Fish Passage Site 20501182

Coordinates (dec. deg.): 61.70733°, -150.08525°
Legal Description: S019N005W25
Region: South Central
Road Name: Crystal Lake Road

Datum: WGS84
Quad Name / ITM: Tyonek C-1
AWC Stream #:
Stream Name: Rainbow Lake to Long Lake connection


Site Comments: Rainbow Lake to Long Lake connection

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

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year: 2015

Site Observations:

  1. None of this type

Comments: Culvert replaced July 2015. Nice constructed banks along sides of culvert. All construction sediment control has been removed and banks are starting to green up nicely.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
Length(ft): 92.9
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 5
Approach Angle:
Sedimentation At Inlet: No
Inlet Substrate:
Outlet Substrate:
Width(ft):7.9 8.0
Height(ft):6.5 5.3
Apron Length(ft):
Water Depth(ft): 0.45
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Embedded Depth(ft): 1.5
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: 1.63%
Max Slope:
Max Slope Length:

Comments: Stream gradient cal

Stream Measurements

Stream SubstratesUpstreamDownstream
Stream Slope(deg.):1.75
Stream Flow Stage:Low

No stream width data available.


Locator ID Culvert
Distance (ft)1
Distance From
Crossing (ft)2
Elevation (ft)
Road Elev 103.99
D/S Thalweg 0.00 92.71
D/S Water Surface Elev 0.00 93.23
D/S Grade Ctrl (Thalweg) (Gravel Bar) 38.00 93.29
D/S Water Surface Elev 38.00 93.54
D/S Thalweg (Middle of outlet riffle) 62.00 93.14
D/S Water Surface Elev 62.00 93.58
Outlet Invert (On substrate) 83.00 93.18
D/S Water Surface Elev 83.00 93.63
Outlet Culvert Top 83.00 98.52
Inlet Culvert Top 175.90 100.03
Inlet Culvert Invert (On substrate, 1st resting) 175.90 94.10
U/S Water Surface Elev 175.90 94.62
U/S Thalweg (Upstream riffle) 204.90 95.60
U/S Water Surface Elev 204.90 95.94
U/S Thalweg (Middle of riffle) 254.90 96.74
U/S Water Surface Elev 254.90 97.51
U/S Grade Ctrl (Thalweg) (Old Beaver dam) 289.90 98.01
U/S Water Surface Elev 289.90 98.61
U/S Thalweg (Above old beaver dam) 375.90 97.36
U/S Water Surface Elev 375.90 98.60


  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.

Questions or comments about this report can be directed to