Here is a list of some definitions you should know concerning Flood mitigation, floods, flood damage, and flood insurance. You can see more here.
100-Year Flood- A 100-year flood does not refer to a flood that occurs once every 100 years, but to a flood level with a 1 percent chance of being equaled or exceeded in any given year.
Base Flood Elevation (BFE)- The elevation of surface water resulting from a flood that has a 1% chance of equaling or exceeding that level in any given year. The BFE is shown on the Flood Insurance Rate Map (FIRM) for Zones AE, AH, A1–A30, AR, AR/A, AR/AE, AR/A1– A30, AR/AH, AR/AO, V1–V30 and VE.
Base flow- Sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by groundwater discharges.
Community Rating System (CRS) - A program developed by FEMA to provide incentives for those communities in the Regular Program that have gone beyond the minimum floodplain management requirements to develop extra measures to protect from flooding.
Crest -The highest level of water reached by a flooding body of water, after which the water level begins to drop. Most rivers in flood experience multiple crests as additional snowmelt, rain, or obstructions (such as ice, levees or dams) affect their volume and flow.
Erosion - The process in which a material is worn away by a stream of liquid (water) or air, often due to the presence of abrasive particles in the stream.
FEMA - The Federal Emergency Management Agency, part of the Department of Homeland Security. The 10 Regional Offices of FEMA do most of the NFIP fieldwork and community coordination.
FIRM - Flood Insurance Rate Map; published by FEMA and provided to communities.
Floodproofing - Any combination of structural and nonstructural additions, changes or adjustments to structures, which reduce or eliminate the risk of flood damage to real estate or improved real property, water and sanitation facilities or structures with their contents.
Flood Stage - The level at which a body of water begins to flow over its banks and onto dry land, usually expressed in feet above sea level.
Freeboard -An additional amount of height above the Base Flood Elevation used as a factor of safety (e.g., 2 feet above the Base Flood) in determining the level at which a structure's lowest floor must be elevated or floodproofed to be in accordance with state or community floodplain management regulations.
Impermeable Layer - a layer of solid material, such as rock or clay, which does not allow water to pass through.
Lentic waters - Ponds or lakes (standing water).
Levee - A natural or humanmade earthen barrier along the edge of a stream, lake, or river. Land alongside rivers can be protected from flooding by levees.
Lotic Waters - Flowing waters, as in streams and rivers.
Maximum Contaminant Level (MCL) - The designation given by the U.S. Environmental Protection Agency (EPA) to water-quality standards promulgated under the Safe Drinking Water Act. The MCL is the highest amount of a contaminant that can be present in drinking water without causing a risk to human health.
National Flood Insurance Program (NFIP) - Provides affordable insurance to property owners, renters and businesses and encourages communities to adopt and enforce floodplain management regulations to reduce the impact of flooding on private and public structures.
Permeability - The ability of a material to allow the passage of a liquid, such as water through rocks. Permeable materials, such as gravel and sand, allow water to move quickly through them, whereas nonpermeable material, such as clay, doesn't allow water to flow freely.
Precipitation - Rain, snow, hail, sleet, dew, and frost.
Reservoir - A pond, lake, or basin, either natural or artificial, for the storage, regulation, and control of water.
Storm Sewer - A sewer that carries only surface runoff, street wash, and snowmelt from the land. In a separate sewer system, storm sewers are completely separate from those that carry domestic and commercial wastewater (sanitary sewers).
SFHA - Special Flood Hazard Area; the floodplain delineated on the FIRM as A Zones and V Zones.
Zone - A geographical area is shown on a Flood Hazard Boundary Map (FHBM) or a Flood Insurance Rate Map (FIRM) that reflects the severity or type of flooding in the area.