Acquisition Program (Buyout Program): A voluntary program in which the government enters into negotiations for the purchase of eligible, privately-owned property in the floodplain to demolish or relocate the structure and to convert the land to be used as open space. Learn more.
Aquatic: Living or growing in or on the water
Bacteria: Single cell organisms found in nearly every environment on Earth. In large amounts, some types of bacteria such as fecal coliform are harmful to the quality of surface water.
Base Flood Elevation: The depth of floodwater associated with a 100-year flood or a flood with a 1% chance of occurring in any given year. The Base Flood patterns provide the guidelines for the National Flood Insurance Program rates and floodplain management regulations.
BMP or Best Management Practice: Methods, measures, or practices designed to prevent or reduce water pollution. Storm Water BMPs can include rain gardens, wetlands, infiltration structures, sediment retention ponds, vegetation strips and grassy swales. See examples of Pilot BMPs in Charlotte-Mecklenburg.
Bioengineering: The study and use of engineering techniques to manage resources such as water and soil, or even in health care and medicine
Bioretention: Various types of storm water Best Management Practices that use engineering techniques, soils and specially-chosen plants to remove pollutants from storm water runoff
Buffer: Undeveloped land covered with plants alongside a stream or lake that absorbs some storm water runoff and pollutants carried by the runoff
Built Upon Area: Portion of developed land that is covered by impervious or semi-impervious surface such as buildings, and pavement or gravel areas such as roads and parking lots
Buyout Program (Acquisition Program): A voluntary program in which the government enters into negotiations for the purchase of eligible, privately-owned property in the floodplain to demolish or relocate the structure and to convert the land to be used as open space.
Channelize: Engineering technique where the path of a stream is straightened. Often, a concrete path is created to hold the channelized stream water. Channelizing is often ineffective because it increases the speed and danger of the water flow and it removes the natural habitat for aquatic life.
Compost Bin: A container to hold organic materials such as grass clippings, leaves, fruit and vegetable waste like peels or skins, coffee grounds and egg shells while that material decomposes. Compost can then be used as mulch or to loosen and enrich poor soil.
Condensation: The process in the water cycle by which a vapor becomes a liquid; the opposite of evaporation
Conservation: The use of water-saving methods to reduce the amount of water needed for homes, lawns, farming, and industry, and thus increasing water supplies for optimum long-term economic and social benefits
Conservation Easement: Voluntary legal agreement between a landowner and organization (government agency or land trust) that permanently limits some of the land's uses, primarily the right to develop the land
Contaminant: Any substance that when added to water (or another substance) makes it impure and unfit for consumption or use
Community Rating System (CRS): A program managed by the National Flood Insurance Program (NFIP) to provide incentives for those communities that go beyond the minimum floodplain management requirements to develop extra measures to provide protection from flooding
Detention Basin: Temporary holding areas placed in the stormwater drainage system to temporarily store excess runoff that results from heavy rainfall
Development: Any manmade change to improved and unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavating or drilling operations
Discharge: Water that flows from a stream, pipe, groundwater aquifer, or watershed
Drainage Basin: The area of land that drains to a given point on a body of water
Dry Weather Flow: Runoff that enters the storm water drainage system from every day activities as car washing and lawn watering. Dry weather flow usually has a higher concentration of harmful nutrient chemicals and bacteria than does flow that results from rainfall.
Easement: An agreement that allows the government or a person to use private property for a specific purpose, such as to install and maintain storm drainage pipes. Learn more.
Ecosystem: The biological community (living plant and animals) and the non-living environment (water, rocks, chemicals, weather systems) functioning as one system
Erosion: The wearing away of the earth's surface by running water, wind, ice, gravity or other natural or man-made agents
Evaporation: The conversion of a liquid (water) into a vapor (a gaseous state) usually through the application of heat energy during the hydrologic cycle; the opposite of condensation
Fecal Coliform Bacteria: A type of bacteria found in the intestines of humans and animals. The presence of fecal coliform bacteria in water is an indicator of a potential health risk for individuals exposed to this water. Fecal coliform can enter waterways through sewage treatment plant discharge, sewage pipe overflows, or from pet and wild animal waste.
FEMA (Federal Emergency Management Agency): A federal agency within the Department of Homeland Security with the responsibility of responding to, planning for, recovering from and mitigating against disaster.
Fertilizer: A substance used to increase growth of a plant or improve the quality of a crop. When used inappropriately, it can contribute to storm water pollution
Filtration: The act of filtering, such as removing pollutants and sediment from storm water runoff
Flash Flood: Sudden flooding cause by an intense storm dropping large amounts of rain within a brief period. A flash flood occurs with little or no warning
Flood: A large flow of water over normally dry land, especially one that causes loss or damage. The National Flood Insurance Program defines a "flood" as a general and temporary condition of partial or complete inundation of normally dry land areas from:
(1) the overflow of inland or tidal waters; and,
(2) the unusual and rapid accumulation of runoff of surface waters from any source.
Floodplain management: An overall community program of corrective and preventive measures for reducing future flood damage. These measures generally include zoning, building requirements and special-purpose floodplain ordinances
Flood Fringe: The outer portion of the flood risk area next to the flood way. The flood water in the flood fringe is generally shallower and flows more slowly than in the floodway. Conditions in the flood fringe are generally less hazardous than in the floodway.
Flood Insurance: Federally-backed policies available to homeowners, renters and business owners that, unlike standard homeowner's insurance, cover flood damage and loss
Flood Insurance Rate Map (FIRM): The official map that marks both the special hazard areas and the risk premium zones that apply to the community. This map is used by the Federal Emergency Management Agency to determine flood insurance rates. Mecklenburg County also uses flood maps to regulate land development. Learn more.
Flood Warning: Flooding is actually occurring or very likely to occur in the warning area
Flood Watch: Flooding is possible in a specific area during a given time period. These watches are generally issued for flooding that is expecting to occur at least six hours after heavy rains have ended.
Flood Zone: An area of land shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map that reflects the severity or type of flooding in the area. Everyone lives in a flood zone—it's just a question of whether a person's risk is low, medium or high.
Floodplain: Areas that are flooded periodically by the overflow of rivers, creeks, streams or lakes. Mecklenburg has 334-miles of FEMA-regulated floodplain
Floodplain Bench: A level area of land along a creek where floodwater is allowed to temporarily spill outside the main channel. This reduces stream bank erosion and stabilizes the creek bank.
Floodplain Management: A comprehensive program of corrective and preventive measures for reducing flood damage such as floodplain regulations, emergency preparedness plans and flood control operations
Floodway: The portion of the flood risk area where flood waters are the deepest, fastest and most destructive
FLUM (Floodplain Land Use Map): Flood maps developed by Mecklenburg County and used to regulate new development
Gabion basket: Wire basket filled with rock and placed along the stream banks to reduce erosion
Grandfathering: Allowing an existing structure or property use to remain even though it does not comply with restrictions or regulations that were approved after it was built
Grass Swale: A Low Impact Development technique that uses a specially-designed drainage ditch planted with thick grass to slow the flow of storm water runoff and filter pollutants such as sediment and excess nutrients.
Greenway: A recreational trail for the public in a floodway that is usually surrounded by trees or plants
Habitat: Place where a plant, animal or microscopic organism naturally lives and grows
Hazard Mitigation Program: A program run by the Federal Emergency Management Agency (FEMA) and North Carolina Division of Emergency Management to protect lives and property from natural and human-made hazards such as flooding.
Hazardous waste: Any discarded solid, liquid, or gaseous material that can harm humans or animals
Headwaters: The beginning point of a stream or upper reaches of a stream near its source
Hydrologic cycle: Also known as the water cycle. The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the ocean, atmosphere, streams and groundwater.
Hydrology: A science dealing with the properties, distribution and circulation of water
Illicit Connection: Any connection to the storm water drainage system that is not permitted, or a legal connection that is used for illegal purposed such as to dispose of pollutants such as wastewater from a Laundromat, car wash or similar business
Illicit Discharge: Any disposal into the storm drain system for which a person or business does not have a permit
Impaired waters list: Creeks, streams or other bodies of water that do not meet state water quality standards. Under Section 303(d) of the Clean Water Act, states are required to develop lists of impaired waters. Learn more.
Impervious area: Surface that water cannot penetrate such as rooftops, parking lots, driveways and roads. Areas with more impervious surfaces generally contribute more to storm water runoff pollution and the amount (volume) of storm water runoff.
Infiltrate: Water sinks slowly into the soil, reducing the amount that runs off and allowing pollutants to be absorbed naturally
Infiltration Trench: A rock-lined trench designed to hold storm water runoff and allow it to seep into the soil or groundwater, filtering out pollutants and reducing erosion
Invasive Plants: Plants that were brought to this area by humans and are not native to this area. They spread rapidly and uncontrollably. Some examples include kudzu, Japanese honeysuckle, mimosa and nandina.
Levee: A man-made structure, usually an earthen dike, designed to contain, control or divert the flow of water to provide protection from temporary flooding
Level Spreader: A BMP designed to spread storm water across the ground in a level manner, allowing pollutants to be filtered through plants and special types of soils
Low Impact Development (LID): The use of special landscaping techniques to reduce the impact that land development has on water quality. Rather than letting storm water run off or forcing it into a drainage and pipe system, LID captures storm water on site, filters it through vegetation and lets it gradually soak into the ground or into streams. Learn more.
Macroinvertebrates: Creatures without backbones that are large enough to be seen without a microscope, such as snails, worms, fly larvae, and crayfish ("crawdads"). Certain organisms can survive only in water that's very clean, so finding those in water samples means the water is probably healthy.
Meanders: Freely-swinging, winding stream channels
Mitigate: To minimize; lessen the severity
Monitor: To observe a system for changes and keep records of the data collected
National Flood Insurance Program (NFIP): A program that provides flood insurance coverage through private insurance companies for personal and business property. Damage claims and the cost of operating the program are funded through insurance premiums, not tax dollars. Learn more.
National Pollutant Discharge Elimination System (NPDES): A federally-mandated program through the Clean Water Act that regulates pollutants discharged directly into the surface water system
Nitrogen: A nutrient essential to both plants and animals. It is a key ingredient in fertilizer. Too much can act as a pollutant, causing algae blooms and fish kills.
Non-point source pollutants: Pollution that cannot be traced to a single point because it comes from many individual places or a widespread area
Nutrient: An element or compound, such as nitrogen, phosphorous, and potassium that is necessary for plant growth. If there are too many nutrients in a stream or lake, that can cause an overgrowth of algae and other plants that kill fish and other aquatic life.
Nutrient pollution: Human-caused addition of excess nutrients, such as grass clippings and pet waste that is carried to creeks, lakes and rivers by storm water runoff
100-year flood: More accurately referred to as a "one percent chance flood." There is a 1% chance that a flood this large will happen in that area in any given year.
100-year floodplain: The land adjacent to a river, lake, creek or stream that has a 1% chance within any given year of being inundated by water during a flood. Also called Special Flood Hazard Area (SFHA)
Open Space: Natural areas containing no buildings or other development
Outfall: The place where a sewer, drain or stream empties
Pervious: Surface that allows water to seep into the ground
Phosphorus: A plant nutrient and an essential ingredient in fertilizer. High levels of phosphorus can cause algae blooms and fish kills.
Pocket wetlands: Small wetlands close to a stream that hold flood water that has spilled over the banks
Point Source Pollution: A type of pollution that can be traced to a specific source such as a factory or sewage treatment plant. Most of this type of pollution is highly regulated at the state and federal levels.
Pollutant: Something that makes the water, land or air dirty and unhealthy
Pollutant Loading: The transfer of pollutants from one place to another, such as sediment carried by storm water runoff into a stream
Pollution: The act or process of contaminating the soil, water or atmosphere by the release of harmful substances
Pool: Deeper area of a stream or river that slows the speed of the water flow and provides habitat for certain types of fish and aquatic life
Precipitation: The part of the hydrologic cycle when water, in a liquid or solid state, falls from the atmosphere to Earth, such as rain or snow
Rain Barrel: A large container placed underneath a downspout to capture and hold rain water
Rain Garden: A small depression dug into the ground, then landscaped with specially-chosen plants. The rain garden collects and stores excess water, allowing it to slowly seep into the soil. The roots of the plants absorb many pollutants, keeping them from entering our streams and lakes. Also referred to as a Bioretention cell.
Restoration: Correcting damage done to a stream, to include stabilizing the stream bank, restoring the path of the stream to a more natural design, slowing the flow of the water, providing for flood water storage, improving water quality and enhancing the habitat for plants and aquatic life
Retrofit: To install a new BMP or improve an existing BMP near existing buildings, roads or parking lots
Riffle: A section of river or stream with rapid, turbulent flow; generally shallow. Riffles add oxygen to the water that supports wildlife.
Riparian buffer: Area of grass, shrubs or trees alongside a stream or body of water. The buffer provides shade for the stream and filters pollutants from storm water runoff.
Riprap: Large rocks or broken concrete used to stabilize stream banks or other slopes
Runoff: Rain water that flows across surfaces rather than soaking into the ground. It may pick up and carry a variety of pollutants before eventually entering a creek, river or lake. Storm water runoff in Charlotte-Mecklenburg is not treated before it goes into the creeks or lakes.
Scour: The removal of particles of soil and rock by fast-moving water. Scoured stream banks can become unstable and can cause bridge supports to become unsafe or even collapse.
Sediment: Loose particles of clay, soil and sand that are released from the earth's surface through erosion. Sediment is a pollutant because it eventually settles to the bottom, smothering aquatic life and interfering with the flow of the stream.
Special Flood Hazard Area (SFHA): A land area that is at high risk for flooding. SFHA's are often called floodplains and are indicated on Flood Insurance Rate Maps. A home located within an SFHA has a 1% chance of flooding in any given year and 26% chance of suffering flood damage during the term of a 30-year mortgage.
Storm water wetlands: An area of land designed with particular types of soils to hold excess storm water runoff and specially-chosen plants to absorb pollutants from the runoff
Stream enhancement: Improving the design and flow of a stream, creating structures in the streambed and banks where aquatic life, wildlife and plants wildlife can live, reshaping and stabilizing the stream bank, and providing for flood water storage
Stream restoration: Correcting damage done to a stream, to include reshaping and stabilizing the stream bank, restoring the path of the stream to a more natural design, slowing the flow of the water, providing for flood water storage, improving water quality and enhancing the habitat for plants and aquatic life
Stream structures: Typically large flat stones that are placed in the stream bed to create a ripple effect in the stream during low flows. The ripple effect can increase levels of dissolved oxygen which may make the water purer and more able to support aquatic life.
Substantial Damage: Damage of any origin to a structure in which the cost of repairing that structure would equal or exceed 50% of the market value of that structure before the damage occurred. In Mecklenburg County, substantial damage also means flood-related damages sustained by a structure on two separate occasions during a 10-year period beginning after September 8, 1999, for which the cost of repairs at the time of each such flood event equals or exceeds 25% of the market value of the structure before the damage occurred.
Substantial Improvement: Any repair, reconstruction, or improvement of a structure, where the cost equals or exceeds 50% of the market value of the structure, either (1) before the improvement or repair is started, or (2) if the structure has been damaged and is being restored, before the damage occurred. In Mecklenburg County, substantial improvement also means any repair, reconstruction, or improvement to a structure on two separate occasions during a 10-year period beginning after September 8, 1999, for which the cost of repairs, reconstruction, or improvement at the time of each alteration equals or exceeds 25% of the market value of the structure before the alteration occurred. Substantial Improvement does not, however, include either any project for improvement of a building to correct existing state or local code violations or any alteration to a "historic building," provided that the alteration will not preclude the building's continued designation as a "historic building."
Surface water: An open body of water such as a stream, river, pond, lake or reservoir
SWIM buffer (Surface Water Improvement and Management buffer): An area along streams, lakes and waterways that cannot be cleared of vegetation or developed. The size of the SWIM buffer is defined by local ordinances. The buffers are one aspect of a multi-faceted SWIM program designed to reduce pollutant levels in local streams and lakes. Learn more.
Total Maximum Daily Load (TMDL): Total amount of pollutants that a stream can contain without impairing the water or violating clean water laws. Learn more.
Total Suspended Solids (TSS): The amount of tiny particles of solid matter contained in a water sample. The amount of TSS is a way to measure water quality.
Tributary: A smaller stream that flows into a larger river, creek or stream
Wastewater: Water in the sanitary sewer system which comes from sinks, toilets, showers, washing machines, etc. Wastewater is not the same as storm water runoff. Wastewater is treated before being released into the creeks. Storm water runoff is not treated in Mecklenburg County.
Watershed: A region of land drained by a single stream, river or drainage network. Also known as a drainage basin
Water cycle (also known as the hydrologic cycle): The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the ocean, atmosphere, streams and groundwater
Water Pollution: Any human or animal-caused contamination of water that reduces its usefulness to humans and other living things
Water Quality: The chemical, physical and biological condition of water, usually in respect to whether it is suited for a particular purpose such as supporting aquatic life
Water Quality Monitoring: Regular testing of water from lakes and streams to determine how healthy it is. Scientists measure the temperature; amount of oxygen; levels of certain bacteria, metals and toxic chemicals; and turbidity or how clear the water is. Scientists also count the number of fish, insects, plants and small organisms like snails, worms and insect eggs.
Waterway: A natural or man-made place for water to run through, such as a river, stream, creek or channel
Wetland: A collective term for land areas such as swamps or marshes that are wet because they are close to a body of water or are flooded regularly. Wetlands can be created by nature or by people. Wetlands store flood water and are effective at removing certain pollutants from storm water runoff.
Wet pond: Also called a storm water pond. These are created to store runoff during and after storms, reducing flood risks. The water is slowly released into the stream. Besides reducing flood risks, wet ponds also filter out pollutants by allowing sediment to settle and by plants that absorb excess nutrients from the runoff.
Yard waste: Leaves, grass clippings, yard and garden debris that result from yard care.
