Fish Passage Improvement site 20501203

Fish Passage Site 20501203

Coordinates (dec. deg.): 61.48902°, -149.67320°
Legal Description: S016N002W08
Region: South Central
Road Name: O'Grady Drive

Datum: WGS84
Quad Name / ITM: Anchorage B-8
AWC Stream #:
Stream Name: O'Brien Creek

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 MSB09-OGD01

site photos

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

Overall Fish Passage Rating: Green

Tidal: No
Backwatered: Yes

Step Pools:
Construction Year:

Site Observations:

Shallow fill; inadequate roadfill volume above culvert
Hydraulic flows exceeded capacity

Comments: None

Culvert Measurements

ID: 1

Structure Type: Circular pipe (Corrugated steel)

Fish Passage Rating: Green

Length(ft): 47.9

Inlet Type: Projecting

Outlet Type: Projecting

Corrugation Depth(in.): 0.5

Corrugation Width(in.): 2.67

Condition Rating(1-5): 3

Approach Angle: 19.0

Sedimentation At Inlet: Yes

Inlet Substrate: Gravel

Outlet Substrate: Gravel

	Inlet	Outlet
Width(ft):	3.2	3.2
Height(ft):	1.8	1.8
Apron Length(ft):
Water Depth(ft):		0.76
Rustline Height(ft):	1.5
Substrate Depth(ft):	1.8	1.7

Backwatered?: Yes

Baffles Present: No

Embedded?: Yes

Embedded Depth(ft): 1.7

Outfall Height: 0.0

Outfall Type: At Stream Grade

Constriction Ratio: 0.74

Culvert Gradient: -0.02%

Max Slope:

Max Slope Length:

Culvert Observations:

Shallow fill; inadequate roadfill volume above culvert
Hydraulic flows exceeded capacity

Stream Measurements

Stream Substrates	Upstream	Downstream
Dominant:	Silt/Clay	Silt/Clay
Subdominant:	Cobble	Cobble

Stream Slope(deg.):	0.11
Stream Flow Stage:	Medium

Stream Width Type	Distance From Crossing (ft)	Stream Width (ft)
Upstream ordinary high water	40.0	4.50
Upstream ordinary high water	65.0	4.50
Upstream ordinary high water	107.0	4.00

Elevations

Locator ID	Culvert Number	River Distance (ft)¹	Distance From Crossing (ft)²	Relative Elevation (ft)
U/S Headwater	1			98.93
Outlet Pool Water Elev	1			98.93
D/S Grade Ctrl (Thalweg)	1	0.00	37.0	97.96
D/S Water Surface Elev (WS @ GP)	1	0.00	37.0	98.53
D/S Tailcrest or 1st Thalweg	1	24.00	13.0	98.55
D/S Water Surface Elev (WS @ TWC)	1	24.00	13.0	98.91
D/S Thalweg	1	34.50	2.5	98.45
Outlet Invert	1	37.00	0.0	98.17
Road Elev	1	61.00		100.85
Inlet Culvert Invert	1	84.90	0.0	98.16
U/S Grade Ctrl (Thalweg) (TC of 1st pool u/s)	1	85.90	1.0	98.37
D/S Water Surface Elev (WS @ GP)	1	85.90	1.0	98.93
U/S Water Surface Elev	1	124.90	40.0	98.99
U/S Grade Ctrl (Thalweg) (high pt in glide)	1	124.90	40.0	97.95
U/S Water Surface Elev (u/s WS)	1	204.90	102.0	99.04

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.