1. The appropriate assessment of the consequences of a plan or project for a Natura 2000 site means that (i) on the basis of the best available scientific knowledge (ii) all aspects of the plan or project concerned (iii) which, on their own (iv) or in combination with other plans or projects, (v) may jeopardise the site’s conservation objectives, must be identified.

2. Based on that appropriate assessment, the competent authority must have ascertained that the activity has no adverse effects on the natural features of the area concerned.

3. This is considered to have been ascertained if there is no reasonable scientific doubt that there are no harmful effects.

• The expected benefits must already have been established at the time of the appropriate assessment (the appropriate assessment must include definitive findings regarding the expected benefits and effectiveness of the measures or autonomous development).

• The expected benefits of measures will not have been established if, at the time of the appropriate assessment, the manner in which the benefits will be achieved has not yet been worked out, or the level of scientific knowledge does not allow those benefits to be identified or quantified with certainty.

• At the time of the appropriate assessment, it must be guaranteed that the measures and autonomous developments will produce results before the plan or project has negative consequences.

• A measure cannot be included in the appropriate assessment if the usefulness of that measure is the subject of scientific discussion.

• The fact that an appropriate assessment must contain definitive findings means that certainty as to whether certain benefits will manifest themselves must not be dependent on monitoring.

• The appropriate assessment must consider not only the likely positive effects of measures and autonomous developments but also any known or potential adverse effects.

• The measures must already have been implemented at the time of the appropriate assessment.

• NB: Monitoring may be an appropriate measure, but the fact that the implementation and impact of measures included in an appropriate assessment are monitored may not be deemed significant regarding whether the measures have already been established at the time of the appropriate assessment.

• The expected benefits do not count as having been established if, at the time of the appropriate assessment, the measures have not yet been fully implemented and those expected benefits depend on a development or response in nature, in the ecological system or in an animal species, such as the creation of new habitat types, habitats, or foraging areas or the enhancement of existing ones.
• This applies in full if a plan or project is subject to a condition that the resulting adverse impact on natural features may only take place after the measures or autonomous developments referred to above have been implemented and have had an effect.

• The developments must not be based on proposed policies;
• It must be certain that an observed downward trend will continue;
• The expected benefits of the developments must be identifiable with the required certainty and have been quantified at hexagon level; and
• It must be guaranteed that the allocation of deposition space derived from the developments does not take place before the reduction in deposition has manifested itself.

• NB: There is no relationship between an autonomous reduction and the emission-causing activity. There is therefore only scope for allocation of development space derived from the autonomous reduction if that reduction has definitely occurred at the time when the activities for which development space is allocated will start to cause emissions.

• It must be sufficiently certain that a measure will actually contribute to preventing an adverse impact on the natural features of the area concerned and guarantees that there is no reasonable doubt that the plan or project in question will not adversely affect the natural features of that area.

• The expected benefits do not count as having been established if, at the time of the appropriate assessment, the measures have not yet been fully implemented and those expected benefits depend on a development or response in nature, in the ecological system or in an animal species, such as the creation of new habitat types, habitats, or foraging areas or the enhancement of existing ones.
• This applies in full if a plan or project is subject to a condition that the resulting adverse effect on natural features may only take place after the measures or autonomous developments referred to above have been implemented and have had an effect.

• NB: Protective (technical) measures that are functionally linked to implementation of the plan or project – such as a standstill function or noise barrier – need not already have been fully implemented at the time of the appropriate assessment, but the expected benefits of such protective measures can only be included in the appropriate assessment if those measures have been established.

• A zoning plan which – individually or in combination with other plans or projects – may have significant effects for a Natura 2000 site can only be adopted if it has been ascertained, on the basis of an appropriate assessment, that the plan will not adversely affect the natural features of a Natura 2000 site (Sections 2.7(1) and 2.8(3) of the Wnb).
• A zoning plan that provides for a spatial development that – compared to the actual lawful situation under planning law, at the time of adoption of the plan – leads to an increase in nitrogen deposition on overloaded nitrogen-sensitive natural values in a Natura 2000 site is a plan that can have significant effects and that must be assessed appropriately (see the Council of State’s ruling of 20 December 2017, ECLI:NL:RVS:2017:3530).
• NB: Adoption of the zoning plan is not one of the decisions within the meaning of Section 2.7 of the Nature Conservation Decree [“Bnb”], so the PAS assessment framework does not apply. This does not alter the fact that various competent administrative bodies did not carry out an individual appropriate assessment for a zoning plan but referred regarding the nitrogen aspect to the appropriate assessment based on the PAS.

• The ruling may have effects for such zoning plans if the appeal procedure has not yet been completed and if, as regards the appropriate assessment, grounds for appeal have been advanced by the party entitled to invoke these provisions.

• Pursuant to Section 2.8(2) Wnb, it is not necessary to carry out an appropriate assessment for such zoning plans if the spatial development provided for in the plan has previously been the subject of an appropriate assessment and a new appropriate assessment cannot reasonably provide new information and insights into the significant effects of that plan.