A lot of stormwater runoff is created from public areas like roads and parking lots because they are impervious surfaces. Additional stormwater runoff is created from roof drains/gutters, and driveways from households and businesses. These sources also have the potential to move pollutants including sediment, salt, and organic material (grass clippings, leaves) into streets and storm drains, creating water quality concerns in the downstream surface waters. Here are some easy ways that homeowners and businesses/organizations can reduce stormwater runoff and improve runoff water quality:
Use deicing chemicals sparingly
The Minnesota Pollution Control Agency's (MPCA) Road Salt and Water Quality website features numerous tips for winter sidewalk and parking lot maintenance. Information on this website is geared toward individual homeowners, road authorities and organizations that manage sidewalks and parking lots.
A 15-minute video demonstrating how to clear ice and snow from steps, ramps, curb cuts, entryways, and other small sites without excessive use of deicing chemicals is available under the “Education/Resources” tab. The video was created by the Mississippi Watershed Management Organization, University of Minnesota Landcare, Digital Motion, Fortin Consulting, and the Minnesota Pollution Control Agency as part of a comprehensive training effort to reduce the impacts of road salt and deicing chemicals on the environment.
Water the lawn, not the pavement
If you use a sprinkler to water your lawn or garden, make sure you are not watering the driveway, sidewalk, or road. For gardens, try soaker hoses to get the water right to your plants and limit splashing.
Keep your grass longer
The roots of grass are generally as long as the height of the lawn. That means the taller your grass is, the better it can absorb water and the greener it will be. It will require less water and fertilizer and make it harder for weeds to germinate. Set your lawn mower cut height to 2.5 to 3.5 inches.
Don’t over water
Grass can only absorb about 1 inch of water at a time. Try this trick: place an empty tuna can in your lawn and turn on the sprinkler. When the can is full, the grass has had enough water. When all of the water in the can evaporates, it is time to water again. You might not have to water as often as you think.
Keep in mind that your city may have watering restrictions that do not allow for watering every day. If a soaking rain occurs, consider turning off the timer setting of a sprinkler system, so you’re not watering during or immediately after a storm that has saturated the lawn. Or, purchase a wireless rain sensor from a home improvement store that can tell your system to automatically shut off after a rain event.
Plant deep-rooted native plants or trees
Native flowers and grasses can have root systems 4-12 feet deep. These deep roots anchor the plants and keep soil from washing away. They also increase the amount of water the soil can absorb. Select your favorite native plants at a Landscaping for Clean Water program session.
Buffer your shoreline
A shoreline with trees and native plants will hold the soil steady when it rains. Buffers also catch and filter many of the pollutants found in melting snow and stormwater runoff. Find more information about shoreline improvement through native planting through the Landscaping for Clean Water program.
Scoop the poop
Pet waste may not seem like a big issue, but the cumulative effect of not picking up pet waste can contribute to higher levels of pathogens in water bodies. Waste should be removed and disposed of in the trash every time, but it is especially important if you take your pup through parks and other areas adjacent to water bodies and storm sewers.
Wash your car responsibly
Commercial car wash facilities often recycle their water or are required to send their wash water to the wastewater treatment plant, so if at all possible, use a facility to keep your car clean.
If you wash your own car, use soap labeled “non-toxic,” “phosphate free,” or “biodegradable.” The safest products are vegetable-based or citrus-based. You should also stay away from acid-based wheel cleaners and engine degreasers. Wash your car on grass, gravel or a location where the water can be diverted to nearby landscaping. This allows the water to soak into the ground and not run into storm drains.
Sweep up grass clippings on paved areas
Grass clippings are a source of phosphorus, the nutrient that turns lakes and rivers green with algae. Sweep up grass clippings that end up on streets, sidewalks, and driveways, so they don’t end up in the nearest water body. Keeping grass clippings on your lawn adds nutrients and shades the soil to retain moisture. You can reduce fertilizer use by one-third to one-half when you leave clippings. Collected clippings can also make a great addition to an active compost pile or container.
Soften your soil
The soil beneath most residential lawns is highly compacted and absorbs little water. You can reduce soil compaction and improve infiltration in your lawn by renting a lawn aerator from a local garden supply store.
Test the soil
Minnesota soils are naturally high in phosphorus, so lawns usually don't need any extra. But to determine if your lawn is nutrient poor and requires fertilizer, have a soil test completed by the University of Minnesota soil testing laboratory.
Use zero phosphorus fertilizer
Protect water quality by using fertilizers that don’t contain phosphorus—it’s the law in Minnesota. Fertilizer packages have a number for nitrogen, phosphorus, and potassium (N-P-K) content. Look on the label for a middle number of zero to ensure that it is phosphorus-free. Fertilizer in stormwater runoff heads to surface waters and contributes to algae blooms. Too much algae lowers oxygen levels and darkens the water, which has devastating effects on fish populations. A common cause of lake and river pollution is phosphorus runoff. If you have leftover fertilizer, take it to The Recycling Zone.
Build or buy a rain barrel
Rain barrels collect roof runoff. Water collected in a rain barrel would often flow through the downspout, onto a paved surface, into a storm drain, and into a nearby surface water. Instead, rain barrels conserve water that can be used to water lawns and gardens. Find out more.