SURFACE-WATER FIELD TECHNIQUES

Chiwawa River near Plain, Washington - n = 0.043

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Site Description

 

Station name	Chiwawa River near Plain, Washington
Station number	12-4565
Gage location	Lat 47°50'30'', long 120°39'40'', in SE 1/4 sec. 13, T. 27 N., R. 12 E., on right bank 0.5 mile upstream from Goose Creek, 6 miles north of Plain, 7 miles upstream from mouth, and 11 miles northeast of Chiwaukum. Section 1 is 90 ft downstream from gage.
Drainage area	170 sq mi
Date of flood	May 29, 1948
Gage height	9.17 ft at gage; 9.62 ft at section 1
Peak discharge	5,880 cfs
Computed roughness coefficient	Manning n = 0.043
Description of channel	Bed generally extends to bedrock throughout reach with cover of boulders as much as 11/2 ft in diameter in some places. Banks are mildly sloped and have trees along the 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	744	145	5.13	5.03	7.90	.......	.....
2	747	125	5.97	5.74	7.87	165	0.55
3	803	145	5.54	5.42	7.32	163	0.80
4	770	131	5.89	5.75	7.64	145	0.99

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