Road Stream Crossing Site AUS_CR119
Au Sable River Watershed, South Branch Au Sable River
Smith Bridge Public Access, M-72
South Branch Twp,
Crawford County
Information collected by:
Site Location
GPS Coordinates: 44.61495
, -84.45557
T26N
R01W
Sec 29
Owned by State
Fish Passability 0.5
Structure is NOT Perched
Total Erosion: 28.8737 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: Metal
Structure Substrate: Gravel
General Conditions: Good
Structure Interior: smooth
Dimensions of Structure: Length 15.5 ft.
, Width 86 ft.
, Height 12 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 3.4 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.99 ft./sec.
Structure Outlet
Water Depth: 3.5 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.86 ft./sec.
*Water Velocities were measured at the Surface
(with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 0 ft.
, Width 0 ft.
, Depth 0 ft.
Upstream Pond: Length 0 ft.
, Width 0 ft.
, Depth 0 ft.
Riffle Information
Water Depth: 2.4 ft.
Bankfull Width: 89 ft.
Wetted Width: 68.5 ft.
Water Velocity: 3.8 ft./sec.
(Measured with Float Test)
Dominant Substrate: Cobble
Road Information
Gravel
County Road
Road Condition: Good
Road Width at Culvert: 13 ft.
Location of Low Point: Other
Runoff Path: Ditch
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Approaches
Left Approach
Length: 930 ft.
Slope: More Than 10%
Vegetation: Partial
LS Factor: 8.666
Erosion: 28.8628 tons/year
Right Approach
Length: 0 ft.
Slope: Less Than 1%
Vegetation: Partial
LS Factor: 0.05
Erosion: 0 tons/year
Erosion Information
Total Erosion at Crossing: 28.8737 tons/year
Extent of Erosion: Minor
Location of Erosion | Erosion Dimensions | Eroded Material | Material Eroded | Total Erosion | ||
facing downstream | Length | Width | Depth | Reaching Stream? | (tons/year) | |
Left Ditch |
16 ft. |
18.5 ft. |
0.3 ft. |
yes |
Gravel |
0.0048 |
Left Ditch |
11 ft. |
5 ft. |
0.5 ft. |
no |
Sand |
0.0061 |
Summary Information
Fish Passability 0.5
A future visit to this site is recommended. To assess water velocity/ bridge is also extremely rusted
These non-native species were observerd at this site: Spotted Knapweed, Reed Canarygrass?