2020-2021 public meetings

Starting in fall 2020, the Office of Chehalis Basin hosted a series of public meetings to connect with and hear directly from Basin residents and others on the choices related to reducing flood damage and restoring aquatic species habitat that will impact the future of the Chehalis Basin.

Learn more by viewing the meeting recordings and presentations from the public meetings:

• Public Meeting #3: March 9, 2021: View the meeting recording | View the meeting presentation
• Public Meeting #2: February 17, 2021: View the meeting recording | View the meeting presentation
• Public Meeting #1: November 10, 2020: View the meeting recording
• Frequently Asked Questions (FAQ): View the FAQ summary from the meetings

2019-2021 biennium studies

• Local Actions Program Advisory Group Materials
• Chehalis Basin: Extreme Precipitation Projections (UW Climate Impacts Group, Feb 2021)
• Erosion Management Strategy in Priority Erosion Hazard Areas (Anchor QEA, March 2021)
• Initial Historical Channel Mapping and Floodplain Topography in Priority Erosion Hazard Areas (Anchor QEA, May 2021)
• Modeling climate change conditions for the Chehalis Basin Strategy (Watershed Science and Engineering, June 2021)
• Delineation of Late-Century 100-Year Floodplains for the Chehalis Basin (Watershed Science and Engineering, July 2021)

2017-2019 biennium studies

• Restorative Flood Protection Feasibility Assessment (Natural Systems Design, Jan 2020)
  • Appendix 1: Existing Conditions Summary (part 1)
  • Appendix 1: Existing Conditions Summary (part 2)
  • Appendix 2: Cost Assessment for Property and Transportation Impacts
  • Appendix 3: Hydraulic Modeling Part 1 Report
  • Appendix 3: Mapbook A – 100-year Flood Maps
  • Appendix 3: Mapbook B – Highly Engineered RFP 100-year Flood Maps
  • Appendix 3: Mapbook C – Climate Change 100-year Flood Maps
  • Appendix 3: Mapbook D – Landcover – Existing
  • Appendix 3: Mapbook E – Landcover – RFP
  • Appendix 3: Mapbook F – Landcover – HE – RFP
  • Appendix 4: Analysis of Agriculture
  • Appendix 5: Landowner Interview Project Summary
  • Appendix 6: Plant Communities
• Chehalis Basin Strategy Phase 3 Landslide Evaluation (Shannon & Wilson, May 2019)
• Chehalis River Basin Climate Change Flows and Flooding Results (Anchor QEA, May 2019)
• Chehalis-Centralia Airport Levee Wetland Delineation Report (Anchor QEA, May 2019)
• Rock Quarry Characterization Potential RCC Aggregate Sources for  Chehalis Dam (Shannon & Wilson, March 2019)
• Phase 3 Chehalis Dam Geotechnical Data Report (Shannon & Wilson, March 2019)
• Chehalis River Existing Conditions RiverFlow2D Model Development and Calibration (Watershed Science and Engineering, February 2019)
• Chehalis River Basin Hydrologic Modeling (Watershed Science and Engineering, February 2019)
• Chehalis River Smolt Production Report 2018 (Washington Department of Fish and Wildlife, January 2019)
• Wetland, Water, and Ordinary High Water Mark Delineation Report (Anchor QEA, December 2018)
• Chehalis River Off-Channel Habitat Hydrologic Monitoring Project (Anchor QEA, October 2018)
  • Appendices A-C
  • Appendices D-F

• Flood Retention Facility – Expandable (FRE) Supplemental Design Report (September 2018)
• Fish Passage: Collect, Handle, Transfer, and Release (CHTR) Preliminary Design Report (February 2018)

2015-2017 programmatic EIS supporting documentation

• Geomorphology, Sediment Transport, and Large Woody Debris Report (June 2017)
• Combined Dam and Fish Passage Design Conceptual Report (July 2017)
• Analysis of Salmonid Habitat Potential to Support the Chehalis Basin Programmatic Environmental Impact Statement (July 2017)
• Washington Department of Fish and Wildlife Studies
  • 2015 Upper Chehalis Instream Fish Study (September 2016)
  • 2015 Chehalis ASRP Off-Channel Habitat Summary Based on Egg Mass Surveys: 2nd Progress Report (November 2015)
  • 2015 Chehalis ASRP Off-Channel Habitat Summary Based on Off-Channel Extensive Surveys: 2nd Progress Report  (November 2015)
  • 2016 Chehalis ASRP Intensive Surveys in Off-Channel Habitat: 2nd Progress Report (July 2016)
  • 2016 Chehalis ASRP Instream Amphibian Surveys: 3rd Progress Report (July 2016)
  • 2015 Draft Riverscape Study Report (January 2016)
• Behavior and Movement of Adult Spring Chinook Salmon in the Chehalis River Basin (Liedtke, USGS, 2016)
• Effects of Climate Change on the Hydrology of the Chehalis River Basin (Mauger et al, July 2016)
• Chehalis Basin Strategy: Reducing Flood Damage and Enhancing Aquatic Species, Phase 1 Site Characterization, Technical Memorandum (HDR and S&W, September 2015)
• Chehalis Basin Strategy: Reducing Flood Damage and Enhancing Aquatic Species, Phase 2 Site Characterization, Technical Memorandum (July 2017)
  • Appendices A-D
  • Appendices E-I
• Chehalis Basin Strategy: Reducing Flood Damage and Enhancing Aquatic Species, Phase 2 Site Characterization, Technical Memorandum — Draft (HDR and S&W, September 2016)
• Chehalis Basin Strategy: Flood Retention Dam Summary of Costs and Life of Dam (September 2016)
• Literature Review of the Potential Changes in Aquatic and Terrestrial Systems Associated with a Seasonal Flood Retention Only Reservoir in the Upper Chehalis Basin (March 2017)
• Landslide Reconnaissance Evaluation of the Chehalis Dam Reservoir (S&W, September 2015)
• Upper Chehalis Basin Large Wood Loading Inventory (Anchor QEA, September 2016)
• Restorative Flood Protection Technical Report – Draft (NSD, September 2016)
• Development and Calibration of the Chehalis River CE-QUAL-W2 Water Quality Model (PSU, April 2017)
• Reservoir Water Quality Model (June 2017)
  • Appendix A
  • Appendix B
  • Appendix C
  • Appendix D
  • Appendix E
• Summary of Water Quality Data Collected on February 9, 2017 and March 29, 2017 (June 2017)
• Operations Plan for Flood Retention Facilities (June 2017)
• Site Characterization and Dam Conceptual Design Presentation (December 2016)
• Upper Chehalis Basin HEC-HMS Model Development (June 2017)

Land use/floodplain management studies

• Repetitive Flood Loss Strategy (French & Associates, 2014)
• Community Rating System Program Review (French & Associates, 2014)
• Chehalis River Basin Basin-Wide Floodplain Management Assessment (French & Associates, 2014)
• Floodplain Management Assessment Master Report (French & Associates, 2015)
• Status of Improved Regulatory Standards (French & Associates, 2017)

Washington Department of Fish and Wildlife species/habitat studies

• Terrestrial Amphibian Survey (2014)
• Stream-associated Amphibian Survey (4th progress report) (2017)
• Stream-associated Amphibian Survey (3rd progress report) (2016)
• Stream-associated Amphibian Survey (2nd progress report) (2015)
• Amphibian Egg Mass Off-channel Survey (2016)
• Intensive Off-channel Survey (2016)
• Waterfowl and Waterbird Abundance (2017)
• Changes in the Chehalis Floodplain: 1938-2013 (2017)
• Investigating Juvenile Life History and Maternal Run Timing of Chehalis River Spring and Fall Chinook Salmon using Otolith Chemistry (2017)
• Grays Harbor Fall Chum Abundance and Distribution, 2017 (2018)
• Movement and Home Range Study of Select Native Fishes in the Chehalis River, Washington State (2018)
• Summer Riverscape Patterns of Fish, Habitat, and Temperature in Sub Basins of the Chehalis River, 2013-2016 (2018)
• Chehalis River Smolt Production, 2018 (2019)

October 11, 2016 policy workshop presentation

• Causes of Extreme Flooding

September 21, 2016 technical workshop presentations

• Programmatic SEPA Draft EIS
• Species and Habitat Studies
  • Riverscape
  • Restoration potential monitoring
  • Salmon and steelhead spawning above the dam site
  • Summer rearing and movement for native fishes – in proposed dam footprint
  • Behavior and movement of adult Spring Chinook
  • Amphibian and non-salmonid fishes (includes occupancy modeling)
  • Waterfowl
• Climate Change
• Dam Operation Studies
  • Water quality
  • Fish passage
  • Geomorphology
  • Landslides analysis
  • Vegetation management plan
• Restorative Flood Protection Studies

September 22, 2016 technical workshop presentations

• Programmatic SEPA Draft EIS
• Flood Retention Facilities (Dam)
• Restorative Flood Protection
• Other Large- and Local-scale Flood Protection Action Elements 
• Aquatic Species Habitat Actions
• Comparison of Combined Alternatives

Reports

• Chehalis Basin Work Group Recommendations Report (2014)
• Ruckelshaus Center Alternatives Report (2012)
• Executive Summary of the Ruckelshaus Center Alternatives Report (2012)
• Comments on the Draft Ruckelshaus Center Alternatives Report (2012)

January 21, 2016 ASRP workshop

• Summary of January 21, 2016 ASRP Workshop
• Compiled Presentations from January 21, 2016 ASRP Workshop

October 7, 2015 policy workshop

• Compiled Presentations from October 7 Policy Workshop

September 22, 2015 technical workshop presentations

• Confederated Tribes Porter Restoration
• Extensive Off-channel Habitat Surveys
• Instream Amphibian Surveys
• Off-channel Habitat Egg Mass Surveys
• Off-channel Habitat Beaver Assessment
• Results from a Pilot Study to Evaluate Movement and Temperature Use Patterns of Adult Spring Chinook Salmon
• Riverscape Patterns of Fish and Habitat
• September 22 Synthesis Session
• Stream-associated Amphibian Surveys
• Summer Movements of Juvenile Salmonids
• Summer Rearing Distribution Behavior of Juvenile Salmonids: Synthesis and Next Steps
• Temperature Characteristics of the Chehalis River Watershed within the Distribution of Spring Chinook Salmon
• Upper Chehalis River Smolt Trapping, 2013-2015
• Using PHABSIM to Investigate Effects of Altered Streamflow
• Water Quality Studies Completed in 2013-2015 Biennium
• WQ Technical Tasks

Technical memos from 2013-2015 biennium

• Aquatic Species Restoration Program Effects Report – Final
• Aquatic Species Restoration Program Report – Final
• Aquatic Species Enhancement Plan Data Gaps Report
• Chehalis Basin Strategy 2015-2017 Biennium Scope and Budget – Final
• Chehalis Phase 1 Site Characterization
• Comparison of Alternatives Report – Final
• Hydraulic Model Report – Final
• Small Projects Report – Final
• Structures in Floodplain Survey Report – Final
• Water Retention and Fish Passage Report – Final
• WSDOT I-5 Chehalis Flood Report – Final