|
<br />suppli"d by ~he ;;\;5 .."eh d"y. An audIovisual ~lan, "HI be activated
<br />wh"n the hyd~ologie model predicts certain at ream d1,charge conditIons.
<br />The coot <act cost of thesynemiS nbout$ZoO,OOO. Theco""",nityls:ln
<br />a ;>"p"lar resort area. VlsHors aN transient,." petl"dte testing of
<br />the ay~te", h limited tD local <>fftdah atlJ bust"".. eatabl1shlllcnts.(2))
<br />
<br />unable to do because of a" In~uf Hclent ataf f. The cooperat 1 ve
<br />);'.S-pdvate con.ult"nt Ilrrangel1le"t ha. worked we 11 In ~he Denver
<br />, (13), (20)
<br />r..goIl.
<br />
<br />Agen"ral flash floodw"rning system has been eotablhhed for the
<br />Denver metropolitan area by the Urban Drainage and flood Control
<br />District (UDFCD), a dx-county regional "gency. Since 1976 the UDFCD
<br />has been active in the area of flash flood "'a'tnlog. The geneul flaoh
<br />flood warning syste;n involves iillproved radar capsbllHy for the region
<br />and the e"'ploy"",nt of aprlvate "",teorol<>giC servIce toasslsttheCl '.'5.
<br />Within the general..."rning region, indiVidual b".io\u'tning plans ar"
<br />being formulated. It is noted that in order to receive Hnllncial
<br />as.i.tance fro~ the l~FCD, local intere.ts must agree to illaIntain the
<br />
<br />AS /I ~art of the general Denver [t.~sh flood ""rning "y.te.., a
<br />ba~in flood warning SystCill "as developed for ~he ao~lder Creek basin,
<br />north"estofDenver. The has in is so"",,,hat s1:lltlar to the upper
<br />Ca~he la Poudre RIver b.~sin. Do the basis of proddIng longer lead
<br />time, reliability, and credibility, a cOillbination of automatic and
<br />:nanualraingagesandautomaticand",anualstrelU'gage.""srecom-
<br />;nendftd. A network of 6 r"dlo raLn gages, 3 radio strea;n gages, 60
<br />volunteer rain gages, 4 volunteer stream gages, and 13 radIos for
<br />volunteers "as estimated to CQat $160,000 ",ith an a~nual maIntenance
<br />(24)
<br />co..t of $14,000 at 1977 price leve18,
<br />
<br />",arnIngsyHem, regulat.,flood plalne, and have a cOlllplete warning
<br />plan.
<br />
<br />The Boulder fla.h flood warning system "as installed in 1979,
<br />excep~ for the ..uto"",ti~ atream gages "",ien ...ere Installed In 1980.
<br />Thecurr..ntsystemhaseIghtautolllattcraingsgesandthrceautomatIc
<br />sttea~ gages, tn addttion to volunteer components.
<br />
<br />To improve rad..t capability, the UDFCD purc""."e" ~ol"r radar
<br />receivers for the ."'.'5 and the private ..eter010gical setvice; they no...
<br />hava immedLate aCCeSS Co "cather rad..r LlMge~ from the nearest :'WS
<br />...eath",r radarsat:"l""n, Col<>rado, and Chey.>nne. Wyollllng. Previously,
<br />the Denv~r l'1W5 o,Hce reCeIved only tnfedot quslity facsimile i""'ge.
<br />!romLilllonandnoll1klgcafromCheyenne. The privatc "'eteorological
<br />s~rvice C"n issue Inte~nal alerts when it determines they $re needed.
<br />Intern,'l alerts notify offt~1ah and ar~ not trans",ltted to the g~"eral
<br />public. Th~ prLoate .crvice dnd ohe :'WS joLntly pru~are 11".11. floo"
<br />potenthl tor"ca.ts. The N'.'S L'8ue~ the public W'arning.. ,he private
<br />
<br />In the Boulder .lrea, prediction of the flash flood har.ard is
<br />, . ~ . ,."'~ of atr~am de~thA ..od "hat the$e ""an a~
<br />pr~~~"t y ,~.~" ~n~, ~
<br />do",nstream poInts. Curves or tables Ruppll"d by the :-<WS do not ade-
<br />quately define the relationshIp bet...een raInfall and runoff. The :-<WS
<br />data is used to selectively activate the volunteer network, based on
<br />rainfall. Studiea are underway to relate has in runoff to rainfall.
<br />When this has been deterllllned, it is e.;:pected that a minlcOlllputer,
<br />"h1chhasbeeninstal1ed,wUll>eabletoproducereal-U"",hydro-
<br />graphS. A data rece.lver, printer, and eiectronLc ""p display inco",in.o;
<br />data. The "inlco~~uter can also record and dIsplay incolllI~g dats.
<br />.'Hh new soft"'"re, It ...ill bc able to <'Miyze the data tiS well. Fa'!'
<br />redund"ncy, fiood "a<<>lor, f <lC I Ii tie; "re loc.'ted ho~h dt tile Soulder
<br />COClnty l';l~l1c Works !)cp.,rt01en< a<\d .H the $he~!f['" of[Lc~. Th,
<br />
<br />~ervice relaya th~.~~ "..rni~gs i~ ~t"nd."~ fo~",.at ~a "".~ loc,,~~or:. tn
<br />
<br />,,"ch coonty; Intcrpretive guidance on the ~~S "e~"age Is also provided.
<br />Fro", the COtmty level, ~h" ""'ss.~g"" "fan out" to ea~h to~'_~. The
<br />priV'ite "ervjc~ lMndtes " lot of 1(}c,,1 co",=~LC"tio~ tll"t the l<WS 10
<br />
<br />~'J
<br />
<br />"
<br />
|