In all special flood Hazard Areas (SFHAs) the following provisions are required:
A. 
New construction, substantial improvements, and repair to structures that have sustained substantial damage shall be constructed using methods and practices that minimize flood damage.
B. 
New construction, substantial improvements, and repair to structures that have sustained substantial damage shall be constructed with materials and utility equipment that are flood damage resistant and conform to the provisions of FEMA Technical Bulletin 2, Flood Damage Resistant Material Requirements. This includes, but is not limited to, flooring, interior and exterior walls, wall coverings and other materials installed below the base flood elevation plus one (1.0) foot.
C. 
New construction, substantial improvements, and repair to structures that have sustained substantial damage shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
D. 
New construction, substantial improvements, and repair to structures that have sustained substantial damage cannot be constructed or located entirely or partially over water unless it is a functionally dependent use or facility.
E. 
New and replacement electrical, heating, plumbing, ventilation and air conditioning equipment, appliances, fixtures and components, HVAC duct work and duct systems, and any other utility service equipment, facilities, machinery, or connections servicing a structure, shall be elevated so that the bottom of each shall be elevated one (1.0) foot above the base flood elevation (BFE). This includes, but is not limited to, furnaces, oil or propane tanks, air conditioners, heat pumps, hot water heaters, ventilation duct work, washer and dryer hook-ups, electrical junction boxes, and circuit breaker boxes. Systems, fixtures, equipment and components shall not be mounted on or penetrate through breakaway walls intended to fail under flood loads. Connections or other equipment that must be located below the BFE plus 1.0 foot elevation are permitted only when no other elevation alternative is available and provided they are designed and installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of the base flood event. Electrical wiring systems that must be located below the BFE plus one (1.0) foot shall conform to the standards for wet locations.
F. 
New and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
G. 
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharges from the system into floodwaters.
H. 
New and replacement on-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
I. 
In all flood zones, new and replacement underground tanks shall be anchored to prevent flotation, collapse and lateral movement under conditions of the base flood. In VE and Coastal AE zones, aboveground storage tanks which are located outside or inside of a structure must be elevated one (1.0) foot above the base flood elevation (BFE). Where elevated on platforms, the platforms shall be cantilevered from or knee braced to the building or shall be supported on elevated foundations that conform to the standards for the particular flood zone as described in § 174-20. In A and AE zones, aboveground storage tanks which are located outside or inside of a structure shall be elevated one (1.0) foot above the base flood elevation (BFE) or shall be securely anchored to prevent flotation, collapse or lateral movement under conditions of the base flood. Anchored tanks must have the top of the fill pipe located at least one (1.0) foot above the BFE and have a screw fill cap that does not allow for the infiltration of floodwater.
J. 
In any portion of a watercourse that is altered or relocated in conjunction with development activities, the flood-carrying capacity must be maintained. Notify adjacent communities and the Connecticut Department of Energy and Environmental Protection (DEEP), Land and Water Resources Division prior to any alteration or relocation of a watercourse.
K. 
If any portion of a structure lies within the special flood hazard area (SFHA), the entire structure is considered to be located within the SFHA and must meet the construction requirements of the flood zone. The structure includes any structurally attached additions, garages, decks, porches, sunrooms, patios or any other structure attached to the main structure.
L. 
If a structure lies within two or more flood zones, the construction standards of the most restrictive zone apply to the entire structure (i.e., the VE Zone is more restrictive than the AE Zone; structure must be built to the highest BFE). The structure includes any structurally attached additions, garages, decks, porches, patios, sunrooms, or any other structure attached to the main structure.
M. 
Compensatory storage. The water holding capacity of the floodplain, except those areas that are tidally influenced, shall not be reduced. Any reduction caused by filling, new construction or substantial improvements involving an increase in footprint to the structure, shall be compensated for by deepening and/or widening of the floodplain. Storage shall be provided on-site, unless easements have been gained from adjacent property owners; it shall be provided within the same hydraulic reach and a volume not previously used for flood storage; it shall be hydraulically comparable and incrementally equal to the theoretical volume of flood water at each elevation, up to and including the 100-year flood elevation, which would be displaced by the proposed project. Such compensatory volume shall have an unrestricted hydraulic connection to the same waterway or water body. Compensatory storage can be provided off-site if approved by the municipality.
N. 
Equal conveyance. Within the floodplain, except those areas which are tidally Influenced, as designated on the Flood Insurance Rate Map (FIRM) for the community, encroachments resulting from filling, new construction or substantial improvements involving an increase in footprint of the structure, are prohibited unless the applicant provides certification by a registered professional engineer demonstrating, with supporting hydrologic and hydraulic analyses performed in accordance with standard engineering practice, that such encroachments shall not result in any (0.00 feet) increase in flood levels (base flood elevation). Work within the floodplain and the land adjacent to the floodplain, including work to provide compensatory storage shall not be constructed in such a way so as to cause an increase in flood stage or flood velocity.
A. 
The Town Engineer shall require base flood elevation (BFE) data be provided with any application for new construction, substantial improvement, repair to structures which have sustained substantial damage or other development in Zone A without a FEMA-published BFE (unnumbered A Zone). A registered professional engineer must determine the BFE in accordance with accepted hydrologic and hydraulic engineering practices and document the technical methods used. Studies, analyses and computations shall be submitted in sufficient detail to allow thorough review and approval. The Town Engineer shall obtain, review and reasonably utilize any BFE and floodway data available from a federal, state or other source, including data developed for subdivision proposals, as criteria for requiring that new construction, substantial improvements, repair to structures which have sustained substantial damage or other development in unnumbered A Zones on the community's Flood Insurance Rate Map (FIRM) meet the standards in §§ 174-16 and 174-20. If no BFE can be determined, the lowest floor, including basement, must be elevated to three feet above the highest adjacent grade next to the structure.
B. 
When BFEs have been determined within Zone AE on the community's FIRM but a regulatory floodway has not been designated, the Town Engineer must require that no new construction, substantial improvements, repair to structures which have sustained substantial damage or other development, including fill, shall be permitted which will increase the water surface elevation of the base flood more than one (1.0) foot at any point within the community when all existing and anticipated development is considered cumulatively with the proposed development.
C. 
The Town Engineer may request floodway data of an applicant for watercourses without FEMA-published floodways. When such data is provided by an applicant or whenever such data is available from any other source (in response to the municipality's request or not), the community shall adopt a regulatory floodway based on the principle that the floodway must be able to convey the waters of the base flood without increasing the water surface elevation more than one (1.0) foot at any point within the community.
D. 
The Town Engineer shall obtain, review and reasonably utilize any BFE and floodway data available from a federal, state or other source, as criteria for requiring that new construction, substantial improvements, repair to structures which have sustained substantial damage or other development in any area of potential, demonstrable or historical flooding within the community meet the standards in §§ 174-16 and 174-20.
E. 
Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in Zones AE and AH, on the community's FIRM which increases the water surface elevation of the base flood by more than one (1.0) foot, provided that the community first completes all of the provisions required by Section 65.12.
A. 
Construction standards in special flood hazard areas (SFHA), Zones A and AE.
(1) 
Residential construction.
(a) 
All new construction, substantial improvements, and repair to structures that have sustained substantial damage which are residential structures shall have the bottom of the lowest floor, including basement, elevated one (1.0) foot above the base flood elevation (BFE). Electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one (1.0) foot above the BFE.
(2) 
Nonresidential construction.
(a) 
All new construction, substantial improvements, and repair to structures that have sustained substantial damage which are commercial, industrial or nonresidential structures shall:
[1] 
Have the bottom of the lowest floor, including basement, elevated one (1.0) foot above the base flood elevation (BFE); or
[2] 
In lieu of being elevated, nonresidential structures may be dry floodproofed to one (1.0) foot above the BFE provided that together with all attendant utilities and sanitary facilities the areas of the structure below the required elevation are watertight with walls substantially impermeable to the passage of water, and provided that such structures are composed of structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. A registered professional engineer or architect shall review and/or develop structural design specifications and plans for the construction, and shall certify that the design and methods of construction are in accordance with acceptable standards of practice for meeting the provisions of this section. Such certification shall be provided to the Town Engineer on the FEMA floodproofing certificate, Form 81-65.
[3] 
Electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one (1.0) foot above the BFE.
(3) 
Fully enclosed areas below the base flood elevation of elevated buildings.
(a) 
All new construction, substantial improvements, or repair to structures that have sustained substantial damage, whether residential or nonresidential, that include fully enclosed areas formed by a foundation and other exterior walls shall have the lowest floor elevated to one (1.0) foot above the base flood elevation (BFE). The elevated building shall be designed to preclude finished living space below the lowest floor and be designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls (wet floodproofing). Designs for complying with this requirement must either be certified by a registered professional engineer or architect as meeting the requirements of ASCE 24 Section 2.6.2.2, or meet the following minimum criteria listed in Subsection A(3)(a)(1) through [8] below:
[1] 
Provide a minimum of two openings (hydraulic flood vents) having a total net area of not less than one square inch for every one square foot of enclosed area subject to flooding. The enclosed area is measured on the exterior of the enclosure walls. These hydraulic openings must be located on at least two different exterior walls of each enclosed area. If the structure has more than one enclosed area, openings must be installed in the exterior walls of each enclosed area so that floodwaters can enter directly from the outside;
[2] 
The bottom of all openings shall be no higher than one one (1.0) above the higher of either the final interior grade or floor elevation, or the finished exterior grade adjacent to the outside of the foundation wall. At least one entire side of the structure's fully enclosed area must be at or above grade. Fill placed around the foundation walls must be graded so that the elevation inside the enclosed area is equal to or higher than the adjacent outside elevation on at least one side of the building. The finished floor of the enclosed area shall be no lower than the bottom of the foundation openings. The foundation slab of a residential structure, including the slab of a crawlspace, must be set equal to the outside finished grade on at least one side of the building;
[3] 
The openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic entry and exit of floodwaters in both directions without any external influence or control such as human intervention, including the use of electrical and other nonautomatic mechanical means. These coverings must not block or impede the automatic flow of floodwaters into and out of the enclosed area. Other coverings may be designed and certified by a registered professional engineer or approved by the Town Engineer;
[4] 
Openings shall not be less than three inches in any direction in the plane of the wall;
[5] 
The area cannot be used as finished living space. Use of the enclosed area shall be the minimum necessary and shall only be used for the parking of vehicles, building access or limited storage. Access to the enclosed area shall be the minimum necessary to allow for the parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator). The enclosed area shall not be used for human habitation;
[6] 
All interior walls, floor, and ceiling materials located below one (1.0) foot above the BFE shall be unfinished and flood damage resistant in accordance with FEMA Technical Bulletin 2, Flood Damage Resistant Requirements.
[7] 
Electrical, plumbing, HVAC duct work, machinery or other utility equipment and connections that service the structure (including, but not limited to, furnaces, oil or propane tanks, air conditioners, heat pumps, hot water heaters, ventilation, washer and dryer hook-ups, electrical junction boxes, circuit breaker boxes and food freezers) are prohibited in the fully enclosed area below the BFE plus one (1.0) foot. Utilities or service equipment located in this enclosed area, even if elevated to one (1.0) foot above the BFE in the space, may subject the structure to increased flood insurance rates.
[8] 
A residential building with a structurally attached garage having the floor slab below the BFE is considered an enclosed area below the BFE and must meet the standards of § 174-20A(3)(a)[1] through [7]. A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters in both directions. Flood openings or vents are required in the exterior walls of the garage or in the garage doors. Garage doors that must be manually opened do not meet the flood vent opening requirements in § 174-20A(3)(a)[1] through [3]. In addition to the automatic entry of floodwaters, the areas of the garage below BFE plus one (1.0) foot must be constructed with flood damage-resistant materials per the requirements of FEMA Technical Bulletin 2. Garages attached to nonresidential structures must also meet the aforementioned requirements or be dry floodproofed as per the requirements of § 174-20A(2).
B. 
Construction Standards in Coastal High-Hazard Areas, Zones VE and Coastal AE.
(1) 
Located within the special flood hazard areas (SFHA) are areas designated as coastal high-hazard areas. These areas have additional flood hazards associated with wave wash, erosion scour, and high wind. Therefore, the following provisions shall apply:
(a) 
All new construction, substantial improvement and repair to structures that have sustained substantial damage shall be located landward of the reach of the Coastal Jurisdiction Line as defined in C.G.S. § 22a-359 as amended by Public Act 12-101.
(b) 
All new construction, substantial improvement and repair to structures that have sustained substantial damage shall be elevated so that the bottom of the lowest horizontal structural member (excluding pilings, pile caps, and columns) is elevated at least one (1.0) foot above the base flood elevation (BFE), with all space below the lowest horizontal supporting member open and free of obstruction so as not to impede the flow of water. Basement floors that are below ground on all sides are prohibited.
(c) 
New or replacement electrical, plumbing, machinery or other utility equipment that service the structure shall be placed so that the bottom of each is elevated one (1.0) foot above the BFE and cannot be located below the structure. Any service equipment that must be located below the BFE must be floodproofed to prevent water from entering during conditions of flooding. Electrical, mechanical and plumbing system components are not to be mounted on or penetrate through walls designed to break away under flood loads.
(d) 
All new construction, substantial improvement and repair to structures that have sustained substantial damage shall be securely anchored on pilings or columns.
(e) 
New and replacement pilings and columns and the attached structures shall be anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. The anchoring and support system shall be designed with wind and water loading values required by applicable state or local building codes.
(f) 
A registered professional engineer or architect shall develop structural specifications and plans for the construction and shall certify that the design, specifications and plans for construction are in accordance with acceptable standards and are in compliance with the provisions contained in § 174-20B(1) through (5).
(g) 
There shall be no fill used for structural support. Minor grading and the placement of minor quantities of noncompacted fill shall be permitted for landscaping and drainage purposes under and around buildings, and for support of parking slabs, pool decks, patios and walkways installed at current grade. The fill must wash out from storm surge, thereby rendering the building free of obstruction, prior to generating excessive loading forces, ramping effects, or wave deflection. The Town Engineer shall approve design plans for landscaping/aesthetic fill only after the applicant has provided an analysis by a registered professional engineer, architect and/or soil scientist, which demonstrates that the following factors have been fully considered:
[1] 
Particle composition of fill material does not have a tendency for excessive natural compaction;
[2] 
Volume and distribution of fill will not cause wave deflection to adjacent properties; and
[3] 
Slope of fill will not cause wave run-up or ramping.
(h) 
There shall be no alteration of sand dunes that would increase potential flood damage.
(i) 
Prior to construction, plans for any structures that will have breakaway walls, lattice work or insect screening must be submitted to the Town Engineer for approval.
(j) 
Nonsupporting breakaway walls, lattice work or mesh screening shall be allowed below the base flood elevation provided it is not part of the structural support of the structure and is designed so as to break away, under abnormally high tides or wave action, without damage to the structural integrity of the structure on which it is to be used and provided the following design specifications are met:
[1] 
Design safe loading resistance of each wall shall not be less than 10 pounds per square foot or more than 20 pounds per square foot; or
[2] 
If more than 20 pounds per square foot, a registered professional engineer or architect shall certify that the design wall collapse would result from a water load less than that which would occur during the base flood event, 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 loads acting simultaneously on all building components prior to or during the collapse of such wall. Enclosures of 300 square feet or more are subject to increased insurance premiums.
(k) 
Areas enclosed by breakaway walls shall contain hydraulic flood vents per the requirements of § 174-20A(3).
(l) 
If breakaway walls, lattice work or insect screening are utilized, the resulting enclosed space shall not be designed to be used for human habitation, but shall be designed to be used only for parking of vehicles, building access, or limited storage. Enclosures of 300 square feet or more are subject to increased insurance premiums.
(m) 
Any alteration, repair, reconstruction, or improvement to a structure shall not enclose the space below the lowest floor except with breakaway walls, lattice work, or insect screening as provided for in § 174-20B(8) and (9).
(n) 
All new construction, substantial improvement and repair to structures that have sustained substantial damage, shall have an exterior door installed at the top of the stairs that provides access to the lowest (habitable) floor of the structure and protects the building envelope.
(o) 
All new construction, substantial improvements and repair to structures that have sustained substantial damage shall not extend the base of a chimney or fireplace below the BFE plus one foot. When vertical support is required, a chimney or fireplace shall be vertically supported on pile or column foundations embedded at least as deep as the rest of the structure foundation or deeper where needed to support the chimney against water and wind loads. The chimney and fireplace system shall be designed to minimize transfer of water and wind loads to the structure or structure foundation.
C. 
Manufactured (Mobile) Homes and Recreational Vehicles (RVs).
(1) 
In special flood hazard areas (SFHA) with Zones A and AE, any manufactured (mobile) home to be newly placed, undergoing a substantial improvement or repaired as a result of substantial damage, shall be elevated so that the bottom of the frame is located one (1.0) foot above the base flood elevation (BFE). The manufactured home must also meet all the construction standards for Zones A and AE as per § 174-20A. The foundation and anchorage of manufactured homes to be located in floodways shall be designed and constructed in accordance with ASCE 24. This includes SFHAs outside a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an existing manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or on a site in an existing manufactured home park in which a manufactured home has incurred substantial damage as a result of a flood.
(2) 
In special flood hazard areas (SFHA) with Zones VE and Coastal AE, any manufactured (mobile) home to be newly placed, undergoing a substantial improvement or repaired as a result of sustained substantial damage, shall be elevated so that the bottom of the lowest horizontal structural member located one (1.0) foot above the base flood elevation (BFE). The manufactured home must also meet all the construction standards for Zones VE and Coastal AE as per § 174-20B. This includes SFHAs outside a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an existing manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or on a site in an existing manufactured home park in which a manufactured home has incurred substantial damage as a result of a flood.
(3) 
All manufactured (mobile) homes within SFHA shall be placed on a permanent foundation which itself is securely anchored and to which the structure is securely anchored so that it will resist flotation, lateral movement and hydrostatic pressures. Anchoring may include, but not be limited to, the use of over-the-top or frame ties to ground anchors.
(4) 
All manufactured (mobile) homes within SFHA shall be installed using methods and practices that minimize flood damage. Adequate access and drainage should be provided. Elevation construction standards include piling foundations placed no more than 10 feet apart, and reinforcement is provided for piers more than six feet above ground level.
(5) 
Recreational vehicles placed on sites within Zones A and AE in the SFHA shall either be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use, or meet all the general standards of § 174-18 and the elevation and anchoring requirement of § 174-20C(1) through (4). 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.
(6) 
Recreational vehicles placed on sites within Zone VE and Coastal AE in the SFHA shall either be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use, or meet all the general standards of § 174-18, the VE and Coastal AE Zone construction requirements of § 174-20B, and the elevation and anchoring requirement of § 174-20C(2) through (4). 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.
D. 
Floodways.
(1) 
Located within special flood hazard areas (SFHA) are areas designated as floodways on the community's Flood Insurance Rate Maps (FIRM) or Flood Boundary and Floodway Maps (FBFM). Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles and has erosion potential, no encroachments, including fill, new construction, substantial improvements, repairs to substantially damaged structures and other developments shall be permitted unless certification, with supporting technical data, by a registered professional engineer is provided demonstrating, through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, that encroachments shall not result in any (0.00 feet) increase in flood levels during occurrence of the base flood discharge published by FEMA. Buildings and structures meeting the standard above and located in whole or in part in the floodway shall be designed and constructed in accordance with ASCE 24. Fences in the floodway must be aligned with the flow and be of an open design. A permit may be given which allows encroachments resulting in increases in base flood elevations provided the community first obtains a conditional floodway revision by meeting the requirements of C.F.R. 44, Chapter 1, Subsection 65.12.