1. Working Group on estuaries and coastal zones
Maintenance Dredging
GCF 13

2. Maintenance dredging
Dredging has been defined as the ‘’relocation of underwater sediments and soils for the construction and maintenance of waterways, dikes and transportation infrastructures and for reclamation and soil improvements’’
Capital dredging and aggregate dredging are not the target of this guidance concept form
Maintenance dredging is defined as ‘’the routine periodic removal of material in approach channels to port and harbour basins to maintain widths and depths in previously dredged areas to ensure the safe access for vessels’’
Maintenance dredging will modify the natural “engine” and its functions to give the ability to the local societies to fit the external factors with the maximum respect of the other components of the estuarine ecosystem

3. Maintenance dredging
Maintenance dredging is generally linked to societal choices made one or two centuries ago for maritime transport, protection against natural forces and/or agricultural development
This choices, with some others along the coastline or in the river basins, have modified the natural “engine”, sometime by accelerating natural evolution (multiplication by 2 or by 10 ?)
Any new choice will adjust the natural “engine” and have consequences on both socio-economical and environmental factors, however it would be unlikely to restore the preliminary situation. It would define an new balance with major impacts.

4. Maintenance dredging
Natural England highlights that the key issue in northern Europe over the next 100 years will be sea level rise, lack of accommodation space and the need for sufficient sediment to allow mudflats and salt marshes to keep pace with sea level rise.
The issues of today may generally be small, but we can have no confidence in that being the same in due course. Maintaining sediment budgets has to be a key target and regular assessments need to be undertaken.

5. Maintenance dredging
“Maintenance dredging” is a recurring activity which has to:
Maintain the existence of socio-economical features of the area and especially navigation
Help reaching the GES/GEP concerning physico-chemical and biological features
Help reaching FCS (a minima maintenance) concerning physical and biotic features of the habitats (species) of nature directives

6. Interpretation note
An interpretation note for estuaries was proposed by the EC in 2005 including a chapter on Ongoing (maintenance) activities with the following points:
there is no immediate reason to believe that existing activities associated with port maintenance, which had been carried out over a long period of time in an estuary prior to its proposal as a site of Community interest, cannot continue
However, the Court judgement made clear that such works would normally be considered to be plans or projects in terms of the Directive and an assessment of their potential impacts would therefore normally be required as a pre condition to the permitting process.

7. Interpretation note
This note was asking to integrate the appropriate assessment into the overall preparation of management plans. Sustainable Dredging Scheme may be part of such a management plan when it exists (e.g. not mandatory in UK)
The scheme (or management plan) should be underpinned by effective monitoring systems that enable, inter alia, assessment of the impact of potentially damaging operations that may affect the conservation objectives of the site and the GEP
The GCF 13 illustrates the Sustainable Maintenance Dredging Scheme with technical features and parameters to be considered in the appropriate assessment
The objective is to frame the authorisation process and not to replace it

8. Appropriate assessment
“Maintenance dredging” needs an appropriate assessment in relation to article 6 BHD. However, the periodicity of this assessment has to be defined and the potential impacts have to be monitored during the chosen period to give the ability to modify the global assessment
A Sustainable Maintenance Dredging Scheme, made on a voluntary basis, may solve this issue and help the national/regional authorities to support their decision concerning the renewal of authorisation to continue maintenance dredging
A Sustainable Maintenance Dredging Scheme will need an appropriate assessment

9. Scheme based on 3 existing ones
Physical setting understanding
Defra (Point 11), Delft (Point 1&2), Geode (Point 2)
Dredging operation
Defra (Points 1-8), Delft (Point 5), Geode (Point 1)
Monitoring
Defra (Point 12), Delft (Point 9), Geode (Point 4)
Impact on Nature
Defra (Point 11), Delft (Points 3 &4), Geode (Point 2)
Mitigation, rehabilitation, offset
Defra (Point 9), Delft (Point 6-8), Geode (Point 3)

10. Time frame Time frame is difficult to determine:
if it is every year it will not be considered as an improvement compared to the current situation
Member States have to report every six year on the conservation status and on the evaluation of the impact of the measures implemented
Longer period is considered as risky because of our prospective capabilities and climate change