TABLE 2
BASIN TIME OF CONCENTRATION CALCULATIONS
Project Number:
Subbasin ID
Subbasin
Area
(sq mile)
Composite
Curve Number
Pt S
0.0918
65
Pt E
0.0498
65
Pt NE
0.0686
65
Pt N
0.0345
65
WRF 1
0.1633
86
WRF 2
0.2246
86
WRF 3
0.3308
86
BC 1
0.4958
65
BC 2
0.2315
65
Pd N
0.2660
66
Pd S
0.1310
65
HR 1
0.1388
65
HR 2
0.0835
65
WT 1
0.1232
65
113-82323
RARE ELEMENT RESOURCES
BEAR LODGE MINE PRE-FEASIBILITY ST
Date:
2/13/14
By:
MBR
Chkd:
SR
Apprvd:
REK
Type of
Flow
Length
(ft)
Slope
(ft/ft)
Typical Hydraulic
Radius
(Channel Only)
(ft)
Travel
Time
(min)
Type of
Flow
Length
(ft)
Slope
(ft/ft)
Typical Hydraulic
Radius
(Channel Only)
(ft)
Travel
Time
(min)
Channel
2430 0.095 R Riprap
0.34
6.3
Channel
1260 0.061 Z Mtn. Stream
0.23
7.6
Channel
1610 0.062 R Riprap
0.32
5.4
Channel
1320 0.133 E Earth-lined
0.15
3.6
Shallow 190 0.279 U Unpaved
0.4 Channel
4000 0.101 R Riprap
0.96
5.1
Shallow 1300 0.277 U Unpaved
2.6 Channel
3300 0.064 R Riprap
1.30
4.3
Shallow 210 0.286 U Unpaved
0.4 Channel
7350 0.054 R Riprap
1.27
10.6
Channel
4900 0.060 Z Mtn. Stream
0.50
17.8 Channel
1810 0.010 R Riprap
0.97
7.3
Channel
3260 0.069 Z Mtn. Stream
0.42
12.4 Channel
1035 0.010 R Riprap
0.92
4.3
Channel
1460 0.042 Z Mtn. Stream
0.66
2.6 Channel
1075 0.031 R Riprap
0.69
3.1
Channel
1300 0.077 Z Mtn. Stream
0.36
2.6
Channel
1950 0.092 Z Mtn. Stream
0.41
3.3 Channel
1880 0.064 Z Mtn. Stream
0.20
12.2
Channel
1800 0.082 Z Mtn. Stream
0.21
5.0 Channel
260 0.059 R Riprap
0.32
0.9
Channel
1100 0.159 Z Mtn. Stream
0.35
1.6 Channel
1250 0.089 R Riprap
0.38
3.1
Notes:
(1) Refer to Attachment A for Roughness Condition descriptions and Tc Coeffiecients.
(2) PLNT, Pit I, and Pit II Subbasins times of concentration assumed to be 10 min
Flow Segment 3
Flow Segment 4
Roughness Condition
(1)
Roughness Condition
(1)
J:\11JOBS\113-82323 Bear Lodge Mine\Surface Water\H&H calculations\Bear Lodge H&H v4.11Rev E.xlsm
Page 2 of 2
Golder Associates
2/13/2014
