(A) Floodplain status standards.
(1) Floodways (riverine). Located within SFHAs, established in § 152.187(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. Under the provisions of the Flood Control Act (I.C. 14-28-1) a permit for construction in a floodway from the Indiana 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 undertaken before the actual start of construction of the structure. General licenses and exemptions to the requirements of the Flood Control Act (I.C. 14-28-1 and 312 IAC 10) may apply to qualified additions/improvements to existing lawful residential structures, rural bridges, logjam removals, wetland restoration, utility line crossings, outfall projects, creek rock removal, and prospecting.
(a) If the site is in a regulatory floodway as established in § 152.187(B), the Floodplain Administrator shall require the applicant to forward the application, along with all pertinent plans and specifications, to the Indiana Department of Natural Resources and apply for approval for construction in a floodway, provided the activity does not qualify for a general license or exemption (I.C. 14-28-1 or 312 IAC 10).
(b) No action shall be taken by the Floodplain Administrator until approval has been granted by the Indiana Department of Natural Resources for construction in the floodway, or evidence provided by an applicant that the development meets specified criteria to qualify for a general license or exemption to the requirement of the Flood Control Act. The floodplain development permit shall meet the provisions contained in this section.
(c) The floodplain development permit cannot be less restrictive than an approval issued for construction in a floodway issued by the Indiana Department of Natural Resources, or the specified criteria used to qualify for a general license or exemption to the Flood Control Act for a specific site/project. However, a community's more restrictive regulations (if any) shall take precedence.
(d) In floodway areas identified on the FIRM, development shall cause no increase in flood levels during the occurrence of the base flood discharge without first obtaining a conditional letter of map revision and meeting requirements of § 152.188(E)(1). A conditional letter of map revision cannot be issued for development that would cause an increase in flood levels affecting a structure and such development should not be permitted.
(e) In floodway areas identified by the Indiana Department of Natural Resources through detailed or approximate studies but not yet identified on the effective FIRM as floodway areas, the total cumulative effect of the proposed development, when combined with all other existing and anticipated development, shall not adversely affect the efficiency of, or unduly restrict the capacity of the floodway. This adverse effect is defined as an increase in the elevation of the regulatory flood of at least 0.15 of a foot as determined by comparing the regulatory flood elevation under the project condition to that under the natural or pre-floodway condition as proven with hydraulic analyses.
(f) For all projects involving channel modifications or fill (including levees) the city shall submit the data and request that the Federal Emergency Management Agency revise the regulatory flood data per mapping standard regulations found at 44 CFR 65.12.
(2) Fringe (riverine). If the site is in the fringe (either identified on the FIRM or identified by the Indiana Department of Natural Resources through detailed or approximate studies and not identified on a FIRM), the Floodplain Administrator may issue the local floodplain development permit provided the provisions contained in this section have been met.
(3) SFHAs without established base flood elevation and/or floodways/fringes (riverine).
(a) Drainage area upstream of the site is greater than one square mile:
1. 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 Indiana Department of Natural Resources for review and comment.
2. No action shall be taken by the Floodplain Administrator until written approval from the Indiana Department of Natural Resources (approval for construction in a floodway, letter of authorization, or evidence of general license
qualification) or a floodplain analysis/regulatory assessment citing the 1% annual chance flood elevation and the recommended flood protection grade has been received from the Indiana Department of Natural Resources.
3. Once the Floodplain Administrator has received the proper written approval, evidence of general license qualification, or floodplain analysis/regulatory assessment approving the proposed development from the Indiana Department of Natural Resources, 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 Indiana Department of Natural Resources and the provisions contained in this section have been met.
(b) Drainage area upstream of the site is less than one square mile:
1. 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.
2. Upon receipt, the Floodplain Administrator may issue the local floodplain development permit, provided the provisions contained in this section have been met.
(4) SFHAs not identified on a map.
(a) If a proposed development site is near a waterway with no SFHA identified on a map, the Floodplain Administrator shall verify the drainage area upstream of the site. If the drainage area upstream of the site is verified as being 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 Indiana Department of Natural Resources for review and comment.
(b) No action shall be taken by the Floodplain Administrator until written approval from the Indiana Department of Natural Resources (approval for construction in a floodway, letter of authorization, or evidence of general license qualification) or a floodplain analysis/regulatory assessment citing the 1% annual chance flood elevation and the recommended flood protection grade has been received from the Indiana Department of Natural Resources.
(c) Once the Floodplain Administrator has received the proper written approval, evidence of general license qualification, or floodplain analysis/regulatory assessment approving the proposed development from the Indiana Department of Natural Resources, 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 Indiana Department of Natural Resources and the provisions contained in this section have been met.
(B) General standards. In all areas of special flood hazard, the following provisions are required:
(1) All new construction, reconstruction or repairs made to a repetitive loss structure, and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
(2) New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage below the FPG.
(3) New construction and substantial improvements must incorporate methods and practices that minimize flood damage.
(4) Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be located at/above the FPG for residential structures. Electrical, heating, ventilation, plumbing, air conditioning equipment, 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 for non-residential structures. Water and sewer pipes, electrical and telephone lines, submersible pumps, and other waterproofed service facilities may be located below the FPG.
(5) New and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(6) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(7) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(8) Any alteration, repair, reconstruction, or improvements to a structure that is in compliance with the provisions of this subchapter shall meet the requirements of new construction as contained in this subchapter.
(9) 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.
(10) Where an existing or proposed structure or other development is affected by multiple flood zones, by multiple base flood elevations, or both, the development activity must comply with the provisions of this subchapter applicable to the most restrictive flood zone and the highest base flood elevation affecting any part of the existing or proposed structure; or for other developments, affecting any part of the area of the development.
(11) Fill projects that do not involve a structure must 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 feet horizontal to one foot vertical.
(C) Specific standards. In all areas of special flood hazard where base flood elevation data or flood depths have been provided, as set forth in § 152.187(B), the following provisions are required:
(1) Building protection requirement. In addition to the general standards described in § 152.189(B), 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 a residential structure.
(b) Construction or placement of a non-residential structure.
(c) Addition or improvement made to an existing structure 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). An addition and/or improvement project that is continuous in scope or time is considered as one project for permitting purposes.
(d) 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 (the costs of any proposed additions or improvements beyond restoring the damaged structure to its before damaged condition must be included in the cost).
(e) Installing a manufactured home on a new site or a new manufactured home on an existing site.
(f) Installing a travel trailer or recreational vehicle on a site for more than 180 days.
(g) Reconstruction or repairs made to a repetitive loss structure.
(h) Addition or improvement made to any existing structure with a previous repair, addition or improvement constructed since the community's first floodplain ordinance.
(2) Residential construction.
(b) In Zone A and Zone AE, new construction or substantial improvement of any residential structure shall have the lowest floor; including basement, at 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 § 152.189(C)(2)(c). Should fill be used to elevate a structure, the standards of § 152.189(C)(2)(d) must be met.
(c) Fully enclosed areas formed by foundation and other exterior walls below the flood protection grade shall meet the following requirement:
1. Designed to preclude finished living space and designed to allow for the automatic entry and exit of floodwaters to equalize hydrostatic flood forces on exterior walls. Flood openings must be designed and installed in compliance with criteria set out in FEMA Technical Bulletin 1. Engineered flood openings must be designed and certified by a registered design professional (requires supporting engineering certification or make/model specific ICC-ES report), or meet the following criteria for non-engineered flood openings:
a. Provide a minimum of two openings on different sides of an enclosure. If there are multiple enclosed areas, each is required to meet the requirements for enclosures, including the requirement for flood openings in exterior walls (having a total net area of not less than one square inch for every one square foot of enclosed area).
b. The bottom of all openings shall be no more than one foot above the higher of the final interior grade (or floor) and the finished exterior grade immediately under each opening.
c. If the floor of the enclosure is below the BFE, the openings must be located wholly below the BFE.
d. If the floor of the enclosure is at or above the BFE, but below the FPG, the openings must be located wholly below the FPG.
e. Doors and windows do not qualify as openings.
f. Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.
2. The floor of such enclosed area must be at or above grade on at least one side.
(d) A residential structure may be constructed on a fill in accordance with the following:
1. 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. The results of the test showing compliance shall be retained in the permit file.
2. Fill shall extend ten feet beyond the foundation of the structure before sloping below the BFE.
3. 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 feet horizontal to one foot vertical.
4. Fill shall not adversely affect the flow of surface drainage from or onto neighboring properties.
5. Fill shall be composed of clean granular or earthen material.
(e) A residential structure may be constructed using a stem wall foundation (also called chain wall, raised-slab-on-grade, and slab-on-stem-wall-with-fill). Any backfilled stem wall foundation (also called chain wall, raised-slab-on-grade, and slab-on-stem-wall-with-fill) must be backfilled with compacted structural fill, concrete, or gravel that supports the floor slab. No flood openings are required for this type of construction.
(3) Non-residential construction.
(b) In Zone A and Zone AE, new construction, or substantial improvement of any commercial, industrial, or non-residential structure (excludes accessory structures) shall either have the lowest floor, including basement and, elevated to or above the FPG 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 § 152.189(C)(3)(c). Should fill be used to elevate a structure, the standards of § 152.189(C)(3)(d) must be met.
(c) Fully enclosed areas formed by foundation and other exterior walls below the flood protection grade shall meet the following requirement:
1. Designed to preclude finished living space and designed to allow for the automatic entry and exit of floodwaters to equalize hydrostatic flood forces on exterior walls. Flood openings must be designed and installed in compliance with criteria set out in FEMA Technical Bulletin 1. Engineered flood openings must be designed and certified by a registered design professional (requires supporting engineering certification or make/model specific ICC-ES report), or meet the following criteria for non-engineered flood openings:
a. Provide a minimum of two openings on different sides of an enclosure. If more than one enclosed area is present, each must have openings on exterior walls (having a total net area of not less than one square inch for every one square foot of enclosed area).
b. The bottom of all openings shall be no more than one foot above the higher of the final interior grade (or floor) and the finished exterior grade immediately under each opening.
c. If the floor of the enclosure is below the BFE, the openings must be located wholly below the BFE.
d. If the floor of the enclosure is at or above the BFE, but below the FPG, the openings must be located wholly below the FPG.
e. Doors and windows do not qualify as openings.
f. Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.
2. The floor of such enclosed area must be at or above grade on at least one side.
(d) A nonresidential structure may be constructed on fill in accordance with the following:
1. 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. The results of the test showing compliance shall be retained in the permit file.
2. Shall extend ten feet beyond the foundation of the structure before sloping below the BFE.
3. 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 feet horizontal to one foot vertical.
4. Shall not adversely affect the flow of surface drainage from or onto neighboring properties.
5. Shall be composed of clean granular or earthen material.
(e) A nonresidential structure may be floodproofed in accordance with the following:
1. 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 Floodplain Administrator.
2. Floodproofing measures shall be operable without human intervention and without an outside source of electricity.
(f) A nonresidential structure may be constructed using a stem wall foundation (also called chain wall, raised-slab-on-grade, and slab-on-stem-wall-with-fill). Any backfilled stem wall foundation must be backfilled with compacted structural fill, concrete, or gravel that supports the floor slab. No flood openings are required for this type of construction.
(4) Manufactured homes and recreational vehicles.
(a) These requirements apply to all manufactured homes to be placed on a site in the SFHA:
1. 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.
2. Fully enclosed areas formed by foundation and other exterior walls below the FPG 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 § 152.189(C)(2)(c).
3. Flexible skirting and rigid skirting not attached to the frame or foundation of a manufactured home are not required to have openings.
(b) Recreational vehicles placed on a site in the SFHA shall either:
1. Be on site for less than 180 days and be fully licensed and ready for use on a public highway (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
2. Meet the requirements for manufactured homes as stated earlier in this section.
(5) Accessory structures. Within SFHAs, new construction or placement of an accessory structure must meet the following standards:
(a) Shall have a floor area of 400 square feet or less.
(b) Use shall be limited to parking of vehicles and limited storage.
(c) Shall not be used for human habitation.
(d) Shall be constructed of flood resistant materials.
(e) Shall be constructed and placed on the lot to offer the minimum resistance to the flow of floodwaters.
(f) Shall be firmly anchored to prevent flotation.
(g) Service facilities such as electrical and heating equipment shall be elevated or floodproofed to or above the FPG.
(h) Shall be 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 § 152.189(C)(3)(c).
(i) Shall not have subsequent additions or improvements that would preclude the structure from its continued designation as an accessory structure.
(6) Free-standing pavilions, gazebos, decks, carports, and similar development. Within SFHAs, new construction or placement of free-standing pavilions, gazebos, decks, carports, and similar development must meet the following standards:
(a) Shall have open sides (having not more than one rigid wall).
(b) Shall be anchored to prevent flotation or lateral movement.
(c) Shall be constructed of flood resistant materials below the FPG.
(d) Any electrical, heating, plumbing and other service facilities shall be located at/above the FPG.
(e) Shall not have subsequent additions or improvements that would preclude the development from its continued designation as a free-standing pavilion, gazebo, carport, or similar open-sided development.
(7) Above ground gas or liquid storage tanks. Within SFHAs, all newly placed aboveground gas or liquid storage tanks shall meet the requirements for a non-residential structure as required in § 152.189
(C)(3).
(D) Standards for subdivision and other new developments.
(1) All subdivision proposals and all other proposed new development shall be consistent with the need to minimize flood damage.
(2) All subdivision proposals and all other proposed new development 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 and all other proposed new development shall have adequate drainage provided to reduce exposure to flood hazards.
(4) In all areas of special flood hazard where base flood elevation data are not available, the applicant shall provide a hydrologic and hydraulic engineering analysis that generates base flood elevations for all subdivision proposals and all other proposed new development (including manufactured home parks and subdivisions), which is greater than the lesser of 50 lots or five acres, whichever is less.
(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).
(7) Streets, blocks lots, parks and other public grounds shall be located and laid out in such a manner as to preserve and utilize natural streams and channels. Wherever possible the floodplains shall be included within parks or other public grounds.
(E) Standards for critical facilities. 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.
(Ord. 466, §§ 3-6-1, 3-7-1, 3-8-1, passed 5-11-98; Am. Ord. 608, passed 9-13-10; Am. Ord. 763, passed 8-14-23) Penalty, see § 152.999