2019-06-28_REVISION - M1977004 ‎(12)‎

• Permit No: M1977004
• IBM Index Class Name: REVISION
• Doc Date: 6/28/2019
• Doc Name: Request For Amendment To Permit
• From: Homestake Mining
• To: DRMS
• Type & Sequence: AM1
• Email Name: DMC
• Email Name: THM
• Media Type: D
• Archive: No

Homestake Mining Company March 01,2019
Climate Data Project No.:0011-284
Precipitation Data for 24-Hour Storm and Reoccurrence Intervals
NOAA,2019
Pitch Project Site
Duration Average recurrence interval(years)
1 2 5 10 25 50 100 200 500 1000
5-min 0.174 0.218 0.300 0.376 0.494 0.594 0.703 0.822 0.993 1.13
10-min 0.255 0.320 0.440 0.557 0.723 0.870 1.03 1.20 1.45 1.66
15-min 0.310 0.390 0.536 0.672 0.882 1.06 1.25 1.47 1.77 2.02
30-min 0.415 0.519 0.709 0.888 1.16 1.40 1.66 1.94 2.34 2.67
60-min 0.493 0.632 0.876 1.10 1.42 1.69 1.97 2.28 2.71 3.05
2-hr 0.570 1 0.745 1 1.04 1.30 1 1.68 1.98 1 2.29 1 2.62 3.08 3.43
3-hr 0.626 0.811 1.12 1.39 1.77 2.07 2.39 2.71 3.16 3.50
6-hr 0.794 0.967 1.26 152 1.88 2.18 2.49 2.81 3.26 3.61
12-hr 1.07 1.20 1.44 1.66 2.00 2.28 2.59 2.92 3.40 3.78
24-hr 1.37 1.51 1.77 2.01 2.37 2.67 3.00 3.36 3.88 4.29
2-day 1.69 1.93 2.35 2.70 3.19 3.58 3.97 4.38 4.93 5.36
3-day 1.96 2.26 2.76 317 3.75 4.21 4.66 5.13 5.76 6.24
4-day 2.19 1 2.52 1 3.07 3.53 1 4.17 4.67 1 5.17 1 5.69 6.38 1 6.91
7-day 2.71 3.10 3.75 4.29 5.04 5.63 6.21 6.82 7.62 8.23
10-day 3.13 3.57 4.29 4.88 5.71 6.35 699 7.65 8.52 9.18
20-day 4.32 4.87 5.78 6.52 7.53 8.31 908 9.85 10.9 11.6
30-day 5.34 6.02 7.11 7.99 9.17 10.0 10.9 11.8 12.8 13.6
45-day 669 7.56 8.93 10.0 11.4 12.4 13.4 14.3 15.4 16.2
60-day 7.88 8.94 10.6 11.8 13.5 14.6 15.6 16.6 17.7 18.6
Climate Data Project Memorandum.docx BGC ENGINEERING INC.