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Mosquito control involves reducing the number of mosquitoes in an area through either mechanical or chemical methods. Although we should all work to reduce the number of mosquitoes in our area, the responsibility of mosquito control ultimately lies with the property owner (city, county, or private ownership). As a result, mosquito control measures are determined by the landowner.
  • Stormwater ponds:

    If you believe that a stormwater pond is a source of mosquitoes, look for a sign posted near the pond or call your local public utilities office to determine who is responsible. If you are not sure who owns the stormwater pond, call your city or county government for more information.

    The King County Department of Natural Resources and Parks maintains stormwater ponds in unincorporated King County. Call 206-296-1900 if you have concerns about a DNRP stormwater pond.

    See mosquito control in stormwater ponds or other drainage structures, such as catch basins, on private property (PDF).

  • County property:

    Mosquito control is done by different agencies in King County including Dept. of Transportation/Roads, Metro/Transit, Facilities Management Division, and Solid Waste Division and Wastewater Treatment Division.

  • City property:

    Each city has its own plan for dealing with mosquito problems and stagnant water. Please contact your city's Public Utilities department, found in the government section of your phone book, if you have a problem or question relating to mosquito control policies.

  • Private property:

    Public Health does not have any regulatory authority to require property owners to remove mosquito habitat except if the habitat is in violation of solid waste regulations. The responsibility of mosquito control ultimately lies with the property owner (city, county or private ownership.) For additional guidance refer to mosquito control on private property (PDF).

  • Permitted swimming pools on private property:

    If you have a concern about a public swimming pool or wading pool or a swimming pool at an apartment or condominium complex contact Environmental Health’s Food and Facilities Program at 206-263-9566.

Quick tips on how to prevent your property from becoming a mosquito breeding ground

Help your elderly or frail neighbors and relatives with these activities (older people are more vulnerable to severe West Nile virus.)

  • Tip water out of barrels, buckets and wheelbarrows and turn them over so water cannot collect
  • Tip out containers that could hold water such as toys, cans or plant saucers weekly
  • Empty children's wading pools weekly
  • Change water in birdbaths, pet watering dishes and animal troughs at least once a week
  • Discard, properly store or drill holes in used tires
  • Clean debris from ornamental ponds and keep fountains running during the summer
  • Stock ornamental ponds with fish
  • Maintain swimming pools and hot tubs
  • Recycle old bottles, buckets, and cans
  • Clean leaf-clogged gutters
  • Drain flat topped roofs
  • Dump water off of tarps and plastic sheeting
  • Drain water from covers on pools, boats and hot tubs
  • Repair leaky outdoor faucets
  • Cover rain barrels with mosquito screens
  • Cover garbage cans with an appropriate lid
  • Repair ripped window and door screens and make sure they fit tight; use a screen door on doors that often are left open
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

  • Improve drainage of livestock trampled areas and manure piles to reduce water accumulation
  • Turn over buckets, pails and feeders when not in use to prevent water accumulation
  • Drain and fill water troughs weekly or add goldfish or koi to eat mosquito larvae or use mosquito dunks
  • Fix leaky faucets around barns or stables
  • Cover and store hay away from sources of water
  • Talk to your veterinarian about immunizing horses against West Nile virus
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

  • Keep containers that cannot be discarded free of standing water
  • Remove debris, such as dead leaves and garbage from drainage ditches
  • Improve drainage in irrigation ditches to ensure water is flowing
  • Maintain a tidy operation--remove unnecessary debris and equipment that can accumulate water
  • Remove or properly store tires at the work site
  • Cover or turn over equipment that can accumulate water (tires, drums, or containers)
  • Fill or drain tire ruts and other areas that can accumulate water
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

Store tires so they do not accumulate water. This can be done by:

  • Covering tires with a tarp
  • Storing tires in a covered enclosure
  • Drilling holes in waste tires so that water drains out

Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means.

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

  • Cover or turn over equipment that can accumulate water, including drums, buckets and containers
  • Keep containers that cannot be discarded free of standing water
  • Fill in soil depressions and tire ruts that accumulate water
  • Remove or properly store tires on your site
  • Remove debris from ditches
  • Improve drainage to reduce standing water
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

  • Empty containers, tarps and equipment where standing water collects both in your boat and on the deck
  • Empty standing water on boat covers and/or from the hull of your boat
  • Pump out boat bilges to remove standing water
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.

  • Clean catch basins and lawn drains at least once a year, preferably in the spring
  • Ensure proper drainage from playground equipment where water accumulates
  • Drill holes in tire swings so that water drains out
  • Fill depressions in playing fields to prevent water from pooling
  • Clean out gutter and flat roof drains so water can flow freely away
  • Keep lawns and playing fields trimmed; they can provide resting sites for adult mosquitoes
  • Keep garbage and grass clippings out of ditches
  • Consult a licensed pest control operator for mosquito habitat that cannot be controlled by drainage or other means

NOTE: If you are considering using a pesticide to control mosquitoes, please see the legal requirements.