The reprovisioning and upgrading the Salt Water Service Reservoirs in Western District for Water Supplies Department (the Project) involves the construction of two salt water service reservoirs in rock beneath the northern hill slopes of Lung Fu Shan immediately adjacent to the present Water Supplies Department (WSD) facilities, south of Pok Fu Lam Road. To minimise environmental impacts, the two salt water service reservoirs will be housed entirely in a rock cavern. The location and general arrangement of the Project are presented in Figure 1.1

The rock cavern will comprise two salt water storage tunnels connecting to a common section leading to an access portal. It will be excavated using a non-explosive drill-and-break tunnelling method. Tunnel boring machine (TBM) and blasting will not be used in the construction of the Project. The cavern will be lined with concrete and the water storage reservoirs will be constructed from reinforced concrete. Each of the two water storage tunnels of the rock cavern will be approximately 60 m in length and 17 m in span. These storage tunnels will be connected to a common section of approximately 40 m in length and 8 m in span, which will lead to an access portal on the hill slope. The internal tank dimensions of each of the salt water service reservoirs will be 46.8m (L) x 15m (W) x 9m (H) approximately. The two reservoirs are designed to provide a combined saltwater storage capacity of 12,000m3. Construction activities will involve:

• Slope work and portal / access tunnel construction;

• Tunnel excavation for Salt Water Services Reservoirs (SWSR) No. 1;

• SWSR No. 1 Construction;

• Tunnel excavation for SWSR No. 2; and

• SWSR No. 2 Construction