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

0 Table 4.28.
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-.J Table 5.1.
c..:'1
Table 5.2.
Table 6.1.
Table 7.1.
Table 7.2.
Table 7.3.
Table 7.4.
Table 8.1,
Table 8.2.
Table 8.3.
Table 8.4.
Tabie 8.5.

Correlation of summer low-flow attributes with fathead minnow
autumn density in San Juan River secondary channels. .,......,........ 4 - 87

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Mean concentrations of selected trace elements under various constraints. .., 5 - 2

Acute toxicity (LCso-96 hr) concentrations for several contaminants
in the San Juan River. .............................'.............. 5 - 4

Flow requirements needed to produce important biological responses
and habitats in the San Juan River. . . . . . . . . . . . . . . . . . . . . . , . . , . . . . '. . . . . 6 - 8

Controlling habitat conditions by hydrograph season. .................... 7 - 2 '

Parameters used for comparison and optimization
in the operation modeling process. .,...............'........,...,.. 7 - 17

Summary of average annual depletions by component
for each model scenario. ......................................... 7 - 18

Range of annual depletions for each modeled scenario. ................. 7 - 20

Frequency distribution table for flow/duration recommendations. . . , . . . . . . . . . 8 - 3

Recommended daily ramp rates for 1-week, 2-week, 3-week,

and 4-week ramps. .............................................. 8 - 5

Minimum carryover storage for modeled levels of development
for use in determination of available water per figure 8.1. ................. 8 - 8

Comparison of hydrograph statistics for six levels of development
and three historical periods for the period 1929 to 1993. ................. 8 - 11

Comparison of modeled backwater area for six levels of development
and three historical periods. . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 17

LIST OF FIGURES

Figure 2.1. San Juan River Basin Recovery Implementation Program (SJRIP)
research study area. .....,..........................,............ 2 - 3

Figure 2.2. Generalized bed profiles for San Juan, Green, Yampa,
and Colorado rivers. . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 5

Figure 2.3. San Juan River near Bluff, Utah, average hydrographs for pre-dam,
post-dam, and study periods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 13

SJRIP Biology Committee
16 September 1998

T-6

Table of Contents
Draft Flow Report