Fish Passage Site 20401283

Coordinates (dec. deg.): 61.52637°, -149.51404°
Legal Description: S017N001W31
Region: South Central
Road Name: Driveway off Trapline Drive

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #: 247-50-10300-2012
Stream Name: Cottonwood Slough

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-MS024

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

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Woody Debris
  2. Inlet perch

Comments: Landowner stated that adult salmon used to pass through, but not anymore. They stated that fish cannot pass through the culverts and die at times throughout the season, rather then just at spawning times. Inlet is severely crushed from right side and is jammed with debris.The entire culvert is rusted and cannot see through the culvert. There is a rusted hole at the bottom of the culvert on the inlet side.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Red
 
Length(ft): 40.5
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 1
Approach Angle: 0.0
Sedimentation At Inlet: No
Inlet Substrate: Gravel
Outlet Substrate: Sand
InletOutlet
Width(ft):1.0 2.5
Height(ft):2.3 1.8
Apron Length(ft):
Water Depth(ft):0.0 1.08
Rustline Height(ft):1.0
Substrate Depth(ft):0.0 0.55
Backwatered?: No
Baffles Present: No
Embedded?: No
Embedded Depth(ft): 0.0
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.23
Culvert Gradient: 0.86%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Woody Debris
  2. Inlet perch

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:Silt/ClaySilt/Clay
Subdominant:OrganicOrganic
Stream Slope(deg.):0.3
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 44.0 8.90
Upstream ordinary high water 89.0 11.40
Upstream ordinary high water 131.0 10.90
Upstream ordinary high water 155.0 10.80

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 99.43
U/S Thalweg 0.00 93.65
U/S Water Surface Elev 0.00 94.32
Inlet Culvert Top 16.85 95.26
U/S Water Surface Elev 18.00 94.30
Inlet Culvert Invert 18.00 93.07
Outlet Invert 58.50 93.14
Outlet Culvert Top 58.50 94.92
D/S Water Surface Elev 58.50 94.22
D/S Thalweg 221.50 92.62
D/S Water Surface Elev 221.50 93.66

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

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