9601

• UCREFRP Catalog Number: 9601
• Author: Montgomery Watson.
• Title: Yampa River Basin - Small Reservoir Study Phase 2 Report.
• USFW Year: 2000.
• USFW - Doc Type: Steamboat Springs, CO.
• Copyright Material: NO

August 2000 CRWCD * Y Riser Basin Small Resem= Study - Phase 2 Report * Page • 28
to high shrink-swell potential. The typical profile for these soils grades from a loam at the surface
into clays of low to high plasticity at a depth of 20 to 30 inches.
' Geotechnical considerations at this site include:
• Over steepened slope along the night abutment
• Depth of the landslide deposits for the left dam abutment are unknown
• Potential to remobilize landslide
Ecological Evaluation
Riparian habitats and wetland along Little Bear Creek at the Little Bear 2 reservoir site are similar to
Little Bear 1, but the extent of narrow-leaf cottonwoods in the riparian corridor is much more
' extensive than at Little Bear 1. Relatively dense stands of narrow-leaf cottonwood grow along Little
Bear Creek and also along tributary side drainages in vicinity of the Little Bear Creek bottom. The
narrow-leaf cottonwood community also becomes more expansive near the upper portion of the
proposed reservoir basin. Other habitats present within the proposed reservoir basin area include big
sagebrush / grass and mixed shrub communities. These habitats are similar to those described for
Little Bear 1. Photo LBear#2-3 (refer to Appendix B) shows a representative view of vegetation
' communities supported within the reservoir basin area.
The creek channel along most of the reservoir basin area was less incised and more sinuous than at
the Little Bear 1 site. As a consequence, wetland development was more extensive than that observed
' at Little Bear 1. Willow / alder and rush / sedge / grass wetlands often extended outside of the
immediate vicinity of the flowing creek channel especially where incised channel embankments were
not present.
t Aquatic habitat within the creek channel consists primarily of riffles and runs, but boulders and large
woody debris piles have created a number of pools and drop structures along the creek bottom.
' Average stream width is 10 to 15 feet. Bottom substrate was composed primarily of sand, gravel, and
small to large cobbles. The stream at this site was judged to provide potentially suitable habitat for
brook trout and possibly other trout species.
' Evidence of beaver tree cutting was noted in areas supporting narrow-leaf cottonwoods, but no
beaver dams or beaver ponds were observed in the stream channel. One raptor nest was observed in
the upper branches of a narrow-leaf cottonwood in the drainage bottom. The size and configuration
of the nest as well as the nearby presence of an adult great horned owl indicated possible use of the
' nest by that species. The Little Bear 2 reservoir site is near the lower elevation limit for boreal toad,
but few areas of suitable shallow, still water breeding habitat were observed at this site. The Little
' Bear 1 reservoir site is above the upper elevation distribution limit for the Ute ladies'-tresses orchid.
4.1.3.3 South Fork 1 Reservoir Site (Site 35)
' General
The South Fork 1 reservoir site is located north of Craig in the Fortification Creek drainage basin, as
' indicated in Figure 6, Field Re<armaiss Sites in the Louer Y Riwr Study Area. It is accessed via
Colorado Highway 13 and County Road 40. The site is located along County Road 40, approximately
3 miles southeast of the Highway 13/County Road 40 intersection. The dam would be located at an
' elevation of approximately 7,200 feet, as shown in Figure 12, South Fork I Reserwir Site.
The property is privately owned with land use being primarily agricultural/ranching in nature. A
' reservoir at this site could potentially serve several downstream agricultural users on South Fork
MonWmy Watson •P.O Box 774018 * Steam& & Spri Colorado 80477 * [phone]
' W/WP10551M-2Rip-
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