Road Stream Crossing Site EUP_41N4W25_001
Les Cheneaux Islands Watershed, Unnamed
Mackinac Trail/Co Rd H63
Mackinac County
Information collected by:
HNF USFS
Site Location
GPS Coordinates: 45.911970577,-84.738588996
T 041NN R 004W Sec 25
Fish Passability: Barrier at High Flows
Structure is NOT Perched
Overall Score: 20
Severity: Moderate
Date Inventoried: 8/14/2018
Crossing Information*
Type of Crossing: Culvert(s)
Structure Shape: Round
Inlet Type: Apron
Outlet Type: At Stream Grade
Structure Material: Concrete
Structure Substrate: Sand
General Conditions: Moderate deterioration from corrosion or abrasion (small rust flakes or indication that rust is slightly deeper than the surface level) or cracking or spalling or chipping (few minor cracks or localized chipping in the concrete). OR minor shape changes (described above).
Structure Interior: Smooth
Is Structure Rusted through? No
Dimensions of Structure: Width 5 ft. Height 5 ft.
Percentage Plugged: 41% - 60% Inlet
Percentage Crushed: None or 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 0.9 ft.
Embedded Depth of Structure: 0.01 ft.
Water Velocity*: 0 ft./sec.
Structure Outlet
Water Depth: 0.37 ft.
Embedded Depth of Structure: 1 ft.
Water Velocity*: 0 ft./sec.
Stream Information
Stream Flow: < 1/2 Bankfull – The stream channel is less than half filled with water.
Riffle Information
Water Depth: 0.22 ft.
Bankfull Width: 11.42 ft.
Wetted Width: 3.4 ft.
Water Velocity: 2.09 ft./sec. (measured via Float Test)
Dominant Substrate: Gravel – rocks between the size of a pinhead and a baseball
Road Information
Road Surface: Paved
Owner: County
Road Condition: New Pavement or Well Graded, Same condition as initial placement.
Location of Low Point: Other
Runoff Path: Roadway
Embankments
Upstream
Fill Depth: 4.8 ft.
Slope: Gentle, 3:1, 15°, or 33%
Downstream
Fill Depth: 5.4 ft.
Slope: Steep, 1:1, 45°, or 100%
Approaches
Left Approach
Length: 1000 ft.
Slope: < 1%
Vegetation: Partial, Ditch has some vegetation and some bare, eroding places.
Right Approach
Length: 1000 ft.
Slope: < 1%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Information
Location of Erosion | Erosion Dimensions | Eroded Material | Material Eroded | Extent of Erosion | Estimated Erosion | ||
facing downstream | Length | Width | Depth | Reaching Stream? | (tons/year) | ||
Right Upstream Ditch | 19.2 ft. | 12 ft. | 4 ft. | Yes | Gravel | Minor | |
Summary Information
Fish Passability: Barrier at High Flows
Were any non-native species observerd at this site? Yes, Spotted Knapweed.
Site Comments: Erosion also a priority at this site. Large blockage/narrowing at inlet and outlet.Lots of sand in outlet side, stream narrows becuase of this.
*These data are maintained in the Michigan DNR Road Stream Crossing Inventory.