Our Hydrographic Survey Unit has the capability to perform sidescan, multibeam, and single beam surveys using vessels from our Floating Plant Unit. The main duties of the Hydrographic Survey Unit include:
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Coastal engineering surveys
These are performed for a variety of purposes. In coastal areas, these surveys determine the condition of beach renourishment or support coastal engineering research studies. Surveys are also performed to study the effects of offshore protection structures (jetties, breakwaters, groins), harbor entrances, estuaries, and coastlines in areas of suspected accretion, erosion, or other material movement or transport. Surveys are also performed to develop, evaluate, and calibrate physical and numerical models used for planning and design of projects.
Dredging measurement and payment surveys
These are associated with contracted construction to measure the amount of excavated, deposited, and/or placed material in subsurface areas. These surveys also include investigative studies used for preparing contract bid documents and for directly monitoring and measuring subsequent contract performance, payment, and acceptance.
Project Condition Surveys
These determine the present condition of coastal and inland navigation channels, navigation locks, underwater features, river or flood control structures, or beach/bank erosion protection structures. These surveys are used to determine if project conditions have changed enough to warrant future construction or maintenance activities, if additional condition surveys are required at more frequent intervals, or if a greater survey coverage density is necessary.
Reservoir sedimentation surveys
These assess sedimentation and update area-capacity curves.
Underwater obstruction or condition surveys
These detect the existence and extent of obstructions to the safe use of waterways.
(USACE EM 1110-2-1003, 2002)