WSP02772

• File Number: 8240.300.31.B
• Description: San Juan River - FWS Flow Recommendations
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 9/16/1998
• Author: Biology Committee
• Title: Flow Recommendations for the San Juan River - Draft Report
• Water Supply Pro - Doc Type: Report/Study

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CHAPTER 8: FLOW RECOMMENDATIONS FOR THE RECOVERY
OF ENDANGERED FISH. , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . 8 - 1
RECOMMENDED HYDROGRAPH CONDITIONS ............................ 8 - 2
RESERVOIR OPERATING RULES... . . ... . . . . . . . . . . .. . . . . . . . . . . . . , . . . . . ., 8-7
MODEL RESULTS...........,....................................... 8 -10
Hydrologic Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 10
Backwater Habitat Results. . . . . . . . . . . . , . ' . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 12
Fish Recovery, Water Development and Flow Recommendations. . . . . . . . . . 8 - 18

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REFERENCES . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . , . . R - 1

GLOSSARY .........................,......................,............. G - 1

LIST OF TABLES

Table S,1.

Table 2.1.

Table 2.2.

Table 2.3.

Table 2.4.

Table 2.5.

Table 2.6.

Table 2.7.

Table 2.8.

Flow requirements needed to produce important biological responses
and habitats in the San Juan River. .....,............................ S - 4

The major habitat types mapped in the San Juan River from color plates
taken from airborne videography. ......,..................,'........ 2 - 7

Reach definitions, variables considered, and their mean values
within each reach used in defining geomorphically different reaches. ,......' 2 - 8

Comparison of storm magnitude and frequency for the Colorado River
at Cisco gage, Green River at Green River gage, and San Juan River

near Bluff gage. . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 14

Comparison of hydrograph statistics for pre-dam (1929 to 1961),
post-dam (1962 to 1991), and study periOdS (1992 to 1997)
for the San Juan River near Bluff, Utah. . . . . . . . . . . . . . . . . . . . . . . . . ' , , . . . 2 - 16

Eight general categories of habitat types on the San Juan River. '......... 2 - 22

A comparison of habitat quality features in runs and riffles
by geomorphic reach for 1995, 1996, and 1997 combined
in the San Juan River. ...........................,............... 2 - 27

A riverwide comparison of habitat quality features for five sample periods
in the San Juan River. ,.......................................... 2 - 27

Habitat types as a percent of total wetted area (TW A)
for the 15-mile reach of the Colorado River at three flow levels. ........... 2 - 29

T - 3

Table of Contents
Draft Flow Report

SJRIP Biology Committee
16 September 1998