My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
Estimating Additional Water Yield From Changes in Management of National Forests in the North Platte Basin
CWCB
>
Water Supply Protection
>
DayForward
>
5001-6000
>
Estimating Additional Water Yield From Changes in Management of National Forests in the North Platte Basin
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
3/29/2013 2:57:42 PM
Creation date
3/6/2013 10:50:04 AM
Metadata
Fields
Template:
Water Supply Protection
Description
An Independent Report Prepared for the Platte River EIS Office U.S. Department of the Interior Related to Platte River Endangered Species Partnership (aka Platte River Recovery Implementation Program or PRRIP),
State
CO
NE
WY
Basin
North Platte
Water Division
6
Date
5/12/2000
Author
Charles A. Troendle, Matcom Corporation & James M. Nankervis, Blue Mountain Consultants
Title
Estimating Additional Water Yield from Changes in Management of Ntional Forests in the North Platte Bains, Final Report
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.
/
54
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
Overall, based on the range in simulated response, water yield has decreased <br />almost 20 percent, or 3 area inches since 1860. This equates to a decrease in <br />flow of nearly 225,000 acre -feet of water from 1.3 million acres of National <br />Forest lands in the North Platte River Basin. The greatest reduction in flow <br />occurred in spruce -fir stands (3.8 inches or an 18 percent reduction) and the <br />smallest reduction occurred in limber pine. Ponderosa pine (table 7) <br />exhibited the largest initial decline (1860 to 1900) with more moderate <br />decreases since then. Given the precipitation regime estimated for each of <br />the species, the current estimates of stream flow seem reasonable for <br />lodgepole pine, spruce -fir, the forest types for which we have the most <br />stream flow data and experience. The historical change in flow, based on <br />the estimates of forest cover changes over time, also seems reasonable <br />relative to the referenced watershed experiments expressing similar changes <br />in cover density. It is difficult to say if the 20 percent change in flow, over a <br />140 -year period, would be detectable at an off -site streamgage. Perhaps it <br />would be at the forest boundary but less likely at a downstream streamgage. <br />In evaluating the historical trends in water yield, as presented in table 4, <br />several factors should be considered. There is a "lot" of fluctuation in yield <br />from 1860 — 1900 that reflects the fluctuations in stand configuration <br />mentioned earlier. Because of the fluctuations in periodic responses, one <br />should average the flow simulated for the 1860 - 1900 period at 14 or 14.1 <br />inches. At the same rime, the flow for the period from 1940 to present is <br />fairly uniform at 11.9 to 12.0 inches. Averaging flow for the 2 time periods <br />would indicate a 2.0 area inch decrease in flow occurred from 1860 to <br />present resulting in an 185,000 acre -foot decrease in water yield. The .latter <br />estimate is a more conservative but perhaps more realistic estimate of the <br />reduction in flow that might have occurred as a result of forest growth. This <br />decrease in flow is still quite large relative to total yield. Individual specie <br />responses are very consistent with how we would expect those species to <br />respond ecologically and hydrologically over time. <br />OPPORTUNITY TO INCREASE WATER YIELD FROM THE <br />NORTH PLATTE RIVER BASIN <br />Evaluation of the trends in water yield as a result of the historical changes in <br />stand structure and vegetation density was based on all NFS lands in the <br />North Platte drainage that are currently occupied by forest. Nothing was <br />assumed to have changed with respect to water, barren, grass or brush lands. <br />An evaluation of the current opportunities to increase water yield, through <br />37 <br />
The URL can be used to link to this page
Your browser does not support the video tag.