Report on River Restoration in the Pacific Northwest – Evolving Perspectives that Extend Beyond the Channel
Gardner Johnston, Hydrologist, MS, CFM
River Restoration Northwest Board member and Past President
Inter-Fluve, Inc.
Hood River, OR
Steep mountain streams, big wood-filled alluvial rivers, and salmon. That is what many picture when they think of river restoration in the Pacific Northwest (PNW). But the reality is much more complex. From Alaska to Northern California, from the coastal estuaries to the upper Columbia and intermountain West, we have an amazingly diverse landscape. Accordingly, we have a range of issues and impacts, and also a range of approaches towards restoration. Our practices also continue to evolve, with new innovations that reflect our broadening understanding of stream ecosystem function.
Over the past two decades, there has been a strong emphasis on recovering threatened and endangered salmonid populations, and much of the funding for restoration is related to recovering salmon listed under the Endangered Species Act. However, there is also a growing understanding of the impacts affecting other species, including lamprey, sturgeon, mussels, and amphibians. We are also now considering new stream stressors – climate change, sea level rise, increased flood risk, and catastrophic wildfire to name a few. Social and cultural factors are also increasingly integrated with restoration. This is especially true with Native American Tribes and First Nations, which have become leaders in river restoration and salmon recovery in the PNW.
Traditional river restoration approaches of bank stabilization and habitat creation are still alive and well in the PNW – and while they have their place, there is an ever-increasing focus on addressing the impaired ecological processes that result in degradation in the first place. This shift in focus is a frequent discussion in the PNW stream restoration community, leading to healthy debate on what exactly ecological process restoration means and how to achieve it. These discussions are leading to innovations and important progress in restoring the drivers and function of systems, rather than form-based approaches that only target symptoms. With this switch in perspective, we’ve seen an increase in consideration of biological processes and species interactions. Sediment transport and hydraulics remain foundational but are increasingly evaluated with respect to how they affect biology, and how biology affects them. We are continuing to explore and learn about the importance of floodplains, not just to dissipate flow energy and store flood water, but as the productive food sources for our aquatic species. We have seen a corresponding evolution of stream restoration design, from the focus on a single sinuous channel, to two-stage channels, to channels with floodplains, and now to floodplains with channels. The questions now are less about whether to take a function-based approach but are instead about how to accomplish it within the increasingly novel ecosystems and human constraints on the landscape.
About Gardner Johnston, MS, CFM
Gardner has been practicing river analysis and restoration design for 24 years. Gardner has a Bachelor’s degree in Biology from the University of North Carolina at Chapel Hill and an MS in Forest Engineering and Hydrology from the University of Washington. Gardner’s river science career began at a Conservation District in Washington State in 1996, where he coordinated watershed councils and first performed river habitat restoration projects. Since 2002, Gardner has worked as a consultant, with the past 15 years at Inter-Fluve where he is a Principal Hydrologist. At Inter-Fluve, Gardner leads interdisciplinary teams to accomplish restoration planning, assessment, and design projects. Gardner is a recent past President of the River Restoration Northwest (RRNW) Board of Directors, and has served on the RRNW Board since 2016.