Fish Passage Site 20401230

Coordinates (dec. deg.): 61.52448°, -149.52934°
Legal Description: S017N001W31
Region: South Central
Road Name: Surrey Road

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

Elevation:

Site Comments: None

Survey Date: Aug 11, 2009

Survey MSB09-SUR02

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

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: No

Step Pools: No
Construction Year: 2007


Site Observations:

  1. Shallow fill; inadequate roadfill volume above culvert

Comments: Post-replacement survey of MSB04ML134; Upstream grade = 0.53%.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 50.7
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 3.0
Condition Rating(1-5): 5
Approach Angle: 9.0
Sedimentation At Inlet: No
Inlet Substrate: Gravel
Outlet Substrate: Gravel
InletOutlet
Width(ft):5.1 5.1
Height(ft):3.3 2.9
Apron Length(ft):
Water Depth(ft): 0.53
Rustline Height(ft):
Substrate Depth(ft):1.8 2.2
Backwatered?: No
Baffles Present: No
Embedded?: Yes
Embedded Depth(ft): 1.8
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.96
Culvert Gradient: 0.26%
Max Slope:
Max Slope Length:
 

Comments: U/S stream gradient = 0.53%. Flat inside pipe. pipe slope calc'd based on inverts.
  Culvert Observations:
  1. Shallow fill; inadequate roadfill volume above culvert

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:Silt/ClaySilt/Clay
Subdominant:GravelGravel
Stream Slope(deg.):0.53
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 40.0 4.50
Upstream ordinary high water 100.0 5.50
Upstream ordinary high water 165.0 6.00

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Road Elev 1 97.57
D/S Water Surface Elev (d/s ws) 1 0.00 50.0 93.01
D/S Water Surface Elev 1 36.00 14.0 93.08
D/S Thalweg (no clear TWC) 1 36.00 14.0 92.43
Outlet Invert (on substrate) 1 50.00 0.0 92.57
Outlet Pool Water Elev 1 50.00 93.10
U/S Headwater 1 100.70 93.15
Inlet Culvert Invert (on substrate) 1 100.70 0.0 92.70
U/S Grade Ctrl (Thalweg) 1 106.70 6.0 92.79
U/S Water Surface Elev (ws @ gp, stream gradient) 1 106.70 6.0 93.36
U/S Thalweg 1 120.70 20.0 92.54
U/S Grade Ctrl (Thalweg) 1 224.70 124.0 93.65
U/S Water Surface Elev (Stream gradient) 1 224.70 124.0 93.98

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