Hillsboro Beach Summary & Conclusions

• The approximately 401,000 cy of sand remaining within the project boundaries above the depth of closure (-15 feet NGVD) for the fourth monitoring period is greater than the 220,000 cy design value. Therefore, the project area contains adequate volumes within the beach system to provide the required storm protection.  At the current erosion rate of approximately -37,000 cy/year and/or historical (Coastal Systems, 1997) erosion rate of approximately -11,000 cy/year, it is expected that the design volume should not be compromised prior to reaching the design life of 8 to 10 years pending major storm activity.
• While the volume of sand remaining within the project limits is performing per design, shoreline recession rates have exceeded design expectations.  Review of the profiles and design templates show that the profiles, particularly along the northern (R-7) and southern (R-11) portions of the project have recessed into the minimum design template above approximately -4 feet NGVD.
• The formation of the relatively large or significant offshore bar is likely due to the heavy storm activity of 1999 and further by Hurricane Michelle in 2001, which caused cross-shore movement of sand into shallow, flattened profiles that are typical of post hurricane conditions.