Road Stream Crossing Site EUP_6336645119
Carp River Watershed, South branch carp river
Town line road
Mackinac County
Information collected by:
Superior Watershed Partnership
Site Location
GPS Coordinates: 46.086331489,-84.9894074169999
T 043NN R 006W Sec 25
Fish Passability: Barrier
Structure is NOT Perched
Total Erosion: 6.3 tons/year
Date Inventoried: 6/10/2020
Crossing Information*
Type of Crossing: Other
Number of Structures: 1
Structure Shape: Other
Inlet Type: Other
Outlet Type: Other
Structure Material: Other
Structure Substrate: Sand
General Conditions: Severe deterioration from corrosion or abrasion (more than 50% of the structure is rusted through) or cracking or spalling or chipping (more than 50% of the structure is compromised). Or Major shape changes (described above) reducing the capacity of the structure by greater than 50%. OR Segment disconnect causing major subsurface erosion/piping and/or partial fill failure and/or sink holes in the fill.
Is Structure Rusted through? No
Dimensions of Structure: Length 8 ft. Width 0 ft. Height 0 ft.
Percentage Plugged: None or 0%
Percentage Crushed: None or 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 0 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.667 ft./sec.
Structure Outlet
Water Depth: 0 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.667 ft./sec.
*Water Velocities were measured 1.1 ft. below the surface (via Float Test).
Stream Information
Stream Flow: < Bankfull – The stream channel is more than half filled with water, but is not full.
Is Scour Pool Present? Yes
Scour Pool: Length 65 ft., Width 60 ft., Depth 7 ft.
Is Upstream Ponding Present? Yes
Pond: Length 18 ft., Width 7 ft.
Riffle Information
Water Depth: 2 ft.
Bankfull Width: 25 ft.
Wetted Width: 22 ft.
Water Velocity: 0.7 ft./sec. (measured via Float Test)
Dominant Substrate: Sand – particles are smaller than a pinhead and feel gritty between fingers
Road Information
Road Surface: Native Surface
Owner: Other
Road Condition: Broken Pavement or Rilled/Gullied, Multiple patches, cracks, rilling, or gullies at crossing.
Location of Low Point: At Stream
Runoff Path: Roadway
Embankments
Upstream
Fill Depth: 0 ft.
Downstream
Fill Depth: 0 ft.
Approaches
Left Approach
Length: 300 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0 tons/year
Right Approach
Length: 200 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0 tons/year
Erosion Information
Estimate of Total Erosion at Crossing: 6.3 tons/year
Location of Erosion | Erosion Dimensions | Eroded Material | Material Eroded | Extent of Erosion | Estimated Erosion | ||
facing downstream | Length | Width | Depth | Reaching Stream? | (tons/year) | ||
Left Upstream Ditch | 5 ft. | 11 ft. | 5 ft. | Yes | Loam | Severe (corrective actions recommended) | 4.84 |
Left Downstream Embankment | 5 ft. | 4.5 ft. | 3 ft. | Yes | Sandy Loam | Moderate (corrective actions recommended) | 0.45 |
Left Upstream Embankment | 4.5 ft. | 5 ft. | 3.5 ft. | Yes | Loam | Moderate (corrective actions recommended) | 0.49 |
Left Approach | 5.5 ft. | 4.5 ft. | 3 ft. | Yes | Gravel | Moderate (corrective actions recommended) | 0.52 |
Summary Information
Fish Passability: Barrier
Is a future visit to this site recommended? Yes, A lot of sediment erosion into stream. Too narrow of old bridge crossing area causes upstream pool, large scour pools and too high of water velocity for fish passage.
Were any non-native species observerd at this site? Yes
Site Comments: Site of an old bridge.
*These data are maintained in the Michigan DNR Road Stream Crossing Inventory.