Did you know?

Clean water in our lakes, reservoirs and streams starts at home with basic practices YOU can incorporate into your lawn care program. Click the drop down sections below to learn more about lawn care, water quality, and what you can do to help to preserve, protect, and restore our lakes.

Water Quality Begins at Home

Regardless of where you live, you are part of a watershed – a region where water flows across of under the ground on its way to a lake, river, stream, reservoir or ocean. Year-round lawn and yard care practices impact water quality even if you don’t live near a water body.


Thanks to sound science, we now understand how phosphorus-containing lawn fertilizers contribute to poor water quality. Phosphorus, the middle number on the lawn fertilizer bag, is present in all living things – including soil. However, too much phosphorus disrupts nature’s balance. how and why does this imbalance occur?

There's a Pipeline From Your Lawn to a Water Body

Runoff from unused phosphorus in lawn fertilizer moves across lawns, roads and woods into streams and ditches, and eventually into reservoirs and lakes. The majority of Indiana soils already contain adequate amounts of phosphorus for a healthy lawn, so most lawns don’t need the extra food.

Phosphorus is “junk food” for algae present in a reservoir, lake or stream. One pound of phosphorus can produce 10,000 pounds of wet weeds and algae. As you can see from the photo, when phosphorus is washed into the lakes, the algae grows out of control (known as repeated algae bloom), reducing clarity and visibility. Some forms of blue-green algae can be toxic.

Repeated algae blooms create “green” lakes, which can:

■  Cause fish kills or loss of cold water fish habitat;

■  Add a foul taste and smell to the drinking water;

■  Become a neighborhood nuisance; and

■  Produce poor water quality for fish, wildlife and humans.

The Economic Impact

As watersheds are converted from their natural state to residential, commercial or industrial uses, the amount of phosphorus runoff into a lake can increase five to ten times. Green lakes impact a community in several ways. Poor water quality significantly reduces recreational use of the water body. It also reduces property values.


Is There a solution?

The solution to phosphorus runoff is to control the source. Using phosphorus-free lawn fertilizer is one easy way anyone can contribute to better water quality – regardless of where you live. When shopping for lawn fertilizer, look for the three numbers on the lawn fertilizer bag (photo above). The middle number indicates the phosphorus content of the fertilizer, so look for a zero. The other numbers indicate the amount of nitrogen (first number) and potassium (third number) in the fertilizer. Phosphorus is needed only on newly seeded lawns or where soil testing indicates a deficiency.

What You Can Do!

■  Have your soil tested. For information visit Purdue Cooperative Extension Service’s Web Site at www.agry.purdue.edu/turf/pubs/ay18.htm or call your county Extension office (listed at www.ces.purdue.edu/counties.htm and in the county government section of the phone book).

■  Use phosphorus-free lawn fertilizer! Your local nursery or landscape supply store should have phosphorus-free fertilizers in stock. In not, ask the manager to order it.

■  Apply fertilizer only when it is needed, during the right season, and in proper amounts.

■  Avoid getting fertilizer on driveways, sidewalks and storm drains. Above all, fertilize carefully. Don’t let your fertilizer application get into lakes, streams or ponds.

■  Use a mulching mower and cut no more than the top third of the grass.

■  Clean up after your pet. Pet waste contains phosphorus.

■  Prevent soil erosion by covering the ground with vegetation or mulch.

■  Keep leaves, grass clippings and soil out of streets and gutters. Compost leaves and clippings on site, bag them for collection or use a community compost program. Registered organic recycling and composting facilities are listed at www.IN.gov/idem/oppta/recycling/organics/programs/compostfacility.html.

Grass Clippings

Grass Clippings

Shoreline Planting

Shoreline Planting

For More Information

Indiana Department of Environmental Management
Office of Water Quality

Watershed Planning Branch

(317) 233-8488

(800) 451-6027/(toll-free in Indiana)


The goal of the Watershed Planning Branch of IDEM’s Office of Water Quality is to achieve improvements in Indiana’s surface water quality. The branch uses several tools to achieve this goal – total maximum daily load calculations, watershed management grants, technical assistance and education.


Indiana Association of Soil and Water Conservation Districts

(317) 692-7325


The mission of the Indiana Association of Soil and Water Conservation Districts is to represent soil and water conservation districts as one voice, and to assist the leadership of local SWCDs through coordination and education for the wise use and management of our natural resources.