Revere Beach and Point of Pines, Massachusetts. SBEACH Version 2.0, in conjunction with other
analyses and methodologies, was applied to this project to: (a) determine protection provided at Re-
vere Beach by an existing coarse-grained beach fill, (b) evaluate coarse-grained beach and dune alter-
natives at Point of Pines (POP), and (c) predict volumes of water overtopping seawalls, revetments,
and dunes due to storms of various intensities along the entire project reach. The project area con-
sists of a crenulate-shaped bay shoreline, partially sheltered from wave attack by a large peninsula.
Revere Beach comprises the majority of the project reach, and is backed by concrete seawalls of
varying elevations fronted by a recently-placed coarse-grained beach fill. POP is at the downdrift end
of the littoral cell, and is characterized by native beach material backed by low dunes of varying
elevations. Between Revere and POP, a short native section of the shoreline is partially fronted by a
rubblemound revetment and seawall.
Calibration and verification data were available for two profiles at Revere, and one at POP for the
1991 "Halloween" storm, which impacted the study area from 27 October through 1 November. Pro-
file response at Revere indicated a uniform stripping of sediment during the storm, implying that
longshore sediment transport processes in that portion of the study area were influential in beach
response during the storm. This dominance of longshore transport precluded calibration and verifica-
tion of SBEACH for the Revere Beach portion of the study reach. However, for calculation of over-
topping volumes, SBEACH's wave transformation capabilities were deemed superior to other calcula-
tion methods planned by the U.S. Army Engineer New England Division, and SBEACH-calculated
waves and water levels were used as input to other analyses to predict overtopping volumes. At POP,
sediment was more nearly conserved between the pre- and post-Halloween storm profiles, thus allow-
ing model calibration (Figure 1). Profile change as well as nearshore waves and water levels were
predicted with SBEACH at POP. As part of the study, site-specific physical modeling tests of over-
topping were conducted to provide information, in addition to that available in the literature, to devel-
op a Runup and Overtopping Module (ROTM). The ROTM was applied in conjunction with
SBEACH output to predict overtopping rates on profiles backed by seawalls, revetments, or dunes as
a function of varying storm intensity. From 11 historical storms, a database of 50 synthetic storms
was created, and used as input to SBEACH to predict profile evolution (at POP), and calculate over-
topping rates (entire study reach).
The study concluded that the coarse-grained beach fill (0.49 mm median diameter) was highly effec-
tive in mitigating overtopping of the seawalls at Revere Beach, relative to the native beach condition
(consisting of sediment with median diameter 0.21 mm). These results were substantiated by observa-
tions of beach response and overtopping with the existing coarse fill in place at Revere during the
Halloween and December 1992 storms. Post-Halloween storm profiles at Revere used as input to
SBEACH were predicted to maintain a high level of flood protection, even after the observed
longshore loss of material. At POP, properly maintained dunes using the coarse fill material were
predicted to provide the necessary level of flood protection, with even a higher level of protection
than a revetment or revetment fronted by beach fill. The coarse fill provided more protection due to
the erosive resistance of the fill material, and the increased elevation of the design dunes (relative to
the design elevation of the revetment). Sensitivity testing indicated that grain sizes above 0.40 mm
were significantly more resistant to erosive waves, as compared to native beach material. Similar
results were found by Larson and Kraus (1989b) with eroded volumes decreasing significantly through
the range of 0.2 to 0.4 mm, and decreasing less noticeably above 0.40 mm. For additional study
findings, and more detailed presentation of study methodology, the reader is directed to Smith et al.
(1994).
Research applications. Hansen and Bymes (1991) applied SBEACH Version 1.0 using Ocean City,
Maryland profile, beach, and storm data to evaluate the storm protection provided by four different
CETN 9/94
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