CR 707/Indian River Drive Shoreline Stabilization

The Indian River Keeper, an environmental interest group, was significantly opposed to a shoreline stabilizing and armoring project along the Indian River for CR 707/Indian River Drive in St. Lucie County, Florida. In response to the organization’s litigation against the Florida Department of Transportation and Federal Highway Administration, RS&H provided scientific assessments of the performance of the concrete block revetment and identified the direct and indirect impacts of the project to the area.

The shoreline stabilization and water quality study included: assessment of the environmental impact of the armored shoreline and its construction on the water quality of the Indian River Lagoon; analysis of the integrity of the articulated concrete armoring along the study area to determine, analyze, and compare the overall performance of the articulated concrete block revetment stabilizing system versus the non-stabilized shoreline along the project area; and evaluation of the direct impacts, if any, to the sea grasses and shoreline vegetation as result of the shoreline stabilization project.

RS&H adapted seagrass survey techniques and materials first developed by St. John’s River Water Management District and developed a sliding transect made of PVC piping to map the locations of seagrass beds for 1,000 square meters at each sampling location. The ten-meter by 2.5-meter sliding transect allowed for detailed underwater documentation in low visibility conditions. RS&H also used a surface-based air compressor called a “Brownie” that allowed divers unlimited diving time without the need to refill air tanks. The compressor eliminated the need to supply specialized diving equipment for divers when diving in deeper water.