Article IV: Requirements in Flood Hazard Areas (A Zones) That Are Not Coastal High Hazard Areas (V Zones) or Coastal A Zones

For proposed development that will encroach into a designated floodway, Section 131-12A(7) requires the applicant to submit an evaluation of alternatives to such encroachment, including different uses of the site or the portion of the site within the floodway, and minimization of such encroachment. This requirement does not apply to fences that do not block the flow of floodwaters or trap debris.

Proposed development in a designated floodway may be permitted only if:

The applicant has been issued a permit by MDE; and

The applicant has developed hydrologic and hydraulic engineering analyses and technical data prepared by a licensed professional engineer reflecting such changes, and the analyses, which shall be submitted to the Floodplain Administrator, demonstrate that the proposed activity will not result in any increase in the base flood elevation; or

If the analyses demonstrate that the proposed activities will result in an increase in the base flood elevation, the applicant has obtained a Conditional Letter of Map Revision and a Letter of Map Revision from FEMA upon completion of the project. Submittal requirements and fees shall be the responsibility of the applicant.

Development that includes the placement of fill in nontidal waters of the state. For proposed development that includes the placement of fill in nontidal waters of the state, other than development that is subject to Paragraph D, a hydraulically-equivalent volume of excavation is required. Such excavations shall be designed to drain freely.

Development in areas with base flood elevations but no designated floodways. For development in special flood hazard areas of nontidal waters of the state with base flood elevations but no designated floodways:

The applicant shall develop hydrologic and hydraulic engineering analyses and technical data reflecting the proposed activity and shall submit such technical data to the Floodplain Administrator as required in Section 131-12A(6). The analyses shall be prepared by a licensed professional engineer in a format required by FEMA for a Conditional Letter of Map Revision and a Letter of Map Revision upon completion of the project. Submittal requirements and fees shall be the responsibility of the applicant.

The proposed development may be permitted if the applicant has received a permit by MDE and if the analyses demonstrate that the cumulative effect of the proposed development, when combined with all other existing and potential flood hazard area encroachments, will not increase the base flood elevation more than 1.0 foot at any point.

Construction of roads, bridges, culverts, dams and in-stream ponds. Construction of roads, bridges, culverts, dams and in-stream ponds in nontidal waters of the state shall not be approved unless they comply with this section and the applicant has received a permit from MDE.

Alteration of a watercourse.

For any proposed development that involves alteration of a watercourse not subject to Paragraph C, unless waived by MDE, the applicant shall develop hydrologic and hydraulic engineering analyses and technical data reflecting such changes, including the floodway analysis required in Section 131-12A, and submit such technical data to the Floodplain Administrator and to FEMA. The analyses shall be prepared by a licensed professional engineer in a format required by MDE and by FEMA for a Conditional Letter of Map Revision and a Letter of Map Revision upon completion of the project. Submittal requirements and fees shall be the responsibility of the applicant.

Alteration of a watercourse may be permitted only upon submission, by the applicant, of the following:

A description of the extent to which the watercourse will be altered or relocated;

A certification by a licensed professional engineer that the flood-carrying capacity of the watercourse will not be diminished;

§ 131-31 Residential structures and residential portions of mixed use structures.

Evidence that adjacent communities, the U.S. Army Corps of Engineers and MDE have been notified of the proposal, and evidence that such notifications have been submitted to FEMA; and

(d)

Evidence that the applicant shall be responsible for providing the necessary maintenance for the altered or relocated portion of the watercourse so that the flood carrying capacity will not be diminished. The Floodplain Administrator may require the applicant to enter into an agreement with Harford County specifying the maintenance responsibilities; if an agreement is required, the permit shall be conditioned to require that the agreement be recorded on the deed of the property which shall be binding on future owners.

New residential structures and residential portions of mixed use structures, and substantial improvement (including repair of substantial damage) of existing residential structures, repetitive loss structures and residential portions of mixed use structures shall comply with the applicable requirements of Article III and this section. See Section 131-33 for requirements for horizontal additions.

Elevation requirements.

Lowest floors shall be elevated to or above the flood protection elevation.

In areas of shallow flooding (Zone AO), the lowest floor (including basement) shall be elevated at least as high above the highest adjacent grade as the depth number specified in feet on the FIRM plus 2 feet, or at least 4 feet if a depth number is not specified.

Enclosures below the lowest floor shall meet the requirements of Paragraph C.

Limitations on use of fill to elevate structures. Unless otherwise restricted by these regulations, especially by the limitations in Section 131-30A, Section 131-30B and Section 131-30C, fill placed for the purpose of raising the ground level to support a building or structure shall:

Consist of earthen soil or rock materials only.

Extend laterally from the building footprint to provide for adequate access as a function of use; the Floodplain Administrator may seek advice from the State Fire Marshal's office and/or the local fire services agency.

Comply with the requirements of the Building Code and be placed and compacted to provide for stability under conditions of rising and falling floodwaters and resistance to erosion, scour and settling.

(4)

Be sloped no steeper than 1 vertical to 2 horizontal, unless approved by the Floodplain Administrator.

(5)

Be protected from erosion associated with expected velocities during the occurrence of the base flood; unless approved by the Floodplain Administrator, fill slopes shall be protected by vegetation if the expected velocity is less than 5 feet per second, and by other means if the expected velocity is 5 feet per second or more.

(6)

Be designed with provisions for adequate drainage and no adverse effect on adjacent properties.

Enclosures below the lowest floor.

Enclosures below the lowest floor shall be used solely for parking of vehicles, building access, crawl/underfloor spaces or limited storage.

Enclosures below the lowest floor shall be constructed using flood damage-resistant materials.

Enclosures below the lowest floor shall be provided with flood openings which shall meet the following criteria: (NOTE: See NFIP Technical Bulletin #1, "Openings in Foundation Walls and walls of Enclosures.")

There shall be a minimum of 2 flood openings on different sides of each enclosed area; if a building has more than 1 enclosure below the lowest floor, each such enclosure shall have flood openings on exterior walls.

The total net area of all flood openings shall be at least 1 square inch for each square foot of enclosed area (non-engineered flood openings), or the flood openings shall be engineered flood openings that are designed and certified by a licensed professional engineer to automatically allow entry and exit of floodwaters; the certification requirement may be satisfied by an individual certification or an evaluation report issued by the ICC Evaluation Service, Inc.

§ 131-32 Nonresidential structures and nonresidential portions of mixed use structures.

The bottom of each flood opening shall be 1 foot or less above the higher of the interior floor or grade, or the exterior grade, immediately below the opening.

(d)

Any louvers, screens or other covers for the flood openings shall allow the automatic flow of floodwaters into and out of the enclosed area.

(e)

If installed in doors, flood openings that meet requirements of Paragraphs (a) through (d), are acceptable; however, doors without installed flood openings do not meet the requirements of this section.

New nonresidential structures and nonresidential portions of mixed use structures, and substantial improvement (including repair of substantial damage) of existing nonresidential structures, repetitive loss structures and nonresidential portions of mixed use structures shall comply with the applicable requirements of Article III and the requirements of this section. See Section 131-33 for requirements for horizontal additions.

Elevation requirements. Elevated structures shall:

Have the lowest floor (including basement) elevated to or above the flood protection elevation; or

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 2 feet, or at least 4 feet if a depth number is not specified; and

Have enclosures below the lowest floor, if any, that comply with the requirements of Section 131-31C; or

(4)

If proposed to be elevated on fill, meet the limitations on fill in Section 131-31B.

Floodproofing requirements.

Floodproofing of new nonresidential buildings:

Is not allowed in nontidal waters of the state [COMAR 26.17.04.11(B)(7)].

Is not allowed in Coastal A Zones.

Floodproofing for substantial improvement of nonresidential buildings:

Is allowed in nontidal waters of the state.

Is allowed in Coastal A Zones.

If floodproofing is proposed, structures shall:

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 1.0 foot, or

If located in an area of shallow flooding (Zone AO), be dry floodproofed at least as high above the highest adjacent grade as the depth number specified on the FIRM plus 3 feet, or at least 5 feet if a depth number is not specified; and

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 1 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 Section 131-12A(13).

§ 131-33 Horizontal additions.

A horizontal addition proposed for a building or structure shall comply with the applicable requirements of Article III and this section.

In nontidal waters of the state that are subject to the regulatory authority of MDE, all horizontal additions shall comply with the applicable requirements of Article III and this section.

If the addition combined with other proposed repairs, alterations or modifications of the base building constitutes substantial improvement, the base building and the addition shall comply with the applicable requirements of Article III and this section.

If the addition constitutes substantial improvement, the base building and the addition shall comply with all of the applicable requirements of Article III and this section.

[NOTE: See "Substantial Improvement/Substantial Damage Desk Reference" (FEMA P-758)]

§ 131-34 Accessory structures.

Accessory structures shall be limited to not more than 300 square feet in total floor area.

Accessory structures shall comply with the elevation requirements and other requirements of Section 131-31, the floodproofing requirements of Section 131-32B, or shall:

Be useable only for parking of vehicles or limited storage;

Be constructed with flood damage-resistant materials below the base flood elevation;