Road Stream Crossing Site AUS_CR055

Au Sable River Watershed, Tributary of Au Sable River
Polly Trail
Grayling Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.6633 , -84.50344
T26N R02W Sec 12
Owned by Private
Fish Passability 0
Structure is NOT Perched
Total Erosion: 8.5536 tons/year
Severity: Severe
Year Inventoried: 2013
Crossing Information
Type of Crossing: culvert(s)
Number of Structures: 1
Structure Shape: Round
Inlet Type: Projecting
Outlet Type: At Stream Grade
Structure Material: Metal
Structure Substrate: None
General Conditions: Good
Structure Interior: corrugated
Dimensions of Structure: Length 33 ft. , Width 1.7 ft. , Height 1.6 ft.
Percentage Crushed: Inlet: 1% to 25% Outlet: 0% In Pipe: 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 0.8 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 4 ft./sec.
Structure Outlet
Water Depth: 0.9 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 0.85 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 10 ft. , Width 8 ft. , Depth 1.1 ft.
Upstream Pond: Length 0 ft. , Width 0 ft. , Depth 0 ft.
Riffle Information
Water Depth: 0.5 ft.
Bankfull Width: 11 ft.
Wetted Width: 4 ft.
Water Velocity: 0.93 ft./sec. (Measured with Float Test)
Dominant Substrate: Gravel
Road Information
Gravel County Road
Road Condition: Good
Road Width at Culvert: 15.5 ft.
Location of Low Point: At Stream
Runoff Path: Roadway
Fill Depth: 4 ft.
Slope: 1:1.5
Fill Depth: 4 ft.
Slope: Vertical
Left Approach
Length: 263 ft.
Slope: More Than 10%
Vegetation: Partial
LS Factor: 4.187
Erosion: 4.702 tons/year
Right Approach
Length: 430 ft.
Slope: 6% to 10%
Vegetation: Partial
LS Factor: 2.096
Erosion: 3.8484 tons/year
Erosion Information
Total Erosion at Crossing: 8.5536 tons/year
Extent of Erosion: Minor
Location of Erosion
Erosion Dimensions
Eroded Material
Material Eroded
Total Erosion
facing downstream
Reaching Stream?
Left Upstream
9.5 ft.
15 ft.
0.2 ft.
Left Downstream
6 ft.
4.5 ft.
0.2 ft.
Summary Information
Fish Passability 0
Fish Passage is an area of concern for this site. Inlet water velocity is extremely fast, and debris may be blocking passage.
A future visit to this site is recommended. To assess water velocity/debris blocking passage.