Residents exercise in the sponge park on Jan 16. [Photo/Xinhua]

Tianjin's first sponge park has been built in Nankai district's Santan Xili community. All the materials used in the sponge park have outstanding water holding capacity and permeability, and the park uses a concave herbaceous field and grassed waterways to absorb water like a sponge on rainy days and seep water on dry ones. It also uses a green ecology landscaping concept.

A staffer shows the water absorption capacity of the sponge park.[Photo/Xinhua]