Fish Passage Site 20401286

Coordinates (dec. deg.): 61.52482°, -149.57159°
Legal Description: S017N002W35
Region: South Central
Road Name: Trapline Drive

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #: 247-50-10300-2012
Stream Name: Cottonwood Slough

Elevation:

Site Comments: This culvert is under the road. It's at a right anlgle to #134 - 15' away from #134

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 MSB23-MS022

Project Supervisor: Michael Mazzacavallo, Alaska Department of Fish and Game — Anchorage, AK
Observers: Michael Mazzacavallo, Kat Leavitt, Beth Evers

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. None of this type

Comments: Fish spotted jumping downstream. Culvert is sagging slightly on left side, inside. Inlet has large bank of sediment build up on right side.

Culvert Measurements

ID: 1 Structure Type: Pipe-arch (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 49.82
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 3.0
Condition Rating(1-5): 3
Approach Angle: 80.0
Sedimentation At Inlet: Yes
Inlet Substrate: Gravel
Outlet Substrate: Silt/Clay
InletOutlet
Width(ft):5.8 5.9
Height(ft):3.0 3.1
Apron Length(ft):
Water Depth(ft): 0.77
Rustline Height(ft):1.8
Substrate Depth(ft):0.7 0.65
Backwatered?: No
Baffles Present: No
Embedded?: No
Embedded Depth(ft): 0.7
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.82
Culvert Gradient: 0.12%
Max Slope:
Max Slope Length:
 

Comments: Inlet is fed by small culvert in a ditch. The channel is ditch0, no constriction ratio.
  Culvert Observations:
  1. None of this type

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:SandSand
Subdominant:OrganicOrganic
Stream Slope(deg.):0.63
Stream Flow Stage:Medium

No stream width data available.

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 100.48
U/S Water Surface Elev 0.00 94.87
U/S Thalweg 0.00 94.03
Inlet Culvert Invert 11.00 94.04
U/S Water Surface Elev 11.00 94.81
Inlet Culvert Top 11.00 97.20
D/S Water Surface Elev 60.82 94.82
Outlet Culvert Top 60.82 97.14
Outlet Invert 60.82 93.85
D/S Thalweg 74.82 93.95
D/S Water Surface Elev 74.82 94.80
D/S Water Surface Elev 138.82 94.62
D/S Thalweg 138.82 93.35
D/S Thalweg 164.82 93.51
D/S Water Surface Elev 164.82 94.52

Notes:

  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): 3.06
Channel Type: Main Channel (>50% of water flow)
 
Gear Type: Minnow Trap (B) Trap Duration(h): 3.06
Channel Type: Main Channel (>50% of water flow)

Fish Observations

Species: juvenile coho salmon Life History: Anadromous
Total Fish Observed: 11 Fish Measured: 11 Fork Lengths (mm) Min: 70 Max: 179 Mean: 104
Collected/Observed by Gear Type: Upstream Minnow Trap (5)  Downstream Minnow Trap (6)  
 
Species: juvenile rainbow trout Life History: Resident
Total Fish Observed: 2 Fish Measured: 2 Fork Lengths (mm) Min: 54 Max: 65 Mean: 59
Collected/Observed by Gear Type: Upstream Minnow Trap (1)  Downstream Minnow Trap (1)  
 
Species: juvenile/adult Dolly Varden Life History: Resident
Total Fish Observed: 1 Fish Measured: 1 Fork Lengths (mm) Min: 137 Max: 137 Mean: 137
Collected/Observed by Gear Type: Upstream Minnow Trap (1)  

Questions or comments about this report can be directed to dfg.dsf.webmaster@alaska.gov