The union slough national wildlife refuge middle dike rehabilitation project will replace a failing water control structure and restore reliable water management within one of the refuges most…

The union slough national wildlife refuge middle dike rehabilitation project will replace a failing water control structure and restore reliable water management within one of the refuges most important wetland units. Located in north central iowa union slough NWR sits at the confluence of the blue earth watershed and the east fork of the DES moines river. This unique hydrologic intersection creates a diverse wetland complex that provides essential feeding resting and nesting habitat for thousands of migratory birds that move through the mississippi flyway each year.middle dike is approximately 1600 feet long and contains a cement box culvert with stoplogs used to manage water levels on both sides of the dike. The existing structure is deteriorating and will soon be nonfunctional if IT is not replaced. Losing the ability to manage water levels would severely impact habitat quality reduce food availability and limit the refuges ability to conduct seasonal drawdowns and reflooding that support moist soil plant production invertebrate abundance and brood rearing conditions for waterfowl. This project will remove the failing culvert and install a new reinforced concrete water control structure designed to meet modern engineering and hydrologic standards. Construction will include rebuilding and stabilizing the dike reshaping slopes adding erosion control features and placing protective riprap to ensure longterm durability. Once completed the upgraded structure will restore full control of hydrology within the wetland units and strengthen the refuges resilience to extreme weather and seasonal flooding.ducks unlimited in close coordination with the U.S. Fish and wildlife service through a cooperative agreement will oversee design implementation contractor management and construction oversight. USFWS will participate in all major decision points approve each stage of work before the next begins and maintain authority to halt any activity that does not meet performance specifications.by restoring essential water management infrastructure this project will enhance high quality wetland habitat support migratory bird populations and protect the ecological integrity of one of iowas most important wildlife areas for decades to come.