<br />.;:. '.'i~
<br />.:.~~,#r.. .
<br />..:':':'~f
<br />,."'.....-
<br />:."-.
<br />
<br />ooa~ 70
<br />
<br />flooding will occur, and action
<br />Is necessary to warn the:pub1ic
<br />to evacuate potential flood
<br />areas.. .
<br />
<br />Mode 4: Flooding Is occurring; MARS ',.:lr.
<br />operations focus on dlsaster"~<
<br />management.
<br />
<br />5. FLOOO DETECTION OPERATioNS
<br />.,
<br />
<br />Under normal conditions (Mode 0), the'
<br />point for' receiving Information about potentIal
<br />flooding ~s the Boulder Regional Communications
<br />Center, the local public safety dispatching'
<br />agency. Its personnel are responsible for.
<br />Initiating flood detection operations by paging
<br />the appropriate personnel when established
<br />criteria are met. Triggering Information may be
<br />,In. the form.of NWS watches or warnings, more
<br />. detalled.messages from a private weather .
<br />service, observation of Intense storms on
<br />weather radar, 'field .'reports, "or 'alarms 'from the
<br />STORRM (Sheriff's Te1emetry'Operated Rainfall
<br />. and River Monitor) system alarm prograni, 'wh'lch
<br />wi11.be discussed In the next paper' presented.
<br />A monitor"dIs1playlng these alarms 15 located I,n
<br />the Communications Center; a1arms.may be
<br />Inltlated,;lly.',ralnfa11 rate or total amount,' as.
<br />we 11 as by: stream rate of rise ar. stream. leve 1.
<br />The'prlvate weather service 'provldes
<br />.preformatted advisory messages; free form update
<br />messages, and Interpretive dIScussions; . There .'
<br />are four'Rref~rmatted messages, called A,:B, C,
<br />. and O. :'Me~s~ges Q. and C'.are' roughly 'equivalent
<br />,to NWS watch~s ,and.warnlngs;,'respectlvely,but .
<br />are targeted. for a much smalle~ area. Message 0
<br />Is a cancellation of'prevlous'advlsorles.
<br />Message' A'-IS an, Internal notification' that
<br />conditions favor the development of severe
<br />storms later In the day. This message Is
<br />disseminated .to flood detectlon:personnel, but
<br />does not necessarily .trlgger a, Mode 1. ,,':It IS'
<br />typica11y:re1eased 15 to 30 times . each flood.
<br />season. . . ... '.'"
<br />Once thecOlllllunlcatlons center triggers
<br />a Mode ~,:..flood :detectlan operatlons:iare assumed.
<br />by the :S'tuatlon'Inforinatlar\"CeAt~~",,'~.I.sary: {
<br />notification Is .made,.to :Ol\"du~y supervIsory":'" ".'
<br />personnel'and"other'l(ey'1ndlvlduaTS;however;' .',
<br />......... signlficant:mobHliatlori.apart"f;;ointhe'SIC-'does'
<br />not begin unUl'Hade 2.', The pehonnel staffing'
<br />the Situation' Information Ceriter'arepr'edom~
<br />Inantly Boulder Shulff's6r'BoulderPolice'
<br />employees .tralned"ln flood'detectlon procedures.
<br />Technlc'aT 'asslstance'lS available frail" " ,.-
<br />englneers,.-hydrologists; and'cOlliputef..: ,:
<br />. specl a II sts' emplajed'iby"the'Ci ty ,pr'County.
<br />During Modes 1 and' 2,' the storm'ls .
<br />tracked on radar'; illrection ani:! rate"of movement.
<br />are determined and correlated with rainfall
<br />patterns 'Indicated by the'STORRM syStem.
<br />Rainfall averages' for .the last"3and"12 hour
<br />periods In the relevant portions of' six basins
<br />are dISplayed .on'. the 'STORRH 'Alarm Monitor. The
<br />STORRM system calculates the"approximate
<br />exceedance Interval as an aid to assessing the
<br />potential significance of the event. The
<br />program also projects the rainfall since the
<br />start of the event forward over 3 and 12 hour
<br />periods, again showing the 'assoclated exceedance
<br />Interval. STORRM monitors also display present
<br />stream flow at 12 gauging points. In addition,
<br />the computer prOQram provides an estimate of ..
<br />
<br />.' .
<br />
<br />::*~.
<br />
<br />:,~
<br />
<br />."~~
<br />
<br />... --'-. D. Van Wie I
<br />PaQe 3 I
<br />
<br />total' stream f1ow'whlch will result from the
<br />rain received to the present, as well as that
<br />which would result from the .projected rainfall.
<br />The program attaches exceedance Intervals to
<br />each of these estimates by reference to existing
<br />flood plain studies.:' . '. ". . .
<br />'.' '. '. Displays are maintained which enable
<br />each perspn to assimilate what is happening
<br />outside his or her,area of specialty. The
<br />:.Situatlon Officer produces regular updates on
<br />the probability of flooding, .Indlcatlng
<br />potential severity, time of onset, and ..',
<br />locations. He briefs the Facilitator', who.h
<br />responsible for disseminating Information and
<br />making changes In Hode status.
<br />. Hode 2 begins when the Facilitator .
<br />determines 'that. the threat of flooding Is great
<br />enough to warrant advisory notification to the
<br />publiC and mobilization of public safety
<br />agencies In preparation for the warning. This
<br />also al10ws.agencles.with .flood threatened
<br />facilities to make Internal preparations;
<br />During HOde,2,.the Facilitator directs
<br />publiC InfOrmation officers ,to: prepare messages
<br />.for dissemination .to the Public, and advises
<br />jurisdiction heads and' key"publlc officials.'
<br />Affected jurlsdictions'establlsh command posts
<br />to. manage .field operations.. and send command'
<br />post. representatives '.to the. Situation'
<br />Information Center.... '. . "
<br />Baseo.onconcensus-derlved from the'
<br />working'group In.theSltuatlon Information
<br />Center, 'the facilitator decldes if and' when to
<br />move to' 'IOde'3. The '.lnevit4ble,tradeoffs . .
<br />betlieeil'tlmeilness' anii"accuracy beconii! very'
<br />evi dent lit t~1s s.tage?'(l>eopie.ch~i:ge~ 'with
<br />llIlJllerient Ing ~the)'arnl ng :'pr9ce~ 5 , always :want a
<br />decision soaner ~han thosemonltorlng:t~e
<br />. situation are:wi11ing.to'make it;) . As: the . .
<br />system has 'dey'eloped 'over .the . last several .
<br />years; hoWever,'ft 'i5 apparent'that thh"tenslon
<br />can be' utlll'ted to :prodLici(decl.sjons'c1o~er. to .'
<br />the optimum than. either: group'.wo~ld. make alone.
<br />: The desig",and"de~e19pme~t'gf'::the , . '.
<br />Boulder County flash fl09d detection'.and"'warnlng."
<br />system. has been drlven.'by'p~bllc"safe~yri~~ds."
<br />Thesyst~ nl!" In'p1.acemeet~,thosen~~!(by ':'
<br />integra:thig 'pu,~llc 'safeJy',~~d 'hyi:!r~log!~al ,: :
<br />'declsloQ~mll~ing" tn"~_~~ngl~: 19c~t Iq~Ll'~ere, _~ ,:. ,__'"
<br />pers.'l~ner ~I~h~)ff~.e.~~ exper~lse~~4/~~::, .: .'.
<br />perspectlve~ ca,n Interact. ' ,,'..: -. .." .' ,
<br />. ..,SWRRM $ystSri:pr~grams have a'fded th1s .
<br />. process 'by :.eltmlnatlng detailed' data reduct,lon'
<br />tasks of .thesltuatlan mOnitors, alloWing them .
<br />to malnta,ln"a 'broa~er perspec~1ve onarap.ldly'
<br />changing prOblem. "Slml1ar!y,. theformat.of .'
<br />STORR,M outputs makes,lt easler'to":cciinnunicate
<br />thenatu're of Jhe::problE.i"to"pu~llc safety;. .
<br />personnek' A inore' detal1ed description' of' the'
<br />STORRMsystem arid Hs ~eiltral site 'programs '
<br />follows. ." . ....<. " .
<br />..."
<br />
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