Wilkin County Bridge Replacements

Interstate Engineering has provided Wilkin County bridge design services for over 21 years. In that time frame, we have designed eight bridge replacement structures for them, including a bridge constructed in 2022. Several more hydraulic analyses for structure replacements were completed for projects that the Wilkin County Highway Department designed with precast box culverts as the preferred structure replacement. Each of these projects included coordination with the Northwest Region of the DNR to ensure the structures met DNR requirements.

Interstate Engineering completed recent hydraulic studies for Wilkin County on two short steel beam bridges over Rabbit River. Bridge L7352 was a 48-foot 2-span steel beam bridge with a cast-in-place concrete deck. Three bridge alternatives were analyzed, and the county selected a double 14-foot by 11-foot precast reinforced concrete box culvert structure. Bridge L7348 was a 38.5-foot single-span steel beam bridge on 220th Avenue SE with an ADT of 50. After the preliminary engineering and hydraulic analysis of three alternatives, the county selected a double 14-foot by 9-foot precast reinforced concrete box culvert structure. These structures required coordination with the Bois de Sioux Watershed District as both of these structures have drainage areas and peak flows controlled by the North Ottawa Impoundment project. Project hydraulics were completed to comply with Minnesota DNR and MnDOT criteria.