FLOOD03394

• Designation Number: 505
• County: Jefferson
• Community: Unincorporated Jefferson County
• Basin: South Platte
• Title: Flood Insurance Study - Jefferson County, CO, Unincorporated Areas
• Date: 4/1/1989
• Designation Date: 9/1/1999
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

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GLOSSARY OF TERMS

CHANNEL - A natural or artificial water course of perceptible
extent with definite banks to confine and conduct continuously
or periodically flowing water. Channel flow is that water
which is flowing within the limits of the defined channel.

FLOOD - Water from river, stream, water course, lake or other
body of standing water, that temporarily overflows the
boundaries within which it is ordinarily confined.

FLOOD CREST - The maximum stage or elevation reached by the
waters of a flood at a given location.

FLOOD FREQUENCY - A means of expressing the probability of flood
occurrences as determined from statistical analysis of
representative stream flow or rainfall and runoff records.
The frequency of a particular stage or discharge is usually
expressed as occurring once in a specified number of years.
The 10-, 25-, 50-, 100-year frequency floods have an average
frequency of occurrence in the order of once in the number of
years indicated.

FLOOD HAZARD AREAS - Areas susceptible to flood damage.

FLOOD PEAK - The highest stage or discharge attained during a
flood event; also referred to as peak stage or peak discharge.

FLOOD PLAIN - The relatively flat or lowland area adjoining a
river, stream, watercourse, lake, or other body of water which
has been or may be covered temporarily by flood water. For
administrative purposes the flood plain may be defined as the
area that would be inundated by the 100-year flood.

LEFT or RIGHT STREAM BANK - The left or right bank of the stream
looking downstream.

PERCHED CHANNEL FLOW - A condition where the flow elevation in
the outer portions of the flood plain is higher than the flow
elevation in the main channel. This condition occurs when a
secondary channel receives inflow from some location upstream
and maintains a flatter slope then the main channel.

REACH - A hydraulic engineering term used to describe
longitudinal segments of a stream or river.

RUNOFF - That part of precipitation, as well as any other flow
contributions, which appears in surface streams of either
perennial or intermittent form.

STREAM - Any natural channel or depression through which water
flows whether continuously, or intermittently, including
modification of the natural channel or depression.

STRUCTURE - Anything constructed or erected, the use of which

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