Road Stream Crossing Site EUP_MCW18
Les Cheneaux Islands Watershed, Flowers Creek
S Flowers Bay Road
Mackinac County
Information collected by:
Site Location
GPS Coordinates: 45.9994793,-84.3218164
T 042N R 001 Sec 32
Fish Passability: Barrier at High Flows
Structure is NOT Perched
Total Erosion: 3.11 tons/year
Overall Score: 26
Severity: Moderate
Date Inventoried: 5/14/2021
Road Approach - Left
Road Approach - Right
Inlet
Upstream Conditions
Outlet
Downstream Conditions
Representative Reach
Site Sketch
Crossing Information*
Type of Crossing: Culvert(s)
Number of Structures: 1
Structure Shape: Native Bottom Arch
Inlet Type: Projecting
Outlet Type: At Stream Grade
Structure Material: Metal
Structure Substrate: Sand
General Conditions: Light superficial corrosion or abrasion or chipping or spalling or cracking. No shape changes (described above).
Structure Interior: Smooth
Is Structure Rusted through? No
Dimensions of Structure: Length 33 ft. Width 8 ft. Height 4 ft.
Percentage Plugged: None or 0%
Percentage Crushed: None or 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 1.6 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 0.5 ft./sec.
Structure Outlet
Water Depth: 1.6 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 0.2 ft./sec.
*Water Velocities were measured 1.4 ft. below the surface (via Flow Meter).
Stream Information
Stream Flow: < 1/2 Bankfull – The stream channel is less than half filled with water.
Stream Flow Type: Perennial (if flowing during the time of assessment.)
Is Scour Pool Present? Yes
Scour Pool: Length 15 ft., Width 10 ft., Depth 2 ft.
Is Upstream Ponding Present? Yes
Pond: Length 12 ft., Width 10 ft.
Riffle Information
Water Depth: 0.5 ft.
Bankfull Width: 16.8 ft.
Wetted Width: 11 ft.
Water Velocity: 1.3 ft./sec. (measured via Flow Meter)
Dominant Substrate: Clay – very fine particles that stick together
Road Information
Road Surface: Gravel
Owner: County
Road Condition: Old Pavement or Rutted, Minor cracking or rutting/ponding at crossing all or part of crossing length.
Road Core Integrity: Good (no symptoms of lack of integrity)
Road Width at Culvert: 19 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Embankments
Upstream
Fill Depth: 4.4 ft.
Slope: Steep, 1:1, 45°, or 100%
Downstream
Fill Depth: 3.6 ft.
Slope: Steep, 1:1, 45°, or 100%
Approaches
Left Approach
Length: 50 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0.09 tons/year
Right Approach
Length: 900 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 2.64 tons/year
Erosion Information
Estimate of Total Erosion at Crossing: 3.11 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 | 2 ft. | 8 ft. | 3.5 ft. | Yes | Gravelly Loam | Severe (corrective actions recommended) | 0.38 |
Summary Information
Fish Passability: Barrier at High Flows
Is a future visit to this site recommended? No
Were any non-native species observerd at this site? Yes, Spotted knapweed, mullein.
Site Comments: Poor culvert alignment
*These data are maintained in the Michigan DNR Road Stream Crossing Inventory.