Stormwater is precipitation that falls and runs over land and eventually into a river, lake, or ocean.
Why is it important?
When it rains, stormwater carries pollutants directly into creeks, streams, and lakes without being treated. The National Pollution Discharge Elimination System Phase Two Permit regulates municipalities’ stormwater dishcarges to help improve water quality.
Stormwater pollution can include dirt, soap, litter, pet waste, oil, fertilizer, pesticides, anything not permitted by the IDDE ordinance, the IDDE ordinance restricts non-approved discharges of water into the environment. There is however a lengthy list of approved discharges, they include things like firefighting discharges, and irrigation.
> Learn more about IDDE HERE (link)
From USGS Water science school: http://water.usgs.gov/edu/watershed.html
“When looking at the location of rivers and the amount of streamflow in rivers, the key concept is the river’s “watershed”. What is a watershed? Easy, if you are standing on ground right now, just look down. You’re standing, and everyone is standing, in a watershed. A watershed is the area of land where all of the water that falls in it and drains off of it goes to a common outlet. Watersheds can be as small as a footprint or large enough to encompass all the land that drains water into rivers that drain into Chesapeake Bay, where it enters the Atlantic Ocean
A watershed is an area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel. The word watershed is sometimes used interchangeably with drainage basin or catchment. Ridges and hills that separate two watersheds are called the drainage divide. The watershed consists of surface water–lakes, streams, reservoirs, and wetlands–and all the underlying ground water. Larger watersheds contain many smaller watersheds. It all depends on the outflow point; all of the land that drains water to the outflow point is the watershed for that outflow location. Watersheds are important because the streamflow and the water quality of a river are affected by things, human-induced or not, happening in the land area “above” the river-outflow point.”
“A stream is a body of concentrated flowing water in a natural low area or natural channel on the land surface (15A NCAC 02B .0233(2)). There are three stream types: ephemeral, intermittent, and perennial.
Ephemeral streams are features that only carry stormwater in direct response to precipitation. They may have a well-defined channel and they typically lack the biological, hydrological, and physical characteristics commonly associated with intermittent or continuous conveyances of water. These features are typically not regulated by NC DWR or the U.S. Army Corps of Engineers.
Intermittent streams have a well-defined channel that contains water for only part of the year (typically during winter and spring). The flow may be heavily supplemented by stormwater. When dry, they typically lack the biological and hydrological characteristics commonly associated with continuous conveyances of water. These features are regulated by NC DWR and typically regulated by the U.S. Army Corps of Engineers.
Perennial streams have a well-defined channel that contains water year round during a year with normal rainfall. Groundwater is the primary source of water, but they also carry stormwater. They exhibit the typical biological, hydrological, and physical characteristics commonly associated with the continuous conveyance of water. These features are regulated by NC DWR and typically regulated by the U.S. Army Corps of Engineers.”
From OMAFRA.gov– Soil erosion is a naturally occurring process that affects all landforms. In agriculture, soil erosion refers to the wearing away of a field’s topsoil by the natural physical forces of water (Figure 1) and wind (Figure 2) or through forces associated with farming activities such as tillage.
From MTU.edu “an ecosystem is a complex set of relationships among the living resources, habitats, and residents of an area. It includes plants, trees, animals, fish, birds, micro-organisms, water, soil, and people.
Ecosystems vary greatly in size and the elements that make them up, but each is a functioning unit of nature. Everything that lives in an ecosystem is dependent on other species and elements that re also part of that ecological community. If one part of an ecosystem is damaged or disappears, it as an impact on everything else.
When an ecosystem is healthy, scientists say it is sustainable. This means that all the elements live in balance and area capable of reproducing themselves there is usually biodiversity , meaning that there are a variety of living organisms and specie in that environment. “
Stormwater – Stormwater is precipitation that runs over land and eventually into a river, lake, or ocean.
Mitigate- to make less severe, to help fix
Infiltration- water soaking into the ground
Impervious- not allowing liquid to pass through
Nutrient pollution, one of America’s most widespread, costly and challenging environmental problems, is caused by excess nitrogen and phosphorus in the air and water.
- From: https://www.epa.gov/nutrientpollution/problem
- Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems. Nitrogen is also the most abundant element in the air we breathe. Nitrogen and phosphorus support the growth of algae and aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water.
- But when too much nitrogen and phosphorus enter the environment – usually from a wide range of human activities – the air and water can become polluted. Nutrient pollution has impacted many streams, rivers, lakes, bays and coastal waters for the past several decades, resulting in serious environmental and human health issues, and impacting the economy.
- Too much nitrogen and phosphorus in the water causes algae to grow faster than ecosystems can handle. Significant increases in algae harm water quality, food resources and habitats, and decrease the oxygen that fish and other aquatic life need to survive. Large growths of algae are called algal blooms and they can severely reduce or eliminate oxygen in the water, leading to illnesses in fish and the death of large numbers of fish. Some algal blooms are harmful to humans because they produce elevated toxins and bacterial growth that can make people sick if they come into contact with polluted water, consume tainted fish or shellfish, or drink contaminated water.
- Nutrient pollution in ground water – which millions of people in the United States use as their drinking water source – can be harmful, even at low levels. Infants are vulnerable to a nitrogen-based compound called nitrates in drinking water. Excess nitrogen in the atmosphere can produce pollutants such as ammonia and ozone, which can impair our ability to breathe, limit visibility and alter plant growth. When excess nitrogen comes back to earth from the atmosphere, it can harm the health of forests, soils and waterways.
Watersheds – The area that drains to a common waterway, such as a stream, lake, estuary, wetland, aquifer, or even the ocean.
- From: https://www.epa.gov/sites/production/files/2015-10/documents/faqs_healthy_watershed.pdf
- What is a Watershed? A watershed – the land area that drains to one stream, lake or river – affects the water quality in the water body that it surrounds. Like water bodies (e.g., lakes, rivers, and streams), individual watersheds have similarities but also differ in many ways. Every inch of the USA is part of a watershed – in other words, all lands drain into a lake, river, stream or other water body and directly affect its quality. Because we all live on the land, we all live in a watershed — thus watershed condition is important to everyone.
- Watersheds exist at different geographic scales, too. The Mississippi River has a huge watershed that covers all or parts of 33 states. You might live in that watershed, but at the same time you live in a watershed of a smaller, local stream or river that flows eventually into the Mississippi. EPA’s healthy watersheds activities mainly focus on these smaller watersheds.
Wetlands – Areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season.
- From: https://www.epa.gov/wetlands/what-wetland
- Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promote the development of characteristic wetland (hydric) soils.
- oWetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands
Stormwater Retrofit Definitions from the Town of Haw River JLK Stage 1 program
- BMP-Best Management Practice. Practices or programs that enhance water quality over a period of time.
- Eutrophication-An overabundance of nutrients in a body of water which results in algal blooms and poor water quality. In Jordan Lake these nutrients are Nitrogen and Phosphorous.
- Impervious-Property that is paved, graveled, or otherwise does not allow rain water to infiltrate into. Creates a high runoff volume of water and a high runoff of any stormwater pollutants on the surface.
- Jordan Lake Watershed-1,686 square mile drainage basin for Jordan Lake, and impoundment of the Haw River and New Hope Creek found in Chatham County.
- NC DEQ-North Carolina Department of Environmental Quality .
- NC DWQ-North Carolina Division of Water Quality. A division of NC DEQ and tasked with improving water quality in North Carolina’s streams, rivers, and lakes.
- NC DWQ BMP Manual-A manual produced by NC DWQ that provides information and requirements for structural stormwater devices, both new and retrofitted devices.
- Nitrogen-One of two pollutants of concern in the Jordan Lake Basin. Also one of the primary ingredients in fertilizer.
- Non-Structural Retrofits-Programs or measures that reduce pollution from the source within a municipality. Usually citywide but sometimes specific to individual watersheds within a town.
- Nutrient Loading-The act of nutrients being deposited in either soil or water. High Nutrient loading produces eutrophic bodies of water.
- Phosphorous-One of two pollutants of concern in the Jordan Lake Basin. Also one of the primary ingredients in fertilizer.
- Stormwater Administrator-The compliance person for stormwater programs. Ideally a permanent town or city employee, usually the planner or clerk.
- Stormwater BMP-A Best Management Practice that enhances water quality over time. Stormwater BMP can either refer to a program or a specific structural device.
- Stormwater Pollution-Anything that is carried by rain water downstream that is not rain water. This typically includes nutrients, fertilizer, sediment and other pollutants.
- Stormwater Retrofit-A device or program that is created or built to reduce existing stormwater pollution. Devices are structural stormwater retrofits and programs are non-structural stormwater retrofits.
- Stormwater Runoff-Runoff from rainwater. Stormwater runoff is everything that runs off of land and downstream after or during a rain event. Clean stormwater runoff should be just water and should not include any nutrients, fertilizer, sediment or other pollutants.
- Structural Retrofits-Stormwater Retrofit Devices that are built or installed downstream of existing sources of pollution. Typically these devices are constructed wetlands, water quality ponds, rain gardens, or other devices from the NC DWQ BMP Manual.