Road Stream Crossing Site AUS_CR020

Au Sable River Watershed, East Branch Au Sable River
Lewiston Grade Rd
Grayling Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.73574 , -84.64178
T27N R03W Sec 14
Owned by State
Fish Passability 0
Total Erosion: 0.4475 tons/year
Severity: Severe
Year Inventoried: 2013
Crossing Information
Type of Crossing: Bridge
Structure Shape: Open Bottom Square/Rectangle
Inlet Type: Other
Outlet Type: At Stream Grade
Structure Material: Wood
Structure Substrate: Sand
General Conditions: Good
Structure Interior: smooth
Dimensions of Structure: Length 17.7 ft. , Width 22.1 ft. , Height 5.4 ft.
Structure Inlet
Water Depth: 1.8 ft.
Water Velocity*: 3.3 ft./sec.
Structure Outlet
Water Depth: 2.5 ft.
Water Velocity*: 3.57 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 36 ft. , Width 44 ft. , Depth 3.6 ft.
Upstream Pond: Length 65 ft. , Width 32 ft.
Riffle Information
Water Depth: 1.6 ft.
Bankfull Width: 32 ft.
Wetted Width: 28 ft.
Water Velocity: 1.67 ft./sec. (Measured with Float Test)
Dominant Substrate: Sand
Road Information
Gravel County Road
Road Condition: Fair
Road Width at Culvert: 14 ft.
Location of Low Point: Other
Runoff Path: Ditch
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Length: 0 ft.
Slope: 0%
Vegetation: Heavy
LS Factor: 0
Erosion: 0 tons/year
Right Approach
Length: 260 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.444
Erosion: 0.4452 tons/year
Erosion Information
Total Erosion at Crossing: 0.4475 tons/year
Extent of Erosion: Minor
Erosion is occurring and corrective actions can be installed to address the problem.
Location of Erosion
Erosion Dimensions
Eroded Material
Material Eroded
Total Erosion
facing downstream
Reaching Stream?
Right Approach
11.5 ft.
4 ft.
0.2 ft.
Summary Information
Fish Passability 0
A future visit to this site is recommended. To check on scour pool and upstream pond to make sure that size is increasing.
These non-native species were observerd at this site: Spotted Knapweed, Quenn Anne's Lace