Fish Passage Site 20601535

Coordinates (dec. deg.): 61.06654°, -151.32612°
Legal Description: S011N012W01
Region: South Central
Road Name: Tyonek Timber Road

Datum: NAD83
Quad Name / ITM: Tyonek A-4
AWC Stream #:
Stream Name: Unnamed


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: Mark Eisenman, Gillian O'Doherty, Robert Pype

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: Yes

Step Pools: No
Construction Year:

Site Observations:

  1. Other, including vibrations, cavitation, etc.

Comments: A grate has been added to the inlet since the original survey in 2002 and the outlet perch as been removed due to beaver damming downstream. The upstream grate was clogged with horsetail.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Non-corrugated metal) Fish Passage Rating: Gray
Length(ft): 32.0
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.):
Corrugation Width(in.):
Condition Rating(1-5): 2
Approach Angle: 0.0
Sedimentation At Inlet: Yes
Inlet Substrate:
Outlet Substrate:
Width(ft):1.85 1.6
Height(ft):1.8 1.3
Apron Length(ft):
Water Depth(ft): 1.38
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?: Yes
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: -0.06%
Max Slope:
Max Slope Length:

Comments: Beaver grate at inlet. Outlet is submerged. Ponded upstream and downstream from culvert. Water surface elevations equal upstream and downstream. Site is backwatered, but inlet grate causes a barrier. Overnight trapping caught no fish.

  Culvert Observations:
  1. Other, including vibrations, cavitation, etc.

Stream Measurements

Stream SubstratesUpstreamDownstream
Stream Slope(deg.):
Stream Flow Stage:Medium

No stream width data available.


Locator ID Culvert
Distance (ft)1
Distance From
Crossing (ft)2
Elevation (ft)
Road Elev 100.43
D/S Water Surface Elev 0.00 99.18
Outlet Invert 0.00 97.80
Outlet Culvert Top 0.00 99.16
Inlet Culvert Top 31.50 99.78
U/S Water Surface Elev 32.00 99.18
Inlet Culvert Invert (On substrate in front of beaver grate) 32.00 97.91


  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): 24.0
Comments: Trap set about 35 feet downstream. No fish caught

Fish Observations

No fish observations occurred during this survey.

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