Best management practices for lakes

Washington State Department of Ecology

Ecology home > Water Quality > Aquatic Plants, Algae, and Lakes > Best Management Practices for Lakes

There are many actions communities and homeowners can take to protect their lakes. Best management practices for lake residents include:

Maintaining septic systems.
Managing waterfowl.
Developing good landscape practices.
Controlling run off and soil erosion.
Reducing or eliminating fertilizer use.
Properly disposing of pet wastes.
Washing vehicles away from the lake.
Reducing or eliminating pesticides.

Links to more information about best management practices.

Maintaining septic systems

Improperly maintained on-site sewage disposal systems may contribute nutrients and potentially bacteria to the lake. The following practices will reduce contamination from septic systems.

Have your septic tank checked every other year and pumped when necessary.
Wash full loads of clothes and use water-saving showers and toilets to avoid stressing your septic system.
Do not use a garbage disposal.
Do not use septic system additives.
Keep solvents, plastics, paper diapers, and other similar products out of your septic system.
Do not pave over or park on your drain field. The soil needs to breathe.

For further information about septic systems and their maintenance see the EPA website http://www.epa.gov/owm/septic/pubs/homeowner_guide_long.pdf

Everyone enjoys feeding ducks and geese, but feeding these birds encourages them to take up residence on your lake. Ducks and geese bring poop and associated nutrients and bacteria. Scientists estimate that up to half of the nutrient load to Green Lake in Seattle was caused by resident waterfowl. Things that you can do to discourage waterfowl include:

Not feeding or encouraging others to feed waterfowl.
Using good landscaping practices to discourage waterfowl. Ever notice how those lake lots with grass growing down to the water's edge always attract geese, while lots with more natural landscaping don't seem to have a problem? Waterfowl, particularly Canada geese, feed on and are attracted to lawns. If you have a lawn, site it away from the water's edge and plant low-growing bushes near the water's edge. Geese avoid walking through shrubbery because it may conceal predators.

Learn more about Canada geese at the United States Department of Agriculture website

Landscape practices

Plan and maintain lawns and gardens adjacent to lakes to prevent contamination of surface and ground water. Consider native vegetation as a quality alternative to lawns and landscapes. Native vegetation provides a more diverse and balanced plant community and habitat. Contact a nursery that supplies native plants for species best adapted for your needs. If you have a lawn, use a mulching lawnmower. This can reduce fertilizer use by about 25 percent.

Don't site your compost bin right next to the lake shoreline. Compost contains nutrients that can leach into lake waters if located near the shoreline. A balanced approach to waterfront landscaping retains some natural habitat and reduces pollution and erosion while also meeting your aesthetic and access needs. See also Blueprint for a Lake-friendly Landscape.

Controlling runoff and soil erosion

Shoreline Management Regulations prohibit intensive removal of vegetation near the shore or on steep slopes. Check with your local jurisdiction for specific regulations.

Take steps to offset problems which could occur under the following conditions:

Areas of exposed soil or poorly established vegetation.
Coarse textured soils such as sands or sandy loams.
Property sloping toward water.
Impervious surface such as sidewalks and driveways.

Fertilizer use

Avoid the use of chemical fertilizers if possible. Native vegetation requires less fertilizer. Use compost or manure rather than chemical fertilizers; however, compost and manure can also degrade water quality if used in excessive amounts. If you must use fertilizers, use natural time-release products.

If you apply fertilizers to lawns and gardens, adhere to the following guidelines:

Have your soil tested to determine how much fertilizer to apply.
Water your lawn after fertilizing, but do not allow excess water to run off into surface waters.
Sweep up any fertilizer which is spilled on hard surfaces such as walks and driveways.
Do not spread fertilizer within 75 feet of surface waters or wetlands.
Use a "drop" spreader and not a "cyclone" spreader to reduce the chances of getting fertilizer in the water.

Pet waste disposal

Regularly scoop up and dispose of pet wastes in your yard. Bury or bag pet wastes and dispose of the bags in the garbage. Do not compost pet wastes because they may contain harmful diseases or bacteria as well as the plant nutrients, nitrogen and phosphorus. Do not dispose ever of pet wastes in the lake.

Car washing

Wash your car at a licensed car wash. If you wash your car at home, wash it in your yard so that the soap and grime will not go into the storm drains directly into your lake.

Reducing or eliminating pesticide use

Avoid the use of chemical pesticides if possible. Consult a professional from the Washington State University Cooperative Extension Service to determine alternative methods for pest controls.
The following practices will minimize the potential of contamination from pesticides:

Properly identify the cause of the problem (insect, disease, or other factor).
Determine whether there is an economic justification to initiate control of the pest.
Consider controlling the pest without a pesticide.
Use the least toxic and most readily degradable pesticide.
Read and follow the pesticide label carefully. Pay special attention to warnings about use near water and safety precautions.
Do not apply pesticides when it is windy to avoid the possibility of drift.
Purchase only the amount of pesticide needed to control the problem each season.
Dispose of waste pesticides properly. Do not pour them on the ground or into storm drains, surface waters, or sanitary treatment systems. Consult with your local solid waste office for proper disposal methods.

Links to more information about best management practices

Click here to see the King County Lake Stewardship Program's lake-friendly fact sheets

Shoreline Best Management Practices

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