Sponge city

Sponge city

Subject: Environment

Section: Msc

Context: Recent Auckland floods demonstrated that even storm water reform won’t be enough – we need a ‘sponge city’ to avoid future disasters.

Sponge City:

• In the early 2000s, Chinese architectKongjian Yu created the concept of the “sponge city”. It’s a relatively simple idea, but a big departure from the way we typically build infrastructure.
• The concept incorporates green roofs, rain gardens and permeable pavements to absorb and filter water.
• Better catch systems hold rainwater where possible and reuse it. More green space and trees are also incorporated into street and neighbourhood designs.
• Within the sponge city concept is a way to mitigate flooding using “water sensitive urban design”. With this approach, we create spaces that better manage flooding through systems that mimic the natural water cycle.
• This can also include floodable infrastructure and parks to take the pressure off more vulnerable parts of the city.
• 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.
• 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.
• There are three main facets to developing such systems: protecting the original urban ecosystem, ecological restoration, and low-impact development.
  • Protection focuses on the city’s original ecologically sensitive areas, such as rivers, lakes, and ditches. Natural vegetation, soil, and microorganisms are used to gradually treat the aquatic environment and restore the damaged urban ecosystem.
  • Restoration measures include identifying ecological patches, constructing ecological corridors, strengthening the connections between the patches, forming a network, and delineating the blue and green lines to restore the aquatic ecological environment.
  • Mandatory measures apply to urban roads, urban green spaces, urban water systems, residential areas, and specific buildings to protect ecological patches, maintain their storage capacity, strengthen source control, and form ecological sponges of different scales.