Fish Passage Site 20103955

Coordinates (dec. deg.): 62.27876°, -145.43544°
Legal Description: C006N001W28
Region: South Central
Road Name: Pipeline Acess Road

Datum:
Quad Name / ITM: Gulkana B-3
AWC Stream #:
Stream Name: Bear Creek

Elevation:

Site Comments: None

Survey Date: Sep 10, 2020

Survey UPD21-TAP3

Project Supervisor: Kim Clark, ADFG — Anchorage, AK
Observers: Kirsti Jurica, Nicole Farnham

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Culvert gradient gray
  2. Constriction ratio gray
  3. Mechanical damage or joints parting

Comments: Inlet invert joints are parting. Isolated pools upstream and downstream, Abundant juvenile grayling in pools. Although approach angle is aligned, stream channel makes a 90 degree turn 50 ft upstream. Overflow pipe is aligned with valley. Rip Rap at outlet. Submitted by Kirsti Jurica with CRWP.

Culvert Measurements

ID: 1 Structure Type: Pipe-arch (Structural aluminum plate) Fish Passage Rating: Gray
 
Length(ft): 89.5
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.75
Corrugation Width(in.): 9.33
Condition Rating(1-5): 3
Approach Angle: 10.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: Boulder
InletOutlet
Width(ft):7.45 7.95
Height(ft):6.01 6.53
Apron Length(ft):
Water Depth(ft): 0.73
Rustline Height(ft):2.6
Substrate Depth(ft):
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height:
Outfall Type: At Stream Grade
Constriction Ratio: 0.703
Culvert Gradient: 1.50%
Max Slope:
Max Slope Length:
 

Comments: Substrate depth at inlet and outlet not measured or recorded. Outlet substrate noted as armored rock. Althought approach angle is aligned stream channel makes a 90 degree turn 50' upstream. Overflow pipe is aligned with valley.

  Culvert Observations:
  1. Culvert gradient gray
  2. Constriction ratio gray
  3. Mechanical damage or joints parting
ID: 2 Structure Type: Pipe-arch (Structural aluminum plate) Fish Passage Rating: Gray
 
Length(ft): 96.76
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.75
Corrugation Width(in.): 9.33
Condition Rating(1-5): 3
Approach Angle: 10.0
Sedimentation At Inlet:
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):8.95 9.5
Height(ft):6.75 6.95
Apron Length(ft):
Water Depth(ft):
Rustline Height(ft):
Substrate Depth(ft):
Backwatered?:
Baffles Present: Yes
Embedded?: No
Outfall Height:
Outfall Type:
Constriction Ratio: 0.703
Culvert Gradient: 2.80%
Max Slope:
Max Slope Length:
 

Comments: Inlet and outlet noted to have very small miter. Outlet has armor rock noted as substrate. A baffle is noted in the longitudinal profile for the overflow pipe. Overflow pipe is aligned with the valley.

  Culvert Observations:
  1. Constriction ratio gray
  2. Culvert gradient gray
  3. Mechanical damage or joints parting

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:GravelCobble
Subdominant:CobbleBoulder
Stream Slope(deg.):2.5
Stream Flow Stage:Low
Stream Width Type Distance From
Crossing (ft)
Stream
Width (ft)
Upstream ordinary high water 11.70
Upstream ordinary high water 8.90
Upstream ordinary high water 11.40

Elevations

Locator ID Culvert
Number
River
Distance (ft)1
Distance From
Crossing (ft)2
Relative
Elevation (ft)
Road Elev (Road surface) 100.36
Outlet Invert (Overflow pipe, no distance included) 84.68
Outlet Culvert Top 91.63
Road Elev (Road Surface) 100.08
Inlet Culvert Top 94.13
Inlet Culvert Invert 87.38
Misc. (Baffle) 88.68
Misc. (Berm 16 feet upstream of overflow inlet) 89.67
U/S Thalweg (Dry 20' upstream of overflow pipe) 0.00 88.11
U/S Thalweg 142.00 84.77
U/S Water Surface Elev 142.00 85.37
Inlet Culvert Invert (Dry) 167.00 84.04
Inlet Culvert Top 167.00 90.05
Outlet Culvert Top 256.00 89.27
Outlet Invert 256.00 82.74
Max Pool Depth 264.00 82.76
D/S Water Surface Elev 264.00 82.52
D/S Thalweg 286.00 83.12
D/S Water Surface Elev 286.00 83.51
D/S Thalweg 360.00 83.40
D/S Water Surface Elev 360.00 83.64
D/S Thalweg 371.00 80.06
D/S Water Surface Elev 371.00 83.31

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