What is Stormwater?

Stormwater is the water that originated from rain. Stormwater that does not soak into the ground becomes surface runoff. Surface runoff flows into surface waterways or storm drains which eventually discharge into surface waters.

Stormwater Pollution

As stormwater flows over the land, it can pick up pollutants such as debris, chemicals, dirt and any other pollutants it encounters. This water then flows into a storm drain, wetland, lake, river, stream or coastal water. All water that enters a storm drain is untreated and then drains into our waters. This is the same water we use for swimming, fishing and drinking.

The effects of pollution


  • Sediment: Excessive sediment or soil can cause the storm drains to clog which can lead to flooding. When sediment is deposited in lakes and streams, it can negatively affect the water quality and aquatic habitat.
  • Excess nutrients: Often called nutrient pollution, it refers to pollution caused by excessive input of nutrients. The extra nutrients, usually phosphorus or nitrogen, cause a bloom or increase the growth of algae. When too much algae grows, it can cause other plants to die and disturb the natural eco balance making it hard for fish and insects to survive. When this happens, it is referred to as a dead area.
  • Bacteria and other pathogens: All sorts of bacteria and pathogens can be washed into our waters. Many of these bacteria and pathogens cause illness if we swallow the water or it comes in contact with an open wound. This is often the reason beaches are closed.
  • Debris: Trash could be any kind of trash, from plastic bags, to cans, bottles, or cigarette butts. When trash washes into our water bodies it become detrimental to aquatic life.
  • Household hazardous wastes: Oil, antifreeze, pesticides, detergents, paints, fertilizer and many other pollutants can get washed from yards, driveways, parking lots and streets. These pollutants can harm and even kill aquatic life. It can be harmful to us if we eat fish, shrimp or crawfish that have been exposed to these pollutants.

Important Information

Water quality protection areas