Fish Passage Site 20400244

Coordinates (dec. deg.): 61.08694°, -149.82243°
Legal Description: S012N003W33
Region: South Central
Road Name: Porcupine Trail

Datum: NAD83
Quad Name / ITM: Anchorage A-8
AWC Stream #:
Stream Name: Rabbit Creek

Elevation:

Site Comments: None

Multiple surveys have been conducted at this site — click on the drop down
arrow to the right of the survey date below to choose a different report for this site.

Survey UPDATE-POT01

Project Supervisor: Gillian O'Doherty, ADFG
Observers: Gillian O'Doherty, Ben Histand, Heidi Zimmer

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Culvert gradient red
  2. Outfall height red
  3. Constriction ratio red
  4. Compound gradient in pipe
  5. Mechanical damage or joints parting

Comments: Fish carcasses observed below culvert, probably pinks. Large rocks in pipe 2 create hydraulic jump.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Reinforced concrete) Fish Passage Rating: Red
 
Length(ft): 21.0
Inlet Type: Headwall
Outlet Type: Headwall
Corrugation Depth(in.):
Corrugation Width(in.):
Condition Rating(1-5): 5
Approach Angle: 53.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):4.0 4.0
Height(ft):4.0 4.0
Apron Length(ft):
Water Depth(ft): 0.0
Rustline Height(ft):
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 1.0
Outfall Type: Free Fall In To Pool
Constriction Ratio: 0.48
Culvert Gradient: 3.57%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient red
  2. Outfall height red
  3. Constriction ratio red
  4. Mechanical damage or joints parting
ID: 2 Structure Type: Circular pipe (Structural steel plate) Fish Passage Rating: Red
 
Length(ft): 21.2
Inlet Type: Headwall
Outlet Type: Headwall
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.66
Condition Rating(1-5): 2
Approach Angle: 53.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):4.0 4.0
Height(ft):3.5 4.0
Apron Length(ft):
Water Depth(ft): 0.4
Rustline Height(ft):2.4
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.88
Outfall Type: Free Fall In To Pool
Constriction Ratio: 0.48
Culvert Gradient: 0.42%
Max Slope:
Max Slope Length:
 

Comments: Large rocks in culvert create hydraulic jump. (CG)

  Culvert Observations:
  1. Culvert gradient gray
  2. Outfall height red
  3. Constriction ratio red
  4. Mechanical damage or joints parting
  5. Compound gradient in pipe
ID: 3 Structure Type: Circular pipe (Structural steel plate) Fish Passage Rating: Red
 
Length(ft): 20.5
Inlet Type: Headwall
Outlet Type: Headwall
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.66
Condition Rating(1-5): 2
Approach Angle: 53.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):4.3 3.9
Height(ft):3.7 4.1
Apron Length(ft):
Water Depth(ft): 0.64
Rustline Height(ft):2.2
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.47
Outfall Type: Free Fall In To Pool
Constriction Ratio: 0.48
Culvert Gradient: 2.63%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient red
  2. Constriction ratio red
  3. Outfall height red
  4. Mechanical damage or joints parting

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:CobbleCobble
Subdominant:
Stream Slope(deg.):
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)
Stream
Width (ft)
Upstream ordinary high water 55.0 14.50
Upstream ordinary high water 90.0 15.50
Upstream ordinary high water 135.0 13.00

Elevations

Locator ID Culvert
Number
River
Distance (ft)1
Distance From
Crossing (ft)2
Relative
Elevation (ft)
Road Elev 99.05
D/S Thalweg 0.00 89.99
D/S Water Surface Elev 0.00 90.37
D/S Tailcrest or 1st Thalweg (TWC) 15.00 91.13
D/S Water Surface Elev 15.00 91.74
Misc. (Bottom of outlet pool scour hole from pipe 3) 3 35.80 89.37
Misc. (Bottom of outlet pool scour hole from pipe 2.) 2 36.40 89.17
Misc. (Profile directly below pipe 3 outlet) 3 41.00 90.26
Outlet Invert (Bottom of pipe) 3 41.00 91.57
Misc. (Profile directly bellow pipe 2 outlet.) 2 41.00 90.62
Outlet Invert 2 41.00 92.22
Outlet Invert 1 41.00 92.74
D/S Water Surface Elev (Tailwater surface of outlet pool below pipes 2 and 3.) 41.00 91.74
Inlet Culvert Invert 1 62.00 93.49
U/S Headwater 1 62.00 93.36
Inlet Culvert Invert 2 62.00 92.13
U/S Headwater 2 62.00 93.21
Inlet Culvert Invert 3 62.00 92.11
U/S Headwater 3 62.00 93.10
U/S Grade Ctrl (Thalweg) 107.00 94.80
U/S Water Surface Elev 107.00 95.44

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

Gear Type: Visual Observation, Ground (A)
Comments: Salmon carcasses observed below culverts, prossibly pinks.

Fish Observations

No fish observations occurred during this survey.

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