May 13, 2025
Local News

Then & Now: Aux Sable Creek Aqueduct – Channahon

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The Then image shows a photograph of Aux Sable Creek looking south. The arched bridge in the foreground was built in 1871, and the Aux Sable aqueduct can be seen in the distance. (Photo courtesy)

A bit of ingenious engineering is required to construct aqueducts to cross streams, creeks and rivers along the Illinois and Michigan Canal route.

Along the 96-mile trek through the wilderness, the I&M Canal needed a series of 15 locks to navigate the 141-foot elevation change from Chicago to the Illinois River.

Aqueducts along the canal generally were composed of a trunk section, which carried the canal across an intersecting stream, supported by abutments at each end.

Canal engineers had to design and construct five aqueducts to carry the canal over other bodies of water, such as rivers and creeks. The five principal aqueducts, moving from east to west along the canal, were built over Aux Sable Creek, Nettle Creek, the Fox River, Pecumsaugan Creek and Little Vermilion River.

A sixth aqueduct also was constructed across the Des Plaines River and served a feeder canal running between the Kankakee River and the main canal. Serving as a source of water for the canal, this is aqueduct is often referred to as the Kankakee Feeder.

In the early 19th century, Aux Sable was a natural barriers to the construction of the I&M Canal. Because the creek is a natural watershed, the canal engineers had to construct an aqueduct over the creek. The Aux Sable Creek aqueduct is one of five aqueducts built along the canal as a solution to transporting canal boats over other bodies of water.

The Illinois and Michigan Canal aqueducts essentially were identical in terms of their basic construction components, such as abutments, piers, trunk and a towpath bridge, but varied considerably in respect to length.

Constructed in 1847, the first aqueduct at Aux Sable Creek was built as part of the original I&M Canal construction project. This wooden aqueduct was replaced in 1927-28 by a steel structure. In 1948, the abutments and piers were strengthened, and in 1970, the towpath bridge was rebuilt.

The aqueduct spans 136 feet across Aux Sable Creek and is 18 feet wide. The steel aqueduct again was stabilized as part of infrastructure improvements done along the canal in the late 1990s.