MORRIS, Ill. -- The U.S. Army Corps of Engineers Rock Island District is soliciting contract proposals for emergency scour repair work at Dresden Island Lock and Dam, 1-1/2 miles downstream from the mouth of the Kankakee River and approximately 15 miles southwest of Joliet, Illinois. Due to the urgency of this repair, the solicitation period is abbreviated to close on January 4, 2010.
During a recent inspection, scouring of limestone bedrock downstream of the Dresden Island Dam was discovered. The limestone bedrock is above a relatively weak shale formation that erodes more easily than limestone. The dam has not shown any movement and is being monitored for signs of distress. Due to the potentially weak nature of the underlying shale, it is necessary to complete repairs to ensure the integrity of the dam structure.
The probability of a catastrophic dam failure is very low; however, the consequences of such an event warrant the emergency repairs. The consequences of such failure would be a loss of the navigation pool, which could result in reduced or loss of water supply for fire demand and industrial uses such as cooling water. Impacts could also occur to boat harbors, some of which may need to be vacated. No major flooding downstream of the dam would occur due to a dam failure as river levels would remain below flood stage.
The repairs include mass underwater cold-weather concrete placement to prevent additional scour and add resistance to sliding. The repairs will be made in the water without the use of coffer dams surrounding the repair area. Approximately 10,000 cubic yards of fill/concrete may be required to complete the repair work estimated to cost less than $5 million.
Contractors interested in providing a proposal must visit www.fbo.gov, solicitation number W912EK-10-R-0020, to download the plans and specifications which will be available on or about December 21, 2009.
The Dresden Island complex opened in 1933 and consists of a gated concrete gravity dam. The total length of the lock and dam between abutments is approximately 1,320 feet. Lock dimensions are 110 feet wide by 600 feet long. The dam consists of an arch dam section, a fixed spillway section, nine Tainter gates (60 feet wide by 17 feet high), 18 plugged headgates, and a 500-foot-long earthfill section with steel sheet pile cut-off wall connecting the headgate section to the Illinois and Michigan Canal embankment.
Release no. 10-12-08