Types of Dredging Projects
Dredging guarantees navigation and safety for harbors and environmental dredging reduces flooding, reestablishes riverbanks, eliminating contaminated sediments, and muck removal.
Performed on a regular basis to properly maintain a site that would otherwise get damaged by the sedimentation of sand or silt.
They have to be done so a new harbor can be developed.
Extreme weather conditions can lead to dangers that have to be removed immediately. Then the dredges help to ensure navigation and safety.
There are 2 main stages of dredging:
Sediment removal and Sediment disposal
The aim of disposal is to use the dredged material in an advantageous way. Apart from the environmental-related benefits, there are several industries that can profit out of it.
However, this doesn’t come without possible complications. The main concern is that the material might be contaminated.
In this case, the sediment has to be moved and disposed of according to regulations at special disposal facilities that prevent any damage.
Sometimes marinas and harbors contain contaminated materials as a result of various sources such as municipal discharges, runoffs or sewer overflows.
These contaminated materials are safe only because they are too deep under the seabed to be moved by regular navigation. Therefore maximum safety should be applied while dredging for these pollutants not to enter the environment.
They should never endanger humans or disrupt the ecosystem. Companies have to provide a dredging plan.
Effects of Storms
Powerful storms can negatively influence the waterbody and can turn dredging into an immediate necessity to allow navigation access. Along with the increased stream, there will also be more sediment.
Apart from additional sediment accumulation, storms can re-suspend sediments in the basins of marinas and harbors. It’s not out of the question for them to bring debris from other locations.
There are certain dredging depths that channels and harbors need to comply with. At the moment, a quite large part of the U.S. authorizations concerning dredging are the same ones as in the 19th century.
The permitted depth for dredging varies according to the traffic. On the high end, there are the channels that are navigated by freighters. Their dredged depth can go up to 30 feet deep.
Recreational boating harbors start at 9 feet. However, there are multipurpose harbors which have not only recreational, but also commercial purposes that can be as deep as 30 feet.
In their case you can frequently find various depths. They range from a deep entrance for commercial navigation to a gradually shallower one on the leisure side.
Sometimes it’s required to test the sediment and water quality for pollutants due to a historical background of previous activities or eventual discharges. It is important to know if dredging might have an impact or if there are conditions that might require the operations to be carried on using extra attention.
In order to apply for a dredging permit, it’s usually required to submit along a report about the material and the results of sediment testing. A survey can describe the reasons why the place needs dredging and show the depth of the area that should be dredged.