SURFACE-WATER FIELD TECHNIQUES

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Rock Creek near Darby, Montana - n = 0.075

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Site Description

 

Station name	Rock Creek near Darby, Montana
Station number	12-3450
Gage location	Lat 4604'10'', long 11413'20'', in SE 1/4 SE 1/4 sec. 29, T. 4 N., R. 21 W., on left  bank 0.6  mile downstream from Como Lake,  0.7  mile upstream from Rock Creek Canal, and 4 miles northwest of Darby. Section 1 is about 0.25 mile upstream from gage.
Drainage area	55.4  sq mi
Date of flood	May 27, 1948
Gage height	5.78  ft at gage; 23.85  ft  at section 1
Peak discharge	1,500  cfs
Computed roughness coefficient	Manning n = 0.075
Description of channel	Bed consists of  boulders; d50 = 220 mm, d84 = 415 mm. Banks are composed of boulders and have trees and brush.

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	214	51	4.20	3.96	7.01	.......	.....
2	203	54	3.76	3.50	7.39	79	2.65
3	134	43	3.12	2.91	11.19	47	2.45

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