Fish Passage Site 20501509

Coordinates (dec. deg.): 62.35923°, -150.69237°
Legal Description: S026N008W11
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

Survey Date: Jul 09, 2009

Survey PRK09-PVR32

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

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: Yes

Step Pools: No
Construction Year:


Site Observations:

  1. Culvert gradient red
  2. Culvert gradient gray
  3. Hydraulic flows exceeded capacity

Comments: **Updated site photos and fish sampling information added from 9/8/16 site visit from Sampling Unmapped Streams in the MSB project.

Culvert Measurements

ID: 1 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 60.0
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.67
Condition Rating(1-5): 1
Approach Angle: 24.0
Sedimentation At Inlet: No
Inlet Substrate: Silt/Clay
Outlet Substrate: None
InletOutlet
Width(ft):4.1 4.5
Height(ft):3.0 3.5
Apron Length(ft):
Water Depth(ft): 3.07
Rustline Height(ft):1.9
Substrate Depth(ft):1.0 0.0
Backwatered?: Yes
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 1.62
Culvert Gradient: 1.90%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient red
  2. Hydraulic flows exceeded capacity
ID: 2 Structure Type: Circular pipe (Corrugated steel) Fish Passage Rating: Green
 
Length(ft): 60.5
Inlet Type: Projecting
Outlet Type: Projecting
Corrugation Depth(in.): 0.5
Corrugation Width(in.): 2.67
Condition Rating(1-5): 1
Approach Angle: 24.0
Sedimentation At Inlet: No
Inlet Substrate: None
Outlet Substrate: None
InletOutlet
Width(ft):4.3 4.8
Height(ft):3.5 3.3
Apron Length(ft):
Water Depth(ft): 3.14
Rustline Height(ft):3.3
Substrate Depth(ft):0.0 0.0
Backwatered?: Yes
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 1.62
Culvert Gradient: 0.81%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Culvert gradient gray
  2. Hydraulic flows exceeded capacity

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:Silt/ClaySilt/Clay
Subdominant:CobbleSilt/Clay
Stream Slope(deg.):
Stream Flow Stage:Medium
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 100.0 4.00
Upstream ordinary high water 160.0 4.50
Upstream ordinary high water 200.0 2.50

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
U/S Headwater (pool imm. u/s inlets) 1 99.51
U/S Headwater 2 99.51
(top of pipe at outlet) 2 99.67
(top of pipe at outlet) 1 99.94
Outlet Pool Water Elev (outlet pool for both pipes) 99.51
D/S Water Surface Elev (WS d/s) 0.00 90.0 99.51
D/S Water Surface Elev (WS @ TWC) 57.00 33.0 99.51
D/S Tailcrest or 1st Thalweg (soft stream bottom) 57.00 33.0 97.23
Outlet Invert (calculated from top of pipe) 2 90.00 0.0 96.37
Outlet Invert (calculated from top of pipe) 1 90.00 0.0 96.44
Road Elev 120.00 103.86
Inlet Culvert Invert 2 150.00 0.0 96.86
Inlet Culvert Invert (on substrate) 1 150.00 0.0 97.58

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