DrainsofmyCity
Mission: Northberm's Throat
May, 2005
It was a warm, clear day as I went south in the city with my boots, camera, and other equipment weighing down my backpack. Hoping to find a nice place to hide from the sun and have a little adventure, I began to scout around for a potential entrance to my target.
My drain of choice for the day was somewhat elusive. I knew roughly where it was, thanks to a proliferation of manholes, but the problem was finding a suitable entrance. There were no outfalls, and popping a manhole next to a busy roadway is never one of my preferred options. My search slowly lead me away from the easy entrances, and I was forced to begin popping manholes at random in a residential neighbourhood.
After several unsuccessful tries, I finally hit pay dirt. Although out in the open, there seemed to be no one around to observe my activity. I geared up quickly, and lifted the manhole. The dark space underneath exhaled the cool, reassuring smell of storm sewer, and I lowered myself inside. I leaned back on the concrete shaft, and quickly dragged the manhole lid back into its collar overhead. It slid shut with a firm clang that reverberated into the dark space below me.
Suddenly at odds with the darkeness, I dug through my pockets for a flashlight. My favourite LED light was quick to be found, the reassuring blue beam providing faint illumination as I descended the ladder rungs. Stepping into the stream of dirty water in the pipe, I shone my light first upstream, then down. The tiny light was too faint to be of real use, so I put it into a pocket and put on my headlamp instead.
Unsure exactly what this new drain had in store, I decided to head upstream first. The line was 1350 RCP, with slick, wet walls that stretched straight ahead. I crouched along for a few minutes, but the pipe's bottom soon began to fill with a large amount of sediment. I was unwilling to trudge through a sand-filled backbreaker when there were probably better things downstream, so I turned around.
I went back to the manhole shaft where I'd entered, and after a quick standing break, kept going downstream. It was still 1350- a nice backbreaker size, and there was only a little bit of sand to bog down my footsteps. I kept a fast pace, bent over like some strange underground speed skater. The manhole rooms were evenly spaced, allowing me to stand and rest my back every few minutes. The pipe was actually pretty boring- the only thing I remember is that it eventually curved to the right, and then to the left.
I'd been crouched over for about ten minutes when the 1350 finally dumped me into a larger pipe. Another 1350 RCP opened on the right, but I was definitely more interested in the 1950 that kept going straight ahead. I was really warm after the fast crouching walk, and took a minute to strip off my sweater before heading off.
The 1950 was also RCP, and it was very humid. Water vapour hung in the air, and droplets ran down the walls and hung from the ceiling. After spending any amount of time in a backbreaker, I always appreciate being able to walk upright again- and being able to move faster. Curving to the left, the pipe surprised me by emptying into a large junction. The flat floor ahead sloped down into an unexpected 2400 oval, and another 1950 RCP dumped in from the left. Ladder rungs went up one wall, into a shaft covered by a grated manhole that let in faint sunlight. I noticed layers of small, floatable debris stuck to the walls near the ceiling (high water mark)- indicating that this junction had been filled to the top with water during a past storm. I'm constantly amazed at the force of waters that occasionally surge through storm sewers, and mindful of how dangerous these places could become. Although the 1950 on the left looked tempting, it couldn't compete with the attraction of the 2400; and I kept going downstream.
The air was still fairly humid, although there seemed to be a faint breeze. The pipe was straight as an arrow, the concrete segments fading into the distance. I passed four or five manhole shafts; bright square openings high up on the walls that sprayed falling water droplets into the drain. The bottom of the pipe was mostly clear, smooth-flowing water, although some areas had accumulated nearly a foot of sand.
I walked for twenty minutes, and just when I was starting to wonder if there was anything exciting up ahead, the shape changed. I entered a pipe with one sharply slanted wall, and one curved- as though it was a normal RCP with a wall dividing it into uneven portions. Known as double-barreled pipe, it carries both storm and sanitary sewage- divided by a wall. One of the rarer shapes in Edmonton's sewer network, it was interesting to see once again. Unwelcome was the smell- a strong reek hung in the humid air, causing me to pause and seriously consider the air quality. I've often had doubts about the joint seals in double-barrel pipes, and the smell here didn't offer any reassurance. Also slightly disturbing were the dark-colored stains seeping from the gaps where the pipe sections were joined.
My curiosity was irrepressible, so despite slight misgivings I kept going. The faint roar of a waterfall ahead began to reach my ears; and I could feel a draft moving the air past me. A couple minutes of walking brought me within sight of the end of the line- but also to one of the most interesting dropshafts I've seen in this city.
A rust-coated chain hung, blocking my path. To my right, rusty ladder rungs (one of which was snapped off) went up a shaft to a manhole far above. A strange assembly of rusty metal bars ran out to a section of ladder that descended into the shaft. The large dropshaft, 2.4m across, gaped open three feet beyond the safety chain. Ducking under the chain, I leaned over the edge to see how far down the hole went. About two stories below in misty darkness, the drain water splattered onto hard concrete and ran off into another pipe. My light was too faint to get a proper idea of the situation, so I backed off the lip, retreating behind the safety chain.
The bar/ladder construct above the dropshaft was clearly meant to allow access to the pipe below, leaving me with a dilemma. I really wanted to climb out and down, to explore the lower reaches of the drain; but the ladders were coated with rust and looked a little unsafe. I spent a few minutes standing in the dark, at the lip of the shaft, considering my options. The temptation was difficult to resist, but after reflecting that I was alone, and no one even knew where I was, I decided the risk was not worth taking. After a final, longing glimpse down into the darkness, I backed off and settled for just taking some photos.
Left with no other option, I turned around and went back up the drain. I passed through the 2400 oval back to the junction, and went back into the 1950 looking for a suitable exit. I managed to make a quick, although highly visible escape back into the sunlight; a brief struggle to re-seat the manhole lid properly was the only thing that slowed me down. A couple out for a walk gave me strange looks as I passed by; soaked from the knees down, wearing a headlamp and rubber boots, I gave them a big smile and kept going.
The large junction, as seen from the 1950 RCP. 2400 oval dead ahead, the second 1950 on the left.
Breathy 2400 oval throat.
The oval joins the double barrel pipe. One of the square catchbasin "windows" can be seen on the left wall, gushing water.
Inside the double barrel pipe- quite big, now that I look at it. Sanitary sewage flows, separated from storm, in the smaller portion of the pipe behind the slanted wall.
End of the line at the dropshaft. It's hard to see, but trust me- it's just beyond that safety chain. There's a neat structure consisting of some bars and a ladder reaching out over the shaft, on the right wall; as well as some manhole rungs leading up another shaft to the surface.