SURFACE-WATER FIELD TECHNIQUES

South Fork Clearwater River near Grangeville, Idaho - n = 0.051

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Site Description

 

Station name	South Fork Clearwater River near Grangeville, Idaho
Station number	13-3380
Gage location	Lat 4555', long 11601', in SE 1/4 NW 1/4 sec. 30, T. 30 N., R. 4 E., on right bank downstream from powerhouse of Washington Water Power Co.,6 miles east of Grangeville. Section 1 is about 1.8 miles upstream from gage.
Drainage area	865 sq mi
Date of flood	May 29, 1948
Gage height	12.50 ft at gage: 30.85 ft at section 1
Peak discharge	12,600 cfs
Computed roughness coefficient	Manning n = 0.051
Description of channel	Bed consists of rocks and boulders; d50 = 250 mm, d84 = 440 mm. Banks are mostly boulders and have trees and brush along top.

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	1,326	134	9.90	9.40	9.50	.......	.....
2	1,310	143	9.16	8.68	9.62	255	1.40
3	1,434	181	7.92	7.71	8.79	295	1.45
4	1,267	148	8.56	8.23	9.94	357	2.85

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