Where can you find 8,000 limerock boulders within snorkeling distance from shore? Offshore from Dania Beach, Hollywood Beach, and Hallandale Beach in Broward County. Construction is complete for the county’s mitigation for the Segment III (Port Everglades to the south County line) Shore Protection Project. At a cost of $6 million, the boulders were placed at threenearshore sites to create 10.1 acres of artificial reef, compensating for 7.6 acres of future impacts by the beach project to nearshore hardbottoms. Placement was completed by Coastal Systems Development, Inc. (CSD) between June 2003 and September 2003.

Just prior to placement, CSD updated nearshore hard bottom locations, enabling the County to consolidate several sites into two large and one small mitigation areas. The close proximity of sensitive hard bottom substrate and shallow water depths of 15 feet (only 300 feet offshore) required that specialized moorings be designed for the crane barge.

Oceangoing tugs towed barges to transport 66,000 tons of boulders from quarries in Freeport, Grand Bahamas, to the project sites. The placement of the boulders was precisely controlled using a crane equipped with a DGPS positioning system, allowing a position to be obtained for each boulder. Crews worked around the clock during favorable weather conditions to complete the massive project in less than four months.

The county met their goal of having the mitigation constructed prior to beach construction (currently scheduled for June 2004), as preferred by regulatory and resource agencies as a way to maximize the value of the new habitat. The limerock resembles natural reef substrate and is already providing habitat for encrusting and boring organisms as well as fish life.

As an added benefit, stony corals over 15 cm in diameter will be relocated from the impact areas to the mitigation site to protect the organisms and to accelerate the productivity of the mitigation.

R. Harvey Sasso, P.E.-Principal, CSI
Stephen Higgins-Broward County, D.P.E.P