2019-12-13_REVISION - M1980244 ‎(55)‎

• Permit No: M1980244
• IBM Index Class Name: Revision
• Doc Date: 12/13/2019
• Doc Name Note: Appendix 3
• Doc Name: Request For Amendment To Permit
• From: CC&V
• To: DRMS
• Type & Sequence: AM13
• Email Name: TC1
• Email Name: MAC
• Email Name: BFB
• Email Name: ERR
• Email Name: JPL
• Media Type: D
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NewFietds
Newmont
VLF/OSA Closure Study
Schist Island/Phase 3 Stormwater Diversion Channel
Watershed Characteristics and Lag Time Calculation
10.8(S + 1)0.7
tp 1900y0.5
tp Lag Time (hr.)
I Length to Divide (ft)
y Avg. Watershed Slope (%)
CN Composite Curve Number
S 1000/CN-10(in.)
la Initial Abstraction (0.2*S)
Input Values
Lag Time and Watershed Characteristics
Watershed Area (mi) !(ft) CN y S tp(hr) tp(min) la (in.)
Stack North 0.1140 3,897 71.00 33.9% 4.08 0.21 12.6 0.817
Stack Northwest 0.0477 2,023 71.00 1 37.4% 4.08 0.12 7.1 0.817
Schist North 0.0567 1,637 71.00 33.5% 4.08 0.11 6.3 0.817
Schist West 0.0313 1,741 71.00 26.9% 4.08 0.12 7.4 0.817
Schist South 0.0272 1,691 71.00 30.3% 4.08 0.11 6.8 0.817
SGOSA North 1 0.1346 1 1,613 71.00 38.5% 4.08 0.10 5.8 0.817
Reach Data
Reach Length Max Elev. Min. Elev Slope (ft/ft) Width Manning's
(ft) (ft) n
SGOSA142+00 TO 52+00 1,000 10,200 10,145 0.055 12 0.045
SGOSA152+00 TO 60+00 800 10,145 9,945 0.250 12 0.045