Please join us and learn how King County is working on a project that will improve habitat and reduce flood and erosion risks in and along the lower Miller River. King County plans to remove approximately 1,000 feet of the closed portion of NE Old Cascade Highway west of the washout and 500 feet of the Miller River Curve Levee. Questions about the NE Old Cascade Highway are addressed in our FAQ section. King County is also coordinating with Burlington Northern Santa Fe Railway (BNSF) to manage existing risks to vulnerable segments of the railroad.

Key terms:

• • Alternatives: Different project design options to achieve the project purpose, need, and objectives.
  • Channel migration zone: The area along a river or stream where the channel is likely to move over time.
  • Cubic feet per second (cfs): The amount of water moving in a river or stream representing a volume of one cubic foot passing a given point in one second.
  • Culvert: a tunnel-like structure, usually a pipe or concrete box, that allows water to flow under a road, railroad, or similar obstruction.
  • Fish habitat: The aquatic environment and adjacent upland area critical for fish to live, breed, and grow during various life stages.
  • Floodplain: The relatively flat lands adjacent to a river, formed mainly of river sediments, that become inundated during periods of high flow or floods.
  • Floodplain reconnection: Reconnecting rivers to their floodplain by removing structures such as levees, improving the natural function and ecology of rivers.
  • Large wood structures: Engineered structures constructed in rivers and floodplains to simulate naturally occurring log jams. Log jams help direct river flow and create forage and refuge habitat for salmon.
  • Levee: A raised structure made of earth intended to contain, control, or divert the flow of water to provide protection from flooding.
  • One percent annual chance flood: A flood that has a one percent chance of occurring or being exceeded in any given year. This is also known as the 100-year flood.
  • Revetment: a sloped, protective facing of rock placed on riverbanks or embankments to prevent erosion.
  • Riparian area: area along the river bank between a water body and upland, critical habitat that protects water quality and riverbank integrity.
  • Side channel: A smaller channel that runs parallel to the main channel of a river. These areas often provide important rearing habitat for young salmon.
  • Trap-and-haul: a fisheries management technique used to move fish—most commonly migratory salmon and steelhead—around impassable barriers like dams or waterfalls.