SURFACE-WATER FIELD TECHNIQUES

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Rock Creek Canal near Darby, Montana - n = 0.060

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Site Description

 

Station name	Rock Creek Canal near Darby, Montana
Station number	12-2455
Gage 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 gage.
Date of flood	September 23, 1948
Gage height	3.34 ft at gage; 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.

Introduction Page || Site Description || Reach Properties
Plan Sketch and Cross Sections || Site Photos

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Reach Properties

 

Section	Area (sq ft)	Top Width (ft.)	Mean depth (ft)	Hydraulic radius (ft)	Mean velocity (ft per sec)	Lenght (ft) between sections	Fall (ft) between sections
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

Introduction Page || Site Description || Reach Properties
Plan Sketch and Cross Sections || Site Photos

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Plan Sketch and Cross Sections

Introduction Page|| Site Description || Reach Properties
Plan Sketch and Cross Sections || Site Photos

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Site Photos