Assessment of the plans and projects in relation to NATURA 2000 sites is provision of the European Habitats Directive (92/43/EEC), in particular its article 6(3) and 6(4). The aim of these articles is to reveal negative impacts of plans and projects to coherence of NATURA 2000 network through appropriate assessment (AA) of their possible effects on integrity of the NATURA 2000 sites and in particular in regards to their effect on species and habitats that are sites target features. If impacts are detected such plans and projects have to be either avoided or amended, or if imperative reasons of overriding public interest are proved compensatory measures in favour of NATURA 2000 have to be taken to ensure overall coherence of the NATURA 2000 network.

The appropriate assessment can be best explained by some of its key characteristics:

• The assessment is concentrated only on impacts on the habitat types and species listed in the Annexes of Birds and Habitats Directive and not on all habitats and species which occur at the site.
• The assessment has to be performed for all intended plans and projects which might have an impact on NATURA 2000 habitats and species. Only plans and projects connected to the management of NATURA 2000 sites do not have to be assessed.
• All possible impacts should be analyzed: direct, indirect and cumulative impacts. The location of the projects is not decisive; even the projects that are outside of the site (i.e upstream on the river ) ) or some distance away may still have to be assessed as they may have impact on NATURA 2000 sites.
• The assessment has to have clear conclusion if the project has no significant effects to NATURA 2000 (and can be approved) or significant impacts remain and project has to be rejected. To remove significant negative effects mitigation measures can be defined or an alternative manner of implementation found. If that’s not possible the project is rejected.
• The results of the assessment can be overridden only through procedure of establishing imperative overriding reasons of public interest. In that case for reasons such as health, public safety, environmental benefits or other reasons including economical reasons, implementation of the project can be permitted but the lost site or portion of the site has to be compensated with added or restored area of identical characteristics.
• The precautionary principle states that if negative impacts cannot be excluded, because of insufficiency of the data or their inconclusive and imprecise nature, the concerns for conservation of NATURA2000 sites have to prevail.