Definitions

FEMA: The Federal Emergency Management Agency (FEMA) is a department of Homeland Security and responds to major emergencies where state and local agencies need additional resources to handle. FEMA also seeks to reduce the loss of life and protect property against hazards through a comprehensive, risk-based emergency management program.

Detention Basin: A basin or reservoir where excess stormwater runoff is stored as a way to regulate the flow of quantity (and quality if appropriate) of water downstream.

Drainage Basin: Land area drained by a creek, stream or river. Drainage basin, drainage area, tributary area and watershed are interchangeable terms.

Flood: A temporary condition caused by the accumulation of stormwater runoff from any source that exceeds the capacity of a natural or man-made drainage system and results in the inundation of normally dry land areas.

Flash Flood: The result of heavy or excessive amounts of rainfall within a short period of time, usually less than six hours, causing water to rise and fall rapidly.

Floodplain: An area that adjoins a watercourse and may be inundated by water from a rainfall event of a designated duration and intensity.

Federally Mapped Regulatory Floodplain: A high risk flood-prone area that has been mapped and accepted by the Federal Emergency Management Agency (FEMA) as the result of a flood insurance study (FIS) for a creek, stream or river. Mapped floodplains help identify the risk of flooding and are used for flood insurance and other regulatory purposes.

Flood Insurance Study (FIS): Hydrologic and hydraulic studies that identify a flood hazard area, flood insurance risk zones and other flood data, such as flood depths and velocities.

Flood Insurance Rate Map (FIRM): FEMA-issued maps identifying flood hazard areas, including the 1 percent floodplain as well as flood insurance risk zones and other flood-related information.

Floodplain Management: A stormwater management effort that uses corrective and preventative measures to reduce flood and preserve natural habitat and wildlife resources in flood-prone areas.

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JOHNSON COUNTY STORMWATER MANAGEMENT PROGRAM
1800 W. 56 Highway
Olathe, KS 66061
Phone: (913) 715-8333
Fax: (913) 715-2453