Loveland, CO
The Big Thompson was dramatically impacted by the floods of 2013. Situated at the mouth of the canyon, the Sylvan Dale Ranch property was particularly devastated by flood flows but also by the volume of sediment that was deposited during the event. ERC was contracted by the Big Thompson Watershed Coalition to restore the channel using a design/build approach. Work was required to improve watershed resiliency and protect vital infrastructure while improving flood conveyance, sediment transport, and aquatic and terrestrial habitat. Our design utilized natural channel concepts. A multi-stage channel that optimized habitat under low flows and accesses flood terraces was created. Riffle/pool/glide features were created within the channel to provide diversity and channel stability. Overbank grading was used to increase conveyance and protect structures. Where needed, banks were stabilized with a variety of techniques ranging from softer cobble toe protection to soil filled riprap planted with willows. Throughout the project, ERC complied with requirements of the DOLA process including Davis-Bacon wages, certified pay, postings, Section 3 reporting and employee interviews. The project was successful at restoring a heavily impacted river segment utilizing natural design principles.