Removing a Dam and Building Back Habitat and Water Supply on the Hoquiam River

Over the last 20 years, the City of Hoquiam has worked towards both removing their West Fork Hoquiam River Dam (used as a surface water diversion for City water supply) and replacing the City’s water supply with groundwater wells. The City and other local stakeholders want this nearly 70-year-old dam removed for a number of reasons – it’s aging past its design life, it blocks salmon habitat, and replacing the City’s water supply with groundwater wells will improve the water supply and water quality for the City’s customers. In 2023, predesign and feasibility is underway -- with help from a $1.2 million grant from NOAA -- and actual dam removal anticipated within the next five years.

Dive deeper into the exciting progress in the accompanying Story Map for this project.

20+ Years in the Making: Levee Sparks Dungeness River Restoration

On the Olympic Peninsula in Northwest Washington, the Lower Dungeness River Floodplain Restoration project restores habitat and natural river processes that are confined by various levees and dikes constructed in the 1940s through 1960s. The lower reaches of the Dungeness River have been constricted on the right bank by an existing 2.4-mile-long levee built in the 1960s by the United States Army Corps of Engineers (USACE). However, the USACE levee is ‘under-designed’ for anticipated flood events to come.

Aerial view of the 2,600-foot setback levee

Photo credit: Jamestown S’Klallam Tribe (JST)

Twenty years ago, the Lower Dungeness River Floodplain Restoration project was conceived with the goal of building a new setback levee and reconnecting the Dungeness River with its historical floodplain; improving habitat conditions; and restoring riverine processes and functions. The project was split into two parts: the Clallam County (County) levee setback project from River Mile (RM) 0.8 to 1.75, and the River’s Edge Project between RM 1.75 to 2.7. The County project started in 2015, but then the floodplain restoration work hit a standstill – until the Jamestown S’Klallam Tribe (JST) brought the River’s Edge Levee Setback project to life.

Jamestown S’Klallam Tribe Rebuilds a Floodplain to Restore the Region

For thousands of years pre-colonialism, the JST nurtured the land and many saltwater bays and freshwater rivers. Today, the JST takes an active role in community environmental projects, including participating in the Dungeness River Management Team and implementing habitat restoration projects such as this levee project, which is a part of the Lower Dungeness River restoration efforts.

JST purchased farmland along this stretch of the Dungeness River (with a strong show of support from local community members) with the understanding that the purchased land would be used for conservation efforts. JST secured funding support from Washington state’s  Floodplains by Design grant and brought on Engineering Services Association (ESA) to lead the project design. ESA in turn brought Aspect in to be the geotechnical lead, as well as several other key team members like WEST Consultants (hydrology and hydraulics) and Johnston Land Surveying.

The River’s Edge project will renew historical riparian habitat and boost the overall health of the ecosystem, including salmon recovery for key species like Chinook salmon, summer chum, bull trout, and steelhead. The new setback levee will also double as a walking path to be used by all members of the community.

Early Detective Work in a Floodplain Leads to Success

Rivers deposit soils in highly varied and complex ways. To set up the 2600-foot-long setback levee for success and understand the subsurface conditions, Aspect led a two-phase subsurface exploration program that included six soil borings (2 with vibrating wire piezometer installations), 11 test pit excavations, 13 hand-dug explorations, and 4 cone penetrometer explorations. Using this information we created a profile of subsurface conditions to power smart levee design.

Levees Need to Be Made of the ‘Right Stuff’

Nearby gravel pit that ‘fed’ the levee

Photo credit: Krazan & Associates

A key driver in any levee project is the availability of material. This levee was made up of over 37,000 cubic yards of gravel and sand. ESA identified a material source only two minutes away and Aspect and ESA tailored the levee design to make sure the material available from the gravel pit could be successfully used to build the levee to meet design standards. Having a material source so close to the Site helped save budget, time, and greenhouse gas emissions.

Finishing a 2,600-Foot Levee in Under Two Years: A Win !

Floodplain restoration without River's Edge Levee Setback project (on the left) and WITH River's Edge Levee Setback Project (on the right).

Photo credit: North Olympic Land Trust

Aspect collaborated with ESA, JST, and USACE to design the setback levee in just under one year, with construction of the project hot on the heels of the final design submittals. Construction then started and the new setback levee was built in just over 2 months!

In summer 2022, the existing levee will be removed to allow the Dungeness River to reclaim 56 acres of floodplain. The Clallam County project will eventually tie into the River’s Edge Setback Levee to open up an additional 87 acres for a combined 143 acres of reclaimed historical floodplain and habitat for salmon, birds, and wildlife.

The hard work and dedication of the River’s Edge project team helped realize the JST’s desire to create a quality setback levee that meets the latest and greatest safety standards, within their desired schedule – and underbudget!

Robyn Pepin Talks Fish Passage Barrier Prioritization on GIS Podcast

Senior GIS Analyst Robyn Pepin was recently a guest on the GIS-focused podcast Will We Make it Out Alive?

In an episode titled “A Culvert Affair,” hosts Amy and Jen talked with Robyn about the Fish Passage Barrier Prioritization Tool she developed for the Upper Salmon Recovery Board to prioritize which culverts and other obstructions blocking fish passage should be removed first, and how she continues to adapt and improve it as needed for other agencies. Robyn also walks listeners the Flow Network tools she used to create the tool.

Listen to Robyn and other episodes of the podcast here.

New GIS Tool Helps Remove Barriers to Salmon Habitat Connectivity

Clean, cold water. Lush riparian vegetation. Gravels for spawning. These are some of the elements that create healthy habitat for salmon. The Upper Columbia region has some of the best in the Pacific Northwest. Unfortunately, not all of this habitat is within the salmon’s reach. Removing barriers such as culverts and dams is a top priority for salmon recovery goals, but there are thousands of barriers, limited resources to remove them, and a diverse group of stakeholders with issues to address. What everyone wants to know first is: how do we decide WHICH barriers to remove?

Instream barriers such as culverts like this can limit fish passage to available habitat.

Enter a New Tool for Fish Habitat Decision Making

In partnership with the Cascade Columbia Fisheries Enhancement Group, the Upper Columbia Salmon Recovery Board, the Upper Columbia Regional Technical Team (RTT), and a technical steering committee, Aspect created a GIS-based decision support tool that summarizes the overall quality of ecological conditions surrounding each instream barrier within the Wenatchee Basin. This custom spatial model provides insight into critical questions regarding barrier-removal priority:

  • Is there habitat available upstream from the barrier that salmon currently cannot access?

  • Is that available habitat of sufficient quality for salmon?

  • Is there known fish usage near the barrier already?

  • Are there barriers downstream blocking fish access?

This prioritization tool provides salmon-recovery stakeholders with a common approach to answer these questions. The variables under consideration at a barrier—upstream habitat quality, local stream temperature, connectivity to other barriers, etc.—each receive a score. Those scores are then added up to a total priority tier ranking for that barrier. By assessing each barrier through this scoring process, we’ve created an actionable apples-to-apples comparison of habitat benefits associated with barrier removal.

A preview of barrier removal ranking priority data.

A Tier 1 ranking indicates the top priority for removal, indicating more biological benefit gained from a barrier’s removal. Tier 4 ranking is the lowest priority ranking, indicating little biological benefit gained from a barrier’s removal. UCSRB and the RTT use these categories to guide decisions on proposed project funding. The rankings are updated as available data sources improve.  Preview the results HERE. This tool will allow stakeholders to align and coordinate their barrier removal work towards the larger common goal of salmon-habitat connectivity within the Upper Columbia and throughout the state.

If interested in adapting this tool for your project and/or basin(s), contact Robyn Pepin for more information.

ETA (6/3/2019): Robyn Pepin and Taylor Rulien’s poster for this GIS tool won best analytical data presentation at 2019’s WAURISA Conference. Check it out here.

Removing Barriers to Fish Passage at Icicle Creek

Like many of Washington’s waterways, Icicle Creek in Chelan County is the site of several projects with the goal of helping salmon and other fish make their way upstream to spawn. Many of the projects involve constructing structures, like a habitat-friendly culvert or a fish ladder, to balance fish passage with the many other needs and uses for the river. But a project sponsored by Trout Unlimited is focused on removing barriers—in this case, large boulders in the creek that stand in the fish’s way. Once the boulders are removed, fish will have access to another 26 miles of habitat.

This project is one of a suite of projects the recently released Icicle Programmatic Environmental Impact Statement (PEIS) recommends in the Preferred Alternative to implement the Icicle Strategy, an $82 million dollar effort to ensure a sustainable water supply and water resources for people, farms, and fish in the Wenatchee Basin through 2050. Aspect has been the technical and facilitation lead on this project since 2012. Our work includes serving the Icicle Work Group—a group of approximately 30 stakeholders from local, state, and federal governments, Tribes, irrigation districts, farmers, and non-profit groups that created the Icicle Strategy; developing the PEIS; and leading technical evaluation of proposed projects across the basin that may improve water resource management and increase instream flow during critical flow periods.

Senior Geotechnical Engineer Nick Szot, PE, and Senior Engineering Geologist Mark Swank, LEG, are supporting Trout Unlimited’s goals for the Icicle Creek project by developing alternatives for fish passage and relocation of a 16-inch-diameter watermain that brings water to the City of Leavenworth. They have also provided considerations for protecting creek bank slope stability during construction, which is expected to start in summer 2020.  Learn more about the project in this recent article in the Wenatchee World.