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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Figure 4.12. The response of invertebrates biomass estimates
during two separate time periods corresponding to a stable period
(above) and an unstable period (below) in backwaters
of the San Juan River. ........................................... 4 - 38

Figure 4.13. The response of periphyton biomass estimates
during two separate time periods corresponding to a stable period
(above) and an unstable period (below) in backwaters
of the San Juan River. ........................................... 4 - 39

Figure 4.14. Locations of wild Colorado squawfish collections in the San Juan River
from 1987 to 1996. . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 43

Figure 4.15. Simple verses complex habitat areas mapped
from River Mile (RM) 106.9 and 129.9 of the San Juan River. ............ , 4 - 45

Figure 4.16. Flows during August UDWR YOY sampling trips on the San Juan River. .... 4 - 56

Figure 4.17. Length-frequency histogram for flannelmouth sucker
collected during October USFWS electrofishing surveys
on the San Juan River (RM 52 to 158), Age-2 fish in 1995 (1993 cohort)
are in the 176 to 250 mm size range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. 58

Figure 4.18. Average catch rates for juvenile and adult flannel mouth
and bluehead sucker collected curing October (1991-97) USFWS
electrofishing surveys in the San Juan River between RM 2 and 158. . . . . . . . 4 - 58

Figure 4.19. Flows during spring and fall USFWS electrofishing trips
on the San Juan River. .....................,.... " . . . . . . . . . . . . . . 4 - 59

Figure 4.20. Regression line fitted to plot of average catch rates of flannelmouth sucker
collected during October (1991 to 1997) USFWS San Juan River
electrofishing surveys versus sampling trip discharge (as measured
at USGS gage 09371010, Four Corners, New Mexico), . . . . . . . . .. . . . . . . . . 4 - 59

Figure 4.21. San Juan River discharge (as measured at USGS gage 09371010,
Four Corners, New Mexico) versus average juvenile flannel mouth sucker
condition. Condition factor was determined using data collected
by USFWS electrofishing surveys (RM 52 to 158)
within designated reaches, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 61

Figure 4.22. San Juan River discharge (as measured at USGS gage 09371010,
Four Corners, New Mexico) versus average adult f1annelmouth sucker
condition. Condition factor was determined using data collected
by USFWS electrofishing surveys (RM 52 to 158)
within designated reaches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 61

SJRIP Biology Committee
16 September 1998

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Table of Contents
Draft Flow Report