Ontario Power Generation

Why is OPG building a third tunnel?
Why now?
What is the cost?
What method is being used to build the tunnel?
Where is the water for the third tunnel going to come from?
What will be the effect on water flowing over the falls?
Where will the tunnel run?
Where is the Tunnel Boring Machine (TBM) Big Becky right now?
When did the project begin, and when will it be complete?
Who is building the tunnel?
How is the project being funded?

Why is OPG building a third tunnel?

Ontario needs clean, renewable electricity, and the new tunnel will allow OPG to divert more water when it is available, increasing the yearly output of clean, renewable hydro electricity from OPG’s Sir Adam Beck generating stations by about 1.6 billion kilowatt hours, enough electricity for a city of 160,000.

Originally, the Canadian share of the water available for power generation was used at Toronto Power GS, Ontario Power GS, Rankine GS, as well as the Sir Adam Beck stations. All but the Sir Adam Beck stations have been retired.

Currently, Niagara River water available to Canada for power generation exceeds the capability of the existing Sir Adam Beck power canal and diversion tunnels (about 1,800 cubic metres per second) approximately 65 per cent of the time. With the tunnel, this will be reduced to about 15 per cent of the time

Why now?

Ontario’s need for electricity continues to grow. Ontario needs more clean, renewable electricity. As the older, less efficient plants near the crest of the Falls (Toronto Power, Ontario Power and Rankine) have been retired, Ontario’s ability to fully utilize the Canadian share of the Niagara River water available for power generation has been reduced.

In 2004, the Ontario government endorsed OPG’s Board decision to proceed with the project.

What is the cost?
The value of the design/build contract for the Niagara Tunnel Project is about $600 million. The total project is expected to cost about $985 million. In addition to the design/build contract, this estimate includes:

Cost of remedial work at the retired Ontario Power and Toronto Power generating stations at Niagara Falls as part of their reversion to the Niagara Parks Commission and agreement on the long term disposition of water rights for use in the new tunnel;

Cost of satisfying the conditions of the project's Environmental Assessment approval;

Cost of retaining an external consultant with international tunneling experience as Owner's Representative to review and monitor the design and construction activities on OPG's behalf;

Cost of a comprehensive insurance program;

Interest cost during construction, and

Contingency to cover unforeseen circumstances.

What method is being used to build the tunnel?

The world’s largest hard rock boring machine, named Big Becky, will bore a tunnel 14.4 m in diameter under the City of Niagara Falls. The tunnel is about 1.5 times larger in diameter than the Euro Tunnel railway tunnels under the English Channel.

As it is being bored the tunnel is reinforced with a combination of steel ribs, wire mesh, rock bolts and shotcrete that varies with the actual rock conditions encountered along the tunnel route.

As construction progresses, a waterproof membrane and the final cast in place concrete liner is constructed to finish the tunnel.

Where is the water for the third tunnel going to come from?

The use of water flowing out of Lake Erie is governed by the 1950 Niagara Treaty (and subsequent notes) between the Governments of Canada and the United States. The Treaty requires the following flows to go over the Falls:

Tourist Flow = 2,832 cubic meters per second each April 1 - September 15 (8:00am to 10:00pm) and September 15 - October 31 (8:00am to 8:00pm)

Non-tourist Flow = 1,416 cubic metres per second during all other hours.

The International Niagara Committee was established under the Treaty to verify that the minimum flow over the Falls is met and to report on the withdrawal and use of water for hydroelectric generation.

The goal of the Treaty was to apportion water flowing from Lake Erie to Lake Ontario in a manner that balanced tourist requirements for scenic water with the water needed to operate the Canadian and US power plants.

The long term average Niagara River flow is about 6,000 cubic metres per second. Over the course of a year, on average about one third flows over the Falls for scenic purposes and about two thirds is available for power generation, split equally between Canada (OPG) and the United States (New York Power Authority).

The Niagara River flow available to Canada for power generation is currently often greater than OPG’s existing diversion capability of 1,800 cubic metres per second, resulting in the use of some of the excess water in the New York Power Authority (NYPA) units through an unit rental agreement, or extra flow over the Falls.

The water in the new tunnel will be some of this excess Falls flow or rental flow.

What will be the effect on water flowing over the falls?
The new tunnel will enable OPG to better utilize Niagara River water to generate clean, renewable electricity. Excess water above and beyond what is required for tourism is now “spilling” over the Falls some of the time. The new tunnel will divert that water for much needed electricity.

The amount of water going over the Falls now, and in future will be in compliance with the Treaty requirements.

Where will the tunnel run?

The route of the new tunnel is mainly below the two existing OPG diversion tunnels which have been there since the 1950s. For much of its route the new tunnel is about 140 m below the ground surface.

The tunnel runs from an intake located near the international control dam, upriver of the Falls, to the outlet, located near the Sir Adam Beck generating stations. For the most part, the tunnels follow a route that runs just to the west of Stanley Avenue under the City of Niagara Falls, Ontario.

Click here to view the route the tunnel will take.

Where is the Tunnel Boring Machine (TBM) Big Becky right now?

Big Becky is fully underground, working its way down an 8 per cent grade towards the Queenston shale, where it will level out.

Once the TBM levels out in the Queenston shale rock formation, about 140 m below the ground surface, progress is expected to average about 15 m per day.

The first 1,500 m of its journey is expected to be the slowest part of the tunnel bore. In this first part of the journey, TBM commissioning and worker training and familiarization takes place. The changing rock conditions, and groundwater inflow also present challenges that make progress slow.

When did the project begin, and when will it be complete?
In 2004 the Ontario government endorsed OPG’s Board decision to proceed with the project. Prior to that a lot of planning had been done.

Construction at the outlet began in September 2005. Construction at the intake, near the existing International Niagara Control Works, started in January 2006. The actual boring of the tunnel began on September 1, 2006. Construction is expected to be complete in 2010.

Who is building the tunnel?
In 2005, through a competitive international proposal process Strabag AG, an Austrian company, was selected to design and construct the project.

Strabag hires its construction workers through the local trades union halls. Strabag has engaged several Ontario subcontractors for specific construction work on the tunnel intake and tunnel outlet.

OPG has also engaged Hatch Mott MacDonald, with Hatch Energy, as Owner’s Representative, to review and monitor the contractor’s design and construction activities.

How is the project being funded?

The Province of Ontario has committed to provide OPG with the required financing for the project and the costs will be recovered through the regulated price for future electricity generation from OPG’s Sir Adam Beck generating stations.