TITLE 12
FLOOD CONTROL
CHAPTER 1
FLOOD DAMAGE PREVENTION
SECTION:
12-1-1: Statutory Authorization, Findings Of Fact, Purpose And Methods
12-1-2: Definitions
12-1-3: General Provisions
12-1-4: Administration
12-1-5: Provisions For Flood Hazard Reduction
12-1-1: STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS:
   A.   Statutory Authorization And Adoption Of Ordinance 1 : The city of Mitchell, South Dakota, elects to comply with the requirements of the national flood insurance act of 1968 (P.L. 90-488, as amended). The national flood insurance program, established in the aforesaid act, provides that areas of the county having a special flood hazard be identified by the federal emergency management agency and that floodplain management measures be applied in such flood hazard areas. The national flood insurance program was broadened and modified with the passage of the flood disaster protection act of 1973 and other legislative measures. It was further modified by the national flood insurance reform act of 1994. The national flood insurance program is administered by the federal emergency management agency, a component of the U.S. department of homeland security.
   B.   Findings Of Fact:
      1.   The flood hazard areas of the city of Mitchell are subject to periodic inundation which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, and extraordinary public expenditures for flood protection and relief, all of which adversely affect the public health, safety and general welfare.
      2.   These flood losses are created by the cumulative effect of obstructions in floodplains which cause an increase in flood heights and velocities, and by the occupancy of flood hazards areas by uses vulnerable to floods and hazardous to other lands because they are inadequately elevated, floodproofed or otherwise protected from flood damage.
   C.   Statement Of Purpose: It is the purpose of this chapter to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed 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 floodplains;
      6.   Help maintain a stable tax base by providing for the sound use and development of flood prone areas in such a manner as to minimize future flood blight areas; and
      7.   Ensure that potential buyers are notified that property is in a flood area.
   D.   Methods Of Reducing Flood Losses: In order to accomplish its purposes, this chapter uses the following methods:
      1.   Restrict or prohibit uses that are dangerous to health, safety or property in times of flood, or cause excessive increases in flood heights or velocities;
      2.   Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
      3.   Control the alteration of natural floodplains, stream channels, and natural protective barriers, which are involved in the accommodation of floodwaters;
      4.   Control filling, grading, dredging and other development which may increase flood damage;
      5.   Prevent or regulate the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards to other lands. (Ord. 2342, 9-20-2010)

 

Notes

1
1. SDCL Ch. 9-36.
12-1-2: DEFINITIONS:
Unless specifically defined below, words or phrases used in this chapter shall be interpreted to give them the meaning they have in common usage and to give this chapter its most reasonable application.
APPEAL BOARD: The planning and zoning commission of the City of Mitchell.
AREA OF FUTURE CONDITIONS FLOOD HAZARD: The land area that would be inundated by the one percent (1%) annual chance (100-year) flood based on future conditions hydrology.
AREA OF SHALLOW FLOODING: A designated AO, AH, AR/AO, AR/AH, or VO zone on a community's flood insurance rate map (FIRM) with a one percent (1%) or greater annual chance of flooding to an average depth of one to three feet (3') where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
AREA OF SPECIAL FLOOD HAZARD: The land in the floodplain within a community subject to a one percent (1%) or greater chance of flooding in any given year. The area may be designated as zone A on the FHBM. After detailed ratemaking has been completed in preparation for publication of the flood insurance rate map, zone A usually is refined into zones A, AO, AH, A1-30, AE, A99, AR, AR/A1-30, AR/AE, AR/AO, AR/AH, AR/A, VO, or V1-30, VE, or V. For purposes of these regulations, the term "special flood hazard area" is synonymous in meaning with the phrase "area of special flood hazard".
AREA OF SPECIAL FLOOD RELATED EROSION HAZARD: The land within a community which is most likely to be subject to severe flood related erosion losses. The area may be designated as zone E on the flood hazard boundary map (FHBM). After the detailed evaluation of the special flood related erosion hazard area; in preparation for publication of the FIRM, zone E may be further refined.
BASE FLOOD: The flood having a one percent (1%) chance of being equaled or exceeded in any given year.
BASE FLOOD ELEVATION (BFE): The water surface elevation of the one percent (1%) annual chance flood. The height in relation to mean sea level expected to be reached by the waters of the base flood at pertinent points in the floodplains of coastal and riverine areas.
BASEMENT: Any area of the building having its floor subgrade (below ground level) on all sides.
BREAKAWAY WALL: A wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces, without causing damage to the elevated portion of the building or supporting foundation system.
BUILDING: See definition of Structure.
CONDITIONAL LETTER OF MAP REVISION (CLOMR): A statement from FEMA that if a project is constructed as planned, a letter of map revision can be issued later.
DEVELOPMENT: Any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials.
EROSION: The process of the gradual wearing away of land masses. This peril is not per se covered under the program.
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".
EXISTING MANUFACTURED HOME PARK OR SUBDIVISION: A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.
EXISTING STRUCTURES: See definition of Existing Construction.
EXPANSION TO AN EXISTING MANUFACTURED HOME PARK OR SUBDIVISION: The preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
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 (1%) or greater chance of occurrence in any given year.
FLOOD INSURANCE RATE MAP (FIRM): An official map of a community, on which the administrator has delineated both the special hazard areas and the risk premium zones applicable to the community.
FLOOD INSURANCE STUDY OR FLOOD ELEVATION STUDY: An examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood related erosion hazards.
FLOOD OR FLOODING:
   A.   A general and temporary condition of partial or complete inundation of normally dry land areas from:
      1. The overflow of inland or tidal waters.
      2. The unusual and rapid accumulation or runoff of surface waters from any source.
      3. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection A1 of this definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.
   B.   The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in subsection A1 of this definition.
FLOODPLAIN OR FLOOD PRONE AREA: Any land area susceptible to being inundated by water from any source (see definition of Flood Or Flooding).
FLOODPROOFING: Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
FLOODWAY: See definition of Regulatory Floodway.
FLOODWAY ENCROACHMENT LINES: The lines marking the limits of floodways on federal, state and local floodplain maps.
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 wave action, bridge openings, and the hydrological effect of urbanization of the watershed.
FUNCTIONALLY DEPENDENT USE: A use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, 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.
HISTORIC STRUCTURE: Any structure that is:
   A.   Listed individually in the national register of historic places (a listing maintained by the department of interior) or preliminarily determined by the secretary of the interior as meeting the requirements for individual listing on the national register;
   B.   Certified or preliminarily determined by the secretary of the interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the secretary to qualify as a registered historic district;
   C.   Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the secretary of the interior; or
   D.   Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
      1.   By an approved state program as determined by the secretary of the interior or
      2.   Directly by the secretary of the interior in states without approved programs.
LETTER OF MAP REVISION (LOMR): An official revision to a FEMA map done by describing the property affected.
LETTER OF MAP REVISION BASED ON FILL (LOMR-F): An official revision to a FEMA map done by describing the property affected with new fill.
LEVEE: A manmade structure usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding.
LEVEE SYSTEM: A flood protection system which consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accordance with sound engineering practices.
LOWEST FLOOR: The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage in an area other than a basement area is not considered a building's lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of CFR section 60.3.
MANUFACTURED HOME: A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term "manufactured home" does not include a "recreational vehicle".
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.
MAP: The flood hazard boundary map (FHBM) or the flood insurance rate map (FIRM) for a community issued by the agency.
MEAN SEA LEVEL: For purposes of the national flood insurance program, the national geodetic vertical datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community's flood insurance rate map are referenced.
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 a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.
NEW MANUFACTURED HOME PARK OR SUBDIVISION: A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of floodplain management regulations adopted by a community.
RECREATIONAL VEHICLE: A vehicle which is:
   A.   Built on a single chassis;
   B.   Four hundred (400) square feet or less when measured at the largest horizontal projection;
   C.   Designed to be self-propelled or permanently towable by a light duty truck; and
   D.   Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
REGULATORY FLOODWAY: The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.
SPECIAL FLOOD HAZARD AREA: See definition of Area Of Special Flood Hazard.
SPECIAL HAZARD AREA: An area having special flood, mudslide (i.e., mudflow), or flood related erosion hazards, and shown on an FHBM or FIRM as zone A, AO, A1-30, AE, AR, AR/A1-30, AR/AE, AR/AO, AR/AH, AR/A, A99, AH, VO, V1-30, VE, V, M, or E.
START OF CONSTRUCTION (For Other Than New Construction Or Substantial Improvements Under The Coastal Barrier Resources Act (Pub. L. 97-348)): Includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvement was 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 slab or footings, the installation of piles, the construction of columns, or 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; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, 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.
STRUCTURE: For floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally aboveground, as well as a manufactured home. Structure, for insurance purposes, means:
   A.   A building with two (2) or more outside rigid walls and a fully secured roof, that is affixed to a permanent site;
   B.   A manufactured home ("a manufactured home", also known as a mobile home, is a structure: built on a permanent chassis, transported to its site in one or more sections, and affixed to a permanent foundation); or
   C.   A travel trailer without wheels built on a chassis and affixed to a permanent foundation, that is regulated under the community's floodplain management and building ordinances or laws.
For the latter purpose, "structure" does not mean a recreational vehicle or a park trailer or other similar vehicle, except as described in subsection C of this definition, or a gas or liquid storage tank.
SUBSTANTIAL DAMAGE: Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred.
SUBSTANTIAL IMPROVEMENT: Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the "start of construction" of the improvement. This term includes structures which have incurred "substantial damage", regardless of the actual repair work performed. The term does not, however, include either:
   A.   Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions or
   B.   Any alteration of a "historic structure", provided that the alteration will not preclude the structure's continued designation as a "historic structure".
VARIANCE: A grant of relief by a community from the terms of a floodplain management regulation.
VIOLATION: The failure of a structure or other development to be fully compliant with the community's floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in CFR sections 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided.
WATER SURFACE ELEVATION: The height, in relation to the national geodetic vertical datum (NGVD) of 1929 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas. (Ord. 2342, 9-20-2010; amd. Ord. O2019-14, 8-19-2019)
12-1-3: GENERAL PROVISIONS:
   A.   Lands To Which This Chapter Applies: This chapter shall apply to all areas of special flood hazard within the city of Mitchell and extraterritorial zoning jurisdiction.
   B.   Basis For Establishing The Areas Of Special Flood Hazard: The areas of special flood hazard identified by the federal emergency management agency in a scientific and engineering report entitled, "The Flood Insurance Study For The City Of Mitchell", dated September 29, 2010, with accompanying flood insurance rate maps (FIRM), dated September 29, 2010, and any revisions thereto are hereby adopted by reference and declared to be a part of this chapter.
   C.   Establishment Of Development Permit: A development permit shall be required to ensure conformance with the provisions of this chapter.
   D.   Compliance: No structure or land shall hereafter be located, altered, or have its use changed without full compliance with the terms of this chapter and other applicable regulations.
   E.   Abrogation And Greater Restrictions: This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
   F.   Interpretation: In the interpretation and application of this chapter, all provisions shall be:
      1. Considered as minimum requirements;
      2. Liberally construed in favor of the governing body; and
      3. Deemed neither to limit nor repeal any other powers granted under state statutes.
   G.   Warning And Disclaimer Or Liability: The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. On rare occasions greater floods can and will occur and flood heights may be increased by manmade or natural causes.
This chapter does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the community or any official or employee thereof for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder. (Ord. 2342, 9-20-2010)
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