The purpose of this appendix is to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific flood hazard areas through the establishment of comprehensive regulations for management of flood hazard areas designed to:
- Prevent unnecessary disruption of commerce, access and public service during times of flooding;
- Manage the alteration of natural flood plains, stream channels and shorelines;
- Manage filling, grading, dredging and other development which may increase flood damage or erosion potential;
- Prevent or regulate the construction of flood barriers which will divert floodwaters or which can increase flood hazards; and
- Contribute to improved construction techniques in the flood plain.
COASTAL DUNE. Any natural hill, mound or ridge of sediment landward of a coastal beach deposited by wind action or storm overwash. Coastal dune also means sediment deposited by artificial means and serving the purpose of storm damage prevention or flood control. For purposes of this appendix, a coastal dune is one that has been determined to be significant to the interests of flood control and/or storm damage prevention as defined in the Wetlands Protection Act, M.G.L. c. 131, § 40.
MANUFACTURED HOME. A structure that is transportable in one or more sections, built on a permanent chassis, designed for use with or without a permanent foundation when attached to the required utilities, and constructed to the Federal Mobile Home Construction and Safety Standards and rules and regulations promulgated by the U.S. Department of Housing and Urban Development. The term also includes mobile homes, park trailers, travel trailers and similar transportable structures that are placed on a site for 180 consecutive days or longer.
RECREATIONAL VEHICLE. A vehicle that is built on a single chassis, 400 square feet (37.16 m2) or less when measured at the largest horizontal projection, designed to be self-propelled or permanently towable by a light-duty truck, and designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel or seasonal use. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect-type utilities and security devices and has no permanently attached additions.
Construction documents shall indicate proposed details of floor,wall,foundation support components, loading computations, and other essential technical data used to meet the requirements of this appendix.
- All space below the base flood elevation plus one foot shall be constructed with walls and floors that are substantially impermeable to the passage of water.
- All structural components subject to hydrostatic and hydrodynamic loads and stresses during the occurrence of flooding to the base flood elevation shall be capable of resisting such forces, including the effects of buoyancy.
- All openings below the base flood elevation plus one foot shall be provided with water-tight closures and shall have adequate structural capacity to support all flood loads acting upon the closure surfaces.
- All floor and wall penetrations for plumbing, mechanical and electrical systems shall be made water tight to prevent floodwater seepage through spaces between the penetration and wall construction materials. Sanitary sewer and storm drainage systems that have openings below the base flood elevation plus one foot shall be provided with shutoff valves or closure devices to prevent backwater flow during conditions of flooding.
- Mat or raft foundations, piling, pile caps, bracing, grade beams and columns which provide structural support for the building.
- Entrances and exits used for required means of egress.
- Incidental storage of portable or mobile items readily moved in the event of a storm.
- Walls and partitions are permitted to enclose all or part of the space below the elevated floor provided that such walls and partitions are not part of the structural support of the building and are constructed with insect screening, open wood lattice, or non-supportingwalls designed to break awayor collapse without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system due to the effect of wind and water loads as specified in section 16.00 acting simultaneously.
In flood hazard areas, tank inlets, fill openings, outlets and vents shall be:
- At or above the design flood elevation or fitted with covers designed to prevent the inflow of floodwater or outflow of the contents of the tanks during conditions of the design flood.
- Anchored to prevent lateral movement resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, during conditions of the design flood.
Fully enclosed areas below the design flood elevation shall be at or above grade on all sides and conform to the following:
- In flood hazard areas not subject to high-velocity wave action, enclosed areas shall have flood openings to allow for the automatic inflow and outflow of floodwaters.
- In flood hazard areas subject to high-velocity wave action, enclosed areas shall have walls below the design flood elevation that are designed to break away or collapse from a water load less than that which would occur during the design flood, without causing collapse, displacement or other structural damage to the building or structure.
|ASCE 24—05||Flood Resistance Design and Construction||G103.1, G401.3, G401.4|
|HUD 24 CFR Part 3280 (1994)||Manufactured Home Construction and Safety Standards||G201|
|IBC—09||International Building Code||G102.2|
|NFPA 70—08||National Electrical Code||G1001.6|