SURFACE-WATER FIELD TECHNIQUES

Middle Fork Flathead River near Essex, Montana - n = 0.041

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Site Description

 

Station name	Middle Fork Flathead River near Essex, Montana
Station number	12-3557
Gage location	Lat 48°10'20'', long 113°32'40'', near center of sec. 19, T. 28 N., R. 15 W., on right bank 0.25 mile downstream from Spruce Park Cabin, 1 mile downstream from Charlie Creek, and 7.5 miles southeast of Essex. Section 1 is 600 ft upstream from gage.
Drainage area	408 sq mi.
Date of flood	May 22, 1948
Gage height	10.95 ft at gage: 14.21 ft at section 1.
Peak discharge	14,500 cfs
Computed roughness coefficient	Manning n = 0.041
Description of channel	Bed consists of boulders; d50 = 142 mm, d84 = 285 mm.Banks are composed of gravel and boulders, and have trees and brush along the tops.

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	1,745	208	8.39	8.23	8.31	.......	.....
2	1,658	187	8.87	8.73	8.75	291	1.07
3	1,504	150	10.03	9.35	9.64	109	.64
4	1,472	172	8.56	8.37	9.85	221	.88
5	1,601	191	8.38	8.22	9.06	346	.87

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