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<br />Flood Profile. .". graph sho'o/i<lg tlw_ relationship of 'oIi.te-r surface ,,-l~vation to
<br />location; the latt~r generally expressed 33 dtstance above moueh for a r,trearn
<br />of water flol<lng tn an open channel. rt is gcneraHy draWll eo sho",sutface
<br />elevation for the crest of a specific flcod or flood f~equency. b~t w~y be pr~~
<br />pared for conditions ut a given time or stage.
<br />
<br />R1;;htBank. The ba"kon the r1ghe sideofa river
<br />lookingdownstreaOJ. '
<br />
<br />str~am. o~ watercourse
<br />.
<br />
<br />Stream. Any natural Cho.."lnelordepreSSi'>l1 tht"<)ugh which wat fl i
<br />conUnuoudy, intenoitte"tl' o~ 10 . er 0""' ether
<br />fiea.t:l.on of the natura' _h02:., pe~ dic&lly. :rndtlding any artificial Olodi_
<br />. ~ ~'''c~ o~ "Cpression.
<br />
<br />Flood Protection Level.
<br />elevation for r~gulatin~
<br />
<br />A l.we1
<br />u6<,sin
<br />
<br />which h ""tablis",,d
<br />high ha~ard areas.
<br />
<br />ahove ~he lOO~year flood
<br />
<br />Ten-Year flood A f1 d L
<br />. 00 "",,ving an average frequen<:y of O<:C\lrren~" on ~he
<br />orderoIonce in ten Y"drs although the f1=dma. oc .
<br />successive. years. It is based on s~at's.'".' y Cur in any year o:r even 1.n
<br />i' .., ~ '".~ ~ analyse-s of stre"",f1o" records
<br />"va ~au~e- for the watershe.d and analyses f
<br />in tho ge.neul :region of the watershed. 0 ra1tl.fall and runoff e1\a:ra<:te:risti~s
<br />Underclea.rance. The l,,"est point 01 a b i~- ..
<br />"i L r ",," Or Qtue.r Structure
<br />r vel', s~rea~, or watercourse that l~its the. openings th h
<br />f1o'",... This is referred tc> as "low s~eel" in some ....gions. roug
<br />
<br />c>ver or acrc:>ss
<br />wbichltatu
<br />
<br />,Lood Stage. The stage or elevation at ~hich overflow of ~he natural banks of
<br />a stream or body of ",ater begins in the reach Ot areas in ",hieh ~he elevation
<br />is "easured.
<br />
<br />now Line. The minimu", stllge Or elevation at whic.h flo..' occurs in a stream.
<br />
<br />Head Loss. The effect of obsn-u~tions, s\l<:h as nuno..' b:tidg.e ope.nings, Or
<br />buildings that limit ehe arca chrough which water must flow, raising the su:r~
<br />face of the waee.r upst~ea~ fro~ the obstructions.
<br />
<br />'.atershed.
<br />or!;'"sin.
<br />
<br />,,"
<br />
<br />contdbutin,draina&e.__..__ if
<br />~ ~c uvve '" spec ad point on 1I stre"",
<br />
<br />Left Bank. The bank on the left side of a river, stream, or watercourse,
<br />1o~king do'~strearn.
<br />
<br />Low HB~ard Zonc-. That ,neu of th" de.dgnllted flood plain in which ~he "'a~er8
<br />of an Interrn~dL8te Regional (IOO_Year) flood will not attain a ~a~imum depth
<br />grGae~r ~han one and one_half feet.
<br />
<br />W'" St....l. S.,,, "Und.,~cleara:\<:"."
<br />
<br />ObsCtuction. An,'dllnl,wlIll,whllrf,,,,,,bank.'t\ent, Levee,dil<e, plle,nbutIlleT'.t,
<br />prOject-ion, ",.cavation, channel rectification, bridge, <:ond<.llt. culvert, bu~ld-
<br />ing, ,,'ire, fence, rock, gravel, refuse, fill, str.~cture or o~her matter, in,
<br />along, across, or projecting in~o a channeL, watercourse, or ragu1atory flood
<br />ha7.ard area ",hieh may 11:lpede, retard, or change the direct ion of ~he flo;,' of
<br />water, either in itself or by catching or colle~tin~ debris carried bv such water.
<br />or that is pla~..d where the flow of the ""leer might ~arry the ~"me downstre"m to
<br />the damage of life or prcpercy. .An artificial obstruc~ion shall m~an any
<br />c>b"t:ruction which is not" natural obsttiicti:in.--ii-nat1JriiI obstruction shall
<br />meSn any rock, tree, gravel, or other matter tha~ his-heen Iocated-by-~ non_
<br />human cause.
<br />
<br />O<le~Hundred_Y"-ar Flood. A flood having >In aVH"p;e fr~qu"n"y of Oc,urr"ncp on
<br />th" order of on~e in 100 yc,,~s although th" flOQd ",ay occu," ill atly ).ear or eve"
<br />in succe"sive ye~rs. rt is based on statistical analyg~s of s~reamflow records
<br />availahle for ~he water"h~d and analyses of rainfall and runoff characteristics
<br />in the general region of ~he wat~rshed; sQmet1me~ called the Inter~ediat~
<br />Rey'i~nal Flood.
<br />
<br />~. .". Longin1dinal s~_gme.[\t of a sn~.a," or river. A reach wHl gen",.~t1y
<br />tn,lude che se~m~nt 0: the flc:>o<l h~~ar~ ~r~~ wher~ flood hcigh~s ~rc influencc~
<br />by ~ "'an-",~de ~~ r.n~ural obstrc,ction. ln ,m urban a~~.n, :he ~eg1T\Cnt of a
<br />stream ~r river bct"",,cn 1.wo ~,ons~cutiv,. bridge_ c..og,Ji,\~~ ..""Ie typica.t1y C":l~
<br />s~i~c~c a r~ach.
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