[HISTORY: Adopted by the Township Committee of the Township of Mantua 9-28-1982 by Ord. No. 9-1982 (Ch. 79 of the 1978 Code); amended in its entirety 8-1-2016 by Ord. No. O-9-2016. Subsequent amendments noted where applicable.]
The Legislature of the State of New Jersey has, in N.J.S.A. 40:48-1 et seq., delegated the responsibility to local governmental units to adopt regulations designed to promote public health, safety, and general welfare of its citizenry. Therefore, Mantua Township of the Township of Mantua of Gloucester County, New Jersey, does ordain as follows.
The flood hazard areas of the Township of Mantua are subject to periodic inundation, which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety, and general welfare.
These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazard which increase flood heights and velocities and, when inadequately anchored, cause damage in other areas. Uses that are inadequately floodproofed, elevated or otherwise protected from flood damage also contribute to the flood loss.
It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:
Protect human life and health;
Minimize expenditure of public money for costly flood control projects;
Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
Minimize prolonged business interruptions;
Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, bridges located in areas of special flood hazard;
Help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas;
Ensure that potential buyers are notified that property is in an area of special flood hazard; and
Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.
In order to accomplish its purposes, this chapter includes methods and provisions for:
Restricting or prohibiting uses which are dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;
Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel floodwaters;
Controlling filling, grading, dredging, and other development which may increase flood damage; and
Preventing or regulating the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards in other areas.
Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meanings they have in common usage and to give this chapter its most reasonable application.
As used in this chapter, the following terms shall have the meanings indicated:
- AH ZONE
- Areas subject to inundation by one-percent-annual-chance shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base flood elevations (BFEs) derived from detailed hydraulic analyses are shown in this zone.
- AO ZONE
- Areas subject to inundation by one-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet.
- A request for a review of the Construction Official's interpretation of any provision of this chapter or a request for a variance.
- AREA OF SPECIAL FLOOD HAZARD
- Land in the floodplain within a community subject to a one-percent or greater chance of flooding in any given year. It is shown on the FIRM as Zone V, VE, V1-30, A, AO, A1 A30, AE, A99, or AH.
- AREAS OF SHALLOW FLOODING
- A designated AO, AH, or VO Zone on a community's Digital Flood Insurance Rate Map (DFIRM) with a one-percent annual or greater chance of flooding to an average depth of one foot to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
- BASE FLOOD
- The flood having a one-percent chance of being equaled or exceeded in any given year.
- BASE FLOOD ELEVATION (BFE)
- The flood elevation shown on a published Flood Insurance Study (FIS) including the Flood Insurance Rate Map (FIRM). For Zones AE, AH, AO, and A1-30, the elevation represents the water surface elevation resulting from a flood that has a one-percent or greater chance of being equaled or exceeded in any given year. For Zones VE and V1-30, the elevation represents the stillwater elevation (SWEL) plus wave effect (BFE = SWEL + wave effect) resulting from a flood that has a one-percent or greater chance of being equaled or exceeded in any given year.
- Any area of the building having its floor subgrade (below ground level) on all sides.
- BREAKAWAY WALL
- A wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces without causing damage to the elevated portion of the building or supporting foundation system.
- COASTAL A ZONE
- The portion of the special flood hazard area (SFHA) starting from a Velocity (V) Zone and extending up to the landward limit of the moderate wave action delineation. Where no V Zone is mapped, the Coastal A Zone is the portion between the open coast and the landward limit of the moderate wave action delineation. Coastal A Zones may be subject to wave effects, velocity flows, erosion, scour, or a combination of these forces. Construction and development in Coastal A Zones is to be regulated the same as V Zones/coastal high hazard areas.
- COASTAL HIGH HAZARD AREA
- An area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or seismic sources.
- Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials located within the area of special flood hazard.
- DIGITAL FLOOD INSURANCE RATE MAP (DFIRM)
- The official map on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.
- (1) A nonbasement building:
- (a) Built, in the case of a building in an area of special flood hazard, to have the top of the elevated floor or, in the case of a building in a Coastal A Zone, to have the bottom of the lowest horizontal structural member of the elevated floor elevated above the base flood elevation plus freeboard by means of piling, columns (posts and piers), or shear walls parallel to the flow of the water; and
- (b) Adequately anchored so as not to impair the structural integrity of the building during a flood up to the magnitude of the base flood.
- (2) In an area of special flood hazard, "elevated building" also includes a building elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of floodwaters. In areas of Coastal A Zones, "elevated buildings" also includes a building otherwise meeting the definition of "elevated building," even though the lower area is enclosed by means of breakaway walls.
- The process of the gradual wearing away of land masses.
- EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
- A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.
- FLOOD INSURANCE RATE MAP (FIRM)
- The official map on which the Federal Insurance Administration has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.
- FLOOD INSURANCE STUDY (FIS)
- The official report in which the Federal Insurance Administration has provided flood profiles, as well as the Flood Insurance Rate Map(s) and the water surface elevation of the base flood.
- FLOOD or FLOODING
- A general and temporary condition of partial or complete inundation of normally dry land areas from:
- FLOODPLAIN MANAGEMENT REGULATIONS
- Zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as a floodplain ordinance, grading ordinance and erosion control ordinance) and other applications of police power. The term describes such state or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction.
- Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
- The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than 0.2 foot.
- A factor of safety usually expressed in feet above a flood level for purposes of floodplain management. Freeboard tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed.
- HIGHEST ADJACENT GRADE
- The highest natural elevation of the ground surface prior to construction next to the proposed or existing walls of a structure.
- HISTORIC STRUCTURE
- Any structure that is:
- (1) Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
- (2) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;
- (3) Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or
- (4) Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
- LIMIT OF MODERATE WAVE ACTION (LiMWA)
- Inland limit of the area affected by waves greater than 1.5 feet during the base flood. Base flood conditions between the V Zone and the LiMWA will be similar to, but less severe than, those in the V Zone.
- LOWEST FLOOR
- The lowest floor of the lowest enclosed area (including basement). An unfinished or flood-resistant enclosure, useable solely for the parking of vehicles, building access or storage in an area other than a basement is not considered a building's lowest floor, provided that such enclosure is not built so to render the structure in violation of other applicable nonelevation design requirements of 44 CFR 60.3.
- MANUFACTURED HOME
- A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term "manufactured home" does not include a recreational vehicle.
- MANUFACTURED HOME PARK or MANUFACTURED HOME SUBDIVISION
- A parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
- NEW CONSTRUCTION
- Structures for which the start of construction commenced on or after the effective date of a floodplain regulation adopted by a community and includes any subsequent improvements to such structures.
- NEW MANUFACTURED HOME PARK OR SUBDIVISION
- A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of the floodplain management regulations adopted by the municipality.
- RECREATIONAL VEHICLE
- A vehicle which is:
- (1) Built on a single chassis;
- (2) Four hundred square feet or less when measured at the longest horizontal projections;
- (3) Designed to be self-propelled or permanently towable by a light-duty truck; and
- (4) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
- SAND DUNES
- Naturally occurring or man-made accumulations of sand in ridges or mounds landward of the beach.
- START OF CONSTRUCTION
- For other than new construction or substantial improvements under the Coastal Barrier Resources Act (P.L. No. 97-348), includes substantial improvements and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within 180 days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site such as the pouring of a slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation, or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling, nor does it include the installation of streets and/or walkways, nor does it include excavation for a basement, footings or piers, or foundations or the erection of temporary forms, nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.
- A walled and roofed building, a manufactured home, or a gas or liquid storage tank that is principally aboveground.
- SUBSTANTIAL DAMAGE
- Damage of any origin sustained by a structure whereby the cost of restoring the structure to its condition before damage would equal or exceed 50% of the market value of the structure before the damage occurred.
- SUBSTANTIAL IMPROVEMENT
- Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50% of the market value of the structure before the start of construction of the improvement. This term includes structures which have incurred substantial damage, regardless of the actual repair work performed. The term does not, however, include either:
- (1) Any project for improvement of a structure to correct existing violations of state or local health, sanitary or safety code specifications which have been identified by the local code enforcement officer and which are the minimum necessary to assure safe living conditions; or
- (2) Any alteration of an historic structure, provided that the alteration will not preclude the structure's continued designation as an historic structure.
- A grant of relief from the requirements of this chapter that permits construction in a manner that would otherwise be prohibited by this chapter.
- The failure of a structure or other development to be fully compliant with this chapter. A new or substantially improved structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in 44 CFR 60.3(b)(5), (c)(4), (c)(10), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided.
Editor's Note: See 16 U.S.C. § 3501 et seq.
This chapter shall apply to all areas of special flood hazard within the jurisdiction of the Township of Mantua, Gloucester County, New Jersey.
The areas of special flood hazard for the Township of Mantua, Community No. 340207, are identified and defined on the following documents prepared by the Federal Emergency Management Agency:
A scientific and engineering report, "Flood Insurance Study, Gloucester County, New Jersey (All Jurisdictions)," dated August 17, 2016.
Flood Insurance Rate Map for Gloucester County, New Jersey (All Jurisdictions) as shown on Index and Panel Numbers 34015C0087F, 34015C0088E, 34015C0089E, 34015C0091F, 34015C0092F; 34015C0093E, 34015C0094E, 34015C0113E, 34015C0177E, 34015C0181E, 34015C0182E, 34015C0184E, 34015C0201E, whose effective date is August 17, 2016.
The above documents are hereby adopted and declared to be a part of this chapter. The Flood Insurance Study and maps are on file at 401 Main Street, Mantua, New Jersey 08051.
No structure or land shall hereafter be constructed relocated, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the provisions of this chapter by failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a misdemeanor. Any person who violates this chapter or fails to comply with any of its requirements shall, upon conviction thereof, be fined not more than $2,000 or imprisoned for not more than 90 days, or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the Township of Mantua from taking such other lawful action as is necessary to prevent or remedy any violation.
Each day that a violation exists, occurs or continues shall constitute a separate offense for the purpose of imposing penalties referred to above.
This code is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and other ordinances, codes, easements covenants, or deed restrictions conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
In the interpretation and application of this chapter, all provisions shall be:
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man-made or natural causes. This chapter does not imply that land outside the areas of special flood hazard or uses permitted within such areas will be free from flooding or flood damages.
This code shall not create liability on the part of the Township of Mantua, any officer or employee thereof or the Federal Insurance Administration for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.
A development permit shall be obtained before construction or development begins, including placement of manufactured homes, within any area of special flood hazard established in § 188-7. Application for a development permit shall be made on forms furnished by the Construction Official and may include, but not be limited to, plans, in duplicate, drawn to scale showing the nature, location; dimensions, and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required:
Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;
Elevation in relation to mean sea level to which any structure has been floodproofed;
Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in § 188-17B; and
Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
The Construction Official is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.
Duties of the Construction Official shall include, but not be limited to:
Review all development permits to determine that the permit requirements of this chapter have been satisfied.
Review all development permits to determine that all necessary permits have been obtained from those federal, state or local governmental agencies from which prior approval is required.
Review all development permits to determine if the proposed development is located in the floodway, assure that the encroachment provisions of § 188-17D(1) are met.
Review all development permits in the Coastal A Zone area of the area of special flood hazard to determine if the proposed development alters the terrain or sand dunes so as to increase potential flood damage.
Review plans for walls to be used to enclose space below the base flood level in accordance with § 188-176(4).
Use of other base flood and floodway data. When base flood elevation and floodway data has not been provided in accordance with § 188-7, Basis for establishing areas of special flood hazard, the Construction Official shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer § 188-17A, Specific standards, Residential construction, and § 188-17B, Specific standards, Nonresidential construction.
Information to be obtained and maintained.
Obtain and record the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all new or substantially improved structures, and whether or not the structure contains a basement.
For all new or substantially improved floodproofed structures:
Verify and record the actual elevation (in relation to mean sea level).
Maintain for public inspection all records pertaining to the provisions of this code.
Alteration of watercourses.
Notify adjacent communities and the New Jersey Department of Environmental Protection, Dam Safety and Flood Control Section, and the Land Use Regulation Program prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration.
Require that maintenance is provided within the altered or relocated portion of said watercourse so the flood-carrying capacity is not diminished.
Substantial damage review.
After an event resulting in building damages, assess the damage to structures due to flood and nonflood causes.
Record and maintain the flood and nonflood damage of substantial damage structures and provide a letter of substantial damage determination to the owner and the New Jersey Department of Environmental Protection, Dam Safety and Flood Control Section.
Interpretation of FIRM boundaries. Make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in § 188-15.
Appeals to the Zoning Board of Adjustment.
The Zoning Board of Adjustment, established by the Township of Mantua, shall hear and decide appeals and requests for variances from the requirements of this code.
The Zoning Board of Adjustment shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Construction Official in the enforcement or administration of this code.
Those aggrieved by the decision of the Zoning Board of Adjustment, or any taxpayer, may appeal such decision to the Superior Court of New Jersey, as provided by law.
In passing upon such applications, the Zoning Board of Adjustment shall consider all technical evaluations, all relevant factors, standards specified in other sections of this code, and:
The danger that materials may be swept onto other lands to the injury of others;
The danger to life and property due to flooding or erosion damage;
The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;
The importance of the services provided by the proposed facility to the community;
The necessity to the facility of a waterfront location, where applicable;
The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
The compatibility of the proposed use with existing and anticipated development;
The relationship of the proposed use to the comprehensive plan and floodplain management program of that area;
The safety of access to the property in times of flood for ordinary and emergency vehicles;
The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters and the effects of wave action, if applicable, expected at the site; and
The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water systems, and streets and bridges.
Upon consideration of the factors of § 188-15A(4) and the purposes of this code, the Zoning Board of Adjustment may attach such conditions to the granting of variances as it deems necessary to further the purposes of this code.
The Construction Official shall maintain the records of all appeal actions, including technical information, and report any variances to the Federal Insurance Administration upon request.
Conditions for variances.
Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of 1/2 acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items in § 188-15A(4)(a) through (k) have been fully considered. As the lot size increases beyond the 1/2 acre, the technical justification required for issuing the variance increases.
Variances may be issued for the repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as an historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.
Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.
Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
Variances shall only be issued upon:
A showing of good and sufficient cause;
A determination that failure to grant the variance would result in exceptional hardship to the applicant; and
A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public as identified in § 188-15A(4), or conflict with existing local laws or ordinances.
Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.
In all areas of special flood hazard, compliance with the applicable requirements of the Uniform Construction Code (N.J.A.C. 5:23) and the following standards, whichever is more restrictive, is required:
All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
All manufactured homes to be placed or substantially improved shall be anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not to be limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
Construction materials and methods.
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters;
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding; and
For all new construction and substantial improvements, the electrical, heating, ventilation, plumbing and air-conditioning equipment and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
All subdivision proposals and other proposed new development shall be consistent with the need to minimize flood damage;
All subdivision proposals and other proposed new development shall have public utilities and facilities, such as sewer, gas, electrical, and water systems, located and constructed to minimize flood damage;
All subdivision proposals and other proposed new development shall have adequate drainage provided to reduce exposure to flood damage; and
Base flood elevation data shall be provided for subdivision proposals and other proposed new development which contain at least 50 lots or five acres (whichever is less).
Enclosure openings. All new construction and substantial improvements having fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria: A minimum of two openings in at least two exterior walls of each enclosed area having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, or other covering or devices, provided that they permit the automatic entry and exit of floodwaters.
In all areas of special flood hazard where base flood elevation data have been provided as set forth in Section § 188-7, Basis for establishing areas of special flood hazard or in Section § 188-14B, Use of other base flood data, the following standards are required:
New construction and substantial improvement of any residential structure located in an A or AE Zone shall have the lowest floor, including basement, together with the attendant utilities and sanitary facilities, elevated at or above the base flood elevation, plus one foot, or as required by ASCE/SEI 24-14, Table 2-1, whichever is more restrictive
Within any AO or AH Zone on the municipality's FIRM, all new construction and substantial improvement of any residential structure shall have the lowest floor, including basement, together with the attendant utilities and sanitary facilities, elevated above the depth number specified in feet, plus one foot, elevated above the highest adjacent grade at least as high as the depth number specified in feet (at least two feet if no depth number is specified), and require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
Nonresidential construction. In an area of special flood hazard, all new construction and substantial improvement of any commercial, industrial or other nonresidential structure located in an A or AE Zone (For Coastal A Zone construction, see Subsection E, Coastal A Zone.) shall have the lowest floor, including basement, together with the attendant utilities and sanitary facilities, Either:
Elevated to or above the base flood elevation, plus one foot, or as required by ASCE/SEI 24-14, Table 2-1, whichever is more restrictive; require within any AO or AH Zone on the municipality's DFIRM to elevate above the depth number specified in feet, plus one foot, above the highest adjacent grade (at least three feet if no depth number is specified), and require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures; or:
Be floodproofed so that below the base flood level, plus one foot, or as required by ASCE/SEI 24-14, Table 6-1, whichever is more restrictive, the structure is watertight with walls substantially impermeable to the passage of water;
Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the applicable provisions of this subsection. Such certification shall be provided to the official as set forth in § 188-14C.
All manufactured homes to be placed or substantially improved within an area of special flood hazard shall be consistent with the need to minimize flood damage:
Be constructed to minimize flood damage;
Have adequate drainage provided to reduce exposure to flood damage; and
Be elevated on a permanent foundation such that the top of the lowest floor is at or above the base flood elevation, plus one foot, or as required by ASCE/SEI 24-14, Table 2-1, whichever is more restrictive.
Floodways. Located within areas of special flood hazard established in § 188-7 are areas designated as "floodways." Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless a technical evaluation demonstrates that encroachment shall not result in any increase in flood levels during the occurrence of the base flood discharge.
In all areas of special flood hazard in which base flood elevation data has been provided and no floodway has been designated, the cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than 0.2 of a foot at any point.
Coastal A Zone. Coastal A Zones are located within the areas of special flood hazard established in § 188-7. These areas may be subject to wave effects, velocity flows, erosion, scour, or a combination of these forces; therefore, the following provisions shall apply.
Elevation. All new construction and substantial improvements shall be elevated on piling or columns so that:
The bottom of the lowest horizontal structural member of the lowest floor (excluding the piling or columns) is elevated to or above the base flood elevation, plus one foot, or as required by ASCE/SEI 24-14, Table 4-1, whichever is more restrictive; and
All new construction and substantial improvements shall be securely anchored on piling or columns.
The pile or column foundation and structure attached thereto shall be anchored to resist flotation, collapse or lateral movement due to the effects of wind and water loading values each of which shall have a one-percent chance of being equaled or exceeded in any given year (one-hundred-year mean recurrence interval).
Prohibit the use of fill for structural support of buildings within Coastal A Zones on the community's FIRM.
Certification. A registered professional engineer or architect shall develop or review the structural design specifications and plans for the construction and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for compliance with the provisions of Subsection G.
Space below the lowest floor.
Any alteration, repair, reconstruction or improvement to a structure started after the enactment of this chapter shall not enclose the space below the lowest floor unless breakaway walls, open wood latticework or insect screening are used as provided for in this section.
Breakaway walls, open wood latticework or insect screening shall be allowed below the base flood elevation, provided that they are intended to collapse under wind and water loads without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system. Breakaway walls shall be designed for a safe loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading of 20 pounds per square foot (either by design or when so required by local or state codes) may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:
Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and
The elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement or other structural damage due to the effects of wind and water load acting simultaneously on all building components (structural and nonstructural). Water loading values used shall be those associated with the base flood. Wind loading values used shall be those required by applicable state or local building standards.
If breakaway walls are utilized, such enclosed space shall be used solely for parking of vehicles, building access, or storage and not for human habitation.
Prior to construction, plans for any breakaway wall must be submitted to the Construction Code Official or Building Subcode Official for approval.
Sand dunes. Prohibit man-made alteration of sand dunes within Coastal A Zones on the community's DFIRM which would increase potential flood damage.