A rare view of Rivière St. Pierre, 1956, location unknown.

I recently stumbled across a peculiar old map for the island of Montreal showing a rather fantastic depiction of the island’s former creeks and lakes. It’s unlike any other map of the island I’ve ever come across. There’s no publication date printed on it, but given its author, Aristide Beaugrand-Champagne, it likely dates from the 1920s.

Beaugrand-Champagne was one of the city’s  architects and historians. He was also the originator of the idea that Jacques Cartier first arrived in Montreal from the north via Riviere Des Prairies rather than the South. Though it had its share of proponents, it was, and still is a controversial theory. This point of Cartier’s landing is highlighted on his map along the north shore, in Sault Au Ricollet.

During his studies, Beaugrand-Champagne paid special attention to the island’s former watercourses. In doing so, he came to the conclusion that the Iroquois village of Hochelaga was once situated in Outremont rather than in an area contained somewhere within the McGill University campus— another controversial theory for its time.

Anyway, with that mini-history lesson is out of the way. Here’s Monsieur Beaugrand-Champagne’s pièce de résistance. Clicking on the map for the larger view is recommended for this one.

Beaugrand-Champagne's map illustrating the island's topgography and hyrdrology between 1542 and 1642.

It’s hard to tell how much of this map is based on Beaugrand-Champagne’s knowledge of the island’s geography and how much of it is based on his imagination or even cultural bias. Any illustration attempting to show what the island looked like more than a couple of centuries ago is bound to have a certain degree of inaccuracy, and this one is no different.

For a map intended to show what the island looked like during the 16th century, the large lakes at the eastern end of the island seem inconceivable.

However, a surficial geology map from 1975 reveals these same areas to consist mostly of peat- a sign that, at the very least, there was once marshland there. One of these areas contains the recently developed complex of subdivisions named Anjou Sur La Lac. Of course, the “lac” that exists today are entirely artificial creations.

Detail of map from 1975 illustrating the east island's surface geology. The portions highlighed in purple represent areas high in peat.

While the depiction of former lakes and marshland might be accurate, the map isn’t without its flaws. Ruisseau Molson is mislabeled as Ruisseau Migeon which was actually situated further west. The general tangle of lines formed by some of the creeks bear no resemblance to either the earliest maps of the island from the 1700s or the more detailed cadastral  plans that would start to show up a century later. The way each system conveniently connects to the next also seems a bit unnatural and makes it less than convincing.

Besides Beaugrand-Champagne’s map, there’s little else out there that illustrates the island’s former hydrology. There are a couple of old maps that illustrate certain drainage boundaries, but there’s really only one other option out there if ever you want to know exactly what flowed where.

Detail from the map entitled Les Ruisseux et Fosses published in 1955.

In 1955, Montreal’s Water and Sanitation department published a map entitled “Les Ruisseux et Fosses.” Despite its age, it’s what they’ll give you at the City’s Planning Department if ever you go in and ask for a map of Montreal’s creeks. These same paths show up as dotted lines on the city’s sewer maps, and I suspect it’s what developers will refer to when deciding where they should and shouldn’t build certain things.

Not surprisingly, a lot of it contradicts other maps published over the past few centuries and its unclear what source some paths were based on. While a good deal of it does seem to be accurate, especially the areas surrounding downtown Montreal, some of it seems either too complex or not complex enough. Nevertheless, it’s the one I’ve chosen to use as foundation for my own interactive map. While I’m tempted to go through it and clean up a few things, it would be a difficult task to figure out just what should be changed.

Take Ruisseau Glen, a small tributary of Riviere St. Pierre that once ran just east of the Turcot interchange. Given the number of variations of its path from map to map, it’s hard to know which one is the most accurate.

Which one is it? Variations of Ruisseau Glen's path from multiple maps dating from the 1700s to 1956.

Another problem with almost all of these maps (my own included) is that there’s no indication as to how wide these watercourses were and how much water actually flowed through them. One might assume that a line represents a creek when in reality it may have just been the smallest of springs. Even one of the city’s more famous lost “rivers”, Riviere St. Martin is shown on one map from the 1700s with “This Rivulet is sometimes dry” written below it.

Detail of map from 1760 showing a portion of Riviere St-Martin flowing behind the original fortifications of Montreal.

Whether its lack of water was caused by Montreal’s development or from natural causes is unknown. Similarly, Riviere St-Pierre, which by some accounts was quite broad at the points where it emptied into the St. Lawrence, was likely no larger than a small brook a short distance inland.

Even the portions that did appear to be deeper or wider were the result of human engineering as was the case in Verdun and Cote St. Paul where attempts were made to use the creek as an open tailrace for the city’s waterworks’ engines. Additional modifications were likely also made to prevent the sort of flooding recorded in an 1878 issue of The Montreal Daily Witness.

Article from the Montreal Daily Witness, June 10th, 1878.

Unfortunately, since much of the landscape where these watercourses once were has been leveled and built over, we don’t have much to go by. With but a few exceptions, we can no longer see the contour of the land where water once flowed. The natural vegetation surrounding them has been uprooted.

With these visual clues scrubbed from the landscape, we can begin to look underground for clues, but it’s impossible to gauge how much of what flows through the sewers comes from the original network of creeks and how much is just wastewater.

Depiction of the City of Montreal's collector sewer system in 1962. By this point most of the creeks in this area of the island had dissapeared.

Instead we are left with a few (very few) photographs, written descriptions and a bit of oral history from those old enough to remember their remnants. These  systems didn’t simply disappear when they were covered over, though. Instead, they just underwent a transformation.

I’d like to think that my experiences and recollections of following these systems through the sewers are just as much a part of their open-ended history. Despite the  fact that their paths now appear fixed and are easily traced, things will continue to change underground just as they did on the surface.

Pipes will be enlarged, made smaller or set deeper into the ground. Old lines will be removed and others will be added elsewhere. New maps will be drawn, photos will be taken and hopefully over the course of this ongoing evolution, more stories will continue to be told.

So far, most of my entries have dealt with Montreal’s sewers as its the one aspect of the underground that I’ve spent the most time exploring. During my time looking into that particular system it’s been hard to avoid the city’s waterworks, both during my time traveling around (and under) and at the City Archives. While the two systems serve entirely different purposes, they still share a few things in common and often intersect in a number of different ways.

While one can’t exactly travel through the waterworks system to the same extent that you can the sewers, there are still a number of different components that can be peered into and occasionally entered.

But before we do that, a little bit of history.

The roots of both networks can be traced back to the 1800s. The waterworks was established during the early 1800s and in turn encouraged the growth of the sewer system. As the water distribution network expanded, sewers became necessary in order to help get rid of it once consumed.

Public records also illustrate how the expansion of the sewer system might have inadvertently helped distribute water into areas that were previously dependent on wells.

English transcript of minutes from a meeting in 1905 involving Montreal's Health and Sanitation Department. Source: City Archives of Montreal

There are also reports of water pipes having been laid directly along the interiors of the sewers – a practice likely inspired by Paris – but I’ve yet to see such a thing in person. For the most part, the two systems generally stay out of each others way and for obvious reasons.

In regards to subjects already covered on this site, both systems also made use of Riviere St. Pierre, but for different purposes. The city’s first collector sewer relied on the river’s flow to take wastewater away from the city and out into the harbour. Likewise, the City’s first successful waterworks system used the Verdun arm of the river to dispose of the water passing through its system’s wheelhouse.

1861 plan of the Montreal waterworks. Water leaving the wheelhouse at the bottom left corner flowed into Riviere St Pierre. A section of the proposed tailrace channel that would eventually bypass the river can be seen in red. Source: Pistard Archives

A tailrace channel leading south to the St. Lawrence was later added as a substitute for the river. This passage can still be detected today by the straight stretch of Autoroute 15 that defines the west border of Verdun. Buried beneath this tract of land is the St. Pierre Collector sewer, which, much like the tailrace that preceded it, is used today to discharge excess water from the present day filtration plant.

Attempting to explain the history of the entire waterworks system would probably be a bit too much for one post so like I’ve been doing with Riviere St. Pierre, I’ll try and break things down into several posts starting with the aqueduct.

The Montreal aqueduct (or aqueduc, in French) is an open canal that runs a length of roughly 8 kms from LaSalle to Verdun. It’s hard to miss, but it’s also quite easy to forget about and take for granted. Unlike the nearby Lachine Canal, the aqueduct doesn’t have an abundance of picturesque buildings situated alongside it. It has its charms, but more often than not it seems to be more of an obstacle than an attraction.

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A bike path running along the canal’s south side was added during the 1980s, but the aqueduct itself is fenced off, for security reasons and to discourage people from using it for recreational purposes. For anyone following the news in Montreal lately, this public use VS water security aspect might sound familiar. Of course, it’s never too difficult to find an opening to be able to walk along its shore where you’ll often encounter people fishing.

The City of Montreal completed the aqueduct canal in 1856 under the direction of Thomas Keefer. It was designed to bring the “purest” water from the St. Lawrence River to a point where it could then be pumped up towards the central region of Montreal. At the time of its completion, there had already been fifty years worth of attempts by private companies to distribute water to various points across the city. All had failed for a number of different reasons.

The first effort began during the early 1800s. Using a system of wooden pipes, water from a creek (or “spring”) in Cote Des Neiges was transferred around the West side of Mount Royal and into two reservoirs situated in Montreal.  Given the small amount of water available from the source, it comes as no surprise that the scheme never quite worked out.

A later system brought in water straight from the city’s harbour, but was soon abandoned when it was realized that waste from the outlet of the William Collector sewer was making the water taste “foul.”

With a rapidly expanding population during the middle of the 1800s, a series of devastating fires, and the spread of industrialization, it was clear that a more comprehensive scheme to distribute water across the city was necessary.

The solution, as proposed by the city’s Chief Engineer Thomas C. Keefer in 1852, involved the aqueduct canal to convey what was found to be the most reliable and “pure” source of water from the St. Lawrence River.

The Lachine Canal was briefly considered as a source of water, but later rejected. One of the reasons was that it was thought its polluted water might be hazardous, not so much for people, but for the iron pipes to be used throughout the distribution system.

Plan of the aqueduct system in 1854 showing the path of the rising mains (red) which delivered water to the McTavish reservoir. This map also shows the proposed path of a tailrace channel exiting South of the entrance to the Lachine canal.

The entrance point of the aqueduct was first located at point further East. Today, the broad curve at the Lasalle end of Rue Champlain is attributable to the canal’s original path.

1911 map showing the old and new entrance points to the aqueduct. The bottom entrance was later filled in during the 1920s.

At both entrances, gates designed to regulate the flow of water and to keep ice and other debris from entering the entrance to the aqueduct.

Overlooking the Lasalle end of the aqueduct in Lasalle built during the 1920s. The building in the background was constructed at the same time and currently transfers water from the river to the Charles J. Desbaillets treatment station.

After water entered the aqueduct it was fed by gravity towards a single settling basin 4kms away which encouraged rock and other solids to fall to the bottom. This was the extent of purification at the time.

It would take decades before more substantial steps would be taken to ensure cleaner water. Even by 1878, the Superintendent of the Montreal Water Works preferred the “settling” process over filtration, stating that the water “looks a great deal worse than it is.” He further suggested that purer water could be obtained “with the aid of a small filter in the house” and that boiling it was a good way of “removing all deleterious ingredients.”

Adjacent to the settling basin sat the wheelhouse containing water wheels which powered a pumping station used to force the water uphill through a series of underground iron pipes towards the McTavish reservoir- a good four kilometers away.

1913 map overlay of the Atwater treatment plant property. Click to launch the Google Maps version. A slider at the top controls the opacity between the two layers.

By the 1920s, everything on the property had been either decommissioned or demolished and replaced with a newer purification plant that could be operated using electricity. It also abandoned the settling basin in favour of  a series of filtration galleries. This same arrangement is what can be found on the property adjacent to the end of the aqueduct today, albeit with a few upgrades that have since been added.

As for the aqueduct itself, not much has changed since its conception. It’s both wider and deeper than the original, having been altered over the years to meet changing needs. For the most part, its alterations were made in order to increase the horsepower available to hydraulic (and steam) equipment. Given that the current system is now powered by electricity it is likely far larger than it needs to be.

It seems there were also grander plans to use the canal for purposes other than water distribution that were never fully realized. As the city’s chief engineer C. J. Desbaillets pointed out in 1931, “The reason for this large canal is that ultimately the city will develop power from it which will be used for various purposes by the municipal authorities.”

Despite these ambitions, the aqueduct found today is still only used to help transfer potable water using the same principles that were established in its infancy. The methods of purification have changed, and many of the system’s components have been upgraded over time, but the methods used to get water from the St. Lawrence River to downtown Montreal have remained more or less the same.

Up next: Following the waterworks system underground.

At the mouth of Riviere St. Pierre during the early stages of Montreal in 1700.

In a golf course to the west of downtown Montreal, you’ll find the last remaining portion of Rivière Saint-Pierre that still exists above ground. 200 meters are all that are left of a river system that once flowed freely over the landscape. The rest of it’s been retrofitted into the city’s sewer system or lost entirely. This one brief open stretch is found at the river’s upper reaches, in the town of Montreal Ouest. If one were to follow the river’s original path downstream from here, fifteen kilometers later you’d find yourself standing at the tip of Pointe à Callière. It was here, where the river spilled out into the open waters of the St. Lawrence that the city of Montreal first began.

“Here I examined the country very carefully, but after looking everywhere found no spot more suitable than a little place to which pinnaces and shallops can ascend. And near this Place Royale, there is a small river, which leads to some distance into the interior, alongside which are more than sixty arpents of land, which have been cleared and are now like meadow, where one might sow grain and do gardening. [...] So, having examined very carefully and found this spot to be one of the finest on this river, I ordered the trees of the Place Royale to be cut down and cleared off, in order to level the ground and make it ready for building.”

- Samuel de Champlain, 1611

Much has already been written about the origins of Montreal so I won’t waste space explaining it in detail here. Here is the Coles Notes version: while native Indians had already made use of the land surrounding the mouth of Rivière St. Pierre for centuries, Samuel de Champlain was the first French explorer to take notice of the area’s potential for a permanent development. In 1611, he made note of the land and came to the conclusion that its conditions were favourable for establishing a fur trade outpost. By the year 1642 the village of Montreal was officially founded.

Rivière (and Lac) St-Pierre shown with proposed alterations, 1739.

Over the course of Montreal’s evolution, Rivière Saint-Pierre (or the Petite Rivière Saint-Pierre) has slowly been altered and effectively removed by man. By the early 1700s, attempts were already being made to rework the river, the goal being to create a passage to bypass the unnavigable waters of the Lachine rapids. Its plump middle stretch (often referred to as Lac Aux Loutres), would soon diminish in size, perhaps as a result of the Saint-Gabriel canal project which attempted to draw water from the lake to supply the town mill.

Approximate path of river, circa 1800. View Larger Map

The first phase of covering the river occurred in 1832 with the creation of the William Collector; a vaulted stone conduit that covered the initial 350 meters. The river had long been used as a convenient dumping ground for both human waste and anything else that needed to be disposed of. As a result its waters grew increasingly foul to the point where it eventually started to become an issue for public health. Covering this portion of the river was to be the beginning of an “of sight, out of mind” policy towards waste disposal that still exists today.

From there, the river’s westward portions would gradually suffer a similar fate, but not before further straightening, dredging or repositioning depending on what stood in its way. Following its course on maps is often confusing as its position changes frequently, often vanishing on one map, only to reappear later on another. Even more frustrating are the older maps, which are less than precise and display a certain amount of creative license (or guesswork) on behalf of their cartographers.

As the city became more industrialized during the mid to late 1800s, the river began to serve several functions. The city’s waterworks company created a tailrace for its wheelhouse using a portion of the river in Verdun, while further north, leather tanneries made use of its flow to help drive steam engines. More often than not, though, the river was quickly becoming integrated with the large-scale sewer system that was starting to be developed.

Expanding the riverbed to make way for twin collector sewers in Cote St. Paul (?), 1933

By the mid 1930s roughly a third of the river had now disappeared to the sewers system, much of that lost with the construction of the St-Pierre collectors. Today, these two 15’ and 17’ concrete conduits collect the majority of wastewater from Westmount to outlying communities as far west as Cote St Luc. The two sewers bring the flow towards a point in Verdun. From there everything is funneled down into the southeastern interceptor where it begins its long journey towards the island’s wastewater treatment plant at the East end of the island. Out of sight, out of mind.

Current and last stretch of Riviere St. Pierre cutting through the Meadowbrook Golf Course in Montreal Ouest.

Presently, only the 200 meters of river mentioned in the beginning of this entry remain visible. It makes a brief appearance in Montreal Ouest within the grounds of the Meadowbrook Golf Club. The water of the river (really more of a rivulet at this point) first sees daylight at the end of a four foot concrete pipe and by the time it reaches the edge of a Canadian Pacific Railway yard, it heads underground again. It was CPR that first owned this land and who later used it to establish a recreation club for its employees.

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It’s safe to assume that this one particular section of Rivière Saint-Pierre was spared only for the natural charm it helped give the golf course. Besides, what would Meadowbrook be without a brook? A bit west of this, on the same property, a trickle of water is all that remains of a former tributary. It barely registers as anything today, but the shape of its outer banks suggests a time when there was once something more substantial flowing through here.

The Meadowbrook Golf Club has been in the news recently. The present owner of the land wishes to sell a portion of it to developers who are eager to put up subdivisions. Not surprisingly, this has been fought tooth and nail on behalf of locals who see the golf course as a vital piece of green space for their neighbourhood. Three and a half centuries after Champlain first ordered the land surrounding the mouth of Rivière Saint-Pierre be “cleared off” and to be made “ready for building,” we arrive at the upstream end of this same river to find (not surprisingly), similar demands are still being made today.

The twin limestone channels through which the river makes its entrance into the sewer system.

So it’s from this point where we’ll follow the river underground; through the limestone infall found below the railway tracks. It doesn’t look like much, but it soon gets interesting once inside.

Picking up from the last entry, getting beyond the relatively small (yet steep and intimidating) slide of Double Ducker ended up requiring the use of some rope. It’s common for cities to add features like ladders, handrails or even stairs to allow workers to get up and down sloped sections like this, but I’ve yet to see anything like that here in Montreal.

So this time with nel58 and controleman along for the ride, we hammered a
steel piton into the gap where two sections of concrete pipe met, attached a knotted rope and made our way down. Easy peasy, quick and easy.

Controleman making use of the rope. The picture makes the drop look a lot smaller than it actually is. (Photo by nel58)

After the three of us reached the bottom, we headed down around the bend through the four foot pipe. A few minutes later, we arrived at what we had expected this would lead to: the Cote St-Luc Collector (CSLC) sewer. Here, the flow of Double Ducker enters a junction chamber from the right-hand side. A larger conduit, the main section of the CSLC, sits on the left side, perched on top of a slide. The contents of the two sewers flow smoothly over the sloped floor of the chamber eventually emptying into a single ten foot high pipe.

The junction where Double Ducker (on right) flows into the Cote St-Luc collector.

Worth noting here is how you can see this same junction in the river on older maps where a smaller creek veers off towards the West. The sewer system has effectively reversed their roles, though. Now it’s this smaller arm that carries the majority of the river’s flow.

Like its official name implies, the CSLC carries the waste from the predominantly residential community of Cote St-Luc as well as the more industrial areas found towards the lower reaches in Lachine. By Montreal’s standards its a medium-sized sewer, no more than ten feet in height.  It consists mainly of a horseshoe-shaped concrete pipe, perhaps put in place during the early 1960s to accommodate the increasing number of subdivisions being built at the time.

Not wanting to bother with yet another slide, we decided to take the easy route and head downstream first.  After tip-toeing carefully down the sloped floor of the chamber, we began sloshing our way through the concrete pipe that lay before us.

A few minutes later we arrived at an impressive junction chamber which picks up the flow from two other pipes leading into it. One sitting at higher elevations gracefully spills over a ledge into the CSLC creating a tranquil waterfall. It kind of gives the chamber a bit of a Tiki lounge. Les Baxter’s music and drinks served in coconuts would fit in well here. Whenever I think of this section, I can’t help but think of the word Shangri-la.

Looking upstream from a portion of the Shangri-la chamber.

Heading further downstream, it started to become clear that we’d be walking through relatively featureless concrete pipe for quite some time before seeing anything out of the ordinary. We decided to turn around, head back upstream to junction we came in through, and try to get up the slide on the left hand side.

Fortunately, this wasn’t going to require any rope to get up. Its edges were relatively dry and we were able to make it to the top and into the next section of concrete pipe.

Of course, a few hundred feet or so beyond this point, we encountered a much more formidable obstacle, and while it might not look like much in the photo below, it’s one of the more intense slides I’ve ever seen. It’s steep and unlike the other two slides encountered in this system, the water comes down violently, barreling down  through two sections of RCB; a good sign that the sewer was sitting directly below a set of train tracks. If this was in Toronto then there would have been a nice railing or something to hold onto, but like I said,  Montreal tends to lack such underground conveniences.

Looking up into the super steep slide. Note: it's actually far worse than it looks here. (Photo by nel58)

I stood at the bottom about twenty feet behind Controleman, who perhaps not realizing what he was about to get himself into, started climbing upwards. For a moment or two it actually looked as though we’d all be able to make it to the top of this thing. He made it about a third of the way up, but when he ventured from the dry shoulder of the slide and into the water, that’s when he lost control. He started sliding downwards a little, which would have been fine had his one foot not slipped out from underneath of him. Poor Controleman took a bit of a fall, then managed to get back up, at which point he started sliding again, straight towards me. Being a fair bit heavier than myself, I thought he was going to end up knocking me clear off my feet, but I was able to catch hold of him before the situation became any worse.

So now with Controleman thoroughly soaked (and maybe a little bit shaken up too), we decided it would probably be a good time to start heading back out. If we wanted to get past this particular section, it was going to require finding another way past it, perhaps through a manhole further upstream. We gathered up our stuff, climbed back up our rope and made our way towards the infall we entered.

Lessons learned: don’t step out into the middle of a slide, and when in doubt use a rope.

Finally, here’s a very aproximate path of both the Cote St-Luc collector (shown here in red) and the stretch of Double Ducker that leads into it. You can zoom out in order to see the full extent of the system.

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Don’t worry, we’ll get through this thing eventually.

From a distance, the drain (which I’ve named Double Ducker) beginning at the edge of the Meadowbrook Country Club doesn’t really appear to be much. In fact, if it wasn’t for the old limestone construction of its inlet, then I wouldn’t have bothered looking at it more carefully in the first place. The two entry points are all of two feet high. Rarely does that sort of size suggest anything good lies beyond.

It wasn’t until I got closer that I realized that the two channels are actually double this height. Over the years, sediment and other debris has more or less created a dam of sorts, but beyond this it soon dips down and opens up to reveal the full height.

Four feet isn’t all that comfortable a height to walk through, but it’s better than two feet. So I slipped on my chest waders, squeezed through the left side and crouched through 75 feet or so of what appeared to be hastily cut limestone blocks.

I was now passing underneath the original mainline of the Canadian Pacific Railway built in 1886. It smelled less like a man made drain and more like an old cave.

Looking back through to the entrance inside one of the limestone channels.

When CPR built a rail yard parallel to the main set of tracks in the late 1940s, more of the river required covering.

Detail of 1952 map showing Riviere St. Pierre (and its tributaries) passing under CPR's rail yards.

By this time the construction material of choice wasn’t limestone, but concrete. So at this point, the two channels come to an end and a rather ruddy–looking concrete section in the shape of an arch begins; its floor looking as though it had been quickly slathered in place. At this point I could finally stand up. The smell of sanitary flow wafting in from up ahead gave a good indication as to where all this was heading.

At the end of the limestone section with a drillhole in the ceiling bringing in a touch of natural light.

A few feet further and the concrete arch suddenly increases in size with enough room to stand up in and then some.

Looking a little forlorn while standing inside the largest concrete arch section. (Note the imprints left from the wooden forms used during construction.)

Only to become slightly smaller again thirty feet later.

Looking through to the smaller stretch.

And then things get really small with the start of a section built using RCP less than four feet high. None of this really makes sense. Much like actual rivers, sewers have a tendency to get larger as you head downstream in order to accommodate the increasing amounts of water picked up along the way. This small > large > larger > small > smaller sequence is still a bit confusing.

Looking ahead (but not forward) to the upcoming stretch of small RCP.

So at this point, I had effectively crossed the width of the entire railway yard above me. The more refined looking section of pre-fabricated RCP that lay ahead was obviously added more recently. 1973 is the last map I have that shows the river flowing past this point. It was around this time when the city began to implement a more comprehensive wastewater management plan. This stretch was most buried as a part of that effort.

Shining my spotlight down the small pipe, I saw no end in sight, but could hear the rumble of water suggesting bigger (perhaps more interesting) things lay ahead.

I decided to keep going. Here, the concrete is smooth, almost polished. Combined with a fine layer of sanitary “scum” on its bottom and the slight downward slope, it was slippery enough for me to lose my footing a couple of times. After crouching through about 250 feet of this pipe, I eventually reached the source of the rumbling: a seven foot high slide.

Normally getting past something like this would be kid’s play. Even when civil engineers don’t thoughtfully add ladders or step-irons, you can often make your way down safely enough by keeping to the dryer edges. But here there’s no ladder, and given the slipperiness of things, I came to the conclusion that even if I could get down safely (and dryly), I might not be able to get back up so easily.

So I did what any prudent drainer would do: I decided to wait and come back another day, with a couple of friends, a bit of climbing gear and a length of rope.

Coming up in our next episode: Double Ducker meets Ovalflow. Stay tuned.

Standing below a bit of natural light pouring in from above a manhole shaft.

Judging by the pre-fabricated sections of reinforced concrete pipe, it looks as though this portion was constructed a bit more recently. Sometime around the 1970s, perfectly round RCP seemed to have become the standard material for sewers and storm drains in Montreal. It can make for somewhat dull underground experiences, especially when long stretches of the stuff are involved. Fortunately, this particular sewer ended up having a nice combination of other features to help break the monotony.

The visibility was fairly poor, which we’d later discover was the result of cold air blasting in through a little 6″ pipe. During the autumn and winter months, the air inside sewers stays a few degrees warmer relative to aboveground temperatures. When outside air finds a way in, it can can lead to somewhat unfavorable exploring conditions. In this case, a dense “fog” had filled the sewer. The lights of our headlamps only penetrated a few feet in front of us. Regardless, we began making our way northwards underneath Cote-St-Luc.

Sloshing our way through the shin-deep water, we eventually arrived at a nice wide junction chamber. Nothing too fancy or out of the ordinary, but at least at this point the fog had subsided enough to make it a bit more practical to be able to take a photograph or two.

nel58 and myself lighting things up.

We chose to follow the smaller pipe to the right out of which we could hear the rumbling of water; a sign that something a bit more interesting lay ahead.

Fifty feet or so in, we found ourselves inside a  rusted corrugated metal pipe. I have no idea why the change occurs, but it’s there. Maybe it’s a culvert that existed beneath a roadway before the rest of the sewer was put in place. As the picture below can attest it was a bit on the dirty side. I’m always having problems convincing people that sewers aren’t as bad as they might imagine them to be. I’ll admit that a photo like the one below does little to support my claims. Fortunately, these places never smell as bad as they look. Honest.

Being careful not to get a dangling condom, piece of toilet paper or god-knows-what-else in the face, we pressed forward.

We eventually reached a lovely little chamber responsible for the noises we had started hearing from the previous junction.

Accidental modernism found forty feet below.

Sometimes it’s the little stuff that helps make things more interesting. In this case, a curtain of water falling over a diagonal ledge or reinforced concrete beams. As much as traveling through pipes is a part of  underground exploration (which I’ll admit can sometimes get boring), it’s this sort of stuff that we look forward to discovering the most.

Since neither of the two pipes ahead of us were tall enough to stand up in and would likely only get smaller, we decided to head back.

After returning to the first junction, we started heading up the pipe that ran off to the left. It didn’t take long before we realized it would probably be some time before we came across anything other than RCP.  A basic system map from the 1960s  shows the main arm of the sewer continuing on to the northern boundary of Cote-St-Luc. Reaching that point would involve walking against the current for a good 3 kms from where we were standing. Not feeling up to that particular task, heading back downstream from our entry-point seemed like the more appealing option.

Roughly fifteen minutes later, this is what we arrived at this strange little room:

Odd engineering found at the end of the line.

Two relatively dry CMPs veer off to the left and the rest of the wastewater flows through the four foot high square section seen on the right. Shining my spotlight up through this part revealed no end in sight. I figured it was most likely going to be like this for the entire width of the railway yard sitting directly above us. Regardless, I started to crouch down through it.  Soon afterwards, I found that the bottom of the floor dropped off abruptly to the point where I was now up to my waist in water. Realizing my backpack (and more) would probably get soaked if things got much deeper, we decided it would be best to turn around and call it a day.

Next up: Downstream towards Lachine.

Inside the Rockfield combined sewer overflow conduit

Picking up from where we last left off, this stretch takes us through the inside of the Cote-St-Luc collector sewer at the northern edge of Lachine. From here it snakes its way southwards towards the Lachine canal, never straying too far from the original course of Riviere St. Pierre. Approximate round-travel distance: 4 kilometers.

I never look forward to having to cover larger distances inside sewers here in Montreal. The depth will vary, but 2-3 feet tends to be the norm. That might not seem like a lot, but when you factor in the speed at which it’s flowing and the amount of gear these types of trips can entail, it doesn’t take long before it starts to feel like a solid cardiovascular workout. This is especially true when you’re walking against the flow.

Here’s a general overview showing the CSL collector (the dark red line), the estimated path of Riviere St. Pierre and a few of the features described below.

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For the first kilometer and a half, this portion of CSL collector is pretty straightforward: 8×10 feet in diameter with a shape that’s typical of concrete sewers built in Montreal between the 1920s and 1970s. A smooth horseshoe-shaped arch covers a course aggregate floor that that slopes towards the edges. During dry weather, the edges of these types of sewers are usually dry. City plans define this section the “sidewalk”; but that term’s a bit misleading. Due to the angle, it’s actually terrible to have to walk on.

Typical Montreal-style sewer with 'sidewalk'

Because of the broader arc of the sewer and for some of the features described below, I decided to name this length of the CSL Collector “Ovalflow.”

It’s unclear when the sewer replaced this portion of Riviere St. Pierre. While bits and pieces seem to have been covered as early as the 1930s, I suspect everything was eventually reconstructed during the mid-1960s when the entire area’s sewers were integrated into a much broader system.

By the time the sewer reaches the area of Lachine known as Rockfield, things start to get a bit more interesting.

Rockfield regulator chamber.

At this point the CSL collector officially comes to an end inside a rather unusual chamber containing a number of interesting features. As seen in the photo above, on one side of the channel are four cells. All the water flows into the cell closest to the camera at which point it falls down a sinkhole into an even larger sewer- the appropriately named St-Pierre Collector, which we’ll get to in future entries.

Detail of city planning map showing chamber and connecting sewers.

The other three cells contain a metal cylindrical object suspended directly above a three-foot wide hole, one of which is entirely blocked up with sludge. Above these are a number of counterweights and a mechanism (shown here) likely designed to lower each cylinder so that it covers the hole. Since each hole seems to lead to the same sewer further below, I’m not sure what purpose these things actually serve. A water monitoring device (or flowmeter) sits high in one corner of the chamber, but it’s unknown if it has any connection to the large plugs or if it simply sends an alert whenever water levels start to rise.

One of the three 'plugs' positioned above a sinkhole.

Also found in this chamber is the beginning of a rectangular shaped conduit situated roughly eight feet above the main channel of the sewer. The principle here is simple: when the water inside the sewer reaches a certain height, the surplus flow is diverted through this tunnel and out into the open water- in this case, the Lachine Canal.

Entrance point of the Rockfield overflow.

This is one of the drawbacks of a combined sewer system. Most of the time everything gets sent off to the treatment plant as intended, but during heavy rainstorms, the system can become overburdened to the point where sewage spills out into the open water. Fortunately, these events only seem to happen a few times a year, but they’re still a source of significant water contamination. If you’ve been warned not to swim in the Lachine Canal (or elsewhere on the island), combined sewer overflow events are likely the reason why.

Midway point inside the overflow conduit approaching the Lachine Canal.

This eleven by five foot high conduit (known as the Rockfield Overflow) runs for a quarter of a kilometer, but because the outfall at the canal is submerged, one can only travel about two thirds that distance. Any further and you’re soon up to your chest in canal water.

At this point your only choice is to turn around.

Next up: Eastbound Traffic.

How else dispose of an immortal force
No longer needed? Staunch it at its source
With cinder loads dumped down? The brook was thrown
Deep in a sewer dungeon under stone
In fetid darkness still to live and run –
And all for nothing it had ever done
Except forget to go in fear perhaps.
No one would know except for ancient maps
That such a brook ran water. But I wonder
If from its being kept forever under,
The thoughts may not have risen that so keep
This new-built city from both work and sleep.

- excerpt from A Brook in the City by Robert Frost, 1923

I’ve already written a bit about how most of Riviere St. Pierre has been lost, but it’s definitely not the only river or creek to have suffered this fate. Perhaps “lost” isn’t the best word to use. While the majority have been removed from both the landscape and our collective memory,  their waters can still be found beneath us, flowing through the island’s sewer system.

The relationship between sewers and streams is one that I’ll be returning to often. While the the two may not always follow the exact paths, there are often direct links between where a creek once flowed and where a sewer exists today.

1953 photo showing construction of the 14 foot high Meilleur Atlantique collector sewer in the north-island community of Bordeaux. The creek once known as Ruisseau Provost can be seen to the right. (Photo source: City of Montreal Archives)

By looking at early maps of the island like the ones drafted before the mid 1800s, we can get a better sense of just how many watercourses used to flow over the landscape. Using a series of older maps and one provided by the city’s water monitoring group, I put together the following map to give an approximated view of the island’s past and present surface hydrology:

Unlike a city such as Toronto, where traces of former creeks and rivers are often quite obvious, signs of Montreal’s lost watercourses are a bit harder to come by and require a bit more digging.

Take for example all the things that used to flow in and around central Montreal:

Approximated paths of creeks in Montreal prior to 1800.

The most we can hope to see of this former network is in a quiet corner of Outremont, where small sections of the creek once known as Ruisseau Springrove appear. Discounting the street in the area named rue Springrove, one could presumably find further evidence of this little stream on the way up Mount Royal. Everything else shown in the map above has been erased from the landscape entirely. Even the twin ponds of Parc Lafontaine whose curves take the approximate shape of the creek that once passed through Logan’s Farm are concrete-lined fabrications. When necessary, their contents drain into the sewer that runs beneath the southern portion of the property.

Generally speaking, one would have to drive a half hour or more away from the centre of downtown, out to Dorval, Ville St. Laurent or the East island before they came across a bona fide creek. Even then, many of these have been partially covered or have had their tributaries amputated. The few sections that do remain visible are often found within either golf courses or areas designated as parkland. They also tend to exist in the small portion of the island that doesn’t make use of a combined sewer system. Not surprisingly, many are also highly polluted.

Charting the evolution of the island’s creeks can often be a daunting task. Older maps from the early 1800s show only approximate paths with many minor creeks apparently deemed unworthy of inclusion. By the time more detailed maps started to emerge around 1820, we see that many of these watercourses had already started to disappear.

Detail of map illustrating the extent to which creeks had started to disappear by 1853.

By the 1870s,  little of the original network of streams in the city could be found, having been used to help provide a steady flow of water through the city’s developing sewer system.

Fortunately many of the areas found outside the city, can be traced relatively well. In particular, the creeks Molson, Raimbault, Provost and portions of St-Pierre can all be seen in a fair amount of detail on maps maps from the 1900s, right up until the early to mid-1950s before they too were driven into the sewer system.

The far-reaching arms of Ruisseau Provost (or Cote Des Neiges) shown here on a map from 1916.

Whereas maps are able to show us part of the picture, books tend to reveal less about most of these creeks. Photographs are uncommon and names are often only mentioned in passing without any further details regarding their size, their flora and fauna, and the role  they might have served for those who lived near them.

1950 photo of Raimbault creek which once passed through the burrough of Cartierville. Photo source: Ville St. Laurent Archives.

Confusing matters further are the multiple names ascribed to individual creeks. Ruisseau Provost and Ruisseau Cote-des-neiges were both used for the system that once flowed from the edge of Mont Royal all the way down to the north shore of the island. The English might have had a different name for it altogether. Today the creek’s waters flow through one of  the island’s largest collector sewers: the Meilleur-Atlantique, a title which refers only to the main streets it passes under. I don’t imagine it will ever be called anything else, although underground explorers such as myself might someday give it a goofy-sounding name for their own amusement.

So hopefully this gives people some idea of what used to be found on the island. We’ll look at some of these sytems in a bit more detail eventually, but I figured it would be of benefit for some to give  a general overview out of the way first.