Fish Passage Site 20501042

Coordinates (dec. deg.): 61.66444°, -149.38194°
Legal Description: S018N001W12
Region: South Central
Road Name: Coles Road

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #:
Stream Name: Little Susitna River 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 MSB09-COL01

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

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools:
Construction Year: 2008


Site Observations:

  1. Shallow fill; inadequate roadfill volume above culvert
  2. Culvert is poorly aligned

Comments: Post-replacement survey of MSB04ML016; Upstream gradient = 2.5%.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 70.2
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 4
Approach Angle: 54.0
Sedimentation At Inlet: No
Inlet Substrate: Gravel
Outlet Substrate: Gravel
InletOutlet
Width(ft):6.9 7.4
Height(ft):5.4 4.3
Apron Length(ft):
Water Depth(ft): 0.35
Rustline Height(ft):
Substrate Depth(ft):1.8 2.4
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Embedded Depth(ft): 1.8
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 1.33
Culvert Gradient:
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Shallow fill; inadequate roadfill volume above culvert
  2. Culvert is poorly aligned

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:Silt/ClayGravel
Subdominant:GravelSand
Stream Slope(deg.):2.5
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 45.0 5.00
Upstream ordinary high water 72.0 4.50
Upstream ordinary high water 102.0 6.00

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 1 100.28
D/S Grade Ctrl (Thalweg) 1 0.00 60.0 91.65
D/S Water Surface Elev 1 0.00 60.0 92.07
D/S Tailcrest or 1st Thalweg (1st GP d/s; no outlet pool) 1 45.00 15.0 92.55
D/S Water Surface Elev 1 45.00 15.0 92.79
D/S Thalweg 1 55.00 5.0 92.53
Outlet Invert 1 60.00 0.0 92.87
Outlet Pool Water Elev 1 60.00 93.22
Inlet Culvert Invert (thalweg on substrate (R side of pipe)) 1 130.20 0.0 94.27
U/S Headwater 1 130.20 94.90
U/S Water Surface Elev (ws @ gp) 1 140.20 10.0 95.17
U/S Grade Ctrl (Thalweg) (1st TC u/s) 1 140.20 10.0 94.75
U/S Grade Ctrl (Thalweg) 1 170.20 40.0 95.32
U/S Water Surface Elev (ws @ gp) 1 170.20 40.0 95.70
U/S Grade Ctrl (Thalweg) 1 215.20 85.0 96.10
U/S Water Surface Elev (ws @ gp) 1 215.20 85.0 96.45
U/S Grade Ctrl (Thalweg) 1 263.20 133.0 97.82
U/S Water Surface Elev (ws @ gp) 1 263.20 133.0 98.13

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