Freshwater Habitat

Indicator

King County's Freshwater Habitat Index is derived from three main groupings of results describing the conditions of rivers and streams, groundwater and lakes. Wetland conditions do not factor into the index at this time because of inadequate data. Our weighting system applies 45 percent each to rivers and streams and to lakes, and 10 percent to groundwater condition results toward the overall freshwater habitat quality. The weighting of groundwater quality would be larger if data existed for groundwater nitrates and well water levels for other areas besides Vashon-Maury Islands.

Status

Overall below standard, though with some areas (lakes) of lesser concern

Influencing factors

The impacts of development, landowner practices in areas close to the shoreline and pollutants are the dominant drivers determining the health of freshwater bodies in King County. Less forest cover and increases in impervious surfaces result in higher stream temperatures and more urban runoff. 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.

Existing DNRP response

King County is working to replace old, underground, open wastewater pipes with closed systems to reduce wastewater overflows during heavy rains. Additionally, new combined sewer storage tunnels have been built to hold millions of gallons of combined wastewater and stormwater during heavy rain events. Once the storm has passed, the combined wastewater and stormwater can be sent to a wastewater treatment facility for processing. Other programs, such as King County's agriculture and forestry programs work to reduce the impacts of farming and timber harvesting on our creeks and streams.

Priority new actions

King County has established a new countywide Flood Control Zone District to better manage levees and revetments along major rivers, and cooperative watershed management efforts will be part of this initiative. This is the second year that revised critical area and clearing and grading regulations are in place. The regulations aim to offer greater protection to all critical areas including, creeks and streams. Additionally, King County is updating its Shoreline Master Program. Included in this state-mandated update of its shoreline management is an in-depth analysis of the condition of all shorelines within the county, including most creeks, streams and lakes.

What you can do

Properly dispose of unused pharmaceuticals, harmful chemicals and 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.

More information about King County's Lakes, Rivers/Streams, and Groundwater is available by continuing to the pages for these measures:

• Lakes
• Rivers/Streams
• Groundwater

Back to top