Workgroup advances feasibility studies for point‑of‑diversion fish screens and constructed wetlands; streamflow grant deadlines approach

Clallam County staff and project partners outlined near‑term feasibility work for fish screens at the Highland Irrigation District headgate and a separate constructed‑wetland study intended to re‑time low flows for salmon.

Emily (DFW), a new member of the fish‑passage and screening team, said the headgate has automation and bypass problems that can strand adult fish and cause water loss. She described a point‑of‑diversion feasibility study being readied for funding that will test multiple intake and screening configurations and evaluate costs and fish‑safety performance.

"We're looking at multiple options and the costs associated with installing something here," Emily said, and asked the group for letters of support. Rhianna Barkey, the county project coordinator, said the county circulated a draft scope of work for the five‑month feasibility study and is collecting feedback.

Dave Rice (Anchor QEA) and HDR consultants described the proposed scope: a virtual kickoff, site visit and geomorphic field investigation; concept development with up to four configurations; hydraulic modeling to test depth and velocity; and memoranda and PowerPoint deliverables. The team emphasized site visits to identify constraints and to select screening technologies that meet fish‑passage criteria.

Separately, Jason (Washington Water Trust, subbing for Patrick) presented a constructed‑wetland concept and said the streamflow grant application for a feasibility study is due March 17. He described two approaches—floodplain wetland enhancement on adjacent parcels and a constructed wetland that could store and slowly release water timed to salmon migration—and said earlier rough modeling suggested potential benefits in the range of about 2.4 to 7 cubic feet per second for a portion of the season under optimistic assumptions.

Jason estimated the constructed‑wetland feasibility study budget at approximately $500,000–$650,000 to cover two seasons of data, piezometer installations, monitoring wells and infiltration testing; the study would refine benefit estimates and timing of release mechanisms.

Jamestown S'Klallam representatives said the tribe will sign a landowner acknowledgement and prepare a letter of support, though fish biologists expressed some skepticism about the wetland strategy and asked the study to address those concerns. Nate White (DFW) offered to coordinate receipt of letters of support from DFW.

Next steps: finalize the amended Ecology scope for the point‑of‑diversion feasibility study (county seeks buy‑in from co‑managers, the Jamestown S'Klallam Tribe and the headgate owner), finalize the constructed‑wetland scope and budget and submit the March 17 streamflow grant application. Staff also noted the county holds Ecology construction offers (~$4 million across 2020 and 2022 rounds) that could support construction if designs and permits are completed.