Time for a ‘sponge cities’ mission in India

Context

• In the recent Hyderabad floods, hundreds of riverbed hutments were flushed away. Thousands of homes remain submerged two weeks after the flood. The scale of destruction has been unprecedented.
• This experience is not unique to the city of Hyderabad but something that cities across India have been experiencing in recent years.
• Barely five years ago, it was Chennai that saw a massive flood costing much damage and lives; Gurugram over the past few years comes to a complete standstill during the monsoon months, and for Mumbai, the monsoon has become synonymous with flooding and enormous damages.

The case of Hyderabad

• Almost 10 years ago, scientists from the Potsdam Institute for Climate Impact Research, Germany, built climate change adaptation tools for Hyderabad.
• However, the Hyderabad Metropolitan Development Authority of that time did not use it.
• Such tools are held in trust by many civil society organisations across the country in many of our cities.
• The rainfall received in 2020 has been the highest for the month of October in a century in Hyderabad.
• Every year, the rains bring something unprecedented with them.
• But our constant, unwavering attention to the rainfall levels draws our attention away from our inability to manage the city’s drainage systems.
• The floods of October 2020 occurred because we did not discharge the water in time.
• And when we did discharge the water, we did it in a sudden, uncontrolled manner.
• The second is antiquated infrastructure.
• Hyderabad’s century-old drainage system (developed in the 1920s) covered only a small part of the core city. In the last 20 years, the city has grown at least four times its original built-up area.
• But the areas that suffered from the floods of 1908, 2001, and 2005 have not been hit by the 2020 floods.
• As the city grew beyond its original limits, not much was done to address the absence of adequate drainage systems.

Communities are left out

• The manner in which we talk about recurring floods in the city often reduces the problem to simple dichotomies of public versus private property and individual conduct versus faceless governmental action.
• This means that we neglect the issues of incremental land use change, particularly of those commons which provide us with necessary ecological support — wetlands.
• This framing also disavows the role of local communities in managing local ecosystems — people with traditional rights for fishing and farming.
• This is a lesson that has been learnt by others around the world.
• We need to start paying attention to the management of our wetlands by involving local communities.
• The risk is going to increase year after year with changing rainfall patterns and a problem of urban terrain which is incapable of absorbing, holding and discharging water.

Making cities permeable

• Urban floods of this scale cannot be contained by the municipal authorities or by the State government alone.
• They cannot be managed without concerted and focused investments of energy and resources.
• Such investments can only be done in a mission mode organisation with active participation of civil society organisations at the metropolitan scale.
• We need a mission that mitigates flood risk and provides a pathway to water security.

Sponge cities:

• The most promising idea across the world at this time appears to be the idea of “sponge cities”.
• The idea of a sponge city is to make cities more permeable so as to hold and use the water which falls upon them.
• Sponge cities absorb the rainwater, which is then naturally filtered by the soil and allowed to reach urban aquifers.
• This allows for the extraction of water from the ground through urban or peri-urban wells.
• This water can be treated easily and used for the city water supply.
• In built form, this implies contiguous open green spaces, interconnected waterways, and channels and ponds across neighbourhoods that can naturally detain and filter water.
• It implies support for urban ecosystems, bio-diversity and newer cultural and recreational opportunities.
• These can all be delivered effectively through an urban mission along the lines of the Atal Mission for Rejuvenation and Urban Transformation (AMRUT), National Heritage City Development and Augmentation Yojana (HRIDAY) and Smart Cities Mission.

Priority areas of Sponge cities:

• On a top priority, such a mission should address the following:
• Wetland Policy: The first subject is wetland policy.Regardless of ownership, land use on even this small scale of wetlands needs to be regulated by development control.
• Watersheds, terrain alteration: Watershed management and emergency drainage plan are next. This should be clearly enunciated in policy and law. Urban watersheds are micro-ecological drainage systems, shaped by the contours of the terrain.
• Detailed documentation of these must be held by agencies which are not bound by municipal jurisdictions; instead, we need to consider natural boundaries such as watersheds instead of governance boundaries like electoral wards for shaping a drainage plan.
• The Metropolitan Development Authorities, National Disaster Management Authority, State revenue and irrigation departments along with municipal corporations should be involved in such work together.
• Ban against terrain alteration: Lasting irreversible damage has been done to the city by builders, property owners, and public agencies by flattening terrain and altering drainage routes.
• Without a doubt, terrain alteration needs to be strictly regulated and a ban on any further alteration of terrain needs to be introduced.
• Our cities are becoming increasingly impervious to water, not just because of increasing built up but also because of the nature of materials used (hard, non-porous construction material that makes the soil impervious).
• To improve the city’s capacity to absorb water, new porous materials and technologies must be encouraged or mandated across scales.
• Examples of these technologies are bioswales and retention systems, permeable material for roads and pavement, drainage systems which allow stormwater to trickle into the ground, green roofs and harvesting systems in buildings.
• These not only reduce run-off and the load on infrastructure but also help keep water in the city for later use.

Stop the blame, start action

• Acknowledging the role of different actors in the city can create a practical space to begin this work.
• Doing so will not just help control recurring floods but also respond to other fault lines, provide for water security, and more green spaces, and will make the city resilient and sustainable.
• The constant search for a scapegoat to blame, while a few people try what they can, limits our capacities and only creates cycles of devastation.

Way forward

•  We can learn to live with nature, we can regulate human conduct through the state and we can strategically design where we build.
• We need to urgently rebuild our cities such that they have the sponginess to absorb and release water without causing so much misery and so much damage to the most vulnerable of our citizens, as we have seen.