Fish Passage Site 20401358

Coordinates (dec. deg.): 61.55190°, -149.29947°
Legal Description: S017N001E20
Region: South Central
Road Name: Nelson Road

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #: 247-50-10260-2019
Stream Name: Wasilla Creek

Elevation:

Site Comments: Culvert removed in February 2012. Abandoned road off Nelson Rd.

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 MSCS1-WA068

Observers: Edward Weiss, Joe Conner, Olof Jacobsson

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools:
Construction Year:


Site Observations:

  1. Constriction ratio red

Comments: Inlet erosion; no use of culvert after bridge installed dwnstream and should eventually be removed.

Culvert Measurements

ID: 1 Structure Type: Open-bottom arch (Strutural Metal Plate) Fish Passage Rating: Red
 
Length(ft): 22.0
Inlet Type: Projecting
Outlet Type:
Corrugation Depth(in.): 1.0
Corrugation Width(in.): 5.0
Condition Rating(1-5): 1
Approach Angle:
Sedimentation At Inlet: Yes
Inlet Substrate: Gravel
Outlet Substrate: Gravel
InletOutlet
Width(ft):10.0 10.0
Height(ft):4.0 3.2
Apron Length(ft):
Water Depth(ft):4.0 1.7
Rustline Height(ft):
Substrate Depth(ft):0.0 0.8
Backwatered?: No
Baffles Present: No
Embedded?: No
Outfall Height: 0.0
Outfall Type: At Stream Grade
Constriction Ratio: 0.38
Culvert Gradient: -3.70%
Max Slope:
Max Slope Length:
  Culvert Observations:
  1. Hydraulic flows exceeded capacity
  2. Cut-slope slumping or sliding into culvert (single event)
  3. Constriction ratio red

Stream Measurements

Stream SubstratesUpstreamDownstream
Dominant:GravelGravel
Subdominant:
Stream Slope(deg.):
Stream Flow Stage:
Stream Width Type Distance From
Crossing (ft)		 Stream
Width (ft)
Upstream ordinary high water 16.0 25.00
Upstream ordinary high water 65.0 26.00
Upstream ordinary high water 123.0 27.00

Elevations

Locator ID Culvert
Number		 River
Distance (ft)1		 Distance From
Crossing (ft)2		 Relative
Elevation (ft)
Inlet Culvert Top 1 91.02
Outlet Culvert Top 1 91.84
D/S Thalweg 0.00 95.0 88.20
D/S Thalweg 68.00 27.0 89.21
D/S Tailcrest or 1st Thalweg 90.00 5.0 90.00
Outlet Thalweg 1 95.00 0.0 88.46
Outlet Invert 1 95.00 0.0 88.62
Road Elev 106.00 95.18
Road Elev 106.00 95.26
Inlet Culvert Invert 1 117.00 0.0 86.32
Inlet Thalweg 1 117.00 0.0 86.32
U/S Thalweg 1 118.00 1.0 87.57
U/S Thalweg 182.00 65.0 89.95
U/S Thalweg 240.00 123.0 89.70

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.

Photos

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