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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 flood 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 lass <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 stage or elevation reached 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 looklno Jownstroam, <br /> <br />I'I00d PI'lln <br />The relatively flat are~ Or low land5 adjoIning the <br />channel of a river, stream, watercoursoorocean, lakaorothar <br />body of standing water, whIch has been or may b~ covered by <br />fIOOdw",ter. <br /> <br />I O-Year , 50-Year, 100-Year, SOO-Year FlOOd <br />A flood having a 10, 2, I, and ,2 percent probabilIty, <br />r~spec+lvely. of occ~rrenCe in any Y01lr or an averaqe frequency of <br />occurrence In the order of Once In 10, 50, 100, and 500 years, <br />respectively, Tholloodmayoccurlnanyyear. Itlsbas"don <br />statlstlca; anaiysls of str~~"I;ow r~cords end analysis of rain- <br />fall an1 runoff characteristics In the cenoral region of the <br />waterShAd, <br /> <br />FloO<JProfll.. <br />A graph showIng the relationshIp ot water surface ele- <br />vation to location, the latter generally expressed as distance <br />above mouth for a stream of water f lowing In an open channel, It <br />Is oener",lly dr1lwn to show surfllceelevatlon forthecrestofa <br />speciflcflood,butmaybeprepar..dforcondltionsatagivan <br />tIO'lCor">taj:1e, <br /> <br />" <br /> <br />26 <br /> <br />I <br />