Plans are advancing for a new streetcar line that will serve Toronto's waterfront.

This will be a missing link in the city's transit network that has remained planned but unbuilt for decades.

The planned Waterfront East LRT (WELRT) — approved in 2018 — will run from Union Station south to the foot of Bay Street, east along Queens Quay to the Distillery Loop at Cherry Street, before turning south to serve the western Port Lands area.

The City, in partnership with Waterfront Toronto and the TTC, is conducting a study to complete the preliminary design and engineering phase of the project, and have released new visuals depicting what the line will look like upon completion.

This plan involves replacement of the existing approximately 540-metre long tunnel running under Bay Street from Queens Quay Station to Union Station, which was completed in 1990 to connect subway riders with the Harbourfront streetcar.

By 2041, over 40,000 people are estimated to use the Union Station streetcar platform per day, busier than many of the city's subways stations, and the current infrastructure has been deemed inadequate for current and projected future service demands.

To better serve the city in the future and accommodate the projected ridership levels, the tunnel is destined to be expanded and transformed with new expanded multi-directional platforms, station entrance connections, fire ventilation systems, and an underground electrical substation.

Four platforms would be created in the current streetcar tunnel, while the current circular platform serving streetcar traffic at Union would live on as a turning loop.

There is also new information about how the line's underground infrastructure would be constructed. The cut-and-cover excavation method is planned for new streetcar portals on Bay Street and Queens Quay.

This method is much most cost-effective than the tunnel boring machines used on other below-grade projects, at the price of more surface-level disruption.

The City warns that, during construction, at least one lane traffic will be maintained in each direction. As a result of the surface-level construction, streetcar service is to be halted for the duration of work, replaced with buses.

A report on the project will be delivered to City Council in June 2023, and the City is currently seeking public feedback on the project.

A virtual public consultation was held on April 5, and the City is now following up with a survey seeking public feedback on the project.