Hong Kong commissions Tsuen Wan Drainage Tunnel
3 April 2013The Tsuen Wan Drainage Tunnel was commissioned on 28 March, the Hong Kong government announced last week. The new tunnel is expected to raise the flood protection level of the Tsuen Wan and Kwai Chung areas.
The 5.1km tunnel extends from Yau Kom Tau in Tsuen Wan to Wo Yi Hop in Kwai Chung and is one of the large-scale flood prevention projects of the Drainage Services Department, the government stated.
"The design capacity of the tunnel is over 220cu.m metres per second, which is equal to the rate of filling up an Olympic-size swimming pool in 11 seconds," said Wai Chi-sing, permanent secretary for development (Works). "Such a flow rate is the highest among all drainage tunnels in Hong Kong. The tunnel will considerably alleviate the flooding impact on the Tsuen Wan and Kwai Chung areas during heavy rainstorms."
Chan Chi-chiu, the director of drainage services, said: "In order to maintain a certain stream flow for the sake of ecological balance downstream, all intakes will intercept floodwater only when the amber rainstorm signal or above is in force."
Works for the USD 1.5bn project commenced in December 2007. The tunnel will intercept surface run off from the uphill catchment of Tsuen Wan and Kwai Chung for direct discharge into the sea near Yau Kom Tau, thereby relieving the loading of the existing drainage system in the downstream urban areas.
To further enhance Hong Kong's overall ability to withstand flooding, the Drainage Services Department has completed a number of large-scale projects including the drainage tunnels in Hong Kong West and Lai Chi Kok commissioned last year, the government added. The department also launched the Happy Valley Underground Stormwater Storage Scheme in 2011.
