Skip to Content

Niagara Tunnel Project

Building the Niagara Tunnel was an unprecedented feat of engineering to divert water from the Niagara River and carry it downstream to the Sir Adam Beck Generating stations.

See how OPG worked with key partners to create a project for Ontario's future.

Engineering future energy production

For Ontario Power Generation, the Niagara Tunnel is a source of pride not only as an engineering feat but also as a practical clean energy solution for meeting Ontario's electricity needs.

In May 2011, the largest hard rock tunnel boring machine in the world finished drilling a massive tunnel deep beneath the City of Niagara Falls. The tunnel was filled with water in March 2013 and now provides additional water to generate more clean, renewable electricity at the Sir Adam Beck stations.

Tunnel facts

12.7 Metres


10.2 Kilometres


500 m³/second

Water diverted

160,000 Homes


Defining the flow of production

The 1950 Niagara Treaty establishes the terms under which Canada and the United States share the Niagara River waters to generate electricity while also maintaining the scenic beauty of the world-famous horseshoe falls.

Over the course of a year, about one-third of the water flowing from Lake Erie must be sent over the Falls — more during the summer Tourist season — while the remaining two-thirds is split evenly between OPG and the New York Power Authority for power generation.

Creating new paths to power

Since the Sir Adam Beck generating stations are not built directly at the Falls like many other hydroelectric stations, the water they use to generate power must be diverted to them through canals and diversion tunnels.

Before the new tunnel, these passages proved insufficient to handle Ontario’s full share of water. Now with the new tunnel in place, more water is available for OPG to generate clean, renewable electricity — enough to power an additional 160,000 homes each year.