3. Assessment of Coastal Change 



This chapter describes the regional beach and nearshore response to waves and storms that 

 occur along the coast of Brevard County, with focus on the properties of the test plaintiffs. 

 Historical shoreline, beach profile, and bathymetry data sets are analyzed to document coastal 

 evolution prior to and after construction of Canaveral Harbor. These data represent the primary 

 sources of information for quantifying the impact of Harbor construction on property downdrift 

 of the jetties. Data collected by the FDEP, the USC&GS (now NOS), and the USACE are the 

 foundation upon which objective evaluations are made for assessing impacts at the properties of 

 the test plaintiffs. 



3.1. Data Sources 



Three sources of data were analyzed for quantifying shoreline-position change that has 

 occurred along the coast of Brevard County for the period of record (1875 to 1998). Historical 

 shoreline data sets from the NOS and a May 1996 shoreline surveyed using GPS technology 

 established a consistent record of continuous measurements along the coast at an interpreted 

 HWL (Table 3-1). FDEP and USACE beach-profile survey data were analyzed to determine 

 cross-shore change in beach shape. 



Beach-profile survey data document short-term shoreline change at a 1,000-ft longshore 

 spacing. NOS hydrographic data sets from 1929 and 1956 surveys, bounded on the landward 

 side with the 1928 and 1948 NOS shoreline surveys, documented beach and nearshore sand 

 volume changes prior to Harbor construction. Also, a hydrographic survey conducted for this 

 study by the USACE (May 1996), together with the 1996 GPS shoreline survey, shows the beach 

 and nearshore change resulting from Harbor construction. 



The Canaveral Harbor entrance and jetties were constructed over the period June 1951 to 

 September 1954 (see the chronology in Table 2-1 and Appendix F). Immediate post-construction 

 bathymetric survey data are not available to define morphologic adjustments after construction of 

 the north Harbor entrance jetty. As a replacement, the 1948 NOS shoreline survey provided a 

 surrogate landward boundary of the bathymetric surface to document beach and nearshore change 

 prior to Harbor construction. As such, the available 1929 and 1956 NOS hydrographic surveys 

 primarily documented pre-construction adjustments in sand volume north of the Harbor. 



All coastal morphology data sets contain errors that are related to measurement technique, 

 map scale, and digital data-compilation and analysis procedures. In this study, to judge the 

 significance of measured rates of beach and shoreline change, potential errors are quantified and 

 compared with measurements. In considering all potential inherent errors associated with data 

 compilation and analysis, it is recognized that these apply to each individual data set. In making 

 comparisons of shoreline-position and bathymetric change, errors in measurement and technique 



Chapter 3 Assessment of Coastal Change 3-'| 



