Fish Passage Site 20601527

Coordinates (dec. deg.): 61.06325°, -151.36644°
Legal Description: S011N012W11
Region: South Central
Road Name: Tyonek Timber Road

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


Site Comments: AKA Roberts Creek

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-TY001

Project Supervisor: Gillian O'Doherty, ADFG
Observers: Mark Eisenman, Robert Pype

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year: 2015

Site Observations:

  1. None of this type

Comments: Site looks good. Upstream root wads appear to have been set too high and are starting to be under cut. No traps set, no fish observed. Long profile used the site's permanent benchmark for elevations

Culvert Measurements

ID: 1 Structure Type: Open-bottom arch (Structural steel plate) Fish Passage Rating: Green
Length(ft): 45.4
Inlet Type: Headwall
Outlet Type: Headwall
Corrugation Depth(in.): 3.5
Corrugation Width(in.): 6.0
Condition Rating(1-5): 5
Approach Angle: 7.0
Sedimentation At Inlet: No
Inlet Substrate: Cobble
Outlet Substrate: Cobble
Width(ft):26.0 26.0
Height(ft):11.7 10.8
Apron Length(ft):
Water Depth(ft): 1.04
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: 1.89%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type

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 113.34
D/S Thalweg (End of constructed outlet reach) 0.00 95.72
D/S Water Surface Elev 0.00 97.16
D/S Thalweg (Middle of constructed outlet reach) 65.00 97.02
D/S Water Surface Elev 65.00 98.09
Outlet Invert (On substrate) 115.00 97.60
D/S Water Surface Elev 115.00 98.64
Outlet Culvert Top 115.00 108.81
Inlet Culvert Top 159.40 109.67
Inlet Culvert Invert (On substrate, 1st resting habitat) 159.40 98.01
U/S Water Surface Elev 159.40 98.89
U/S Thalweg (Middle of upstream constructed reach) 254.40 99.42
U/S Water Surface Elev 254.40 100.17
U/S Thalweg (End of upstream constructed reach) 339.40 100.79
U/S Water Surface Elev 339.40 102.17


  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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