Road Stream Crossing Site EUP_PRW18
Pine River Watershed, Garden Hill Creek
Mackinac Trail
Mackinac County
Information collected by:
Site Location
GPS Coordinates: 46.1059296,-84.6512759
T 043N R 003 Sec 23
Fish Passability: Barrier
Structure is NOT Perched
Total Erosion: 2.31 tons/year
Overall Score: 17
Severity: Severe
Date Inventoried: 4/28/2021
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: Open Bottom Square/Rectangle
Inlet Type: Wingwall Greater than 70 degrees
Outlet Type: Cascade Over Riprap
Structure Material: Concrete
Structure Substrate: Mixture
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? Yes
Dimensions of Structure: Length 52 ft. Width 8 ft. Height 6 ft.
Percentage Plugged: None or 0%
Percentage Crushed: None or 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 0.5 ft.
Embedded Depth of Structure: 0.5 ft.
Water Velocity*: 2.2 ft./sec.
Structure Outlet
Water Depth: 0.6 ft.
Embedded Depth of Structure: 0.1 ft.
Water Velocity*: 4 ft./sec.
*Water Velocities were measured 0.4 ft. below the surface (via Flow Meter).
Stream Information
Stream Flow: < Bankfull – The stream channel is more than half filled with water, but is not full.
Stream Flow Type: Perennial (if flowing during the time of assessment.)
Is Scour Pool Present? No
Is Upstream Ponding Present? No
Riffle Information
Water Depth: 0.6 ft.
Bankfull Width: 7 ft.
Wetted Width: 5.4 ft.
Water Velocity: 0.9 ft./sec. (measured via Flow Meter)
Dominant Substrate: Gravel – rocks between the size of a pinhead and a baseball
Road Information
Road Surface: Paved
Owner: State
Road Condition: New Pavement or Well Graded, Same condition as initial placement.
Road Core Integrity: Good (no symptoms of lack of integrity)
Road Width at Culvert: 35 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Embankments
Upstream
Fill Depth: 2.6 ft.
Slope: Moderate, 2:1, 22.5°, or 41%
Downstream
Fill Depth: 2.6 ft.
Slope: Moderate, 2:1, 22.5°, or 41%
Approaches
Left Approach
Length: 760 ft.
Slope: 6-10%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 1.65 tons/year
Right Approach
Length: 1000 ft.
Slope: 6-10%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0.66 tons/year
Erosion Information
Estimate of Total Erosion at Crossing: 2.31 tons/year
Summary Information
Fish Passability: Barrier
Is a future visit to this site recommended? No
Were any non-native species observerd at this site? Yes, Spotted knapweed.
*These data are maintained in the Michigan DNR Road Stream Crossing Inventory.