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Stormwater Info

Below is a list of words commonly used when talking about stormwater and their definition.

Clean Water Act: Put in place by the Federal Government to protect all bodies of water in the United States by reducing water pollution and preserving our lakes and rivers for aquatic life and recreation.

EPA:  Stands for the Environmental Protection Agency.

Erosion:  When dirt, soil, or sediment is washed away by stormwater.

Good Housekeeping: Ways of living and practices to reduce stormwater pollution.

Illicit Discharge: Anything other than stormwater that enters storm sewers, ditches, streams, and lakes.

Impervious Surface:Hard surfaces that prevent stormwater from absorbing into the ground.  Examples are roofs, cement driveways, roads, and sidewalks. 

Member Communities:Cities, townships and villages in Lake County that contract with the Lake County Stormwater Management Department to provide stormwater services.

NPDES:  Stands for National Pollutant Discharge Elimination System.  This is a regulatory program that prohibits or limits the release of pollutants into streams, lakes, and rivers.

Rain garden: A garden that is planted in a wet area of your yard with plants that can withstand water-logged soils.  A downspout can be directed to this garden to absorb the stormwater from your roof, therefore there will be less runoff to the storm sewers.

Sanitary Sewer:  A system of underground pipes that collect all the sewage from the houses in a neighborhood and carry it to a sewage treatment plant.

Sediment: Mud or dirt that is picked up by stormwater and washed into storm sewers and streams.  It often washes away from construction sites and land where there are no plants growing.

Septic System:  An on-lot system that collects the wastewater from your house and releases it into the soil underground to remove any bacteria and contaminants.  No wastewater leaves the property and all water stays underground.

Storm Drain:A metal drain in the street or on the tree lawn that carries only stormwater away from the yard and house.

Storm Sewer System:  Pipes under ground or ditches along the side of the road that carry stormwater to a river, stream, or lake.  Water entering the storm sewer system is not treated at a water treatment plant.

Stormwater Pollution:  Chemicals, dirt, leaves, grass clippings, sewage, or oil that is picked up by stormwater.

Stormwater runoff: Occurs when precipitation from rain or snowmelt flows over the ground, into storm sewers and drainage ditches, eventually flowing to streams and lakes. 

Urbanized Area: A city or town with a dense population.  As defined by the Census Bureau, is a land area comprising one or more central places and the adjacent densely settled surrounding area (urban fringe) that together have a residential population of at least 50,000 and an overall population density of at least 1,000 people per square mile.

Watershed: No matter where water falls in this area of land, the water will flow downhill to the same point.  Think of a watershed like a big bowl.

Wetland: An area of land that stays wet or is covered with water a certain period of time over the course of the year and has certain plants that only grow in wet areas.


(Cited from O.BERK®)

The water supply of Earth is a required element for life to exist and thrive. The water cycle is a continuous cycle that keeps water moving on and around Earth in different forms. The different stages of the water cycle include evaporation, condensation, precipitation, and collection. Each stage of the cycle leads to the next stage, and each stage is an important part of a process that helps to water plants, fill cisterns, dry up puddles, and remove floodwaters.

Aquifer: An aquifer is an underground layer that contains groundwater.

Atmosphere: A unit of atmosphere measures the air pressure at sea level, which is about 14.7 pounds per square inch.

Climate: The climate of a location includes all of the weather conditions for this location over an extended period of time.

Cloud: A cloud is a visible mass of small water droplets or tiny ice crystals that are suspended in the atmosphere.

Cloud Condensation Nuclei: Water vapor surrounds tiny particles, condensing in clouds to become raindrops.

Condensation: Condensation is the process by which water vapor changes into liquid.

Current: Currents are predictable and steady flows of fluid in a larger body of fluid.

Density: Density describes the amount of things in a specific space.

Dew Point: Dew point is the temperature at which water in the air condenses to become water droplets near the ground.

Ecosystem: An ecosystem is a community of living and nonliving things in an area.

Erosion: Erosion happens when soil is worn away, usually by wind, water, or ice.

Evaporation: Evaporation is the process of water changing into water vapor.

Evapotranspiration: When moisture from the soil evaporates into the atmosphere or when transpiration from plants occurs, this is called evapotranspiration.

Fog: Clouds near the ground are known as fog.

Freshwater: A lake, river, or spring is a source of freshwater, which animals can drink.

Glacier: A glacier is a mass of ice that moves slowly across a land mass.

Great Lakes: The Great Lakes are the biggest freshwater bodies of water in the world, located in the United States.

Greenhouse Gas: Gases in the atmosphere that absorb solar heat reflected by Earth’s surface, contributing to warming of the atmosphere, are greenhouse gases.

Groundwater: Groundwater is water found in an aquifer.

Humidity: The amount of water vapor in the air is the humidity.

Ice: Ice is water in solid form.

Ice Cap: An ice cap is an area of less than 19,000 square miles covered by ice.

Ice Sheet: Ice sheets are glacial ice areas that cover a large expanse.

Lake: A lake is a body of water that is surrounded by land.

Microscopic: Microscopic describes something very small.

Pollutant: A pollutant is a substance that harms a natural resource.

Precipitation: Precipitation includes all types of water that fall to Earth.

River: A river is a big stream of fresh water that flows.

Runoff: When fluid overflows from a farm or factory, it’s known as runoff.

Snowmelt: Melted water from snow is snowmelt.

Temperature: The level of heat or cold, measured by a thermometer, is temperature.

Transpiration: Water that evaporates from plants is transpiration.

Vapor: Vapor is liquid that is suspended in air.

Water Cycle: Water moves between the land, bodies of water, and atmosphere in a process known as the water cycle.

Weather: Weather describes the state of the atmosphere, and it includes atmospheric pressure, temperature, humidity, cloudiness, precipitation, and wind.

Wind: Wind is air that moves from areas of high pressure to low-pressure zones.

(Special thanks to Ms. Pedersen, Amelia and their group for making us aware of this list of water cycle definitions!)