Stream-Friendly Solutions

Choosing natural home and yard care methods is easy, affordable and better for our streams, wetlands and rivers. They cost less and are less work, too! As water runs downhill, it picks up pollutants such as oil, grease, pesticides, fertilizers, and pet waste. These can wash into waterways and impact area water quality. For natural home and yard care treatments that protect our neighborhood streams, read the sections below.

Explore how you can protect our streams when you Cut the Chemicals and Do the Doody. Property owners within our service area may also receive free native plants as part of our Streamside Stewardship Program. Learn more with Stream Care Guide (PDF, 2.7MB) and Stream-Friendly Home & Yard Care (PDF, 2.6MB) or explore Metro's Yard & Garden page to help you create the yard you want.


Roof Treatments

Problem: Chemicals that kill roof moss and lichen typically contain copper, zinc and iron sulfate metals that eventually wash into water.

Solution: Use alternatives to chemical treatment to help protect our water.

  • Prevention:
    1. Keep debris and leaves off the roof. They hold moisture, promoting fungal growth and damage.
    2. Non-organic roofing materials resist moss growth.
  • If treatment is needed:
    1. Use products that are less-toxic and designed to protect the environment.
    2. Use minimal concentrations as recommended on the product label.
    3. Disconnect downspouts from gutters when applying liquid treatments. The runoff will filter through the soil and break down, instead of going to the nearest stream.
    4. Treat roofs only in dry weather to allow treatment to soak into the roof.
    5. Before you hire a roof treatment professional, ask what they use and how they handle runoff.
    6. After treatment, monitor the runoff. Reconnect downspouts after at least three rainfalls, or when there is no visible chemical residue or sheen.
  • For more information, please download our Safe Roof Moss Control Fact Sheet (PDF, 2MB)
Pressure Washing

Problem: Pressure washing your home, deck, sidewalk, driveway and vehicles can wash pollutants into storm drains and ditches that lead to waterways.

Solution: Make your cleaning activities more stream friendly by using the following tips.

  1. Sweep sidewalks and driveways, and put the sweepings in the garbage to keep pollutants and litter out of waterways.
  2. Use automatic car washes that recycle the water and properly dispose of detergents.
  3. If you must use a cleaner for pressure washing, try this less toxic recipe:
    • 2 cups mild laundry detergent
    • 1/2 cup vinegar
    • 1/4 cup lemon juice
  4. Water pressure alone often removes the dirt and grime.
  5. Before you pressure wash, figure out how to keep paint flakes, grease, and other pollutants from washing into storm drains, ditches or waterways.
  6. Collect and properly dispose of these pollutants, especially outdoor paint which might contain lead that is poisonous to plants, animals and children.
  7. If you wash your car at home, park it on grass to allow pollutants to filter through the soil.
  8. If you pressure wash, direct the spray toward grassy or planted areas
Making Mulch

Problem: When yard debris washes into streams and wetlands, the excess decaying material can reduce the dissolved oxygen needed by aquatic life. Leaves and yard debris can also clog drainage and cause flooding.

Solution: Make your own mulch pile out of yard debris and kitchen scraps. All you need is a few minutes a week and three square feet of yard. Use the following tips to turn a mountain into a molehill.

  1. Composting receptacles or "machines" are easy to use and maintain. They contain odors and speed up the decomposition process. For a list of vendors, call Metro at 503.234.3000.
  2. Keep your pile on level ground to hold materials in place and keep out animal scavengers.
  3. Keep fresh mulch away from creeks or wetlands to prevent nutrients and bacteria from leaching into the water.
  4. For quick mulching with minimal odor, start with a mixture of browns (dried up plant material) and greens (kitchen scraps and grass).
  5. A good starting recipe includes:
    • 3 parts dry leaves (Browns)
    • 2 parts fresh garden weeds and grass clippings
    • 1 part food scraps (Greens)
    • 2 parts water (or beer) added periodically
  6. Never put meat scraps or bones in pile. (They produce odors and attract scavengers.)
  7. Store kitchen scraps in the freezer to prevent odors and save trips to the compost pile.
  8. Add eggshells, paper, coffee grounds and filters to enrich your mulch.
  9. Put all yard debris in the pile.
  10. Break up large materials for faster decomposition.
Lawn and Garden Care

Problem: Herbicides, pesticides, and chemical fertilizers leach into our waterways and change water chemistry. They add nutrients that cause algae growth and harm stream life from plants to insects, amphibians, birds, fish and mammals. People don’t like the look and odor of polluted water, either!

Solution: Use non-toxic recipes and methods to help reduce excess chemicals and nutrients in our local streams, wetlands, and rivers.

General tips:

  1. Plant natives. Use native plants, trees and shrubs in your yard. They’ve adapted to the area and need less water and maintenance. You can use a Native Plant Finder to help you find plants that are right for you! Decorative native plants available in local garden centers include:
    • Shrubs
    • Snowberry (Symphoricarpos albus, S. mollis)
    • Red Huckleberry (Vaccinium parvifolium)
    • Oregon Grape (Mahonia nervosa)
    • Sword Fern (Polystichum munitum)
    • Wildflowers
    • Columbine (Aquilegia formosa)
    • Aster (Aster chilensis ssp. Hallii, A. subspicatus)
    • Lupine (Lupinus latifolius, L. polyphyllus
  2. Pull weeds. Pull weeds when they first appear to keep them from spreading. This saves time and energy, and reduces the use of chemicals. If you need to use herbicides, learn about how we use them with our Herbicide Fact Sheet (PDF, 3MB).
  3. Watch Soil pH. Use a simple test kit to check the pH of your soil. Ideal pH reduces the need to fertilize and helps plants absorb the nutrients they need.
  4. Water just enough. Water about one inch per week for a healthy lawn. Over watering your lawn encourages shallow root growth, promotes weeds and washes essential nutrients from the soil. The best time to water is early morning.
  5. Park that gas mower. A gas-powered lawn mower can pollute as much as a car. Modern push mowers are less expensive to own, operate, and maintain. They’re much better for the environment, and provide good exercise. Or, use plants and grasses that need less mowing.

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