time-for-a-sponge-cities-mission-in-india

Context: The torrential rains in Hyderabad killed over 50 people. In the past, it was Chennai that saw a massive flood costing much damage and lives. For Mumbai, the monsoon has become synonymous with flooding and enormous damages.

The case of Hyderabad

  • Unprecedented rainfall: In September 2019, the rainfall was the highest in 100 years. The rainfall received in 2020 has been the highest for the month of October in a century. 
  • Ignoring scientific tools: Scientists from the Potsdam Institute for Climate Impact Research, Germany, built climate change adaptation tools for Hyderabad. However, the Hyderabad Metropolitan Development Authority did not use it.
  • Mismanaging 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. 
  • Antiquated infrastructure: 
    • Hyderabad’s century-old drainage system (developed in the 1920s) covered only a small part of the core city. 
    • And as the city grew beyond its original limits, not much was done to address the absence of adequate drainage systems.
  • Communities left out: The issues of incremental land use change, particularly of those commons which provide us with necessary ecological support — wetlands were neglected. 

    • The role of local communities in managing local ecosystems — people with traditional rights for fishing and farming was also ignored.

Way forward:

  • Sponge cities : They absorb the rain water, which is then naturally filtered by the soil and allowed to reach urban aquifers. 
    • This water can be treated easily and used for city water supply. 
    • This implies building 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. 
    • Investments can only be done in a mission mode organisation with active participation of civil society organisations at the metropolitan scale. 
  • Porous building materials: Our cities are becoming increasingly impervious to water, not just because of increasing built up but also because of hard, non-porous construction material that makes the soil impervious. 
    • To improve the city’s capacity to absorb water, bioswales and retention systems, permeable material for roads and pavement, drainage systems can be used. It will allow storm water to trickle into the ground, green roofs and harvesting systems in buildings. 
  • Wetland policy: We need to start paying attention to the management of our wetlands by involving local communities. 
    • In most of our lakes, the shallow ends, which often lie beyond the full tank level, have disappeared. These shallow ends are called wetlands. 
    • They are sometimes owned by private individuals, other times existing as ecological commons. 
    • Regardless of ownership, land use on even this small scale needs to be regulated by development control.
  • Detailed documentation of wetlands and watersheds: Urban watersheds are micro ecological drainage systems, shaped by contours of terrain.

    • 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
    • Builders, property owners, and public agencies have been flattening terrain and altering drainage routes. This causes irreversible damage.
    • Terrain alteration needs to be strictly regulated and a ban on any further alteration of terrain needs to be introduced. 
  • Stop the blame: Acknowledging the role of different actors for the city can create a practical space to begin this work. The constant search for a scapegoat to blame should stop.

We need to urgently rebuild our cities such that they have the sponginess to absorb and release water. Doing so will not just help control recurring floods but also respond to other fault lines, provide for water security, more green spaces, and will make the city resilient and sustainable.

Image source: ScienceDirect.com