Road Stream Crossing Site BEAR_BC044
Bear Creek Watershed, Big Bear Creek
11 Mile
Maple Grove Twp,
Manistee County
Information collected by:
Site Location
GPS Coordinates: 44.39919
, -86.04866
T23N
R14W
Sec 7
Owned by Private
Structure is NOT Perched
Total Erosion: 10.0496 tons/year
Severity: Moderate
Year Inventoried: 2011
Inlet
Outlet
Upstream Conditions
Downstream Conditions
Road Approach - Left
Road Approach - Right
Crossing Information
Type of Crossing: Bridge
Structure Shape: Open Bottom Square/Rectangle
Inlet Type: Wingwall 30-70 Degree
Outlet Type: At Stream Grade
Structure Material: Wood
Structure Substrate: Mixture
General Conditions: Good
Structure Interior: smooth
Dimensions of Structure: Length 32 ft.
, Width 30 ft.
, Height 12 ft.
Structure is NOT Perched
Structure Inlet
Water Depth: 2.05 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.2 ft./sec.
Structure Outlet
Water Depth: 2.15 ft.
Embedded Depth of Structure: 0 ft.
Water Velocity*: 2.3 ft./sec.
*Water Velocities were measured 1.23 ft. below Surface
(with Meter)
Additional Comments
The right approach has 95ft of pavement and the remaining section is gravel. The left approach is 70ft of pavement and the remaining section is gravel. Gravel and sand is washing over bridge directly into the stream.
Stream Information
Stream Flow: Less than Bankfull
Scour Pool: Length 60 ft.
, Width 45 ft.
, Depth 3 ft.
Riffle Information
Water Depth: 1.41 ft.
Bankfull Width: 52.3 ft.
Wetted Width: 48.8 ft.
Water Velocity: 2.7 ft./sec.
(Measured with Meter)
Dominant Substrate: Gravel
Road Information
Paved
County Road
Road Condition: Fair
Road Width at Culvert: 27 ft.
Location of Low Point: At Stream
Runoff Path: Roadway
Fill Depth: 0 ft.
Slope: Vertical
Fill Depth: 0 ft.
Slope: Vertical
Approaches
Left Approach
Length: 525 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.57
Erosion: 5.0248 tons/year
Right Approach
Length: 625 ft.
Slope: 1% to 5%
Vegetation: Heavy
LS Factor: 0.57
Erosion: 5.0248 tons/year
Erosion Information
Total Erosion at Crossing: 10.0496 tons/year
Extent of Erosion: Minor
Erosion is occurring and corrective actions can be installed to address the problem.
Notes:
Road runoff from gravel section of road is reaching stream from bridge.
Summary Information
Erosion is an area of concern for this site.