The CSO overflow drain begins as a roughly 20×200 ft. chamber mounted to the top of the vastly larger CSO (Combined Sewage Overflow) Tank. Should, for some extreme reason, the CSO tank become full, slotted grilles in the sides of the overflow drain will permit excess sewage to flow into the drain, and out into Cootes Paradise. Not pretty. Thankfully, this only happens in the worst of storms, and at that point the CSO is mostly full of stormwater anyway.
We began our journey by wading through a large culvert to the southbound side of the 403 highway. Just before the Main St. bridge, it passes underground, and after a time, a small opening became visible to us on the right hand side. It looked relatively clean and dry, so we headed over to check it out. After going through two or three different styles of pipe, including a very interesting metal-coated horseshoe shape, we came out into a large concrete chamber, with a substantial metal door to our right. To continue ahead, we’d need to climb up an approx. 15 ft. wall, and over a railing at its top. Thankfully, having read the Vanishing Point page about this drain previously, we came prepared with a length of rope.
It took nearly 15 minutes for us to successfully loop the end of the rope around the railing and to climb the wall, at which point we continued down the passage, going gradually up and to the right. Eventually, we came to a long room with small gaps along the tops of its walls, and a sheer wall with a ladder at its far side. Here we knew we had reached the end of our adventure, though I was determined to do some poking around and try and figure out how the Hamilton drainage system was designed to work.
Kowalski, in his second visit to the “Wall of Anguish”, took a photo of the inside of the overflow chute, to which he commented “A view inside one of the tanks does not say good things about their capacity.”
With no disrespect to Kowalski, I found this rather suspicious, as the photo he had taken (while it had a limited sense of scale) suggested to me a chamber too small to hold anything in the way of significant storm runoff. Upon seeing this chamber firsthand (the first two photos to the right were taken in it), I felt my suspicions to the confirmed. And so, with the assistance of a bit of rope I eased myself and my camera into one of the “overflow slots”, and encountered the true CSO tank, pictured here.
We dropped the rope into the tank, and measured its height at about 60 ft. From surveying the tank from ground level, our best estimate of its dimensions are about 300 by 200 ft. Quite a room.
Lacking the equipment to explore the tank proper, we began setting up the equipment for a brief photo shoot, before heading back the way we came, and exiting out of a manhole on Main St. across from the Spectator building.
Photography
The CSO overflow was one of the most enjoyable places I’ve shot undergound yet. Looking at other photos of the same area, it seems like we got quite lucky; there was minimal moisture, no running water, and very little deposited solids in any of the drains we passed through. This gave me plenty of opportunities to set up my tripod and place lights where I wanted them without having to worry about anything being washed away.
In the photos to the right, you’ll see my beginning to experiment with using light painting to trace the outlines of figures and passages. You’ll also see several long exposures that turned out quite well, as well as some very interesting calcium deposits that had formed from groundwater leaking into a manhole shaft.
Followup
The next day I had some time off and went down to the park above the CSO to try and get a better grasp of its dimensions. While there, we spent some time looking at the pump house and the surface equipment that was visible. Halfheartedly, I gave a tug on the access door and it sprung open. So I went down into the pump room to take a look, but an alarm started going off, so I left. Down there I saw several large pipes coming out of the floor, with significant valves on them, and also a hatch in the floor that seemed to lead to a lower level.
We went across the street to Timmie’s, and about half an hour later a city car pulled up at the pump house, a guy got out, looked around, got back in, and drove away. So much for locking doors.