Project: Water Typing Strategy - Potential Habitat Breaks (PHB) and Default Physical Criteria (DPC)

This project is actively seeking participation from landowners associated with identified study streams. Did you receive a letter notifying you of a study stream on your property and requesting site access? If so, please fill out our access agreement form here: https://forms.office.com/g/ZvNj6HyJLM

Thank you for your participation!

If you have questions about the study, please reach out to Project Manager: Anna Toledo (anna.toledo@dnr.wa.gov). A presentation on this project is available here: https://www.wafarmforestry.com/DNRFishHabitatStudy

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The Potential Habitat Breaks (PHBs) and Default Physical Criteria (DPC) studies are separate studies that share a combined field effort. This work will test and refine criteria for the accurate identification of PHBs and DPC for fish habitat.

The purpose of the PHB study is to develop criteria for accurately identifying PHBs and to evaluate the utility of PHB criteria for use in the Fish Habitat Assessment Methodology (FHAM) as part of a water typing rule. The study is designed to assess which combinations of gradient, channel width, barriers to migration, and other physical habitat and geomorphic conditions are associated with uppermost detected fish locations. This will:

1. Inform which Board-identified PHB criteria most accurately identify the upstream extent of fish habitat in an objective and repeatable manner as applied in the FHAM and
2. Evaluate whether an alternative set or combination of empirically derived criteria more accurately achieves this goal.

Additionally, this study is intended to provide insight into how uppermost detected fish points, upstream extent of fish habitat based on FHAM, and PHBs proposed by the Washington Forest Practices Board may vary across geography, seasons, and years. The Board is expected to use the study findings to inform which PHB criteria to use in FHAM.

The purpose of the DPC study is to assess the current (WAC 222-16-031(3)(b)(i)) and alternative default physical characteristics used to define DNR stream types as Type ‘F’ or ‘N’ in situations where fish use is not determined using Board approved protocol electrofishing survey (PES) methods. Research will focus on the need to:

1. Compare and quantify how the current DPC correspond to the uppermost point of fish presence and potential fish habitat,
2. Determine the stream physical characteristics of habitat likely to be used by fish, and
3. Determine if sustained gradient or stream size thresholds alone could serve as default physical criteria.