Road Stream Crossing Site AUS_CR010

Au Sable River Watershed, Au Sable River
Old Dam Rd
Grayling Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.66368 , -84.74035
T26N R04W Sec 12
Owned by Private
Fish Passability 0
Structure is NOT Perched
Total Erosion: 0.1503 tons/year
Severity: Severe
Year Inventoried: 2013
Crossing Information
Type of Crossing: Bridge
Structure Shape: Open Bottom Square/Rectangle
Inlet Type: 10-30 Degree or 30-70 Degree
Outlet Type: At Stream Grade
Structure Material: Wood
Structure Substrate: Gravel
General Conditions: Fair
Structure Interior: smooth
Dimensions of Structure: Length 34 ft. , Width 26 ft. , Height 7.8 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 1.8 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.94 ft./sec.
Structure Outlet
Water Depth: 2.4 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 3.85 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 75 ft. , Width 67 ft. , Depth 2.3 ft.
Riffle Information
Water Depth: 1.8 ft.
Bankfull Width: 54 ft.
Wetted Width: 50.5 ft.
Water Velocity: 2.3 ft./sec. (Measured with Float Test)
Dominant Substrate: Sand
Road Information
Paved County Road
Road Condition: Good
Road Width at Culvert: 30 ft.
Location of Low Point: Other
Runoff Path: Roadway
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Left Approach
Length: 320 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.464
Erosion: 0.1473 tons/year
Length: 0 ft.
Slope: 0%
Vegetation: Heavy
LS Factor: 0
Erosion: 0 tons/year
Erosion Information
Total Erosion at Crossing: 0.1503 tons/year
Extent of Erosion: Minor
Notes: Foot path access erosion at upstream and downstream right embankments.
Location of Erosion
Erosion Dimensions
Eroded Material
Material Eroded
Total Erosion
facing downstream
Reaching Stream?
Right Approach
15 ft.
4 ft.
0.2 ft.
Summary Information
Fish Passability 0
A future visit to this site is recommended. Guard rail supports are rotting