Fish Passage Site 20401300

Coordinates (dec. deg.): 61.52724°, -149.52698°
Legal Description: S017N001W31
Region: South Central
Road Name: Fairview Loop Road

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

Elevation:

Site Comments: ATV trails thru outlet area & over top of culvert.

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 MSB09-FVL01

Project Supervisor: Gillian O'Doherty, ADFG
Observers: Heidi Zimmer, Ben Histand

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: Yes

Step Pools:
Construction Year:


Site Observations:

  1. Constriction ratio gray
  2. Culvert is poorly aligned
  3. Compound gradient in pipe

Comments: Resurvey of MSCS1CT151. Visual observation of adult coho u/s and d/s, juv salmonids u/s. Inlet miter 8', outlet miter 6'.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 67.0
Inlet Type: Mitered
Outlet Type: Mitered
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 3
Approach Angle: 30.0
Sedimentation At Inlet: Yes
Inlet Substrate: Gravel
Outlet Substrate: Gravel
InletOutlet
Width(ft):8.0 8.0
Height(ft):6.6 6.3
Apron Length(ft):
Water Depth(ft): 0.99
Rustline Height(ft):2.4
Substrate Depth(ft):0.4 1.7
Backwatered?: Yes
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.55
Culvert Gradient: -0.82%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Constriction ratio gray
  2. Culvert is poorly aligned
  3. Compound gradient in pipe

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:GravelGravel
Subdominant:SandGravel
Stream Slope(deg.):
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 100.0 15.00
Upstream ordinary high water 135.0 15.50
Upstream ordinary high water 225.0 13.50

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Outlet Pool Water Elev 1 90.51
U/S Headwater 1 90.88
D/S Water Surface Elev (@GP) 1 0.00 80.0 89.96
D/S Grade Ctrl (Thalweg) 1 0.00 80.0 89.00
D/S Tailcrest or 1st Thalweg 1 60.00 20.0 89.97
D/S Water Surface Elev (@TWC) 1 60.00 20.0 90.51
D/S Thalweg (bottom of outlet pool) 1 70.00 10.0 89.19
D/S Thalweg 1 75.00 5.0 89.52
Outlet Invert 1 80.00 0.0 89.52
Outlet Culvert Top (top of pipe @ top of outlet miter) 1 80.00 0.0 95.75
D/S Thalweg (in thalweg @ top of outlet miter) 1 86.00 -6.0 89.36
Road Elev 1 113.50 98.67
U/S Water Surface Elev (@GP) 1 134.50 -12.5 90.84
U/S Grade Ctrl (Thalweg) (high point inside pipe) 1 134.50 -12.5 89.59
Inlet Culvert Top (in thalweg @ top of inlet miter) 1 139.00 -8.0 89.13
Inlet Culvert Invert 1 147.00 0.0 88.97
Inlet Culvert Top (top of pipe @ top of inlet miter) 1 147.00 0.0 96.09

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 (A)
Comments: Visual observation of adult coho upstream and downstream of culvert.
 
Gear Type: Visual Observation, Ground (B)
Comments: Juvenile salmonids visually observed upstream from culvert.

Fish Observations

No fish observations occurred during this survey.

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