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2017 Rating Red
2016 Rating Red

Indicator Key

In simplest terms, indicators are measures of environmental conditions, while performance measures show how DNRP is doing at improving these conditions.


King County's Aquatic Environment Index includes information about the conditions of water quality, aquatic biota, shorelines, water quantity, and sediment quality. Our weighting system for overall aquatic environment condition includes:

  • 45 percent water quality
  • 25 percent aquatic biota
  • 10 percent water quantity
  • 10 percent shorelines, and
  • 10 percent sediment quality


Overall, conditions are below standard, with a few areas of lesser concern.

Influencing factors

Over the past two centuries, increased population and development have substantially altered King County's landscape. Less forests and natural land cover increase the need for engineered stormwater controls and reduce the amount of habitat for animal and plant species. Development and deteriorating water quality impact wildlife habitat — particularly the amounts of hard or paved surfaces, loss of tree cover and other changes to natural environments. Phosphorus from blended stormwater and wastewater that bypasses the treatment process during significant storm events, failing septic systems, pet wastes and water bird droppings reduce dissolved oxygen levels and increase water temperatures. Marine habitat quality is reduced by non-point source pollution, contaminated sediments and the high percentage of shoreline that has been armored with bulkheads and other structures.

What you can do

  • Reduce your driving and reliance on cars — drippings and exhaust from vehicles and run-off from roads and parking lots are primary contributors of water quality declines.
  • Properly dispose of harmful chemicals, including unused pharmaceuticals and latex paints, instead of pouring them down the drain or allowing them to run off on the ground.
  • Minimize the use of fertilizers and pesticides by practicing natural yard care.
  • Wash your car on the grass or gravel instead of on the street or driveway, or take it to a car wash.
  • Properly dispose of or manage pet and livestock wastes.
  • Consider alternatives to bulkheads and other artificial barriers to marine shorelines.
  • Plant trees and reduce impervious surfaces by using pervious pavers in drive and walkways.
  • Encourage your local city or town to make tree protection regulations stronger.
  • Contact your elected officials and express how important wildlife protections are to you—including salmon restoration.

More information about King County's Freshwater and Marine Water Quality is available by continuing below for these measures: