Fish Passage Site 40601679

Coordinates (dec. deg.): 67.73750°, -149.75487°
Legal Description: F034N010W26
Region: Interior
Road Name: Dalton Highway

Datum: NAD83
Quad Name / ITM: Chandalar C-6
AWC Stream #:
Stream Name: Snowden Creek

Elevation:

Site Comments: pipeline crossing just downstream

Survey Date: Aug 22, 2010

Survey EDS10-DAL19

Observers: Gillian O'Doherty, Ben Histand

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Culvert gradient red
  2. Culvert gradient gray

Comments: Very swift flow through pipe 2; u/s ws gradient is 2.0%; d/s crossing @ pipeline looks better than this site

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Red
 
Length(ft): 80.5
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.67
Condition Rating(1-5): 3
Approach Angle: 1.0
Sedimentation At Inlet: Yes
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):4.9 4.9
Height(ft):4.8 4.9
Apron Length(ft):
Water Depth(ft): 0.29
Rustline Height(ft):0.0
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: 2.16%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient red
ID: 2 Structure Type: Open-bottom arch (Structural steel plate) Fish Passage Rating: Gray
 
Length(ft): 71.0
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.0
Corrugation Width(in.): 6.0
Condition Rating(1-5): 4
Approach Angle: 1.0
Sedimentation At Inlet: Yes
Inlet Substrate: Cobble
Outlet Substrate: Cobble
InletOutlet
Width(ft):11.8 11.8
Height(ft):5.9 5.6
Apron Length(ft):
Water Depth(ft): 1.3
Rustline Height(ft):1.7
Substrate Depth(ft):
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: 0.73%
Max Slope:
Max Slope Length:
 

Comments: embedded depth unknown it is possible that this is an embedded pipe arch and not an AO.
  Culvert Observations:
  1. Culvert gradient gray

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:CobbleCobble
Subdominant:GravelGravel
Stream Slope(deg.):2
Stream Flow Stage:Medium

No stream width data available.

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 102.24
D/S Tailcrest or 1st Thalweg 1 0.00 93.13
D/S Water Surface Elev (channel from pipe 1 - not main channel) 1 0.00 93.67
Max Pool Depth (outlet pool for pipe 1) 1 21.00 91.29
Outlet Pool Water Elev (just outside outlet) 2 29.00 93.94
D/S Water Surface Elev (ws @ outlet) 2 30.00 93.99
Outlet Culvert Top 2 30.00 93.99
Outlet Culvert Top 1 30.00 92.64
Outlet Invert (on subs) 2 30.00 92.64
Outlet Pool Water Elev ((TWS)) 1 30.00 93.68
Outlet Invert (on subs) 1 30.00 98.35
Inlet Culvert Top 2 101.00 98.98
Inlet Culvert Invert (on subs) 2 101.00 92.75
U/S Headwater (@ inlet pipe 2) 2 101.00 94.40
Inlet Culvert Invert 1 110.50 95.13
U/S Headwater (same @ ws @ inlet pipe 1) 1 110.50 95.44
Inlet Culvert Top 1 110.50 100.01
U/S Water Surface Elev 146.00 95.97
U/S Thalweg (1st bend) 146.00 94.93
U/S Thalweg (top steep section) 247.00 97.43
U/S Water Surface Elev 247.00 98.18
U/S Water Surface Elev 342.00 100.38
U/S Thalweg (@ braid) 342.00 99.47
U/S Thalweg (no braids, all of stream in one channel; bottom steep section) 400.00 99.37

Notes:

  1. River distance is measured continuously throughout the survey reach along the thalweg of the stream.
  2. Measured from each end of the crossing along the thalweg of the stream.

Fish Sampling Efforts

No fish sampling occurred during this survey.

Fish Observations

No fish observations occurred during this survey.

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