Amsterdam's 'Smart' Blue-Green Roofs Reduce Urban Flooding

One of China’s many “sponge cities,” Haikou, experiences virtually no flooding after transitioning to primarily green, nature-based infrastructure instead of gray infrastructure like concrete and flood barriers. Prioritizing things like parks, wetlands, mangroves, and permeable pavement allows the city’s ground to soak up more rain.

Cities in China are moving away from using traditional water managment approaches, like drainage pipes and flood walls. Instead, they are becoming “sponge cities” by installiing green infrastructure designed to absob excess water, like green roofs and ponds.

Farmers in West Bengal, India, are swapping rice for bananas to save on expenses and labor and adapt to increasingly erratic monsoons and rainfall impacting yields. The farmers use solar panels and drip irrigation setups funded by the state government to reduce emissions and minimize water loss, as bananas require a lot of water.

Flood-prone cities in the United States are turning to stormwater utility projects that charge landowners based on the amount of impervious surface on their property. The money earned from the fees is used to build green infrastructure that allows rainwater to seep into the ground instead of overwhelming storm drains and sewage systems.

In order to use less water in drought-ridden Utah, many residents are replacing their grassy park strips with vegetation and rocks that don’t need as much irrigation. As part of the “Flip Your Strip” initiative, the Weber Basin Water Conservancy District provides participants with money per square foot of grass removed. While the program is new, this idea has been tried and tested in California, where studies have shown that it is making an impact.

In London, two community-driven initiatives are working side by side to engage residents in sustainable practices. Energy Garden, a community energy cooperative, has created green spaces in rail stations offers residents community gardens, nature education, and solar power. Repower, the other initiative, works with residents to communally invest in renewable energy for low-income neighborhoods while also providing those neighborhoods with energy jobs and mentoring services.

Medellín, Colombia, is combating the urban heat island effect by creating green corridors across the city. Over 2.5 million plants and trees were carefully selected to maximize impact and planted on buildings and along roads and waterways.

Stormwater fees, which are based on property runoff, are funding infrastructure upgrades and green spaces to absorb rainwater, reduce damage from flooding and improve water quality. Several municipalities have seen reduced flood damage and increased water quality after implementing stormwater fees, and have even hosted community events to educate residents on how the fees are used to make improvements.

In Paris, building-based agriculture, like rooftop gardens, allows for the production of nutritious food close to where they will be eaten. The practice helps eliminate carbon emissions, improve food security, and improve climate resilience.

Bamboo is growing in popularity as a cheap, sustainable building option that can replace hardwoods and other common construction materials.