My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
WSP03614
CWCB
>
Water Supply Protection
>
Backfile
>
3001-4000
>
WSP03614
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 12:51:16 PM
Creation date
10/11/2006 11:52:28 PM
Metadata
Fields
Template:
Water Supply Protection
File Number
8270.100
Description
Colorado River Basin Water Quality/Salinity -- Misc Water Quality
Basin
Colorado Mainstem
Water Division
5
Date
1/1/1981
Author
USDOI
Title
Quality of Water - Colorado River Basin - Progress Report No. 10 - January 1981 -- Part 1 of 2 -- Title Page through Part IX - page 98
Water Supply Pro - Doc Type
Report/Study
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
108
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 />SUMMARY (continued) <br /> <br />Projections made using <br />three significant ways: <br /> <br />CRSS will differ from those previously made In <br /> <br />~.. <br />o <br />Co\,) <br />00 <br /> <br />1. The model dynamically routes water and salt through the system <br />using a monthly time step, more accurately reflecting tlle time lags, <br />changes in reservoir storage, ano related buffering of sali~ity as <br />it travels through the system. Previous techniques applied projected <br />annual changes in depletion and salt loading to a water and salt <br />load accounting which assumed that the system was at a steady state <br />of average conditions for that point in time. <br /> <br />2. The data hase used in eRSS utilizes the period beginning in <br />1906, while previous analyses of future salinity have been based upon <br />the period beginning in 1941. This change places the analyses of <br />salinity in the same context 85 water supply an~lyge~ conducted by tile <br />Department of the Interior. <br /> <br />., <br /> <br />Traditionally, there has been some disa~reement regarding the use <br />of water supply records from the first quarter of tllis century to <br />determine firm water supply. During hearings on the Colorado River <br />Basin Project Act (Public Law 90-537) in the middle 1960's, experts <br />testified that, although the river has exhibitecl a long-term Rnnllal <br />flow of 15 million acre-feet, the safe usable volume np.eds to be hasecl <br />upon a lesser runoff to reflect the impact of drought periods. <br />Therefore, the water supply studies prepared by the Department of the <br />lnterior; <br /> <br />a. utilize a combination of stream flow and reservoir storage <br />releases which reflect the most adverse period of record which <br />occurred in the 192R to 1964 time frame to determine firm water <br />supply for consumptive use purposes and <br /> <br />b. utilize the long-term hydrologic record beginning in 1906 <br />to determine power production and in the future to analyze <br />salinity impacts. <br /> <br />3. Rather than a ~ingle projection of mean salinity at future points <br />1n time, the results of a set of historical hydrologic events provide <br />an idea of the range of salinity that can be expected if the p.xtreme~ <br />of history are reflected in the future. The result ing probabi 1 ity <br />projections of expected salinity levels identify the most probable <br />future salinity levels anrl provide a view of the impacts of rlrought <br />and flood events on the salinity of the Colorado River. <br /> <br />. <br /> <br />Of the three analytic differences described above, the change 1n the <br />assumptions regarding the period of record used for analyses has the most <br />significant impact because of the larger average virgin flow that results. <br />The average Lee Ferry virMin flows during the 1941-1978 and 1906-74 period <br />are about 14 and 15 million acre-feet, respectively. Although the salt <br />loading also increases marginally, the resulting additional diluting water <br />results in siAnificantly lower future salinity projections when the longer <br />term nydrology is ugen. However, by using the longer period of record, <br /> <br />2 <br />
The URL can be used to link to this page
Your browser does not support the video tag.