2008-03-21_PERMIT FILE - C1980007A ‎(7)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 3/21/2008
• Section_Exhibit Name: Exhibit 55B Stream Channel Parameters & Changes Due to Mining-Induced Subsidence
• Media Type: D
• Archive: Yes

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Table 3
Pre-Mining Stream Channel Hydraulic Characteristics

Basin

Number Channel Thalweg Slope
N

Average Lower
Reach

Dominant Discharge (Q) Near Mouth
Flow
(c{s) Width (ft) Depth (ft) Velocity (ft/sec)
5 8.8% 6.7% 4.2 6 0.2 2.9
6 9.89% 6.48% 2.1 4 0.2 2.7
26 10.48% 5.57% 4.9 6 0.3 2.9
27 12.33% 9.55% 2.2 4 0.2 2.7
28 19.57% 16.34% 2.1 4 0.2 2.7
29 9.73% 4.79% 4.9 6 0.3 2.9
30 12.33% 8.99% 2.1 4 0.2 2.7
31 10.16% 19.60% 2.0 4 0.2 2.7
32 8.47% 4.02% 13.3 10 0.4 3.2
33 14.00% 20.66% 2.4 4 0.2 2.7
35 5.25% 5.61% 64.0 22 0.7 3.8
36 7.09% 5.92% 25.8 14 0.5 3.5
37 7.2% 5.4% 35.0 16 0.6 3.5
i
Table 4
Effects Of Subsidence On Stream Channels
I
Pre-Mining Slope (%) Change in Slope Post-Mining Slope
Basin
No.
Average Lower
Reach Maximum
Subsidence (ft) Maximum
Negative Maximum
Positive Minimum Maximum
5 8.80% 6.70% 7.14 -1.70% 0.87% 5.0% 7.6%
6 9.89% 6.48% 8.47 -1.00% 0.99% 5.5% 7.5%
26 10.48% 5.57% 8.63 -0.11% 0.46% 5.5% 6.0%
27 12.33% 9.55% 9.42 -2.30% 2.24% 7.2% 11.8%
28 19.57% 16.34% 9.40 -2.50% 2.54% 13.8% 18.9%
29 9.73% 4.79% 9.42 -2.50% 2.46% 2.3% 7.3%
30 12.33% 8.99% 9.42 -2.50% 1.75% 6.5% 10.7%
31 10.16% 19.60% 8.63 -1.30% 1.39% 18.3% 21.0%
32 8.47% 4.02% 9.42 -2.40% 1.71% 1.6% 5.7%
33 14.00% 20.66% 9.65 0.00% 3.95% 20.7% 24.6%
35 5.25% 5.61% 9.33 -1.50% 1.99% 4.1% 7.6%
36 7.09% 5.92% 9.00 -2.20% 1.21% 7%
3. 7.1%
37 7.2% 5.4% 7.00 -1.90%* 1.90%* ND ND
(1) Slope range given for lowest reach potentially impacted by mining.
* Estimated