Tour 4 – Sponge City
This tour will include two drainage projects which adopt “Sponge City” concept. It means the city could absorb, store, infiltrate and clean excess stormwater during rainy days and release the stored stormwater afterwards to avoid flooding.
The Happy Valley Underground Stormwater Storage Tank was built under the Happy Valley Recreation Ground, with a 60,000 m3 storage tank to store runoff during heavy rainstorm.
The Hong Kong West Drainage Tunnel intercepts stormwater from mid-levels, so as to reduce the burden of the existing drainage systems in the downstream. The total length of the tunnel is 10.5km, with diameter ranges from 6.25m to 7.25m.