Fish Passage Site 20401293

Coordinates (dec. deg.): 61.53077°, -149.51842°
Legal Description: S017N001W30
Region: South Central
Road Name: Harness

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #: 247-50-10300-2022
Stream Name: Cottonwood Creek tributary

Elevation:

Site Comments: Downstream channelized through yard, lawn, down to waterline.

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-CT142

Observers: Edward Weiss, Doug Hill

Overall Fish Passage Rating:

Tidal: No
Backwatered: No

Step Pools:
Construction Year:


Comments: Dwnstrm channelized thru yard, lawn, down to waterline; Left Culv larger of 2 is overlflow trickling; No real channel below-flows thru lawn into main channel;land owner complains of icing/glaciering

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated Metal) Fish Passage Rating:
 
Length(ft): 52.5
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: Silt/Clay
Outlet Substrate: Silt/Clay
InletOutlet
Width(ft):2.46 2.43
Height(ft):2.55 2.0
Apron Length(ft):
Water Depth(ft):2.1 1.8
Rustline Height(ft):
Substrate Depth(ft):0.1 0.43
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type:
Constriction Ratio: 1.02
Culvert Gradient: -0.17%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Other, including vibrations, cavitation, etc.
ID: 2 Structure Type: Circular pipe (Corrugated Metal) Fish Passage Rating:
 
Length(ft): 50.5
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: Silt/Clay
Outlet Substrate: Gravel
InletOutlet
Width(ft):2.4 2.0
Height(ft):1.94 1.9
Apron Length(ft):
Water Depth(ft):0.8 3.7
Rustline Height(ft):
Substrate Depth(ft):0.0 0.1
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type:
Constriction Ratio: 1.02
Culvert Gradient: -0.02%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. None of this type

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:
Subdominant:
Stream Slope(deg.):
Stream Flow Stage:High
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Downstream ordinary high water 50.0 3.00
Downstream ordinary high water 100.0 3.30
Upstream ordinary high water 50.0 4.00
Upstream ordinary high water 100.0 5.50

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
D/S Thalweg 90.28
D/S Thalweg 90.33
U/S Thalweg 90.94
U/S Thalweg 91.24
Outlet Culvert Top 1 92.85
Inlet Culvert Top 1 92.86
Outlet Culvert Top 2 93.51
Inlet Culvert Top 2 93.97
Outlet Invert 1 0.00 0.0 90.87
Outlet Thalweg 1 0.00 0.0 90.91
Outlet Invert 2 0.00 0.0 91.41
Outlet Thalweg 2 0.00 0.0 91.41
Road Elev 25.50 95.66
Road Elev 25.50 95.68
Inlet Culvert Invert 2 51.00 0.0 91.40
Inlet Thalweg 2 51.00 0.0 91.40
Inlet Culvert Invert 1 51.00 0.0 90.78
Inlet Thalweg 1 51.00 0.0 90.78

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): 1

Fish Observations

Species: juvenile/adult Dolly Varden Life History: Unknown
Total Fish Observed: 1 Fish Measured: 1 Fork Lengths (mm) Min: 91 Max: 91 Mean: 91
Collected/Observed by Gear Type: Upstream Minnow Trap (1)  
 
Species: juvenile coho salmon Life History: Anadromous
Total Fish Observed: 9 Fish Measured: 5 Fork Lengths (mm) Min: 59 Max: 100 Mean: 87
Collected/Observed by Gear Type: Upstream Minnow Trap (9)  

Photos

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