My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
WSP08403
CWCB
>
Water Supply Protection
>
Backfile
>
8001-9000
>
WSP08403
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 2:48:02 PM
Creation date
10/12/2006 2:58:08 AM
Metadata
Fields
Template:
Water Supply Protection
File Number
8220.101.17
Description
Glen Canyon Dam/Lake Powell
State
AZ
Basin
Colorado Mainstem
Date
1/1/1999
Author
BOR
Title
GCD Modifications to Control Downstream Temperatures: Plan and Draft Environmental Assessment
Water Supply Pro - Doc Type
EIS
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 />Executive Summary <br /> <br />However, this does not necessarily mean that humpback chub will be unable to <br />fmd opportunities once the cold-water restraints are eliminated. For example, it is <br />a well know fact that the humpback chub thrive in the wann water of the Little <br />Colorado River and that they compete very successfully against carp, catfish, and <br />other competitors in that wannwater system. Clear. summer-long, wanned <br />releases (about 13.50C) from Flaming Gorge Dam have also improved conditions <br />for native fish populations even though non-native fish are present in great <br />numbers. <br /> <br />. Predator Controls - Modeling studies underway by the Grand Canyon <br />Monitoring and Research Center suggest that carp and channel catfish populations <br />may need to be controlled by methods beyond the timing and duration of <br />temperature controls. Physical controls (harvesting) may be needed to reduce <br />predation on native fish in specific areas. Careful monitoring of these competitors <br />would be an important part of the proposed alternative. If physical controls are <br />needed, the Adaptive Management Work Group may reco=end to the Secretary <br />of the Interior actions that would be appropriate given the details of the <br />monitoring results and the problems that are identified. <br /> <br />. Rainbow Trout - Numerous experiences at other dams strongly suggest that the <br />proposed wannwater release of up to 150C would benefit the rainbow trout <br />fishery below Glen Canyon Dam by removing temperature stresses. The current <br />SOC (460F) releases are well below the 150C (590F) optimum for rainbow trout. <br />Reservoir modeling studies also suggest that nutrient and detritus releases from <br />the darn would increase, potentially improving the food base for trout in the Lees <br />Ferry reach of the river. <br /> <br />Adaptive Management - Adaptive management is an essential component of the <br />proposed alternative. Because of the complexity of the ecological interactions in the <br />Grand Canyon, no one (fixed) plan of operation could be expected to optimize the goals <br />of the proposed temperature control alternative. Modeling and predictions are of limited <br />usefulness when dealing with complex environmental systems. It is clear that <br />temperature release patterns (operations) will need to be adjusted and evolve as our <br />knowledge increases from each successive year of testing. Carefully monitored <br />experiments are necessary to assure that these adaptations help (not hann) the resources. <br />The testing and monitoring program would be developed by the Glen Canyon Technical <br />Work Group and Grand Canyon Monitoring and Research Center within the existing <br />adaptive management process. The Glen Canyon Adaptive Management Work Group <br />would then review this work and make reco=endations to the Secretary of the Interior <br />for implementation. <br /> <br />Monitoring - The temperature control alternative included in this assessment proposes <br />to avoid or mitigate the potential adverse impacts that have been identified in this <br />assessment. It also includes the Adaptive Management Program and Grand Canyon <br />Monitoring and Research Center to monitor and evaluate management options to avoid <br />unforseen impacts that may occur in the future. And finally, if monitoring shows that <br />wannwater releases do not to benefit endangered species, cold-water releases would be <br /> <br />IV <br />
The URL can be used to link to this page
Your browser does not support the video tag.