Mississippi River Lock and Dam 5a, located in Winona, Minnesota, is a vital structure managed by the US Army Corps of Engineers for the primary purpose of navigation, with additional benefits for recreation. Completed in 1936, this concrete dam stands at 46 feet high and spans 21,520 feet in length, with a capacity to store up to 260,000 acre-feet of water. The dam plays a crucial role in managing water levels along the Mississippi River, with a controlled spillway width of 575 feet and a maximum discharge capacity of 268,000 cubic feet per second.

With a significant hazard potential, the dam is subject to regular inspections and risk assessments to ensure its structural integrity and effectiveness in flood risk management. The US Army Corps of Engineers actively monitors and addresses all types of flood risks associated with the dam, working closely with local emergency managers and the public to raise awareness and develop emergency action plans. Continuous maintenance and repairs are carried out to uphold the dam's functionality and readiness for potential emergencies. As a critical component of the regional water resource infrastructure, Mississippi River Lock and Dam 5a serves as a key player in maintaining the safety and stability of the surrounding areas amidst varying hydrological conditions.