The primary purpose of a breakup ice control structure (ICS) is to retain a breakup ice run upstream of a traditional ice jam problem area and thereby mitigate ice-jam flooding. By controlling ice-jam location, breakup ICSs also can prevent ice-related scour associated with dam removals or contaminated sediment remediation projects. This report briefly describes basic ICS types, purposes, and advantages and disadvantages, and provides engineering design guidance for their use. The use of numerical and physical models to design these structures is illustrated through case studies. The report includes a checklist to help designers compile the necessary input data and to conduct the analyses needed to ensure successful designs.