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What is Stormwater?

What is Stormwater?

Stormwater is water from rain or melting snow that doesn't soak into the ground but runs off into waterways. In urban areas, runoff is usually transported via gutters, storm drains, catch basins, underground pipes, open channels, ditches and culverts. As the runoff flows over the land or impervious surfaces (such as paved streets, parking lots, and building rooftops), it may accumulate debris, chemicals, sediment or other pollutants that could adversely affect water quality in the receiving waterbody. For this reason, we should try to limit impervious surfaces if possible. Since impervious surfaces allow very little water to penetrate the ground, it tends exacerbate flooding by transporting larger volumes of polluted water, more rapidly to streams, rivers and lakes. Conversely, vegetated or pervious surfaces allow water to penetrate the ground where soil cleanses the water, and where vegetation itself can cleanse runoff and slow the transport of water to receiving bodies of water. Polluted runoff may impact lakes, rivers, wetland and other waterways in a variety of ways. For example, transported soil may cloud the waterway and interfere with the habitat of fish and plant life. Nutrients such as phosphorus and nitrogen (that are often found in fertilizer) can promote the overgrowth of algae, deplete oxygen in the waterway and be harmful to other aquatic life. Toxic chemicals from automobiles, sediment from construction activities and careless application of pesticides and herbicides threaten the health of the receiving waterway and can kill fish and other aquatic life. Bacteria from human and animal wastes can make nearby lakes and streams unsafe for wading, swimming and the propagation of edible fish. According to an inventory conducted by the United States Environmental Protection Agency (EPA), half of the impaired waterways studied are affected by stormwater runoff originating in urban/suburban areas and construction sites. Stormwater management, especially in urban areas, is the focus for seeking further reductions in pollution in waterways.

Fact Sheets and Miscellaneous Stormwater Publications: Informing residents and businesses about potential water quality impacts that may be caused by polluted stormwater runoff is key to our stormwater program. Below is a list of Stormwater Fact Sheets and miscellaneous publications, geared toward the general public, that outline potential impacts from polluted stormwater runoff and/or steps the community can take to reduce those pollutants.

Healthy Household Habits For Clean Water
Download • 41KB
Lawn Care Fact Sheet
Download PDF • 887KB

Protecting Water Quality From Urban Runo
Download • 408KB

Storm Sewer vs. Sanitary Sewer
Download PDF • 60KB

There are two types of sewers, sanitary sewers and storm sewers. Sanitary sewers transport household wastes (such as toilet and shower waste) and certain industrial wastes to sewage treatment plants or septic systems where the water is treated before it re-enters the environment. Storm sewers transport rain and snow melt water from our streets, parking lots, rooftops and landscape to nearby streams, rivers, lakes and oceans. While these two sewers are usually separate systems, some older municipalities have portions of their system that are combined. A Combined Sewer Outflow (CSO) occurs when a sanitary sewer and storm sewer line is connected and outlets to a surface water body, usually after a significant rainfall event. Since the combined sewer pipe and sewage treatment plant cannot handle the added water flow during significant storm events, it exits at the combined sewer outflow. This often leads to surface waters being polluted by sanitary sewage.

Why Should We Care
Download PDF • 74KB

Take a look at the following link at the Environmental Protection Agency website that describes three videos that can be either streamed or downloaded regarding Stormwater issues.

Overview of Green Infrastructure Fact Sh
Download • 4.94MB

Links to Other Stormwater Related Agencies and Organization:

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