Pick up after pets. Pet waste contains bacteria, nitrogen, and phosphorus.
Keep grass clippings and leaves off the street and away from storm drains.
Clean up spilled fertilizer, oil, and other household chemicals. They should be disposed of properly at your local Hazardous Waste collection facility. They should not be poured down a storm drain, into the ditch, or on the ground.
Wash your vehicle on the lawn. Soaps and detergents can contain phosphorus and other nutrients which will benefit your lawn but negatively impact the quality of our nearby waters.
Maintain your vehicle to be sure there aren't any leaks.
Install a rain barrel to harvest rain for reuse on your lawn or garden.
Plant a tree or install a rain garden. Both have deep roots systems that will filter out pollutants and absorb more water than the grass in your lawn can alone.