DIVISION 3. - FLOOD HAZARD REDUCTION
Part of the Code of Ordinances of Central Falls, RI.
The text
Sec. 10-301. - Development standards.#
The following standards shall apply to any construction or other development located wholly or partly within an area of special flood hazard as defined in section 10-241. Please also refer to the current Rhode Island State Building Code, One and Two Family Dwelling Code, Plumbing Code, Mechanical Code, and Electrical for state standards. The Coastal Resource Management Council (CRMC) may also require special permits for development on the coastal feature. (1)
No watercourse may be altered in a manner which will, in the opinion of the building official or designee, result in any decrease in the capacity of the watercourse, and no land shall be graded or altered in such a manner as to increase the base flood elevation within the city. Where any alteration is permitted, the building official or designee will notify the adjacent communities, the Rhode Island Statewide Planning Program and the Federal Emergency Management Agency.
(2)
In a regulatory floodway, any encroachment is prohibited which would cause any increase in the base flood level unless hydrologic and hydraulic analyses prove that the proposed encroachment would not increase flood levels during the base flood discharge.
(3)
The filling or excavation of land may be permitted only under the following conditions:
a.
Said action will not encroach upon a watercourse.
b.
Said action will not result in an increase in the potential flood level. Where it is determined that said action may result in an increase in the potential flood level, the building official or designee shall require appropriate measures to offset the potential increase. Adequate drainage shall be provided so as to reduce the exposure of the site or any other land to flood hazard.
(4)
No outdoor storage of materials or equipment which is likely to cause damage to property, create a potential obstruction to floodwaters, create a potential fire hazard or pollute the waters during flood periods shall be permitted in any special flood hazard area. Such materials or equipment shall include but not necessarily be limited to: lumber and other buoyant materials, water-soluble materials, volatile or flammable materials, acids or poisons.
(5)
Provision shall be made for anchoring facilities, equipment or yard features which are capable of movement or flotation in floodwaters. Such items shall include but shall not necessarily be limited to: fences, sheds, animal shelters, tanks, storage boxes, planters, vehicles, boats and other items normally positioned or stored on a site outside of a structure.
(6)
The use of flood-resistant materials shall be used for structures within an area of special flood hazard as defined in section 10-241.
(7)
Construction methods and practices shall be used that minimize flood damage.
(8)
Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located to prevent water entry to accumulation.
(9)
Onsite waste disposal systems shall be designed to avoid impairment or contamination of the floodway.
(10)
New and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration.
(11)
Base flood elevation data is required for subdivision proposals or other development greater than 50 lots or five acres.
(12)
In addition to the foregoing, in a V-zone, the following requirements shall apply to any proposed development:
a.
The alteration of sand dunes, where existing, is prohibited.
b.
All new construction shall be located landward of the reach of mean high tide.
(Ord. of 2-27-2009, § 17.07; Ord. of 9-14-2015(2), § 1)
Sec. 10-302. - Specific Standards.#
(a)
Construction standards in special flood hazard areas (SFHA), zones A, A1-30, AE.
(1)
Residential construction. All new construction, substantial improvements, and repair to structures that have sustained substantial damage shall have the bottom of the lowest floor, including basement, elevated to or above the base flood elevation (BFE).
(2)
Nonresidential construction. All new construction, substantial improvements, and repair to structures that have sustained substantial damage which are commercial, industrial or nonresidential structures shall:
a.
Have the bottom of the lowest floor, including basement, elevated to or above the base flood elevation (BFE); or
b.
In lieu of being elevated, nonresidential structures may be dry floodproofed to one 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 state-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 or meeting the provisions of this section. Such certification shall be provided to the building official or designee.
(3)
Fully enclosed areas below the base flood elevation of elevated buildings. All new construction, substantial improvements, or repair of substantial damage to residential or nonresidential structures that include fully enclosed areas formed by a foundation and other exterior walls below the base flood elevation (BFE) of an elevated building, shall be designed to preclude finished living space 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 state-registered professional engineer or architect, or meet the following minimum criteria listed in sections (a)(3)a. to (a)(3)g. below:
a.
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 BFE can be used in the calculation of net area of vents required.
b.
The bottom of all openings shall be no higher than one foot above grade. At least one 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 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.
c.
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. Other coverings may be designed and certified by an engineer or approved by the building official or designee.
d.
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.
e.
All interior walls, floor, and ceiling materials located below the BFE shall be unfinished and resistant to flood damage.
f.
Electrical, plumbing, machinery or other utility equipment that service the structure (furnaces, oil or propane tanks, air conditioners, heat pumps, hot water heaters, ventilation, washers, dryers, electrical junction boxes, circuit breaker boxes and food freezers) are prohibited in the fully enclosed area below the BFE. Utilities or service equipment located in this enclosed area, even if elevated above the BFE in the space, will subject the structure to increased flood insurance rates.
g.
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 this subsection (a)(3). 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. The human intervention necessary to open garage doors when flooding occurs is not an acceptable means of meeting the openings requirements. In addition to the automatic entry of floodwaters, the areas of the garage below BFE must be constructed with flood-resistant materials. Garages attached to nonresidential structures must also meet the aforementioned requirements or be dry floodproofed as per the requirements of subsection (a)(2) of this section.
(4)
Manufactured (mobile) homes and recreational vehicles (RVs).
a.
In all special flood hazard areas (SFHA), any manufactured (mobile) homes to be newly placed, substantially improved or repaired as a result of substantial damage, shall be elevated so that the bottom of the lowest floor is at or above the base flood elevation (BFE). This includes SFHAs 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, or on a site in an existing park which a manufactured home has incurred substantial damage as a result of a flood.
b.
All manufactured (mobile) homes within a 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.
c.
All manufactured (mobile) homes within a SFHA shall be installed using methods and practices which minimize flood damage. Adequate access and drainage should be provided. Elevation construction standards include piling foundations placed no more than ten feet apart, and reinforcement is provided for piers more than six feet above ground level.
d.
Recreational vehicles placed on sites within a SFHA shall either be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use, or be elevated and anchored. 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.
e.
Public utilities and facilities in manufactured (mobile) homes or subdivisions with a SFHA shall be constructed so as to minimize flood damage.
(5)
Accessory structures. Detached accessory structures in zones A, AE, A1-30, AO, and AH (i.e., garages, sheds) do not have to meet the elevation or dry floodproofing requirement if the following standards are met:
a.
The structure is no more than 500 square feet and has a value less than $3,000.00.
b.
The structure has unfinished interiors and must not be used for human habitation. An apartment, office or other finished space over a detached garage is considered human habitation and would require the structure to be elevated.
c.
The structure is used solely for parking of vehicles and/or limited storage.
d.
The accessory structure must be wet floodproofed and designed to allow for the automatic entry and exit of floodwater.
e.
The accessory structure shall be firmly anchored to prevent flotation, collapse and lateral movement.
f.
Service facilities such as electrical, mechanical and heating equipment must be elevated or floodproofed to or above the base flood elevation.
g.
The structure must comply with the floodway encroachment provision in section 10-301(2).
(b)
Additional construction standards in coastal V-zones.
(1)
Residential and nonresidential construction. In V1—30, VE, and V-zones, the elevation of the bottom of the lowest horizontal structural member of the lowers floor of all new and substantially improved structures shall be obtained and maintained. Further, all new construction, substantial improvements:
a.
Shall be elevated and secured to anchored pilings or columns so that the bottom of the lowest horizontal structural member is at or above the base flood elevations (BFE).
b.
Shall be certified by a registered professional engineer/architect that the design and methods of construction meet elevation and anchoring requirements.
c.
Shall have space below the lowest floor either free of obstruction or constructed with breakaway walls. Any enclosed space shall be used solely of building, building access, or storage.
d.
Shall not utilize fill for structural support.
(2)
Manufactured homes. Manufactured homes placed or substantially improved within V1-V30, VE, and V-zones, which meet one of the following criteria, shall meet the V-zones standards.
a.
Outside a manufactured home park or manufactured home subdivision;
b.
In a new manufactured home park or manufactured home subdivision;
c.
In an expansion to an existing manufactured home park or manufactured home subdivision;
d.
On a site in an existing park which a manufactured home has incurred substantial damage as a result of a flood.
In V1—30, VE, and V-zones, manufactured homes shall be placed or substantially improved in an existing manufactured home park to 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 in height above grade and securely anchored.
(3)
Recreational vehicles. In V1—30, VE, and V-zones, all recreational vehicles to be placed on a site must:
a.
Be elevated and anchored;
b.
Be on the site for less than 180 consecutive days; or
c.
Be fully licensed and highway ready.
(Ord. of 2-27-2009, § 17.08; Ord. of 9-14-2015(2), § 1)