Calvert County, MD Article VII Specific Requirements

§ 46-31 Applicability.

In addition to the requirements outlined in Articles IV and V, the following specific requirements must be applied.

§ 46-32 Placement of buildings and materials.

In general, buildings and accessory structures should be located entirely out of the floodplain. All structures permitted in the floodplain shall be oriented so as to offer the least resistance to the flow of floodwaters. Materials which are buoyant, flammable, explosive, hazardous to health, or which at times of flooding may be injurious to human, animal or plant life, shall not be stored below the flood protection elevation.

§ 46-33 Enclosures below lowest floor.

A. Buildings which have been elevated and have fully enclosed areas below the flood protection elevation, as well as garages and accessory structures which are not elevated (§ 46-37), shall be constructed with water-equalizing vents which meet or exceed the following standards:

(1) A minimum of two openings on different walls having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding;

(2) The bottom of all openings shall be no higher than one foot above grade; and

(3) Openings may be equipped with screens, louvers, valves or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters to equalize hydrostatic forces on the walls.

B. Fully enclosed areas below the flood protection elevation shall be used solely for parking of vehicles, access to the building or storage. If such areas are enclosed, a nonconversion agreement as described in § 46-10 must be signed by the applicant.

C. In coastal high-hazard areas, enclosures below the flood protection elevation shall comply with the provisions of § 46-26 of this chapter.

§ 46-34 Manufactured homes and manufactured home parks. [1]

A. New manufactured homes and manufactured home parks are prohibited in the coastal high-hazard area. In other floodplain zones, all new, replacement or substantially improved manufactured homes, whether in a manufactured home park or not, shall comply with § 46-21 of this chapter.

B. Methods of anchoring shall include use of over-the-top and frame ties to ground anchors. Pilings or columns shall be used to maintain storage capacity of the floodplain. Concrete block support pilings must be reinforced by placing reinforcing bars inside and extending them into the footing, filling the hollows with cement and using mortar to cement the blocks together. FEMA Publication 85, Manufactured Home Installation in Flood Hazard Areas, should be consulted for specific recommendations.

C. Manufactured homes repaired or replaced because of substantial damage due to flooding or other causes are considered to be new structures and must fully comply with § 46-21.

D. Owners of manufactured home parks or subdivisions that are partially or fully within the floodplain must file an evacuation plan with the local emergency management agency. In nontidal floodplains, a flood-free access road shall be provided in all new manufactured home parks and subdivisions.

[1] Editor's Note: See also Ch. 71, Manufactured (Mobile) Home Rental Communities.

§ 46-35 Anchoring.

All structures shall be firmly anchored in accordance with acceptable engineering practices to prevent flotation, collapse and lateral movement during flooding. All air ducts, large pipes and storage tanks located below the flood protection elevation shall be firmly anchored to resist flotation.

§ 46-36 Utilities.

A. Electric. All electric utilities to the building side of the meter, both interior and exterior to the building, are regulated by this chapter. Distribution panel boxes must be at least two feet above the flood protection elevation. All outlets and electrical installations, such as heat pumps, air conditioners, water heaters, furnaces, generators, distribution systems, must be installed at or above the flood protection elevation.

B. Plumbing. Toilets, sinks, showers, water heaters, pressure tanks, furnaces and other permanent plumbing installations must be installed at or above the flood protection elevation.

C. Gas. Gas meters, distribution lines and gas appliances must be installed at or above the flood protection elevation.

D. Water supply and sanitary facilities. Water supply distribution and sanitary disposal collection systems must be designed to minimize or eliminate the infiltration of floodwaters into the systems or discharges from the systems into floodwaters and shall be located and constructed so as to minimize or eliminate flood damage. On-site sewage disposal systems shall meet these same standards.

§ 46-37 Accessory structures and garages.

A. Where feasible, accessory structures and garages should be located out of the floodplain or elevated to or above the flood protection elevation. When these measures are not feasible the following apply:

(1) The floor of the structure must be at or above grade;

(2) The structure must be located, oriented and constructed so as to minimize flood damage; and

(3) The structure must be firmly anchored to prevent flotation.

B. Attached garages. A garage attached to the main structure shall be elevated to the greatest extent possible, but may be permitted as an exemption to the strict elevation requirement if it is used solely for parking of vehicles, storage, or building access and is no more than 600 square feet in area. Attached garages must meet the venting requirements of § 46-33, have all interior walls, ceilings and floors below the flood protection elevation unfinished, and have no machinery or electric devices or appliances located below the flood protection elevation. A nonconversion agreement as described in § 46-10 must be signed by the property owner stating that the garage may never be used for human habitation without first becoming fully compliant with this chapter.

C. Detached garages and accessory structures. An accessory structure or detached garage may be permitted as an exemption to the elevation requirement if it is less than 300 square feet, used solely for parking of vehicles and limited storage, meets the venting requirements of § 46-33, has all interior wall, ceiling and floor elements below the flood protection elevation unfinished, and has no machinery, electric devices or appliances located below the flood protection elevation. A nonconversion agreement must be signed by the property owner.

D. An accessory structure or a detached garage between 300 square feet and 600 square feet may be permitted below the flood protection elevation only by a conditioned permit described in § 46-10.

E. An accessory structure or garage larger than 600 square feet in area must be elevated properly or be able to meet all applicable requirements under the variance procedure in § 46-40 of this chapter.

§ 46-38 Recreational vehicles.

A. Recreational vehicles located within the floodplain may be exempted from the elevation and anchoring requirements provided they are:

(1) Located on the site less than 180 consecutive days per year;

(2) Fully licensed and ready for highway use; and

(3) Properly permitted.

B. A recreational vehicle is ready for highway use if it is on its wheels and jacking system, is attached to the site only by quick disconnect type utilities and securing devices and has no permanently attached additions. If it cannot meet all of these criteria, the recreational vehicle must be considered a manufactured home and is subject to the elevation and construction standards of this chapter.

§ 46-39 Fill.

A. Fill is discouraged because storage capacity is removed from floodplains. Other methods of elevating structures should be considered first, and fill used only if other methods are not feasible. Fill may not be used for structural support in coastal high-hazard areas. Fill may not be placed in tidal or nontidal wetlands without the required state and federal permits.

B. Fill must consist of soil and rock materials only. Dredged material may be used as fill only upon certification of suitability by a registered professional geotechnical engineer. Landfills, rubble fills, dumps and sanitary fills are not permitted in the floodplain.

C. Fill used to support structures must be compacted to 95% of the maximum density obtainable by the Standard Proctor Test (ASTM Standard D-698), and its suitability to support structures certified by a registered professional engineer. Fill slopes shall be no greater than two horizontal to one vertical. Flatter slopes may be required where velocities may result in erosion.

D. The use of fill shall not increase flooding or cause drainage problems on neighboring properties.