned and the blessings of the powers that be. The fact remains that unless this is dealt with in some earnestness, it is difficult to control flooding.

Based on the NDMA guidelines, each city must design its own plan, taking into account its topography, physical features, and other local problems. Chennai, for instance, has prepared the Chennai Flood Warning System (CFLOWS), a six-module ensemble that can predict floods due to heavy rainfall, sea level rise and an increase in the water levels of its three rivers that traverse the city (Cooum, Adyar, and Kosasthalaiyar).

BBMP must prepare a Bengaluru Flood Management Plan based on water-sensitive design and planning techniques that includes a mandatory assessment of vulnerabilities and risks, scientific mapping of vulnerable areas and hydraulic models to analyse flood patterns. It must incorporate the four measures outlined above. It is essential to involve other city agencies like BWSSB, BDA, and Lake Development Authority, adopting a coordinated approach in planning and implementation. The ward committees and resident welfare associations must be involved for storm water management at the local level.

The state government must prioritise flood management over plans such as tunnel roads, which will only add to the vehicular traffic and make flood management more difficult.

(The writer is a former chief secretary, Government of Karnataka)