Road Stream Crossing Site AB16
Alcona-Black River Watershed, Black River
US 23
Alcona County
Information collected by:
Site Location
GPS Coordinates: 44.77447201,-83.32426009
T 028N R 009 Sec 34
Fish Passability: Barrier at Most Flows
Structure is NOT Perched
Total Erosion: 1.17 tons/year
Overall Score: 14
Severity: Minor
Date Inventoried: 10/7/2022
Road Approach - Left
Road Approach - Right
Inlet
Upstream Conditions
Outlet
Downstream Conditions
Representative Reach
Site Sketch
Crossing Information*
Type of Crossing: Bridge
Number of Structures: 1
Structure Shape: Open Bottom Square/Rectangle
Inlet Type: Headwall
Outlet Type: Cascade Over Riprap
Structure Material: Concrete
Structure Substrate: Gravel
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 60 ft. Width 30 ft. Height 6.5 ft.
Percentage Plugged: None or 0%
Percentage Crushed: None or 0%
Structure is NOT Perched
Structure Inlet
Water Depth: 0.3 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.3 ft./sec.
Structure Outlet
Water Depth: 0.4 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.6 ft./sec.
*Water Velocities were measured 0.1 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? No
Is Upstream Ponding Present? No
Riffle Information
Water Depth: 0.8 ft.
Bankfull Width: 18.5 ft.
Wetted Width: 17.5 ft.
Water Velocity: 0.2 ft./sec. (measured via Flow Meter)
Dominant Substrate: Cobble – baseball-sized or larger rocks (10in)
Road Information
Road Surface: Paved
Owner: County
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: 40 ft.
Location of Low Point: At Stream
Runoff Path: Ditch
Embankments
Upstream
Fill Depth: 0 ft.
Slope: Steep, 1:1, 45°, or 100%
Downstream
Fill Depth: 0 ft.
Slope: Steep, 1:1, 45°, or 100%
Approaches
Left Approach
Length: 1000 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0.75 tons/year
Right Approach
Length: 615 ft.
Slope: 1-5%
Vegetation: Heavy, Ditch is fully vegetated or rip-rapped with no signs of erosion.
Erosion Estimate: 0.42 tons/year
Erosion Information
Estimate of Total Erosion at Crossing: 1.17 tons/year
Summary Information
Fish Passability: Barrier at Most Flows
Is a future visit to this site recommended? No
Were any non-native species observerd at this site? No
*These data are maintained in the Michigan DNR Road Stream Crossing Inventory.