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<br />FLOOD, lOO-YEAR <br /> <br />land is temporary. (2) The land is adjacent to and <br />inundated by overflow from a river or stream or an <br />ocean, lake or other body of standing water. <br />~ormally, a flood is considered as any te~porary rise <br />in streamflow or stage, but not the ponding of surface <br />~ater which results in significant adverse effects <br />in the ~icinity. Adverse effects may include damages <br />from overflow of land areas, temporary backwater <br />effects in sewers and local drainage channels, creation <br />of unsanitary conditions or other unfavorable situations <br />by deposition of ~aterials in stream channels during <br />flood recessions, use of groundwater coinc1detltwith <br />increased strea~flow and other problems. <br />A type of flood, including the water surface elevation <br />dlluterriturialoccupationthereof,whichcanbeex_ <br />pected to occur at any time in a given area basec <br />upon recorded historical precipitation and other valid <br />,"atd, uulwilh an average statistical one percent <br />chance ot belng equalled or exc~~ded during any on~ <br />year. Th~ terrr. is used int~rchangeably with 11: ch"nc~ <br />flood or Intermediate Regional Flood. <br /> <br />flOOD STAGE <br /> <br />LEFTS,,:IK <br /> <br />DSSTRUCT10N <br /> <br />?EAK DISCHARGE <br /> <br />PRU3AS1LITY <br /> <br />FLOOD CREST <br /> <br />The r:1dxbum <;~age or elevation reached b,y the water <br />of a flood Jt J giv~n location. <br /> <br />FLOODFREQUEr,CY <br /> <br />{See Probab11 i ty) Tile averag~ recurr~nce inter',al of <br />spccificdischarges ill" water stages whicncd,e flOMing, <br /> <br />REACH <br /> <br />FLOOu?EA\ <br /> <br />The ma~imu~ instantJneooS discharge of a flood at a <br />gIven location. It usually occur> at or ne,)r the tim~ <br />of the flood crest. <br /> <br />RtCllRRE~CI: lNTERVAI. <br /> <br />FLOQUPLA1N <br /> <br />REFERENCE POINT <br /> <br />IIn area in and iJdjacer.t tOa stre.:mwhich is subject <br />to flooding ", a "e;ultuf the occurrence of a 100- <br />Year Flood. Thus it is so advers~ to past, current, <br />or fore~eeable co~struction or land use as to constitutQ <br />a significant haZard to publ ic health and s~fety or to <br />property. <br />A graph snowi~g the relationship of water surface <br />elevation to locat iJJn, th~ latter genera 1 \y expressed <br />as a distance above the nouth for a stredn of wdter <br />flowing in an ope~ channel. It is generally drawn to <br />show the surface elevation for the crest of a specific <br />floDd, but m~y be prepJred for the CQ"dit ions "l d <br />giventicleorsta',;e. <br /> <br />:<IGHTS"rJK <br /> <br />RU~j()F F <br /> <br />Fi.uuU ~kLlf lL~ <br /> <br />STREAM <br /> <br />'^',~TEfiSrl~~ <br /> <br />" <br /> <br />The stage or elevJtion Jt Which ov~rf1ow Of the <br />natur~l banks of a stream or body of water begins <br />in the reach or Jrea in which the elev~tion is <br />meiJsured. <br /> <br />The ban~ on the left side of a river, stream, or <br />water course iJS the observer looks downstream, <br /> <br />Any natural or mdnmJde object existing in, along, <br />across, or projecting into any cnanr.el, water course, <br />or regulatory flOOd hJzard area which r:1ay impede, ~~. <br />t~rd, or change the depth or the direction of flow <br />of water either by itself or by catching or collecting <br />debris carried by such ~ater, or tilat is placed ~here <br />the flow of the water might c~rry the same downstream <br />to the damdge of life or prop~rty. <br /> <br />The 1 arg.os t val u e of s treamfl ow at t a i ned by d f1 o~)d , <br />usually reoorted in unib of ctJbic hl't pl'r secDn(j ,cfs). <br /> <br />The Jnnual chance of occurre~ce of specific hydrologic <br />events, such as rainfrlll over a specifie;i area or peok <br />di,charge at ,) s~ecified location. It is expressed in <br />percent, ~,g.. 51.: re~res~nting one chance in 20 of the <br />event occurring in any yea" or an averoCle rec~rrence <br />of once in twentyye2rs. <br /> <br />A seg~ent of the river defi~~d b~tw~en t~o specified <br />poir.ts. <br /> <br />rr~ )v~rJge il1te~'!~l of t.ic:e, 1~ ,year:;, '.,'i~11~" "hich <br />rl 9 i v e n flood ,",' ill b e f~ x c e e d e (t 0 n (. e . <br />A numbered point identifyin~ a specific location for <br />correlatinq the drlta shown in vanous fo,'",s U,rou~h_ <br />Out th~ re~()rt. <br /> <br />Tlie brlnk on the ri ght ~ ide of a r1v~r, .tream, cr <br />o'Iater course, lOr)kin~ do',mstreac,. <br /> <br />TI>", quantity Of ~a;~fdll \<~ic~ flc:'.,'~ O'icr t;;c :;"rf~,~ <br />to enter the streJ~ as discharge volume. The dif_ <br />ference in quantity between rainfall and runoff re~- <br />resents 10sse, to infiltration and interc.:ption. <br /> <br />Any natural channel or depression tnrou<jh which water <br />flaws ei tiler cont jnuo~sly, interrni ttent1y cr periodi_ <br />cally, includir:g any artif icial ~odifi cation of the <br />natural chdlll1el crdepressiiJr.. <br /> <br />The drJinage al.ea situated abov~ J sp~cif ied ~oint on <br />a stream including tne area drd1ned by tributory str~o"1S <br />w~ich ent~r the mai~ streJ~ above this point. <br /> <br />,0 <br />