Beijing is collaborating with the US state of Wisconsin to build a "sponge city" by creating an ecological circle, from the removal of water to its sustainable return to nature.
The Chinese capital city's water authority, together with The Water Council nonprofit organization in the United States and the Wisconsin Economic Development Corp, hosted a water conference on Wednesday to transfer the US technology, following a similar one in Nanjing, Jiangsu province, two days earlier.
On the theme of "One Water, One World", the meeting was the first event between the two countries on a water solution, with a special focus on building a "One Water" sponge city circle.
Milwaukee, a city in Wisconsin, accommodates over 200 water technology companies and has become the global center of water technology resources.
"The state of Wisconsin is considerably experienced in dealing with this issue because of the expertise and knowledge all these companies had," said Terry Branstad, US ambassador to China. "And Beijing obviously has a significant strategy to deal with the water issue and the need to have reliable, clean water for the over 21 million residents."
One of the sponge city pilot areas in Beijing is located in the city's subsidiary administrative center Tongzhou district, an area of 19.36 square kilometers. Eight categories of projects - including building and community, road and square, park and greenbelt, and water system renovation - are on schedule.
The city plans to have 20 percent of its urban areas meet the sponge city standards by 2020, and 80 percent in another 10 years.
Pan Anjun, deputy director of the Beijing Water Authority, said that a dozen policies related to rainwater collection and sponge city have been formulated. The upcoming Opinions on Advancing the Sponge City Development in Beijing will further strengthen the foundation of building a sponge city.
The sponge city concept was introduced in China in 2012. In March, Premier Li Keqiang said in his Government Work Report that sponge city construction will be expanded nationwide.
Zhang Shuhan, assistant chief engineer of Beijing Water Science and Technology Institute, said sponge city building is urgent in modern cities, as challenges are rising in cities.
The most severe challenges cities like Beijing face is decreased groundwater, decreased useful water resources, increased pollution and increased flooding probabilities, Zhang said.