Judgment_paragraph 31 · Brian Holohan and Others v An Bord Pleanála (C-461/17)

31More specifically, Article 6(3) of the Habitats Directive establishes an assessment procedure intended to ensure, by means of an ex ante examination, that a plan or project not directly connected with or necessary to the management of the site concerned but likely to have a significant effect on it is authorised only to the extent that it will not adversely affect the integrity of that site. That provision thus prescribes two stages. The first stage, envisaged in that provision’s first sentence, requires the Member States to carry out an appropriate assessment of the implications for a protected site of a plan or project when there is a likelihood that the plan or project will have a significant effect on that site. The second stage, which is envisaged in the second sentence of Article 6(3) of the Habitats Directive and which occurs following the aforesaid appropriate assessment, allows such a plan or project to be authorised on condition that it will not adversely affect the integrity of the site concerned (see, to that effect, judgment of 21 July 2016, Orleans and Others, C‑387/15 and C‑388/15, EU:C:2016:583, paragraphs 43 to 46 and the case-law cited).