SEWER SYSTEM OF MINNEAPOLIS.
MINNEAPOLIS, MINN., has a system of sewers, some of which,. as will be seen from the accompanying illustrations are capable of being navigated by a good-sized scow. The North Minneapolis sewer tunnel, herewith illustrated, starts on Fifth street North, near Bassett’s creek; and, taking a diagonal course under the city and under all other sewers, discharges its contents at the foot of Eighth avenue South. This tunnel is seven and one-half feet wide, the same in height, and along the bottom there flow constantly from ten to twelve inches of water, or more than enough to carry a good-sized boat. Some times this tunnel contains three or four feet of water, in which case the current is dangerously swift and strong. A cross section of this tunnel is shaped like a horseshoe. The walls up to the spring of the arch are of limestone; the arch itself of concrete; and the bottom orbed of paving stone. It is the largest and deepest sewer in the city, being at about Hennepin or Nicollet avenues fully forty feet beneath the surface. It is also the most important sewer in the city, for not only does it drain all of North Minneapolis, but likewise the districts about Loring park and Lowry hill. When running full, it will discharge into the river the enormous quantity of 212 cubic feet of water per second.
In this connection it may be noticed that the honeycomb of sewers under Minneapolis, if extended in a single line, would reach a total of 138 miles, or almost to Duluth. On these sewers has been spent the sum of $4,145,528. Some of these sewers are of stone, others of brick, others of cement or of combinations of the three. Some of the smaller ones are of specially prepared vitrified pipe. In shape they are oval, eggshaped, or like a horseshoe.
In the illustrations given with this article will be seen a group of sewer laborers at the top of a manhole; the North Minneapolis sewer tunnel. The cascade stairs are under Third avenue North, the fall is on First avenue North near Fourth street, and the small cascade is the discharge from the courthouse sewer.