Bill’s Place and Mamquam Road Watermain Upgrades
Watermain engineering for Squamish’s steep terrain and an existing bridge crossing.
Client: District of Squamish
Location: Squamish, BC
Project Type: Municipal
About This Project
The District of Squamish engaged ISL to provide engineering services for two watermain projects: a new connection between Highlands Way South and Bill’s Place, and upgrades along Mamquam Road. Each required an approach tailored to challenging terrain, existing infrastructure and municipal operating needs.
At Bill’s Place, the watermain connection traverses a forested municipal right-of-way with approximately 30 metres of elevation change, an existing sanitary sewer and a switchback walking path. The work included approximately 130 metres of watermain, a pressure-reducing valve station, and associated electrical and monitoring systems. ISL provided civil design, geotechnical coordination, contract administration and construction inspection.
The steep hillside required careful consideration of equipment access, pipe resistant and construction methods. ISL adjusted the alignment, chamber location and fittings to address the constructability, while the contractor used a specialized spider excavator through the hillside section. Measures to limit tree removal, erosion-control matting and hydroseeding addressed disturbance and supported slope restoration.
Pressure management presented another significant challenge. The valve station was designed to reduce water pressure from approximately 150 psi to 32 psi, with specialized valve trim to limit damage caused by cavitation. Flow and pressure monitoring, alarms and communications were designed for integration with the District’s existing supervisory control and data acquisition system.
For Mamquam Road, ISL developed a watermain upgrade design incorporating buried PVC pipe and insulated steel pipe supported from an existing bridge. The design routed the pipe through existing openings in the bridge abutment wing walls. Structural supports, flexible expansion joints, insulation and aluminium jacketing accommodated movement and protected the exposed pipe.
Bill’s Place and Mamquam Road were both completed in 2025. Together, the projects demonstrate coordinated engineering responses to steep terrain and existing structures within Squamish’s water network.
Key Features
- 130 m watermain connection through a forested hillside
- Pressure-reducing valves designed to manage a substantial pressure drop
- Specialized spider excavator for challenging hillside access
- Erosion control and revegetation to restore disturbed slopes
- Remote flow and pressure monitoring designed for municipal system integration
- Bridge-mounted watermain design with insulation and flexible joints to accommodate movement