Fish Passage Site 20501508

Coordinates (dec. deg.): 62.35531°, -150.66957°
Legal Description: S026N008W12
Region: South Central
Road Name: Petersville Road

Datum: WGS84
Quad Name / ITM: Talkeetna B-2
AWC Stream #:
Stream Name: Twentymile Creek 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 PRK09-PVR31

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

Overall Fish Passage Rating: Gray

Tidal: No
Backwatered: No

Step Pools:
Construction Year:


Site Observations:

  1. Culvert gradient gray
  2. Outfall height gray
  3. Mechanical damage or joints parting

Comments: Outlet badly bent. Water trickles thru holes in bottom of pipe 0.5' u/s outlet. Probably a barrier at present flow

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Gray
 
Length(ft): 40.6
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.67
Condition Rating(1-5): 2
Approach Angle: 27.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):3.0 2.9
Height(ft):3.0 2.6
Apron Length(ft):
Water Depth(ft): 0.0
Rustline Height(ft):1.7
Substrate Depth(ft):0.0 0.0
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.17
Outfall Type: Cascade Over Rip-Rap
Constriction Ratio: 0.79
Culvert Gradient: 0.64%
Max Slope:
Max Slope Length:
 

Comments: Outfall is a shallow cascade over cobble.
  Culvert Observations:
  1. Culvert gradient gray
  2. Outfall height gray
  3. Mechanical damage or joints parting

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:CobbleCobble
Subdominant:BoulderGravel
Stream Slope(deg.):
Stream Flow Stage:Low, Discontinuous Channel
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 17.0 3.50
Upstream ordinary high water 35.0 3.50
Upstream ordinary high water 65.0 4.00

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Outlet Pool Water Elev 1 96.53
U/S Headwater 1 97.20
D/S Grade Ctrl (Thalweg) 1 0.00 14.0 96.45
D/S Water Surface Elev (WS @ GP) 1 0.00 14.0 96.49
D/S Tailcrest or 1st Thalweg 1 8.00 6.0 96.47
D/S Water Surface Elev (WS @ TWC) 1 8.00 6.0 96.53
D/S Thalweg (bottom of out pool) 1 11.00 3.0 96.30
Outlet Invert 1 14.00 0.0 96.70
Road Elev 1 34.00 101.65
Inlet Culvert Invert (Pool imm. u/s inlet) 1 54.00 0.0 96.96

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