Marine Construction Activities
The activities associated with the field of Marine Construction are as vast and diverse as is the environment in which they are performed. Marine activities in general include establishment of shore erosion control measures and maintaining depths within the waterways. Specifically they include dredging, and the construction of bulkheads, revetments, jetties, groins, marsh, and piers.
The practice of shore erosion control has been dynamic. Improving and changing as technology and knowledge of resources advances. Wetland conservation in Maryland began in 1970. At that time the preferred method of shoreline protection was the creosoted timber bulkhead, followed shortly by CCA treated bulkheads and a variety of other components including concrete and vinyl. Regulators of that time focused on the location of the structure in the waterway. For example, construction closer to the shoreline was considered to be better. As such, encroachment into the waterways was minimized. Research out of the University of Georgia and other institutions showed that hardening shorelines with bulkheads was causing deleterious impacts to the marine environment by causing harm to marshes and shallow water habitat. Science showed that not only encroachment into the water ways was harmful to the aquatic ecosystem, the type of erosion control structure was also of great importance. Stone revetments then move to the forefront of the preferred methodology for shore protection. Stone provided good shore protection by dissipating and absorbing wave energy thereby minimizing impacts on shallow water, and its random and varied surfaces provided good aquatic habitat. The drawback to stone structures was the considerable encroachment it required into the waterway.
While stone was gaining popularity, scientists were experimenting with and developing procedures to grow marsh. Once established, marshes could provide good shoreline protection and excellent natural habitat. With the success of man-made marshes to control shore erosion, in 2008 the Maryland General Assemble pass a law require the establishment of marsh as the preferred method of shore protection. Only if it could be shown that these types of non-structural shore erosion control measures would be successful at a site would an alternative structural measure be allowed. Marshes are presently constructed throughout the Chesapeake and Atlantic Coastal Bays for shoreline protection and habitat restoration. Marshes are often protected with low profile stone sills and stone groins.
A detailed description of shore erosion control measures can be found in the MDE publication entitled “ A homeowners guide to *******”