Jefferson County, MO Flood Damage Prevention

Flood Losses Resulting From Periodic Inundation. The special flood hazard areas (SFHAs) of Jefferson County, Missouri, are subject to inundation which results 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; all of which adversely affect the public health, safety and general welfare.

General Causes Of The Flood Losses. These flood losses are caused by:

The cumulative effect of development in any delineated floodplain causing increases in flood heights and velocities; and

The occupancy of flood hazard areas by uses vulnerable to floods, hazardous to others, inadequately elevated or otherwise unprotected from flood damages.

Methods Used To Analyze Flood Hazards. The Flood Insurance Study (hereafter "FIS") that is the basis of this Chapter uses a standard engineering method of analyzing flood hazards that consists of a series of interrelated steps:

Selection of a base flood that is based upon engineering calculations which permit a consideration of such flood factors as its expected frequency of occurrence, the area inundated and the depth of inundation. The base flood selected for this Chapter is representative of large floods which are characteristic of what can be expected to occur on the particular streams subject to this Chapter. It is in the general order of a flood which could be expected to have a one-percent chance of occurrence in any one (1) year as delineated on the Federal Insurance Administrator's FIS and illustrative materials for Jefferson County dated June 20, 2019, as amended, and any future revisions thereto.

Calculation of water surface profiles is based on a standard hydraulic engineering analysis of the capacity of the stream channel and overbank areas to convey the regulatory flood.

Computation of a floodway required to convey this flood without increasing flood heights more than one (1) foot at any point.

[Ord. No. 22-0116, 1-28-2022]

Delineation of floodway encroachment lines within which no development is permitted that would cause any increase in flood height.

Delineation of flood fringe, i.e., that area outside the floodway encroachment lines but still subject to inundation by the base flood.

Statement Of Purpose. Unincorporated Jefferson County entered the NFIP on May 16, 1983. It is the purpose of this Chapter to promote the public health, safety and general welfare; to minimize those losses described in Section 405.020(A)(1); to establish or maintain Jefferson County's eligibility for participation in the National Flood Insurance Program (hereafter "NFIP") as defined in 44 Code of Federal Regulations (CFR) 59.22(a)(3); and to meet the requirements of 44 CFR 60.3(d) by applying the provisions of this Chapter to:

Restrict or prohibit uses that are dangerous to health, safety or property in times of flooding or cause undue increases in flood heights or velocities;

Require uses vulnerable to floods, including public facilities that serve such uses, be provided with flood protection at the time of initial construction; and

Protect individuals from buying lands that are unsuited for the intended development purposes due to the flood hazard.

Jefferson County has the authority to enforce the requirements of this Chapter for properties subject to inundation by floodwaters notwithstanding the location of properties within the SFHA.

Section 405.030 Definitions.

[Ord. No. 10-0221 Art. 1, 5-3-2010; Ord. No. 19-0289, 5-30-2019]

ACTUARIAL RATES

See "risk premium rates."

APPURTENANT STRUCTURE

A structure that is on the same parcel of property as the principal structure to be insured and the use of which is incidental to the use of the principal structure.

AREA OF SPECIAL FLOOD HAZARD

The land in the floodplain within a community subject to a one-percent or greater chance of flooding in any given year.

CHIEF EXECUTIVE OFFICER OR CHIEF ELECTED OFFICIAL

The official of the community who is charged with the authority to implement and administer laws, articles, and regulations for that community.

COMMUNITY

Any State or area or political subdivision thereof, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction.

ELEVATED BUILDING

For insurance purposes, a non-basement building which has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.

ELIGIBLE COMMUNITY OR PARTICIPATING COMMUNITY

A community for which the Administrator has authorized the sale of flood insurance under the National Flood Insurance Program (NFIP).

EXISTING CONSTRUCTION

For the purposes of determining rates, structures for which the start of construction commenced before the effective date of the FIRM or before January 1, 1975, for FIRMs effective before that date. Existing construction may also be referred to as "existing structures."

FLOOD ELEVATION DETERMINATION

A determination by the Administrator of the water surface elevations of the base flood, that is the flood level that has a one-percent or greater chance of occurrence in any given year.

FLOOD ELEVATION STUDY

An examination, evaluation and determination of flood hazards.

FREEBOARD

A factor of safety usually expressed in feet above a flood level for purposes of floodplain management. Freeboard tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as bridge openings and the hydrological effect of urbanization of the watershed. Jefferson County's freeboard is three (3) feet for residential structures and non-residential structures above the BFE.

FUNCTIONALLY DEPENDENT USE

A use that cannot perform its intended purpose unless it is located or carried out in close proximity to water. This term includes only docking facilities and facilities that are necessary for the loading and unloading of cargo or passengers, but does not include long-term storage or related manufacturing facilities.

HIGHEST ADJACENT GRADE

The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

MANUFACTURED HOME PARK OR SUBDIVISION

A parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale.

MARKET VALUE OR FAIR MARKET VALUE

An estimate of what is fair, economic, just and equitable value under normal local market conditions.

NEW CONSTRUCTION

For the purposes of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, new construction means structures for which the start of construction commenced on or after the effective date of the floodplain management regulations adopted by a community and includes any subsequent improvements to such structures.

PARTICIPATING COMMUNITY

Also known as an "eligible community," means a community in which the Administrator has authorized the sale of flood insurance.

PRINCIPALLY ABOVE GROUND

At least fifty-one percent (51%) of the actual cash value of the structure, less land value, is above ground.

REMEDY A VIOLATION

To bring the structure or other development into compliance with Federal, State, or local floodplain management regulations; or if this is not possible, to reduce the impacts of its non-compliance.

REPETITIVE LOSS

Flood-related damages sustained by a structure on two (2) separate occasions during a ten-year period for which the cost of repairs at the time of each such flood event equals or exceeds twenty-five percent (25%) of the market value of the structure before the damage occurred.

RISK PREMIUM RATES

Those rates established by the Administrator pursuant to individual community studies and investigations which are undertaken to provide flood insurance in accordance with Section 1307 of the National Flood Disaster Protection Act of 1973 and the accepted actuarial principles. Risk premium rates include provisions for operating costs and allowances.

SPECIAL HAZARD AREA

An area having special flood hazards and shown on an FHBM, FIRM or FBFM as zones (unnumbered or numbered) A and AE.

START OF CONSTRUCTION

Includes substantial improvements, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvements were within one hundred eighty (180) days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slabs or footings, the installation of piles, the construction of columns, any work beyond the stage of excavation, or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling, the installation of streets and/or walkways, excavation for a basement, footings, piers, foundations, the erection of temporary forms, nor installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

STATE COORDINATING AGENCY

That agency of the state government, or other office designated by the governor of the state or by state statute at the request of the Administrator to assist in the implementation of the National Flood Insurance Program (NFIP) in that state.

STRUCTURE

For floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.

For insurance purposes, a walled and roofed building, other than a gas or liquid storage tank, that is principally above ground and affixed to a permanent site, as well as a manufactured home on a permanent foundation.

For the latter purpose, the term includes a building while in the course of construction, alteration or repair, but does not include building materials or supplies intended for use in such construction, alteration or repair, unless such materials or supplies are within an enclosed building on the premises.

SUBDIVISION

The division of a lot, tract or parcel of land into more than two (2) lots, tracts or other divisions of land.

SUBSTANTIAL DAMAGE

Damage of any origin sustained by a structure whereby the cost of restoring the structure to predamaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred. This term includes repetitive loss buildings. For the purposes of this definition, repair is considered to occur when the first repair or reconstruction of any wall, ceiling, floor, or other structural part of the building commences. The term does not apply to:

Any project for improvement of a building required to comply with existing health, sanitary, or safety code specifications which have been identified by the Code Enforcement Official and which are solely necessary to assure safe living conditions; or

Any alteration of an historic structure, provided that the alteration will not preclude the structure's continued designation as an historic structure; or

Any improvement to a building.

SUBSTANTIAL IMPROVEMENT

Any combination of reconstruction, alteration, rehabilitation, addition or other improvement of a structure taking place during a ten-year period in which the cumulative percentage of improvement equals or exceeds fifty percent (50%) of the current market value of the structure. For the purposes of this definition, an improvement occurs when the first alteration of any wall, ceiling, floor, or other structural part of the structure commences, whether or not that alternation affects the external dimensions of the structure. This term includes structures which have incurred repetitive loss or substantial damage, regardless of the actual repair work performed. The term does not, however, include either:

Any project for improvement of a structure to correct existing violations of State or local health, sanitary or safety code specifications that have been identified by the local Code Enforcement Official and which are the minimum necessary to assure safe living conditions; or

Any alteration of an historic structure, provided that the alteration will not preclude the structure's continued designation as an historic structure.

SUBSTANTIALLY IMPROVED EXISTING MANUFACTURED HOME PARKS OR SUBDIVISIONS

Where the repair, reconstruction, rehabilitation or improvement of the streets, utilities and pads equals or exceeds fifty percent (50%) of the value of the streets, utilities and pads before the repair, reconstruction or improvement commenced.

ZONE AH

Areas subject to inundation by one-percent annual chance shallow flooding (usually areas of ponding) where average depths are one (1) to three (3) feet. BFEs derived from detailed hydraulic analyses are shown in this zone. There are no AH Zones mapped in Jefferson County thus far. If a study determines that an area qualifies as an AH Zone in Jefferson County, development will follow the standards set forth in Section 405.060(F).

ZONE AO

Areas subject to inundation by one-percent annual chance shallow flooding (usually sheet flow on sloping terrain) where average depths are one (1) to three (3) feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. There are no AO Zones mapped in Jefferson County thus far. If a study determines that an area qualifies as an AO Zone in Jefferson County, development will follow the standards set forth in Section 405.060(F).

Section 405.040 General Provisions.

[Ord. No. 10-0221 Art. 1, 5-3-2010; Ord. No. 19-0289, 5-30-2019]

Lands To Which Chapter Applies. This Chapter shall apply to all parcels within the jurisdiction of Jefferson County, Missouri, that are unincorporated and portions thereof identified as numbered and unnumbered A Zones, AE, AO and AH Zones on the Flood Insurance Rate Map (hereafter "FIRM") Jefferson County Map Index Panel 29099C1ND0B dated June 20, 2019, as amended, and any future revisions thereto. In all areas covered by this Chapter, no development shall be permitted except through the issuance of a floodplain development permit granted by the Director under such safeguards and restrictions as the Director may reasonably impose for the promotion and maintenance of the general welfare, health of the inhabitants of the County and as specifically noted in Section 405.060.

Compliance. No development located within the special flood hazard areas of the County shall be located, extended, converted or structurally altered without full compliance with the terms of this Chapter and other applicable regulations.

Abrogation And Greater Restrictions. It is not intended by this Chapter to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this Chapter imposes greater restrictions, the provisions of this Chapter shall prevail. All other ordinances inconsistent with this Chapter are hereby repealed to the extent of the inconsistency only.

Interpretation. In their interpretation and application, the provisions of this Chapter shall be held to be minimum requirements, shall be liberally construed in favor of the Governing Body and shall not be deemed a limitation or repeal of any other powers granted by State Statutes.

Warning And Disclaimer Of Liability. The degree of flood protection required by this Chapter is considered reasonable for regulatory purposes and is based on engineering and scientific methods of study. Larger floods may occur on rare occasions, or the flood heights may be increased by man-made or natural causes such as ice jams and bridge openings restricted by debris. This Chapter does not imply that areas outside the floodway and flood fringe or land uses permitted within such areas will be free from flooding or flood damage. This Chapter shall not create a liability on the part of Jefferson County, Missouri, any officer or employee thereof for any flood damages that may result from reliance on this Chapter or any administrative decision lawfully made thereunder.

Severability. If any Section, clause, provision or portion of this Chapter is adjudged unconstitutional or invalid by a court of appropriate jurisdiction, the remainder of this Chapter shall not be affected thereby.

Section 405.050 Administration.

[Ord. No. 10-0221 Art. 1, 5-3-2010; Ord. No. 19-0289, 5-30-2019]

Floodplain Development Permit. A floodplain development permit shall be required for all proposed construction or other development, including the placement of manufactured homes, in the areas described in Section 405.040(A). No person, firm, corporation, organization or any unit of government subject to the jurisdiction of Jefferson County shall initiate any development or substantial improvement or cause the same to be done without first obtaining a separate floodplain development permit for each structure or other development.

Designation Of Floodplain Administrator. The Director is hereby appointed to administer and implement the provisions of this Chapter.

Duties And Responsibilities Of Director. Duties of the Director shall include, but not be limited to:

Review of all applications for floodplain development permits to assure that sites are reasonably safe from flooding and that the floodplain development permit requirements of this Chapter have been satisfied;

Review of all applications for floodplain development permits for proposed development to assure that all necessary permits have been obtained from Federal, State or local governmental agencies from which prior approval is required by Federal, State or local law;

Review all subdivision proposals and other proposed new development, including manufactured home parks or subdivisions, to determine whether such proposals will be reasonably safe from flooding;

Issue floodplain development permits for all approved applications;

Notify affected adjacent communities and the State Emergency Management Agency (hereafter "SEMA") prior to any alteration or relocation of a watercourse and submit evidence of such notification to the Federal Emergency Management Agency (hereafter "FEMA");

Assure that maintenance is provided within the altered or relocated watercourse so that the flood-carrying capacity is not diminished;

Verify and maintain a record of the actual elevation (elevation certificate) in relation to mean sea level, of the lowest floor, including basement, of all new or substantially improved residential structures in the floodplain;

Verify and maintain a record of the actual elevation (elevation certificate) (in relation to mean sea level) that the new or substantially improved non-residential structures have been floodproofed in the floodplain;

When floodproofing techniques are utilized for a particular non-residential structure, the Director shall require certification of the floodproofing techniques from a qualified design professional licensed in the State of Missouri;

10.

Review of all variance requests and assume responsibility to grant or deny a variance request in accordance with Section 405.070.

Application For Floodplain Development Permit. To obtain a floodplain development permit, the applicant shall first file an application in writing on a form furnished for that purpose. Every floodplain development permit application shall:

Describe the land on which the proposed work is to be done by lot, block and tract, house and street address or similar description that will readily identify and specifically locate the proposed structure or work;

Identify and describe the work to be covered by the floodplain development permit;

Indicate the use or occupancy for which the proposed work is intended;

Specify whether development is located in designated special flood hazard area;

A copy of the appropriate FEMA flood map panel (FIRMette) which identifies the site location and map panel number;

Identify the existing base flood elevation and the elevation of the proposed development;

Give such other information as may be required by the Director;

Be accompanied by plans and specifications for proposed construction, including a site plan for the subject property;

Be signed by the permittee (owner/developer) or his or her authorized agent who may be required to submit evidence to indicate such authority;

10.

Be signed by a professional engineer or surveyor licensed in the State of Missouri; and

11.

Be accompanied by any required local, State and Federal permits.

Section 405.060 Provisions For Flood Hazard Reduction.

[Ord. No. 10-0221 Art. 1, 5-3-2010; Ord. No. 19-0289, 5-30-2019]

General Standards.

No permit for floodplain development shall be granted for new construction, substantial improvements and other improvements, including the placement of manufactured homes, within the SFHA unless the conditions of this Section are satisfied.

All areas identified as unnumbered A Zones on the FIRM may be subject to inundation of the one-percent annual chance flood, however, the base flood elevation is not provided. Development within unnumbered A Zones is subject to all provisions of this Chapter. If Flood Insurance Study data is not available, Jefferson County shall require, review and reasonably utilize any base flood elevation or floodway data currently available from Federal, State or other sources.

Until a floodway is designated, no new construction, substantial improvements or other development, including fill, shall be permitted within the SFHA on the FIRM, unless it is determined by an engineering flood study or an engineering certification based on reliable data acceptable to the Director that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one (1) foot at any point within the County.

[Ord. No. 22-0116, 1-28-2022]

All new construction, subdivision proposals, substantial improvements, prefabricated structures, placement of manufactured homes and other developments shall require:

Design or adequate anchorage to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;

Construction with materials resistant to flood damage;

Utilization of methods and practices that minimize flood damages;

All electrical, heating, ventilation, plumbing, air-conditioning equipment and other service facilities be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding;

New or replacement water supply systems and/or sanitary sewage systems be designed to minimize or eliminate infiltration of floodwaters into the systems except for permitted discharges from systems into floodwaters and on-site waste disposal systems be located so as to avoid impairment or contamination; and

Subdivision proposals and other proposed new development, including manufactured home parks or subdivisions, located within special flood hazard areas are required to assure that:

(1)

All such proposals are consistent with the need to minimize flood damage;

(2)

All public utilities and facilities, such as sewer, gas, electrical and water systems, are located and constructed to minimize or eliminate flood damage;

(3)

Adequate drainage is provided so as to reduce exposure to flood hazards;

(4)

All proposals for development, including proposals for manufactured home parks and subdivisions, include within such proposals base flood elevation data, including elevations for the lowest floor of a proposed structure and elevation of land after proposed fill for all lots affected by the SFHA;

(5)

Proposed development that alters the floodplain shall require an engineering study to determine the floodway. Documentation of the changes as determined by the engineering study to the floodplain/floodway boundaries shall be submitted to FEMA as the appropriate LOMC prior to this signing of the record plat or prior to final release of a guarantee agreement for the development; and

(6)

Floodplain development permits shall be required on all development, including structures in an altered floodplain/floodway, until FEMA has approved a LOMR-F removing the development/structure from the floodplain/floodway.

Material Storage And Equipment.

The storage or processing of hazardous materials within the SFHA that in time of flooding become buoyant, flammable, explosive or could be injurious to human, animal or plant life is prohibited unless materials are stored and secured above the base flood elevation.

Storage of other material or equipment may be allowed if not subject to major damage by floods, if firmly anchored to prevent flotation or if readily removable from the area when flooding is imminent.

Agricultural Structures. Structures used solely for agricultural purposes in connection with the production, harvesting, storage, drying or raising of agricultural commodities, including the raising of livestock, may be constructed at grade and wet-floodproofed, provided there is no human habitation or occupancy of the structure; the structure is of single-wall design; there is no permanent retail, wholesale or manufacturing use included in the structure; a variance has been granted from the floodplain management requirements of this Chapter; and a floodplain development permit has been issued.

Accessory Structures. Structures used solely for parking and limited storage purposes, not attached to any other structure on the site, of limited investment value and not larger than four hundred (400) square feet may be constructed at grade and wet-floodproofed, provided there is no human habitation or occupancy of the structure; the structure is of single-wall design; a variance has been granted from the standard floodplain management requirements of this Chapter; and a floodplain development permit has been issued.

Critical Facilities.

All new or substantially improved critical non-residential facilities, including, but not limited to, government buildings, police stations, fire stations, hospitals, ambulance facilities, electric and gas utility stations, orphanages, penal institutions, communication centers, water and sewer pumping stations, water and sewer treatment facilities, transportation maintenance facilities, places of public assembly, emergency aviation facilities and schools shall be elevated above the two-tenths-percent annual chance flood (500-year) level or, together with attendant utility and sanitary facilities, be floodproofed so that below the 500-year flood level that structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. A registered professional engineer or architect shall certify that the standards of this Subsection are satisfied. Such certification shall be provided to the Director as set forth in Section 405.050(C)(9).

No critical facilities shall be constructed in any designated floodway.

All critical facilities shall have access routes that are above the elevation of the 500-year flood.

Hazardous Materials.

All hazardous material storage and handling sites shall be located out of the special flood hazard area and above the 500-year flood elevation. Examples of hazardous materials include, but are not limited to, acetone, ammonia, benzene, calcium carbide, carbon disulfide, celluloid, chlorine, hydrochloric acid, prussic acid, magnesium, nitric acid, oxides of nitrogen, phosphorus, potassium, sodium and sulfur.

Storage and handling sites for quantities of the following materials are prohibited in any space below the base flood elevation: one (1) or more acetylene gas containers, fifty (50) gallons or more of the following: storage tanks, gasoline, charcoal/coal dust, petroleum products; or more than one (1) case of matches/sulfur products or soaps/detergents.

The following items in any quantity are prohibited in any space below the base flood elevation: drugs, food products, tires, lumber/buoyany items.

10.

Non-Conforming Use. A structure or the use of a structure or premises that was lawful before the passage or amendment of the ordinance or pre-FIRM, but which is not in conformity with the provisions of this Chapter, may be continued subject to the following conditions:

If such structure use or utility service is discontinued for six (6) consecutive months, any future use of the building shall conform to this Chapter.

If any non-conforming use or structure is destroyed by any cause, including flood, it shall not be reconstructed if the cost is more than fifty percent (50%) of the pre-damaged value of the structure. This includes structures covered by flood insurance. The costs to repair must be calculated for full repair to before-damage condition, even if the owner elects to do less. This limitation does not include the cost of any alteration to comply with existing State or local health, sanitary, building, safety codes, regulations or the cost of any alteration of a structure listed on the National Register of Historic Places, the State Inventory of Historic Places or local inventory of historic places upon determination.

When it is proposed for a non-conforming structure to be remodeled, renovated, rehabilitated, added to or in any way improved, the total cost of the proposed modifications must be evaluated for substantial improvement. If the total costs of improvement are fifty percent (50%) or more of the building value, the building must come into compliance with this Chapter. Total costs include all structural elements, all interior finishing elements, all utility and service equipment, demolition of storm-damaged building components, labor and costs associated with moving or altering undamaged building components, built-in appliances, hardware, in addition to profit and overhead.

Building value is the market value of the structure only. Land and exterior improvements, such as swimming pools, pool enclosures, accessory structures, landscaping, paving, fencing, etc., must be excluded.

The construction costs to be calculated for both substantial damage and substantial improvement include both the structural and finish or labor and materials. This includes lighting fixtures, built-in appliances, interior moldings, paneling, tiling, wall-to-wall carpet over subflooring, built-in cabinets, etc. The cost to demolish undamaged building components must be established and included. Overhead and profit are also to be included, but not the cost of permits.

If the FIRMs are revised and the flood elevations increase, the fifty-percent rule will apply to structures built before the adoption of the revised FIRMs. All additions to such structures must be elevated above the new BFE, whether or not they are substantial improvements.

In any five-year period, the total costs of all separate permits for the same structure are considered a single improvement and repair project. This period runs from the date of issuance of the certificate of occupancy/certificate of completion, not from the date the building permit was issued. Should the total costs amount to fifty percent (50%) or more of the building value, the building shall be brought into compliance as if it were new construction.

The total cost of the proposed modifications must be obtained by at least two (2) general contractors and submitted to the Code Enforcement Division for review. Where required, due to the nature and complexity of the work and County ordinance, licensed subcontractor bids shall be used in cost evaluation estimates. The bids must be highly detailed, professionally prepared and legible to include all work proposed. Donated or owner-provided labor shall be assigned a fair market value cost and included in the calculation of the construction costs.

11.

Fill. The following standards apply to all fill activities located within an SFHA:

Fill sites upon which structures will be constructed or placed must be compacted to ninety-five percent (95%) of the maximum density obtainable with the Standard Proctor Test method or an acceptable equivalent method.

Fill slopes shall not be steeper than one-foot vertical to three (3) feet horizontal.

Adequate protection against erosion and scour is provided for fill slopes. When expected velocities during the occurrence of the base flood are greater than five (5) feet per second, armoring with stone or rock shall be provided. When expected velocities during the base flood are five (5) feet per second or less, protection shall be provided by vegetative cover.

Fill shall be composed of clean granular or earthen material.

Specific Standards. In all areas identified as SFHA, where base flood elevation data have been provided, as set forth in Section 405.060(A)(2), the following provisions are required:

Residential Construction. New construction or substantial improvement of any residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated to three (3) feet above base flood elevation.

Non-residential construction. New construction or substantial improvement of any commercial, industrial or other non-residential structures shall have the lowest floor, including the basement, elevated to three (3) feet above the base flood elevation or, together with attendant utility and sanitary facilities, be floodproofed so that below the base flood elevation the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall certify that the standards of this Subsection are satisfied. Such certification shall be provided to the Director as set forth in Section 405.050(C)(9).

Require, for all new construction and substantial improvements, that fully enclosed areas below the lowest floor be used solely for parking of vehicles, building access or storage in an area other than a basement and that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria:

A minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided; and

The bottom of all openings shall be no higher than one (1) foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

Manufactured Homes. All manufactured homes to be placed within the SFHA on Jefferson County's FIRM shall be required to be installed using methods and practices that minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist 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. One (1) of the following two (2) instances applies for the placement of manufactured homes.

All manufactured homes that are placed or substantially improved within the SFHA on Jefferson County's FIRM at any of the following sites:

Outside of manufactured home park or subdivision; or

In a new manufactured home park or subdivision; or

In an expansion to an existing manufactured home park or subdivision; or

In an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as the result of a flood are required to be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to three (3) feet above the base flood elevation and be securely attached to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

All manufactured homes to be placed or substantially improved on sites where manufactured homes have not been substantially damaged from flooding in an existing manufactured home park or subdivision within the SFHA on Jefferson County's FIRM, that are not subject to the provisions of Subsection (c)(1)(b) above, be elevated so that either:

The lowest floor of the manufactured home is at three (3) feet above the base flood level; or

The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade and be securely attached to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

Floodway. Located within areas of special flood hazard established in Section 405.040(A) are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris and potential projectiles, the following provisions shall apply:

Jefferson County shall adopt a regulatory floodway based on the principle that the area chosen for the regulatory floodway must be designed to carry the waters of the base flood without increasing the water surface elevation of that flood more than one (1) inch at any point.

Jefferson County shall prohibit any encroachments, including fill, new construction, substantial improvements and other development, within the adopted regulatory floodway.

An exception may apply if it can be determined through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the County during the occurrence of the base flood discharge.

In addition, for projects that require the realignment, relocation or modification to the stream bed or stream channel of the floodway, other than those related to public infrastructure improvements, a geomorphological study is required to be conducted by a professional who is qualified in accordance with standards adopted by the Director to address the issue involved. The geomorphological study shall include, where appropriate:

Conceptual designs for relocating the stream to its new location.

Evaluation of the geologic and geomorphologic factors that might cause the relocated stream to meander unexpectedly or move back to its current location.

Evaluation of existing soils and potential for erosion or sedimentation with the new stream cross section.

Armoring techniques (other than concrete or riprap) necessary to limit future stream migration to the confines of the relocated corridor.

Determination of appropriate sinuosity for the relocated stream as well as appropriate pool and riffle section geometry.

Evaluation of impacts of the project on the upstream and downstream existing stream sections for whatever distance impacts may be experienced.

Determining the appropriate stream channel cross section for both low-flow and flood-flow conditions.

Maximum amount of anticipated stream movement in fifty (50) years.

Recommendations for appropriate vegetative plantings to be required.

Any other impacts of the project and recommendations for requirements that will mitigate the effect on the environment of the affected floodplain.

Estimated maintenance requirements for the project for a fifty-year period.

If Section 405.060(D)(2) is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Section 405.060.

In unnumbered A Zones, Jefferson County shall obtain, review and reasonably utilize any base flood elevation or floodway data currently available from Federal, State or other sources as set forth in Section 405.060(A)(2).

Recreational Vehicles.

All recreational vehicles placed on sites within the SFHA on Jefferson County's FIRM either:

Must be on the site for fewer than one hundred eighty (180) consecutive days and be fully licensed and ready for highway use; or

Must meet the permitting, elevating and the anchoring requirements for manufactured homes of this Chapter.

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.

Located within the areas of special flood hazard as described in Section 405.020(A)(1) are areas designated as AO zones. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate. The following provisions apply:

AO Zones.

All new construction and substantial improvements of residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least three (3) feet if no depth number is specified).

All new construction and substantial improvements of any commercial, industrial, or other non-residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community FIRM [at least three (3) feet if no depth number is specified] or together with attendant utilities and sanitary facilities be completely floodproofed so that the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

Adequate drainage paths shall be required around structures on slopes, in order to guide floodwaters around and away from proposed structures.

AH Zones.

The specific standards for all areas of special flood hazard where base flood elevation has been provided shall be required as set forth in Section 405.060(B).

Adequate drainage paths shall be required around structures on slopes, in order to guide floodwaters around and away from proposed structures.

Section 405.070 Floodplain Management Variance Procedures.

[Ord. No. 10-0221 Art. 1, 5-3-2010; Ord. No. 19-0289, 5-30-2019]

Establishment Of Appeal Board. The Board of Building Appeals, as established by Jefferson County, shall hear and decide appeals for variances from the floodplain management requirements of this Chapter.

Responsibility Of The Board Of Building Appeals For Variances. Where an application for a floodplain development permit or variance is denied by the Director, the applicant may apply directly to the Board of Building Appeals. The Board of Building Appeals shall hear and decide appeals when it is alleged that there is an error in any requirement, decision or determination in the enforcement or administration of this Chapter.

Further Appeals. Any person aggrieved by the decision of the Board of Building Appeals may appeal such decision in the Circuit Court thirty (30) days after the written decision is issued.

Floodplain Management Variance Criteria. In passing upon such applications for variances, the Board of Building Appeals shall consider all technical data and evaluations, all relevant factors, standards specified in other Sections of this Chapter and the following criteria:

The danger to life and property due to flood damage;

The danger that materials may be swept onto other lands to the injury of others;

The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

The importance of the services provided by the proposed facility to Jefferson County;

The necessity to the facility of a waterfront location, where applicable;

The availability of alternative locations, not subject to flood damage, for the proposed use;

The compatibility of the proposed use with existing and anticipated development;

The relationship of the proposed use to the Master Plan and Floodplain Management Program for that area;

The safety of access to the property in times of flood for ordinary and emergency vehicles;

10.

The expected heights, velocity, duration, rate of rise and sediment transport of the floodwaters, if applicable, expected at the site; and

11.

The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical and water systems, streets and bridges.

Conditions For Approving Floodplain Management Variances.

Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (1/2) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items in Subsection (E)(2) through (6) below have been fully considered. As the lot size increases beyond the one-half (1/2) acre, the technical justification required for issuing the variance increases.

Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places, the State Inventory of Historic Places or local inventory of historic places upon determination, provided the proposed activity will not preclude the structure's continued historic designation.

Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.

Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

Variances shall only be issued upon:

A showing of good and sufficient cause;

A determination that failure to grant the variance would result in exceptional hardship to the applicant; and

A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public or conflict with existing local laws or ordinances.

Jefferson County shall notify the applicant in writing over the signature of the Director that:

The issuance of a variance to construct a structure below base flood level will result in increased premium rates for flood insurance up to amounts as high as twenty-five dollars ($25.00) for one hundred dollars ($100.00) of insurance coverage; and

Such construction below the base flood level increases risks to life and property. Such notification shall be maintained with the record of all variance actions as required by this Chapter.

Conditions For Approving Variances For Agricultural Structures.

A variance is needed for agricultural structure if the structure is wet-floodproofed and is built at grade below the BFE.

Any variance granted for an agricultural structure shall be decided individually based on a case-by-case analysis of the building's unique circumstances. Variances granted shall meet the following conditions as well as those criteria and conditions set forth in Section 405.070(D) and (E) of this Chapter.

In order to minimize flood damages during the 100-year flood and the threat to public health and safety, the following conditions shall be included for any variance issued for agricultural structures that are constructed at grade and wet-floodproofed.

All agricultural structures considered for a variance from the floodplain management regulations of this Chapter shall demonstrate that the varied structure is located in wide, expansive floodplain areas and no other alternate location outside of the special flood hazard area exists for the agricultural structure. Residential structures, such as farmhouses, cannot be considered agricultural structures.

Use of the varied structures must be limited to agricultural purposes in the SFHA only as identified on Jefferson County's Flood Insurance Rate Map (FIRM).

For any new or substantially damaged agricultural structures, the exterior and interior building components and elements (i.e., foundation, wall framing, exterior and interior finishes, flooring, etc.) below the base flood elevation must be built with flood-resistant materials in accordance with Section 405.060(A)(4)(b) of this Chapter.

The agricultural structures must be adequately anchored to prevent flotation, collapse or lateral movement of the structures in accordance with Section 405.060(A)(4)(a) of this Chapter. All of the building's structural components must be capable of resisting specific flood-related forces, including hydrostatic, buoyancy and hydrodynamic and debris impact forces.

Any mechanical, electrical or other utility equipment must be located above the base flood elevation or floodproofed so that they are contained within a watertight, floodproofed enclosure that is capable of resisting damage during flood conditions in accordance with Section 405.060(A)(4)(d) of this Chapter.

The agricultural structures must meet all National Flood Insurance Program (NFIP) opening requirements. The NFIP requires that enclosure or foundation walls, subject to the one-percent annual chance of flood, contain openings that will permit the automatic entry and exit of floodwaters in accordance with Section 405.060(B)(3) of this Chapter.

The agricultural structures must comply with the floodplain management floodway encroachment provisions of Section 405.060(D)(2) of this Chapter. No variances may be issued for agricultural structures within any designated floodway, if any increase in flood levels would result during the one-percent annual chance of flood.

Major equipment, machinery or other contents must be protected from any flood damage.

No disaster relief assistance under any program administered by any Federal agency shall be paid for any repair or restoration costs of the agricultural structures.

Notification.

(1)

Jefferson County shall notify the applicant in writing over the signature of the Director that:

(a)

(b)

Such construction below the base flood level increases risks to life and property.

(2)

Such notification shall be maintained with the record of all variance actions as required by this Chapter.

Wet-floodproofing construction techniques must be reviewed and approved by Jefferson County and a registered professional engineer or architect prior to the issuance of any floodplain development permit for construction.

Conditions For Approving Variances For Accessory Structures.

A variance is needed for accessory structures if the structure is wet-floodproofed and if the lowest floor is built at grade below the BFE.

Any variance granted for an accessory structure shall be decided individually based on a case-by-case analysis of the building's unique circumstances. Variances granted shall meet the following conditions as well as those criteria and conditions set forth in Section 405.070(D) and (E) of this Chapter.

In order to minimize flood damages during the one-percent annual chance of flood and the threat to public health and safety, the following conditions shall be included for any variance issued for accessory structures that are constructed at grade and wet-floodproofed.

Use of the accessory structures must be solely for parking and limited storage purposes in the SFHA only as identified on Jefferson County's Flood Insurance Rate Map (FIRM).

For any new or substantially damaged accessory structures, the exterior and interior building components and elements (i.e., foundation, wall framing, exterior and interior finishes, flooring, etc.) below the base flood elevation must be built with flood-resistant materials in accordance with Section 405.060(A)(4)(b) of this Chapter.

The accessory structures must be adequately anchored to prevent flotation, collapse or lateral movement of the structure in accordance with Section 405.060(A)(4)(a) of this Chapter. All of the building's structural components must be capable of resisting specific flood-related forces, including hydrostatic, buoyancy and hydrodynamic and debris impact forces.

The accessory structures must meet all National Flood Insurance Program (NFIP) opening requirements. The NFIP requires that enclosure or foundation walls, subject to the one-percent annual chance of flood, contain openings that will permit the automatic entry and exit of floodwaters in accordance with Section 405.060(B)(3) of this Chapter.

The accessory structures must comply with the floodplain management floodway encroachment provisions of Section 405.060(D)(2) of this Chapter. No variances may be issued for accessory structures within any designated floodway, if any increase in flood levels would result during the one-percent annual chance of flood.

Equipment, machinery or other contents must be protected from any flood damage.

No disaster relief assistance under any program administered by any Federal agency shall be paid for any repair or restoration costs of the accessory structures.

Notification.

(1)

Jefferson County shall notify the applicant in writing over the signature of the Director that:

(a)

The issuance of a variance to construct a structure below base flood level will result in increased premium rates for flood insurance; and

(b)

Such construction below the base flood level increases risks to life and property.

(2)

Such notification shall be maintained with the record of all variance actions as required by this Chapter.

Conditions For Approving Variances For Temporary Development. A variance may be issued for temporary uses that are not otherwise in compliance with this Chapter. Temporary uses may include, but are not limited to, development, parking or storage of recreational vehicles, temporary construction offices, temporary business facilities or other structures. Temporary development shall be removed upon the expiration of the 180-day permit period and site shall be returned to a predevelopment state. Variances granted shall meet the following conditions as well as those criteria and conditions set forth in Section 405.070(D) and (E) of this Chapter.

A temporary use may be considered for location within the one-percent annual chance of flood event, also referred to as the 100-year floodplain, only when all of the following criteria are met:

The temporary use is unique to the land to be developed and cannot be located outside of the floodplain nor meet the NFIP design standards;

Denial of the variance will create an undue hardship on the property owner.

Once all of the above conditions are met, an application for a variance must be made to the Director. The Director shall consider all applications for variances for a temporary use based on the following criteria:

The placement of any temporary use within the SFHA as shown on the County's adopted FEMA/NFIP map shall require an approved floodplain development permit. The floodplain development permit shall be valid for a period not to exceed one hundred eighty (180) days.

Applications, for a temporary use to be located in the SFHA, shall conform to the decision of the Director and/or the appeal process prior to any action on the variance request.

An emergency plan for the removal of the temporary use that includes specific removal criteria and time frames from the agency or firm responsible for providing the manpower, equipment and the relocation and disconnection of all utilities shall be required as part of the floodplain development permit application for the placement of any temporary use.

On or before the expiration of the end of the 180-day permit period, the temporary use shall be removed from the site. All utilities, including water, sewer, communication and electrical services, shall be disconnected.

To ensure the continuous mobility of the temporary structure for the duration of the permit, the temporary structure shall retain its wheels and tires, licenses and towing appurtenance on the structures at all times.

Under emergency flooding conditions, the temporary use shall be removed immediately and as specified in the emergency removal plan.

Location of any temporary use within the regulatory floodway requires the provision of a no-rise certificate by a registered professional engineer or evidence the use will have no impact off premises.

Violation for non-compliance with any of the stated conditions of the floodplain development permit during the term thereof shall make the permit subject to revocation. Issuance of permit revocation notice shall be made to the landowner and/or the occupant of the land.

Any deviation from the approved site plan shall be deemed a violation of the floodplain development permit approval, and the uses allowed shall automatically be revoked. The subsequent use of the land shall be as it was prior to the temporary use approval. In the event of any violation, all permitted temporary uses shall be deemed a violation of this Chapter and shall be illegal, non-conforming uses and shall be summarily removed and abated.

If a time extension is requested or if the temporary use is to be returned to its previously occupied site, the process for issuing a floodplain development permit must be repeated in full. Any subsequent permit shall be valid for up to one hundred eighty (180) days only.

Section 405.080 Penalties For Violation.

[Ord. No. 10-0221 Art. 7, 5-3-2010]

Violation of the provisions of this Chapter or failure to comply with any of its requirements, including violations of conditions and safeguards established in connection with granting of variances, shall constitute a misdemeanor. Any person who violates this Chapter or fails to comply with any of its requirements shall, upon conviction thereof, be fined not more than one thousand dollars ($1,000.00) or imprisonment for not more than one (1) year, or both, and, in addition, shall pay all costs and expenses involved in the case. Each day such violation continues shall be considered a separate offense. Violations shall be prosecuted in the Jefferson County Municipal Court by the Jefferson County Municipal Prosecutor. Nothing herein contained shall prevent the County from taking such other lawful action as is necessary to prevent or remedy any violation.

Section 405.090 Amendments.

[Ord. No. 10-0221 Art. 8, 5-3-2010]

The regulations, restrictions and boundaries set forth in this Chapter may from time to time be amended, supplemented, changed or appealed to reflect any and all changes in the National Flood Disaster Protection Act of 1973, provided however, that no such action may be taken until after a public hearing in relation thereto, at which parties of interest and citizens shall have an opportunity to be heard. Notice of the time and place of such hearing shall be published in a newspaper of general circulation in Jefferson County. At least twenty (20) days shall elapse between the date of this publication and the public hearing. A copy of such amendments will be provided to the Region VII office of the Federal Emergency Management Agency (FEMA). The regulations of this Chapter are in compliance with the National Flood Insurance Program (NFIP) regulations.