7274

• UCREFRP Catalog Number: 7274
• Author: Pucherelli, M. J., R. C. Clark and R. D. Williams.
• Title: 1989 Upper Basin Interagency Standardized Monitoring Program - Green and Colorado Rivers Habitat Mapping Using Airborne Video.
• USFW Year: 1990.
• USFW - Doc Type: ‎(Report No. R-90-20)‎,
• Copyright Material: NO

backwaters/mile, backwater area (m2), backwater area/mile,average backwater size and standard
deviation; and number of side channels, number of side channels/mile, side channel area, side
channel area/mile, and average side channel size.

The Green River was video taped from its confluence with the Colorado to its confluence with the
Yampa, in September 1988 to acquire low-flow baseline backwater information (Pucherelli and
Clark, 1989). The lower and upper monitoring reaches were extracted from the 1988 data and
compared with the 1989 backwater data.

RESULTS

Green River

Backwater characteristics for the upper and lower monitoring reaches of the Green River are
presented in table 1. The lower reach (river-miles 0 to 120) contained 116 backwaters or
approximately 1 backwater/mile. The number of backwaters/mile was somewhat consistent ranging
from 0.8 to 1.4 within the 20-mile segments. Total backwater area was 68,457 m2 or 570 m2/mile
with an average backwater size of 590 m2. Backwater area/mile within the 20-mile segments ranged
from 285 to 864 m2/mile. Backwater number in the upper reach (river-miles 200 to 317) averaged
3.4/mile with a total area of 280,632 m2 or 2,378 m2/mile. Average backwater size was 690 m2.
Backwaters/mile within the upper reach ranged from 2.0 to 4.8, while area/mile ranged from 1,600
to 3,579 m2. Table 2 presents the side channel characteristics for the lower and upper monitoring
reaches of the Green River. The lower reach contained only 24 side channels or O.2/mile with an
area of 180,646 m2. The average side channel size was 7,527 m2. The upper reach contained 118
side channels or 1.0/mile. Total area was 992,146 m2 or 8,408 m2/mile with an average size of
8,408 m2.

Average channel width for the lower reach was 137 meters and ranged from 123 to 155 meters
among the 20-mile segments (table 3). The upper reach was considerably wider, averaging
216 meters. Average channel width for the entire Green River study area was 178 meters.

Colorado River

Backwater characteristics for the lower and upper monitoring reaches of the Colorado River are
presented in table 4. The lower reach (river-miles 0 to 110) had 170 backwaters, averaging 1.5/mile.
Backwaters/mile ranged from 1.2 to 2.2. Area/mile was 1,234 m2 with an average backwater size
of 798 m2. Area/mile ranged from as little as 307 m2 for river-miles 61 to 80, to 2,627 m2 for
river-miles 41-60. The upper monitoring reach (river-miles 140 to 170) had an average of
2.6 backwaters/mile. The area/mile was 2,137 m2, and the average backwater size was 822 m2.

Table 5 gives the side channel characteristics for the Colorado River. The lower reach averaged
0.3 side channel/mile with a total area of 264,906 m2. Side channel area/mile averaged 2,408 m2
and ranged from 444 m2 for river-miles 0 to 20 to 4,886 m2 for river-miles 81 to 100. The upper
reach averaged 0.8 side channel/mile. Area/mile was 12,337 m2 with an average size of 7,358 m2.

Average channel width for the lower reach of the Colorado River was 153 meters, ranging from
122 meters for river-miles 81 to 100 to 194 meters for river-miles 41 to 60 (table 6). The upper

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