Road Stream Crossing Site AUS_CR038

Au Sable River Watershed, East Branch Au Sable River
North Down River Rd
Grayling Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.67089 , -84.7054
T26N R03W Sec 8
Owned by Local Government
Fish Passability 0.9
Total Erosion: 0.3543 tons/year
Severity: Moderate
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: Concrete
Structure Substrate: Rock
General Conditions: Fair
Structure Interior: smooth
Dimensions of Structure: Length 56 ft. , Width 45.2 ft. , Height 10.7 ft.
Structure Inlet
Water Depth: 3.3 ft.
Water Velocity*: 1.05 ft./sec.
Structure Outlet
Water Depth: 3 ft.
Water Velocity*: 1.11 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Additional Comments
City to south of crossing, private to northwest of crossing, and Grayling Twp. To northeast of crossing.
Stream Information
Stream Flow: Less than Bankfull
Upstream Pond: Length 125 ft. , Width 50 ft.
Riffle Information
Water Depth: 2.2 ft.
Bankfull Width: 52 ft.
Wetted Width: 45.5 ft.
Water Velocity: 1.6 ft./sec. (Measured with Float Test)
Dominant Substrate: Sand
Road Information
Paved County Road
Road Condition: Good
Road Width at Culvert: 30.7 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: 660 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.529
Erosion: 0.3543 tons/year
Erosion Information
Total Erosion at Crossing: 0.3543 tons/year
Extent of Erosion: Minor
Notes: Slightly undercut banks at upstream left approach due to Grayling township park access and lack of riparian vegetation.
Summary Information
Fish Passability 0.9
A future visit to this site is recommended. Upstream pond is considerably large, deep, and silty but could be mostly due to the presence of the fish hatchery immedietly downstream from the crossing.
These non-native species were observerd at this site: Honeysuckle, Spotted Knotweed, Leafy Spurge