My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD09620
CWCB
>
Floodplain Documents
>
Backfile
>
9001-10000
>
FLOOD09620
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 10:09:54 AM
Creation date
10/5/2006 4:29:44 AM
Metadata
Fields
Template:
Floodplain Documents
County
Moffat
Basin
Yampa/White
Title
Regional Interdisciplinary Paleoflood Approach to Assess Extreme Flood Potential
Date
10/1/2000
Prepared For
Moffat County
Prepared By
USGS
Floodplain - Doc Type
Educational/Technical/Reference Information
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
27
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />2980 <br /> <br />JARRE1T AND TOMLlNSO~: REGIONAL INTERDISCIPLINARY PALEOFLOOD METHOD <br /> <br />1000 <br /> <br />"""'~""""""" <br />PMF, Stagecoach Reservoir <br /> <br />Max Paleoflood <br /> <br />Envelope curve lor <br />Yampa RIver (fig. 9) <br /> <br />FEMA <br /> <br /> <br />._..._..._...._.........__h......h_....__..__.... <br /> <br />.!! <br />~ <br />E <br />" <br />i:' <br />. <br />" <br />u <br />. <br />is <br />'" <br />. <br />. <br />.. <br /> <br /> <br /><-..---.: t.. <br />:II ._......... <br />....At.-~_......... <br />EMA (P=9,OOO yrs; <br />station skew) <br /> <br />EMA (P=9,OOO yrs; <br />ave. skew=-O.03) <br /> <br />Peak Discharge <br />95% confidence limits <br /> <br />10 <br />1 <br /> <br />10 <br /> <br />100 <br /> <br />1000 <br /> <br />10000 <br /> <br />Recurence Int~rval, years <br /> <br />Figure 12. Flood-frequency relations for the Yampa River at Steamboat Springs gage (09239500) and <br />paleoflood data (shown as rectangle) using at.site and average skew with 95% confidence limits. P denotes the <br />paleoflood length of record. The envelope curve value (Figure 9) for maximum flooding in the Holocene is <br />also shown. The flood-frequency relation for the Yarnpa River at Steamboat Springs derived from rainfall- <br />runoff modeling [Federal Emergency Management Agency, 1976J and the probable maximum flood for Stage- <br />coach Reservoir on the Yampa River upstream from Steamboat Springs are shown for comparison. <br /> <br />modeling which routed the excess rainfall and snowmelt <br />through Elkhead Reservoir and paleoflood study results <br />showed that the Elkhead Dam would not be overtopped from <br />the site-specific PMP. These results were accepted by the Col- <br />orado State Engineer for dam safety certification with no mod- <br />ifications to the existing structure. <br /> <br />7, Conclusions <br /> <br />A regional, interdisciplinary paleoflood approach provides a <br />more thorough assessment of flooding and with site-specific <br />PMP/PMF studies provides dam safety officials with new in- <br />formation to assess extreme flood potential. Interdisciplinary <br /> <br /> 1000 <br /> . gage <br /> ungagedslte <br /> paleoflood <5000 yrs <br /> .& paleoflood >5000 Yo's <br /> _.~ 10-yr <br /> n-100_yr <br />.!! .oo SOO-yr <br />~ '--1,OOO-yr <br />E --10,Ooo-yr <br />" <br />~ <br />. <br />" <br />u <br />. 100 <br />is <br />'" <br />. <br />. <br />.. <br /> .(' <br /> . <br /> .' . <br /> . . <br /> 10 <br /> 1 10 <br /> <br />Envelope curve for <br />NW COlorado <br /> <br />, <br />, <br />,-xli::},: <br />. i.:;"/ ~....- <br />..'.'/ ./ II <br />, ..... . <br /> <br />/.;~F:~~~'::;:~:!(' . . <br />~ .......~ )I......../f( <br />, .~.',o. II~.'S."" II <br />, ,4"'" / )( <br />Ir-J....~.;..~)( If )( )( <br />,._.__...:.... .4: . <br />ll"'j(.lt'M'- . <br />......_~ ..... ,;;" X X X <br />..... ..' ]1(' <br />. ,. <br />x ..... ....~1Il <br />...... II'" lCx <br />.. X . x <br />i. . "l' <br />i. . x <br />x . I(~. x x "'lot <br />. <br /> <br />. <br /> <br /> <br />. <br />.. <br /> <br />. <br /> <br />.~ <br />. <br /> <br />. <br /> <br />. <br />'" <br />. . <br />o <br /> <br />. <br />. <br /> <br />.. ...... ~ . <br /> <br />I( x'S.:: I( I( lC <br />..lCX lClC <br />o <br /> <br />o <br /> <br />o <br /> <br />o . <br /> <br />o <br /> <br />100 <br />DraInage area, km2 <br /> <br />1000 <br /> <br />10000 <br /> <br />Figure 13. Relation between contemporary and paleoflood peak discharge and drainage area with flood- <br />frequency curves for eight stations (Table 3) superimposed for northwestern Colorado. <br />
The URL can be used to link to this page
Your browser does not support the video tag.