Butterfly Valley
Construction of a water tunnel connecting the Kowloon Byewash Reservoir to the Lower Shing Mun Reservoir started in 2019. The project is scheduled to be completed in 2022. The Inter-reservoirs Transfer Scheme (IRTS) consists mainly of a water tunnel, 2.8 km in length and 3 m in diameter, connecting the two reservoirs. The purpose of the tunnel is to reduce the quantity of the overflow from the Kowloon Group of Reservoirs into the Lai Chi Kok Transfer Scheme (LCKTS) and to make better use of the water collected by the Kowloon Group of Reservoirs which will otherwise overflow into the Butterfly Valley and discharge into the sea.