Beach Renourishment

Beach Renourishment Project

 

The beach along the oceanfront in Hillsboro Beach, Broward County provides shore protection for erosion caused by waves and other coastal processes.  Severe beach erosion is caused by winter storms and hurricanes. However, the constant erosion of our beaches is an undeniable reality.

 

What is Beach Erosion?

Wind, waves, and currents continually supply and remove sand from the beach. Erosion occurs when these forces remove more sand than they supply. The  natural movement of sand on and off the beach and along the coast is disrupted when inlets are created or enlarged, when development is allowed in the active dune, and by the placement of coastal structures like seawalls. Rising sea level and diminishing sand supply also contribute to beach erosion.

 

How Beach Nourishment Works

Beach nourishment involves pumping or trucking sand onto the beach to rebuild an eroding shoreline. Nourishment is the most natural beach restoration solution. In addition to the aesthetic enhancements, wider beaches enhance recreation, provide storm protection for roads and buildings, and potentially improve sea turtle nesting habitats.

Beach quality sand used for nourishment projects typically comes from offshore sand deposits, inlet shoals or is obtained from inland sources like sand mines.

 

Hillsboro/Deerfield Beach Renourishment Project

The Town of Hillsboro Beach, in cooperation with the City of Deerfield Beach, renourished their beaches in Broward County, Florida in 2011. The  HillsboroDeerfield Beach Renourishment Project (Project) involved placing approximately 340,000 cubic yards of beach compatable sand onto the beach along the southern 500 feet of the City of Deerfield Beach and the northern 5,750 feet of the Town of Hillsboro Beach.  As part of the Project, native dune vegetation was planted along 1,400 linear feet of dunes in Deerfield Beach.

 

The existing berm height was raised to +7.5 feet NAVD with a design profile consisting of a 1:15 foreshore slope transitioning to a 1:30 nearshore slope. The proposed Project area is residential with a mix of multi-family co-ops and condominiums. The Project design avoided impacts to nearshore hardbottom.

 

The renourishment event is in  accordance with Hillsboro Beach’s Long Range Beach Renourishment Plan and is consistent with the previously permitted renourishment event constructed in 1998. The renourished beach will provide a natural buffer from storms to the upland residential structures and will enhance the marine turtle nesting habitat and the recreational values of the shoreline within the Project vicinity. 

The renourishment of the Project area restored the highly valuable beach and dune system to this portion of Broward County. The beach is valuable, as it provides essential storm protection to the structures that directly front the beach in Hillsboro Beach.

 

Project Construction

Great Lakes Dredge and Dock Company, LLC (Great Lakes) mobilized the hydraulic cutterhead dredge Illinois to the offshore borrow area and beach fill placement commenced on March 12, 2011.  Fill placement was completed for the Project on April 11, 2011.  The sand for the restored beach was obtained from Borrow Area 1, a sandy section of the ocean floor located approximately 1,170 feet offshore of Deerfield Beach between Department of Environmental Protection survey monuments R-1 and R-6. Dune vegetation planting, consisting of 3,700 Beach Sunflower plants and 23,000 Sea Oat plants, was completed on May 1, 2011 along the existing dunes in Deerfield Beach.  The total construction cost for the Project was approximately $5.6M.

 

Project Biological Monitoring

A comprehensive biological monitoring program is required by the environmental permits issued for the Project by the following agencies:

  • U.S. Army Corps of Engineers
  • Florida Department of Environmental Protection
  • Broward County Department of Environmental Protection and Growth Management

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Ongoing biological monitoring is being conducted as follows:

  • Nearshore and borrow area adjacent hardbottom resources
  • Marine turtle tows
  • Escarpment Surveys during marine turtle nesting season

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Biologists are conducting the monitoring and processing reports through the various agencies for permit compliance.  The monitoring is required at established intervals over a five year period.

 

Project Physical Monitoring

The environmental agencies also require a comprehensive physical monitoring program to monitor the performance of the Project.  Monitoring efforts consist of the following:

  • Beach Profile Cross Section Surveys
  • Borrow Area Cross Section Surveys
  • Aerial Photography

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Annual engineering reports are prepared to summarize the data collected and to provide summaries of beach volume calculations and shoreline recession/accretion.  Physical monitoring is required for 5 years after Project construction.

 

Project Participants

Project Lead:

  • Town of Hillsboro Beach

 

Partner Cities:

 

Main Contractor:

Subcontractors:

Engineers: