PERMFILE70173

• Permit No: C1981039
• IBM Index Class Name: Permit File
• Doc Name: Slide Plan 10/4/90
• Section_Exhibit Name: Reclamation Project Binder
• Media Type: D
• Archive: No

~CZ
•
Mr. Brent Anderson
Page Four
October 1, 1990
• The length of the diversion ditch adjacent to and upgradient from
Pit 6
• The basin area and toe of adjacent backfilled and graded slopes
• The Pit 6 access road Swale and adjacent toe and sideslopes
• The crest and toe of the hillslope paralleling the Pit 5 access
road
In the areas inspected, there-was .no _.evidence _of._major._.surficial_ or_mass
instability. However, some localized surficial erosion was evident. on both _.
the abandoned roadway which runs to the southwest from the basin area, and
adjacent to the Pit 6 access road. Vegetative cover appeared to be well
established and vigorous and, given the steepness of the regraded slopes,
appeared to be effective in stabilizing the hillslopes. Organic cover is
beginning to establish at the ground surface, although development is not as
pronounced as in the Pit 5 area, possibly reflecting the year lag in
• reclamation of Pit 6.
Inspection of the undisturbed runoff diversion indicated no significant
recent geomorphic changes. It was also noted that a minor Swale near the
former highwall crest would serve as a secondary barrier to overland flow.
In view of it's geomorphic stability and value in controlling long term
erosion, it is recommended that this diversion be retained.
The only portion of Pit 6 where existing or significant potentiai.,for future ~' /
erosion was identified was along the abandoned road running southwest from
the basin area up to the reclaimed slope. On the south side of the abandoned
and reclaimed roadway a small Swale and adjacent berm limit.downslope flow ~,
resulting in movement of runoff parallel to the road. Over time, this
artificial channelization of flow has resulted in localized surficial erosion
of the Swale. However, given the limited width of the effected area and
existing vegetative cover, stabilization with straw bales placed and staked ._
down every 50 - 70 feet should be effective. ,
The bottom of the small basin at the northern end of the Pit 6 area was
moist, although there was no standing water. There was also no evidence of
significant drainage from the basin, so it must be assumed that most of the
water which collects in this area is lost through evaporation or seepage.
The basin is far enough from adjacent toe slopes that saturation is not a
problem. There was also no evidence of toe movement or instability in the
area surrounding the basin.
• Minor erosion was noted in the ditches paralleling the Pit 6 access road. .. ..~.
The effected areas are relatively small and the problem could be easily.. ;'
remedied through placement of rock check dams, riprap, or revegetation of the i
ditches and temporary stabilization with straw bales.