Grass clippings that land on driveways, sidewalks, and roads often are washed into storm drains and end up in local lakes and streams adding excessive nutrients like phosphorous and nitrogen which can lead to greater production of algae and aquatic weeds and poorer water quality. Grass clippings are also a hazard for bikers. When mowing, please mow in directions that result in the grass clippings staying on the lawn instead of driveways, sidewalks, trails, and roads.

This practice is also a requirement of City Ordinance 135.03: It is unlawful for any person to throw or deposit on any street or alley any glass, glass bottle, nails, tacks, wire, cans, trash, garbage, rubbish, litter, offal, leaves, grass or any other debris likely to be washed into the storm sewer and clog the storm sewer, or any substance likely to injure any person, animal, or vehicle.