Fish Passage Site 20401292

Coordinates (dec. deg.): 61.53047°, -149.52480°
Legal Description: S017N001W30
Region: South Central
Road Name: Redoubt

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

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 MSB23-MS028

Project Supervisor: Michael Mazzacavallo, Alaska Department of Fish and Game — Anchorage, AK
Observers: Michael Mazzacavallo, Kat Leavitt, Beth Evers

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year: 2013


Site Observations:

  1. Culvert sagging in middle

Comments: Juvenile fish spotted U/S. Pipe visually sagging severely under road.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 52.66
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 3.0
Condition Rating(1-5): 4
Approach Angle: 0.0
Sedimentation At Inlet: No
Inlet Substrate: Sand
Outlet Substrate: Organic
InletOutlet
Width(ft):5.02 5.49
Height(ft):2.42 2.61
Apron Length(ft):
Water Depth(ft):0.0 0.79
Rustline Height(ft):0.6
Substrate Depth(ft):2.37 2.2
Backwatered?: Yes
Baffles Present: No
Embedded?: Yes
Embedded Depth(ft): 2.2
Outfall Height:
Outfall Type: At Stream Grade
Constriction Ratio: 0.61
Culvert Gradient: 0.06%
Max Slope:
Max Slope Length:
 

Comments: Culvert gradient calculated using WS due to warp in pipe.
  Culvert Observations:
  1. Culvert sagging in middle

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:OrganicOrganic
Subdominant:SandSand
Stream Slope(deg.):0.28
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 29.0 6.75
Upstream ordinary high water 43.0 9.40
Upstream ordinary high water 54.0 7.40
Upstream ordinary high water 88.0 9.60

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 100.33
D/S Thalweg 0.00 95.70
D/S Water Surface Elev 0.00 96.23
D/S Water Surface Elev 43.00 96.31
D/S Thalweg 43.00 95.24
Outlet Culvert Top 100.00 98.81
D/S Water Surface Elev 100.00 96.58
Outlet Invert 100.00 95.79
Inlet Culvert Invert 152.66 95.76
U/S Water Surface Elev 152.66 96.61
Inlet Culvert Top 152.66 98.54
U/S Water Surface Elev 204.66 96.87
U/S Thalweg 204.66 95.98
U/S Thalweg 251.66 96.11
U/S Water Surface Elev 251.66 96.94

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.

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