Grass Clippings and Storm Water

Grass Clippings

With heavier than normal rainfall we have received over the past year, many residents have had to mow their lawns a lot more often.  Heavy rains can carry leaves and grass clippings into our storm drain system which lead to our local creeks, streams and lakes.  All of these yard waste materials contain phosphorus which is a primary cause of water quality problems in our lakes and ponds.  Grass clippings, leaves, and brush that is not properly disposed of, can also impede the flow of storm water causing flooding in some cases. 

Grass Clippings
When mowing your yard, please make certain that you do not blow grass clippings into the street.  When mowing, make the first few passes with the lawnmower blowing the grass clippings into the lawn, and not the street.  Take care to use a broom or leaf blower to blow excess grass clippings off the street and sidewalk back into the lawn.  Do not use a hose to wash the grass or leaves into the street and down storm drains.


The U.S. EPA advises that leaving your grass clippings on the lawn doesn’t cause thatch buildup.  Grass clippings are about 90 percent water, so they decompose very quickly.    Keeping your grass clippings on the lawn and not in the street or gutter adds fertilizer to your lawn, reduces your lawn’s annual fertilizer needs, and reduces water pollution.