Storm Drain FAQ

What is storm water?

Storm water is rainfall or snowmelt that flows across our yards, streets, buildings, and parking lots, where it picks up a variety of pollutants and then enters our waterways directly or through the storm drain system.

What is a storm drain?

In your street you can see grates covering holes in the road which are usually close to curbs.  The grates allow water to flow off your street when it rains or storms and into drains which take the water to our rivers and Lake Michigan.  The storm drains prevent your street and yard from flooding. 

What flows into a storm drain?

Rain or storm water should be the only substance flowing into the storm drains.  Unfortunately, storm water carries with it chemicals from your lawn and garden, pet waste, trash, car wash water, motor oil, antifreeze, salt from snow removal, grass and yard waste, household hazardous waste and anything else left on the ground or street.  Some people may discard waste in storm drains thinking the wastes will be treated but the system is not equipped to handle toxic substances.   

What happens to everything that flows down the storm drains?

Polluted storm water flows eventually into rivers and lakes, such as Lake Michigan, from which Milwaukee draws drinking water. 

Why is it a problem if pollutants flow into Lake Michigan with the storm water?

It is a problem because the pollutants:

-         can make humans and aquatic life sick (humans can get sick from eating contaminated fish, drinking polluted water, or swimming in contaminated water)

-         can kill plant and aquatic life

-         increase sediment thereby decreasing living space for aquatic life; sediment covers fish eggs and makes it hard for fish to find food; sediment also slows the river flow and makes it less attractive; sediment makes rivers shallower and therefore warmer, which chases cold water fish away; sediment prevents the sun from getting to the plants in the water so no photosynthesis occurs, reducing the plants available for wildlife to eat, sediment decreases aesthetic beauty and can fill waterways used for boating

-         increase the algae and other unwanted plant life that make it harder for fish to move around and find food and for wanted plant life to grow; increased algae makes swimming and boating difficult and unpleasant

-         increase the algae and wastes which are broken down by bacteria, thus reducing oxygen levels in the water and killing fish and other aquatic life.