Left Hand Creek Restoration

Stability, resilience, ecology, and public safety and ecology are restored to a flood-damaged canyon in Colorado’s Front Range.

In the fall of 2013, a severe storm dumped 10-20 inches of rain along Colorado’s northern Front Range, causing severe flooding in the foothills, and wiping out Left Hand Canyon Road, a main road leading in and out of the mountains northwest of Boulder. The road follows the path of Left Hand Creek, a stream which begins on Niwot Mountain, runs through a canyon, and flows onto the plains, where it joins St. Vrain Creek and ultimately the South Platte River. During the storm, the Left Hand Creek suffered extreme erosion, deposition, and habitat degradation.

Working with AECOM, Biohabitats helped the Central Federal Lands (CFL) Highway Division of the Federal Department of Transportation enhance the resilience of both the road and creek. While CFL led the effort to relocate the roadway further from the creek, Biohabitats developed a design to restore stability and habitat to nearly 2.5 miles of the creek and its floodplain. Biohabitats began by conducting an assessment of the entire project reach and prioritizing restoration reaches. Despite the challenges of working in a canyon with limited floodplain area and an adjacent roadway, Biohabitats recognized many opportunities to increase the floodplain and incorporate aquatic habitat features, such as riffles, pools, and woody debris, which had been removed by the flood. Biohabitats produced 30% construction plans and worked closely with the grading contractor during construction, ensuring implementation of design intent and making adjustments to the channel design, as needed. Biohabitats was onsite for over three months providing construction oversight.