Fish Passage Site 20401308

Coordinates (dec. deg.): 61.60934°, -149.29179°
Legal Description: S018N001E33
Region: South Central
Road Name: Trail near Palmer Elks

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

Elevation:

Site Comments: Footbridge installed and new photos taking on 8/31/11.

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-CT160

Observers: Edward Weiss, Joe Conner

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools:
Construction Year:


Site Observations:

  1. Hydraulic flows exceeded capacity
  2. Inlet perch

Comments: 2 half pipes form 1 pipe;upper end left culvert damaged collapsed fallen inlet blocking flow-most flow jetting thru right culvert;culverts need to come out-no longer have an purpose-old farm road.

Culvert Measurements

ID: 1 Structure Type: Closed-bottom arch (Strutural Metal Plate) Fish Passage Rating: Red
 
Length(ft): 22.8
Inlet Type: Mitered
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: Gravel
InletOutlet
Width(ft):2.8 3.0
Height(ft):3.2 2.7
Apron Length(ft):
Water Depth(ft):0.9 1.0
Rustline Height(ft):
Substrate Depth(ft):0.0 0.3
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type: At Stream Grade
Constriction Ratio: 0.32
Culvert Gradient:
Max Slope:
Max Slope Length:
ID: 2 Structure Type: Closed-bottom arch (Strutural Metal Plate) Fish Passage Rating: Red
 
Length(ft): 20.3
Inlet Type: Mitered
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: Gravel
InletOutlet
Width(ft):3.0 3.0
Height(ft):3.0 2.4
Apron Length(ft):
Water Depth(ft):1.5 1.0
Rustline Height(ft):
Substrate Depth(ft):0.0 0.6
Backwatered?:
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type: At Stream Grade
Constriction Ratio: 0.32
Culvert Gradient: 0.39%
Max Slope:
Max Slope Length:

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 50.0 20.20
Downstream ordinary high water 81.0 20.60
Upstream ordinary high water 50.0 21.00
Upstream ordinary high water 95.0 14.80

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Inlet Culvert Top 2 92.70
Inlet Culvert Top 1 93.10
Outlet Culvert Top 2 92.17
Outlet Culvert Top 1 92.35
D/S Thalweg 0.00 81.0 87.96
D/S Thalweg 31.00 50.0 88.64
D/S Tailcrest or 1st Thalweg 70.00 11.0 90.11
OHW Left Bank 72.00 9.0 89.66
D/S Thalweg 74.00 7.0 89.42
Outlet Invert 1 81.00 0.0 89.66
Outlet Thalweg 1 81.00 0.0 89.66
Outlet Invert 2 81.00 0.0 89.71
Outlet Thalweg 2 81.00 0.0 89.73
Road Elev 91.50 94.07
Road Elev 91.50 94.67
Inlet Culvert Invert 2 102.00 0.0 89.79
Inlet Thalweg 2 102.00 0.0 89.92
Inlet Thalweg 1 102.00 0.0 90.57
U/S Thalweg 152.00 50.0 91.33
U/S Thalweg 197.00 95.0 92.66

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 upstream and downstream of culvert

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