During the environmental impact assessment phase of major infrastructure projects, changes will be considered significant if at least one of the following criteria is met: (i) A physical loss as defined in criterion D6C1; (ii) They cause a variation in absolute value of more than 10% of the average bottom shear stress relative to the reference situation; (iii) They cause a variation in absolute value of more than 10% of the duration of sedimentation or erosion with respect to the reference situation.

Pending the definition of a common methodology at OSPAR level, the scope of the following zones will be reported as a parameter that undergoes negative consequences of the permanent changes of hydrographic conditions due to the presence or exploitation of an infrastructure: (i) the areas that have undergone a physical loss within the context of criterion D6C1; (ii) the zones identified in criterion D7C1, whose habitat classification would change according to the prediction model for benthic habitats developed for the Celtic Sea and the broad North Sea as part of EMODNet habitat (Populus et al., 2017).

An impact demands consideration if one of the following conditions – related to the bottom stress on a 14 days spring tide/neap tide cycle as computed by validated mathematical models – is met: (i) there is an increase of more than 10% of the mean bottom shear stress (ii) the variation of the ratio between the duration of the bottom shear stress and the duration of the erosion is outside the “- 5%, + 5%” range

This consideration demanding impact (see target 29) remains within a distance equal to the root square of the surface occupied by this activity and taken from its inherent external limit.

All developments must comply with the existing regulatory regime (e.g. EIA, SEA, and Habitats Directives) and regulatory assessments must be undertaken in such a way that takes into consideration any potential impacts arising from permanent changes in hydrographical conditions, including cumulative effects, at the most appropriate spatial scales following the guidance prepared to this end.