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<br />Since these detentior fdcilil1Cs '..-ere not cte,igneoas f1oodcontrol facilities,and
<br />do not provide emergency r{!1 ief through spi 11~'dYS in the e_ent of ) arge floods, this
<br />Jl temative is very d~sireable fro'll the standpoint of publiG safety. 'ilhi le the
<br />benefit:cost ratioofthi,; project isverypoor,ilcostq\lantifyingthevalueof
<br />p~bl ic safety is nat illcl uded, d"d wuulr: serVE t~ inprove the econmr.ic teas illi1 ity
<br />of >l!~h i\ projec~. Tile va lue of publ ic sdfety iwre <;oul d only U'" es tin", led through
<br />hrtner detdiled study \"Ihich would investigate the probability of ernbilnk,,,ent fail-
<br />ures r~rticul arly at the Co ]ofado and So,)thern R<li] road near Collp.yp. Avenue.
<br />
<br />A1tern~tiv" r4
<br />Alternative #4 again alleviates all flooding of exi,ting stru~tures during th" 100-
<br />yedrevent. A detention facility at Moore Pilrkwould repldce existing detent ion
<br />behind Taft H111 Road i!nd the Colorado & Southern Railroad near College Avenue.
<br />The benefit:cost ratio for this total project is 0.55 and Iwt benefits are negati'le,
<br />
<br />Thisplanessential1yprovidesthesamebenefitSdsAlternative#2,andelil'linates
<br />concerns for public safety arising from use of existing detention b ehindroadways
<br />and railroads.
<br />
<br />Alternative ~3
<br />Thi s d lternat ive plan C(}ns i sts af channel irlprovement~ to cont8in the lOO-year event
<br />for full develop"-l'nt conditions ,,,,itil existing detentior. at Taft Hill dndtheColor8-
<br />,~() g Southe'lI R~ijrOdd Hl'dr Colle~~' Ave,\u,". The b,'nefH:cost ratio of thi~ ph" is
<br />1.04 and net be'lCfig ilre ap.proxi'"dely 5174,000 'or the total pr.oj(~ct.
<br />
<br />Alternative#S
<br />This improvemei1t plan is a corrbinHion of Alternative jll andAlternativei!2. The
<br />plan addresses channel izotion improvements in areas of hj~h dalrldge ~otentiill, dnd
<br />floodpJain manilgement in area,wher€ damages are limited.
<br />
<br />This plcln, while re!1lJvinQ all exhting s~r'jctures froIT: the flcodplain does not
<br />ac[Oullt for tl',~ sdf~ty of ~etcntion behind "O<lco"/~y ~ild rJ1lroJd emc'JnloTler,ts. The
<br />~IM, ',iOule! ,'cljIJirf' that ~I\i'\f' ~^i<;l.in9 f'III!,,;nk'nf'nt<; Dt' ~erp"tLJ"t~o <Inri ,,,,,int..linp.o.
<br />!lO','€Ver, ir;pr()v".'f'llts tn p,"brlnk"IeI;L~ t() ~pn'''' ,,~ f10nd control fitrj 1 i t ;p'; wuuld
<br />1 abel these em~ankll:ent> as GallS that s~ould be ,;ubject to the r-=gu lations of any
<br />in1po~nd:.lent a5 re'1',Ji).~o by th~ Co lorado State Engineer's Office.
<br />
<br />Thebenefit:costratioforAlternativeii5 is J,97 w1th nl:t benefits of approximately
<br />SJ,190,OOO.
<br />
<br />Th is p Ian ~,es the undeta ined 100- yedr fl ood event as the bas i s for floodp 1 ~ in man-
<br />agew"nt ~nd fnr drs';qn improveml'nt\. The pl~n dn~s nnt call for imnediate Y'etXlval
<br />of existing dt>tentionbenind roadway and ra11roadEillDdnkr,ents until inlprovE"l'l€nts
<br />jown<;treJw.JreiITIplemel1tedtocontail1thc5i'flo'1-/5.
<br />
<br />r!l~", i:qlrnWI"pn:,,, ',.m,,11 QC""nt Iy inrrp3'"" th"" rr>,t (11' th;, ~I tPrrlnt1 VI'- nnrl wr>"lrl
<br />re',:uve it from ~ons ider"tiQr ,15 ,In eUlr.c~i ca 11y fcasiJlc alterf!a;;jve. '"ithout
<br />these 5'J 'ety ilT'prove,"~n ts, tht' <,1 tl'rnal i Vi' S i>ou 1 d mt be ":lP 1e",el., ted wi [holl~ du<:
<br />cO:ls1cerdtiQ': to putl i, qfet,' belm'.' tilese ell:!Jdnkuents. Thi~ "dJ(' co~s.idet'dtion"
<br />,~: I)! d i n,t: ~di' il: J '"i'l i nl'n J~ ev~ I L,,; t i on c f the> '. tabi Ii tv n t :hesc \'II1JJnb:i'I>:s. an 0
<br />,''' <"irlj ',,'dril i'Lg ,,/5tel;; to eVdc~atc res den ~~ in the evellt of :; igJl Hi C<lr;t ;.;,"'diILg
<br />be~ i ~d tr,rse 1'1"~,ilnk,,..nt<;.
<br />
<br />Thi~ al tErtldt ive doe, reconl:le"d dfl eval\Jdt io" of the ,afety of tllese embanklT1€nts
<br />befo~ the plan is adoptee, and furner rewmr;1ends thot a flood warning system br
<br />
<br />il"ple"""ltCd,:rl>ils\lchtilr!:'detention l$re'l'()v",d.
<br />
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<br />-62-
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