Dredging
This guidance explains when dredging activities may need a marine licence from the Marine Management Organisation.
Applies to England and Northern Ireland
Overview
You may need a marine licence to carry out a dredging in English Waters or Northern Ireland offshore waters.
Dredging means using equipment to move material in the sea or on the seabed. It includes removing sediment completely or moving it from one place to another.
Some types of dredging are exempt from needing a licence. You can check if your activity is exempt before you apply.
Types of dredging
There are different types of dredging, depending on the purpose of the activity.
Clearance dredging
This is done to remove material that has built up around a structure or asset, for reasons other than navigation.
It usually needs a marine licence, but some activities may be eligible for self-service licensing.
Aggregate dredging
This is the removal of sand and gravel from the seabed for use in construction.
Aggregate dredging always requires a marine licence.
Categories of dredging
All dredging activities are classed as either capital or maintenance, depending on the depth and history of the area.
Capital dredging
This is dredging to a depth that either:
- has not been dredged before
- has not been dredged in the last 10 years
It’s usually done to:
- create or deepen a navigational channel or berth
- remove unsuitable material before construction
Maintenance dredging
Maintenance dredging involves removing recently built-up material, such as mud, sand or gravel, to keep areas like berths and channels at their intended depth.
This includes dredging for navigation, to make sure vessels can pass safely.
To count as maintenance dredging, the activity must meet both of these conditions:
- the dredging does not go deeper than the seabed level at any point in the last 10 years
- there is evidence that dredging has been carried out to that depth or deeper in the last 10 years
Whether maintenance dredging needs a licence depends on the volume of material and who is doing the work:
- less than 500 cubic metres – may be exempt from needing a marine licence
- 500 to 1500 cubic metres – may be suitable for accelerated licensing
- over 1500 cubic metres – may need a standard marine licence
Samples and analysis
You may need to provide a sediment sample analysis to support your dredging licence application, especially if it includes disposal of dredged material at sea.
Find out more about sediment sample analysis
Disposing of dredged material at sea
If your activity involves disposing of dredged material at sea, you will need a marine licence to cover the disposal as well as the dredging.
Where appropriate, both activities will be covered by a single licence.
You must give full details of the planned activity when you apply, including how and where you plan to dispose of material.
Find out more about disposing waste at sea
Maintenance dredge protocol
If you plan to carry out maintenance dredging in or near a marine protected area, such as a European site or Ramsar site, you must assess the environmental impact.
To support this assessment, you can use a baseline document. This should include all relevant information about past and current dredging. This helps show whether the activity is consistent with previous operations and whether it could have a significant effect, including alongside other nearby dredging.
Baseline documents are often used as part of a Maintenance Dredging Protocol (MDP). An MDP sets out how:
- maintenance dredging will be managed over time
- how environmental risks will be assessed and monitored
It can also make future assessments quicker and give confidence that dredging is being managed responsibly.
Water Framework Directive
If you apply for a marine licence, you may need to show how your dredging activity meets the requirements of the Water Framework Directive.
Find out more about information you may need to supply
Regional environmental assessments
In some regions, the marine aggregate industry has produced assessments that show the wider environmental context for dredging.
These are known as Marine Aggregate Regional Environmental Assessments (MAREAs). They are available for the Humber, Anglian, Thames and South Coast regions.
MAREAs:
- provide baseline environmental information for marine aggregate sites
- help assess the cumulative effects of current and future dredging activity
These assessments may help support your licence application if you’re planning to dredge in one of these regions.