Stanley Park Water Supply Tunnel – Chilco Shaft Area
In September 2021, a project permit was issued to the Greater Vancouver Water District to construct a major water infrastructure project, referred to as the Stanley Park Water Supply Tunnel. The work will replace a section of existing water supply infrastructure. When complete, the new tunnel will meet current seismic standards, help ensure the continued reliable delivery of clean, safe drinking water to the region, and increase the capacity of the existing system to support the region’s growing population. The project is located south of Lost Lagoon (Stanley Park) and adjacent to Chilco Street, Vancouver, BC, on federal lands managed by the Vancouver Fraser Port Authority.
The project was approved subject to 36 permit conditions that the Greater Vancouver Water District must meet to ensure the project does not result in significant adverse environmental effects.
About the project
The Greater Vancouver Water District is planning to construct a major water infrastructure project, referred to as the Stanley Park Water Supply Tunnel, to replace a section of existing water supply infrastructure. The Project involves the excavation of a 1,400 metre long, 4.2 metre diameter, water supply tunnel that will range between 45 to 50 metres below the ground surface of Stanley Park, connected to three access shaft areas. The Chilco Shaft Area is located within the port authority’s jurisdiction.
While the majority of the Project works are outside Port Authority jurisdiction, the Project works located within Port Authority jurisdiction include:
- Tunneling approximately 390 m under Lost Lagoon;
- Construction laydown area, which will include:
- installation of construction fencing,
- vegetation removal,
- tree clearing and
- temporary site grading.
- Movement of construction vehicles;
- Construction of temporary pedestrian and cyclist pathways, each approximately 150 m long (new permanent pathways will be reinstated to existing configuration once construction work has completed);
- Replacement of approximately 75 m of the existing West End Interceptor No. 1 (1,067 mm dia combined storm / sanitary pipe) in the construction laydown area;
- Potential protection / replacement of approximately 75 m of the existing West End Interceptor No. 2 (610 mm dia);
- Installation of temporary instrumentation to support the excavation works;
- Identification of utilities (potholing, hydrovac etc.) and protection / relocation / replacement;
- Discharge of construction water, and potentially water main disinfection, into Lost Lagoon / Burrard Inlet through West End Interceptor No. 1, or through a temporary line, if sanitary discharge is not possible via sanitary main – West End Interceptor No. 2 (the disinfection procedure has yet to be determined); and
- Final regrading and landscaping, including the installation of minor hardscape elements (i.e. benches, retaining walls, etc.).
The expected footprint of the Chilco Shaft Area is 2,900 square metres and the length of the supply tunnel portion located within Port Authority managed land is approximately 390 m.