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<br />GUIDELINES FOR FLOOD PLAIN MANAG~~ENT
<br />
<br />aypothetical examples of these presentations, depicting the areal
<br />limits and elevations of the respective future floods at an imaginary
<br />location, are shown on the following page.
<br />The lateral limits of flooding from the Intermediate
<br />Regional Flood (IRY) are shown by the blue-shaded area, while the
<br />solid blue area indicates the ad1itional area that would be under
<br />water from the Standard Project Flood (SPF). The flood profile
<br />shows the relative depth of floodwaters along the centerline of the
<br />stream. '.l'hecrossseotionex,,",pleindicatesthedepthandlateral
<br />extent of flooding that would occur at the specified cross section,
<br />other inforrnationon flood. flow depths at the locatio:oof the cross
<br />section is tabulated below. Similar data call be developed for any
<br />flood plain location in ,..- ~~..~" -.. '"~" ,
<br />U", ~4""'" Leac" cons~uer=-, ~n this report.
<br />
<br />Man has been building on and occupying the flood plains
<br />of rivers and smaller streams since the arrival of the pioneer
<br />settlers. The streams first provided transportQtion Qnd water supply
<br />and "'t a later time their usually gentle valley grades encouraged
<br />the construction of highways and railroads: Today, the continuing
<br />growth ot cities and urban sprawl re~ults in ever increasing en~
<br />croachment on the stream flood plains.
<br />Through bitter experience, man has learned that floods
<br />periodicallY inundate portions of the flood plain, damaging property
<br />and often ~ausing loss of life. Vast surns of money and material
<br />resources have been expended for structural flood control projects
<br />dams and reservoirs, levees, channel improv~nts, and similar pro-
<br />tective work _ designed to secure man's habitat against the force
<br />of nature's floods. Unfortunately, however, encroachment on the flood
<br />plains has taken place faster than control structures have been built
<br />and costly flood d~~~ges have continu...d to increase across the nation.
<br />
<br />EXA.'1PLE OSE OF FLOOD PLAIN INFORMATION
<br />
<br />UXATIOO
<br />
<br />DISTA.VCEFROM
<br />STRI"MCEN'l'ERLlm:
<br />
<br />DEPTIlOF
<br />,~
<br />
<br />FLOODWATER
<br />'"
<br />
<br />Feet
<br />
<br />F~et
<br />
<br />This increase has led to a new approach for reducinq flOod damages.
<br />,
<br />Called "flood plainmani!.g_ent." this new approach consists of
<br />applying controls over the use of flOod prolle land prior to construction
<br />or uSe of the land.
<br />
<br />point A
<br />
<br />PointE
<br />
<br />;c
<br />>>,
<br />'"
<br />
<br />u
<br />'-'
<br />
<br />u
<br />U
<br />LO
<br />
<br />PointC
<br />
<br />,",ntrl..""". nIl variQus flood plain manag'-"'\ent techniques
<br />that can be adopted in a realistic flood damage reduction progr~ io
<br />presented in tllto followinq text. However, speCific recommendations
<br />for implementing any ~rticular technique are not prov\1ed ~s such
<br />optIon generally r~main~ t~ responsibility of local community, county,
<br />or 8tat.. gov..rninq ,'g('nci..~.
<br />
<br />ay u.~in'J inform,,~ion "-5 ill,,~trated ate"c, to<;cther 'o"ith
<br />other cata such as fr<>qucmcy of occurrence, velocity of flow, an1
<br />dL:iJcat:io:l l! LClod:.nC", "QnCErn"(~ 'rld.ividuals can mak", khOwled<J"Qble.
<br />decisic"", ~dative to ':::,~ "'"~. '~HA'^""'~ ~~. c
<br />~_~ "',"~~v..-~."n" arl" ",.."agem"nt o. ~,~"s
<br />"ubj,.",~ c,," -,n'm<;!IlUo!": by ~l=d '.'''-tcrs.
<br />
<br />Interpretation of Data
<br />Flooded aren maps, prOfil"", an~ ~,.l..~t..cl ,"ro~s "...cot.ions
<br />~re provided in t~e r~i'''rr to rl~fine thA lim;t~ of flOOding that wo~ld
<br />QCC\lr during J," Intomedi"tc Region<\l Flood N Stdnddrd Project Flood.
<br />
<br />Zoning
<br />
<br />S~I.~ctJ.v~ ~Qning constitutes a legal tool that c~n be
<br />usee to imple"ent ar~ ~nforce t~e detail~d plans r~sulting from a
<br />land ua" pla,mir." ptoqram and ensures the mo~t b..neficial us" o~
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