The provisions of this article shall not apply to any activities or development for which final approval shall have been obtained from the local government or other authorities having jurisdiction over such activities or development, if such final approval was obtained prior to the date of approval of erosion hazard area regulations by the commissioner pursuant to section 34-0105 or 34-0106 of this article, or promulgation of such regulations pursuant to section 34-0107 of this article. As used in this section, the term "final approval" shall mean:

1. in the case of subdivision of land, conditional or preliminary approval of such plat pursuant to section two hundred seventy-six of the town law, section 7-728 of the village law or section thirty-two of the general city law; provided, however, that final plat approval is granted within six months of preliminary plat approval.

2. in the case of a site plan not involving the subdivision of land, approval by the appropriate body or office of a city, town or village of the site plan.

3. in those cases not covered by subdivision one or two of this section, the issuance of a building permit or other authorization for the commencement of the activities or development for which such permit or authorization was issued or in those local governments which do not require such permits or authorizations, the actual commencement of the activities or development.