Town of Old Saybrook, CT Provisions for Flood Hazard Reduction

The bottom of all electrical, heating, plumbing, ventilation and air-conditioning equipment, appliances, fixtures and components, HVAC ductwork and duct systems, and any other utility service equipment, facilities, machinery or connections serving a structure shall be elevated two feet above the base flood elevation (BFE). This includes, but is not limited to, furnaces, air conditioners, heat pumps, hot water heaters, ventilation ductwork, washer and dry hook-ups, gas regulator valves located both on the house and on the tank, electrical meters, electrical junction boxes and circuit breaker boxes. Systems, fixtures, equipment and components shall not be mounted on or penetrate through breakway walls intended to fail under flood loads.

Connections or other equipment that must be located below the BFE plus two feet in elevation are permitted only when no other alternative is available and provided that they are installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effect of buoyancy, during the occurrence of the base flood event plus two feet. Electrical wiring systems that must be located below the BFE plus two feet shall conform to the standards for wet locations. Such systems shall only be permitted to the extent required by code for life/safety compliance.

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 discharges from the system into floodwaters;

On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding; and

In any portion of a watercourse which is altered or relocated, the flood-carrying capacity shall be maintained:

Accessory structures and swimming pools.

In Zones A, AE, AO and AH, the requirement of § 128-20B(1) and (2) shall not apply to the following:

[Amended 7-13-2021]

(Reserved)

Accessory structures and swimming pools which are less than 401 square feet in floor area and are accessory to a residential structure; and

One-story row garages located on a lot in a residential district containing multiple dwelling units.

Accessory buildings and attached garages as defined in § 128-18I(1) shall conform to the following:

Shall not be used for human habitation;

Shall be designed to have low flood damage potential and constructed with flood-resistant materials below the base flood elevation;

Shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters;

(d)

Shall be firmly anchored to prevent flotation which may result in damage to their structures;

(e)

Shall have all service facilities, such as electrical and heating equipment, designed and/or located so as to prevent water from entering or accumulating within components during conditions of flooding or elevated above base flood elevation; and

(f)

There shall be no basement or excavated area below any accessory building or garage.

Manufactured homes. Manufactured homes are prohibited in all special flood hazard areas.

Fuel tanks.

[Amended 7-13-2021]

In all flood zones, above-ground storage tanks (oil, propane, etc.) which are located outside or inside of the structure must either be elevated two feet above the base flood elevation (BFE) or be securely anchored with tie-down straps to prevent flotation, collapse or lateral movement. Where elevated on platforms, tanks will be cantilevered from the building or supported on elevated foundation that conforms to the standards for the particular flood zone as described in § 128-20. Anchored tanks must have the top of the fill pipe located at least two feet above the BFE and have a screw fill cap that does not allow for the infiltration of floodwater.

Below-ground fuel tanks shall be anchored to counteract the buoyancy force exerted by fully saturated soil during a flood. The top of all fuel oil tank fill and vent pipes, and vent pipes for gas regulator or pressure release valves, shall extend two feet above the BFE.

Portion of structure in flood zone. If any portion of a structure lies within or cantilevers into the special flood hazard area (SFHA), the entire structure is considered to be in the SFHA. The entire structure must meet the construction requirements of the flood zone. The structure includes any attached additions, garages, decks, sunrooms, patios six inches in height from natural grade 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.

[Amended 7-13-2021]

Structures in two flood zones. If a structure lies within or cantilevers into two or more flood zones, the construction standards of the most restrictive zone apply to the entire structure (i.e., VE Zone is more restrictive than AE Zone; structure must be built to two feet above 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.)

[Amended 7-13-2021]

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 storage or flood velocity.

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 floodwater at each elevation, up to and including the one-hundred-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.

§ 128-19 Standards for stream without established base flood elevations, floodways and/or flood mapping.

The Town Engineer shall obtain, review and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, including data developed pursuant to § 128-17A(6) or § 128-21D of this chapter, as criteria for requiring that new construction, substantial improvements, or other development in Zone A on the community's FIRM meet the standards in § 128-20. This does not relieve the applicant's responsibility for providing base flood elevation or floodway data with every application.

[Amended 7-13-2021]

In A Zones where base flood elevations have been determined, but before a floodway is designated, no new construction, substantial improvement, or other development, including fill, shall be permitted which will increase base flood elevations more than one foot at any point along the watercourse when all anticipated development is considered cumulatively with the proposed development.

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 Town's Engineer request or not, the Town of Old Saybrook 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 foot at any point along the watercourse.

The Town Engineer shall obtain, review and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, as criteria for requiring that new construction, substantial improvements, or other development in any area of potential, demonstrable or historical flooding within the community meet the standards in § 128-20.

§ 128-20 Specific standards.

In all special flood hazard areas A and AE, where base flood elevation data has been provided, the following provisions shall apply in addition to all general standards contained in § 128-18.

Residential construction. New construction, substantial improvements, or repair of any residential structure shall have the lowest floor, including basement, elevated at least two feet above the base flood elevation. If an existing residential structure has a current elevation above the BFE and meets the requirements of this chapter and FEMA standards, the structure will not be required to elevate the two additional feet above the BFE.

[Amended 7-13-2021]

Nonresidential construction.

[Amended 7-13-2021]

New construction, substantial improvements, and repair to structures that have substantial damage of any commercial, industrial, or nonresidential structure located in Zone A or AE shall have the lowest floor, including basement, elevated at least two feet above the base flood elevation; or

Nonresidential structures located in all A and AE Zones may be dry floodproofed at least two feet above the base flood elevation in lieu of being elevated, 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 use 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 subsection. Such certification shall be provided to the Old Saybrook Town Engineer on the FEMA floodproofing certificate, Form 81-65.

Fully enclosed areas below base flood elevation. New construction, substantial improvements, and repair to structures that have sustained substantial damage, whether residential or nonresidential, in A and AE Zones that include fully enclosed areas formed by foundation and other exterior walls located below the base flood elevation, excluding basements, shall be designed to preclude finished living below the lowest floor and designed to allow for the automatic entry and exit of floodwaters to equalize hydrostatic flood forces on exterior walls. An enclosed area below the base flood elevation that meets the design criteria specified below is not considered the lowest floor of the structure.

[Amended 7-13-2021]

Designs for complying with this requirement must meet the following minimum criteria:

Provide a minimum of two openings, located on at least two different 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, with the enclosed area measured on the exterior of the enclosure walls;

The bottom of all openings shall be not higher than one foot above the slab elevation and set at or above the exterior ground elevation so as to permit free drainage away from the structure;

Openings may be equipped with screens, louvers, valves or other coverings or devices, provided they permit the automatic flow of floodwaters in both directions without any external influence or human intervention. Other coverings must be designed and certified by an engineer and approved by the Old Saybrook Town Engineer. The exterior grade shall be at or below the interior slab elevation across the entire length of at least one side of the structure.

Electrical, plumbing, HVAC (including duct work) and other utilities are prohibited below the base flood elevation; and

(3)

Use of the enclosed area shall be the minimum necessary to allow for parking of vehicles or limited storage of maintenance equipment used in connection with the premises or entry to the living area via a stairway or elevator.

Coastal high-hazard areas. The following additional standards are applicable to development, including new construction, substantial improvement, and repair to structures that have sustained substantial damage, in the Zone VE and Zone AE bounded by a line labeled "Limit of Moderate Wave Action (LiMWA) portion of Special Flood Hazard Areas":

[Amended 7-13-2021]

All buildings and structures shall be located landward of the reach of the Connecticut Coastal Jurisdiction Line as defined in C.G.S. § 22a-359, as amended by Public Act 12-101;

All buildings or structures shall be elevated so that the lowest supporting horizontal member is located no lower than two feet above the base flood elevation and with all space below the lowest supporting horizontal member open so as not to impede the flow of water, except for breakaway walls as defined in § 128-6 and provided for in § 128-20D(5);

(3)

All buildings and structures shall be securely anchored on pilings or columns. 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 (one-percent annual chance floods and wind). There shall be no fill used for structural support;

(4)

Compliance with the provision of § 128-20D(2) and (3) shall be certified by a registered professional engineer or architect, as designed in accordance with ASCE24 Flood Resistant Design and Construction, which certification shall be provided to the Town Engineer as set forth in § 128-16B(1)(j);

(5)

Space below lowest floor. The following are applicable to any new construction, substantial improvements, repair to structures that have sustained substantial damage, and to any alteration, repair, reconstruction or improvement to a structure started after June 26, 1978:

There shall be no enclosure of the space below the lowest floor unless breakaway walls are used;

Breakaway walls are allowed below the base flood elevation, provided that they include flood vents, are not a part of the structural support of the building and are designed with a safe loading resistance of not less than 10 and not more than 20 pounds per square foot, so as to break away, under abnormally high tides or wave action, without damage to the structural integrity of the building on which they are to be used;

If breakaway walls are utilized, such enclosed space shall not be used for human habitation, but shall be designed to be used for parking of vehicles, or limited storage of maintenance equipment used in connection with the premises; and

(d)

Prior to construction, plans for any structure that will have breakaway walls, including flood vents, must be submitted to the Town Engineer for approval.

(NOTE: Breakaway enclosures of 300 square feet or more are subject to substantially higher flood insurance premiums than enclosures of 299 square feet or less.)

(e)

No fill shall be used for structural support.

(6)

Alteration of sand dunes in Zone VE is prohibited.

Manufactured (mobile) homes and recreational vehicles.

Manufactured (mobile) homes are prohibited in all special flood hazard areas (SFHAs). This includes SFHAs in 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, or on a site in an existing park in which a manufactured home has incurred substantial damage as a result of a flood.

Recreation vehicles placed on a site in an SFHA for 180 consecutive days or longer and intended to be improved property are prohibited. Recreational vehicles placed on site in an SFHA for fewer than 180 consecutive days must be fully licensed and ready for highway use. A recreational vehicle is ready for highway use if it is on its wheel or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions.

Floodways. Located within special flood hazard areas established in § 128-8 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris and potential projectiles and have erosion potential, no encroachments, including fill, new construction, substantial improvements and other developments, shall be permitted unless certification, along with supporting technical data provided by a registered professional engineer, is submitted demonstrating that encroachments shall not result in any (0.00 feet) increase in flood levels during occurrence of the base flood discharge. Fences located 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 requirement of 44 CFR, Chapter 1, Subsection 65.12.

Critical facilities.

New construction of critical facilities shall be elevated or dry floodproofed to the base flood elevation for the five-hundred-year flood zone. The five-hundred-year flood is calculated by multiplying the elevation of the one-hundred-year BFE by 1.25.

Standards for development in areas of shallow flooding (Zones AO and AH). Located within the special flood hazard areas (SFHA) are areas designated as shallow flooding areas (AO and AH Zones). These areas have flood hazards associated with base flood depths of one foot to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate. In AO and AH Zones, the following provisions apply:

[Added 7-13-2021]

For residential structures, all new construction, substantial improvements and repair to structures that have sustained substantial damage shall have the lowest floor, including basement, elevated to two feet above the depth number specified on the Flood Insurance Rate Map (FIRM) above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated at least three feet above the highest adjacent grade.

For nonresidential structures, all new construction, substantial improvements and repair to structures that have sustained substantial damage shall:

Have the lowest floor, including basement, elevated to two feet above the depth number specified on the Flood Insurance Rate Map (FIRM) above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated at least three feet above the highest adjacent grade; or