During the major rainstorms in August 2000, April 2006 and June 2008, severe flooding incidents occurred at Happy Valley and adjacent areas including Sing Woo Road, Wong Nai Chung Road, Morrison Hill Road, Lap Tak Lane, the Happy Valley Racecourse and the Happy Valley Recreation Ground. In these busy and densely populated areas, conventional drainage improvement schemes would require extensive upsizing of existing drains or laying of new drains, which would involve extensive road excavation works, leading to disruption to the public and commercial activities. Congested underground utilities will also jeopardise the viability of the conventional schemes.

In view of this, Drainage Services Department (DSD) commenced the construction works of Happy Valley Underground Stormwater Storage Scheme (HVUSSS) in 2012 comprising the construction of a 60,000 cubic metres (which is equivalent to the total volume of 24 standard swimming pools) underground stormwater storage tank underneath the Happy Valley Recreation Ground, a box culvert of about 650 metres long and a stormwater pump house with a peak flow rate of 1.5 cubic metres per second.