Coon Creek 23, also known as Opsahl/Blihovde, is a local government-owned dam located in Monroe, Wisconsin. Constructed in 1961 by the USDA NRCS, this earth dam serves the primary purpose of flood risk reduction along the Un Trib Rullands Coulee Creek. With a height of 39 feet and a hydraulic height of 25 feet, the dam has a moderate risk assessment level of 3 and a low hazard potential.

Despite being state regulated and permitted by the WIDNR, the condition assessment of Coon Creek 23 is currently marked as unsatisfactory, with the last inspection conducted in May 2016. The dam has a storage capacity of 95.5 acre-feet and a maximum discharge of 368 cubic feet per second. While the dam's spillway is uncontrolled, the risk management measures and emergency action plan for the structure are not currently available. Overall, Coon Creek 23 presents an intriguing case study for water resource and climate enthusiasts, highlighting the importance of ongoing maintenance and assessment for dam safety and flood risk reduction efforts.