China Building 30 'Sponge Cities' That Soak Up Floodwater and Prevent Disaster

Like many places around the world, Chinese cities are considering ways to combat flooding in the face of climate change. Increased urban development has made flooding worse, and has turned some neighborhoods into vulnerable waterfront locations.

By LEANNA GARFIELD

In 2010, landslides from flooding killed approximately 700 people and left over 300 missing in three-quarters of China’s provinces. Just this July, heavy rains pummelled southern China, flooding towns, destroying homes, and killing at least 56 people.

In recent years, fatal floods like these have become regular occurrences. The number of Chinese cities struck by floods has more than doubled since 2008, according to The Economist. Some scientists say that rising global temperatures are making rainfall from storms more destructive and frequent.

TurenscapeYanweizhou Park in Jinhua, eastern China.

The Chinese government is now pursuing an idea that could alleviate the problem: sponge cities.

Launched in 2015, the Sponge City Initiative invests in projects that aim to soak up floodwater. The projects are being built in 30 cities, including Shanghai, Wuhan, and Xiamen. By 2020, China hopes that 80% of its urban areas will absorb and re-use at least 70% of rainwater.

To date, the cities have received more than $US12 billion for sponge projects, according to China Daily. The central government funds around 15% to 20% of costs, with the remainder funded by local governments and private developers.

Lingang, a planned city in Shanghai’s Pudong district, hopes to become China’s largest sponge city project. As CNN notes, in the past two years, the city government has spent $US119 million planting greenery on rooftops, building wetlands for rainwater storage, and constructing permeable roads that store runoff. In early 2016, Shanghai announced the construction of 4.3 million square feet of rooftop gardens throughout the entire city.

In April, utility company Suez started installing a new 7-square-mile drainage system in Chongqing. The system’s embedded sensors will allow local officials to monitor their sewer and stormwater networks to mitigate the risk of flooding, according to the company.

Suez A semi-fantastical rendering of what Chongqing, China will look like with Suez’s new drainage system.

Many of the projects incorporate green space, like wetlands and bioswales, which naturally help absorb water. The efforts seek to reduce the amount of rainwater runoff.

Though the Yanweizhou Park in Jinhua, eastern China, opened in 2014 (before the initiative began), it serves as a model for the type of flood-resilient, green infrastructure the country wants to continue building.

Featuring a series of winding pedestrian paths, it’s designed to exist with floodwater during heavy rainfall. The images below show what the park looks like before and after monsoons, respectively:

TurenscapeYanweizhou Park in Jinhua, eastern China.

The initiative is facing some challenges, according to a 2017 report from the China Institute of Water Resources and Hydropower Research, a research institution under the country’s Ministry of Water Resources. After surveying all 30 cities, the researchers noticed several roadblocks, including “ambitious goals without sound research basis,” unavailable green materials, and planning models that are too homogeneous and not locally specific.

China is also in the middle of a growing municipal debt crisis, making funding some of the projects difficult.

Source: Business Insider

Media

Taxonomy

• Water
• Urban Drainage
• Integrated Urban Water Management
• Stormwater Management
• Watershed
• Flood Management
• Stormwater
• Infrastructure
• Water Storage
• Integrated Infrastructure
• Storm Water Management
• Urban Drainage System
• Urban Water Infrastructure
• Infrastructure Management
• Flood management
• Flood Risk Management
• Water
• Green Technology
• Water
• Urban Design
• green infrastructure