_GENERAL DOCUMENTS - C1981017 ‎(247)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎ 1996 Correspondence
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

Coal Basin Tract
August 18, 1996
Huntsman Ridge exceed 11,000 feet.
There are deposits of alluvium and colluvium in the Dutch Creek
drainage. On the north side of Dutch Creek is a floodplain and
first terrace level composed of clay-sized fractions through boul-
ders. The south side is a steep-faced scarp about 76 feet high, a
measurement obtained by GPS analysis. The top twenty feet which
overhangs the creek is-covered by trees and other vegetation. This
scarp is composed mainly of clay through sand-sized particles with
subrounded rock up to 8 inches in diameter. The top half of the
scarp contains lenticular, thin dark-grey clay seams. The majority
of the scarp face below the vertical aspect is rilled creating
small fans that terminate at the debris flows in the creek. Costa
and Jarrett (1981) note that only moderate rainfall intensity is
needed to produce rills on exposed surfaces.
To the west upstream in Dutch Creek, the south bank is well covered
with firs, small bushes, and assorted grasses. This vegetation
holds in place materials that range from clay-size fractions to
subrounded rock up to 8 inches in diameter. Evidence of debris
flows can be seen in this area of the creek bed.
Above Dutch Creek on the south side is a gently sloping, grass
covered spoils pile of coal fines from past processing activities
at Coal Basin. Overall, the pile is well-vegetated, stable, and
drained by a ditch around the upper side. The volume of water in
the ditch is limited because the pile is near the top of the ridge-
line, but some erosion has taken place along the western edge of
the pile. Several small slides, or springs were noticed on the
northeast corner of the spoils pile.
Coal Basin is drained by two principle creeks, Dutch and Coal,
which flow to the east into the Crystal River. Aerial photography
shows that these creeks have not moved considerably since 1952 .
Dutch Creek is well-defined and in a relatively narrow channel to
the west of the spoils pile. Near the confluence with Coal Creek,
there is a floodplain and first level terrace to the north of the
current creek location.
CONCERNS:
1) - Dutch Creek and the revegetated coal spoils pile are located
in Sections 11 and 14, T. 10S. , R.89W. , 6th PM (Figure 1) . The
concern is the erosion of the scarp face and the coal spoils pile.
The steepness of the scarp face can be seen in Figure 2 .
The creek flows east-northeast (078° ) to the scarp face and then
takes a turn to the north-northeast (0280 ) to the flume area. The
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