Des Moines Creek Basin Committee: Options for moving forward

• Finish design and construction of capital facilities and share costs for projects that address surface water and fish habitat issues within the Basin, including:
  • Regional Detention Facility
  • By-pass Pipeline
  • Flow Augmentation Facility (eliminated from plan in 2007)
  • Habitat Enhancement and Restoration Projects
  • Operation, Maintenance, and Replacement of Basin Plan projects (listed above)

• King County, Port of Seattle, WSDOT, SeaTac, Des Moines (1996)
• Port of Seattle, SeaTac, Des Moines, WSDOT (2007)

• Committee members manage projects through jurisdictional administration.
• SeaTac takes manages budgetary resources.
• Decisions are met by consensus.

Construction and maintenance of Regional Detention Facility and Bypass Pipe

• Improved hydraulic conditions in Des Moines Creek
• Less flooding downstream
• Alternative minimum flow control standard for developers (cost savings)
• In-stream habitat improvements

• King County 2012- implemented by the Des Moines Creek Basin Committee. Designed to answer the following:
  • Temperatures and dissolved oxygen to support aquatic life
  • Have improvements in flow regime improved habitat and water quality
  • Have basin improvements improved benthic index of biotic integrity (B-IBI)
  • Are improvements improving spawning conditions for coho

• Habitat inspections (Phase I, II and III & Erosion Repair Sites)
  • King County 2015 (Habitat Inspection)
  • King County 2014 (Erosion Repair)
  • Parametrix 2022 (Year 3 Monitoring Report)
• Geomorphologic Studies
  • Fluvial geomorphic analysis of bed movement in Des Moines Creek (Marit Larson and Derek Booth, UW, 1999)
  • Confluence 2015
• Fish Barrier Assessment (S 200th Street)
  • Parametrix 2022

• King County 2012 Pre-spawn Mortality Survey

• Fish Use (annual)
  • Port electrofishing data

• Maintenance and repair of existing assets
  • Projects installed by committee, or if the project is a benefit to the entire basin
• New in-stream restoration projects
  • Bank stabilization
  • Debris removal and stream restoration
  • If benefit/need can be shown
• Public education and outreach
  • Trail signs
  • Educational mailers
  • Stewardship opportunities

• Monitoring to understand more about conditions (water quality, B-IBI, fish studies, etc.)
  • Need to know what the question is and how monitoring will inform the answer
• Capital projects to improve fish passability
  • Depends on if habitat availability warrants it
  • Need to prove benefit for all
• Upland or riparian vegetation projects (invasive species removal, tree planting, etc.)
  • Geographically fair (throughout basin)
  • Secondary to in-stream
  • Wouldn’t likely be done without committee
• Regional water quality treatment
  • Need specific projects (scope and scale, issue solved)
  • Potential retrofit of existing facilities

• On-going maintenance
  • On-going asset maintenance funding ($150k/year)
• Mechanism to replace assets
  • On-going asset replacement funding ($180k/year)

• Able to have big-picture view of watershed processes
• Cooperative decision-making can result in better projects

• Geographic boundaries (floodplain only, or upland work as well)
• Decision-making (consensus?)
• Who is responsible for what

• How is this determined?
  • Number of projects in each jurisdiction
  • Amount of funding spent in each jurisdiction
  • Ecological benefit apportioned by jurisdictional boundary

• Short list of committee funded projects, plus flexibility to add new ones
• Framework for introducing projects
• Baseline criteria
• Funding sources
• Project management (rotating or who has the most geographic area where project is located?)

• Include additional projects/strategies?
• Expand geographic reach? Within watershed but outside floodplain?
• Project management coordination/rotation

• Conceptual projects agreed upon in advance of ILA (scope, scale, cost identified)
• Flexibility for types of projects that can be considered at a later date
  • What types of projects?
  • Criteria for consideration
  • Decision-making and prioritization for advancing committee-funded projects

• Public Engagement
  • Des Moines Creek Outreach Website/portal
  • Updated/modern signs/kiosks (QR codes) about committee projects
  • Inserts included in City mailings
  • Stewardship events (remove invasive species, other events)
• Continue Habitat Monitoring
• Remove old debris deposits and conduct stream restoration in same area (Des Moines)
• One or two additional in-stream restoration projects (LWD installation) to add additional pools and more diversity (and potentially bank stabilization)
• Contribute to Des Moines estuary enhancement project?
• Contribute to 200th S. Culvert replacement?
• Placeholder funding for monitoring (to be determined)