Coastal Construction Manual - National Ready Mixed Concrete ...

IDENTIFYING HAZARDS 3
Building codes and standards—and FEMA building science publications—refer to the Coastal A Zone
and have specific requirements or recommendations for design and construction in this zone. Post-disaster
damage inspections consistently show the need for such a distinction. Figure 3-53 shows how the Coastal A
Zone can be inferred from FIS transects and maps.
NOTE
Detailed FEMA coastal mapping guidance is
contained in Appendix D of Guidelines and
Specifications for Flood Hazard Mapping Partners
(FEMA 2003). Designers need not be familiar with
all of these guidelines, but they may be useful
on occasion. Appendix D is divided into several
documents, one for the Atlantic and Gulf of
Mexico coasts, one for the Pacific coast, and one
for the Great Lakes coast. These documents have
been and continue to be updated and revised,
so designers should refer to the FEMA mapping
Web site for the latest versions: http://www.fema.
gov/plan/prevent/fhm/dl_vzn.shtm#3. Guidance
on mapping the LiMWA is contained in Procedure
Memorandum No. 50 at http://www.fema.gov/
library/viewRecord.do?id=3481.
3.6.4 Wave Heights and Wave Crest Elevations
FEMA’s primary means of establishing BFEs and distinguishing
between Zone V, Zone A, and Zone X is wave height. Wave
height is simply the vertical distance between the crest and
trough of a wave propagating over the water surface. BFEs in
coastal areas are usually set at the elevation of the crest of the
wave as it propagates inland.
The maximum wave crest elevation (used to establish the BFE)
is determined by the maximum wave height, which depends
TERMINOLOGY:
WAVE HEIGHT
Wave height is the vertical
distance between the wave crest
and wave trough (see Figure
3-55). Wave crest elevation is the
elevation of the crest of a wave,
referenced to the NGVD, NAVD,
or other datum.
COASTAL CONSTRUCTION MANUAL
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