Table of Contents
Culvert Hydraulics and Fish Passage Design Considerations
Culvert Hydraulics and Fish Passage Design Considerations Contents:
Determining Suitability
PPT Slide
Culvert Terminology
Potential Energy in Streams and Culverts
Hydraulic Provisions for Fish Passage
Velocity and Stream Flow
Hydrology and Design Flows
Oregon’s Fish Passage Design Flows: Maximum and Minimum
Using Fish Design Flows
Strategies to Manage Water Velocity
Culvert Placed Flat
Culvert Placed Flat (.5%) Assumptions
Issues with Culvert Placed Flat Designs
Strategies to Manage Water Velocity
Natural Stream with Roughness
Embedded Culvert
Mannings Equation and Roughness
Manning’s N vs. Flow based on Flume Derived Equations (for 10 foot diameter culvert with dmax 15 inches and stream slope 6%).
Relative Submergence
Thorne and Zevenbergen, 1985: Jour. Hyraul. Eng.
Thorne and Zevenbergen, 1985: Key Factors in the Equations
Variation of average velocity with flow for 10 foot diameter culvert with dmax 1 inch and slope 3%
Variation of average velocity with flow for 10 foot diameter culvert with dmax 6 inches and slope 3%
Variation of average velocity with flow for 10 foot diameter culvert with dmax 12 inches slope 3%
Strategies to Manage Water Velocity
Velocity Refuges in Culverts
Fish and Velocity Refuges
Velocity Refuges Inside Smooth Bottom Culverts
Velocity Refuges Inside Rough Bottom Culverts
Streambed Simulation
Streambed Simulation Culvert Designs: Assumptions
Streambed Simulation
Issues with Streambed Simulations Using Countersunk Culverts
“Seeded Culvert”
“Embedded Culvert”
Open Arches and Bridges and Streambed Simulation
Strategies to Manage Water Velocity
Backwatering Downstream Control
Backwatering with Weirs
Backwater Diagram – Critical Flow
Backwatering at Super Critical Flow
Baffle/Weir Culvert: Key Variables
Baffle/Weir Culvert Passage Criteria
Weir/Baffles Performance Example
Weir/Baffle Configurations
Hydraulic Provisions for Fish Passage
Outlet Drop
Inlet Drop
Inlet Velocity Changes
Inlet Drop Due to Constriction Longitudinal View
Hydraulic Provisions for Fish Passage
Backwatering from Outlet
Culvert Backwatering from Outlet
Backwatering Schematic for Rock Weirs
Depth from Bedforms
Culvert Alternatives Arrayed by Slope
Innovative Designs
Other Alternatives
Culvert Hydraulics and Fish Passage Design Considerations Conclusions
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