Rock Creek Canal near Darby, Montana - n = 0.060 (Source: U.S.G.S Water
Supply Paper 1849)
Site Description
Station name
Rock Creek Canal, near Darby, Montana
Station number
12-2455
Gauge location
Lat 46°04'40'', long 120°28'30'', in SW 1/4 sec. 28, T. 4 N., R. 21 W., on
downstream side of footbridge, 0.25 mile downstream from diversion dam, 1.5
miles downstream from Como Lake, and 4 miles northwest of Darby. Section 1 is
about 0.25 mile upstream from gauge.
Date of flood
September 23rd, 1948
Gauge height
3.34 ft at gauge; 15.33 ft at section 1
Peak discharge
138 cfs
Computed roughness coefficient
Manning n = 0.060
Description of channel
Bed and bank consist of boulders ; d50 = 210 mm, d84
= 375 mm.
Reach Properties
Section
Area(sq ft)
TopWidth(ft.)
Meandepth(ft)
Hydraulicradius(ft)
Meanvelocity(ft
per sec)
Length (ft)betweensections
Fall (ft)betweensections
1
30
26
1.15
1.07
4.60
.......
.....
2
31
25
1.24
1.19
4.45
45
1.25
3
39
24
1.62
1.56
3.54
50
1.36
4
30
25
1.20
1.25
4.60
50
1.02
5
32
25
1.28
1.28
4.31
50
.93
6
37
26
1.42
1.37
3.73
50
.78
7
32
24
1.33
1.28
4.31
50
.85
Plan Sketch and Cross Sections
Plan and cross sections, Rock Creek Canal near Darby,
Montana.
Site Photos
Photo 136: Downstream from above section 1, Rock Creek Canal near
Darby, Montana.
Photo 137: Downstream from above section 1, Rock Creek Canal
near Darby, Montana
