HomeMy WebLinkAbout~Master - Text Amendment regarding the new Flood Plain Maps, updated definitions, and amended terminology used in Chapter 9 of the Ames Municipal Code ORDI
NANCE NO.4422
AN ORDINANCE TO AMEND THE MUNICIPAL CODE OF
THE CITY OF AMES, IOWA,BY AMENDING CHAPTER 9
SECTION 9.1(3)(b)(c),9.2(2)(4),9.3(3),9.4(2)(b)(e)(g),
(3)(a)(b)(c)(e),9.5(2)(b)(c)(h)(i)(k)(i)(c),9.6(1)(g)(2),
9.7(I)(b)(iii)(2)(v)(vi),(e),(3)(e)(ii)(a)(7)(8)(9),9.7(3)(e)(ii)(b)(5)(h),
9.8(1)(a)(e)(2)(d(3)(a)(e),9.11 (2)(12)(14)(16)(27)(29)AND
ENACTING A NEW SECTION 9.6(4)(a)(b)(c)(1)(2),(5)(a)(b),
9.11(34)(35)(36)(37)(38)THEREOF,FOR THE PURPOSE OF
ADOPTING NEW FLOOD MAPS,UPDATE DEFINITIONS
AND AMEND TERMINOLOGY; REPEALING ANY AND ALL
ORDINANCES OR PARTS OF ORDINANCES IN CONFLICT
TO THE EXTENT OF SUCH CONFLICT; PROVIDING A
PENALTY; AND ESTABLISHING AN EFFECTIVE DATE.
BE IT ENACTED,by the City Council for the City of Ames, Iowa,that:
Section One. The Municipal Code of the City of Ames, Iowa shall be and the same is hereby
amended by enacting Chapter 9 as follows:
"Sec.9.1.STATUTORY AUTHORIZATION,FINDINGS OF FACT,AND PURPOSE.
(3) Purpose. It is the purpose of this ordinance to promote the public health, safety, and general
welfare by minimizing those flood losses described in Section 9.1(2)with provisions designed to:
(b) Restrict or prohibit development which is dangerous to health, safety or property in times of
flood or which cause excessive increases in flood heights or velocities.
(c) Require that development vulnerable to floods, including public utilities which serve such
development, be protected against flood damage at the time of initial construction or substantial
improvement.
Sec.9.2.GENERAL PROVISIONS.
•• (2)Establishment of Official Flood Plain Zoning Map.The Story County,Iowa and
Incorporated Areas Flood Insurance Rate Map(FIRM),City of Ames,Panels 19169C0135F,0137G,0139G,
0141G,0142G,0143G,0144G,0155F,0161F,0162F,0163G,0164F,0168F,0170F,0256G,0257G,0276F,
0277F,dated January 15 2021,which were prepared as part of the Flood Insurance Study for Story County
and digital FIRM equivalent are hereby adopted by reference and declared to be the Official Floodplain
Zoning Map.
•. (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.
Sec.9.3. ESTABLISHMENT OF ZONING OVERLAY DISTRICTS.
. (3) General Flood Plain Overlay District—The General Flood Plain Overlay District includes the
areas shown as"Zone A"on the Official Flood Plain Zoning Map Within these districts,all development not
allowed as permitted development are prohibited unless a variance to the terms of this ordinance is granted
after due consideration by the Zoning Board of Adjustment.
Sec.9.4. FLOODWAY OVERLAY DISTRICT.
(1)Permitted Uses. The following uses shall be permitted within the Floodway Overlay District to
the extent they are not prohibited by any other ordinance or underlying zoning district regulation, and
provided they do not include placement of habitable structures, factory-built homes, fill or other obstruction
the storage of materials or equipment,excavation,or alteration of a watercourse(except as needed for public
infrastructure):
(a)Agricultural uses such as general farming,pasture,grazing,outdoor plant
nurseries,horticulture,viticulture,truck farming,forestry,sod farming,and wild crop harvesting.
(b)Signs,billboards,utility transmission lines and pipelines.
(c)Private and public recreational uses such as golf courses,tennis courts,
driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife and
nature preserves, game farms, fish hatcheries, shooting preserves, target ranges, trap and skeet ranges,
hunting and fishing areas,hiking and horseback riding trails,and non-habitable structures accessory to them
that meet the applicable Floodway Overlay District Performance Standards.
(d)Residential accessory uses such as lawns,gardens and play areas.
(e)Grading provided there is no change of surface topography of more than one
foot and no fill is introduced into the Floodway.
(f)Such other open-space uses similar in nature to the above uses.
(g)Public infrastructure such as bridges;roads;trails;culverts;fill,excavation or
grading;channel changes,relocations or placement of riprap or similar material;provided that any required
permits from the Iowa Department of Natural Resources or Army Corps of Engineers have been approved.
Such uses must also meet the applicable provisions of the Floodway Overlay District Performance Standards.
This also includes any activity defined as maintenance under the nationwide permit issued by the Army Corps
of Engineers.
(2) Development Uses. The following uses developments which involve structures (temporary or
permanent), fill, or storage of materials or equipment may be permitted only upon issuance of a Major Site
Development Plan as provided for in Section 29.1103. Such developments must also meet the applicable
provisions of the Floodway Overlay District Performance Standards.
(a)Transient commercial uses such as circuses,carnivals, flea markets,and
similar transient enterprises.
(b)Permanent commercial development such as drive-in theaters,new and
used car lots,and roadside stands.
(c)Borrow pits,storm water detention and retention areas,and extraction of
sand,gravel,and other materials.
(d)Marinas,boat rentals,docks,piers,wharves.
(e)Accessory development such as loading areas,driveways and parking areas.
(f)Grading, in which the surface topography may be increased greater than one
foot.
(g)Other development similar in nature to development described as
permitted development or listed development, which are consistent with the performance standards of
Subsection(3)below and the general spirit and purpose of this ordinance.
(3) Performance Standards. All Floodway Overlay District development allowed as a Permitted
Development shall meet the following standards:
(a)No development shall be permitted in the Floodway Overlay District that
would result in any Increase in the base flood elevation level.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.Evidence required will be a hydraulic study performed by a licensed professional
engineer for the area of drainage involved.
(b)All development within the Floodway Overlay District shall:
(i)Be consistent with the need to minimize flood damage.
(ii)Use construction methods and practices that will minimize and resist
flood damage.
(iii)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 or any tributary to the main stream,drainage ditch,or any other drainage facility or system.
(d)Structures,buildings and sanitary and utility systems, if permitted,shall meet
the applicable performance standards of the Floodway Fringe Overlay 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.
Sec.9.5. FLOODWAY FRINGE OVERLAY DISTRICT.
(1)Permitted Uses. All uses within the Floodway Fringe Overlay District shall be permitted to the
extent that they are not prohibited by any other ordinance or underlying zoning district and provided they
meet applicable performance standards of the Floodway Fringe Overlay District.
(2)Performance Standards.All development must be consistent with the need to
minimize flood damage and shall 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. The
applicant will be responsible for providing the Department of Natural Resources with sufficient technical
information to make such a determination.
(a)All structures shall
(i)be adequately anchored to prevent flotation,collapse or lateral
movement of the structure,
(ii)be constructed with materials and utility equipment resistant to flood
damage,and
(iii)be constructed by methods and practices that minimize flood
damage.
(b)Residential Structure. All new or substantially improved residential structures
shall have the lowest floor, including basements,elevated a minimum of three(3)feet above the base flood
elevation level. Construction shall be upon compacted fill which shall, at all points, be no lower than three
(3)feet above the base flood elevation level and extend at such elevation at least 18 feet beyond the limits of
any structure erected thereon. Alternate methods of elevating (such as piers) may be allowed, subject to
favorable consideration by the Zoning Board of Adjustment and issuance of a Conditional Use Permit,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 buildings shall be provided with a means of access which will be passable by
wheeled vehicles during the base flood elevation.
(c)Non-residential Structure.All new and substantially improved non-residential
structures shall have the lowest floor(including basement)elevated a minimum of three(3) feet above the
base flood elevation level,or together with attendant utility and sanitary systems,be floodproofed to such a
level. When floodproofing is utilized,a professional engineer licensed 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 elevation level,and that the structure,below the
base flood elevation level, is watertight with walls substantially impermeable to the passage of water. A
record of the certification indicating the specific elevation to which any structures are floodproofed shall be
maintained by the Flood Plain Administrator.
•. (h)No development shall affect the capacity or conveyance of the channel or
floodway of any tributary to the main stream,drainage ditch,or other drainage facility or system. In addition,
the Department of Natural Resources must approve any alteration or relocation of any stream.
(i)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 Ordinance. Subdivision proposals
intended for residential development shall provide all lots with a means of vehicular access that will remain
dry during occurrence of the base flood. Proposed subdivision plats greater that five (5)acres or fifty(50)
lots(whichever is fewer)shall include base flood elevation data for those areas located within the Floodway,
Floodway Fringe,or General Floodway Overlay Districts on the preliminary plat and final plat.
(k)For all new and substantially improved structures:
(i)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 licensed professional engineer or meet or exceed the following minimum criteria:
a. A minimum of two openings 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,that 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.
Sec.9.6.GENERAL FLOOD PLAIN OVERLAY DISTRICT(FP).
(1) ...
(g)Public infrastructure such as bridges;roads;trails;culverts;fill,excavation or
grading;channel changes,relocations or placement of riprap or similar material;provided that any
required permits from the Iowa Department of Natural Resources or Army Corps of Engineers have been
approved. Such development must also meet the applicable provisions of the Floodway Overlay District
Performance Standards.This also includes any activity defined as maintenance under the nationwide permit
issued by the Army Corps of Engineers.
.. (2)Performance Standards.
(a)All conditional uses,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.
(b) All conditional uses, or portions thereof, to be located in the floodway fringe as
determined by the Department of Natural Resources shall meet the applicable standards of the Floodway
Fringe Overlay District.
(3)Permitted Uses
a. All development within the General Floodplain District shall be permitted to the
extent that
they are not prohibited by any other ordinance (or underlying zoning district) and provided they meet the
applicable performance standards of the General Floodplain District.
b. Any development which involves 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 (i) 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(2)
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.
(4)Performance Standards
d. 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.
e. 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.
Sec. 9.7. ADMINISTRATION
(1)Appointment,Duties and Responsibilities of Flood Plain Administrator
(a)The Flood Plain Administrator(the Administrator)shall be the Director of the
Department of Planning and Housing or his/her designee and shall administer and enforce 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:
. (iii)Record and maintain a record of:
a.the elevation(in relation to the appropriate vertical datum)of the
lowest habitable floor of all new or substantially improved structure or
b.the elevation to which new or substantially improved structures have
been floodproofed.
..• (2)Flood Plain Development Permit.
(a)Permit Required.A Flood Plain Development Permit issued by the Administrator
shall be secured prior to initiation of any flood plain development. Development is defined in Section 9.11
(b)Application for Permit.Application for a Flood Plain Development Permit shall be
made on forms supplied by the Administrator and shall include the following information:
(v)Elevation of the lowest floor(including basement)of a structure or of the
level to which a building is to be floodproofed.
(vi)For a structure being improved or rebuilt,the estimated cost of
improvements and market value of the building prior to the improvements.
(e)The applicant shall be required to submit certification by a professional engineer or
land surveyor, as appropriate, licensed 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 Ordinance,prior to the use or occupancy of any structure.
(3)Conditional Uses,Appeals, and Variances.
(e)Hearings and Decisions of the Zoning Board of Adjustment.
(ii)Decisions.The Board shall arrive at a decision on a Conditional Use,
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 ordinance,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 Conditional Use or Variance
the Board shall consider such factors as contained in this section and all other relevant sections of this
ordinance and may prescribe such conditions as described below.
a. Factors Upon Which the Decision of the Board Shall be Based. In
passing upon requests for Conditional Uses or Variances,the Zoning Board shall consider all relevant factors
specified in other sections of this ordinance and:
7.The availability of alternative locations not subject to
flooding for the proposed development.
8.The compatibility of the proposed development with
existing development and development anticipated in the foreseeable future.
9.The relationship of the proposed development to the
comprehensive plan and flood plain management program for the area.
b. Conditions attached to Conditional Uses or Variances. Upon
consideration of the factors listed above,the Board may attach such conditions to the granting of Conditional
Uses or Variances as it deems necessary to further the purpose of this ordinance. Such conditions may
include,but are not limited to:
5.Floodproofing measures shall be designed consistent with the
flood protection elevation for the particular area, flood velocities, durations, rate of rise, hydrostatic and
hydrodynamic forces, and other factors associated with the regulatory flood. The Zoning Board of
Adjustment shall require that the applicant submit a plan or document certified by a licensed professional
engineer that the floodproofing measures are consistent with the regulatory flood protection elevation and
associated flood factors for the particular area. Such floodproofing measures may include, but are not
necessarily limited to the following:
(h)Pumping facilities or comparable practices for
subsurface drainage systems for a structure to relieve external foundation wall and basement flood pressures.
See.9.8. NONCONFORMING USES.
(1) In the Floodway Overlay District. When located in the Floodway Overlay District, a structure,
or the use of a structure, or the use of land,which was lawful before July 16,2004,but is not in conformity
with the provisions of this ordinance,may be continued subject to the following conditions:
(a)No use shall be expanded or enlarged to cover more lot area,or changed to
another use, unless that use is a permitted use.
. (e)If a nonconforming use is discontinued for twelve(12)consecutive months,any future
use of the structure or premises shall conform to this ordinance.
(2)In the Floodway Fringe Overlay District. When located in the Floodway Fringe Overlay
District,a structure,use of a structure or the use of land which was lawful before July 16,2004,but is not in
conformity with the provisions of this ordinance,may be continued subject to the following conditions:
(d)If a nonconforming use is discontinued for twelve(12)consecutive months,any
future use of the structure or premises shall conform to this ordinance.
(3) In the General Flood Plain Overlay District. When located in the General Flood Plain Fringe
Overlay District,a structure,use of a structure or the use of land which was lawful before July 16,2004,but
is not in conformity with the provisions of this ordinance, may be continued subject to the following
conditions:
(a)No use shall be expanded or enlarged to cover more lot area,or changed to
another use,unless that use is a permitted use.
(e)If a nonconforming use is discontinued for twelve(12)consecutive
months,any future use of the structure or premises shall conform to this ordinance.
Sec.9.11. DEFINITIONS.
BASE FLOOD ELEVATION (BFE)-The elevation floodwaters would reach at a particular site during the
occurrence of a base flood event.
FLOOD INSURANCE STUDY(FIS)-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
FLOODPROOFING-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.
FLOODWAY FRINGE-Those portions of the Special Flood Hazard Area outside the floodway.
SPECIAL FLOOD HAZARD AREA (SFHA) - 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. These Zones apply to areas subject to one percent or greater chance of flooding in any given
year
STRUCTURE-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/or other similar uses.
New Definitions
APPURTENANT STRUCTURE- 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.
FIVE HUNDRED (500)YEAR FLOOD - A flood, the magnitude of which has a two-tenths (0.2)percent
chance of being equaled or exceeded in any given year or which,on average,will be equaled or exceeded at
least once every five hundred(500)years.
FLOODPLAIN MANAGEMENT-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.
HIGHEST ADJACENT GRADE-The highest natural elevation of the ground surface prior to construction
next to the proposed walls of a structure.
NEW FACTORY-BUILT HOME PARK OR SUBDIVISION-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 effective date of the first
floodplain management regulations adopted by the community."
Section Two. Violation of the provisions of this ordinance shall constitute a municipal infraction
punishable as set out by law.
Section Three. All ordinances, or parts of ordinances, in conflict herewith are hereby repealed to
the extent of such conflict, if any.
Section Four. This ordinance shall be in full force and effect from and after its passage and
publication as required by law.
Passed this 241 day of November,2020.
Diane R. Voss,City Clerk Io4n A.Itaila,Mayor