Restoration work has been completed and is now in the warranty, permit monitoring, and adaptive management phase. The location is along the St. Vrain Creek south of SH-66 between Union Road and N. 63rd Street and near the old “Breach 2” from the 2013 floods. The project created improved aquatic and riparian habitat while protecting infrastructure through enhanced floodplain connections and directing excess stream flow into improved main channel riffle and pool features. The diversion structure was made more robust through the use of buried sheet pile and the removal of a small dam feature was realized to enhance sediment and fish passage.
The intent of this project was to create a stable channel reach. The project concept was to re-design the existing upper bypass structure and downstream St. Vrain Creek channel to the intersection of the ditch supply channel return flow confluence. The project objectives included providing more continuous sediment transport and fish passage in the St. Vrain Creek channel, moving high energy water away from local ditch headgates, providing the decreed flows to the local ditches as first priority including stream sweeping, and mitigating future flood damage on local and downstream properties.
Additional objectives of this project included increasing floodplain connectivity to reduce the power of flood flows; increasing stream resiliency to recover from flood flows; incorporating native plant revegetation to support Preble’s Meadow Jumping Mouse (PMJM, Zapus hudsonius preblei); and using vegetation, habitat boulders and large wood to stabilize soils, increase channel and floodplain roughness, and increase topographic complexity.
The stream restoration approach and the ditch infrastructure protection targets are consistent with the larger vision for watershed and stream recovery as proposed within the St. Vrain Creek Watershed Master Plan.
Zak Dirt was the Contractor for this project, with Western States Reclamation as sub-Contractor for the vegetation installation.
Design work started in June 2019. The design team was led by Otak, Inc. with sub-consultants Ecos, Michael Baker International, Wright Water Engineers, King Surveyors, and Yeh & Associates.
Funding was provided by the U.S. Department of Housing and Urban Development’s Community Development Block Grant Disaster Recovery Program (HUD CDBG-DR) administered by the Colorado Department of Local Affairs and the Boulder County Collaborative.