Highway Drainage Manual

This manual provides the design criteria for highway drainage. Hydrologic data for use with the Rational Method and SCS TR55 is included. Design charts and nomographs are included to assist in design computations.​ ​

Sections of the manual can be downloaded. Click on the links below.

  • Part I - Division of Highway Development (PDF 4.3 Mb)
  • Part II - Division of Bridge Development has been superseded by the "Manual for Hydrologic and Hydraulic Design" which is generally applicable where drainage areas exceed one square mile and for all bridge openings.
  • Part III - Environment Criteria and Procedures Bureau of Landscape Architecture
  • Part IV - Appendices
    1. Glossary (PDF 939 Kb)
    2. References (PDF 0.4 Mb)
    3. Design Charts - Have been mostly superseded by the various software programs
      1. Open Drainage Systems
        1. Conveyance Ditches and Channels - use FHWA Hydraulic Toolbox 
        2. Headwater - use Culvert Headwater Calculator (HDS-5) or FHWA HY-8
      2. Storm Drainage Systems
        1. Inlets and Gutters - use FHWA Hydraulic Toolbox
        2. Pipes - use approved software
      3. TR-20 Input Forms - use WinTR-20
      4. Design Forms (PDF 2 Mb)
    4. Design of Corrugated Metal and Aluminum Pipes (PDF 1.7 Mb)

Highway Drainage Manual Design Guidelines

The Design Guidelines supplement the Highway Drainage Manual and supersede all previously issued manuals, directives and guidelines.