New nonresidential structures and nonresidential portions of mixed use structures, and substantial improvement (including repair of substantial damage) of existing nonresidential structures and nonresidential portions of mixed use structures shall comply with the applicable requirements of §§ 81-19 through 81-30 and the requirements of this section. See § 81-36 for requirements for horizontal additions.
(A) Elevation requirements. Elevated structures shall:
(1) Have the lowest floor (including basement) elevated to or above the flood protection elevation; or
(2) In areas of shallow flooding (Zone AO), have the lowest floor (including basement) elevated at least as high above the highest adjacent grade as the depth number specified in feet on the FIRM plus two feet, or at least four feet if a depth number is not specified; and
(3) Have enclosures below the lowest floor, if any, that comply with the requirements of § 81-34(C); or
(4) If proposed to be elevated on fill, meet the limitations on fill in § 81-34(B).
(B) Floodproofing requirements.
(1) Floodproofing of new nonresidential buildings:
(a) Is not allowed in nontidal waters of the state (Md. Code 17.04.11(B)(7)).
(b) Is not allowed in Coastal A Zones.
(2) Floodproofing for substantial improvement of nonresidential buildings:
(a) Is allowed in nontidal waters of the state.
(b) Is allowed in Coastal A Zones.
(3) If floodproofing is proposed, structures shall:
(a) Be designed to be dry floodproofed such that the building or structure is watertight with walls and floors substantially impermeable to the passage of water to the level of the flood protection elevation plus one foot; or
(b) If located in an area of shallow flooding (Zone AO), be dryfloodproofed at least as high above the highest adjacent grade as the depth number specified on the FIRM plus three feet, or at least five feet if a depth number is not specified; and
(c) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
(d) Have floodproofing measures that are designed taking into consideration the nature of flood-related hazards; frequency, depth and duration of flooding; rate of rise and fall of floodwater; soil characteristics; flood-borne debris; at least 12 hours of flood warning time from a credible source; and time necessary to implement any measures that require human intervention;
(e) Have at least one door above the applicable flood elevation that allows human ingress and egress during conditions of flooding;
(f) Have an operations and maintenance plan that is filed with local emergency management officials and that specifies the owner/occupant's responsibilities to monitor flood potential; the location of any shields, doors, closures, tools, or other goods that are required for implementation; maintenance of such goods; methods of installation; and periodic inspection; and
(g) Be certified by a licensed professional engineer or licensed architect, through execution of a floodproofing certificate that states that the design and methods of construction meet the requirements of this section. The floodproofing certificate shall be submitted with the construction drawings as required in § 81-15(A)(13).
(Ord. 02-2014, passed 4-21-2014)