Fish Passage Site 20501462

Coordinates (dec. deg.): 62.00833°, -149.98599°
Legal Description: S022N004W10
Region: South Central
Road Name: Caswell Lakes Road

Datum: WGS84
Quad Name / ITM: Talkeetna Mts A-6
AWC Stream #: 247-41-10200-2190
Stream Name: Caswell 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: Mark Eisenman, Shane Hetzog

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year: 2014

Site Observations:

  1. None of this type

Comments: Replaced in 2014 with a fish friendly culvert. Culvert reassessed 9/25/18. Adult spawning Coho salmon observed upstream and downstream of crossing. Stream widens out about 360 feet upstream and then necks back down around 600 feet above crossing. Small rock weir upstream at old ATV crossing. Root wad and other bioengineering present upstream and downstream of crossing. Upstream gradient between 1.4 and 2.2%, downstream gradient under 1%.

Culvert Measurements

ID: 1 Structure Type: Box culvert (Structural aluminum plate) Fish Passage Rating: Green
Length(ft): 60.3
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.5
Corrugation Width(in.): 9.0
Condition Rating(1-5): 5
Approach Angle: 0.0
Sedimentation At Inlet: No
Inlet Substrate: Cobble
Outlet Substrate: Cobble
Width(ft):16.0 16.0
Height(ft):5.5 5.7
Apron Length(ft):
Water Depth(ft): 0.88
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 1.06
Culvert Gradient: 0.71%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type

Stream Measurements

Stream SubstratesUpstreamDownstream
Stream Slope(deg.):2.22
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)
Width (ft)
Upstream ordinary high water 107.0 14.50
Upstream ordinary high water 181.0 13.90
Upstream ordinary high water 600.0 17.00


Locator ID Culvert
Distance (ft)1
Distance From
Crossing (ft)2
Elevation (ft)
Road Elev 102.18
D/S Grade Ctrl (Thalweg) 0.00 93.74
D/S Water Surface Elev 0.00 94.11
D/S Thalweg (Above riffle in middle of glide) 12.00 92.98
D/S Water Surface Elev 12.00 94.16
D/S Thalweg 59.00 93.17
D/S Water Surface Elev 59.00 94.26
D/S Tailcrest or 1st Thalweg 88.00 93.69
D/S Water Surface Elev 88.00 94.26
Max Pool Depth 100.00 93.14
Outlet Pool Water Elev 100.00 94.28
Outlet Invert (On substrate) 114.00 93.46
D/S Water Surface Elev 114.00 94.34
Outlet Culvert Top 114.00 99.19
Inlet Culvert Top 174.30 99.62
Inlet Culvert Invert (On substrate) 174.30 93.89
U/S Water Surface Elev 174.30 94.65
U/S Grade Ctrl (Thalweg) (Rock wier at head of old ATV trail crossing) 210.30 94.64
U/S Water Surface Elev 210.30 95.30
U/S Thalweg (Max pool depth US of Rock wier) 225.30 94.34
U/S Water Surface Elev 225.30 95.36
U/S Grade Ctrl (Thalweg) (Stream gradient begin) 318.30 96.55
U/S Water Surface Elev 318.30 96.96
U/S Thalweg (max pool depth) 330.30 96.14
U/S Water Surface Elev 330.30 97.10
U/S Grade Ctrl (Thalweg) 399.30 98.14
U/S Water Surface Elev 399.30 98.40
U/S Thalweg (max pool depth) 412.30 97.44
U/S Water Surface Elev 412.30 98.50
U/S Grade Ctrl (Thalweg) (Stream gradient end) 508.30 99.27
U/S Water Surface Elev 508.30 99.57


  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: Adult spawning coho salmon observed upstream and downstream

Fish Observations

Species: adult spawning coho salmon Life History: Anadromous
Total Fish Observed: 20 Fish Measured: Fork Lengths (mm) Min: Max: Mean:
Collected/Observed by Gear Type: At Site Visual Observation, Ground (20)  

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