My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD01902
CWCB
>
Floodplain Documents
>
Backfile
>
1001-2000
>
FLOOD01902
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
11/23/2009 1:09:07 PM
Creation date
10/4/2006 10:26:53 PM
Metadata
Fields
Template:
Floodplain Documents
County
Pitkin
Community
Aspen
Title
Drainage Facility Capacity Analysis of City of Aspen
Date
9/1/1998
Prepared For
Aspen
Prepared By
WRC Engineering, Inc.
Floodplain - Doc Type
Project
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
67
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 />in May was assumed to increase by about IS inches. <br /> <br />d. Methodology <br /> <br />The runoff from snowmelt in two basins were estimated - S par Gulch and Vallejo Gulch. <br />Spar Gulch consists of Sub-basins 14,22,23, and 24 as defined in the CUHP/SWMM <br />analysis, and Vallejo Gulch is Sub-basin 16, In the CUHP/SWMM analysis the runoff <br />from the Sub-basins was routed down to Original Street. To simplify the analysis, the <br />HEC-I model combines the four basins comprising Spar Gulch into one basin and there <br />is no routing analysis. The outflow from Vallejo Gulch is calculated at Durant Street. <br /> <br />HEC-I also can model the infiltration of water into the ground by several different <br /> <br /> <br />methods. This study used a uniform infiltration rate to estimate the amount of in filtration <br /> <br /> <br />from snowmelt. It was assumed that snowmelt would have been occurring previously and <br /> <br /> <br />the ground would already be saturated, Infiltration would then occur at a constant rate, <br /> <br /> <br />and there would also be no initial loss due to depression storage, etc, The model also <br /> <br /> <br />ignored the possible effect of base flow due to previous ground water infiltration <br /> <br /> <br />reentering the runoff further down-gradient <br /> <br />e. Results <br /> <br />Tables 12 and 13 provide the results of snowmelt analysis for Spar Gulch .and Vallejo <br />Gulch, respectively. The peak flow expected from snowmelt for these size watersheds <br />should vary little from year to year and from day to day. The magnitude of the peak <br />snowmeltrunoffis also very small in comparison to rainfall runoff, although it will occur <br />over a much.longer period of time <br /> <br />0, SNOW11EL T ANALYSIS - NATURAL AND MANMADE <br /> <br />1. Introduction <br /> <br />The effect that manrnade snow would have on the peak runoff from the watershed was also <br />estimated. It was assume that an additional IS inches ofmanrnade snow would be applied on the <br />Spar Guich basin and the Vallejo Gulch basin between an elevation ofS,OOO feet and 9,000 feet. <br />All other factors and were identical to those previously discussed for natural snow runoff, <br /> <br />20 <br /> <br />, <br />:'1 <br />
The URL can be used to link to this page
Your browser does not support the video tag.