Drainage Services Department’s Happy Valley Underground Stormwater Storage Scheme represents new thinking on stormwater management
Black & Veatch has won the 2017 Hong Kong Awards for Industries: Innovation and Creativity Grand Award. The award recognises the company’s role as the hydraulic designer of the recently completed Happy Valley Underground Stormwater Storage Scheme (HVUSSS) for the Drainage Services Department of Hong Kong SAR (DSD).
The HVUSS is an example of how Hong Kong is rethinking stormwater management. A 60,000m3 capacity underground storage tankwas built below the famous Happy Valley Recreational Ground. The tank temporarily stores stormwater during peak times, relieving pressure on the drainage system and integrating real-time data of water and tidal levels.
“The award reflects how DSD is embracing innovation and smart city technologies to overcome climate change and urban density challenges. Rather than digging deeper drains, the scheme integrates real-time data to act like a release valve during rainstorms, and the new thinking saved the city money and avoided major public disruption along a busy highway.”
Andy Kwok, Director, Black & Veatch in Hong Kong
Over the last 50 years, infill development and extension of the urbanised areas into Hong Kong’s foothills have significantly increased runoff and flood risks while rainfall intensity has become more unpredictable. In August 2000, April 2006 and June 2008 severe flooding occurred in Happy Valley and its adjacent area during heavy rainstorm events.
Black & Veatch and the Drainage Services Department of the Government of Hong Kong Special Administrative Region (DSD) also received the 2012 Planning Award for International Water Association’s East Asia region for the HVUSSS.
·Black & Veatch was the hydraulic designer on the HK$1 billion HVUSSS. The project commenced construction in September 2011 and the scheme was fully commissioned in March 2017.
·The objective of the HVUSSS is to provide off-line stormwater storage in the Happy Valley catchment during a 1-in-50 year rainstorm event. Major components include an inlet structure, twin cells diversion box culvert with overflow side weir system, an underground storage tank of 60,000m3 and a pump house with a pumping rate of 5,400 m3/hr. During heavy rainstorms, excess runoff in the diversion box culvert will enter the storage tank via the overflow weir system. After rainstorms the storage tank will be emptied to prepare for upcoming rainstorm events.