7 examples of Sponge Cities, Seawalls, Cool Roofs


Preparing for life after overshoot in cities and towns means preparing for floods, sea level rise, hurricanes, heat waves, fires or earthquakes. Not easy, but essential. This describes 7 examples of sponge cities, seawalls, and cool roofs.

Building local resilience is essential these days. Here are some cases of good preparation:

  1. Barcelona is built on a plain and it has a lot of concrete and asphalt, which absorb heat. The city is working to reduce the urban heat island effect by planting more trees, installing cool roofs, and using lighter-coloured materials in construction.

 Barcelona is also making its public spaces more comfortable during heatwaves by installing misters, fountains, and shaded areas. The city is also working to create more green spaces, which can help to cool the air.

2. Tokyo is located in a seismically active region, and it is also on the coast, which makes it vulnerable to tsunamis. In addition, Tokyo is located in a typhoon-prone area.

In response to these threats, Tokyo has taken a number of steps to prepare for earthquakes, tsunamis, and typhoons. These steps include building earthquake-resistant infrastructure, such as bridges, buildings, and roads. The city is also working to improve the safety of its water supply and its power grid.

Tokyo is strengthening its levees and seawalls to protect the city from flooding caused by tsunamis and typhoons. It is developing a disaster relief plan that will ensure that residents have access to food, water, and shelter in the event of a natural disaster. Tokyo is working with other countries to share information and best practices on disaster preparedness.

3. Changde in China is prone to flooding.

Changde’s approach to becoming a sponge city involves the integration of green infrastructure, water conservation, and sustainable urban planning to manage rainwater and mitigate flood risks.

Changde has installed permeable pavements that allow rainwater to infiltrate the ground instead of running off. These pavements are designed to reduce surface water runoff and replenish groundwater levels.

Permeable paving like this prevents flooding

The city has implemented rainwater harvesting systems to collect and store rainwater for various purposes, such as irrigation, landscaping, and non-potable uses. This practice reduces the demand on traditional water sources.

Changde has created wetlands, retention ponds, and green spaces that act as natural sponges, absorbing and storing excess rainwater during heavy downpours. These areas not only help prevent flooding but also provide recreational and ecological benefits. It also supports green roofs or planted roofs.

Changde’s urban planning incorporates sustainable drainage systems and flood-resistant design principles. By factoring in natural water flow patterns and integrating green infrastructure, the city aims to minimise flood risks in its development projects.

The city conducts public awareness campaigns to educate residents about water conservation, flood prevention, and the importance of maintaining sponge city features.

4. Boulder, Colorado, prone to wildfires, has fire-resistant infrastructure and has been educating its citizens to do this for their homes.

5. There are many places that have built seawalls. Surabaya in Indonesia has both seawalls and pumps. Halifax in Canada has seawalls and shelters, and Miami has seawalls and pumps.

6. In New Zealand, especially in Christchurch and Wellington there has been an emphasis on earthquake-proofing buildings and infrastructure.

7. Venice, prone to flooding has a series of barriers called MOSE. Copenhagen prone to heavy downpours has green spaces and infrastructure that deals with a lot of stormwater.