Road Stream Crossing Site AUS_RO007
Au Sable River Watershed, South Branch Au Sable River
North Keno Rd
AuSable Twp,
Roscommon County
Information collected by:
Site Location
GPS Coordinates: 44.48161
, -84.45107
T24N
R01W
Sec 9
Owned by Private
Fish Passability 1
Structure is NOT Perched
Total Erosion: 8.6781 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: Sand
General Conditions: Good
Structure Interior: smooth
Dimensions of Structure: Length 47 ft.
, Width 45 ft.
, Height 8.5 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 2.2 ft.
Water Velocity*: 0.74 ft./sec.
Structure Outlet
Water Depth: 2.3 ft.
Water Velocity*: 0.8 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: 2.8 ft.
Bankfull Width: 38 ft.
Wetted Width: 28 ft.
Water Velocity: 0.55 ft./sec.
(Measured with Float Test)
Dominant Substrate: Sand
Road Information
Paved
County Road
Road Condition: Good
Road Width at Culvert: 33 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Approaches
Left Approach
Length: 1000 ft.
Slope: 6% to 10%
Vegetation: Partial
LS Factor: 3.15
Erosion: 3.4364 tons/year
Right Approach
Length: 1000 ft.
Slope: 1% to 5%
Vegetation: Partial
LS Factor: 0.8
Erosion: 0.8727 tons/year
Erosion Information
Total Erosion at Crossing: 8.6781 tons/year
Extent of Erosion: Severe
Erosion is occurring and corrective actions can be installed to address the problem.
Notes: severe erosion along downstream side
Location of Erosion | Erosion Dimensions | Eroded Material | Material Eroded | Total Erosion | ||
facing downstream | Length | Width | Depth | Reaching Stream? | (tons/year) | |
Right Downstream |
77 ft. |
12 ft. |
3 ft. |
yes |
Silt |
3.927 |
Right Streambank |
13 ft. |
9 ft. |
2 ft. |
yes |
Silt |
0.442 |
Summary Information
Fish Passability 1
Erosion is an area of concern for this site.
Severe erosion (silt) downstream from bridge
A future visit to this site is recommended. Install silt fences
These non-native species were observerd at this site: Spotted Knapweed