For purposes of sections 25-200 to 25-210, inclusive, any structure or related facility including, but not limited to, a parking lot, septic system, pool or surfaced area, including, but not limited to, a paved, bricked, graveled walk or driveway, or a lawn or other landscaped area or a waste discharge authorized under chapter 446k, which exists within a designated river corridor on the date of designation, or agricultural land used for any agricultural purpose, as defined in section 1-1q, identified by the Commissioner of Agriculture in the inventory provided to the committee pursuant to section 25-204, including land reserved for crop rotation, may be maintained as such provided if, on or after such date of designation, any such structure, related facility, surfaced or landscaped area or agricultural land is degraded, damaged or destroyed, it may be replaced or restored without regard to the provisions of sections 25-200 to 25-210, inclusive, only if there is no significant change in its location, dimensions or elevations. Any permitted activities, authorized under title 22a, which exists within a designated river corridor on the date of designation may be reauthorized under said chapter without regard to the provisions of sections 25-200 to 25-210, inclusive. Land reserved for crop rotation shall not include “forest land” as defined in section 12-107b.