A variety of trenchless and open-cut solutions to install more than 7,000 meters of water main

Orléans Water Main Link

On the eastern edge of the City of Ottawa, along the Ottawa River, lies the community of Orléans, with a population of over 110,000 residents. This growing area is serviced by only one large feedermain. A failure of this critical infrastructure would have serious impacts on the City's ability to meet daily water demands.

Recognizing the importance of improving the reliability of water delivery, the City embarked on a major initiative to install more than 7,000 meters of multi-diameter water main. A unique solution was required for the project that took into account significant operational challenges along with the need to minimize disruptions to the community and cross many environmentally sensitive features. For these reasons, a variety of trenchless and open-cut solutions were proposed, each picked to match the specific features of the area.

Goals included maximizing short- and long-term operational flexibility, determining how to best connect to the exiting piping, minimizing impacts on surrounding community, and maximizing construction cost effectiveness. The trenchless installations included an HDD crossing under Greens Creek and the Rockcliffe Parkway (590 meter long pull of 914 mm HDPE pipe up to 25 m deep), auger bore crossing under OR 174 (110 meter long steel casing), lining of existing connecting water mains (1,300 meters), renewal of 14 corrugated steel culverts along OR 174 using CIPP liners, and renewal of two concrete box culverts along OR 174. The project is the first of its kind in Ottawa to use HDD for this length crossing using such a large diameter water main.

This cost effective approach reduced environmental and stakeholder impacts, led to an easier approval process, provided operational flexibility, and met the long-term development needs of the community.