HomeMy WebLinkAbout2022-11-21 Ordinance 3059_Floodplain ManagementORDINANCE NO.3059
AN ORDINANCE TO AMEND CHAPTER 170 OF THE MUNICIPAL CODE OF THE
CITY OF WAUKEE, IOWA, BY REMOVING AND REPLACING CHAPTER 170,
FLOODPLAIN MANAGEMENT
BE IT ORDAINED by the City Council of the City of Waukee:
Section 1. Chapter 170, Waukee Municipal Code, Floodplain Management, is hereby
amended by removing and replacing Chapter 170 with following:
170.01 STATUTORY AUTHORITY, FINDINGS OF FACT, AND PURPOSE.
1. Statutory Authority. The legislature of the State of Iowa has, in Chapter 414, Code of Iowa, as
amended, delegated the power to a city to enact zoning regulations to secure safety from flood and to
promote health and the general welfare.
2. Findings of Fact.
A. The flood hazard areas of the City are subject to periodic inundation, which can 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, all of which adversely
affect the public health, safety, and general welfare of the community.
B. These flood losses, hazards, and related adverse effects are caused by: (i) the occupancy of flood
hazard areas by uses vulnerable to flood damages, which create hazardous conditions as a result of being
inadequately elevated or otherwise protected from flooding; and (ii) the cumulative effect of obstructions
on the floodplain, causing increases in flood heights and velocities.
C. This chapter relies upon engineering methodology for analyzing flood hazards which is consistent
with the standards established by the State Department of Natural Resources.
3. Statement of Purpose: It is the purpose of this chapter to protect and preserve the rights, privileges,
and property of the City and its residents and to preserve and improve the peace, safety, health, welfare,
and comfort, and convenience of its residents by minimizing those flood losses described in Subsection
2A of this section, with provisions designed to:
A. Reserve sufficient floodplain area for the conveyance of flood flows so that flood heights and
velocities will not be increased substantially.
B. Restrict or prohibit uses which are dangerous to health, safety, or property in times of flood or
which cause excessive increases in flood heights or velocities.
C. Require that uses vulnerable to floods, including public facilities which serve such uses, be
protected against flood damage at the time of initial construction or substantial improvement.
D. Protect individuals from buying lands which may not be suited for intended purposes because of
flood hazard.
E. Assure that eligibility is maintained for property owners in the community to purchase flood
insurance through the National Flood Insurance Program.
170.02 DEFINITIONS.
Unless specifically defined in this section, words or phrases used in this chapter shall be interpreted so as
to give thern the meanings they have in common usage and to give this chapter its most reasonable
application.
1. "Appurtenant structure" means a structure which is on the same parcel of the property as the principal
structure to be insured and the use of which is incidental to the use of the principal structure.
2. "Base flood" means the flood having one percent chance of being equaled or exceeded in any given
year. (Also see "100-year flood.")
3. "Base flood elevation (BEE) means the elevation floodwaters would reach at a particular site during
the occurrence of a base flood event.
4. "Basement" means any enclosed area of a building which has its floor or lowest level below ground
level (subgrade) on all sides. (Also see -lowest floor.")
5. "Development" means any manmade change to improved or unimproved real estate, including but not
limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, drilling
operations or storage of equipment or materials. "Development" does not include "minor projects" or
"routine maintenance of existing buildings and facilities" as defined in this section. It also does not
include gardening, plowing, and similar practices that do not involve filling or grading.
6. "Enclosed area below lowest floor" means the floor of the lowest enclosed area in a building when all
the following criteria are met:
A. The enclosed area is designed to flood to equalize hydrostatic pressure during flood events with
walls or openings that satisfy the provisions of Section 170.15(2)(D)( I ) of this chapter, and
B. The enclosed area is unfinished (not carpeted, drywalled, etc.) and used solely for low damage
potential uses such as building access, parking, or storage, and
C. Machinery and service facilities (e.g., hot water heater, furnace, electrical service) contained in the
enclosed area are located at least one foot above the base flood elevation, and
D. The enclosed area is not a "basement" as defined in this section.
7. "Existing construction" means any structure for which the "start of construction" commenced before
the effective date of the community's floodplain management regulations adopted by the community.
8. "Existing factory -built home park or subdivision" means a factory -built home park or subdivision for
which the construction of facilities for servicing the lots on which the factory -built 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 first floodplain
management regulations adopted by the community.
9. "Expansion of existing factory -built home park or subdivision" means the preparation of additional
sites by the construction of facilities for servicing the lots on which the factory -built 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).
10. "Factory -built home" means any structure, designed for residential use which is wholly or in
substantial part, made, fabricated, formed, or assembled in manufacturing facilities for installation or
assembly and installation, on a building site. For the purpose of this chapter, factory -built homes include
mobile homes, manufactured homes, and modular homes and also include "recreational vehicles" that are
placed on a site for greater than 180 consecutive days and not fully licensed for and ready for highway
use.
11. "Factory -built home park or subdivision" means a parcel or contiguous parcels of land divided into
two or more factory -built home lots for sale or lease.
12. "Five hundred year flood" means a flood, the magnitude of which has a two -tenths percent chance of
being equaled or exceeded in any given year or which, on average, will be equaled or exceeded at least
once every 500 years.
13. "Flood" means a general and temporary condition of partial or complete inundation of normally dry
land areas resulting from the overflow of streams or rivers or from the unusual and rapid runoff of surface
waters fro►n any source.
14. "Flood Insurance Rate Map (FIRM)" ►neans the official ►nap prepared as part of (but published
separately from) the Flood Insurance Study, which delineates both the flood hazard areas and the risk
premium zones applicable to the community.
15. "Flood insurance study (FIS)" means a report published by FEMA for a community issued along
with the community's Flood Insurance Rate Map(s). The study contains such background data as the base
flood discharge and water surface elevations that were used to prepare the FIRM.
16. "Floodplain" means any land area susceptible to being inundated by water as a result of a flood.
17. "Floodplain management" means an overall program of corrective and preventive measures for
reducing flood damages and promoting the wise use of floodplains, including but not limited to
emergency preparedness plans, flood control works, floodproofing and floodplain management
regulations.
18. "Floodproofing" means any combination of structural and nonstructural additions, changes, or
adjustments to structures, including utility and sanitary facilities, which will reduce or eliminate flood
damage to such structures.
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19. "Floodway" means the channel of a river or stream and those portions of the floodplains adjoining
the channel, which are reasonably required to carry and discharge floodwaters or flood flows so that
confinement of flood flows to the floodway area will not cumulatively increase the water surface
elevation of the base flood by more than one foot.
20. "Floodway fringe" means those portions of the Special Flood Hazard Area outside the floodway.
21. "Highest Adjacent Grade" means the highest natural elevation of the ground surface prior to
construction next to the proposed walls of a structure.
22. "Historic structure" means any structure that is:
A. Listed individually in the National Register of Historic Places, maintained by the Department of
Interior, or preliminarily determined by the Secretary of the Interior as meeting the requirements for
individual listing of 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 by either (i) an approved state program as determined by the Secretary
of the Interior or (ii) directly by the Secretary of the Interior in states without approved programs.
23. "Lowest floor" means the floor of the lowest enclosed area in a building including a basement except
when the criteria listed in the definition of enclosed area below lowest floor are met.
24. "Maximum damage potential development" means hospitals and like institutions; buildings or
building complexes containing documents, data, or instruments of great public value; buildings or
building complexes containing materials dangerous to the public or fuel storage facilities; power
installations needed in emergency or other buildings or building complexes similar in nature or use.
25. "Minor projects" means small development activities (except for filling, grading, and excavating)
valued at less than $500.00.
26. "New construction" (new buildings, factory -built home parks) means those structures or
development for which the start of construction commenced on or after the effective date of the first
floodplain management regulations adopted by the community.
27. "New factory -built home park or subdivision" means a factory -built home park or subdivision for
which the construction of facilities for servicing the lots on which the factory -built 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 the first
floodplain management regulations adopted by the community.
28. "Recreational vehicle" means 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 a temporary living quarters for
recreational, camping, travel, or seasonal use.
29. "Routine maintenance of existing buildings and facilities" means repairs necessary to keep a
structure in a safe and habitable condition that do not trigger a building permit, provided they are not
associated with a general improvement of the structure or repair of a damaged structure. Such repairs
include:
A. Normal maintenance of structures such as re -roofing, replacing roofing tiles, and replacing siding;
B. Exterior and interior painting, papering, tiling, carpeting, cabinets, counter tops, and similar finish
work;
C. Basement sealing;
D. Repairing or replacing damaged or broken window panes,
E. Repairing plumbing systems, electrical systems, heating or air conditioning systems, and repairing
wells or septic systems.
30. "Special flood hazard area (SFHA)" means the land within a community subject to the "base flood."
This land is identified on the community's Flood Insurance Rate Map as Zone A, Al-30, AE, AH, AO,
AR, and/or A99.
31. "Start of construction" includes substantial improvement, and means the date the development
permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition,
placement, or other improvement, was within 180 days of the permit date. The actual start means either
the first placement or permanent construction of a structure on a site, such as pouring of a slab or
footings, the installation of pile, the construction of columns, or any work beyond the stage of excavation;
or the placement of a factory -built 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 the building, whether or not that alteration affects the external dimensions of the
building.
32. "Structure" means anything constructed or erected on the ground or attached to the ground,
including, but not limited to, buildings, factories, sheds, cabins, factory -built homes, storage tanks, grain
storage facilities, and other similar uses.
33. "Substantial damage" means damage of any origin sustained by a structure whereby the cost of
restoring the structure to its before damage condition would equal or exceed 50 percent of the market
value of the structure before the damage occurred. Volunteer labor and donated materials shall be
included in the estimated cost of repair. Substantial damage also means flood -related damages sustained
by a structure on two separate occasions during a 10-year period for which the cost of repairs at the time
of such flood event, on the average, equals or exceeds 25 percent of the market value of the structure
before the damage occurred. Volunteer labor and donated materials shall be included in the estimated cost
of repair.
34. "Substantial improvement" means any improvement to a structure which satisfies either of the
following criteria:
A. Any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50
percent of the market value of the structure either (1) before the "start of construction" of the
improvement, or (ii) if the structure has been "substantially damaged" and is being restored, before the
damage occurred.
The term does not, however, include 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.
The term also does not include any alteration of a "historic structure," provided the alteration will not
preclude the structure's designation as a "historic structure."
B. Any addition which increases the original floor area of a building by 25 percent or more. All
additions constructed after the effective date of the first floodplain management regulations adopted by
the community shall be added to any proposed addition in determining whether the total increase in
original floor space would exceed 25 percent.
35. "Variance" means a grant of relief by a community from the terms of the floodplain management
regulations.
36. "Violation" means the failure of a structure or other development to be fully compliant with the
community's floodplain management regulations.
170.03 GENERAL PROVISIONS.
1. Lands to Which Chapter Applies. The provisions of this chapter shall apply to all lands within the
jurisdiction of the City shown on the official floodplain zoning map as being within the boundaries of the
floodway, floodway fringe, general floodplain, and shallow flooding (overlay) districts, as established in
this chapter.
2. Establishment of Official Floodplain Zoning Map. The Flood Insurance Rate Map (FIRM) for Dallas
County and Incorporated Areas, City of Waukee, Panels 19049CO214G, 0220F, 0240F, 0327G, 0335F,
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0341G, 0342G, 0343G, and 0355F, dated December 15, 2022, which were prepared as part of the Flood
Insurance Study for Dallas County, is (are) hereby adopted by reference and declared to be the Official
Floodplain Zoning Map. The flood profiles and all explanatory material contained within the Flood
Insurance Study are also declared to be a part of this section.
3. Rules for Interpretation of District Boundaries. The boundaries of the zoning district areas shall be
determined by scaling distances on the Official Floodplain Zoning Map. When an interpretation is needed
as to the exact location of a boundary, the Administrative Official shall make the necessary interpretation.
The Board of Adjustment shall hear and decide appeals when it is alleged that there is an error in any
requirement, decision, or determination made by the Administrative Official in the enforcement or
administration of this chapter.
4. Compliance. No structure or land shall hereafter be used and no structure shall be located, extended,
converted, or structurally altered without full compliance with the terms of this chapter and other
applicable regulations which apply to uses within the jurisdiction of this chapter.
5. 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 provision of this chapter shall prevail. All other ordinances inconsistent with this chapter
are hereby repealed to the extent of the inconsistency only.
6. Interpretation. In their interpretation and application, the provisions of this chapter shall be held to be
minimum requirements and 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.
7. Warning and Disclaimer of Liability. The standards required by this chapter are considered reasonable
for regulatory purposes. This chapter does not imply that areas outside the designated Floodplain
(Overlay) District areas will be free from flooding or flood damages. This chapter shall not create liability
on the part of the City or any officer or employee thereof for any flood damages that result from reliance
on this chapter or any administrative decision lawfully made there under.
8. Severability. If any section, clause, provision, or portion of this chapter is adjudged unconstitutional
or invalid by a court of competent jurisdiction, the remainder of the chapter shall not be affected thereby.
170.04 ADMINISTRATION.
1. Appointment, Duties, and Responsibilities of Administrative Official.
A. The Administrative Official is hereby appointed to implement and administer the provisions of this
chapter and will herein be referred to as the Administrator.
B. Duties and responsibilities of the Administrator shall include, but not necessarily be limited to the
following:
(1) Review all floodplain development permit applications to assure that the provisions of this
chapter will be satisfied.
(2) Review floodplain development applications to assure that all necessary permits have been
obtained from federal, state, and local governmental agencies including approval when required from the
Department of Natural Resources for floodplain construction.
(3) Record and maintain a record of (1) the elevation (in relation to North American Vertical Datum
1988 of the lowest flood (including basement) of all new or substantially improved structures or (ii) the
elevation to which new or substantially improved structures have been floodproofed.
(4) Notify adjacent communities/counties and the Department of Natural Resources prior to any
proposed alteration or relocation of a watercourse and submit evidence of such notifications to the Federal
Emergency Management Agency.
(5) Keep a record of all permits, appeals, and such other transactions and correspondence pertaining
to the administration of this chapter.
(6) Submit to the Federal Insurance Administrator an annual report concerning the community's
participation, utilizing the annual report form supplied by the Federal Insurance Administrator.
(7) Notify the Federal Insurance Administrator of any annexations or modifications to the
community's boundaries.
(8) Review subdivision proposals to ensure such proposals are consistent with the purpose of this
chapter and advise the Planning and Zoning Commission and City Council of potential conflict.
(9) Maintain the accuracy of the community's Flood Insurance Rate Maps when:
(i) Development placed within the Floodway (Overlay) District results in any of the following:
(a) An increase in the Base Flood Elevations, or
(b) Alteration to the floodway boundary
(ii) Development placed in Zones A, AE, AH, and A 1-30 that does not include a designated
floodway that will cause a rise of more than one foot in the base elevation; or
(iii) Development relocates or alters the channel.
Within six months of the completion of the development, the applicant shall submit to FEMA all
scientific and technical data necessary for a Letter of Map Revision.
(10) Perform site inspections to ensure compliance with the standards of this chapter.
(11) Forward all requests for variances to the Board of Adjustment for consideration. Ensure all
requests include the information ordinarily submitted with applications as well as any additional
information deemed necessary to the Board of Adjustment.
2. Floodplain Development Permit.
A. Permit Required. A Floodplain Development Permit issued by the Administrator shall be secured
prior to any floodplain development (any man-made change to improved and unimproved real estate,
including but not limited to buildings or other structures, mining, filling, grading, paving, storage of
materials or equipment, excavation or drilling operations), including the placement of factory -built
homes.
B. Application for Permit. Application shall be made on forms furnished by the Administrator and
shall include the following:
(1) Description of the work to be covered by the permit for which application is to be made.
(2) Description of the land on which the proposed work is to be done (i.e., lot, block, track, street
address, or similar description) that will readily identify and locate the work to be done.
(3) Location and dimensions of all structures and additions.
(4) Indication of the use or occupancy for which the proposed work is intended.
(5) Elevation of the base flood.
(6) Elevation (in relation to North American Vertical Datum 1988) of the lowest floor (including
basement) of structures or of the level to which a structure is to be floodproofed.
(7) For structures being improved or rebuilt, the estimated cost of improvements and market value of
the structure prior to the improvements.
(8) Such other information as the Administrator deems reasonably necessary (e.g., drawings or a site
plan) for the purpose of this chapter.
C. Action on Permit Application. The Administrator shall, within a reasonable time, make a
determination as to whether the proposed floodplain development meets the applicable standards of this
chapter and shall approve or disapprove he application. For disapprovals, the applicant shall be informed,
in writing, of the specific reasons therefore. The Administrator shall not issue permits for variances
except as directed by the Board of Adjustment.
D. Construction and Use to be as Provided in Application and Plans. Floodplain Development Permits
based on the basis of approved plans and applications authorize only the use, arrangement, and
construction set forth in such approved plans and applications and no other use, arrangement, or
construction. Any use, arrangement, or construction at variance with that authorized shall be deemed a
violation of this chapter. The applicant shall be required to submit certification by a professional engineer
or land surveyor, as appropriate, registered in the State of Iowa, that the finished fill, structure floor
elevations, floodproofing, or other flood protection measures were accomplished in compliance with the
provisions of this chapter, prior to the use or occupancy of any structure.
170.05 ESTABLISHMENT OF ZONING (OVERLAY) DISTRICTS. The floodplain areas within the
jurisdiction of this chapter are hereby divided into the following districts:
1. Floodway (Overlay) District (FW) — those areas identified as Floodway on the Official Floodplain
Zoning Map;
2. Floodway Fringe (Overlay) District (FF) — those areas identified as Zone AE on the Official
Floodplain Zoning Map but excluding those areas identified as Floodway;
3. General Floodplain (Overlay) District (GF) — those areas identified as Zone A on the Official
Floodplain Zoning Map, and,
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The boundaries shall be as shown on the Official Floodplain Zoning Map. Within these districts, all uses
not allowed as pennitted uses are prohibited unless a variance to the terms of this chapter is granted after
due consideration by the Board of Adjustment.
170.06 FLOODWAY (OVERLAY) DISTRICT (FW).
1. Permitted Uses. All development within the Floodway District shall be permitted to the extent that
they are not prohibited by any other chapter (or underlying zoning district) and provided they meet
applicable performance standards of the Floodway District.
2. Performance Standards. All Floodway District uses allowed as a permitted use shall meet the
following standards:
A. No development shall be permitted in the Floodway District that would result in any increase in the
base flood elevation. Consideration of the effects of any development on flood levels shall be based upon
the assumption that an equal degree of development would be allowed for similarly situated lands.
B. All development within the Floodway District shall:
(1) Be consistent with the need to minimize flood damage.
(2) Use construction methods and practices that will minimize flood damage.
(3) Use construction materials and utility equipment that are resistant to flood damage.
C. No development shall affect the capacity or conveyance of the channel or floodway of any tributary
to the main stream, drainage ditch, or any other drainage facility or system.
D. Structures, buildings, recreational vehicles, and sanitary and utility systems, if permitted, shall meet
the applicable perfonnance standards of the Floodway Fringe District and shall be constructed or aligned
to present the minimum possible resistance to flood flows.
E. Structures, if permitted, shall have a low flood damage potential and shall not be for human
habitation.
F. Storage of materials or equipment that are buoyant, flammable, explosive, or injurious to human,
animal, or plant life is prohibited. Storage of other material may be allowed if readily removable from the
Floodway District within the time available after flood warning.
G. Watercourse alterations or relocations (channel changes and modifications) must be designed to
maintain the flood carrying capacity within the altered or relocated portion. In addition, such alterations
or relocations must be approved by the Department of Natural Resources.
1-1. Any fill allowed in the floodway must be shown to have some beneficial purpose and shall be
limited to the minimum amount necessary.
I. Pipeline river or stream crossings shall be buried in the streambed and banks or otherwise
sufficiently protected to prevent rupture due to channel degradation and meandering or due to the action
of flood flows.
170.07 FLOODWAY FRINGE (OVERLAY) DISTRICT (FF).
1. Permitted Uses. All development within the Floodway Fringe District shall be permitted to the extent
that they are not prohibited by any other chapter (or underlying zoning district) and provided they meet
applicable performance standards of the Floodway Fringe District.
2. Performance Standards. All development must be consistent with the need to minimize flood damage
and meet the following applicable performance standards. Until a regulatory floodway is designated, no
development may increase the Base Flood Elevation more than one (1) foot. Where 100-year flood data
has not been provided on the Flood Insurance Rate Map, the Iowa Department of Natural Resources shall
be contacted to compute such data. The applicant will be responsible for providing the Department of
Natural Resources with sufficient technical information to make such determination.
A. All development shall:
(1) Be designed and adequately anchored to prevent flotation, collapse, or lateral movement of the
structure.
(2) Use construction methods and practices that will minimize flood damage.
(3) Use construction materials and utility equipment that are resistant to flood damage.
B. Residential Structures. All new or substantially improved residential structures shall have the
lowest floor, including basement, elevated a minimum of one foot above the base flood elevation.
Construction shall be upon compacted fill which shall, at all points, be no lower than 1.0 ft. above the
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base flood elevation and extend at such elevation at least 18 feet beyond the limits of any structure erected
thereon. Alternate methods of elevating (such as piers or extended foundations) may be allowed where
existing topography, street grades, or other factors preclude elevating by fill. In such cases, the methods
used must be adequate to support the structure as well as withstand the various forces and hazards
associated with flooding.
All new residential structures located in areas that would become isolated due to flooding of surrounding
ground shall be provided with a means of access that will be passable by wheeled vehicles during the base
flood. However, this criterion shall not apply where the Administrator determines there is sufficient flood
warning time for the protection of life and property. When estimating flood warning time, consideration
shall be given to the criteria listed in 567-75.2(3), Iowa Administrative Code.
C. Non -Residential Structures. All new or substantially improved non-residential structures shall have
the lowest floor (including basement) elevated a minimum of one foot above the base flood elevation, or
together with attendant utility and sanitary systems, be floodproofed to such a level. When floodproofing
is utilized, a professional engineer registered in the State of Iowa shall certify that the floodproofing
methods used are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces
and other factors associated with the base flood; and that the structure, below the base flood elevation is
watertight with walls substantially impermeable to the passage of water. A record of the certification
indicating the specific elevation (in relation to North American Vertical Datum 1988) to which any
structures are floodproofed shall be maintained by the Administrator.
D. All New and Substantially Improved Structures.
(1) Fully enclosed areas below the "lowest floor" (not including basements) 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 rneet or exceed the following minimum criteria:
a. A minimum of two openings, with positioning on at least two walls, having a total net area of
not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
b. The bottom of all openings shall be no higher than one foot above grade.
c. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided
they permit the automatic entry and exit of floodwaters.
Such areas shall be used solely for parking of vehicles, building access and low damage potential
storage.
(2) New and substantially improved structures must be designed (or modified) and adequately
anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic
and hydrostatic loads, including the effects of buoyancy.
(3)New and substantially improved structures shall be constructed with electric meter, electrical
service panel box, hot water heater, heating, air conditioning, ventilation equipment (including ductwork),
and other similar machinery and equipment elevated (or in the case on non-residential structures,
optionally floodproofed to) a minimum of one foot above the base flood elevation.
(4)New and substantially improved structures shall be constructed with plumbing, gas lines, water/gas
meters and other similar service utilities either elevated (or in the case of non-residential structures,
optionally floodproofed to) a minimum of one foot above the base flood elevation or designed to be
watertight and withstand inundation to such a level.
E. Factory -Built Homes.
(1) All new and substantially improved factory -built homes, including those placed in existing
factory -built home parks or subdivisions, shall be elevated on a permanent foundation such that the lowest
floor of the structure is a minimum of one foot above the base flood elevation.
(2) All new and substantially improved factory -built homes, including those placed in existing
factory -built home parks or subdivisions, shall be 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. Anchorage systems may include, but are not limited to, use of over -the -top or frame ties
to ground anchors as required by the State Building Code.
F. Utility and Sanitary Systems.
(1) On -site wastewater disposal and water supply systems shall be located or designed to avoid
impairment to the system or contamination from the systern during flooding.
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(2) All new and replacement sanitary sewage systems shall be designed to minimize or eliminate
infiltration of flood waters into the system as well as the discharge of effluent into flood waters.
Wastewater treatment facilities (other than on -site systems) shall be provided with a level of flood
protection equal to or greater than one foot above the base flood elevation.
(3) New or replacement water supply systems shall be designed to minimize or eliminate infiltration
of flood waters into the system. Water supply treatment facilities (other than on -site systems) shall be
provided with a level of protection equal to or greater than one foot above the base flood elevation.
(4) Utilities such as gas or electrical systems shall be located and constructed to minimize or
eliminate flood damage to the system and the risk associated with such flood damaged or impaired
systems.
G. Storage of Materials and Equipment. Storage of materials and equipment that are flammable,
explosive, or injurious to human, animal, or plant life is prohibited unless elevated a minimum of one foot
above the base flood elevation. Other material and equipment must either be similarly elevated or (i) not
be subject to major flood damage and be anchored to prevent movement due to flood waters or (ii) be
readily removable from the area within the time available after flood warning.
H. Flood Control Structural Works. Flood control structural works such as levees, flood walls, etc.
shall provide, at a minimum, protection from the base flood with a minimum of three feet of design
freeboard and shall provide for adequate interior drainage. In addition, the Department of Natural
Resources shall approve structural flood control works.
I. Watercourse Alterations or Relocations. Watercourse alterations or relocations must be designed to
maintain the flood carrying capacity within the altered or relocated portion. In addition, the Department of
Natural Resources must approve such alterations or relocations.
J. Subdivisions. Subdivisions (including factory -built home parks and subdivisions) shall be consistent
with the need to minimize flood damages and shall have adequate drainage provided to reduce exposure
to flood damage. Development associated with subdivision proposals (including the installation of public
utilities) shall meet the applicable performance standards of this chapter. Subdivision proposals intended
for residential use shall provide all lots with a means of access which will be passable by wheeled
vehicles during the base flood. Proposals for subdivisions greater than five acres or 50 lots (whichever is
less) shall include base flood elevation data for those areas located within the Floodway Fringe (Overlay)
District.
K. Accessory Structures to Residential Uses.
(1) Detached garages, sheds, and similar structures that are incidental to a residential use are exempt
from the base flood elevation requirements where the following criteria are satisfied.
a. The structure shall be designed to have low flood damage potential. Its size shall not exceed 600
sq. ft. in size. Those portions of the structure located less than one foot above the BFE must be
constructed of flood -resistant materials.
b. The structure shall be used solely for low flood damage potential purposes such as vehicle
parking and limited storage. The structure shall not be used for human habitation.
c. The structure shall be constructed and placed on the building site so as to offer minimum
resistance to the flow of floodwaters.
d. The structure shall be firmly anchored to prevent flotation, collapse, and lateral movement
which may result in damage to other structures.
e. The structure's service facilities such as electrical and heating equipment shall be elevated or
floodproofed to at least one foot above the base flood elevation.
f. The structure's walls shall include openings that satisfy the provisions of Section
170.07(2)(D)(1) of this chapter.
(2) Exemption from the base flood elevation requirements for such a structure may result in
increased premium rates for flood insurance coverage of the structure and its contents.
L. Recreational Vehicles.
(1) Recreational vehicles are exempt from the requirements of Section 170.07(2)(E) of this chapter
regarding anchoring and elevation of factory -built homes when the following criteria are satisfied.
a. The recreational vehicle shall be located on the site for less than 180 consecutive days, and,
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b. The recreational vehicle must be fully licensed and ready for highway use. A recreational
vehicle is ready for highway use if it is on its wheels or jacking system and is attached to the site only by
quick disconnect type utilities and security devices and has no permanently attached additions.
(2) Recreational vehicles that are located on the site for more than 180 consecutive days or are not
ready for highway use must satisfy requirements of Section 170.07(2)(E) of his chapter regarding
anchoring and elevation of factory -built homes.
M. Pipeline River and Stream Crossings. Pipeline river and stream crossings shall be buried in the
streambed and banks, or otherwise sufficiently protected to prevent rupture due to channel degradation
and meandering.
N. Maximum Damage Potential Development. All new or substantially improved maximum damage
potential development shall have the lowest floor (including basement) elevated a minimum of one foot
above the elevation of the 500-year flood, or together with attendant utility and sanitary systems, be
floodproofed to such a level. When floodproofing is utilized, a professional engineer registered in the
State of Iowa shall certify that the floodproofing methods used are adequate to withstand the flood depths,
pressures, velocities, impact, and uplift forces and other factors associated with the 0.2 percent annual
chance flood; and that the structure, below the 0.2 percent annual chance flood elevation is watertight
with walls substantially impermeable to the passage of water. A record of the certification indicating the
specific elevation (in relation to North American Vertical Datum 1988) to which any structures are
floodproofed shall be maintained by the Administrator. Where 0.2 percent chance flood elevation data has
not been provided in the Flood Insurance Study, the Iowa Department of Natural Resources shall be
contacted to compute such data. The applicant will be responsible for providing the Department of
Natural Resources with sufficient technical information to make such determinations.
170.08 GENERAL FLOODPLAIN (OVERLAY) DISTRICT (FP).
1. Permitted Uses.
A. All development within the General Floodplain District shall be permitted to the extent that they are
not prohibited by other ordinances (or underlying zoning district) and provided they meet the applicable
performance standards of the General Floodplain District.
B. Any development which involve placement of structures, factory -built homes, fill or other
obstructions, storage of materials or equipment, excavation, or alteration of a watercourse shall be
reviewed by the Department of Natural Resources to determine (1) whether the land involved is either
wholly or partly within the floodway or floodway fringe and (ii) the base flood elevation. The applicant
shall be responsible for providing the Department of Natural Resources with sufficient technical
information to make the determination.
C. Review by the Iowa Department of Natural Resources is not required for the proposed construction
of new or replacement bridges or culverts where:
(1) The bridge or culvert is located on a stream that drains less than two square miles, and
(2) The bridge or culvert is not associated with a channel modification that constitutes a channel
change as specified in 567.71.2(2), Iowa Administrative Code.
2. Performance Standards
A. All development, or portions thereof, to be located in the floodway as determined by the
Department of Natural Resources shall meet the applicable provisions and standards of the Floodway
(Overlay) District Section 170.07.
B. All development, or portions thereof, to be located in the floodway fringe as determined by the
Department of Natural Resources shall meet the applicable provisions and standards of the Floodway
Fringe (Overlay) District Section 170.07.
170.09 APPOINTMENT AND DUTIES OF BOARD OF ADJUSTMENT.
1. Appointment and Duties of Board of Adjustment. A Board of Adjustment is here by established
which shall hear and decide (i) appeals and (ii) requests for variances to the provisions of the chapter, and
shall take any other action which is required of the Board.
2. Appeals. Where it is alleged there is any error in any order, requirement, decision, or determination
made by an administrative official in the enforcement of this chapter, the aggrieved party may appeal
such action. The notice of appeal shall be tiled with the Board of Adjustment and with the official from
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whom the appeal is taken and shall set forth the specific reason for the appeal. The official from whom
the appeal is taken shall transmit to the Board of Adjustment all the documents constituting the record
upon which the action appealed from was taken.
3. Variance. The Board of Adjustment may authorize upon request in specific cases such variances from
the terms of this chapter that will not be contrary to the public interest where, owning to special
conditions, a literal enforcement of the provisions of this chapter will result in unnecessary hardship.
Variances granted must meet the following applicable standards.
A. Variances shall only be granted upon: (i) a showing of good and sufficient cause, (ii) a
determination that failure to grant the variance would result in exceptional hardship to the applicant, and
(iii) a determination that the granting of the 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 codes or ordinances.
B. Variances shall not be issued within any designated floodway if any increase in flood levels during
the base flood would result. Consideration of the effects of any development on flood levels shall be
based upon the assumption that an equal degree of development would be allowed for similarly situated
lands.
C. Variances shall only be granted upon a determination that the variance is the minimum necessary,
considering the flood hazard, to afford relief.
D. In cases where the variance involves a lower level of flood protection for structures than what is
ordinarily required by this chapter, the applicant shall be notified in writing over the signature of the
Administrator that: (i) the issuance of a variance will result in increased premium rates for flood insurance
up to amounts as high as $25 for $100 of insurance coverage and (ii) such construction increases risks to
life and property.
E. All variances granted shall have the concurrence or approval of the Department of Natural
Resources.
4. Hearings and Decisions of the Board of Adjustment.
A. Hearings. Upon the filing with the Board of Adjustment of an appeal or a request for a variance the
board shall hold a public hearing. The board shall fix a reasonable time for the hearing and give public
notice thereof, as well as due notice to parties in interest. At the hearing, any party may appear in person
or by agent or attorney and present written or oral evidence. The board may require the appellant or
applicant to provide such information as is reasonably deemed necessary and may request the technical
assistance and/or evaluation of a professional engineer or other expert person or agency, including the
Department of Natural Resources.
B. Decisions. The board shall arrive at a decision on an appeal or variance within a reasonable time. In
passing upon an appeal, the board may, so long as such action is in conformity with the provisions of this
chapter, reverse or affirm, wholly or in part, or modify the order, requirement, decision, or determination
appealed from, and it shall make its decision, in writing, setting forth the findings of fact and the reasons
for its decision. In granting a variance, the board shall consider such factors as contained in this section
and all other relevant sections of this chapter and may prescribe such conditions as contained in Section
170.09(4)(B)(2).
(1) Factors Upon Which the Decision of the Board of Adjustment Shall be Based. In passing upon
applications for variances, the board shall consider all relevant factors specified in other section of this
chapter and:
a. The danger to life and property due to increased flood heights or velocities caused by
encroachments.
b. The danger that materials may be swept on to other land or downstream to the injury of others.
c. The proposed water supply and sanitation systems and the ability of these systems to prevent
disease, contamination, and unsanitary conditions.
d. The susceptibility of the proposed facility and its contents to flood damage and the effect of such
darnage on the individual owner.
e. The importance of the services provided by the proposed facility to the City.
f. The requirements of the facility for a floodplain location.
g. The availability of alternative locations not subject to flooding for the proposed use.
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h. The compatibility of the proposed use with existing development and development anticipated
in the foreseeable future.
i. The relationship of the proposed use to the comprehensive plan and floodplain management
program for the area.
j. The safety of access to the property in times of flood for ordinary and emergency vehicles.
k. The expected heights, velocity, duration, rate of rise, and sediment transport of the flood water
expected at the site.
1. The cost of providing governmental service during and after flood conditions, including
maintenance and repair of public utilities (sewer, gas, electrical, and water systems), facilities, streets, and
bridges.
m. Such other factors which are relevant to the purpose of this chapter.
(2) Conditions Attached to Variances. Upon consideration of the factors listed above, the Board of
Adjustment may attach such conditions to the granting of variances as it deems necessary to further the
purpose of this chapter. Such conditions may include, but not necessarily be limited to:
a. Modification of waste disposal and water supply facilities.
b. Limitation of periods of use and operation.
c. Imposition of operational controls, sureties, and deed restrictions.
d. Requirements for construction of channel modifications, dikes, levees, and other protective
measures, provided such are approved by the Department of Natural Resources and are deemed the only
practical alternative to achieving the purpose of this chapter.
e. Floodproofing measures shall be designed consistent with the flood protection elevation for the
particular area, flood velocities, duration, rate of rise, hydrostatic and hydrodynamic forces, and other
factors associated with the regulatory flood. The Board of Adjustment shall require that the applicant
submit a plan or document certified by a registered professional engineer that the floodproofing measures
are consistent with the regulatory flood protection elevation and associated flood factors for the particular
area.
5. Appeals to the Court. Any person or person, jointly or severally, aggrieved by any decision of the
Board of Adjustment may present to a court of record a petition, duly verified, setting forth that such
decision is illegal, in whole or in part, specifying the grounds of the illegality. Such petition shall be
presented to the court within 30 days after the filing of the decision in the office of the Board.
170.10 NONCONFORMING USES.
1. A structure or the use of a structure or premises which was lawful before the passage or amendment of
this chapter, but which is not in conformity with the provisions of this chapter, may be continued subject
to the following conditions:
A. If such use is discontinued for six consecutive months, any future use of the building premises shall
conform to this chapter.
B. Uses or adjuncts thereof that are or become nuisances shall not be entitled to continue as
nonconforming uses.
C. If any nonconforming use or structure is destroyed by any means, including flood, it shall not be
reconstructed if the cost is more than 50 percent of the market value of the structure before the damage
occurred, unless it is reconstructed in conformity with the provisions of this chapter. This limitation does
not include the cost of any alteration to comply with existing state or local health, sanitary, building or
safety codes or regulations or the cost of any alteration of a structure listed on the National Register of
Historic Places, provided that the alteration shall not preclude its continued designation.
2. Except as provided in Section 170.10(1)(B) any use which has been permitted as a variance shall be
considered a conforming use.
170.11 PENALTIES FOR VIOLATION. Violations of the provisions of this chapter or failure to
comply with any of the requirements (including violations of conditions and safeguards established in
connection with grants 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
$500.00 or imprisoned for not more than 30 days. Each day such violation continues shall be considered a
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separate offense. Nothing herein contained shall prevent the City from taking such other lawful action as
is necessary to prevent or remedy violation.
170.12 AMENDMENTS. The regulations and standards set forth in this chapter may from time to time
be amended, supplemented, changed, or repealed. No amendment, supplement, change, or modification
shall be undertaken without prior approval of the Department of Natural Resources.
Section 2. Repealer. All ordinances or parts of ordinances in conflict with the
provisions of this ordinance are hereby repealed.
Section 3. Severability Clause. If any section, provision or part of this ordinance shall
be adjudged invalid or unconstitutional, such adjudication shall not affect the validity of the
ordinance as a whole or any section, provisions or part thereof not adjudged invalid or
unconstitutional.
Section 4. Effective Date. This ordinance shall be in effect from and after its final
passage, approval and publication as provided by law.
Passed by the Council the 21 It day of November, 2022, and approved this 21 It day of November,
2022.
Attest:
C/�j����✓r/vry CSi 'l
Rebecca D. Schuett, City Clerk
Courtney Clarke, Mayor
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