Fish Passage Site 20404050

Coordinates (dec. deg.): 61.54545°, -149.45059°
Legal Description: S017N001W21
Region: South Central
Road Name: S. Fern Street

Datum: WGS84
Quad Name / ITM: Anchorage C-7
AWC Stream #:
Stream Name: Cottonwood Slough

Elevation:

Site Comments: None

Survey Date: Sep 08, 2023

Survey MSB23-MS019

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

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Other, including vibrations, cavitation, etc.

Comments: Small fish spotted upstream, species unknown.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Gray
 
Length(ft): 45.62
Inlet Type: Flared Inlet
Outlet Type: Flared Inlet
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.75
Condition Rating(1-5): 4
Approach Angle: 0.0
Sedimentation At Inlet: Yes
Inlet Substrate: Organic
Outlet Substrate: Organic
InletOutlet
Width(ft):1.98 1.98
Height(ft):1.95 1.93
Apron Length(ft):3.02 3.03
Water Depth(ft): 0.91
Rustline Height(ft):0.92
Substrate Depth(ft):0.0 0.32
Backwatered?: No
Baffles Present: No
Embedded?: No
Embedded Depth(ft): 0.0
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio:
Culvert Gradient: 0.70%
Max Slope:
Max Slope Length:
 

Comments: Inlet apron acting as water control.Apron elevated, gradient is -7.62%. Inlet invert apron bottom is 0.72ft.
  Culvert Observations:
  1. Other, including vibrations, cavitation, etc.

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:OrganicOrganic
Subdominant:SandSand
Stream Slope(deg.):0.75
Stream Flow Stage:Medium

No stream width data available.

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 103.69
D/S Water Surface Elev 0.00 99.03
D/S Thalweg (Bottom of apron) 27.00 98.77
Outlet Invert 30.00 98.61
D/S Water Surface Elev 30.00 99.52
Outlet Culvert Top 30.00 100.62
Inlet Culvert Invert 75.62 99.44
U/S Water Surface Elev 75.62 99.84
Inlet Culvert Top 75.62 97.59
U/S Thalweg (Top of apron) 76.00 99.40
U/S Thalweg (Bottom of apron) 78.62 99.63
U/S Water Surface Elev (Watersurface at bottom of apron) 78.62 99.67
U/S Water Surface Elev 105.62 99.59
U/S Thalweg 105.62 98.91

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