Fish Passage Site 20100612

Coordinates (dec. deg.): 62.56504°, -143.43504°
Legal Description: C009N011E18
Region: South Central
Road Name: Nabesna Road

Datum: NAD83
Quad Name / ITM: Nabesna C-5
AWC Stream #:
Stream Name: Rock Creek


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.


Project Supervisor: Gillian O'Doherty, ADFG
Observers: Andrew Kastning

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:

Site Observations:

  1. Culvert gradient gray
  2. Outfall height red
  3. Constriction ratio red
  4. Inlet perch
  5. Road bank erosion

Comments: Site accessed and submitted by the Copper River Watershed Project. Large amount of bedload. Flashy mountain stream. Large outwash plain downstream of crossing.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Red
Length(ft): 101.1
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 4
Approach Angle: 25.0
Sedimentation At Inlet: Yes
Inlet Substrate: Gravel
Outlet Substrate: None
Width(ft):5.6 5.6
Height(ft):5.58 5.9
Apron Length(ft):
Water Depth(ft): 0.64
Rustline Height(ft):1.75
Substrate Depth(ft):0.62 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.99
Outfall Type: Free Fall on To Rip Rap
Constriction Ratio: 0.4
Culvert Gradient: 0.77%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient gray
  2. Outfall height red
  3. Constriction ratio red
  4. Inlet perch
  5. Road bank erosion

Stream Measurements

Stream SubstratesUpstreamDownstream
Stream Slope(deg.):2
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)
Width (ft)
Downstream ordinary high water 12.80
Downstream ordinary high water 37.10
Downstream ordinary high water 34.10
Upstream ordinary high water 10.90
Upstream ordinary high water 14.60
Upstream ordinary high water 16.30


Locator ID Culvert
Distance (ft)1
Distance From
Crossing (ft)2
Elevation (ft)
Road Elev 100.64
D/S Grade Ctrl (Thalweg) 0.00 87.36
D/S Water Surface Elev 0.00 88.18
D/S Grade Ctrl (Thalweg) 100.90 88.93
D/S Water Surface Elev 100.90 89.35
D/S Grade Ctrl (Thalweg) 172.50 90.29
D/S Water Surface Elev 172.50 90.69
D/S Tailcrest or 1st Thalweg 242.00 91.79
D/S Water Surface Elev 242.00 92.36
Outlet Pool Water Elev 250.30 92.43
Max Pool Depth 250.30 90.29
Outlet Invert 256.00 92.78
D/S Water Surface Elev 256.00 93.42
Outlet Culvert Top 256.00 98.68
U/S Water Surface Elev 357.10 95.10
Inlet Culvert Top 357.10 99.46
Inlet Culvert Invert 357.10 93.88
U/S Grade Ctrl (Thalweg) 363.50 94.97
U/S Water Surface Elev 363.50 95.55
U/S Water Surface Elev 381.50 96.11
U/S Grade Ctrl (Thalweg) 381.50 95.50
U/S Grade Ctrl (Thalweg) 475.70 98.02
U/S Water Surface Elev 475.70 98.60
U/S Grade Ctrl (Thalweg) 523.10 98.88
U/S Water Surface Elev 523.10 99.44


  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: Minnow Trap (A) Trap Duration(h): 12.0
Comments: 3 traps set upstream, no fish caught or observed.
Gear Type: Minnow Trap (B) Trap Duration(h): 12.0
Comments: 2 traps set downstream, no fish caught or observed.

Fish Observations

No fish observations occurred during this survey.

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