For the purposes of this section and sections 22a-361, 22a-361a, 22a-362, 22a-363b and 22a-363d to 22a-363f, inclusive: “Substantial maintenance” means rebuilding, reconstructing, or reestablishing to a preexisting condition and dimension any structure, fill, obstruction or encroachment; “routine maintenance” means replacement and repair of out-of-water structures including the surfaces of docks, piers, wharves and bridges, replacement or repair in any year of up to fifty per cent of all pilings approved in accordance with § 22a-361 and seasonal installation, reinstallation or repair of floating docks, provided that all locations, dimensions, elevations and materials shall remain the same as or equivalent to that approved in accordance with said section; “perimeter permit” means a permit issued in accordance with said section, establishing boundaries waterward of the coastal jurisdiction line within which recreational marinas layout of in-water slips, docks and moorings may be reconfigured; “work” means any activity, construction, or site preparation, erection of structures or placement of fill, including but not limited to grading, excavating, dredging or disposing of dredged material, depositing of soil, stones, sand, gravel, mud, aggregate or construction materials, filling, removing vegetation or other material, or other modification of a site within the tidal, coastal or navigable waters of the state waterward of the coastal jurisdiction line.