Engineering Aspects of a Saline Wetland Restoration Site

A multi-disciplinary approach was used to design a saline wetland mitigation bank for The Burlington Northern and Santa Fe Railway Company (BNSF) to compensate for unavoidable wetland impacts associated with the upgrade and expansion of their Hobson Yard facility in Lincoln, Nebraska. The project was the first permitted mitigation bank in Nebraska. Development of the design concepts centered around a hydrologic analysis of the proposed 178.60-acre mitigation site to determine an appropriate water budget and source of saline conditions for support of the desired biological communities. Mitigation measures to restore the area's past hydrology included construction of low-level earthen embankments with outlet control structures, correction of headcut drainages, removal of drain tile systems and other agricultural practices, and clearing of woody vegetation. These measures serve to correct hydrological and land management parameters that are actively degrading the site and thereby allowing the existing saline wetland plant communities to expand into a larger area generally thought to correspond to the historic coverage of the wetland. The plan included consideration of long-term maintenance and operation of the site for continued success of the project.