WSP07697

• File Number: 8240.200.10.B
• Description: UCRBRIP - Riverine Fish Flow Investigations
• Basin: Colorado Mainstem
• Date: 7/1/2001
• Author: CDOW
• Title: Riverine Fish Flow Investigations 2001
• Water Supply Pro - Doc Type: Publication

Wetted stream width was found to be higher on the Yampa River for most flows of

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width is determined using channel surveys. But even with the 18 m width the Dolores had the

lowest density estimate for bluehead of all sites. Density of roundtail chub and catfish were

only somewhat less than the Colorado stations and higher that the Yampa River at Duffy and

Sevens.

Table 9. Dolores River population estimates with 95% C.I. and (recaptures), and density
estimates (No./IOOOm') for the Big Gypsum station, 2000.

Bia GVD, 2000 BiO Gyp, 200
NO./km ",C.I. No./IOOOm
( recaos
Total fish 197:1:15% (102) 10.9
Bluehead Sucker 3f67% (3) 0.17
Flannelmouth S 36:1:39% (15) 2.0
Roundtail Chub 81:1:16% (67 4.5
Green Sunfish 5:1:58% (5) 0.29
Channel Catfish 69f61 % (8) 3.8
Black Bullhead 14:1:78% (4) 0.76
CarD 24:1:181% (1) 1.35
Brown trout 1.2:1:NR (0) 0.07

Habitat Comoosition

Analysis of habitat composition has been completed for two sites, the Duffy on the

Yampa River and the Com Lake site on the Colorado River. Stewart (2000) presents the

methods and documentation for these results but this report only provides a summary of his

presentation of that data.

interest. At a flow of 600 cfs the wetted width at Duffy is 63.1 m compared to 48.6 m at Com

Lake (Colorado River). An adjustment was made for this report to present fish density

(number per surface area) based on the wetted width at a typical base flow. In prior reports

the fish density was based on the Colorado River having a wider channel (based on bankfull

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