Client: City of Ottawa
Location: Ottawa, Ontario
Size: N/A
JLR was retained as the Prime Consultant for the Manotick Watermain Link (MWL) Phase 2 project. This project represents the second phase of the City of Ottawa’s (City) long-term plan to improve redundancy and reliability to the Village of Manotick while also providing additional capacity to service the growing demands of a planned residential development, Minto’s Mahogany community. JLR also completed the award-winning first phase of the watermain extension, the MWL Phase One and North Island Link project, which extended close to 2,500 m of 600 mm transmission watermain from the Riverside South Community to the north end of Long Island.
The MWL Phase 2 project consists of close to 4,000 m of 400 mm watermain, starting from the Hillside Gardens connection located at Bravar Drive and McLean Crescent at the north end of Long Island, continuing southwards along Bravar Drive, Long Island Road and Van Vliet Road, crossing the west branch of the Rideau River at the south end of Long Island, and tying into the existing watermain connection at the intersection of Manotick Main Street and Bridgeport Avenue. Residents fronting the new watermain were also given the option of connecting to it.
Microtunneling was selected as the preferred method to complete the trenchless crossing of the Rideau River, as other methods were deemed unsuitable for the subsurface conditions or had a high degree of risk due to the physical constraints of the site. Challenges with the subsurface conditions that influenced the design for the trenchless crossing included the potential for mixed face conditions, high groundwater inflows that could flood the excavation, and very hard and slightly abrasive rock that could wear the cutting discs. To address these risks, watertight shafts were extended through the overburden and into the bedrock, so that the horizontal bore was completely within competent bedrock and with sufficient cover. A slurry microtunnel boring machine was required to balance the groundwater pressures at the face of the excavation and was sized to allow for person entry if disc cutter replacement was required.
The Rideau River falls under federal jurisdiction and required approvals from Parks Canada and the National Capital Commission as well as the Rideau Valley Conservation Authority, Transport Canada, Department of Fisheries and Oceans, and the Ministry of the Environment Conservation and Parks.
The installation and disturbances resulting from the new watermain along Long Island provided opportunities for local improvements, including:
- The addition of a new sidewalk and pedestrian crossover along local roads, improving pedestrian safety and comfort
- Reinstatement of a City park that was used as a staging area, allowing for invasive species to be removed, higher value mature trees to be protected, and the site to be redesigned to better serve community use
- Improvements to drainage through the replacement of deteriorated culverts, regrading of swales and ditches, and addition of new storm infrastructure
JLR is proud to support the City of Ottawa in its commitment to providing reliable, safe drinking water and contributing to the critical infrastructure that supports the ongoing efforts to build more housing.