5.3.E General Requirements

In all Special Flood Hazard Areas, the following provisions shall apply in addition to those set forth elsewhere in these Regulations:

  • A Floodplain Development Permit shall be required in conformance with the provisions of this Section prior to the commencement of any development activities. Permits issued under this Section shall expire if actual construction of a permitted structure does not commence within one hundred and eighty (180) days of the permit approval date.
  • All applications for building permits within the flood hazard area shall include with the application the base flood elevation data from the FIRM for that portion of the activity located within the flood hazard area.
  • The Commission shall review plans for new developments requiring Site Plan approval or Special Permit in order to determine whether such development is consistent with the need to minimize flood damage within the flood prone areas and to determine whether proposed developments and building sites will be reasonably safe from flooding. Special consideration shall be given to the placement of public utilities and the provision of adequate drainage to reduce exposure of flood hazards.
  • In riverine situations, the Planning and Zoning Commission shall notify adjacent communities and the Connecticut Department of Energy and Environmental Protection (DEEP) prior to approving any activity involving alterations or relocation of the watercourse and submit copies of such notice to the Federal Emergency Management Agency. In any portion of a watercourse that is altered or relocated, the flood carrying capacity must be maintained.
  • All building permits for new construction, substantial improvements (including placement of prefabricated buildings), or other development shall require, as a condition of building permit approval, confirmation by the Zoning and Building Official that the development is designed and constructed so as to minimize flood damage.
  • The Zoning and Building Official shall record the as-built elevation (in relation to mean sea level) of the lowest floor (including basement) of all new construction or substantially improved structures and shall record the elevation (in relation to mean sea level) to which the new or substantially improved structures have been flood proofed. In coastal high hazard areas (VE zones), the Zoning and Building Official shall record the elevation of the bottom of the lowest horizontal structural member for all new construction and substantial improvements to structures. All records pertaining to the provisions of these Regulations shall be maintained on file.
  • The bottom of all 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 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 1.0 foot shall conform to the standards for wet locations.
  • 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.
  • New construction or substantial improvements shall be constructed by methods and practices that minimize flood damage.
  • 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 designated to minimize or eliminate infiltration of floodwaters into the systems and discharges from the system into flood waters.
  • On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
  • All manufactured homes to be placed within Zone A, AE and VE on the City's FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not 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.
  • New construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
  • When base flood elevation data or floodway data have not been provided, the Planning and Zoning Commission 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 the provisions of this regulation. A registered professional engineer, at the applicant's expense, 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.

5.3.F Site Plan and Building Permit Requirements

  • On all Site Plan and building permit applications for development in the Special Flood Hazard Areas, the following information is required:
  • Elevation in relation to mean sea level of the proposed lowest floor (including basement) of all structures;
  • Elevation in relation to mean sea level to which any non-residential structure will be flood-proofed;
  • Description to the extent to which any watercourse will be altered or relocated as a result of proposed development;
  • Assurances that the flood carrying capacity of any watercourse and its related flood plain is maintained;
  • Copies of all applicable Federal and State permits shall be included with the building permit.
  • For non-residential structures certification at time of building permit application shall be provided to the Zoning and Building Official on the FEMA Floodproofing Certificate, Form 81-65 and in accordance with 5.3.G.2.b below.

5.3.G Requirements in Zones A & AE

  • Residential - 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.
  • Non-Residential - All new construction, substantial improvements, and repair to structures that have sustained substantial damage which are commercial, industrial or non-residential structures shall:
    • Have the bottom of the lowest floor, including basement, elevated one (1.0) foot above the base flood elevation (BFE); or
    • In lieu of being elevated, non-residential structures may be dry flood-proofed 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.
    • Electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one (1.0) foot above the BFE.
  • Wet Flood-proofing - All new construction, substantial improvements, or repair to structures that have sustained substantial damage, whether residential or non-residential, 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 flood waters to automatically equalize hydrostatic flood forces on exterior walls (wet flood-proofing). 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 sections (a)-(h) below:
    • 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. These hydraulic openings must be located on at least two different walls. Only the area (square footage) that lies below the base flood elevation can be used in the calculation of net area of vents required. If the structure has more than one enclosed area, openings must be installed in the exterior walls of each enclosed area so that flood waters can enter directly from the outside;
    • The bottom of all openings shall be no higher than one foot above the finished 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;
    • The openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic entry and exit of flood waters in both directions without any external influence or control such as human intervention, including the use of electrical and other non-automatic 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 Zoning and Building Official;
    • Openings shall not be less than three inches in any direction in the plane of the wall;
    • e. 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 or partitioned into separate rooms;
    • All interior walls, floor, and ceiling materials located below the base flood elevation shall be unfinished and resistant to flood damage in accordance with FEMA Technical Bulletin 2, Flood Damage-Resistant Requirements.
    • Electrical, plumbing, HVAC ductwork, 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 base flood elevation. Utilities or service equipment located in this enclosed area, even if elevated above the base flood elevation in the space, will subject the structure to increased flood insurance rates.
    • 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 Sections 5.3.G.4 (a)-(g). 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 Section 5.3.G.4 (a)-(c). 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 non-residential structures must also meet the aforementioned requirements or be dry floodproofed as per the requirements of Section 5.3.G.2.b.

5.3.H Requirements in Zone VE & Coastal AE (Coastal High Hazard Areas)

  • The provisions of Section 5.3.G shall also apply in the VE zone unless specifically modified by this Subsection.
  • All new construction or substantial improvement shall be located landward of the reach of the Connecticut Coastal Jurisdiction Line as defined in CGS 22a-359 as amended by Public Act 12-101.
  • 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.
  • The bottom of all electrical, plumbing, machinery or other utility equipment that service the structure must be 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 breakaway under flood loads.
  • All new construction or substantial improvement shall be elevated so that the bottom of the lowest supporting horizontal member (excluding pilings or columns) is located above the base flood elevation plus one foot, with all space below the lowest supporting member open as not to impede the flow of water.
  • All new construction or substantial improvement shall be securely anchored on pilings or columns.
  • All pilings and columns and the attached structures shall be anchored to resist flotation, collapse, and lateral movement due to the effect 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 which equal or exceed the one hundred year mean recurrence interval (1% annual chance floods and winds).
  • 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, specifications and plans for construction are in accordance with acceptable standards.
  • There shall be no fill used as structural support. Minor grading and the placement of minor quantities of non-compacted 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 Zoning and Building Official shall approve design plans for landscaping/aesthetic fill only after the applicant has provided an analysis by an engineer, architect and/or soil scientist, which demonstrates that the following factors have been considered:
    • Particle composition of fill material does not have a tendency for excessive natural compaction;
    • Volume distribution of fill will not cause wave deflection to adjacent properties; and
    • Slope of fill will not cause wave run-up or ramping.
  • Non-supporting 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 building and is designed so as to break away under abnormally high tides or wave action without damage to the structural integrity of the building on which it is to be used and provided the following specifications are met:
    • Design safe loading resistance of each wall shall be not less than 10 nor more than 20 pounds per square foot; or
    • 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 during the base flood event.
    • Maximum wind and water loading values to be used in this determination shall each have 1% chance of being equaled or exceeded in any given 100-year mean recurrence interval.
    • Areas enclosed by breakaway walls shall contain hydraulic flood vents per the requirements of Section 5.3.G.4.
  • If breakaway walls, lattice work or 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 of maintenance equipment used in connection with the premises.
    • Prior to construction, plans for any structures that will have breakaway walls, lattice work or screening must be submitted to the Zoning and Building Official for approval.
    • Any alteration, repair, reconstruction or improvement to a structure shall not enclose the space below the lowest floor except with breakaway walls, latticework, or screening, as provided in Section 5.3.G.4.
    • 14. There shall be no alteration of sand dunes (naturally occurring accumulations of sand in ridges or mounds landward of the beach) which would increase potential flood damage.
  • To protect the building envelope, an exterior door shall be installed at the top of the stairs that provides access to the lowest (habitable) floor of the structure.
  • The base of a chimney or fireplace shall not extend 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.

5.3.I Requirements for Floodways

  • Within areas designated as floodways on the FIRM or other available source, encroachments, including fill, new construction, substantial improvements, and other developments, are prohibited unless certification with supporting technical data, by a Connecticut registered professional engineer is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, that the encroachments shall not result in any (0 feet) increase in flood levels during occurrence of the base flood discharge.
  • 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.
  • The City 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 City's request or not), the City 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 1 foot at any point within the community.
  • In Zone A when base flood elevations become available and in Zone AE when base flood elevations have been determined, but before a regulatory floodway is designated, no new construction, substantial improvement, or other development (including fill) shall be permitted which will increase the water surface elevation of the base flood elevations more than 1 foot at any point the community when all existing and anticipated development is considered cumulatively with the proposed development.

5.3.J Additional Provisions

  • 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 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.
  • Compensatory Storage
    • The water holding capacity of the floodplain, except those areas which 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.
    • Such compensatory volume shall have an unrestricted hydraulic connection to the same waterway or water body.
    • Storage shall be:
  • Provided on-site, unless easements have been gained from adjacent property owners;
  • Provided within the same hydraulic reach and a volume not previously used for flood storage;
  • 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.
    • Compensatory storage can be provided off-site if approved by the municipality.
  • Aboveground and Underground Storage Tanks
    • In all flood zones, underground tanks shall be anchored to prevent flotation, collapse and lateral movement under conditions of the base flood.
    • In VE and Coastal AE zones, above-ground 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 Section 5.3.
    • In A and AE zones, above-ground 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 flood water.
  • Portion of Structure in Flood Zone
    • If any portion of a structure lies within the Special Flood Hazard Area (SFHA), the entire structure is considered to be in the SFHA and the entire structure must meet the construction requirements of the flood zone.
    • The structure includes any attached additions, garages, decks, sunrooms, or any other structure attached to the main structure.
    • Decks or porches that extend into a more restrictive flood zone will require the entire structure to meet the standards of the more restrictive zone.
  • Structures in Two Flood Zones
    • 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., V zone is more restrictive than A zone; structure must be built to the highest BFE).
    • The structure includes any attached additions, garages, decks, sunrooms, or any other structure attached to the main structure.
    • Decks or porches that extend into a more restrictive zone will require the entire structure to meet the requirements of the more restrictive zone.
  • No Structures Entirely or Partially Over Water - 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.
  • Manufactured Homes (Existing Park) - Manufactured homes placed or substantially improved in an existing manufactured home park within A, AE, Coastal AE, and VE zones shall be elevated so that:
    • The lowest floor is at or above the base flood elevations;
    • The chassis is supported by reinforced piers no less than 36 inches above grade and securely anchored; and
    • The installation meets the requirements of Section 5.3.E.12.
  • Manufactured Homes (Other Locations) - Manufactured homes placed or substantially improved within A, AE, Coastal AE and VE zones shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation plus one foot and meet the requirements of Section 5.3.E.13 if situated in one of the following locations:
    • Outside a manufactured home park or subdivision;
    • In a new manufactured home park or subdivision;
    • In an expansion to an existing manufactured home park or subdivision;
    • On a site in an existing park which a manufactured home has incurred substantial damage as a result of a flood.
  • Recreational Vehicles - In A, AE, Coastal AE, and VE zones, all recreational vehicles to be placed on a site must:
    • Be elevated and anchored, meeting the requirements of Section 5.3.E.13; or
    • Be on the site for less than 180 consecutive days, be fully licensed, and be ready for highway use as evidenced by:
  • Being on its wheels or a jacking system, is
  • Being attached to the site only by quick disconnect type utilities and security devices, and
  • Having no permanently attached additions.

5.3.K Floodplain Variances

  • A floodplain variance shall not be granted if the Zoning Board of Appeals determines that:
    • No exceptional hardship would result from failure to grant the variance;
    • Granting the variance would result in increased flood heights, additional threats to the public safety, extraordinary public expense, or creation of a nuisance.
    • Within any designated floodway, an increase in flood levels during the base flood discharge would occur as a result of such variance.
  • A floodplain variance may be issued for new construction and substantial improvement and other development necessary for the conduct of a functionally-dependent use provided the structure or other development is protected by methods that minimize flood damage and create no additional threat to public safety.
  • An applicant for a floodplain variance to this Section 5.3 shall be notified by the Zoning and Building Official that the issuance of a floodplain variance to construct a structure below the base flood elevation will result in increased rates for insurance coverage, and that a record of all flood protection variance action and resulting construction shall be maintained.
  • Any applicant to whom a floodplain variance is granted shall be given written notice specifying the difference between the base flood elevation and the elevation to which the structure is to be built and stating that the cost of risk resulting from the reduced lowest floor elevation up to amounts as high as $25 for $100 of insurance coverage.
  • The Zoning and Building Official shall maintain a record of all flood protection variance actions, including justification for their issuance, and biennial report such variances issued in the annual report submitted to the Federal Emergency Management Agency