Canadian Consulting Engineer

Naturalization of Toronto’s Don River and flood protection to cost more

October 20, 2016   CCE

Aerial view of the existing conditions (right) and rendering of the proposed naturalization and flood protection for the Port Lands in downtown Toronto.

Aerial view of the existing conditions (right) and rendering of the proposed naturalization and flood protection for the Port Lands in downtown Toronto.

Waterfront Toronto has released an extensive Due Diligence Report on the proposed Port Lands Flood Protection Project. The plan provides “greater certainty” regarding the costs, schedule and risks of a project to naturalize the lands around the Don River mouth. The river enters Lake Ontario to the east of Toronto’s downtown core.  The project would also provide flood protection for the area and lay the groundwork for billions in development, but the price has risen from earlier estimates..

Key components of the seven-year project include creating two new outlets for the Don River – a 1,000 metre river valley and greenway – that will safely convey flood waters into Lake Ontario, as well as infrastructure such as roads, bridges and services to support development. This project also includes 29 hectares of naturalized area in the river valley, two new parks and 14 hectares of aquatic habitat.

Developed in cooperation with the City of Toronto, the Toronto and Region Conservation Authority and the Toronto Port Lands Company, the due diligence report finds that the estimated cost of the project has risen from $975 million to $1.25 billion (in year-of-expenditure dollars). The cost includes a 30 per cent contingency.

Waterfront Toronto says the revised  estimate for the project is largely due to the discovery of flowing sand and compressible peat in the project area that will require additional excavation, soil and groundwater treatment.  There is also a requirement for enhanced erosion control and material handling costs, as well as a need for additional environmental risk management measures.

They say a major risk is the lack of an established environmental regulatory approval process for creating a river valley in a brownfield. The project team is collaborating with partner agencies to confirm an effective environmental approval process for this.

Will Fleissig, Waterfront Toronto’s CEO, said: “Excavating a new river mouth in an urban post-industrial brownfield is a pioneering project for Toronto. The opportunity here is immense – no other North American city has such an asset on the doorstep of downtown that can support the creation of new communities and new economic opportunities.”

The project team involved many consulting firms, who were each given a specialized task to work on. The team included: Michael Van Valkenburg Associates, CH2M, Earthwork, LimnoTech, WSP/MMM, Golder, Inter-Fluve, W.F. Baird & Associates, Riggs, HDR and GHD, plus costing, economic and legal consultants.

The results were used to inform a probabilistic computer risk simulation that modelled 10,000 possible project outcomes; the modelling concluded that there is a 90 per cent probability that the Project can be completed for $1.25 billion or less.

The project has a start date in 2017.  The construction of the project and future development in the project area is projected to result in $5.1 billion in value added to the Canadian economy, numbers which do not include the additional long-term economic impact associated with the proposed development of the First Gulf/Unilever site.

The Port Lands is a 400-hectare (880 acre) parcel of waterfront land downtown south of Lake Shore Boulevard and the Keating Channel.  An earlier phase involved building flood protection infrastructure in the West Don Lands portion. It now protects 210 hectares of eastern downtown Toronto and has spurred $1.3 billion in private sector investment .

The Ontario Ministry of the Environment and Climate Change has previously approved the Don Mouth Naturalization and Flood Protection Project EA, after extensive stakeholder engagement and public consultation over the past decade.

To read the Waterfront Toronto press release, click here.

To see a video of the Port Lands development, click here.

Categories

Engineering


Print this page

Related Stories

Leave a Reply

Your email address will not be published. Required fields are marked *

*