Left Hand Creek Flood Recovery and Restoration Boulder County, Colorado

After Colorado’s 2013 flood, the state received funding from the Natural Resources Conservation Service Emergency Watershed Protection Program to address extensive damage to homes, businesses, and road infrastructure.

A Reconnected Floodplain and Restored Stream to Mitigate Future Flooding

During the flood, high sediment loading quickly plugged undersized culverts at road crossings and caused threatened life and property. Improvements included floodplain reconnection, restored riffle-pool and step-pool sequencing, offset protection at critical assets, bank stabilization, and native revegetation. Public stakeholder meetings facilitated discussions with property owners, completed 1D and 2D hydraulic modeling, and provided sediment transport analyses to meet technical design and floodplain permitting requirements. This project has made the area much safer for its residents, with resiliency protections, reduced flood risk, and stream health improvements. The river will perform better during future floods with reduced damage and faster recovery time. Working closely with Lefthand Watershed Oversight Group and property owners, Otak led the analysis and design for this high-visibility project and provided construction support.