|
<br />and paget sh,mld be located {n the Spencer Helghts <lre~. The estimated
<br />mini"'"m cust for addtng da:n failure dete~tion is gtven in t<l~le 19.
<br />This ~os~ Is sepnate frolll th" costs <.l.ed in the analysis of flash
<br />ftood d~te~t{on systems.
<br />
<br />",eathcr in other pliers of Colorado. Volunteer repons received might
<br />also be Inaufflc1ent to predlct severity of flooding.
<br />
<br />INITIAL SCREENI~
<br />
<br />First Cost
<br />~utomati~ $trea:n gage.
<br />Repeat~r stlltio"s
<br />l'olceradio
<br />
<br />$10,000
<br />14,000
<br />1,250
<br />
<br />Thefll1ni..um_scalealternativeol,2,and3",ouldbeanilllprovement
<br />over the existing sttua~ion. The cost analysis indi~ate~ that ~o
<br />achieve at least a ",orthwhile degree of detect ton, as represented by
<br />these aiternattveo, an investme"t of obou~ half of that for th" inter-
<br />mediate-level alternotiveo would be required, Ho",ever, a some"'hat
<br />greater n"mlx'r of sensors would be destra!:lle and the minimum-scale
<br />altern8ttves would not provide a redundant mean~ of da~1I ~ollectton,
<br />
<br />Table 19
<br />E~~imated Cost
<br />Of Dam Failure 3nd Sno"'m~lt Detection
<br />
<br />Itelll
<br />
<br />Amount
<br />
<br />Total cost w/25% contingencies
<br />
<br />$30,000
<br />
<br />The ba8in-scaie flash flood detecrion alt~rnatives are 7, 8, 9,
<br />10, 11, and 12. These are single-component <llternatives and provide no
<br />redundancy. Also, coverage of the upper North Fork bllsln "'auld be
<br />excessive as thc North Fork runoff is relatively slo", snd the area is
<br />sparsely populated. Alternative II, with <I color radar receiver at
<br />FortCol1ins, whllehelpful,\I'Ouldnot be indepe.ndent of theNWSradar
<br />andwauld, Cherefore, nor provtd.. backup. Ground eonfir,""tion of the
<br />fainfail indicated by radar \oiould also be needed. Alternative 12
<br />iovolvesemployingaprivate..etcorologlclllcoosultenr. Theoddsofa
<br />success fill forecast might be i"'l'roved Ix'cause a consultant COllldfo euB
<br />on the specific area of concern to a client; the ~WS forecaster~ are
<br /><esponolblefor29countiesinColorado. For examp1e, during the 1979
<br />cooperstive flood warning program at Denver, on 13 of 16 significsnt
<br />flash flood potent tat days, severe "'eat her in parts of Colorado away
<br />fro," the n"nver area dern<lnded "'arning action by ~WS foreeasters.(22)
<br />
<br />Total first cou
<br />
<br />$25,250
<br />
<br />Ope rat ton and ~iatenance
<br />Operation, ~aintenance and rep1ace~nt
<br />
<br />$ 1,240
<br />$1,900
<br />
<br />EVALUATION
<br />
<br />,~s stated previous ly, t!1e obJective of the f iash f load detcc~ion
<br />alte~natlve6 13 to provide as """ch lead time as posstbl~ at as 10", a
<br />cosraspossible, consistentwithper!ormance.
<br />
<br />It is expected that the NUS forecasting system "'111 detect most
<br />flood producing condttions. The :laoh :104d detect ton alternatives
<br />should provide a ba~kup to the 1",,5. b. order to dQ this, "n alterna-
<br />tive shollld provtde Larl",er County officials wtth " positiv~ ",..r"ing of
<br />flash fioods tn the absence of ~W5 rad<lr, or a forecait fro," the NWS or
<br />the private ~'oather consultant, S"ch a situation could arise if a
<br />localtzed f3s:-forming stor," occurred ~hen the Cheyenne radar happened
<br />to b<- tllrn~d off; th~ "iillon 'Ad... [s coo ,,,r a\JAY to d~te::t $uc'\ an
<br />"."ent prup"rly, ~~~S penonn"l <:o<.lld ..tso be oec\lpied "'~th SeVere
<br />
<br />r,,~ prha.e for"c".t~ shO'"ld bc ~"ot'd~r.,,::,,<! "'ith tl;e ~"(;S. 1l0"".v~r, r,,~
<br />fl"sh flood detection alteraatlves, to provide redundancy, shOll1:igive
<br />w"rning t"dependent of fo[eca~ts.
<br />
<br />1h,' [nl~r"",,~[at~-s~,~le alt..rn",I-"~A "ho..." ,1" pl~te5 13 thr'>Ui\:' IS
<br />"er..",'l.c<eJfo(f\Jrthereval\Jatlon.
<br />
<br />"
<br />
<br />%
<br />
|