Innovative Design of the LID Facilities of Congdu Ecological Grange

This study addresses the innovative design of the low impact development (LID) facilities of the Congdu Ecological Grange in Conghua District, Guangzhou, China. The stormwater in the project area was treated by innovative LID facilities such as raingarden, bioretention swales and terrace trenches, and the treated stormwater was diverted to the landscaping lakes for irrigating the entire project during the dry season. To maintain the lake water levels and water quantity for irrigation, the polluted Yangmeikeng River water is pumped into the raingarden on the southwest corner, from which treated water enters the upper west lake. The synthetic 133mm 4-hour storm event with 10 year return period was used to design the LID facilities and other pipeline conveyance. The 24 hour historical rainfall of 389mm was used to evaluate the LID facilities responses to an extreme event. The simulation results show that the LID facilities have very large flood control performance.