Planning implementing & evaluating valley bottom restoration: lessons from the Grande Ronde

Year: 2023
Presenter/s: Phil Roni
Symposium Session: 2023 - 09 - An Open Toolbox: Tools and Assessments to Tackle Complex Questions
Topics covered: adaptive management and monitoring, fish-salmon, hydraulics, lessons learned, and modeling


ABSTRACT

The restoration of floodplain habitats is now one of the most common approaches to restoring a variety of ecological and ecosystem services and increase habitat capacity and recovery for Endangered Species Act (ESA) listed salmon and trout. Restoring floodplains or entire valley bottoms for a reach or valley segment to historically anastomosing channels, often called “Stage 0” or valley bottom restoration, has become increasingly common in the Pacific Northwest of North America. To ensure Stage 0 restoration is successful, applied in the right locations, and not the latest costly watershed restoration technique applied inappropriately, some additional guidance is needed. Therefore, using lessons learned from planning and implementation of valley bottom restoration projects designed in the Grande Ronde River Basin in Northeast Oregon, we outline the key steps and decisions needed to plan, design, implement, and evaluate a successful valley bottom restoration project. We first define Stage 0 channels and restoration, detail how it compares to common channel typing systems, and identify natural anastomosing channels in the Grande Ronde Basin to assist with designing Stage 0 restoration projects. We then discuss how to identify potential sites for valley bottom restoration including historic, current, and potential for Stage 0 channels. Next, we discuss key considerations for project design and implementation including hydraulic modeling, habitat suitability modeling, and other tools that also assist in setting objectives and monitoring and evaluation criteria. Finally, we provide examples of planning, design, monitoring and evaluation of Stage 0 restoration projects to assist with adaptive management.