Fish Passage Improvement site 20401269

Fish Passage Site 20401269

Coordinates (dec. deg.): 61.63196°, -149.26443°
Legal Description: S018N001E22
Region: South Central
Road Name: Twin Lakes Drive

Datum: NAD83
Quad Name / ITM: Anchorage C-7
AWC Stream #:
Stream Name: Neklason Lake Tributary

Elevation:

Site Comments: East Twin Lakes Drive

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-CT112

site photos

Observers: Edward Weiss, Doug Hill, Joe Conner

Overall Fish Passage Rating: Red

Tidal: No
Backwatered: No

Step Pools:
Construction Year:

Site Observations:

Improper bedding
Culvert gradient red
Structural Problem

Comments: Bowed in corner; Outlet perched above stream; Appears that water over road @ times or run-off from road eroding outlet side of road.

Culvert Measurements

ID: 1

Structure Type: Circular pipe (Corrugated Metal)

Fish Passage Rating: Red

Length(ft): 32.0

Inlet Type: Projecting

Outlet Type:

Corrugation Depth(in.): 0.5

Corrugation Width(in.): 2.67

Condition Rating(1-5): 1

Approach Angle:

Sedimentation At Inlet:

Inlet Substrate: Sand

Outlet Substrate: Gravel

	Inlet	Outlet
Width(ft):	2.0	2.0
Height(ft):	2.0	2.0
Apron Length(ft):
Water Depth(ft):	0.5	0.1
Rustline Height(ft):
Substrate Depth(ft):	0.0	0.0

Backwatered?:

Baffles Present: No

Embedded?: No

Outfall Height:

Outfall Type:

Constriction Ratio:

Culvert Gradient: 6.53%

Max Slope:

Max Slope Length:

Culvert Observations:

Structural Problem
Improper bedding

Stream Measurements

Stream Substrates	Upstream	Downstream
Dominant:	Sand	Gravel
Subdominant:

Stream Slope(deg.):
Stream Flow Stage:	Medium

Stream Width Type	Distance From Crossing (ft)	Stream Width (ft)
Downstream ordinary high water	56.0	8.10
Downstream ordinary high water	103.0	6.00
Upstream ordinary high water	50.0	2.50
Upstream ordinary high water	100.0	6.00

Elevations

Locator ID	Culvert Number	River Distance (ft)¹	Distance From Crossing (ft)²	Relative Elevation (ft)
Outlet Culvert Top	1			93.38
Inlet Culvert Top	1			95.20
U/S Thalweg				97.10
U/S Thalweg				99.49
D/S Thalweg		0.00	103.0	77.94
D/S Thalweg		46.50	56.5	80.42
Outlet Thalweg	1	103.00	0.0	90.21
Outlet Invert	1	103.00	0.0	91.07
Road Elev		119.00		95.23
Road Elev		119.00		95.66
Inlet Thalweg	1	135.00	0.0	93.12
Inlet Culvert Invert	1	135.00	0.0	93.16
U/S Thalweg	1	154.00	19.0	93.73

Notes:

River distance is measured continuously throughout the survey reach along the thalweg of the stream.
Measured from each end of the crossing along the thalweg of the stream.

Fish Sampling Efforts

Gear Type: Minnow Trap (B)

Trap Duration(h): 1

Fish Observations

Species: juvenile/adult Dolly Varden		Life History: Unknown
Total Fish Observed: 6	Fish Measured: 3	Fork Lengths (mm) Min: 90 Max: 90 Mean: 90
Collected/Observed by Gear Type: Downstream Minnow Trap (6)

Photos

Questions or comments about this report can be directed to dfg.dsf.webmaster@alaska.gov