China's 'sponge cities' aim to re-use 70% of rainwater

Asian cities are struggling to accommodate rapid urban migration, and development is encroaching on flood-prone areas. Recent flooding in Mumbai was blamed in part on unregulated development of wetlands, while hastily built urban areas are being affected by flooding across India, Nepal, and Bangladesh.
Read more: http://edition.cnn.com/2017/09/17/asia/china-sponge-cities/index.html?source=Snapzu