(A) General standards. In all SFHAs and known floodprone areas, the following provisions are required.
(1) New construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.
(2) Manufactured homes shall be anchored to prevent 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 standard shall be in addition to and consistent with applicable state requirements for resisting wind forces.
(3) New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage below the FPG.
(4) New construction and substantial improvements shall be constructed by methods and practices that minimize flood damage.
(5) Electrical, heating, ventilation, plumbing, air conditioning equipment, utility meters and other service facilities shall be located at/above the FPG or designed so as to prevent water from entering or accumulating within the components below the FPG. Water and sewer pipes, electrical and telephone lines, submersible pumps and other waterproofed service facilities may be located below the FPG.
(6) New and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
(7) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
(8) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(9) Any alteration, repair, reconstruction or improvements to a structure that is in compliance with the provisions of this chapter shall meet the requirements of “new construction” as contained in this chapter.
(10) Any alteration, repair, reconstruction or improvement to a structure that is not in compliance with the provisions of this chapter shall be undertaken only if said nonconformity is not further extended or replaced.
(11) Whenever any portion of the SFHA is authorized for use, the volume of space which will be occupied by the authorized fill or structure below the BFE shall be compensated for and balanced by an equivalent volume of excavation taken below the BFE. The excavation volume shall be at least equal to the volume of storage lost (replacement ratio of one to one) due to the fill or structure.
(a) The excavation shall take place in the floodplain and in the same property in which the authorized fill or structure is located.
(b) Under certain circumstances, the excavation may be allowed to take place outside of but adjacent to the floodplain provided that the excavated volume will be below the regulatory flood elevation, will be in the same property in which the authorized fill or structure is located, will be accessible to the regulatory floodwater, will not be subject to ponding when not inundated by floodwater, and that it shall not be refilled.
(c) The excavation shall provide for true storage of floodwater but shall not be subject to ponding when not inundated by floodwater.
(d) The fill or structure shall not obstruct a drainage way leading to the floodplain.
(e) The grading around the excavation shall be such that the excavated area is accessible to the regulatory floodwater.
(f) The fill or structure shall be of a material deemed stable enough to remain firm and in place during periods of flooding and shall include provisions to protect adjacent property owners against any increased runoff or drainage resulting from its placement.
(g) Plans depicting the areas to be excavated and filled shall be submitted prior to the actual start of construction or any site work; once site work is complete, but before the actual start of construction, the applicant shall provide to the Floodplain Administrator a certified survey of the excavation and fill sites demonstrating the fill and excavation comply with this section.
(B) Specific standards. In all SFHAs, the following provisions are required.
(1) Generally. In addition to the requirements of division (A) above, all structures to be located in the SFHA shall be protected from flood damage below the FPG. This building protection requirement applies to the following situations:
(a) Construction or placement of any new structure having a floor area greater than 400 square feet;
(b) Addition or improvement made to any existing structure:
1. Where the cost of the addition or improvement equals or exceeds 50% of the value of the existing structure (excluding the value of the land); or
2. With a previous addition or improvement constructed since the community’s first floodplain ordinance.
(c) Reconstruction or repairs made to a damaged structure where the costs of restoring the structure to its before damaged condition equals or exceeds 50% of the market value of the structure (excluding the value of the land) before damage occurred;
(d) Installing a travel trailer or recreational vehicle on a site for more than 180 days;
(e) Installing a manufactured home on a new site or a new manufactured home on an existing site. This chapter does not apply to returning the existing manufactured home to the same site it lawfully occupied before it was removed to avoid flood damage; and
(f) Reconstruction or repairs made to a repetitive loss structure.
(2) Residential construction. New construction or substantial improvement of any residential structure (or manufactured home) shall have the lowest floor; including basement, at or above the FPG (two feet above the base flood elevation). Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with the standards of division (B)(4) below.
(3) Nonresidential construction. New construction or substantial improvement of any commercial, industrial or nonresidential structure (or manufactured home) shall either have the lowest floor, including basement, elevated to or above the FPG (two feet above the base flood elevation) or be floodproofed to or above the FPG. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with the standards of division (B)(4) below. Structures located in all A Zones may be floodproofed in lieu of being elevated if done in accordance with the following:
(a) A registered professional engineer or architect shall certify that the structure has been designed so that below the FPG, the structure and attendant utility facilities are watertight and capable of resisting the effects of the regulatory flood. The structure design shall take into account flood velocities, duration, rate of rise, hydrostatic pressures and impacts from debris or ice. Such certification shall be provided to the official as set forth in § 154.04(C)(2)(k).
(b) Floodproofing measures shall be operable without human intervention and without an outside source of electricity.
(4) Elevated structures.
(a) New construction or substantial improvements of elevated structures shall have the lowest floor at or above the FPG.
(b) Elevated structures with fully enclosed areas formed by foundation and other exterior walls below the flood protection grade shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls.
(c) Designs must meet the following minimum criteria.
1. Provide a minimum of two openings located in a minimum of two exterior walls (having a total net area of not less than one square inch for every one square foot of enclosed area).
2. The bottom of all openings shall be no more than one foot above the exterior grade or the interior grade immediately beneath each opening, whichever is higher.
3. Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.
4. Openings are to be not less than three inches in any direction in the plane of the wall. This requirement applies to the hole in the wall, excluding any device that may be inserted such as typical foundation air vent device.
5. Access to the enclosed area shall be the minimum necessary to allow for parking for 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).
6. The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.
7. The interior grade of such enclosed area shall be at an elevation at or higher than the exterior grade.
8. Where elevation requirements exceed six feet above the highest adjacent grade, a copy of the legally recorded deed restriction prohibiting the conversion of the area below the lowest floor to a use or dimension contrary to the structure’s originally approved design, shall be presented as a condition of issuance of the final certificate of occupancy.
(5) Structures constructed on fill. A residential or nonresidential structure may be constructed on a permanent land fill in accordance with the following.
(a) The fill shall be placed in layers no greater than one foot deep before compacting to 95% of the maximum density obtainable with either the Standard or Modified Proctor Test method.
(b) The fill should extend at least ten feet beyond the foundation of the structure before sloping below the FPG.
(c) The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap or bulk heading. If vegetative cover is used, the slopes shall be no steeper than three horizontal to one vertical.
(d) The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties.
(e) The top of the lowest floor including basements shall be at or above the FPG.
(6) Standards for manufactured homes and recreational vehicles. Manufactured homes and recreational vehicles to be installed or substantially improved on a site for more than 180 days must meet one of the following requirements:
(a) The manufactured home shall be elevated on a permanent foundation such that the lowest floor shall be at or above the FPG and securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. This requirement applies to all manufactured homes to be placed on a site;
1. Outside a manufactured home park or subdivision;
2. In a new manufactured home park or subdivision;
3. In an expansion to an existing manufactured home park or subdivision; or
4. In an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood.
(b) The manufactured home shall be elevated so that the lowest floor of the manufactured home chassis is supported by reinforced piers or other foundation elevations that are no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. This requirement applies to all manufactured homes to be placed on a site in an existing manufactured home park or subdivision that has not been substantially damaged by a flood.
(c) Manufactured homes with fully enclosed areas formed by foundation and other exterior walls below the flood protection grade shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls as required for elevated structures in division (B)(4) above.
(d) Flexible skirting and rigid skirting not attached to the frame or foundation of a manufactured home are not required to have openings.
(e) Recreational vehicles placed on a site shall either:
1. Be on site for less than 180 days; and
2. Be fully licensed and ready for highway use (defined as being 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); or
3. Meet the requirements for “manufactured homes” as stated earlier in this section.
(C) Standards for subdivision proposals.
(1) All subdivision proposals shall be consistent with the need to minimize flood damage.
(2) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.
(3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards.
(4) Base flood elevation data shall be provided for subdivision proposals and other proposed development (including manufactured home parks and subdivisions), which is greater than the lesser of 50 lots or five acres.
(5) All subdivision proposals shall minimize development in the SFHA and/or limit density of development permitted in the SFHA.
(6) All subdivision proposals shall ensure safe access into/out of SFHA for pedestrians and vehicles (especially emergency responders).
(D) Critical facility. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the SFHA. Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated to or above the FPG at the site. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes elevated to or above the FPG shall be provided to all critical facilities to the extent possible.
(E) Standards for identified floodways.
(1) Located within SFHAs, established in § 154.03(B), are areas designated as floodways. The floodway is an extremely hazardous area due to the velocity of floodwaters, which carry debris, potential projectiles and has erosion potential. If the site is in an identified floodway, the Floodplain Administrator shall require the applicant to forward the application, along with all pertinent plans and specifications, to the State Department of Natural Resources and apply for a permit for construction in a floodway. Under the provisions of I.C. 14-28-1, a permit for construction in a floodway from the State Department of Natural Resources is required prior to the issuance of a local building permit for any excavation, deposit, construction or obstruction activity located in the floodway. This includes land preparation activities such as filling, grading, clearing and paving and the like undertaken before the actual start of construction of the structure; however, it does exclude non-substantial additions/improvements to existing (lawful) residences in a non-boundary river floodway. (I.C. 14-28-1-26 allows construction of non-substantial additions/improvements to residences in a non-boundary river floodway without obtaining a permit for construction in the floodway from the State Department of Natural Resources. Please note that if fill is needed to elevate an addition above the existing grade, prior approval (construction in a floodway permit) for the fill is required from the State Department of Natural Resources.)
(2) No action shall be taken by the Floodplain Administrator until a permit (when applicable) has been issued by the State Department of Natural Resources granting approval for construction in the floodway. Once a permit for construction in a floodway has been issued by the State Department of Natural Resources, the Floodplain Administrator may issue the local floodplain development permit, provided the provisions contained in this section have been met. The floodplain development permit cannot be less restrictive than the permit for construction in a floodway issued by the State Department of Natural Resources; however, a community’s more restrictive regulations (if any) shall take precedence.
(3) No development shall be allowed which acting alone or in combination with existing or future development, will increase the regulatory flood more than 0.14 of one foot.
(4) For all projects involving channel modifications or fill (including levees) the town shall submit the data and request that the Federal Emergency Management Agency revise the regulatory flood data.
(F) Standards for identified fringe. If the site is located in an identified fringe, then the Floodplain Administrator may issue the local floodplain development permit provided the provisions contained in § 154.05 have been met. The key provision is that the top of the lowest floor of any new or substantially improved structure shall be at or above the FPG.
(G) Standards for SFHAs without established base flood elevation and/or floodways/fringes.
(1) Drainage area upstream of the site is greater than one square mile.
(a) If the site is in an identified floodplain where the limits of the floodway and fringe have not yet been determined, and the drainage area upstream of the site is greater than one square mile, the Floodplain Administrator shall require the applicant to forward the application, along with all pertinent plans and specifications, to the State Department of Natural Resources for review and comment.
(b) No action shall be taken by the Floodplain Administrator until either a permit for construction in a floodway or a floodplain analysis/regulatory assessment citing the 1% annual chance flood elevation and the recommended flood protection grade has been received from the State Department of Natural Resources.
(c) Once the Floodplain Administrator has received the proper permit for construction in a floodway or floodplain analysis/regulatory assessment approving the proposed development, a floodplain development permit may be issued provided the conditions of the floodplain development permit are not less restrictive than the conditions received from the State Department of Natural Resources and the provisions contained in this section have been met.
(2) Drainage area upstream of the site is less than one square mile.
(a) If the site is in an identified floodplain where the limits of the floodway and fringe have not yet been determined and the drainage area upstream of the site is less than one square mile, the Floodplain Administrator shall require the applicant to provide an engineering analysis showing the limits of the floodplain and 1% annual chance flood elevation for the site.
(b) Upon receipt, the Floodplain Administrator may issue the local Floodplain Development Permit, provided the provisions contained in this section have been met.
(3) The total cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the regulatory flood more than 0.14 of one foot and will not increase flood damages or potential flood damages.
(H) Standards for floodprone areas. All development in known floodprone areas not identified on FEMA maps, or where no FEMA published map is available, shall meet applicable standards as required per § 154.05.
(Prior Code, § 92.05)