PERMFILE124206

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 04e-2 AVF Evaluation Fish Creek Mine
• Media Type: D
• Archive: No

red renectances on the color infrared photography were indications of shallow groundwater
• conditions (as opposed to reflectances indicative of vegetation type, topographic position,
relation to nearby reservoirs, etc.) In addition, alluvial water levels were evaluated for seasonal
variation during [he growing season as well as [he elevation of the capillary fringe in relation [o
tl~e terrace surfaces and expected rooting depths for agriculturally useful species of plants (i.e., to
allow subirrigation). Soil test pits had been previously described by Walslr (1980) and all
pertinent data concerning observations of moisture, soil mottling, rooting depth, and soil textures
was reviewed. These data are provided in Appendix Il. All of these data were compared
upstream and downstream to determine if patterns were apparent regarding potentially
subirrigated areas that would later guide more detailed field studies.
based on [he conclusions arrived at from review and evaluation of the previously collected
information, test pits were installed on the valley Floor to further verify the presence of
srbirrigation of agriculturally useful species (see Map 4).
During the test pi[ investigations, records were kept of the presence of vegetative species which
are representative of the terrace surface being evaluated. In addition, data were collected with
respect [o subsurface observations of soil moisture (including subsequent laboratory analyses),
soil mottling, rooting depth of agriculturally useful species, and field soil textures (Appendix I).
Whenever possible the test pit elevations were also related to nearby alluvial water table
elevations. 1~he following narrative presents the detailed analyses of subirrigation conducted in
the drainages of Fish Creek.
risk Creek
• Tlie limit of the subirrigation investigation in the Fish Creek valley was based on the extent of
valley bottom deposits along Fish Creek meeting the geomorphic criteria for an AVF (as
described in Section II and delineated on Map 2). With respect to these areas, all available data
were reviewed and additional field investigations were undertaken (where needed) in order to
delineate areas where subirrigations agricultural activities are occurring. subirrigation
investigations were limited to include only the lower Ti, T2, and T} terrace deposits along Fislr
Creek (Map I).
Evaluation of Infrared Photoeraahy
Tlie Fish Creek drainage was initially checked to see where enhanced moisture conditions were
suggested for agriculturally useful species on the color infrared photography. The initial review
of the photography revealed several areas with red reflectance, with several shades of red. In the
field, several areas were verified as having enhanced moisture conditions associated with various
types of vegetation. •For example on upper Fish Creek in Section 16, TSN, R86W the moderate
red shades along the Fish Creek Ti terrace are primarily associated with the concentrations of
shrubs such as shrubby cinquefoil, silver sage, rubber rabbit brush, and willow (see vegetation
description for TI terrace, Appendix i, AVF Test Pit Fish-}). In the same vicinity a light red
blush was observed on the T2 terrace which includes smooth brome hayfield, while T} terrace
landfornis, also in smooth brome, had little if any red tinge on the photos.
Downstream, areas of native vegetation indicate varying reflectances based on fence lines,
indicating agricultural utilization differences. ignoring the changes in hue caused by the
variability in utilization, native vegetation is obviously supplied with additional moisture on the
• alluvial fill below three reservoirs in Section 15, TSN, R86W. Moderate shades of red are also
noted in an area of native vegetation on the valley bottom below a spring (SEI/4, NEI/4, Section
I:environ\tncy\documendExhibTA G 01/16/98
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