Aquatic Species Restoration Plan Research and Studies

The Chehalis Basin Board, Ecology's Office of the Chehalis Basin, Washington Department of Fish and Wildlife, along with the Quinault Nation and Chehalis Tribes work in concert to fund studies within the Chehalis Basin. These studies help create and inform the Aquatic Species Restoration Plan (ASRP) for the Chehalis Basin. This science-based plan is designed to help restore and enhance aquatic species habitat and improve local communities. It was designed to efficiently and effectively rebuild and protect a healthy ecosystem that is resilient to the effects of climate change.

The Chehalis Basin and its rivers and tributaries are facing many simultaneous challenges:

  • Declining returns of spring-run chinook salmon, and other native salmon and steelhead trout populations
  • Shifts in weather patterns due to climate change, including drier summer weather patterns, low streamflow, and warmer water temperatures
  • Loss of critical habitat affecting native fish, mammals, amphibians, birds, and other species
  • Competition from non-native and invasive species

The Aquatic Species Restoration Plan, Phase I publication.

The ASRP is both a living document and plan for the Chehalis Basin. In 2019, we released Phase 1 of the ASRP. It is envisioned that there will be multiple revisions of this plan adjusting to feedback from further monitoring and scientific studies. The Chehalis Basin Board will use this plan to guide ongoing and future habitat and species restoration and enhancement projects within the basin.

Research and studies

There are three types of studies for ASRP: measuring project effectiveness, monitoring status and trends, and testing hypotheses and assumptions through experimental research. These studies help us determine how well the ASRP is meeting its goals and what changes need to be made for futher improvements for habitat and aquatic species populations.

The ASRP has many studies, past and present, to track the status of the Chehalis Basin. To make it easier to find information we have grouped the studies by the following categories:





Native and non-native fish

Mammals, birds, and other wildlife

Climate and culverts

Experimental restoration

Data sources

Data on water, fish, and more is abundant in the Chehalis Basin. Many databases allow searching by Water Resource Inventory Area (WRIA). The Chehalis Basin encompasses two WRIAs — WRIA 22 (Lower Basin) and 23 (Upper Basin). The links below include several useful data sources for the Chehalis Basin.

Department of Ecology

Washington Department of Fish & Wildlife

  • Salmonid distribution, passage barrier, and major facilities, plus Endangered Species Act (ESA) listings:
  • Salmonid population estimates (escapement) and hatchery production:
    • SCoRE
      • In addition to the web interface, the data can be retrieved directly from

Thurston County

University of Washington