WSP12639

• File Number: 8220.101.10.A
• Description: Colorado River - Water Projects - Glen Canyon Dam-Lake Powell - Glen Canyon AMWG
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 10/1/2004
• Author: Schmidt - Topping - Grams - Hazel
• Title: System-Wide Changes in the Distribution of Fine Sediment in the Colorado River Corridor Between Glen Canyon Dam and Bright Angel Creek - Arizona - Final Report - 10-01-04
• Water Supply Pro - Doc Type: Report/Study

Figure 18. Map showing Glen Canyon and locations of cross-sections that have been measured since 1956 (Grams
et aI., 2004, fig. 1). River miles locations are in miles upstream from the present Lees Ferry cableway.

Glen Canyon Dam .-.,~ \\
'y\
~ ~\
~)
//,.14

;;e:Ch ~8

,n
R'1~~>l:'.

~., ..... Honey Drao".t
Fwy S"ale 1!...j ~
'};.~~.'r....
1I"4.c;:--
fLI' Reach 2
~-:.:J! 9:M;e Dr."
(~( ~i
~ tj

Old Lower 'It~: ~ ~~ 1
Lees Ferry ,yr
cableway (
.~ Reacll 3
rl~ne o;l'pOS;:e . \.

'''-~i .''\.

<\'. ,,,.' I'-\-\'~--~e~~~~~ ~R'

~::;;: .. t. cablew.y ",<; '\!:.,eaCh 4

Lees Ferry .cabfe\'/3Y l]nd \\ Reach 5 dJJ'

USGS Gagmg St3tion ff.'-:.1 R .3 > .. ~, Water Holes C.:ffJyr)tl 0 0.5 1 2 Kilamctms

~~:, I I t I I I t l I
F"lICff:fel( .....-... .~- '.... ,---.- C.1veCan;'On

J

.

Legend

~ eddies:02
.. debris fans
- cross sections

River Mile locations

Table 5. Estimates of the average change in fine sediment thickness in Marble and upper Grand Canyons .
under various scenarios of seasonal sediment accumulation, relative proportion of accumulation stored in
eddies and the main channel, and proportion of the main channel where storage occurs. Bold numbers
indicate the most likely scenario for pre-dam seasonal storage of fine sediment.
Seasonal Equivalent Equivalent thickness, in meters, under three assumptions about the
sediment volume, in relative proportion of fine sediment stored in eddies and in the main
accumulation, in cubic channel and two assumptions about the proportion of the channel that
metric tons meters' can store fine sedimenF
eddies channel eddies channel eddies channel
proportion of the [0.9] [0.9] [0.9]
channel that can (0.3) (0.3) (0.3)
store fine
sediment
relative 0.1 0.9 0.5 0.5 0.9 0.1
proportion
stored in eddies
and the main
channel
1,000000 640,000 0.02 [0.04] 0.08 [0.02] 0.15 [0.00]
(0.13) (0.07) (0.01)
7,000,000 4,460,000 0.11 [0.30] 0.57 [0.17] 1.03 [0.03]
(0.91 ) (0.51) (0.1 0)
13,000,000 8,280,000 0.21 [0.56] 1.06 [0.31 ] 1.91 [0.06J
(1.69) (0.94) (0.19)
1 assumes bulk specific weight of fine sediment is 1570 kglm3 .
2 assumes area of eddies is 3.9 x 106 m2, and area of channel is 14.7 x 106 m2
28 System-wide Changes in the Distribution of Fine Sediment in the Colorado River Corridor...