Fish Passage Site 20401301

Coordinates (dec. deg.): 61.53214°, -149.52786°
Legal Description: S017N001W30
Region: South Central
Road Name: West Riverdell Drive

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-CT152

Observers: Edward Weiss, Joe Conner, Doug Hill

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools:
Construction Year:


Site Observations:

  1. Hydraulic flows exceeded capacity

Comments: Downstream reach is braided w/lots of woody debris, channel breaks apart a lot, ice problems in winter.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Strutural Metal Plate) Fish Passage Rating: Red
 
Length(ft): 51.0
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: Gravel
Outlet Substrate: Cobble
InletOutlet
Width(ft):5.0 5.0
Height(ft):5.0 5.0
Apron Length(ft):
Water Depth(ft):1.9 1.4
Rustline Height(ft):
Substrate Depth(ft):0.0 0.0
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.31
Culvert Gradient: -0.18%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type
ID: 2 Structure Type: Pipe-arch (Corrugated Metal) Fish Passage Rating: Red
 
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: Gravel
Outlet Substrate: Cobble
InletOutlet
Width(ft):4.0 4.2
Height(ft):2.3 2.7
Apron Length(ft):
Water Depth(ft):0.6 0.9
Rustline Height(ft):
Substrate Depth(ft):1.7 0.0
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.31
Culvert Gradient: 0.74%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:
Subdominant:
Stream Slope(deg.):
Stream Flow Stage:
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Downstream ordinary high water 129.0 44.00
Upstream ordinary high water 50.0 30.00
Upstream ordinary high water 125.0 28.70

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
U/S Thalweg 89.91
Outlet Culvert Top 2 92.09
Inlet Culvert Top 2 92.46
Inlet Culvert Top 1 94.01
Outlet Culvert Top 1 94.08
D/S Thalweg (Channel split --main flow) 0.00 129.0 86.92
D/S Thalweg 76.00 53.0 88.31
D/S Tailcrest or 1st Thalweg 117.00 12.0 89.86
OHW Left Bank 124.00 5.0 89.33
D/S Thalweg 127.75 1.25 89.00
Outlet Invert 1 129.00 0.0 89.05
Outlet Invert 2 129.00 0.0 89.36
Outlet Thalweg 1 129.00 0.0 88.92
Outlet Thalweg 2 129.00 0.0 89.24
Road Elev 154.00 95.22
Road Elev 154.00 95.40
Inlet Culvert Invert 2 179.00 0.0 90.13
Inlet Thalweg 2 179.00 0.0 90.24
Inlet Culvert Invert 1 179.00 0.0 88.96
Inlet Thalweg 1 179.00 0.0 89.19
U/S Thalweg 304.00 125.0 90.84

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

No fish sampling occurred during this survey.

Fish Observations

No fish observations occurred during this survey.

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