Subtitle 3 – Development Regulations

If a proposed structure or substantial improvement is sited in 2 different subdistricts or in a subdistrict with 2 different flood elevations, the most restrictive regulation or higher flood elevation prevails.

For the purpose of applying appropriate requirements, structures are classified according to ASCE 24, Table 1-1 {“Classification of Structures for flood Resistant Design and Construction”}.

The approval of any development must conform with the requirements of the permit programs of:

Building, Fire, and Related Codes. The approval of any development must conform with all applicable requirements of the <cite data-path="|building-codes">Baltimore City Building, Fire, and Related Codes Article</cite>.

Where flood control and watershed management plans exist, all development must be consistent with those plans.

Every proposed structure must be placed on the lot so as to avoid location in the floodplain as much as possible.

Basements are not permitted in new structures and substantial improvement of existing structures (including repair of substantial damage).

Enclosures below the flood-protection elevation shall be:

Any horizontal expansion that increases the footprint and that is less than substantial must also have the lowest floor elevated to at least the flood-protection elevation.

In tidal and nontidal floodplains, any horizontal expansion that increases the footprint and that is less than substantial must also have the lowest floor elevated to at least the flood-protection elevation.

If the construction, reconstruction, or modification of any structure constitutes less than a substantial improvement:

All construction and improvements must be:

Unless the structure is dry floodproofed to the flood-protection elevation, materials used below that elevation must be resistant to floodwater damage, as specified in:

Tanks must be designed and installed as specified in ASCE 24, § 7.4.1 {“Tanks”}.

For installation in any structure located in any floodplain subdistrict, elevators must be designed and installed:

Adequate ground cover must be provided for soil stabilization within the Floodplain District.

Land contours must be designed and plant material chosen to direct surface runoff away from structures and not increase surface runoff onto neighboring properties.

Except as otherwise provided in subsection (b) of this section, electric, plumbing, and mechanical systems and their attendant components and equipment, including heaters, furnaces, generators, heat pumps, air conditioners, distribution panels, toilets, showers, sinks, duct work, and other permanent electrical, plumbing, or mechanical installations, are only permitted at or above the flood-protection elevation.

The placement of more than 600 cubic yards of fill per acre in the floodplain is prohibited except by variance.

Fill may be used only to the extent to which it does not adversely affect adjacent properties.

Fill material must be compacted in accordance with the standard proctor test method issued by the American Society for Testing and Materials (ASTM Standard D-698) to provide the necessary stability and resistance to erosion, scouring, or settling.

Fill slopes may be no steeper than 1 vertical to 2 horizontal, unless substantiating data justifying steeper slopes are submitted to and approved by the Department of Public Works.

Accessory structures shall be limited to no more than 300 square feet in total floor area.

Accessory structures:

New construction and substantial improvements of fully enclosed areas below the lowest floor or below the flood-protection elevation:

The State may have different, more stringent requirements set forth in <cite data-doc="Code of Maryland Regulations" data-path="|26.17.03">COMAR 26.17.03</cite> {“Construction on Nontidal Waters and Floodplains”}.

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

In the entire Floodplain District, the design, placement, and construction of all public and private utilities and facilities must meet:

All new storm drainage facilities within or leading to or from the Floodplain District must be adequately designed, floodproofed, and installed to:

In this section, “recreational vehicle” means a vehicle that is:

All recreational vehicles in the Floodplain District must be:

In this section, “temporary structure” a structure erected, installed, and used for a period not to exceed 180 days.

In addition to the requirements of <cite data-path="|7|§4-2">§ 4-2 {“Development Permits: Applications”} of this Division I</cite>, an application for the placement or erection of a temporary structure or for the temporary storage of any goods, materials, or equipment must specify the duration of the temporary use.

The temporary structure:

Storage in a temporary structure may not include any hazardous materials.

This section applies to any property owner requesting mapping changes.

A Letter of Map Change is an official FEMA determination, by letter, that amends or revises an effective Flood Insurance Rate Map or Flood Insurance Study.

A Letter of Map Amendment is an amendment based on technical data showing that a property was incorrectly included in a designated special flood hazard area. A LOMA amends the current effective Flood Insurance Rate Map and establishes that a specific property or structure is not located in a special flood hazard area.

A Letter of Map Revision is a revision based on technical data that may show changes to flood zones, flood elevations, floodplain and floodway delineations, and planimetric features. A Letter of Map Revision Based on Fill (LOMR-F), is a determination that a structure or parcel of land has been elevated by fill above the base flood elevation and is, therefore, no longer exposed to flooding associated with the base flood. In order to qualify for this determination, the fill must have been permitted and placed in accordance with the community’s floodplain management regulations.

A Conditional Letter of Map Revision is a formal review and comment as to whether a proposed flood protection project or other project comply with the minimum NFIP requirements for such projects with respect to delineation of special flood hazard areas. A Conditional Letter of Map Revision Based on Fill (CLOMR-F) is a determination that a parcel of land or proposed structure that will be elevated by fill would not be inundated by the base flood if fill is placed on the parcel as proposed or the structure is built as proposed. A CLOMR does not revise the effective Flood Insurance Rate Map or Flood Insurance Study; on submission and approval of certified as-built documentation, a Letter of Map Revision may be issued by FEMA, to revise the effective FIRM.

If a proposed development is contingent upon a map change, no permits will be issued for the development until the Letter of Map Revision (LOMR) has been issued by FEMA. The proposed development must be compliant with all pertinent requirements of Division I of <cite data-path="|7">Article 7</cite>.

the development complies with all otherwise applicable requirements of this Division I;

the effect of that development on flood heights is fully offset by accompanying stream modification; and

the development is approved by all appropriate local authorities, the State Water &amp; Science Administration, and the U.S. Army Corps of Engineers.

Any proposal to offset the effect of development in the Floodway by construction of stream modifications must be documented by an engineering report, prepared by a licensed professional engineer, that fully evaluates the effects of the construction and is submitted with the application for a building permit.

As the basis of analysis, the report must use the base flood and floodway data prepared by the Federal Emergency Management Agency.

Before a permit may be issued for any allowed development in the Floodway, the applicant must prepare and submit to the Planning Department an alternative analysis in accordance with this section.

The alternative analysis must demonstrate that:

The modification, alteration, repair, reconstruction, or improvement of any nonconforming structure amounting to less than a substantial improvement must be elevated or floodproofed to the greatest extent possible.

Uses or their adjuncts that are or become nuisances may not be permitted to continue.

The placement of any manufactured homes or buildings is prohibited.

The following may not be placed or caused to be placed in the Floodway:

In the Approximated Floodplain (Zones A and AO), the following additional regulations apply.

In the enforcement of this Division I, the Planning Department must obtain, review, and reasonably use any base-flood elevation and floodway data available from Federal, State, or other sources, such as the U.S. Army Corps of Engineers, the Soil Conservation Service, the State Water &amp; Science Administration, or any regional planning organization.

When the base-flood elevation is not known, the Planning Department, in consultation with the State Water &amp; Science Administration, must evaluate each site and establish an approximate base-flood elevation.

In the Coastal High Hazard Area (Zones V and VE):

No land below the level of the base flood may be developed unless the new construction or substantial improvement:

No new development in the Coastal High Hazard Area may be permitted unless the applicant demonstrates that:

An existing nonconforming structure located on land below the level of the base flood may not be expanded, vertically, horizontally, or otherwise, unless:

The placement of manufactured homes or buildings is strictly prohibited.

For all new construction and every substantially improved structure in the Coastal High Hazard Area, the developer must submit and the Floodplain Manager must maintain on file an elevation certificate that certifies the elevation of the bottom of the lowest horizontal structural member of the lowest floor.