Synthesis of Information Related to Highway Practices. Topic 55-18. Permitting, Design, and Construction Practices for Aquatic Organism Passage

State departments of transportation (DOTs) have traditionally designed structures to convey water under roads based on cost, hydraulic efficiency, and risk criteria. However, this design approach can result in barriers to aquatic organism passage (AOP) as an unintended and undesired consequence. Thus, state DOTs have come under increasing regulatory direction to ensure AOP through structures. State DOTs on the West Coast and in the Northeast have been dealing with AOP for some time now, initially motivated by state and federal regulatory requirements, and now sometimes by legal challenge. Design practice in these state DOTs has settled on a suite of generally accepted approaches and practices calling for a higher level of geomorphic and hydraulic design than was formerly the case. Modern AOP design typically entails an interdisciplinary approach relying on various combinations of hydraulic engineers, hydrologists, fluvial geomorphologists, and biologists. As a result of AOP design, structures have gotten larger, streambed placement and construction is now a routine practice, and 3-sided and open-bottom structures are strongly encouraged by regulators and resource agencies. Project scopes and costs have increased as compared to traditional hydraulic capacity designs. Some state DOTs have elected to address AOP programmatically while others have proceeded on a project-by-project basis. Along with these challenges has come that of institutional capacity. State DOT staffs may not have the numbers, skills, or experience, nor do many of the consultants who have traditionally functioned as extensions of DOT staffs. The objective of this synthesis is to document state DOT practices and activities in designing, constructing, and monitoring structures that deliver aquatic organism passage.


  • English


  • Status: Active
  • Funding: $55000
  • Contract Numbers:

    Project 20-05, Topic 55-18

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Gause, Jo

  • Performing Organizations:

    ,   Germany 


    One Penn Plaza
    250 W 34th Street
    New York, New York  United States  10119
  • Principal Investigators:

    Lennon, Justin

  • Start Date: 20231019
  • Expected Completion Date: 20250419
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01887173
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-05, Topic 55-18
  • Files: TRB, RIP
  • Created Date: Jul 10 2023 9:22PM