FLOOD04753

• County: Jefferson
• Community: Jefferson County
• Stream Name: Bear Creek
• Basin: South Platte
• Title: Special Floodplain Information Report
• Date: 12/1/1972
• Prepared For: Denver
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

Bear Creek Is crossed by 7 highway and street bridges. The profiles
end reference table show that the bridge crossings sometimes create ob-
structions to 1100d flows. flood stages upstream of the bridges would
be oven higher If debris were to catch on the bridges and block the flow
erea. The flood elevations shown In this report were besed upon the
bridges remaining open. Buildings, fences end other structures In the
1100d plein elso obstruct flood flows.
The eree covered by the Intermediate Reglonel Flood varies In width
from 500 feet to 1,100 feet upstream of South Estes Street, while the erea
covered by the Standard Project flood verles from 100 feet wide to 2,100 feet
wide In the seme reach. TheStendllrd Project flood reaches the fringe of
e large N'lsldentlel linea on the left bank downstream from South Estes
Street. from South Wedsworth Boulevard to South Lowell Boulevard large
resldentlel arees on the left bank are subject to flOOding. from South
Lowell 80ulevllrd to ,the mouth seVilral large mobile home perks ere subject
to flooding, as well es many penmanent residences. Scattered commercial
developments In the study reech ere subject to flooding Including the
lergoBeer Velley shopplngcentor at South Sheridan Boulevard'.
The Denver offloe, National Oceanic end Atmospheric AdmInistratIon
(NOAA) Netlonel Weather Service Is responsible for providing flash flood
warnings for streams In the Oenver erea. The Weether Service redar facll-
Ity et Llman. Colorado Is capable 01 Immediate detection and evaluation
of rainfall Intensity and IOCIITlon and movement of storms end ereas of
heavyr..lnfell. Rlvers1'ageforecestsforBeerCreekaremlldebythe
River forecest Center at Kenses City through the River District Office
et Denver, and are besed on rader coverage, reports 1rom one river
STllTlon, and reports from about:; ralnhll reporting steTlons In or near
the basin. Weather Service Info~tlon Is rele~sed TO the news madre
~nd to local officials In the area of potenTial flooding. The lead tIme
between forecest end 1100d crest Is normally ebout 6 hours.
Large1100dslnotheroonselypopulaTedereessuchasGreatfalls.
Montana In 1964 and In Rapid City, South Dakota In 1972 have demonstreted
thl'lt some people Ignore flood "~r~lngs or evacuation ",ppeels until the
danger Is c1os9 lit hand. Fest peeking tllOO during II 11lr9fl flood on
B

Bear Creek calls for IlTm'Idlate emergency action to reduce property d amage
and save lives. Those Who linger or do not respecT the hazard of floods
endanger not only themselves bUT those who might leter be required to
r!Skthelr Ilvas In rescuoattempts.
Water velociTies would be a hazerd during lerge floods In the study
reach. Water velocities over The Bear Creek flood plel~ cen reech 1 feet
per second. Velocities greater Then 3 feeT per second combined with flood
depth of 2 feet or more are generally considered hazerdous. This would
occur at many locations along Beer Creek during a lerge flood. Travel
through any floodel;l area should be avoided 9XCept forernergency actio ns.
Duration of flooding Is IIlsoo 1100dhazard fedor. A large flood
may perslst for up to 12 hours. Steady rains combined with snowroolt run-
off can result In high flows for 30 days or more, eauslng severe erosion
damege.

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