Thursday, December 20, 2012

3D Thursday: 3D through the aqueduct, part 2 of 2

Today's 3D blog post continues our journey through LeBreton Flats' aqueduct, which began with part 1 last Thursday.

We left off last time on the outcropping over the bridges spanning Lloyd Street and Lett Street, just north of where the Transitway turns toward Albert Street. The Claridge condos are visible in the background for reference. In the foreground is the top of the second, newer aqueduct ("newer" being 1908) under what used to be Ottawa Street:

To further get our bearings, here's a winter shot from atop the cliff at the North end of Bronson Avenue, taken in March 2011 (I had a 3D photo of a similar angle at the top of Part 1). Here we can see the Lloyd-Lett bridge at the upper-left, the grassy area past the stone building. J.R. Booth's trains ran diagonally over this bridge, then through the 20' wide curved alignment along the aqueduct's far embankment, just behind the stone building. Beyond the bridge, we can see the aqueduct, following roughly along the Transitway, before the two split, with the aqaueduct heading underground toward the river on the right, and the Transitway heading left toward Bayview. In the foreground we can see Pooley's Bridge, which was narrowed significantly during its restoration in 2001. More on that below.

Here's a map of the area from an RMOC report on the rehabilitation of the bridges. It identifies the bridges we've talked about so far—the Canada Central railway bridge, the Broad Street Bridge, the Booth Street bridge, as well as the wide span that comprises the Lloyd Street bridge, Lett Street bridge, and Booth's Grand Trunk Railway bridge. I believe the dashed lines indicate feedermains, but the water system was completely redone in the 2000s.

On the downstream side of the Lett Street bridge, we can see the water coming out from under the Ottawa Street aqueduct. Beyond it is the original aqueduct, whose stone arch is obscured. This photo was taken during a Jane's Walk by David Jeanes on the railway history of LeBreton Flats, where I learned much of the information imparted in these posts. We're looking west-ish; behind the crowd are some buses on the Transitway, and behind them is the top of the City Centre building. At the far right are some of the buildings at Tunney's Pasture.

Get your 3D glasses out for the next few photos! Here's a shot looking in pretty much the opposite direction from the previous one, from atop the second aqueduct. Obviously, since there's no water in it, it was taken at a different time of year—mid-August, in fact. Beneath us is a rusted out old iron water main, and at the right is the feedermain currently in use, which was installed—or at least upgraded—sometime between 2005 and 2007 (as evidenced by appearance of the rocky embankment on the right in aerial photos between those dates, and visible in Bing Maps' aerial views).

This leads to the Fleet Street Water Pumping Station, which pumps water that comes through this pipe from the Lemieux Island water filtration plant. It is powered by the water that flows through the aqueduct. The Lemieux Island plant and the Britannia plant are Ottawa's only water filtration plants, meaning that the water in the east and south ends of the facility have to pass through here (indeed, a major component of the Bronson Avenue reconstruction involved chiseling through 18 feet of rock to embed massive feedermains to feed the thirsty south end of the city. Sticking up behind it are the Juliana Apartments and the Gardens condominiums, built relatively recently by Charlesfort.

In this photo, we can see the caissons that probably used to separate the two aqueducts in a previous configuration, and on the right, the old iron pipes. If you don't have your 3D glasses on, you're really missing out! Poking out in the far upper-left are the Stonecliffe Apartments, and Bronson Place behind it.

In the same position, turning downstream, we see the caissons and sluice valves that control the intake into the station and the runoff leading under Pooley's Bridge.

Then as we look straight down into the nearer channel, we see a bunch of old ironwork. The end of the pipe has a big hole in it. At left, there's an old iron valve; I presume an intake valve. Various items have been thrown into the channel as well.

When we walk over Pooley's Bridge, we see the old front of the pumping station, or Water Works, as it was known when this carving was installed to announce the 1888 expansion of the building.

There is an excellent, extensive (albeit 2D) URBSite post on the Fleet Street water pumping station. The station was restored in 1983, with Barry Padolsky's firm serving as the architect.

The bracing on the left was installed for some work going on in the site earlier this year, and is still there today. I'm not sure exactly what work is going on, or if that bracing will remain there for the LRT tunnel digging. This photo is also taken from Pooley's bridge, whose railings can be seen in the foreground.

Looking at the bridge itself from further downstream, we can see the former abutments of the bridge, which used to be two lanes wide. It is the oldest stone-arch bridge in Ottawa, and the second oldest in Ontario.

When the bridge was restored in 2001, Padolsky was involved also.

Apparently in 1999 the City's Local Architectural Conservation Advisory Committee (LACAC, later OBHAC, now in limbo) rejected a request from the RMOC to demolish the remainder upon renovation, though obviously that recommendation was not given priority. On page 6 of that report, there's a copy of the Statement of Reason for Designation that accompanied the bridge's heritage designation in 1994.

It was reduced to its current width for pedestrian and cyclist use as part of its rehabilitation, described in the RMOC report I mentioned previously. Various options were presented to preserve the bridge in various levels of completeness, with alternative 3B being the chosen one, as shown in the diagram below from that report:

During the construction of the LeBreton Flats condos by Claridge, fences were installed across Pooley's Bridge to close it off along with the rest of the construction site. Despite this, it was a key connection for Bluesfest patrons, who simply climbed over the fence. The reopening of the bridge was noted on West Side Action in 2009.

Beyond Pooley's bridge, downstream of the Fleet Street pumping station, is the station's tailrace, which Google defines as a "fast-flowing stretch of a river or stream below a dam or water mill".

Here, with the tailrace drained, we can see two of the tunnels where the water comes out on the left side of the channel. In the foreground is one of the concrete-topped piers of Pooley's Bridge.

While "tailrace" is a generic term, I've only ever heard this one referred to locally as "the" tailrace, likely due to its use as a kayaking facility.

The May 1999 RMOC report, page 12, has more information on the tailrace: "The tailrace north of Pooley’s Bridge is a designated heritage facility and a Class 1 Fish Habitat. It is also considered to be a World Class Olympic training facility by local kayaking groups."

At some point since then, between 2002 and 2005 according to the City's aerial maps, there were some "Emergency measures to stabilize the banks of the tailrace", as described (with photos) by the contractors who did the work, Dufresne Piling Company.

And when the tailrace is filled with water, the kayakers appear! This was actually one of the first 3D photos I took, and the last one of this post:

If you didn't already, check out the URBSite post on the Fleet Street pumping station, which has a lot more history on this facility.

I've discovered a number of historic maps and technical drawings for the aqeuduct and the bridges crossing it, unfortunately too late to incorporate into this post. With any luck, I'll be able to put it together for a post on a non-3D day.

[Tune in on Thursdays at noon for a new 3D image. View the 3D label for other posts with 3D images]


  1. Very valuable documentation, fascinating insights. Thanks

  2. I read somewhere that the canal was originally to flow down Preston street (marshy lowland) after the Dow's swamp area was dammed up. There is evidence against Lord Dalhousie's claims that the canal route was changed due to Lebreton's land speculation.

    Thus the opportunity to build a canal and locks to connect the upper and lower Ottawa Rivers was lost

    These locks would have been a first step to connect the Ottawa R with the Great Lakes via a Northern Canal.

    Champlain portaged to the Mattawa R. into L. Nippissing then to great lakes via French R.

    The Northern Canal project was set to go in 1850's by Upper Canada Parliament according to R.W. Scott in his "Recollections of Bytown". One can download this book, an eye opening read