Road Stream Crossing Site AUS_CR081

Au Sable River Watershed, North Branch Au Sable River
Twin Bridge Rd
Lovells Twp, Crawford County
Information collected by:
Huron Pines
Site Location
GPS Coordinates: 44.82761 , -84.49041
T28N R02W Sec 13
Owned by Private
Fish Passability 0
Structure is NOT Perched
Total Erosion: 1.5958 tons/year
Severity: Severe
Year Inventoried: 2013
Crossing Information
Type of Crossing: culvert(s)
Number of Structures: 4
Structure Shape: Ellipse
Inlet Type: Mitered
Outlet Type: At Stream Grade
Structure Material: Metal
Structure Substrate: Gravel
General Conditions: Good
Multiple Culverts/Spans
Culvert/Span
Width
Length
Height
Material
1
17 ft.
53 ft.
6.6 ft.
Metal
3
10 ft.
52.5 ft.
6.9 ft.
Metal
4
10 ft.
52.5 ft.
6.8 ft.
Metal
Structure Interior: corrugated
Dimensions of Structure: Length 53 ft. , Width 17 ft. , Height 6.6 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 1.7 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 3.6 ft./sec.
Structure Outlet
Water Depth: 1.2 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 5.56 ft./sec.
*Water Velocities were measured at the Surface (with Float Test)
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 62 ft. , Width 76 ft. , Depth 2.3 ft.
Upstream Pond: Length 0 ft. , Width 0 ft. , Depth 0 ft.
Riffle Information
Water Depth: 1.2 ft.
Bankfull Width: 109 ft.
Wetted Width: 97.5 ft.
Water Velocity: 3 ft./sec. (Measured with Float Test)
Dominant Substrate: Gravel
Road Information
Paved County Road
Road Condition: Poor
Road Width at Culvert: 26 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Embankments
Upstream
Fill Depth: 2.2 ft.
Slope: 1:2
Downstream
Fill Depth: 2 ft.
Slope: 1:2
Approaches
Left Approach
Length: 1000 ft.
Slope: 1% to 5%
Vegetation: Partial
LS Factor: 0.8
Erosion: 0.6876 tons/year
Right Approach
Length: 1000 ft.
Slope: 1% to 5%
Vegetation: Partial
LS Factor: 0.8
Erosion: 0.6876 tons/year
Erosion Information
Total Erosion at Crossing: 1.5958 tons/year
Extent of Erosion: Moderate
Notes: Mostly foot traffic, cement barrier is cracking, and 2 cement/cracked walkways
Location of Erosion
Erosion Dimensions
Eroded Material
Material Eroded
Total Erosion
facing downstream
Length
Width
Depth
Reaching Stream?
(tons/year)
Right Downstream
68 ft.
4.5 ft.
0.3 ft.
yes
Sand
0.1571
Right Ditch
11 ft.
2 ft.
0.2 ft.
yes
Silt
0.0131
Left Downstream
15 ft.
6 ft.
0.5 ft.
yes
Sandy Loam
0.0504
Summary Information
Fish Passability 0
Fish Passage is an area of concern for this site. High velocity water, deteriorating cement barrier and structure.
A future visit to this site is recommended. Realignment/replacement of bridge is severely needed. Replacement of cement barrier might also be needed.
These non-native species were observerd at this site: Spotted Knapweed, Queen Anne's Lace