Strengthening Your Bridge Program with Updated FHWA Guidelines

Bridge deterioration does not happen overnight—it happens gradually and often in places we can’t see. Below the waterline, bridge foundations face scour, corrosion, and deterioration. To help agencies detect and address these challenges, the Federal Highway Administration (FHWA) recently updated its Underwater Bridge Inspection Manual and Underwater Bridge Repair, Rehabilitation, and Countermeasures Reference Manual. At Consor, our underwater bridge inspectors don’t just use these resources—we help write them. Our team collaborated with FHWA on the updates, incorporating current safety protocols, inspection technologies, and standardized guidance on assessment, documentation, and repair for bridge owners, designers, and bridge inspectors.

For agencies and infrastructure owners, bridge preservation requires a structured, proactive approach to underwater bridge inspection and repairs. These manuals empower agencies to act early, address safety concerns, and prevent costly, unplanned closures. The FHWA mandates underwater bridge inspections at a minimum every 60 months, with more frequent evaluations for structures with higher deterioration concerns. Performed by bridge inspectors who are also divers, these assessments help detect early warning signs, guide repair decisions, and support long-term performance connectivity.

About The Author

Jeff Rowe, PE

Executive Vice President, Structural Assessment Executive Director

Jeff is a co-author of two FHWA Underwater Bridge Manuals. A nationally recognized, multi-year award-winning instructor, he brings 33 years of field experience—spanning thousands of underwater inspections—to his role as a lead trainer for the National Highway Institute (NHI). Jeff instructs the NHI 130091, 130091B, and 130078 courses.

Enhancing Asset Management with Underwater Bridge Inspections

The Underwater Bridge Inspection Manual is the foundation for the FHWA’s NHI-130091 course, which is required for divers conducting underwater bridge inspections. For agencies managing bridge inspection programs, this manual is an essential resource for maintaining consistent, federally compliant inspections that support long-term planning.

Dive inspector assessing a concrete pile.

Diver measuring the remaining section of a sacrificial anode.

Dive inspector measuring remaining steel thickness on a steel pile.

Key Updates & Why They Matter

Improved inspection protocols and diver safety standards – Aligns with advancements in diving technology to advance efficiency and safety.
Refined scour assessment methodologies – Incorporates 2D and 3D sonar imaging to provide agencies with clearer insights into foundation stability and deterioration risks.
Updated reporting and compliance requirements – Confirms agencies meet FHWA’s National Bridge Inspection Standards (NBIS) through more standardized and actionable documentation.

With these updates, agencies can enhance their bridge inspection programs, improve data-driven decision-making, and prioritize repairs more effectively. In addition to contributing to this manual, Consor’s experts teach the NHI-130091 course, helping inspectors nationwide apply these standards to real-world bridge conditions.

Diver using a hydraulic grinder to clean a steel pile before installing a repair.

Diver welding a steel patch plate on a steel pile.

Diver using a hydraulic coring machine to take (not rake) concrete core samples behind a steel retaining wall.

Key Updates & Why They Matter

Material selection guidance – Covers concrete, steel, timber, and composite applications to optimize repair durability based on environmental conditions.
Scour countermeasures – Outlines best practices for riprap placement, articulating concrete block systems, and foundation protection strategies.
Underwater welding, pile repair, and foundation strengthening – Provides clear methodologies for partial and full pile replacement to extend bridge lifespan.
Cathodic protection strategies – Helps agencies mitigate corrosion risks and reduce future maintenance costs.
Innovative repair techniques – Highlights in-the-wet construction and remotely operated vehicle (ROV) technologies for more efficient, cost-effective repairs.

By applying the guidance in these manuals, agencies can take a proactive approach to bridge preservation—extending service life, optimizing maintenance budgets, and maintaining safer infrastructure for their communities.

Connect with an Expert

For technical questions about FHWA’s Underwater Bridge Inspection Manual and Underwater Bridge Repair, Rehabilitation, and Countermeasure Manual, contact me, Jeff Rowe. As a co-author of the manual and a lead instructor for multiple National Highway Institute courses, I offer deep subject matter expertise to support your program’s development and implementation efforts.