Fish Passage Site 20103476

Coordinates (dec. deg.): 61.59437°, -145.22308°
Legal Description: C003S001E21
Region: South Central
Road Name: 14 APL 4

Datum: NAD83
Quad Name / ITM: Valdez C-4
AWC Stream #: 212-20-10080-2331-3081
Stream Name: Little Tonsina River

Elevation:

Site Comments: Road at MP 74.2 on the Richardson Highway, Pipeline access road.

Survey Date: Sep 25, 2015

Survey UPDATE-ALY1

Project Supervisor: Gillian O'Doherty, ADFG
Observers: Kirsti Jurica

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools: No
Construction Year:


Site Observations:

  1. Constriction ratio red
  2. Culvert gradient red
  3. Outfall height red
  4. Inlet perch
  5. Culvert is too short
  6. Road Fill (pushed off road by grader)

Comments: Old blown out culverts downstream. Very productive Chinook and Coho salmon stream.

Culvert Measurements

ID: 1 Structure Type: Pipe-arch (Structural steel plate) Fish Passage Rating: Red
 
Length(ft): 46.8
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.0
Corrugation Width(in.): 6.0
Condition Rating(1-5): 2
Approach Angle: 20.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):11.1 11.31
Height(ft):7.26 7.12
Apron Length(ft):
Water Depth(ft): 1.4
Rustline Height(ft):4.1
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.36
Outfall Type: Hydraulic Jump
Constriction Ratio: 0.37
Culvert Gradient: 0.70%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Outfall height red
  2. Constriction ratio red
  3. Inlet perch
  4. Culvert is too short
  5. Road bank erosion
  6. Cut-slope slumping or sliding into culvert (single event)
ID: 2 Structure Type: Pipe-arch (Structural steel plate) Fish Passage Rating: Red
 
Length(ft): 39.1
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 2.0
Corrugation Width(in.): 6.0
Condition Rating(1-5): 2
Approach Angle: 20.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):11.37 10.75
Height(ft):7.4 7.58
Apron Length(ft):
Water Depth(ft): 0.77
Rustline Height(ft):3.0
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.23
Outfall Type: Hydraulic Jump
Constriction Ratio: 0.37
Culvert Gradient: 2.70%
Max Slope:
Max Slope Length:
 

Comments: Outlet damage.

  Culvert Observations:
  1. Culvert gradient red
  2. Outfall height gray
  3. Constriction ratio red
  4. Inlet perch
  5. Culvert is too short
  6. Road Fill (pushed off road by grader)

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:CobbleCobble
Subdominant:GravelGravel
Stream Slope(deg.):0.1
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)
Stream
Width (ft)
Downstream ordinary high water 47.60
Downstream ordinary high water 35.80
Downstream ordinary high water 47.50
Upstream ordinary high water 47.50
Upstream ordinary high water 34.00
Upstream ordinary high water 42.50
Upstream ordinary high water 45.60

Elevations

Locator ID Culvert
Number
River
Distance (ft)1
Distance From
Crossing (ft)2
Relative
Elevation (ft)
Road Elev (Road is at a slant, upper point) 105.50
Road Elev (Lower road point) 104.62
D/S Grade Ctrl (Thalweg) 0.00 90.49
D/S Water Surface Elev 0.00 92.13
D/S Grade Ctrl (Thalweg) 100.00 91.70
D/S Water Surface Elev 100.00 92.71
D/S Thalweg 147.00 91.14
D/S Water Surface Elev 147.00 93.44
D/S Thalweg (Riffle) 2 172.00 91.29
D/S Water Surface Elev 2 172.00 93.44
Outlet Culvert Top 1 180.00 99.52
Outlet Invert 1 180.00 92.40
D/S Water Surface Elev 1 180.00 93.80
Outlet Invert 2 187.00 92.90
D/S Water Surface Elev 2 187.00 93.67
Outlet Culvert Top 2 187.00 100.48
Inlet Culvert Invert 1 227.00 92.74
U/S Water Surface Elev 1 227.00 95.58
Inlet Culvert Invert 2 227.00 93.98
U/S Water Surface Elev 2 227.00 94.85
Inlet Culvert Top 1 227.00 100.00
Inlet Culvert Top 2 227.00 101.38
U/S Grade Ctrl (Thalweg) 239.00 92.59
U/S Water Surface Elev 239.00 95.83
U/S Grade Ctrl (Thalweg) 377.00 94.01
U/S Water Surface Elev 377.00 95.86
U/S Grade Ctrl (Thalweg) 547.00 95.35
U/S Water Surface Elev 547.00 96.00

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