Town of Orange, CT Article V Provisions for Flood Hazard Reduction

§ 223-16 General standards.

In all areas of special flood hazard the following provisions are required:

A. New construction and substantial improvements shall be anchored to prevent floatation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

B. New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

C. New construction and substantial improvements shall be constructed by methods and practices that minimize flood damage.

D. Electrical, heating, ventilation, plumbing, 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.

E. New and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.

F. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into floodwaters.

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

H. Manufactured homes:

(1) All manufactured (mobile) homes to be placed, substantially improved, or repaired as a result of substantial damage shall be elevated so that the lowest floor is above the base flood elevation. This includes manufactured homes outside of 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 in an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as a result of a flood.

(2) It 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 floatation, lateral movement, and hydrodynamic and hydrostatic pressures. Anchoring may include, but not be limited to, the use of over-the-top or frame ties to ground anchors.

(3) It shall be installed using methods and practices which minimize flood damage.

(a) Adequate access and drainage should be provided.

(b) Elevation construction standards include the placement of piling foundations no more than 10 feet apart, and reinforcement of piers extending more than six feet above ground level.

(4) Recreational vehicles.

(a) Recreational vehicles placed on sites within all areas of special flood hazard shall either:

[1] Be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use; or

[2] Meet all the general standards of § 223-16A through G and the elevation and anchoring requirement of § 223-16H(1), (2) and (3).

(b) 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.

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

J. A structure already in compliance with the provisions of this chapter shall not be made non-compliant by any alteration, repair, reconstruction or improvement to the structure.

§ 223-17 Specific standards.

A. In all areas of special flood hazard, the following provisions are required:

(1) Residential construction:

(a) New construction of residential structures is prohibited in any one-hundred-year floodplain areas.

(b) Any substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to at least one foot above the base flood elevation.

(2) Non-residential construction: Any new construction or substantial improvement of any commercial, industrial, or non-residential structure located in the area of special flood hazard shall have the lowest floor, including basement, elevated to at least one foot above the level of the base flood elevation.

B. Floodways: Located within areas of special flood hazard established in § 223-7 are areas designated as floodways on the community's Flood Insurance Rate Map or as determined in § 223-15I. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris and potential projectiles and which have erosion potential, encroachments, including fill, new construction, substantial improvements and other developments are prohibited, 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 the proposed encroachments shall not result in any (0.00 feet) increase in flood levels during occurrence of the base flood discharge. Fences in the roadway must be aligned with the flow and be of an open design.

C. 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. 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 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.

D. 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.

§ 223-18 Standards for development in areas of shallow flooding (Zones AO).

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

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

B. For non-residential structures, all new construction, substantial improvements and repair to structures that have sustained substantial damage shall:

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

(2) Together with attendant utility and sanitary facilities, be completely flood-proofed to or above the depth number, in feet, specified on the FIRM above the highest adjacent grade, or if no depth number is specified, at least two feet above the highest adjacent grade, so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Designs for complying with this requirement must be certified by either a Connecticut licensed professional engineer or architect.

C. On-site drainage for all proposed structures in AO Zones located on slopes shall provide adequate drainage paths to guide flood waters around and away from such structures.