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 and the Happy Valley Racecourse and the Recreation Ground. In these busy and densely populated areas, there are limitations in carrying out extensive on-line upsizing of the existing drains, which would involve extensive road opening works. To avoid serious disruption to the public and minimize complication diversion of the congested underground utilities, an underground storage tank becomes a good solution to the flooding problem. The underground storage tank will temporarily store part of the stormwater collected from the upstream catchment for attenuating the peak flow through the downstream stormwater drainage systems after heavy rainstorms. The stormwater will be discharged via pump and gravity drains to the outfall and thus greatly reduces the risk of flooding to low-lying area of Happy Valley and Wan Chai District.


Review of Past Flooding Incident

Three major recent flooding incidents in Wan Chai District:

  • August 2000
  • April 2006
  • June 2008



Overall Drainage Improvement Works for Hong Kong Island

Three approaches to alleviate flooding risks of Wan Chai District:

  • Interception at the Upstream:
    • Hong Kong West Drainage Tunnel (Click here for official website)
  • Storage in the Midstream:
    • Happy Valley Underground Stormwater Storage Scheme (This project)
  • Upgrading Pipes at the Downstream:
    • Lower Catchment Drainage Improvement works


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