Drainage Manual Update
By: Erik Brenna, State Aid Hydraulics Engineer
The MnDOT Hydraulics Unit has undergone efforts to update the Drainage Manual. This is the technical manual that provides statewide hydraulic design guidance for culverts, channels, and bridges. State Aid hydraulic guidance from Chapter 5.5 of the State Aid Manual points the reader to the Drainage Manual for a deeper technical dive into hydraulic design parameters that pertain to county and city designs.
Chapters 1-3 and Appendices B-D are now live on this site, Drainage Manual - Hydraulics - MnDOT.
Updates include:
- Chapter 1: Introduction
- Updates to background info and documentation needs
- Chapter 2: Pipe Materials (previously titled “Materials and Structural Design”)
- Technical memos incorporated
- Pipe bedding details moved to standard plans
- Updates to pipe material design considerations
- Chapter 3: Hydrology
- Technical memos incorporated
- Resiliency check storms incorporated
- Appendix B – Atlas 14 24hr Precipitation Depth by County (previously “Rainfall Intensity Curves”)
- Appendix C – Corrugated Steel Pipe Service Life (previously “Pipe Flow Design Charts”)
- Appendix D – Hard Conversion of Pipe Diameters from English to Metric (previously “Open Channel Flow Charts”)
For full information on the content changes see Transmittal 24-01 (PDF). By early Fall 2024 we expect the remainder of the MnDOT Drainage Manual to be complete. The 2024 updates will supersede the 2000 version of the Drainage Manual. Interested readers can sign up for future updates at this link:
If you have any comments on content please submit them to hydraulic.standards@dot.mn.us.
Thank you!