_INSPECTION - C1981019 ‎(23)‎

• Permit No: C1981019
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• Inspection Date: 10/14/2009
• Email Name: JRS
• Media Type: D
• Archive: No

Colowyo C-1981-019
14 Oct 2009
Pg 3/6
Hydrologic Balance (cont.): The Division also walked the Taylor Tributary Ditch on this
inspection. The ditch is in the northwest portion of the West Pit (in the 2009
reclamation area) and runoff from the ditch will flow into the East Taylor Pond. The
Taylor Tributary Ditch is a riprapped channel and the lower 1,450 feet has been built.
This ditch is one of two that will carry the runoff from the West Pit to the East Taylor
Pond. The Division took numerous elevation points along the Taylor Tributary Ditch
with a Trimble GeoXT. Based on the Division's field verification, it appears as though
the lower 900 feet of the Final East Pit Ditch has been built to the approved designs.
Please see the raw data and channel profile comparisons (the Division data versus
the design data) at the end of this report.
Backfilling and Grading: - Last month Colowyo completed backfilling and grading
and topsoil replacement work on approximately 35 acres in the East Pit. Since that
time Colowyo has cut contour ditches into reclamation. These contour ditches direct
the flow off of the reclaimed slopes into the permanent drainage channels that have
been constructed. The ditches appear to have a slight grade to them, which will
help ensure positive drainage. On the inspection 49 elevation points were taken to
check the post-mining topography and grades of the reclaimed slopes. All of the
points were taken with a Trimble GeoXT. The elevation measurements are all relative
elevations as they were not based on a control point. The following is a chart of the
elevation points used for determining slopes and the slopes of their respective lines.
There is also an attached map that shows the locations of the elevation points and
the slope lines and the attached raw Trimble data sheet shows the elevations as well
as the northing and easting. (Note: the point numbers listed are based on the
numbering of the Trimble unit and are based on the order in which the points were
taken.) Based on the Division's field measurements, it appears that the reclamation
work in the East Pit in 2009 was completed as required by the approved post-mining
topography map (Map 19).
GPS Pt PMT Grade Elev. PMT PMT
ID Elevation" ElevationB Line Distance Change Grade Change Grade
1 7320.3 7315.0 8-1 329.1 89.8 27.3% 60.0 18.2%
3 7318.6 7265.0 6-3 279.6 52.7 18.8% 60.0 21.5%
6 7371.3 7325.0 11-17 305.0 53.7 17.6% 65.0 21.3%
8 7410.1 7375.0 18-23 197.3 30.5 15.5% 55.0 27.9%
11 7322.2 7365.0 13-15E 150.0 70.8 47.2% 25.0 16.7%
13 7321.9 7365.0 20-22 192.2 37.9 19.7% 40.0 20.8%
15 7392.7 7340.0 32-37 246.3 73.1 29.7% 85.0 34.5%
17 7268.5 7300.0 33-34 68.0 25.3 37.2% 25.0 36.8%
18 7253.5 7280.0 49-37 613.2 88.2 14.4% 120.0 19.6%
20 7278.1 7315.0
22 7240.2 7275.0
23 7223.0 7225.0