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<br />Su~~
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<br />flo~ (gene~al1y 100-year frequency) wi~h a specified increase in water
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<br />Englneertng field surveys for "..,,"tleat .1nd horhont"l (_ontr01 '...ere
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<br />surface elevations. The procedun~ is based on the equal conveyance
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<br />condu<:ted by Davis EngineeringSer"lces, [nc., 517 Spru"-e St,eet, Box 130,
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<br />reduction concept; however, the program does not allow encroach~ent or
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<br />Del None, Colorado. Held surveys ""re ","cdcd for additional "",pplng and
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<br />narro"ingof the channel. Input data to this program Include: cross-
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<br />crO$S eeetlon data preparedesl'ecially fOI" the hydraullr studies t nthis
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<br />section information in the sa~e format as water surface profile program
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<br />report. funds for the f1eldsll(veys, addttlo=l mapping and crOS$ sections
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<br />WSP-2 and elevations of the selected flow at each cross-section ~ithout a
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<br />~"re provIded by, and contra~.ted through the Calorado Water Conservat1an
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<br />floodway (from WSP-2 analysis). A basic assumption in thIs analysis Is that
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<br />lIoard. This wark Was cO\llpleted in the fall Dr 19711 and ~"l'pl......nred wah
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<br />rhanges in velocHy head resulting frornmodHiedwatersurface elevations is
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<br />additional infot'Olat1on by Davis Engineer1ng Services, Inc. in 1979. The
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<br />negligible, or in other words, the friction slope re~ins essentially the
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<br />surveys were tied into the origInal mapping and the ~aIs for vertical and
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<br />BIIIQC.
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<br />horhontlll control are described in the legend of "fload Hazard Area Maps",
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<br />A table of floadway ~idths vs changes in strea~ stage 1s included in
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<br />sheets 1 through 12.
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<br />Appl.'ndixlI,separatetothe"",inreport."
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<br />flood Plain Values
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<br />Maps
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<br />The assessments of natural and flood plain values ""re "",de as
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<br />Watershed And dr"in"e~ ar,," maps were developed from U.S. Gealoglc&l
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<br />follow.:
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<br />topographic map. (scale 1:62,500). Flood hazard areas arc plotted on
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<br />1. On-aLte Lnvest1gat1on by MdIe W. !1ustard. Stste BioLogist. sou
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<br />photogr"""""tric"",ps. Topographyandplani<netrywerecollll'lledbyphotogralll_
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<br />Cons~rvatlon S"rvLee. Denver. Colorado.
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<br />",,,tric lIlethods fr= low level aerial photography taken June 18. 1975. The
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<br />2. Farml.andsinthestudyareaareillll'artant. hOlolevcr,theyarenat
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<br />photogr,,",,"ctry is by l1errick and Co., EngineersandArchttects,l0855E.
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<br />classified as "PrImc". Info.m.~tlon regardl~ I'd"", Fan.lands was
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<br />Bethany Drtve, Denver, Colorada80232. Funds for themappIog1o'ere provIded
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<br />obtaIned from the map: "Important Fatllllandsof RioGrandeConnty,
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<br />by Rio Graod~ County tlod the Color:ldo Water Conservation Board. The ortg-
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<br />('-:-lotcb" ~t""3tC:! h;'
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<br />lten'_~A" ('~~e^~',".'~"
<br />___.. y~.. ~w..v_. .__.w..
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<br />SCt.~cc 3n:! Co13r~o State
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<br />inal.,"pping1o'as ona scale of 1"-IOO'andrcducedtoa aetlleof I". 200'
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<br />UnIversity Experiment ~tatton, 1979.
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<br />farworklllllps. The workm"ps '"'ere reduced to 1". 400' for report purposes.
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<br />5per.IfLc criteria uscd to identify PrIme Farmlands can be found in
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<br />Contour Interval is 2 feet and the datUl:lis ",,,an sea level. Themaptopo-
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<br />Publlr Law 95-97 SectIon 657.5; publIshed in the Federal RegIster on
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<br />graphytomplIe8101ith MtLonal rnapnccuracystandarda. l1"pmylarsonnscnle
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<br />Jan,".ry31,1978.
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<br />cf 1" - ~C:C:', "".: ;;...-.""y l"r,,,,"d,,,, ."" <H' ill" lie Lh~ lA>lorllao WilLer
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<br />Elevation Referen~e Marks
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<br />Conservat10n 80ard, 823 Stllt~ Cent~nn{al Bldg., 1313 She~"'~n St., Denver,
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<br />The "rlglMI b.,." nupping uMd for thIs flood h,,'.ard study 1oI,,~ "dll!>l,'d
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<br />Colorado 80203, telephone (303) 839-3441.
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<br />from topo;;r"pbLc ""'ps ",ade especillily tot devdop"ent plannilll\ Ln 1975.
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<br />AP-6
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<br />AP-S
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