To prevent flooding, especially during heavy rains, Beijing municipal government has begun to build sponge city by improving concave overpass, expanding reservoir, using water permeable bricks, and building sponge parks. Haidian District set up “Renchuang Professional Rainwater System”, in order to make full use of rainwater, such as improving the condition of Wanquan River. The bricks used in Haidian project can conserve water and cool the city, as well as allowing the earth to breathe. The tiny pores of bricks can also help purify rainwater, removing pollutants and impurities.