Degrove Surveyors is currently supporting the U.S. Army Corps of Engineers and the Florida Department of Environmental Protection by completing Hydrographic/Topographic Surveys for beach monitoring in South Florida. Surveys are being performed at Pompano Beach and Bal Harbour Beach in Broward and Miami-Dade counties, respectively. Beach profile lines are being surveyed from the Coastal Construction Line, marked by construction control monuments, easterly 3,000 feet into the ocean. Field crews on the ground are utilizing RTK GPS to achieve topographic data on the beach, from the Coastal Construction control monuments to the maximum depth that can be waded.
The hydrographic data is being achieved through the use of two Degrove survey vessels: a 14-foot aluminum hull, inflatable pontoon boat with a 40hp outboard engine, and a 26-foot aluminum SeaArk with an enclosed cabin and twin 150hp outboards. The inflatable pontoon boat, having a very shallow draft, is being used to overlap the topographic data and survey the near-shore portions of the profile lines. The SeaArk is being used to survey the remaining length of the survey lines. Overlapping data is used as a quality control check to ensure a consistent surface is being achieved. Both vessels are equipped with RTK GPS for positioning and heading, electronic transducers and fathometers for soundings, and a motion reference unit (MRU) for determining heave corrections which are applied in the post-processing of the hydrographic data. Hydrographic cross lines are surveyed perpendicular to the profile lines at each site as an additional quality control check. In Miami-Dade County, an offshore borrow area is also being surveyed as part of the project.
The Florida Department of Environmental Protection (FDEP) works with the Army Corps of Engineers annually to complete these surveys to monitor beach erosion. This data is used for planning and to determine when beach renourishment will be completed.
Pictured above: Degrove’s 32-foot SeaArk at Pompano Beach in Broward County.
Degrove’s 14-foot inflatable pontoon boat which was used to achieve near-shore hydro data. Pompano Beach in background.
Processing laptop and fathometer as positioned in the 26-foot vessel.