Stormwater 101
The Basics:  When you take a shower or a bath,  all the dirty water goes down the drain, through sewer pipes to a wastewater treatment plant. Here, the dirty bath water is cleaned and filtered before it is returned to the environment.
Rain is like a shower or bath for all things outdoors. All the dirt, grime, grease, oil and waste that is on our buildings, in our yards, on the streets, driveways and parking lots is washed away down a storm drain.  Only the storm drain doesn't take the dirty water to the wastewater treatment plant for cleaning. Instead it flows directly into our streams, lakes and rivers.
All of this dirt, grime, and yuck is polluting our water. Take a look at some stormwater problems that may be around your home, school, or neighborhood. When rain falls in your school yard or in your neighborhood, where does it land? While this might seem like a simple question, its answer can tell you a lot about controlling runoff in your yard or at your school.  If rain falls on paved or impervious surfaces (like roads, driveways, or rooftops), almost all of the water will run off. If rain falls on grassed areas   more than 50% of the water may still runoff the surface, depending on soil and rainfall characteristics. 
If rain falls on areas planted in dense shrubs and trees, very little water will have a chance to run off, and most will sink into the soil. Impacts of Stormwater Runoff: The most dramatic consequence of stormwater runoff may be flooding and the damage it brings.  Stormwater runoff is channeled directly to streams or rivers that cannot handle the additional fast flow of water. The stormwater runoff becomes floodwater when it overtops the stream banks and floods streets, businesses and homes.
Flooding is not the only impact! Stormwater runoff results in: stream, lake and river impairment, waterbodies with high levels of fecal bacteria from farm animal and pet poop, of which e coli is a type, and it contributes to cultural eutrophication.
 Water is classified as eutrophic when there is excess nutrients (like fertilizer) in the water. These nutrients result in algae growth, as well as other unwanted aquatic plant growth. The water becomes biologically productive, which means bacteria can grow and thrive - robbing the water of oxygen - and results in fish kills and destruction of natural habitat.
All lakes will naturally become eutrophic over time... ...where time is measured in hundreds or thousands of years. However, stormwater runoff results in cultural eutrophication. This is an artificial and accelerated process due to human activity. It can be controlled by managing human activity in the watershed. Watersheds:  So what is a watershed?
What is a river basin? What is a sub basin? In what sub basin do you live? Why is a watershed important? Links to websites with additional information Glossary of terms
So what is a watershed? -Any size area of land that catches all the rain or snow and drains the water into a marsh, stream, river, lake or groundwater. Technically speaking, a river basin and a sub basin are different sized watersheds. However, it is common to use the term "watershed" when talking about watershed areas that are smaller than a basin or sub-basin. What is a river basin - A river basin is a large-scale watershed, such as the Cape Fear River Basin, or the Yadkin Pee Dee River Basin. What is a Sub-basin - Sub-basins are smaller scale basins, such as the Haw River Sub Basin and the Deep River Subbasin within the larger Cape Fear Sub Basin. Can you figure out which subbasin you live in? Major river basins and sub basins within our region: Click on the maps below to find out which sub basin you live in Why is knowing my watershed so important? We all live in a watershed. Our homes, schools, where we work and where we play are in a watershed. We need clean water to live. Everything we do on land impacts the quality and quantity of water in a watershed. Watersheds provide water for drinking, washing, irrigation, business and industry. Lakes and streams provide opportunities for boating, fishing and swimming. If the water is not clean, then we may not be able to use it for drinking, irrigation, or recreation. When that happens, the stream, lake, river or creek is "impaired" and placed on the Environmental Protection Agency and North Carolina 303(d) list. The 303 (d) list refers to Section 303(d) of the Clean Water Act (CWA.) The list names waterbodies that do not meet water quality standards or have impaired uses. | 
