LOCKPORT, Ill. - On Friday, Oct. 7, approximately 280 linear feet of Chicago Sanitary and Ship Canal concrete wall slid into the Canal. The wall is located just upstream of the Lockport Lock on the left descending bank. No breach of the Canal earth embankment behind the concrete wall occurred and no personnel were injured or equipment damaged.
Engineers from the U.S. Army Corps of Engineers, Rock Island District, performed an immediate dam safety inspection to determine safety and the possibility for earth embankment failure. The inspection included a review of drawings, analysis, and a detailed visual inspection of the entire embankment at the collapse site and immediately upstream and downstream of the affected area. The assessment determined that failure of the remaining Canal earth embankment is not probable but remains possible.
Preliminary assessments by Corps engineers indicate that if a breach failure of the Chicago Sanitary and Ship Canal earth embankment were to develop, the release of Canal pool water would not cause any adverse downstream impacts. The water would likely empty into Deep Run Creek, follow the Deep Run Creek channel to the confluence of Deep Run Creek and the Des Plaines River, approximately 0.25 miles downstream of Lockport Lock, and under normal operations all Canal waters would likely be contained within the Des Plaines River. However, a sudden release of water could result in a rapid drop in the upstream Lockport navigation pool on the Chicago Sanitary and Ship Canal. Such an event could impact public safety and damage craft on the Canal.
Seven concrete monoliths on the face of the Canal wall (approximately six-feet thick and fifteen-feet from the top of the wall) sheared off into the Canal. The incident occurred near construction work to protect two miles of Chicago Sanitary & Ship Canal concrete wall with the installation of pre-cast concrete panels. The work is part of a $110 million multi-stage construction project which also includes constructing a 4,300 feet cut-off wall (completed in FY09); and repairing concrete bulkheads and replacing brick, limestone and granite facades to the Lockport Controlling Works (under construction).
On site, 24-hour monitoring and assessment of the Canal wall and embankment continues and most work activities associated with the Canal wall rehabilitation will continue in the near future. If any potential failure of the Canal embankment is determined to be probable, mitigation actions will be implemented including additional emergency management and public notifications.
A 50-foot construction buffer zone is in place requiring commercial navigation traffic to limit barge widths to 70 feet wide, 600-feet long until further notice. Tows are also required to operate at a minimum safe speed in the lock area and to the immediate north of Lockport Lock to reduce propeller wash and wake.
Release no. FY12-10-01