Fish Passage Site 20401303

Coordinates (dec. deg.): 61.55406°, -149.48825°
Legal Description: S017N001W20
Region: South Central
Road Name: Edlund

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

Elevation:

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.

Survey MSCS1-CT154

Observers: Joe Conner, Edward Weiss, Nathan Pannkuk

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Comments: Ponded upstream and 100' downstream Ponded above & 100' below, Immediately below culvert is small cobble-gradually going to fine gravel @ top of plume/start of pond. Technically Red but likely passes fihs at most flows so rated as Gray.

Culvert Measurements

ID: 1 Structure Type: Open-bottom arch (Strutural Metal Plate) Fish Passage Rating: Gray
 
Length(ft): 50.0
Inlet Type: Projecting
Outlet Type:
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.67
Condition Rating(1-5):
Approach Angle:
Sedimentation At Inlet:
Inlet Substrate: Sand
Outlet Substrate: Cobble
InletOutlet
Width(ft):9.0 9.2
Height(ft):4.5 5.1
Apron Length(ft):
Water Depth(ft):0.85 0.85
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type:
Constriction Ratio:
Culvert Gradient: 0.86%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:SandCobble
Subdominant:
Stream Slope(deg.):
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Downstream ordinary high water 50.0 62.00
Downstream ordinary high water 94.0 64.00
Upstream ordinary high water 55.0 95.00

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Outlet Culvert Top 1 94.31
Inlet Culvert Top 1 94.74
D/S Thalweg (Base of gravel plume) 0.00 104.5 87.05
D/S Thalweg 10.50 94.0 88.78
D/S Thalweg 54.50 50.0 88.79
Max Pool Depth 97.50 7.0 89.47
Outlet Thalweg 1 104.50 0.0 89.81
Outlet Invert 1 104.50 0.0 89.13
Road Elev 129.50 95.86
Road Elev 129.50 96.10
Inlet Culvert Invert 1 154.50 0.0 90.00
Inlet Thalweg 1 154.50 0.0 90.00
U/S Thalweg 1 161.50 7.0 89.38
U/S Thalweg 209.50 55.0 91.90

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: Visual Observation, Ground (C)

Fish Observations

Species: adult coho salmon Life History: Anadromous (Suspected Spawning)
Total Fish Observed: Fish Measured: Fork Lengths (mm) Min: Max: Mean:
Collected/Observed by Gear Type: Upstream Visual Observation, Ground ()  
Comments: Adult coho observed upstream and downstream of culvert

Photos

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