Nebraska Highway 12 near the town of Niobrara, runs parallel to the Missouri River. The distance between the highway and the bank of the river is only 2,000-3,000 feet in some areas, with standing water covering much of the area between the highway and the river. Water levels in the area have been rising due to the silting of the river, resulting in periodic flooding of the highway.
Benesch assisted NDOT in the wetland delineation and section 404 permit for two proposed alignments for Highway 12. The NEPA environmental review requires that several alternatives be evaluated. Benesch deployed three two-man teams to survey wetlands and waterways along two different proposed alignments. Each alignment was approximately 13 miles long. Field crews surveyed for 3.5 weeks to complete delineation. Findings were documented in a wetland delineation report.
Benesch is also assisting NDOT in planning and roadway design. Benesch has prepared conceptual designs for approximately 12 miles of rural highway to be raised an average of eight feet. NDOT is currently evaluating the alternatives to determine which will be carried forward to final design. Other services that Benesch provided was a hydrology and hydraulics study and geotechnical exploration to provide recommendations for subbase stabilization.