If such nonconforming use is discontinued or terminated for a period of 12 months, any future use of the structure, land, or water shall conform to the provisions of this ordinance. When a nonconforming use or structure is damaged by fire, explosion, flood, the public enemy, or other calamity, to the extent of more than 50% of its current equalized assessed value, it shall not be restored except so as to comply with the use provisions of this ordinance.