After continuous flooding, the City of Dyersville made a commitment to improve stormwater quality of Bear Creek, a tributary the North Fork of the Maquoketa River, which converges and flows through Dyersville.
Partnering with Origin Design and Impact7G, the City wanted to modify the stream corridor to improve water quality and habitat while decreasing flood effects where possible. Working together, Origin Design and Impact7G designed improvements meeting Iowa DNR Stream Restoration criteria.
Origin Design conducted a stormwater Restoration Feasibility Study to define a Citywide master plan. From the plan, the Iowa DNR approved the ¼-mile long stretch of Bear Creek in Westside Park for the first phase of restoration using State Revolving Funds (SRF).
Throughout the duration of the project, invasive Japanese Knotweed was identified on site. The plant stems and root balls were removed to curb further spread. Additionally, components such as rock riffles, linear deflectors, vanes, j-hooks, inner berms, and rock sills were added to the stream to provide a stable stream environment. Wet & dry oxbows were utilized to help catch sediment. Channel shaping and reducing stream width helped to improve overall water quality. Existing limestone was removed and relocated throughout the stream as a cost-saving mechanism.