Hackberry Flat is a natural, 4,000-acre depressional wetland in southwest in Tillman County near Frederick, Oklahoma. In the early 1900s, residents drained the entire basin after excavating an extensive ditch over five years. For the next 80 years, the basin was altered by agricultural conversion, development of a county road system in the 1930s and additional drainage development. In late 1992, the Oklahoma Department of Wildlife Conservation (ODWC), Ducks Unlimited and others initiated plans to acquire and restore this historic basin.

By the late 1990s more than 95 percent of the historic basin had been acquired by ODWC. Through development of a comprehensive network of nearly 60 miles of low-level dikes and the installation of more than 90 water-control structures, the basin's hydrology was restored. Today, the 7,120-acre wildlife management area consists of approximately 3,700 acres of basin and related buffer lands intensively managed for waterfowl and other bird species.

Over the last 20 plus years, due to natural salinity levels and naturally occurring wet/dry cycles, several of the steel water-control structures corroded, and some failed. We now need to replace these structures to control the water surface elevation on roughly 700 acres. Four degraded water-control structures will be replaced with aluminum structures, which are more resistant to corrosion. DU completed a structure design and delivered plans and construction specifications to our partners at ODWC. ODWC will solicit bids for the structures and for installation.