West Bank Tailraces (Mill Ruins Park).
Minneapolis and the former city of St. Anthony both grew around the industrial power of St. Anthony Falls. Beginning in the mid-1800s, mills based on water power processed a wide range of raw materials, including lumber, grain, and wool. Power for these mills was based on the effects of water and gravity, water being brought in at the river level above the falls, dropped through shafts to spin turbines, and then discharged into the river below the falls. On both sides of the river, inlet canals were constructed from above the falls along the bluffs above the lower level, which were lined with mills. Pipes led to each mill, and tailrace tunnels carried the outflow from under each mill back out to the river. Today these tailrace tunnels are some of the only remnants of the industrial might of Minneapolis, most mills being reduced to ruins. The inlet canals have been filled, although part of the St. Anthony Main Street canal on the East Bank once served as a sewer tunnel and may still exist.
At the current time, most of the East Bank tailraces are inaccesible, I plan to update this page if and when I explore that side of the river. The West Bank tailraces have been excavated and turned into a city park, which allows the public to see many of the remaining mill foundations and tunnel outfalls. Two main systems can sometimes be accessed, the largest composed of the First Street tunnel, City Tunnel, and their tributaries. There are also erosional caves, abandoned tailraces, sewer utility tunnels, and backfilled TCRT power tunnels connected to this system. At one time most of the tailraces were likely connected underground, via shared utility and sewer tunnels, but many of these have bee bricked up or destroyed.
The tailraces are very photogenic, being relatively large tunnels for
the Twin Cities region. All of these photos are in the first section of
the First Street Tunnel. Deeper sections of the tunnel are flooded with
up to 8 feet of mud and water, and a variety of boats and homemade rafts
are often found drifting around inside. By boating farther back into the
tunnels, one can find a number of 100-year old natural erosional caves,
including the City Waterworks Cave (currently unconnected to the City Tunnel).
The City Tunnel was originaly the tailrace from the municipal waterworks,
and is the northernmost existing tunnel on the West bank. It is still used
in summer months as a tourist display, with water dropped in from the mouth
of the former inlet canal, and released from the City Tunnel outfall to
make the park look pretty. Currently this tunnel is being upgraded so that
waterflow will not damage the sandstone and limestone walls.
These photos show the sewer utility tunnel and TCRT tunnel connected
to the Standard Mill tunnel. The TCRT tunnel carried power lines for the
streetcar system from the company power plant (now UMN's steam plant),
across the Stone Arch rail bridge, up through the old Standard Mill tailrace,
and through a sandstone tunnel under downtown. Both the old Standard tunnel
and TCRT tunnel have been backfilled, and the utility tunnel connection
to the city sewers nearby has been bricked off.
A headrace pipe from the canal through an abandoned mill basement,
and the newly lighted Excelsior Mill tunnel. More
exploration of this tunnel can be seen here.
Two maps showing the mill tailrace systems. The first shows the headrace
canal (shaded grey), and some of the tunnels. The 2nd shows the combined
First Street tunnel and City Tunnel systems. The small tunnels at the lower
right are the abandoned old Standard Mill tunnel, sewer utility tunnel,
and TCRT tunnels.