My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD07468
CWCB
>
Floodplain Documents
>
Backfile
>
7001-8000
>
FLOOD07468
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/25/2010 7:11:51 PM
Creation date
10/5/2006 3:00:44 AM
Metadata
Fields
Template:
Floodplain Documents
County
Statewide
Community
State of Colorado
Stream Name
All
Basin
Statewide
Title
The Design of Encroachments on Floodplains Using Risk Analysis
Date
10/1/1980
Prepared For
USDOT
Prepared By
Federal Highway Administration
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.
/
130
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 />A fonTI similar to figure 2.2 can be used to document the assessment or <br />screening process. The form includes the three types of losses: traffic <br />related, roadway, and backwater. Under each type of loss are the factors which <br />will be used to assess that loss. For example, traffic losses are assessed <br />indirectly by detennining the number of vehicles which use the structure and <br />evaluating how frequently, if ever, they will be delayed or detoured. This is <br />done by estir,lating the overtoppi ng flood probabil ity for the alternative with <br />the smallest structure and fill. If the roadway carries a large volume of <br />traffic and will be frequently overtopped, the LTEC design process should be <br />used. Similarly, the other losses can be estimated or calculated and compared <br />to the thresholds. The thresholds must be established through the use of the <br />LTEC design process; noting the values at which a factor yields little or no <br />response. <br /> <br />If the assess~ent indicates that the LTEC process is appropriate, the encroach- <br />f"ent can be further screened by estimating the magnitudes of the various risk <br />costs and comparing these to the annual capital costs. This comparison is <br />illustrated in Table 2.1. The procedure is based on an initial trial design <br />which may be selected using traditional design concepts. The economic losses <br />(roadway, traffic related, and backwater) are determined for the one design and <br />their relative impact determined. If one or more of the economic losses are <br />relatively small compared to the other losses, they ~ay be assumed constant or <br />ignored when analyzing the other alternatives. <br /> <br />4 <br /> <br />e <br /> <br />. <br /> <br />e <br /> <br />. <br /> <br />e <br />
The URL can be used to link to this page
Your browser does not support the video tag.