How about a tunnel, then demolish Gardiner?

By Stig Harvor –

The Great Debate on the future of the elevated Gardiner Expressway has yet to begin.

A lot of studies and a lot of noise have been provoked over the years by supporters and opponents of this formidable and ugly concrete belt that cuts our city off from its lake.

The debate was rekindled some four years ago by federal, provincial and municipal governments, when they created the Toronto Waterfront Revitalization Corp. (TWRC) to was to plan and hopefully implement a new, grand vision for the now-abandoned and derelict industrial harbour area.

TWRC boldly proposed tearing down the elevated Gardiner. The western portion would be buried in a land tunnel from Strachan Ave. at the CNE almost to Spadina. It would then continue as a wide surface boulevard to the mouth of the Don River.

Since then no official TWRC plans have been released. But studies have continued. These studies and ideas were to have been revealed last year. The word now is that publication will not occur until the very limited powers of the TWRC are enlarged and better defined so that the corporation can proceed with its work.

To tunnel under or beside the existing Gardiner is a very complex and messy job. It requires maintaining the stability and safety of the massive concrete structure and the many large buildings that have sprung up nearby. It also involves expensive changes to existing underground municipal and other services in the path of the tunnel.

The nightmare costs, delays and problems of Boston’s centretown “Big Dig” are sometimes evoked as a warning. The Gardiner situation is not quite as complicated but is still an unpredictable challenge.

Rather than a land tunnel, a tunnel under the lake has been suggested over the years. The idea was briefly discussed again this spring when the preliminary feasibility study for a Toronto World’s Fair in 2015 was published. The study mentioned the need for a tunnel limited to public transit to link the proposed divided fair site of the Island airport and the Portlands.

Earlier attempts to link a general traffic tunnel to some main Downtown feeder streets raised major problems both for the tunnel and the waterfront. A simple solution would be to build the harbour tunnel as an exclusive through-route with no connection to Downtown.

It has been estimated that up to 40% of Gardiner traffic bypasses Downtown over a 24-hour day. Since the percentage is much lower at rush hour, the positive effect on Downtown traffic would vary greatly during the day.

The most rational way to avoid traffic gridlock would, of course, be to lure suburban commuters out of their cars and into efficient and readily available public transit. But such a solution will take a long time to implement in our car-dominated culture.

Ideas of a harbour tunnel have in the past always been dismissed as far too expensive. Yet techniques of pre-fabricated, underwater tunnels have evolved in Europe to the point where many such tunnels have been built.

Complete concrete tunnel sections are built on land. They are then floated and sunk in place in a bottom trench one after another like beads on a necklace. They are sealed together and made ready for traffic.

Oslo, the capital city of Norway, already has built eight land traffic tunnels and is starting on a pre-fabricated harbour tunnel. Such underwater tunnels are expensive. The new Oslo tunnel is estimated to cost around $400,000 per metre based on Norwegian prices.

It should be noted that prices in Norway, like in Europe today, are much higher than in Canada. Oslo now has the dubious distinction of being the most expensive city in the world.

Say we consider a Toronto harbour tunnel to stretch from Bathurst Ave. to Cherry St. where it would join up with the existing elevated Gardiner across the re-naturalized mouth of the Don River. It is a distance of about 4,000 metres. Such a tunnel would then cost very roughly $1.6 billion at Oslo prices. How much less it would cost in Toronto is hard to say. In any case, it is a lot of money.

Now consider the savings. The Gardiner and Lakeshore Boulevard would stay in place until the harbour tunnel is finished in a matter of years. Only then would the Gardiner be removed and replaced by surface roads.

This would take far less time than the many years of traffic chaos caused by building the land tunnel which removes Lakeshore Blvd. during construction. Some of the considerable public land now occupied by the Gardiner, its long ramps and parts of Lakeshore Blvd. could also be sold for development.

All changes to the Gardiner create unavoidable hardship for the public and business. The shorter the hardship, the less the overall cost to everyone. When we talk of costs of changes to the Gardiner, we must compare the overall cost to our city and not deal with construction costs only. This is a complex calculation but a necessary one if we are to look at the real costs of various alternatives.

The city has proposed a variation of the TWRC land tunnel plan by extending the tunnel to Jarvis St. Traffic east of Jarvis would be channeled onto an elevated earth berm beside the existing railway berm before rejoining the existing Gardiner around Cherry St. crossing the Don River.

Why end the tunnel at Jarvis? A more sensible solution would be to extend it to Cherry St. This would interfere less with the livability of the adjoining, attractive St. Lawrence Neighbourhood and the future West Don Lands community.

Have any of the TWRC or city studies still under wraps considered a harbour tunnel? We are still awaiting an answer.