ENVIRONMENTAL ASSESSMENT OF BEACH NOURISHMENT PROJECTS CONSTRUCTED WITH BENEFICIAL USE OF DREDGE MATERIAL IN PALM BEACH COUNTY, FLORIDA

Sourcing sediment from adjacent inlets for placement on eroded downdrift beaches is an increasingly common practice, as an inlet sources’ proximity to a placement site reduces the transportation cost of a project and is considered a beneficial use of the dredge material (BUDM). This project aimed to compare two nourishment projects using adjacent inlet sediment sources for changes in water quality, morphology, and sedimentology at two geographically similar locations in southeast Florida. In 2023, Jupiter Beach Park (Jupiter, FL) and South Inlet Park Beach (Boca Raton, FL) were nourished using sediment from the adjacent inlet system. Jupiter was nourished with sediment from the inlet’s sand trap and Boca Raton was nourished with sediment from the ebb shoal. Suspended sediment concentration (SSC) in the water column is closely associated with other properties of water including temperature, salinity, and dissolved oxygen.
A sudden increase in suspended sediment in nearshore water can be triggered by anthropogenic activity, like nourishment, as well as natural occurrences, like storms. Sampling began prior to the initiation of nourishment (February) and continued throughout hurricane season (May – November). Sediment samples were analyzed for moment method statistics (i.e., mean, standard deviation/sorting) at half-phi intervals above 63μm. Fine sediment (<63μm) was dried and weighed. Surface and bottom water samples were collected and measured for SSC, dissolved oxygen, temperature, and salinity to analyze changes in response to nourishment.