Assessment of Allowable Headwater Design Criteria for Large Culverts

About the project:

Culvert failures are a safety, economic, and operational concern across the US. Culverts are designed to last for more than 20 years which can result in culverts becoming undersized and failing due to changing rainfall patterns, insufficient maintenance, and increases in impervious surface due to new land development.  Larger storm events and increased land development can lead to more runoff than originally anticipated and result in unexpectedly high culvert headwaters. Culverts are designed based on the ratio of headwater at the culvert entrance to its diameter during a given design storm. High culvert headwaters relative to the culvert diameter can lead to culvert failures which can cause flooding and property damage. Given the vulnerability of culverts to failure and the potentially significant impact of culvert failures, there is a need to review other state practices and national guidance on culvert design as well as investigate if VDOT has sufficient data to determine root causes of culvert failures across the state. This research will document design practices, specifically the ratio of headwater to diameter and design storm size, from other state DOTs as well as investigate the availability of culvert failure data for Virginia. This will enable VDOT to improve culvert design or management and thus may prevent future culvert failures. 

Project Team

Principal Investigators