(a) Statutory Authorization. ARTICLE XVIII, Section 3, of the Ohio Constitution grants municipalities the legal authority to adopt land use and control measures for promoting the health, safety, and general welfare of its citizens.
(b) Findings of Fact. The City has special flood hazard areas that are subject to periodic inundation which may result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base. Additionally, structures that are inadequately elevated, floodproofed, or otherwise protected from flood damage also contribute to the flood loss. These regulations are intended to minimize the threat of such damages and to achieve the purposes hereinafter set forth.
(c) Statement of Purpose. It is the purpose of these regulations to promote the public health, safety and general welfare, and to:
(1) Protect human life and health;
(2) Minimize expenditure of public money for costly flood control projects;
(3) Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
(4) Minimize prolonged business interruptions;
(5) Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard;
(6) Help maintain a stable tax base by providing for the proper use and development of areas of special flood hazard so as to protect property and minimize future flood blight areas;
(7) Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions;
(8) Minimize the impact of development on adjacent properties within and near flood prone areas;
(9) Ensure that the flood storage and conveyance functions of the floodplain are maintained;
(10) Minimize the impact of development on the natural, beneficial values of the floodplain;
(11) Prevent floodplain uses that are either hazardous or environmentally incompatible; and
(12) Meet community participation requirements of the National Flood Insurance Program.
(d) Methods of Reducing Flood Loss. In order to accomplish its purposes, these regulations include methods and provisions for:
(1) Restricting or prohibiting uses which are dangerous to health, safety, and property due to water hazards, or which result in damaging increases in flood heights or velocities;
(2) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
(3) Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel flood waters;
(4) Controlling filling, grading, dredging, excavating, and other development which may increase flood damage; and,
(5) Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas.
(e) Lands to Which These Regulations Apply. These regulations shall apply to all special flood hazard areas within the jurisdiction of the City as identified in Section 1125.01(f) of these Subdivision Regulations, including any additional areas of special flood hazard annexed by the City
(f) Basis for Establishing the Areas of Special Flood Hazard. For the purposes of these regulations, the following studies and/or maps are hereby adopted by reference and made a part of this Section:
(1) Flood Insurance Study Miami County, Ohio and Incorporated Areas and Flood Insurance Rate map Miami County, Ohio and Incorporated Areas both effective Augusts 2, 2011, or its latest edition.
(2) Other studies and/or maps which may be relied upon for establishment of the flood protection elevation, delineation of the 100-year floodplain, floodways or delineation of other areas of special flood hazard.
(3) Any hydrologic and hydraulic engineering analysis authored by an Ohio registered Professional Engineer, which then has been approved by the Floodplain Administrator as required by Section 1125.04(c) of these Subdivision Regulations.
(4) Any revisions to the aforementioned maps and/or studies, including any Letter of Map Change issued by FEMA, are hereby adopted by reference and declared to be a part of this Section.
(5) Any flood easement owned by, or dedicated by plat or deed to, the City, Concord Township, Staunton Township, Miami County, the State of Ohio, and/or the Miami Conservancy District.
(6) Any Floodplain Overlay District identified on the City Zoning Map.
(7) Such maps and/or studies are on file at the City of Troy, City Hall, 100 South Market Street, Troy, Ohio.
(g) Abrogation and Greater Restrictions. These regulations are not intended to repeal any existing ordinances including subdivision regulations, zoning or building codes. In the event of a conflict between these regulations and any other ordinance, the more restrictive shall be followed. These regulations shall not impair any deed restriction covenant or easement but the land subject to such interests shall also be governed by the regulations.
(h) Interpretation. In the interpretation and application of these regulations, all provisions shall be:
(2) Considered as minimum requirements;
(3) Liberally construed in favor of the governing body; and,
(4) Deemed neither to limit nor repeal any other powers granted under state statutes. Where a provision of these regulations may be in conflict with a state or Federal law, such state or Federal law shall take precedence over these regulations.
(i) Warning and Disclaimer of Liability. The degree of flood protection required by these regulations is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man made or natural causes. These regulations do not imply that land outside the areas of special flood hazard or uses permitted within such areas will be free from flooding or flood damage. These regulations shall not create liability on the part of the City, any officer or employee thereof, or the Federal Emergency Management Agency, for any flood damage that results from reliance on these regulations or any administrative decision lawfully made thereunder.
(j) Severability. Should any section or provision of these regulations be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the regulations as a whole, or any part thereof other than the part so declared to be unconstitutional or invalid. (Ord. 73-2021. Passed 1-18-22.)
(a) Designation of the Floodplain Administrator. The City Engineer is hereby appointed to administer and implement these regulations and is referred to herein as the Floodplain Administrator.
(b) Duties and Responsibilities of the Floodplain Administrator. The duties and responsibilities of the Floodplain Administrator shall include but are not limited to:
(1) Evaluate applications for permits to develop in special flood hazard areas.
(2) Interpret floodplain boundaries and provide flood hazard and flood protection elevation information.
(3) Issue permits to develop in special flood hazard areas when the provisions of these regulations have been met, or refuse to issue the same in the event of noncompliance.
(4) Inspect buildings and lands to determine whether any violations of these regulations have been committed.
(5) Make and permanently keep all records for public inspection necessary for the administration of these regulations including Flood Insurance Rate Maps, Letters of Map Amendment and Revision, records of issuance and denial of permits to develop in special flood hazard areas, determinations of whether development is in or out of special flood hazard areas for the purpose of issuing floodplain development permits, elevation certificates, variances, and records of enforcement actions taken for violations of these regulations.
(6) Enforce the provisions of these regulations.
(7) Provide information, testimony, or other evidence as needed during variance hearings.
(8) Coordinate map maintenance activities and FEMA follow-up.
(9) Conduct substantial damage determinations to determine whether existing structures, damaged from any source and in special flood hazard areas identified by FEMA, must meet the development standards of these regulations.
(c) Floodplain Development Permits. It shall be unlawful for any person to begin construction or other development activity including but not limited to filling; grading; construction; alteration, remodeling, or expanding any structure; or alteration of any watercourse wholly within, partially within or in contact with any identified special flood hazard area, as established in Section 1125.01(f) of these Subdivision Regulations, until a floodplain development permit is obtained from the Floodplain Administrator. Such floodplain development permit shall show that the proposed development activity is in conformity with the provisions of these regulations. No such permit shall be issued by the Floodplain Administrator until the requirements of these regulations have been met.
(d) Application Required. An application for a floodplain development permit shall be required for all development activities located wholly within, partially within, or in contact with an identified special flood hazard area. Such application shall be made by the owner of the property or his/her authorized agent, herein referred to as the applicant, prior to the actual commencement of such construction on a form furnished for that purpose. Where it is unclear whether a development site is in a special flood hazard area, the Floodplain Administrator may require an application for a floodplain development permit to determine the development's location. Such applications shall include, but not be limited to:
(1) Site plans drawn to scale showing the nature, location, dimensions, and topography of the area in question; the location of existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing.
(2) Elevation of the existing, natural ground where structures are proposed.
(3) Elevation of the lowest floor, including basement, of all proposed structures.
(4) Such other material and information as may be requested by the Floodplain Administrator to determine conformance with, and provide enforcement of these regulations.
(5) Technical analyses conducted by the appropriate design professional registered in the State of Ohio and submitted with an application for a floodplain development permit when applicable:
A. Floodproofing certification for non-residential floodproofed structure as required in Section 1125.03(e) of these Subdivision Regulations.
B. Certification that fully enclosed areas below the lowest floor of a structure not meeting the design requirements of Section 1125.03(d)(5) of these Subdivision Regulations are designed to automatically equalize hydrostatic flood forces.
C. Description of any watercourse alteration or relocation that the flood carrying capacity of the watercourse will not be diminished, and maintenance assurances as required in Section 1125.03(i)(3) of these Subdivision Regulations.
D. A hydrologic and hydraulic analysis demonstrating that the cumulative effect of proposed development, when combined with all other existing and anticipated development will not increase the water surface elevation of the base flood by more than one (1) foot in special flood hazard areas where the Federal Emergency Management Agency has provided base flood elevations but no floodway as required by Section 1125.03(i)(2) of these Subdivision Regulations.
E. A hydrologic and hydraulic engineering analysis showing impact of any development on flood heights in an identified floodway as required by Section 1125.03(i)(1) of these Subdivision Regulations.
F. Generation of base flood elevation(s) for subdivision and large scale developments as required by Section 1125.03(c) of these Subdivision Regulations.
G. Volumetric calculations demonstrating compensatory storage have been provided as required by Section 1125.03(i)(4) of these Subdivision Regulations.
(6) The application fee for a Floodplain Development Permit shall be as listed in the Schedule of Fees adopted by the City.
(e) Review and Approval of a Floodplain Development Permit Application.
(1) Review.
A. After receipt of a complete application, the Floodplain Administrator shall review the application to ensure that the standards of these regulations have been met. No floodplain development permit application shall be reviewed until all information required in Section 1125.02(d) of these Subdivision Regulations has been received by the Floodplain Administrator.
B. The Floodplain Administrator shall review all floodplain development permit applications to assure that all necessary permits have been received from those federal, state or local governmental agencies from which prior approval is required. The applicant shall be responsible for obtaining such permits as required including permits issued by the U.S. Army Corps of Engineers under Section 10 of the Rivers and Harbors Act and Section 404 of the Clean Water Act, and the Ohio Environmental Protection Agency under Section 401 of the Clean Water Act.
(2) Approval. Within thirty (30) days after the receipt of a complete application, the Floodplain Administrator shall either approve or disapprove the application. If an application is approved, a floodplain development permit shall be issued. All floodplain development permits shall be conditional upon the commencement of work within one (1) year. A floodplain development permit shall expire one (1) year after issuance unless the permitted activity has been substantially begun and is thereafter pursued to completion.
(f) Inspections. The Floodplain Administrator shall make periodic inspections at appropriate times throughout the period of construction in order to monitor compliance with permit conditions.
(g) Post-Construction Certifications Required. The following as-built certifications are required after a floodplain development permit has been issued:
(1) For new or substantially improved residential structures, or nonresidential structures that have been elevated, the applicant shall have a Federal Emergency Management Agency Elevation Certificate completed by a registered surveyor to record as-built elevation data. For elevated structures in Zone A and Zone AO areas without a base flood elevation, the elevation certificate may be completed by the property owner or owner's representative.
(2) For all development activities subject to the standards of Section 1125.02(j) (1) of these Subdivision Regulations, a Letter of Map Revision.
(h) Revoking a Floodplain Development Permit. A floodplain development permit shall be revocable, if among other things, the actual development activity does not conform to the terms of the application and permit granted thereon. In the event of the revocation of a permit, an appeal may be taken to the Appeals Board in accordance with Section 1125.04 of these Subdivision Regulations of these regulations.
(i) Exemption from Filing a Development Permit. An application for a floodplain development permit shall not be required for:
(1) Maintenance work such as roofing, painting, and basement sealing, or for small nonstructural development activities (except for filling and grading) valued at less than five thousand dollars ($5,000).
(2) Development activities in an existing or proposed manufactured home park that are under the authority of the Ohio Department of Health and subject to the flood damage reduction provisions of the O.A.C. Chapter 3701.
(3) Major utility facilities permitted by the Ohio Power Siting Board under Ohio R.C. Chapter 4906.
(4) Hazardous waste disposal facilities permitted by the Hazardous Waste Siting Board under Ohio R.C. Chapter 3734.
(5) Development activities undertaken by a federal agency and which are subject to Federal Executive Order 11988 - Floodplain Management.
(6) Any proposed action exempt from filing for a floodplain development permit is also exempt from the standards of these regulations.
(j) Map Maintenance Activities. To meet National Flood Insurance Program minimum requirements to have flood data reviewed and approved by FEMA, and to ensure that the City and Miami County flood maps, studies and other data identified in Section 1125.01 (f) of these Subdivision Regulations accurately represent flooding conditions so appropriate floodplain management criteria are based on current data, the following map maintenance activities are identified:
(1) Requirement to Submit New Technical Data.
A. For all development proposals that impact floodway delineations or base flood elevations, the Floodplain Administrator shall ensure that technical data reflecting such changes be submitted to FEMA within six months of the date such information becomes available. These development proposals include:
1. Floodway encroachments that increase or decrease base flood elevations or alter floodway boundaries;
2. Fill sites to be used for the placement of proposed structures where the applicant desires to remove the site from the special flood hazard area;
3. Alteration of watercourses that result in a relocation or elimination of the special flood hazard area, including the placement of culverts; and
4. Subdivision or large scale development proposals requiring the establishment of base flood elevations in accordance with Section 1125.03 (c) of these Subdivision Regulations.
B. It is the responsibility of the applicant to have technical data, required in accordance with Section 1125.02 (j) (1) of these Subdivision Regulations, prepared in a format required for a Conditional Letter of Map Revision or Letter of Map Revision, and submitted to FEMA. Submittal and processing fees for these map revisions shall be the responsibility of the applicant.
C. The Floodplain Administrator shall require a Conditional Letter of Map Revision prior to the issuance of a floodplain development permit for:
1. Proposed floodway encroachments that increase the base flood elevation; and
2. Proposed development which increases the base flood elevation by more than one (1) foot in areas where FEMA has provided base flood elevations but no floodway.
D. Floodplain development permits issued by the Floodplain Administrator shall be conditioned upon the applicant obtaining a Letter of Map Revision from FEMA for any development proposal subject to Section 1125.02(j)(1)A. of these Subdivision Regulations.
(2) Right to Submit New Technical Data. The Floodplain Administrator may request changes to any of the information shown on an effective FIRM that does not impact floodplain or floodway delineations or base flood elevations, such as labeling or planimetric details. Such a submission shall include appropriate supporting documentation made in writing and signed by the Mayor of the City and may be submitted at any time.
(3) Annexation / Detachment. Within two years after an occurrence, the Floodplain Administrator shall notify FEMA in writing when the boundaries of the City have been modified by annexation or the community has assumed authority over an area, or no longer has authority to adopt and enforce floodplain management regulations for a particular area. In order that future FIRMs accurately represent boundaries, the Floodplain Administrator shall include within such notification a copy of a map of the City suitable for reproduction, clearly showing the new corporate limits or the new area for which the City has assumed or relinquished floodplain management regulatory authority.
(k) Data Use and Flood Map Interpretation. The following guidelines shall apply to the use and interpretation of maps and other data showing areas of special flood hazard:
(1) In areas where FEMA has not identified special flood hazard areas, or in FEMA identified special flood hazard areas where base flood elevation and floodway data have not been identified, the Floodplain Administrator shall review and reasonably utilize any other flood hazard data available from a federal, state, or other source.
(2) Base flood elevations and floodway boundaries produced on FEMA flood maps and studies shall take precedence over base flood elevations and floodway boundaries by any other source that reflect a reduced floodway width and/or lower base flood elevations. Other sources of data, showing increased base flood elevations and/or larger floodway areas than are shown on FEMA flood maps and studies, shall be reasonably used by the Floodplain Administrator.
(3) When Preliminary Flood Insurance Rate Maps and/ or Flood Insurance Study have been provided by FEMA:
A. Upon the issuance of a Letter of Final Determination by the FEMA, the preliminary flood hazard data shall be used and replace all previously existing flood hazard data provided from FEMA for the purposes of administering these regulations.
B. Prior to the issuance of a Letter of Final Determination by FEMA, the use of preliminary flood hazard data shall only be required where no base flood elevations and /or floodway areas exist or where the preliminary base flood elevations or floodway area exceed the base flood elevations and/or floodway widths in existing flood hazard data provided from FEMA. Such preliminary data may be subject to change and / or appeal to FEMA.
(4) The Floodplain Administrator shall make interpretations, where needed, as to the exact location of the flood boundaries and areas of special flood hazard. A person contesting the determination of the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Section 1125.04, Appeals and Variances.
(5) Where a map boundary showing an area of special flood hazard and field elevations disagree, the base flood elevations or flood protection elevations (as found on an elevation profile, floodway data table, established high water marks, etc.) shall prevail.
(l) Substantial Damage Determinations. Damages to structures may result from a variety of causes including flood, tornado, wind, heavy snow, fire, etc. After such a damage event, the Floodplain Administrator shall:
(1) Determine whether damaged structures are located in special flood hazard areas;
(2) Conduct substantial damage determinations for damaged structures located in special flood hazard areas; and
(3) Make reasonable attempt to notify owners of substantially damaged structures of the need to obtain a floodplain development permit prior to repair, rehabilitation, or reconstruction.
Additionally, the Floodplain Administrator may implement other measures to assist with the substantial damage determination and subsequent repair process. These measures include issuing press releases, public service announcements, and other public information materials related to the floodplain development permits and repair of damaged structures; coordinating with other federal, state, and local agencies to assist with substantial damage determinations; providing owners of damaged structures materials and other information related to the proper repair of damaged structures in special flood hazard areas; and assist owners of substantially damaged structures with Increased Cost of Compliance insurance claims.
(Ord. 73-2021. Passed 1-18-22.)
(a) Use Regulations.
(1) Permitted Uses. All uses not otherwise prohibited in this section or any other applicable land use regulation adopted by the City may be permitted, provided they meet the provisions of these regulations.
(2) Prohibited Uses. The following uses are prohibited in any special flood hazard area:
A. Private water supply systems regulated under Section 3701 of the Ohio R.C.
B. Infectious waste treatment facilities regulated under Section 3734 of the Ohio R.C.
C. Storage of explosives.
D. Storage of material or equipment that, in time of flooding, could become buoyant and therefore pose an obstruction to floodwater flow in identified floodway areas.
E. New construction of any residential or nonresidential structures in the floodway portion of any special flood hazard area.
(b) Water and Wastewater Systems. The following standards apply to all water supply, sanitary sewerage and waste disposal systems not otherwise regulated by the Ohio R.C.:
(1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the systems;
(2) New and replacement sanitary sewerage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and,
(3) On-site waste disposal systems shall be located to avoid impairment to or contamination from them during flooding.
(c) Subdivisions and Large Developments.
(1) All subdivision proposals shall be consistent with the need to minimize flood damage and are subject to all applicable standards in these regulations;
(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 damage; and
(4) For all subdivision proposals and other proposed developments containing fifty (50) or more lots or five (5) or more acres, the applicant shall provide a hydrologic and hydraulic engineering analysis that generates base flood elevations for any areas of special flood hazard.
(d) Residential Structures.
(1) New construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Where a structure, including its foundation members, is elevated on fill to or above the base flood elevation, the requirements for anchoring in Section 1125.03 (d) (1) of these Subdivision Regulations and for construction materials resistant to flood damage in Section 1125.03 (d) (2) of these Subdivision Regulations shall be considered to have been satisfied.
(2) New construction and substantial improvements shall be constructed with methods and materials resistant to flood damage.
(3) New construction and substantial improvements shall be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or elevated so as to prevent water from entering or accumulating within the components during conditions of flooding.
(4) New construction and substantial improvement of any residential structure, including manufactured homes, shall have the lowest floor, including basement, elevated to or above the flood protection elevation. Where flood protection elevation data are not available the structure shall have the lowest floor, including basement, elevated at least two feet above the highest adjacent natural grade. Support structures and other foundation members shall be certified by a registered professional engineer or registered architect to have been designed and constructed in accordance with ASCE 24, Flood Resistant Design and Construction.
(5) New construction and substantial improvements, including manufactured homes, that do not have basements and that are elevated to the flood protection elevation using pilings, columns, posts, or solid foundation perimeter walls with openings sufficient to allow unimpeded movement of flood waters may have an enclosure below the lowest floor provided the enclosure meets the following standards:
A. Be used only for the parking of vehicles, building access, or storage; and
B. Be designed and certified by a registered professional engineer or architect to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters; or
C. Have a minimum of two openings on different walls having a total net area not less than one square inch for every square foot of enclosed area, and the bottom of all such openings being no higher than one (1) foot above grade. The openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(6) Manufactured homes shall be affixed to a permanent foundation and anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Methods of anchoring may include, but are not limited to, use of over the top or frame ties to ground anchors.
(7) Repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as a historic structure and is the minimum necessary to preserve the historic character and design of the structure, shall be exempt from the development standards of Section 1125.03(d) of these Subdivision Regulations.
(8) Where flood protection elevation data are not available, new construction and substantial improvement shall have adequate drainage paths around structures on slopes to guide floodwaters around and away from the structure.
(9) Each new residential site shall have direct access to a walkway, driveway, or roadway whose surface elevation is not less than the flood protection elevation and such escape route shall lead directly out of the floodplain area.
(e) Nonresidential Structures.
(1) New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet the requirements of Section 1125.03 (d) (1)-(3) and (5)-(9) of these Subdivision Regulations.
(2) New construction and substantial improvement of any commercial, industrial or other non-residential structure shall either have the lowest floor, including basement, elevated to or above the level of the flood protection elevation; or, together with attendant utility and sanitary facilities, shall meet all of the following standards:
A. Be dry floodproofed so that the structure is watertight with walls substantially impermeable to the passage of water to the level of the flood protection elevation;
B. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and,
C. Be certified by a registered professional engineer or architect, through the use of a Federal Emergency Management Floodproofing Certificate, that the design and methods of construction are in accordance with Section 1125.03(e)(2)A. and B. of these Subdivision Regulations.
(3) Where flood protection elevation data are not available, the structure shall have the lowest floor, including basement, elevated at least two (2) feet above the highest adjacent natural grade.
(4) Each new nonresidential site shall have direct access to a walkway, driveway, or roadway whose surface elevation is not less than the flood protection elevation and such escape route shall lead directly out of the floodplain area.
(f) Accessory Structures. Relief to the elevation or dry floodproofing standards may be granted for accessory structures containing a floor area of no more than six hundred (600) square feet. Such structures must meet the following standards:
(1) They shall not be used for human habitation;
(2) They shall be constructed of flood resistant materials;
(3) They shall be constructed and placed on the lot to offer the minimum resistance to the flow of flood waters;
(4) They shall be firmly anchored to prevent flotation;
(5) Service facilities such as electrical and heating equipment shall be elevated or floodproofed to or above the level of the flood protection elevation; and
(6) They shall meet the opening requirements of Section 1125.03 (d) (5) C of these Subdivision Regulations.
(g) Recreational Vehicles. Recreational vehicles must meet at least one of the following standards:
(1) They shall not be located on sites in special flood hazard areas for more than 180 days in any twelve-month period, or
(2) They must be fully licensed and ready for highway use, or
(h) Above Ground Gas or Liquid Storage Tanks. All above ground gas or liquid storage tanks shall be anchored to prevent flotation or lateral movement resulting from hydrodynamic and hydrostatic loads.
(i) Assurance of Flood Carrying Capacity. Pursuant to the purpose and methods of reducing flood damage stated in these regulations, the following additional standards are adopted to assure that the reduction of the flood carrying capacity of watercourses is minimized:
(1) Development in Floodways.
A. In floodway areas, development shall cause no increase in flood levels during the occurrence of the base flood discharge. Prior to issuance of a floodplain development permit, the applicant must submit a hydrologic and hydraulic analysis, conducted by a registered professional engineer, demonstrating that the proposed development would not result in any increase in the base flood elevation; or
B. Development in floodway areas causing increases in the base flood elevation may be permitted provided all of the following are completed by the applicant:
1. Meet the requirements to submit technical data in Section 1125.02(j)(1) of these Subdivision Regulations;
2. An evaluation of alternatives which would not result in increased base flood elevations and an explanation why these alternatives are not feasible;
3. Certification that no structures are located in areas which would be impacted by the increased base flood elevation;
4. Documentation of individual legal notices to all impacted property owners within and outside the community, explaining the impact of the proposed action on their property; and
5. Concurrence of the Mayor and the Board of Miami County Commissioners.
(2) Development in Riverine Areas with Base Flood Elevations but No Floodways.
A. In riverine hazard areas identified by FEMA where base flood elevation data are provided but no floodways have been designated, the cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the base flood elevation more than one (1) foot at any point. Prior to issuance of a floodplain development permit, the applicant must submit a hydrologic and hydraulic analysis, conducted by a registered professional engineer, demonstrating that this standard has been met; or,
B. Development in riverine special flood hazard areas identified by FEMA where base flood elevation data are provided but no floodways have been designated causing more than one foot increase in the base flood elevation may be permitted provided all of the following are completed by the applicant:
1. An evaluation of alternatives which would result in an increase of one foot or less of the base flood elevation and an explanation why these alternatives are not feasible;
(3) Alterations of a Watercourse. For the purpose of these regulations, a watercourse is altered when any change occurs within its banks. The extent of the banks shall be established by a field determination of the "bankfull stage." The field determination of "bankfull stage" shall be based on methods presented in Chapter 7 of the USDA Forest Service General Technical Report RM-245, Stream Channel Reference Sites: An Illustrated Guide to Field Technique or other applicable publication available from a Federal, State, or other authoritative source. For all proposed developments that alter a watercourse, the following standards apply:
A. The bankfull flood carrying capacity of the altered or relocated portion of the watercourse shall not be diminished. Prior to the issuance of a floodplain development permit, the applicant must submit a description of the extent to which any watercourse will be altered or relocated as a result of the proposed development, and certification by a registered professional engineer that the bankfull flood carrying capacity of the watercourse will not be diminished.
B. Adjacent communities, the U.S. Army Corps of Engineers, and the Ohio Department of Natural Resources, Division of Water, must be notified prior to any alteration or relocation of a watercourse. Evidence of such notification must be submitted to the Federal Emergency Management Agency.
C. The applicant shall be responsible for providing the necessary maintenance for the altered or relocated portion of said watercourse so that the flood carrying capacity will not be diminished. The Floodplain Administrator may require the permit holder to enter into an agreement with the City specifying the maintenance responsibilities. If an agreement is required, it shall be made a condition of the floodplain development permit.
D. The applicant shall meet the requirements to submit technical data in Section 1125.02(j)(1)A.3 of these Subdivision Regulations when an alteration of a watercourse results in the relocation or elimination of the special flood hazard area, including the placement of culverts.
(4) Compensatory Storage Required for Fill. Fill within a special flood hazard area shall result in no net loss of floodplain storage volume. The volume of the loss of floodwater storage due to filling in the special flood hazard area shall be offset by providing an equal volume of new flood storage by excavation or other compensatory measures at or adjacent to the development site.
(j) Fill. The following standards shall apply to all fill activities in special flood hazard areas:
(1) Fill sites, upon which structures will be constructed or placed, must be compacted to 95 percent of maximum density obtainable with the Standard Proctor Test method or an equivalent method approved by the Floodplain Administrator.
(2) Fill for elevating structures shall extend at least twenty (20) feet laterally from the structure in order to establish a stable building pad.
(3) Fill slopes shall not be steeper than one (1) foot vertical to two (2) feet horizontal.
(4) Adequate protection against erosion and scour shall be provided for all fill slopes. When velocities exceeding five (5) feet per second are expected during an occurrence of the base flood, rock protection or armoring with stone shall be provided. When velocities of five (5) feet per second or less are expected during an occurrence of the base flood, protection may be provided by dense vegetative cover.
(5) Fill shall be composed of clean granular or earthen material. Demolition debris, trash, garbage, and other solid waste materials shall not be used as fill.
(k) Storage of Materials. Outdoor storage of material or equipment not otherwise prohibited in Section 1125.03 (a) (2) shall be firmly anchored to prevent flotation.
(Ord. 73-2021. Passed 1-18-22.)
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