PWA - Project Detail - FEMA Guidelines for Coastal Flood Hazard Analysis and Mapping

PWA led several key technical areas: wave transformations, wave runup and overtopping of shores and shore structures. PWA also conducted several key technical “Focus Studies” that supported the development of the Guidelines. One evaluated alternative means to characterize the 0.01 annual probability coastal flood event (aka, the 100-year event), in terms of joint occurrence of high wind waves and high water levels. Alternative approaches included “Event Selection,” defined by the joint probability of the forcing parameters (water levels and waves), and “Time Series” analysis (either real or simulated with Monte Carlo methods) of the response parameter (wave run-up elevation). Another focus study evaluated alternative methods for calculating wind wave generation typically used in Sheltered Waters, such as San Francisco Bay and Puget Sound. Under contract with FEMA Region IX, Northwest Hydraulics Consultants (NHC) led the work. As a member of the team led by NHC / FEMA, PWA worked through a broad array of technical issues in a collaborative manner.

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Title		FEMA Guidelines for Coastal Flood Hazard Analysis and Mapping
Project Summary		PWA played a key role in revising the FEMA guidelines for the mapping of coastal hazards on the Pacific Coast, and led focused technical studies on wave transformation, wave run-up, and overtopping of structures.

Location		U.S. Pacific Coast
Client		Northwest Hydraulics Consultants & FEMA Region IX

Project Detail		PWA participated in the evaluation and update of the Federal Emergency Management Agency's (FEMA) Guidelines and Specifications for mapping of coastal flood hazards for the Pacific Coast of the United States. PWA led several key technical areas: wave transformations, wave runup and overtopping of shores and shore structures. PWA also conducted several key technical “Focus Studies” that supported the development of the Guidelines. One evaluated alternative means to characterize the 0.01 annual probability coastal flood event (aka, the 100-year event), in terms of joint occurrence of high wind waves and high water levels. Alternative approaches included “Event Selection,” defined by the joint probability of the forcing parameters (water levels and waves), and “Time Series” analysis (either real or simulated with Monte Carlo methods) of the response parameter (wave run-up elevation). Another focus study evaluated alternative methods for calculating wind wave generation typically used in Sheltered Waters, such as San Francisco Bay and Puget Sound. Under contract with FEMA Region IX, Northwest Hydraulics Consultants (NHC) led the work. As a member of the team led by NHC / FEMA, PWA worked through a broad array of technical issues in a collaborative manner.