Design and construction observation was provided for the conversion of a ditch to a meandering stream channel that feeds a new extended detention wetland with an iron-enhanced sand filter to protect Lake Irving in Bemidji, MN. HR Green performed a feasibility study, a construction plan set, acquired Clean Water Legacy funds for its implementation, and provided construction engineering services. The project was successfully completed.
The project provides new fisheries habitat, significant pollutant load reductions to the impaired lake, and improves aesthetics for the surrounding open space scheduled for residential development in the near future. The ditch valley was widened to create a meandering Type-E channel through a wet meadow. The new extended detention basin and iron-enhanced sand filter significantly reduce phosphorus and sediment yields to Lake Irving and help the City of Bemidji move towards meeting its waste load allocations.
