Modeling Ice Passage at Starved Rock Lock and Dam on Illinois Waterway

Ice conditions hamper winter navigation on major U.S. waterways. Accumulations of broken ice in the upstream approaches to locks and dams can interfere with lock operations and hydropower production. Conveying this ice downstream through dam gates can be difficult because of the low water velocities found in pool areas, and the limited available discharge for ice passage during winter low-flow periods. A physical hydraulic model study, using real ice, investigated the design and operation of submergible gates for ice passage at the U.S. Army Corps of Engineers Starved Rock Lock and Dam on the Illinois Waterway. Alternative gate locations were tested for a range of gate discharges and ice conditions. The effects of hydropower diversions, navigation, and high-flow air screens on ice passage were examined. The study found that, under some ice conditions, submergible gates alone may not be adequate for ice passage. During these times, tow and barge transits through the lock and deflector bubbler operation would need to be coordinated with submergible gate operation to pass ice.