RC Harris Water Treatment Plant

Location: Toronto, Ontario
Duration: October 2004 - June 2006
Project Team: Kenaidan Contracting Ltd., Deep Foundations Contractors Inc., Is

Project Details

A series of underground tanks were built into the hillside located along the shore of Lake Ontario. The tanks were situated between two structures of classical Art Deco Architecture deemed to be of historical and architectural significance by the Ontario Heritage Act.

Two stepped excavations – 12 metres and 10 metres deep – were executed while the water treatment plant remained active providing potable water to more than 2.5 million people in the Toronto area.


To ensure movements at the critical expansion joint, located immediately behind the front footing of the main filtration building were no greater than 3mm, monitoring of existing structures as well as intake outlet tunnels was completed using precision survey points. Shoring deflection throughout the two main excavations was monitored by way of inclinometers, electrolevels, and pile targets. Additional monitoring employed on the site included thermistors, water levels, and vibration monitoring as well as tieback load capacities which were documented via SMART cables.

Noteworthy Aspects

Due to the high-profile nature of this project as well as the importance of its continuing functionality during construction, it was necessary to provide real-time results of our monitoring by way of reporting our findings immediately on-site. A trailer was set-up with a work station for our technicians to provide our client with the data they needed as early as possible.

Once the key issues regarding the critical expansion joint were addressed, we were able to focus the specialized monitoring needs of our client.

Four vibrating wire extensometers were installed within the holding tanks, which were decommissioned for 48 hours for the purpose of installing our instrumentation.

Acutely aware of the site’s requirements, we were able to modify our reading frequencies at a particular instrument or location as requested, providing our clients with a higher level of comfort throughout the foundation construction phase.