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Hennepin Canal Aqueduct #8



The Hennepin originally had nine aqueducts -- concrete troughs which carried the canal and its traffic across larger rivers and streams. Today, six remain the other three are replaced by pipes that carry the canal flow under the creek or river the aqueduct crossed over.

Time frame for replacement of aqueducts with siphons 

excerpted from American Canal Society website


The Hennepin Canal was first suggested in 1839 by Joseph Galer, a former construction superintendent on the Ohio and Erie Canal, and by Dr. Augustus A, Langworthy, a land speculator. Its construction was urged, in varying degrees of intensity, by local interests for the next 50 years………

The U. S. Army Corps of Engineers began construction in 1890. When completed, it was the first canal in America to be built entirely of Portland cement - concrete; the artificial stone was substituted for traditional cut stone facings in the canal’s locks and dams. The Hennepin, then called the Illinois and Mississippi Canal, was operated from October 24, 1907, until July 1, 1951, as a navigable commercial waterway by the Rock Island District of the Corps of Engineers………

After lengthy deliberations and renovation by the Corps of Engineers, the canal was transferred to the State of Illinois under the stewardship of the Department of Conservation on August 1, 1970. It is now part of the Hennepin Canal Parkway State Park.

There are 33 locks on the canal. All are still visible, but the one at the Illinois River has been partially back flooded since the 1930s. There is a lock at the head of the feeder and 32 on the mainline. All are manually operated with ordinary mitre gates, except for 14 with “Marshall” upper gates……

The canal included 9 aqueducts, 8 on the mainline (of which 5 remain)………

In the 1950's, one Marshall gate lock and 4 ordinary type locks were restored, but are not operated. The others were converted to spillways at their upper ends to maintain a 5 foot depth. The original depth of the canal was 7 feet………

Also, three of the aqueducts on the mainline were replaced by siphon culverts.

The usual width of the canal is 50 feet at the bottom and 80 feet at the original waterline. The canal included a towpath, but normally steam or diesel powered craft were used. In addition, there are several vertical lift bridges and several horizontally moving bridges of interesting designs.


Lost Aqueduct over Green River on Hennepin Canal
Henry County, Illinois
Removed. Replaced with pedestrian bridge to carry trail over river
Built between 1892-1907
Concrete trough on concrete piers
Also called
Green River Aqueduct
Approximate latitude, longitude
+41.47870, -90.30475   (decimal degrees)
41°28'43" N, 90°18'17" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/725037/4595406 (zone/easting/northing)
Quadrangle map:
Green Rock
Inventory number
BH 50015 (Bridgehunter.com ID)

Update Log 

  • June 3, 2015: Essay added by Gene Smania
  • November 3, 2011: Added by Steve Conro



Hennepin Canal Aqueduct #8
Posted February 28, 2015, by Ross Rudsell (therud53 [at] gmail [dot] com)

Hi,trying to find out when aqueduct #8 was removed from Colona Il.area.....Thank you for any info...Ross