Road Stream Crossing Site AUS_CR068

Au Sable River Watershed, South Branch Au Sable River
Chase Bridge Rd
South Branch Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.5408 , -84.55053
T25N R02W Sec 22
Owned by Private
Fish Passability 0
Structure is NOT Perched
Total Erosion: 6.1103 tons/year
Severity: Severe
Year Inventoried: 2013
Crossing Information
Type of Crossing: Bridge
Structure Shape: Open Bottom Square/Rectangle
Inlet Type: Wingwall 10-30 Degree
Outlet Type: At Stream Grade
Structure Material: Concrete
Structure Substrate: Rock
General Conditions: Fair
Structure Interior: smooth
Dimensions of Structure: Length 30.5 ft. , Width 59 ft. , Height 6.7 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 3 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 3.57 ft./sec.
Structure Outlet
Water Depth: 2.5 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 0.41 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 40 ft. , Width 46 ft. , Depth 4.5 ft.
Upstream Pond: Length 0 ft. , Width 0 ft. , Depth 0 ft.
Riffle Information
Water Depth: 3.2 ft.
Bankfull Width: 67 ft.
Wetted Width: 58.5 ft.
Water Velocity: 2.5 ft./sec. (Measured with Float Test)
Dominant Substrate: Gravel
Road Information
Paved County Road
Road Condition: Poor
Road Width at Culvert: 30 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Left Approach
Length: 690 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.534
Erosion: 0.3651 tons/year
Right Approach
Length: 1000 ft.
Slope: More Than 10%
Vegetation: Heavy
LS Factor: 5.785
Erosion: 5.7372 tons/year
Erosion Information
Total Erosion at Crossing: 6.1103 tons/year
Extent of Erosion: Minor
Location of Erosion
Erosion Dimensions
Eroded Material
Material Eroded
Total Erosion
facing downstream
Reaching Stream?
Left Downstream
4 ft.
10 ft.
2 ft.
Summary Information
Fish Passability 0
A future visit to this site is recommended. To check scour pool