DTI is intended to upgrade Edmonton’s downtown storm sewer infrastructure to facilitate growth in the downtown core area. Initially estimated at $40M, DTI seeks to reduce the amount of combined sewer in the downtown core as well as the total combined sewer overflow into the North Saskatchewan River. The project consists of approximately 2.5 km of storm tunnel between 111 Avenue and 100 Avenue. Included in the design and construction are five vertical shafts, connections between trenchless tunnels and tie-in points, and four additional lateral sewers that discharge into the main trunk. Throughout the project SMA has provided services such as public consultation, risk management, change management, cost estimating, scheduling, quality management, traffic safety plans, Project Development Rating Index assessment, in addition to conducting regular meetings and reports for status updates and project coordination.

The project presented many unique challenges, including tight completion deadlines, tunneling under existing LRT tunnels on Jasper Avenue, integration with interdependent projects concurrently under construction, and mitigating public impact in busy downtown neighbourhoods, while contending with the possibility of risky soil conditions.

To overcome these challenges, value engineering, risk assessment, and constructability review workshops were conducted for project stakeholders at each stage to evaluate options and assess project risks. Innovative approaches were implemented in project procurement and delivery.  The project was divided into two portions – an in-house constructed portion (2.2 km) and an external company-constructed portion (0.3 km) in order to ensure proper risk allocation.

To meet the deadline and project coordination requirements – and despite funding constraints – the project was broken into three phases, allowing for simultaneous construction work to occur, thus expediting the project. Innovative approaches were implemented in project procurement and delivery. Advanced construction management tools, including Earned Value Analysis, Method Productivity Delay Model, and a 6-week look ahead schedule were applied to track, oversee, and manage construction progress, cost, and schedule during the construction to ensure success.