My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD06561
CWCB
>
Floodplain Documents
>
Backfile
>
6001-7000
>
FLOOD06561
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/25/2010 7:09:20 PM
Creation date
10/5/2006 2:23:00 AM
Metadata
Fields
Template:
Floodplain Documents
County
Montrose
Basin
San Juan/Dolores
Title
Hydrology Addendum Montrose County
Date
11/1/2000
Prepared For
Montrose County
Prepared By
CWCB
Floodplain - Doc Type
Floodplain Report/Masterplan
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
53
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 />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />i. <br />. <br />. <br />. <br />'. <br />. <br />. <br />. <br />, <br />. <br />. <br />I. <br />. <br />. <br />. <br />,. <br />. <br /> <br />reservoir. Although the United States Bureau of Reclamation (USBR) constructed the reservoir, <br />the United States Army Corps of Engineers (USACE) is responsible for the flood control <br />operations. A formal flood control operations manual could not be obtained from the US ACE at <br />the time of this report. Therefore, this analysis has neglected any flood control effects from the <br />reservoir on flows in the Uncompahgre River. <br /> <br />The Colorado River Storage Project consists of the three reservoirs on the Gunnison River: Blue <br />Mesa Reservoir, Morrow Point Reservoir and Crystal Reservoir, Project data sheets do not show <br />significant flood storage in any of the reservoirs, Therefore, effectiveness of reservoir storage in <br />flood flow attenuation depends on reservoir levels at the time of the flood. Low reservoir levels <br />would allow peak discharges to be more effectively reduced, while high reservoir levels may <br />have little effect on peak discharges. However, even at high reservoir levels, flow through the <br />reservoir will be attenuated due to surcharge storage and travel times from the reservoir inflow <br />points to the spillway, <br /> <br />Montrose County should regulate the approximate floodplains on a case-by-case basis. FEMA <br />requires that a detailed floodplain analysis must be performed by a professional engineer and <br />submitted by the developer or development proponent for development projects involving more 5 <br />acres or more than 50 units (whichever is more restrictive). <br /> <br />Hvdraulic Analvsis <br />Hydraulic methods used for the approximate floodplain delineations shown on the Montrose <br />County FIRM panels are not available or have not been documented by FEMA, For future <br />studies, an approximate loo-year flood elevation at a particular location on the river may be <br />obtained by using the loo-year peak flow value (as provided in this report) in conjunction with <br />an acceptable hydraulic analysis. Hydraulic analyses for determining lOO-year water surface <br />elevations for approximate floodplains may be performed using FEMA's Quick-2 computer <br />program, the Corps of Engineers' HEC-2 computer program, F1owmaster, or other acceptable <br />hydraulic methods. Channel and floodplain cross-sections may be obtained from detailed <br />topographic mapping or from field surveys. Cross-sections obtained from USGS quadrangle <br />maps are not advised. <br /> <br />Floodplain Mappine <br />The existing FIRM for Montrose County depicts areas subject to lOO-year flooding based on <br />approximate technical methods. The map does not show flood profiles, base flood elevations, or <br />sufficient detail in order for County officials, engineers, developers, and land owners to make <br />floodplain determinations with any certainty. The Colorado Water Conservation Board can be <br />contacted to request technical assistance for approximate floodplain analyses as needed. <br /> <br />8 <br /> <br />- <br />
The URL can be used to link to this page
Your browser does not support the video tag.