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Olsson Associates joins watershed protection team to assist Colorado flood recovery

Tuesday, January 17, 2017

Edie Adams, Marketing

Flood damage along the Big Thompson River.

Colorado’s 2013 floods were devastating for many municipalities across the state, particularly for those near or within the foothills of northern Colorado. Many roadways, bridges, and buildings were damaged or destroyed as a result of the intense flooding, streambank erosion, channel aggradation and degradation, and the lateral migration of numerous streams and rivers along the Front Range.

An emergency plan was needed to fix the damage. To coordinate the $63 million of Phase II mitigation projects needed, the United States Department of Agriculture Natural Resources Conservation Service (NRCS) implemented the Emergency Watershed Protection Program (EWP). It’s funded and administered by the NRCS and managed by the Colorado Water Conservation Board (CWCB) on behalf of the state. Under the program, the NRCS and CWCB released a request for proposals to assist in implementing watershed recovery projects. The projects would reduce risk to life and property, enhance riparian ecosystems, and generate long-term stream system resilience through a collaborative, watershed-based approach that incorporates the needs of diverse stakeholders.

Olsson Associates, as a team member of Resilient Watershed Partners, is providing the CWCB and local project sponsors with technical services to complete projects for the NRCS program. These efforts will help to achieve long-term objectives in watershed protection, restoration, and resiliency in Colorado. Resilient Watershed Partners is made up of local leaders in river restoration design, floodplain management, river ecology, and riverine construction support. Olsson is providing water resources, environmental, survey, and geotechnical services.

The EWP Program is a critical component in Colorado flood recovery and the efforts to provide the extensive protection and restoration needed. It will provide resiliency for the state’s communities, economies, and river systems. Resilient designs are the heart of the program. Its innovative treatments and approaches will provide safety and protect life and property by returning flood-affected areas to more natural and sustainable stream corridors. If possible, certain areas will be restored to pre-flood conditions. However, multiple areas exist where dramatic topographic and locational changes happened because of scour, erosion, deposition, and major channel shifts, which make it impractical to restore floodplains to previous conditions. Designs produced by the team must minimize impacts to environmentally sensitive areas through streambank and stream channel stabilization and provide protective measures.

Bill Spitz, a senior scientist on the project, has been involved with various flood recovery efforts since the 2013 floods. He assisted with assessments of the flood damage, evaluated emergency repairs, and recommended permanent repairs for major mountain highway corridors along the Front Range.

He states: “For me, what makes this project rewarding is that I will be able to go from serving as the team river morphology expert on the Colorado Department of Transportation flood damage assessment team immediately after the 2013 floods,  to being involved in designing and ultimately constructing resilient stream restoration and stabilization projects for several EWP Program sites along several of those same mountain corridors.”

The EWP Program projects range in size from less than an acre to thousands of feet of full channel and floodplain restoration design and construction. It’s all on a rapid timeline that must be completed by January 2018, while addressing uncertainties that include matching funding availability; federal, state, and local permitting requirements; no-rise certifications; data availability; and stakeholder and landowner approvals.

 

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