Use of Rubber Dams for Flood Mitigation in Hong Kong

Rubber dams are constructed by the Agriculture and Fisheries Department in Hong Kong for the replacement of polluted agricultural weirs that are still in use. The main purpose of these dams is to impound water for irrigation. The reason the dams may be used as devices to mitigate flooding is that they are inflatable and deflatable. When a dam is inflated, it serves the function of an agricultural weir (low-level dam). However, when a dam is deflated, the barrier to water flow is removed, and hence the dam functions as a flood mitigation device. When the river water level reaches a preset level, the dams deflate automatically, and the risk of flooding is therefore reduced. Although rivers in Hong Kong are relatively small, they can become violent during severe rainstorms, resulting in flooding in many parts of the New Territories, north of the Hong Kong Island and the Kowloon Peninsula, from time to time. Due to the versatility of the rubber dams, they are of great benefit to Hong Kong's local farming communities.