Norman Kittson was a famous fur trader in the early history of Minnesota. He built a huge mansion on the site where the St. Paul Cathedral now stands. After retiring from business, he built horse stables in the Midway area of St. Paul, and in Erdenheim, Pennsylvania. The St. Paul stables were known as Kittsondale.
Midway, as a place name, made its appearance at least as early as 1885, when “Midway Heights” was platted—midway between Minneapolis and St. Paul, of course. The same symmetry came into play when the sewer drainage of the area was laid out. Although there had been small diameter sewers in the area for years it was not until the late 1920s and early 1930s that the large-bore “Kittsondale tunnels” as they are called in Public Works documents, were built. Basically, two mirror-image tunnels, draining sewage in opposite directions, were dug. Kittsondale East drained sewage from Midway toward the east, with an outfall on the Mississippi at Bay Street, while Kittsondale West drained to the west, with an outfall in the shadow of the Lake Street Bridge.
It became a question with me right away whether the two tunnels connected somewhere under the Midway, providing a continuous pathway, such that an intrepid sewer explorer might walk clear under the city and emerge at the opposite side. This turned out to be a mere “pipe-dream,” however, as the tunnels diminish in diameter upstream, and nowhere connect.
The Kittsondale tunnels are distinguished from all other tunnels under the Twin Cities by their curious architecture. They contain vast subterranean stairways along their course, stairways that descend more than a hundred feet into the earth. And strangely enough, these stairways were not intended for human beings. What, then, was their purpose?
Stairways, or “flight sewers,” as engineers call them, are occasionally used where a sharp drop is necessary. Ordinary shafts can also serve this function but are plagued with problems of waterfall erosion at the bottom. The Kittsondale stairways served to convey large volumes of water from the highlands of St. Paul down to the level of the Mississippi. Nowadays, an “impact dissipater”—looking sort of like a hunk of steel Swiss Cheese, complete with holes—would be built at the bottom of a shaft, if such a situation arose. But in recent years there has been a trend towards using a simple steel plate laid flat on the bottom of the shaft to absorb the falling water’s impact.
While flight sewers are not uncommon, even in the Twin Cities, what makes the Kittsondales so special is that they contain spiral stairways. Now, while I had long known of these famous spirals, it had not immediately occurred to me that one of them was located directly under the former surface course of Cascade Creek. In other words, the elusive creek, or the water from its watershed, was now draining to the East Kittsondale tunnel. A spiral stairway—a man-made cascade of sorts—had replaced the old, natural waterfall at the river bluffs. The diverted Cascade Creek now joins the Mississippi three-quarters of a mile upstream from Ross Island, where I had originally looked, based on the old maps.
But for a little more about these remarkable subterranean spirals. Blueprints of the Ayd Mill spiral suggest a subterranean Tower of Pisa. The spiral has vertical dimensions of more than a hundred feet and is 20 feet in diameter. The stairway was “cast in monolith” (as a single mass of concrete) in 1929. Together with the outfall tunnel to the river it cost more than half a million dollars. The spiral consists of seven whorls of stairs wrapping around a hollow core. There are 24 steps to one turn of the spiral, and I always got dizzy going up or down the spiral, even at a normal walking pace. The spiral is now more than three-quarters of a century old—time enough for the growth of mineral formations mimicking those found in natural limestone caves. The stairs, accordingly, were coated with a thick, orange flowstone, the lime minerals having been dissolved from the upstream concrete and redeposited here.
The hollow core of the spiral is topped with a spiderweb-pattern manhole lid, which proved useful to me. When going on long trips through the Kittsondale system, I always used to stop here to check whether I could see a reassuring ray of sunlight streaming through the grate at the top, far above, and hopefully not storm clouds.
Following the tunnel upstream beyond the spiral there was a 3-mile hike ahead. Some parts of this tunnel were heavy with solvent vapors at times, enough that you would fear lighting a match. Eventually, where the tunnel passed under Interstate 94, near Concordia College, I crawled through the “whale’s ribs” like another Jonah, and up the manhole. The “ribs” were all that remained of a previous tunnel structure that had entirely rotted away in the warm sewer gas, leaving only the skeleton. Once during one of these “door-to-door” trips I entered while the sun was shining and exited in a blizzard that had sprung up meantime.
The West Kittsondale tunnel, built in 1931, on the opposite side of St. Paul, is not associated with any known historical stream. Nor, for whatever reason, does it have thick mineral deposits. To compensate, however, it has three spiral stairways. While its main spiral, located under the intersection of University and Fairview avenues, resembles the Ayd Mill spiral, the other two are small-diameter redbrick spirals situated at points where branches join the tunnel. An interesting difference between the small and large diameter spirals is that they coil in opposite directions. It became a point of humorous contention as to which type of spiral followed the supposed toilet-flush direction for the Northern Hemisphere.
The unique West Kittsondale tunnel was a favorite of one of the Twin Cities’ first subterranean artists, the photographer David Gericke, who was profiled in the Minneapolis Star & Tribune in 1987, thus becoming a predecessor of the better-known Julia Solis in New York City.
Because of its three spirals, I gave West Kittsondale the name “Triple Helix Tunnel,” which was adopted by the on-line sewering community. I was thereafter contacted by Jason Chapman, creator of the popular Australian website which had an astronomical number of hits. He was planning another one of his “World Tours” and wanted to visit the Twin Cities based on what he had read of us on local websites. Although I had been contacted by other Aussies in the past, this was the first guy to actually follow through.
After exploring the Kittsondale side-spirals, we walked to the very end of the main tunnel, more than one mile in, passing a couple of powerful “fire hose” springs jetting from the walls. Arriving at the main spiral, we walked upwards. At the top, we continued on for some distance in the ever-diminishing pipe, to a place where we could peep out at the Snelling Avenue street scene, a sort of sewer voyeurism. Here, as elsewhere, it was useful to have a “periscope,” which for the gear-minimalist was a dental mirror, carried for protection in a plastic toothbrush case. The dental mirror, pushed up through the ventilation holes on a manhole lid, and slowly rotated, offered a 360-degree view of the surface above.
On the way out, as we approached the river again from whence we had set out, we encountered the familiar Kittsondale tunnel phantom, a mist of water from a shaft in the ceiling, which from a distance resembles a human being walking towards you, because of its constantly changing form.
Excerpted from SUBTERRANEAN TWIN CITIES.