Environmental Notes

New Year's Resolutions to Improve Water Quality

How about making resolutions for 2204 that will help improve the water quality of our city's lakes, rivers and streams? Here are a few suggestions to get you started.

  • Get to know your soil Healthy lawns benefit urban water quality by soaking up rainwater and decreasing the amount of storm water runoff into lakes and rivers. Only 10 percent of the rain falling on lawns, green space and trees results in runoff. However, 90 percent of the rain falling on streets, driveways, roofs and other hard surfaces results in runoff.

    Having healthy soil is the one thing that will have the greatest overall impact on developing a thriving lawn and garden. Take a soil test to determine what kind of soil you have and what amendments you may need to improve your soil.

    Soil tests are available for a small fee through the University of Minnesota Extension Service. The Hennepin County Extension Office can be contacted at


    Improving the soil can often be accomplished by adding organic matter such as compost. Core aeration of your lawn in the fall will also help improve your soil, particularly if it is compacted from heavy use. Aeration helps water reach the roots of the grass plant and minimize water runoff.

  • Mulch and compost Try to "recycle" your leaves and grass clippings by composting them or using them as mulch. Organic mulches such as partially decomposed compost, shredded leaves or grass clippings improve your soil structure by adding organic matter to the soil as they decompose.

    Using organic mulches on gardens, trees and shrubs reduces weed growth, conserves soil moisture and moderates soil temperature.

  • Use a zero-phosphorus lawn fertilizer Phosphorus is a food source for all plants including algae, small green plants that live in lakes and streams. Increased levels of phosphorus leads to increased algae growth. Large amounts of algae in lakes are called "blooms" or "scums."

    Too much algae is harmful to a lake, blocking sunlight and preventing other aquatic plants from growing. As algae dies and decays, it takes away much-needed oxygen from fish.

    To reduce phosphorus pollution of our lakes, creeks and rivers, Minneapolis law restricts the sale and use of phosphorus-containing lawn fertilizers. The ordinance concerns only lawn fertilizer and does not regulate the phosphorus level in fertilizers for flower and vegetable gardens.

    Of the three nutrients in turf fertilizers -- nitrogen, phosphorus and potassium -- grass needs phosphorus the least. Metro-area soils are already high in phosphorus. And nitrogen, the nutrient that makes lawns green may not be needed if grass clippings are left on the lawn, as grass clippings are a nitrogen source.

  • Redirect water runoff Runoff washes grass clippings, leaves, fertilizer and other pollutants off hard surfaces such as sidewalks and driveways and carries them into our storm sewer system. To reduce runoff, have your downspouts directed onto your lawn and not towards hard surfaces like sidewalks and driveways.

    Washing your vehicle in your driveway or on the street contributes to runoff. Soap and petroleum products washed off your car flow directly into the storm sewer system. Water flowing through storm sewers, is not treated before it enters our city lakes and streams. However, water from carwashes goes into the sanitary sewer system and is treated at wastewater treatment plants.

  • Adopt a storm drain near you! Have you ever parked on a city street in October, stepped out of your car and landed ankle-deep in leaf mush that's accumulated in the street? In the fall, as you are cleaning the gutters on your house, think of those gutters in the street.

    Although city ordinance prohibits raking leaves into the street, it is still a common practice throughout Minneapolis. Raking up leaves from the street and keeping the catch basins at the curb free of debris year-round helps to reduce pollutants and litter from being washed into our lakes.

    Marcia Holmberg is the Environmental Projects Coordinator of the Minneapolis Park and Recreation Board, www.minneapolisparks.org.