Hydraulic Engineering Circular No. 25 – Volume 2: Highways in the Coastal Environment: Assessing Extreme Events

Title: Hydraulic Engineering Circular No. 25 – Volume 2: Highways in the Coastal Environment: Assessing Extreme Events
Author: FHWA
Publication Date: October 2014
Dewey Decimal Number: 388.12
Call Record: DIGITAL      388.12  FHWA  2014


Highways in the Coastal Environment: Assessing Extreme Events
Cover of Highways in the Coastal Environment: Assessing Extreme Events

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National Technical Information Service

5301 Shawnee Road
Alexandria, VA 22312 United States


This manual provides technical guidance and methods for assessing the vulnerability of coastal transportation facilities to extreme events and climate change. This is a standalone supplement, a “Volume 2,” to the existing, primary Federal Highway Administration (FHWA) Hydraulic Engineering Circular (HEC) manual: “Highways in the Coastal Environment,” HEC-25 (2nd edition, FHWA 2008). The focus of this supplement is quantifying exposure to sea level rise, storm surge, and waves considering climate change. It is anticipated that there will be multiple uses for this guidance including risk and vulnerability assessments, planning activities, and design procedure development. The critical coast processes controlling the vulnerability of transportation assets to extreme events are identified by region along with some available methods for modeling them and the likely impacts of climate change. Global sea level rise, including projections of future sea levels, is emphasized because of its importance. Tools for developing vulnerability assessments for coastal transportation infrastructure are described within the framework of engineering risk. Storm damage mechanisms, often exacerbated by sea level rise and climate change, are described. Adaptation approaches for coastal transportation infrastructure are also described. Many of the adaptations required for climate change and sea level rise are the same adaptations required for improving infrastructure resilience to extreme events with today’s sea levels. Specific approaches for assessing exposure of coastal infrastructure to extreme events and climate change are presented in three different “levels of effort” ranging from use of available data to original numerical modeling. The inclusion of trained coastal scientists and engineers in the analysis team is suggested at all levels of effort. Three case studies from the existing literature on coastal vulnerability assessments to extreme events and climate change are described. Coastal transportation infrastructure is highly exposed to extreme events today and that exposure is likely to increase with sea level rise and climate change.

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Corporate Authors:

Kilgore Consulting & Management

2963 Ash Street
Denver, CO 80207 United States

South Coast Engineers

PO Box 72
Fairhope, AL 36533 United States


Douglass, Scott L
Webb, Bret M
Kilgore, Roger



Publication Date:



Hydraulic Engineering Circular

Issue Number: 25 (Volume 2)
Publisher: Federal Highway Administration

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Appendices; Figures; Glossary; Maps; References; Tables

Subject Areas:

Environment; Highways; Planning and Forecasting; Transportation (General); I15: Environment; I72: Traffic and Transport Planning