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Best Management Practices: Any practice used to help combat erosion and pollution. These practices could be simple, such as cleaning up pollutants and disposing of them properly, picking up trash, and installing silt fence at construction sites, or they could be more complicated, such as installing permanent low impact development devices or storm water retention ponds.
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Buffer Area: An area next to a water body that protects it from pollution and sediment runoff. This area is usually filled with plants, shrubs and trees that help slow down storm water and allow pollutants to naturally filter out before reaching the water.
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Chesapeake Bay Watershed: All the land that drains into the Chesapeake Bay. Includes parts of Virginia, West Virginia, Delaware, Pennsylvania, New York, Maryland, and all of the District of Columbia.
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Ecosystem: a combination of all the living and nonliving things in an area. An ecosystem could be the Rappahanock River, the organisms that live in it, and the other organisms, like birds and animals, that depend on it for food and water.
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Erosion: process by which sediment is loosened and carried away by water. Erosion can be natural, as in the Grand Canyon, or man-made, like erosion of sediment from construction sites.
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Estuary: an area (like the Chesapeake Bay) where fresh water and salt water mix. Ecosystems in estuaries can be very fragile, because of the specific conditions in which they exist.
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Evaporation: in the water cycle, a process by which water returns to water vapor and re-enters the atmosphere.
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Impermeable Area: an area that has a hard surface (like roads, parking lots, sidewalks and buildings). Impermeable surfaces do not allow storm water to sink back in the ground, instead the water must flow across the surface, picking up contaminants and increasing in velocity, until it reaches the river.
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Infiltration: process by which water enters the ground. Water seeps into the ground and enters the water table.
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Low Impact Development (LID): used to control storm water runoff in urbanized areas, LID practices help storm water infiltrate into the ground. Some practices are: rain gardens, vegetated swales, permeable pavement.
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Precipitation: the process of water falling from the sky to the ground. The water could be in the form of rain, snow, sleet, hail, ice or mist.
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Rappahannock River Watershed: land that drains into the Rappahannock River. Includes parts of the following counties: Albemarle, Caroline, Culpeper, Essex, Fauquier, Greene, King George, Lancaster, Madison, Middlesex, Northumberland, Orange, Rappahannock, Richmond, Spotsylvania, Stafford and Westmoreland, and all of the city of Fredericksburg.
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Sediment: any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. Excessive sediment can adversely affect the Rappahannock in several ways.
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Storm Water Runoff: water that falls from the sky and runs along the ground, instead of infiltrating into the ground or evaporating. Storm water runoff can be easily contaminated by pollutants it picks up. Storm water running along the surface can also cause erosion.
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Transpiration: part of the water cycle where water vapor is emitted from plants and sent back into the atmosphere.
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Tributary: any body of water that feeds into another. For example, the Rapidan River is a tributary of the Rappahannock River, which is in turn a tributary of the Chesapeake Bay.
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Velocity: the speed at which water flows. Too much velocity in storm water can cause erosion, therefore it is important to control the velocity of storm water in urban settings and at land disturbing sites. |