Bridgeport Lock and Pump Station, 1880s

The Illinois and Michigan canal was deepened, being completed in 1871, in an effort to clean out the rivers by reversing the current and flushing the river with lake water. The city had paid the bill for this but was reimbursed by the state after the Chicago Fire of October 1871. This was the first attempt to reverse the flow of the Chicago river and was partially successful. The original Bridgeport lock (east of present Ashland avenue) was therefore removed. In time, though, huge increases in sewerage discharges, silting, and changes in lake conditions negated the accomplishment. Meanwhile the untreated sewage flowing downstream raised the consternation of downstate citizens. The state legislature became involved in 1881 and directed that the city take several measures, including the reinstallation of the Bridgeport lock and pumping station. The new lock and pump station were located to the west of Ashland avenue.

During the dry season water was pumped out of the South Fork into a supply channel (the southern leg above), while the "backward" lock of the main channel kept the water from flowing back into the river. During high water season or during heavy rain, the lock was simply thrown open and the water flowed by its own weight. This engineering scheme was outmoded by the opening of the Sanitary (or Drainage) canal in 1900. The Bridgeport pump was soon shut down after a law suit (based on a clause of the Constitution of 1870) which prevented the state from subsidizing the operation of any aspect of the canal's operation.

Source: A. T. Andreas, History of Chicago, vol. III (Chicago: A. T. Andreas, 1886), p. 136.


See the Illinois Department of Natural Resources I & M National Heritage Corridor home page for a picture of the original Bridgeport lock site (Note: long-load page).

See also this section on typical lock workings of the 1830s. (Though the I & M did not open until 1848, its locks were based upon the same technology.)

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