Downtown Rapid Transit Expansion Study

[Woodbridge_Heights]

Whatever route is chosen for a DRL subway, I believe a transfer station at Queen-Roncesvalles is absolutely essential to both relieve pressure at Union Station and provide better transit service for Parkdale and the Western Waterfront.

A station here would be able to connect the following services:
-GO Lakeshore Trains
-TTC DRL Subway
-TTC 504/501 Streetcar
-Waterfront West LRT*
-GO Bus
-Greyhound Bus
(* if constructed)

Here's my concept of what a Sunnyside mobility hub could look like:

I agree with this. This area could become a significant node of development with so much transit service (if it's built). Hell I wonder if you could convince VIA to return service to this area with an auxillary station here.

 

[gweed123]

Whatever route is chosen for a DRL subway, I believe a transfer station at Queen-Roncesvalles is absolutely essential to both relieve pressure at Union Station and provide better transit service for Parkdale and the Western Waterfront.

A station here would be able to connect the following services:
-GO Lakeshore Trains
-TTC DRL Subway
-TTC 504/501 Streetcar
-Waterfront West LRT*
-GO Bus
-Greyhound Bus
(* if constructed)

Here's my concept of what a Sunnyside mobility hub could look like:

I like this. Personally though, I'd prefer to see the DRL run along Lake Shore out to the Ex, and then up Dufferin. That way, it would create an even bigger transit hub at Queen & Dufferin, with 3 GO lines, the DRL, and the terminus of the WWLRT, as well as the Queen streetcar (which can eventually also be put underground as an extension of the WWLRT).

Of course, this certainly does not exclude the possibility of the Roncesvalles hub as well (minus the DRL of course). I would like to see both of them built.

 

[nfitz]

There are a few parts of the TTC subway which are submerged including a few stations which are adjacent to or partially under underground rivers.

Underground rivers bring up visions of caverns with water flowing in them. There are no such thing in Toronto as far as I know.

In this temperate climate, there is groundwater anywhere you dig, often near surface - and under very wet conditions, pretty much at the surface, pretty much anywhere in Toronto. Most subway tunnels will be below the natural water table.

This isn't unusual, and it's unfortunate that the level of ignorance on the issue is so high, that the TTC writing "water table" for an excuse that the project is over budget gets a rubber stamp from the commission.

It's almost enough to make you think that "water table" is the codework for the kickbacks (I don't think that BTW).

 

[rbt]

Underground rivers bring up visions of caverns with water flowing in them. There are no such thing in Toronto as far as I know.

The watertable isn't really level with the lake; it has high spots and low spots and the water will flow from high to low faster through loose/sandy soils than through clay.

 

[Fred.S]

Whatever route is chosen for a DRL subway, I believe a transfer station at Queen-Roncesvalles is absolutely essential to both relieve pressure at Union Station and provide better transit service for Parkdale and the Western Waterfront.

A station here would be able to connect the following services:
-GO Lakeshore Trains
-TTC DRL Subway
-TTC 504/501 Streetcar
-Waterfront West LRT*
-GO Bus
-Greyhound Bus
(* if constructed)

Here's my concept of what a Sunnyside mobility hub could look like:

This is an excellent plan, and I always thought this area would make a great transit hub. I believe it was a pretty big hub decades ago when there was a Sunnyside train station. The streetcar land could be rebuilt to include the station and be a streetcar terminal, is much of it would need renovating for the new streetcars anyway.

Even without the WWLRT, it could then become a logical western terminal for the 501, and west from there the line could become the 507 or something, making both routes much more reliable.

 

[Tulse]

Underground rivers bring up visions of caverns with water flowing in them.

Those may be the visions you have, but that isn't what is meant here. Anywhere a more permeable layer (such as sand or gravel) lays on top of a less permeable layer (such as bedrock), water can flow through it, just as in a riverbed. There are various places in Toronto where this phenomenon can be seen, such as the Laurentian River under High Park.

 

[nfitz]

The watertable isn't really level with the lake.

No it isn't. The streams in the city would represent the water table where at those locations, and the water table would then be a bit higher than the streams nearby.

The watertable is a lot closer to being level with the groundsurface, than it is the lake. Of course, if your right next to a ravine, the water is going to be a lot deeper than if your not near one ...

It's the permeability of the soils that's the big issue.

Though there aren't many big surprises. The constant surprising water tables we keep seeing cited in TTC reports demonstrate gross incompetence more often that not.

Those may be the visions you have, but that isn't what is meant here. Anywhere a more permeable layer (such as sand or gravel) lays on top of a less permeable layer (such as bedrock), water can flow through it, just as in a riverbed. There are various places in Toronto where this phenomenon can be seen, such as the Laurentian River under High Park.

True ... but only one who knew what they were talking about wouldn't refer to such a feature as a "river". It's an aquifer.

 

[Tulse]

only one who knew what they were talking about wouldn't refer to such a feature as a "river". It's an aquifer.

So you're objecting to the label, and not to the fact that these things are a concern for underground construction?

 

[jamincan]

True ... but only one who knew what they were talking about wouldn't refer to such a feature as a "river". It's an aquifer.

That's simply not true. Hydrogeologists study underground rivers all the time, and refer to them as such.

Referring to an underground river as an aquifer, while correct, is a bit like referring to a pond as a body of water. An underground river is an aquifer by definition, just as a pond is a body of water. An aquifer is not necessarily an underground river though, just as a body of water is not necessarily a pond.

 

[nfitz]

So you're objecting to the label, and not to the fact that these things are a concern for underground construction?

I'm pointing out the the label over-dramatizes the situation. Highly permeable materials are certainly a concern, but certainly not insurmountable or even unusual - which I think was rbt's original point. The correctly selected TBM would go through a highly productive aquifer relatively easily.

That's simply not true. Hydrogeologists study underground rivers all the time, and refer to them as such.

As a practising hydrogeologist I'd disagree with that, at least for aquifers the coarse-grained materials we see in Toronto. Perhaps in Kentucky where you have huge caverns in limestone. Perhaps you could point out some examples of this in the literature, such as in "Ground Water" - http://www.ngwa.org/Professional-Resources/publications/GW/Pages/default.aspx

An underground river is an aquifer by definition

While this might be true, I can't think of any examples of such a feature in the GTA. And an aquifer is not an underground river.

 

[Woodbridge_Heights]

This is an excellent plan, and I always thought this area would make a great transit hub. I believe it was a pretty big hub decades ago when there was a Sunnyside train station. The streetcar land could be rebuilt to include the station and be a streetcar terminal, is much of it would need renovating for the new streetcars anyway.

Even without the WWLRT, it could then become a logical western terminal for the 501, and west from there the line could become the 507 or something, making both routes much more reliable.

And I might add. With Dundas West (Dundas and Bloor) already earmarked as a growth hub, if we allow this area to become a hub then Roncesvales could conceivably become a pretty significant stretch of road. With 3 Go lines, 2 potential subways, 4 potentially Streetcar lines and High Park nearby. It could really become another satellite downtown. All that is required is the drive, and desire to really grow the area of Roncy.

 

[jamincan]

Underground rivers do only seem to be associated with karst topography. You don't really have to travel all the way to Kentucky to encounter it either. I know that there have been underground rivers which have been traced and partially explored on the Bruce Peninsula (and wouldn't be surprised to find them elsewhere along the escarpment). That's obviously not relevant in the case of Toronto though. It has also been used colloquially outside that context in some unique cases (Rio Hamza for example).

More to the point though, I would think that excavating into or above a confined aquifer (which this Laurentian River valley seems to be) would increase the cost of construction. I would hope that they do the preliminary work before excavating, but I don't think it is unreasonable to find something unexpected after the project has been approved.

 

[nfitz]

Underground rivers do only seem to be associated with karst topography. You don't really have to travel all the way to Kentucky to encounter it either. I know that there have been underground rivers which have been traced and partially explored on the Bruce Peninsula (and wouldn't be surprised to find them elsewhere along the escarpment).

You could get something like that above the Escarpment ... though any features I'm aware of are very very short, or aren't really bigger than a finger, rather than a subway tunnel.

More to the point though, I would think that excavating into or above a confined aquifer (which this Laurentian River valley seems to be) would increase the cost of construction. I would hope that they do the preliminary work before excavating, but I don't think it is unreasonable to find something unexpected after the project has been approved.

It would add to the costs, though there's very few confined aquifers in Toronto with any significant upwards gradients. And there's no surprises, as they install large numbers of wells before the project is approved. There's few real surprises, unless your consultant is either incompetent or ignorant (and I'd argue that the latter is evidence of the former).

 

[Woodbridge_Heights]

I think it's important also to differentiate between underground aquifers (or whatever the term is) and rivers and streams which had been filled in and/or incorporated into the City's water system. Contrast Garrison creek and it's fate with the Laurentian valley in High Park. Visit www.lostrivers.ca for information on things like Garrison creek. I imagine both present their own unique challenges.

 

[Johnny Au]

Castle Frank Brook flows above the subway along the southern half of Cedarvale Park (in fact, Castle Frank Brook is exposed there) and the subway there is cut-and-cover.