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<br />GLOSSARY OF TERMS <br /> <br />Flood <br /> <br />FloodStaqe <br />The st~ae or elevatIon at which overflow of the n~tural <br />banks of a streamorOOdyof Wi'ltar begins In the reach or area In <br />w~lch the elevatIon 15 measured. <br /> <br />An overflow on lan1s not normally covered by water and <br />that are used or usable by man. Floods havn two essential char- <br />acteristics: Theinunda+-ionof land istell'lporary; and the land <br />15 adjacent to and inundated by overflow from a rIver or stream or <br />anoce<ln,l1Ike,orotherbodyofstllndlngwater. <br />Normally a fiood Is consi<lered liS any temporary rise In <br />stream flow or stage, but not the pondln~ of surface water, that <br />results In significant adverse effects in the vIcinity. Adverse <br />effects may Include damages from overflow of land areas, temporary <br />backw1lter effects in SewerS and local draln~ge channels, crea+-ion <br />of unsanItary conditIons or other uniavorahle situations by deposI- <br />tion of materials In stream channels during ilood recessions, rIse <br />of ground water coincident with increased stream flow, and other <br />problems. <br /> <br />Head loss <br /> <br />The offect of obstructIons, such as narrow bridge open- <br />ings or buildings that limit the area through which w~ter must <br />flow, raising the surface of the water upstream from the obstruc- <br />tion. <br /> <br />Left Bank <br /> <br />The bank on the lett side of a river, stream, or water <br />course. looking downstream. <br /> <br />Ri<1hfBank <br /> <br />Flood Crest <br />The maximum st~ge or elevation re~ched by tho waters 01 <br />a flood at a given locatIon, <br /> <br />The bank on the rIght side of a rIver, stream, or water <br />cOurSe looking Jownstream. <br /> <br />FlOOd PI'lln <br />The relatively flat ~re~ Or low land5 adjoIning the <br />ch~nnel of a river, stream, water courso or ocean, I ake or other <br />body of standing water, whIch has been or may b~ covered by <br />floodw",ter, <br /> <br />10-Year. 50-Year, 100-Yoar. SOO-Year FlOOd <br />A flood having a 10, 2, I, and .2 percent prob~blllty. <br />r~spec+lvely. of occ~rrenco in any year or an 1lvoraqe frequency of <br />occurrence In the order of Once In 10, 50. 100. and 500 years, <br />respectively. Tholloodmayoccurlnanyyear. Itlsbas"don <br />statistical anaiysls of str~~"llow r~cords end analysis of rain- <br />fall an1 runoff characteristics In the qenoral region of the <br />watershAd. <br /> <br />FloO<JProfil.. <br />A graph showIng the relationshIp of water surface elo- <br />vation to location, the I atter genera Ily expressed as di st~nce <br />above mouth for a stream of water f lowing In an open channel. It <br />Is oenerally drawn to show surface elevation forthecrestofa <br />speciflcflood,butm<lybeprepar..dforcondltionsatagivan <br />tiO'lCor">taj:1e. <br /> <br />" <br /> <br />26 <br /> <br />I <br />