HomeMy WebLinkAboutCity Council Ordinance 1978-10CITY OF PLYMOUTH
ORDINANCE NO. 78-10
AN ORDINANCE AMENDING THE ZONING ORDINANCE TO CLASSIFY
CERTAIN LANDS WITHIN THE CORPORATE LIMITS AS FLOOD PLAIN
DISTRICTS
THE CITY COUNCIL. OF THE CITY OF PLYMOUTH DOES HEREBY ORDAIN
AS FOLLOWS:
Section 1. Amendment of Ordinance. Ordinance No. 78-2
of the City of Plymouth, adopted January 9, 1978 and known as
the Plymouth Zoning Ordinance is hereby amended by changing
Section 6 and the classifications on the City of Plymouth
Zoning Map as follows:
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SECTION 6 FLOOD PLAIN OVERLAY DISTRICT
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Subdivision 1. Purpose.
The legislature of the State of Minnesota has in Minnesota
Statutes 1969, D.104 delegated the responsibility to local
governmental units to adopt regulations designed to minimize
flood losses. This Section of the Plymouth Zoning Ordinance
is responsive to the cited Legislative Mandate as administered
by the Commissioner of the Minnesota Department of Natural
Resources and _he provisions of the Storm Drainage Plan of the
City of Plymouch.
Subdivision 2. Intent.
The regulations contained in this District are intended to guide j
developments in flood plain meas consistent with potential
flood threats and City land needs. Unwise use of flood plain
lands causes loss of life and property, disruption of commerce
and governmental services, unsanitary conditions, and interrup-
tion of transportation and communications. Sound land use
development can reduce damages, expenses, and inconveniences
and assure that City lands are put to their most appropriate use.
This district is based upon Flood Insurance Study, City of
Plymouth, Minnesota, and all Flood Insurance Rate Maps, Flood
Boundary and Floodway Maps and Flood profiles attached thereto,
dated November, 1977, and published by the United States
Department of Housing and Urban Development. This Study contains
data consistent with standards established by the Minnesota
Department of Natural Resources. (The Bassett's Creek Watershed
Management Plan dated February, 1972, which contains data
consistent with standards established by the Minnesota Depart-
ment of Natural Resources for delineation of the General Flood
Plain District.) The Regulations contained within this Overlay j
District are intended to manage areas suitable for development
of varying types as permitted in the Underlying Zoning District.
Subdivision 3. General Provisions.
1. Lands to Which Section Applies and Establishment of
Regulatory Flood Protection Elevation
2.
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A. This Section shall apply to all lands within the
jurisdiction of the City of Plymouth located
within the Floodway, Flood Fringe and General
Flood Plain District. The Flood Insurance Study
for the City of Plymouth referenced in Subdivision
2 above shall be attached to and considered a part
of the Official Zoning Map and this Ordinance.
B. The regulatory flood protection elevation and
necessary floodway areas shall be based first
on any applicable data contained in the Flood
Insurance Study for Plymouth referenced in Sub=
division 2 above. In those areas designed as
Unnumbered A Zones, the regulatory flood pro-
tection elevation and necessary floodway areas
shall be established by the City Council consistent
with the methods specified in Subdivision 8 of this
ordinance.
Rules for Interpretation of District Boundaries. The
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Boundaries of the Flood Plain District shall be deter-
mined by scaling distances on the Official Zoning Map.
Where interpretation is needed as to the exact location
of the boundaries of the district as shown on the Offici
r
all
Zoning Map, as for example where there appears to be a
conflict between a mapped boundary and actual field
conditions, the City Council shall make the necessary
interpretation based upon the applicable flood profile
(Plates 01P -05P) or Base Flood Elevation data contained
in the Floodway Data Table (Table 2) in the Flood In-
surance Study, City of Plymouth, Minnesota. The person
contesting the location of the district boundary shall
be given a reasonable opportunity to present his case to�
the Council and to submit his own technical evidence
if he so desires.
Warning and Disclaimer of Liability. This Ordinance
does not imply that areas outside the General Flood
Plain District boundaries or land uses permitted within
such district will be free from flooding or flood damages.
This Ordinance shall not create liability on the part
of the City of Plymouth or any officer or employee
thereof for any flood damages that result from reliance
on this Ordinance or any administrative decision law-
fully made thereunder.
Subdivision. 4. Fstablishment of Zoning Districts.
The flood plain areas within the jurisdiction of this ordinance
are hereby divided into three Districts: Floodway District (FW),1
Flood Fringe District (FF), and General Flood Plain District
(GFP).
1. Floodway District. The Floodway District shall include
those areas designated as floodway in the Flood In-
surance Study.
2. Flood Fringe District. The Flood Fringe District shall
include those areas designated floodway fringe in the
Flood Insurance Study.
3. General Flood Plain District. The General Flood Plain
District shall include those areas designa'ced as
unnumbered A Zones by the Flood Insurance Rate Map.
The boundaries of those districts shall be generally as shown on l
the Official Zoning Map and the final determination to the
district boundaries will be based on all applicable data in
the Flood Insurance Study for Plymouth. Within these districts,
all uses not allowed as permitted uses or permissable as
conditional uses shall be prohibited,
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Subdivision S. Floodway District (FW).
1. Permitted Uses. The following uses have a low flood damage
potential and do not obstruct flood flows, These uses shall
be permitted within the Floodway District to the extent
that they are not prohibited by any other ordinance and
provided they do not require structures, fill, or storage
of materials or equipment. In addition, no use shall
adversely affect the capacity of the channels or floodways
or any tributary to the main stream or of any drainage
ditch, or any other drainage facility or system.
A. Agricultural uses such as general farming, pasture,
grazing, outdoor plant nurseries, horticulture, truck
farming, forestry, sod farming, and wild crop harvest-
ing.
B. Industrial -Commercial uses such as loading areas,
parking areas, and airport landing strips.
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,
and hiking and horseback riding trails,
D. Residential uses such as lawns, gardens, parking areas,
and play areas.
2. Conditional Uses. The following open space uses require
accessory structures (temporary or permanent), or fill
or storage of materials or equipment. These uses may be
permitted in the Floodway District only after the issuance
of a Conditional Use Permit as provided in Subdivision 8
of this Ordinance. These uses are also subject to the
provisions of Subdivision 5, paragraph 3, which applies
to all floodway Conditional Uses.
A. Structures accessory to open space.
B. Placement of fill.
C. Extraction of sand, gravel, and other materials.
D. Marinas, boat rentals, docks, piers, wharves, and water
control structures.
E. Railroads, streets, bridges, utility transmission
lines, and pipelines.
F. Storage yards for equipment, machinery, or materials.
G. Other uses similar in nature to uses described in Sub-
division 5, paragraph la and paragraph 2 which are
consistent with the provisions set out in Subdivision
1 and 5 of this ordinance.
3. Standards for Floodway Conditional Uses
A. All Uses. No structure (temporary or permanent), {
fill (including fill for roads and Levees), deposit, }�
obstruction storage of materials, or equipment, or i
other uses may be allowed as Conditional Uses which,
acting alone or in combination with existing or
reasonably anticipated future uses, adversely affects
the capacity of the floodway or increases flood heights.
In addition, all floodway Conditional Uses shall be
subject to the standards contained in Subdivision 8,
paragraph S and the following standards:
B. Fill
1) Any fill deposited in the floodway shall be no
more than the minimal amount necessary to conduct
a Conditional Use listed in Subdivision 5, paragraph
2. Generally, fill shall be limited to that needed
to grade or landscape for that use and shall not
in any way further obstruct the flow of flood waters,
2) Spoil from dredging or sand and gravel operations
shall not be deposited in the floodway unless it
can be done in accordance with (1) of this paragraph.
3) Fill shill be protected from erosion by vegetative
cover.
C. Accessory Structures (temporary or permanent) perTiitted
as Conditional Uses by Subdivision 5, paragraph 2, A.
1) Accessory structures shall not be designed for
human habitation.
2) Accessory structures shall have a low flood dama„e
potential.
3) Accessory structures, if permitted, shall be
constructed and placed on the building site so as
to offer the minimum obstruction to the flow of
flood waters,
a) Whenever possible, structures shall be con-
structed with the longitudinal axis parallel
to the direction of the flood flow, and,
b) So far as practicable, structures shall be
placed approximately on the same flood flow
lines as those of adjoining structures.
4) Accessory structure shall be floodproofed in ac-
cordance with the State Building Code.
D. Storage of Materials and Equipment.
1) The storage or processing of materials that are in
time of flooding buoyant, flammable, explosive,or
could be injurious to human, animal, or plant life
is prohibited.
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E. Structural Work for Flood Control, Structuralworks
for flood control such as dams, levees, dikes, and
floodwalls.shall be allowed only upon issuance of a
Conditional Use Permit. In addition, any proposed
work in the beds of public waters which will change
the course, current, or cross-section of the waters
t# shall be'subject to the provisions of Minnesota
Statutes 1976, c. 105, and other applicable statutes.
Subdivision 6. Flood Fringe' District (PF),
1. Permitted Uses. The following uses shall be permitted uses<:
within the Flood Fringe District to the extent that they
are not prohibited by any other ordinance
A. Any use permitted in Subdivision 5, paragraph 1.
B. Accessory structures provided they comply with the
provision of Su?,division 5'paragraph 3c of this
ordinance.
C. Residence and other structures constructed on fill so
that,the basement floor or first floor, if there is
no basement, is at or above the regulatory flood
protection elevation. The finished fill elevation,
shall be ,no lower than one (1) foot below the regula-
tory flood protection elevation and shall extend at
such elevation at least fifteen (l5} feet beyond the
limits of any structure or building erected, thereon.
Fill shall be compacted and the slopes shall be protecte`l
by rip rap or vegetative covering,
- No use shall be permitted which will adversely' affect
the capacity of channels or floodways of any tributary
to the main stream, or of any drainage ditch, or any
drainage facility or system.
2. Conditional Uses. Uther uses are permitted only upon-arpli-.
cation to thb Zoning Administrator and the issuance of a
Conditional Use Permit as; provided, by this Ordinance and
subject to the following provisions:
''Ai Residences. Where existing streets, utilities, and
small lot sizes.pteclude the use of fill, other methods
of elevating the first floor (including basements)
above the regulatory:'flood protection elevation may be
authorized provided that, the residence is floodproo£ed
B.
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Commerical Structures. Commercial, manufacturing, and
industrial structures shall ordinarily be elevated on
fill so that their first floor (including basement)
is above the regulatory flood protection elevation but
may in special circumstances be floodproofed in ac-
cordance with the State Building Code. Structures
that are not elevated to above the regulatory flood
protection elevation shall be floodproofed to FP -1
or FP -2 classification as defined by the State Building
Code. Structures floodproofed to FP -3 or FP -4 classi-
fication shall not be permitted.
3. Standards for Flood Frinme Uses.
A. Residential Uses. Residences that do not have vehicular
access at or above an elevation not more than two feet
below the regulatory flood protection elevation shall
not be permitted unless granted a variance by the Board
of Adjustment. In granting a variance, the Board shall
specify limitations on the period of use or occupancy of
the residence.
B. Commercial Uses. Accessory land uses, such as yards,
railroad tracks, and parking lots may be at elevations
lower than the Regulatory Flood Protection Elevation.
However, a permit for such facilities to be used by the
general public shall not be granted, in the absence of a
flood warning system that provides adequate time.for
evacuation if the area is inundated to a depth greater
than two feet or subject to flood velocities greater
than four feet per second upon the occurence of the
regional flood.
C. Manufacturing and Industrial Uses. Measures shall be
taken to minimize interference with normal plant
operations especially for streams having protracted
flood durations. Certain accessory land uses such as
yards and parking lots may be at lower elevations
subject to requirements set out above. In considering
permit applications, due consideration shall be given
to needs of an industry whose business requires that
it be located in flood plain areas.
Subdivision 7. General Flood Plain District (GFP).
1. Permitted Uses, Permitted uses shall include those uses
permitted by Subdivision 5, paragraph 5, of this Ordinance.
sional engineer, registered architect or registered
land surveyor that the finished fill and building ti
elevations were accomplished in compliance with the
provisions of this ordinance. Floodproofing measures
shall be certified by a registered professional
engineer or registered architect.
D. State and Federal Permits. Prior to granting a Use
Permit or processing an application for a Conditional
Use Permit or Variance in the flood plain districts,
the Zoning Administrator shall determine that the
applicant has obtained all necessary State and Federal
Permits.
E. Record of First Floor Elevation. Thu Zoning Administra-
tor shall maintain a record of the elevation of the
first floor (including basement) of all new structures
or additions to existing structures in the flood plain
districts. The Zoning Administrator shall also
maintain a record of the elevations to which structures
or additions to structures are floodproofed.
F.
Subdivisions:
No land shall be subdivided which is held unsuitable !
by the City Council for reason of flooding, inadequate
drainage, or inadequate water supply or sewage treat- j
ment facilities. 411 lots within the flood plain
districts shall c..ntain a building site at or above
the regulatory flood protection elevation. All sub-
divisions shall have water and sewage disposal facilities
that comply with the provisions of this Ordinance and
have road access no lower than two feet below the
regulatory flood protection elevation. In the General `
Flood Plain District, applicants shall provide infor-
mation required in Subdivision 8, Paragraph 3, and the
subdivision shall be evaluated in accordance with the
procedures therein.
G. Public Utilities. All public utilities and facilities
such as gas, electrical, sewer, and water supply systems
to be located in the flood plain shall be floodproofed
in accordance with the State Building Code or elevated
to above the Regulatory Flood Protection Elevation.
H. Railroads, Roads, and Bridges. Railroad tracks, roads,
and bridges to be located within the floodway shall
comply with this Ordinance. In all flood plain
f _
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districts, elevation to the regulatory flood protection
elevation shall be provided where failure or interruption
of these transportation facilities would result in danger'
to the public health or safety or where such facilities
are essential to the orderly functioning of the area.
Minor auxiliary roads and railroads may be constructed
at a lower elevation where failure or interruption of
service would not endanger the public health or safety.
1. Water Supply and Waste Disposal Systems, Within all
flood plain districts, all new or replacement water
supply systems must be designed to minimize or
eliminate infiltration of flood waters into the system.
Within all flood plain districts, (1) require new and
replacement sanitary sewage systems to be designed to
minimize or eliminate infiltration of flood waters into
the systems and discharges into the systems into flood
waters and (2) on-site waste disposal systems to be
located to avoid impairment to them or contamination
from them during flooding.
J. Mobile Homes. Mobile homes as defined by this Ordinance
shall be prohibited as a permitted, accessory or
conditional use in any of the flood plain overlay
districts as defined by this Ordinance,
2. Board of Adjustment.
A. Variances. No variance from the terms of this Section
shall have the effect of allowing in any district uses
prohibited in that district, permit a lower degree of
flood protection than the flood protection elevation for
the particular area, or permit standards lower than
those required by State law,
B. Hearings and Decisions. The Zoning Administrator shall
submit to the Commissioner of Natural Resources a copy
of the application for the proposed Variances or
Conditional Uses of this Section sufficiently in advance
to that the Commissioner of Natural Resources will
receive at least ten days notice of the hearing. A copy
of all decisions granting Variances or Conditional Use
Permits of this Section shall be forwarded to the
Commissioner of Natural Resources within ten days of {
such action.
s.
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Procedures for Evaluating Proposed Conditional Uses Within
the General Flood Plain District.
A. Upon receipt of an application for a Conditional Use
Permit for a use within the General Flood Plain District
the applicant shall be required to furnish such of the
following information as is deemed necessary by the
City Council for the determination of the regulatory j
flood protection elevation and whether the proposed j
use is the floodway or the flood fringe.
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1) A typical valley cross-section showing the channel
of the stream, elevation of land areas adjoining
each side of the channel, eros; -sectional areas
to be occupied by the proposed development, and
2)
high water information.
Plan (surface view) showing elevations or contours
of the ground; pertinent structure, fill, or storage
elevations, size, location; and spatial arrangement
of all proposed and existing structures on the site;
location and elevations of streets; photographs
showing existing land uses and vegetation upstream
and downstream; and soil type. )
3) Profile showing the slope of the bottom of the chan-
nel or flow line of the stream for at least 500
feet in either direction from t.a proposed develop-
ment.
B. One copy of the above information shall be transmitted
to a designated engineer or other expert person or
agency for technical assistance in determining whether
the proposed use is in the floodway or flood fringe
and to determine the regulatory flood protection eleva-
tion. Procedures consistent with Minnesota Regulations
NR 86-87 shall be followed in this expert evaluation.
The designated engineer or expert shall:
1) Estimate the peak discharge of the regional flood.
2) Calculate the water surface profile of the regional
flood based upon a hydraulic analysis of the stream
channel and overbank areas.
3) Compute the floodway necessary to convey the regio.ia]
flood without increasing flood stages more than 0.5
feet. An equal degree of encroachment on both sides
of the stream within the reach shall be u,zsumed.
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j� C. Based on the technical evaluation of the d esignatekl
j engineer of expert, the City Council shall determine
j whether the proposed use is in the floodway or flood
�i fringe and the regulatory flood protection elevation
at the site.
4. Procedures to be followed by the City Council in Passing
on Conditional Use Permit Applications Within all Flood
Plnin Dictrirtq.
A. Require the applicant to furnish such of the following
information and additional information as deemed
necessary by the City Council for determining the
suitability of the particular site for the proposed
use:
1) Plans in triplicate drawn to scale showing the
nature, location, dimensions, and elevation of
the lot, existing or proposed structures, fill,
storage of materials, floodproofing measures,
and the relationship of the above to the location
of the channel.
2) Specifications for building construction and
materials, floodproofing, filling, dredging,
grading, channel improvement, storage of
materials, water supply and sanitary facilities
B. Transmit one copy of the information described in
subsection A (1) and (2) to a designated engineer or
other expert person or agency for technical assistance,
where necessary in evaluating the proposed project in
relation to flood heights and velocities, the serious-
ness of flood damage to the use, the adequacy of the
plans for protection, and other technical matters.
C. Based upon the technical evaluation of the designated
engineer or expert, the City Council shall determine
the Specific flood hazard at the site and evaluate the
suitability of the proposed use in relation to the
flood hazard.
S. Factors Upon Which the Decisions of the City Council Shall
be Based.
D.
The susceptibility of the proposed facility and its
contents to flood damage and the effect of such damage
on the individual owner.:
E.
The importance of'the,services pro -rid -ed by the proposed
facility to the community,
P.
The requirements of th'e - facility for a waterfront
location. ;
G.
The availability of alternative locations not subject
to flooding for the proposed use,
H,
The compatibility of the proposed use with existing ";
development and development anticipated in the fore:.
seeable future,
T.
Thi re],ationship. of the proposed use of the COMPREHENSIY
FL1tN ind'flood.plain manageaent.program for the area.
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,JThe safety ,of access to the property in times of flood..`
for ordinary and emergency vehicles,
K.
-he expected heights, velocity, duration, rate of ris.e
and sediment transport of the floodwaters expected
at the 'site-.
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such: ether: -factors which are relevant to the purposes
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of th# Ordinance.
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6. Dona tions A.toghed to Conditional Use Permits. Upon
consitea�atfon of t►e'factors listed above and the purposes I
f thaE�t�on, the City "Cour►cil may attach such conditions
as
to the granting of Conditional Use Permits as it deems
necessary to further the purposes of this Section. Among
such conditions without limitation because of specific
enumeration may be included:
A. Modification of waste disposal and water supply
facilities.
B. Limitations on period of use and operation.
C. Imposition of operational controls, surities, and deed
restrictions.
D. Requirements for construction of channel modifications,
dikes, levees and other protective measures.
E. Floud proofing measures, Flood proofing 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 City Council shall require that the
applicant submit a plan or document certified by a
registered professional engineer or architect that the
flood proofing measures are consistent with the
regulatory flood protection elevation and associated
flood factors for the particular area. The following
flood proofing measures may be required without
limitation because of specific enumeration:
1) Anchorage to resist flotation and lateral movement.
2) Installation of watertight doors, bulkheads, and
shutters, or similar methods of construction.
3) Reinforcement of walls to resist water pressures.
4) Use of paints, membranes, or mortars to reduce
seepage of water through walls.
5) Addition of mass or weight to structures to resist
flotation.
6) Installation of pumps to lower water levels in
structures. F
7) Construction of water supply and waF-e treatment
systems so as to prevent the entrant of flood water.
8) Installation of pumping facilities or comparable
pyac:ici.es for subsurface drainage systems for
'buildings to relieve external foundation wall
aged basement floor pressures,
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9) Construction to resist rupture or collapse caused
by water pressure or notating debris.
10) Installation of valves or controls on sanitary
and storm drains which will permit the drains to
be closed to prevent back-up of sewage and storm
waters into the buildings or structures. Gravity
draining of basements may be eliminated by
mechanical devices.
11) Location of any structural storage facilities
for chemicals, explosives, buoyant materials,
flammable liquids or other toxic materials which
could be hazardous to public health, safety, and
welfare above the flood protection elevation or
provisions of adequate floodproofing to prevent
flotation of storage containers, or damage to
storage containers which could result in the
escape of toxic materials into flood waters.
Subdivision 9. Nonconforming Uses.
1. If any Nonconforming Use is destroyed by any means,
including floods, to an extend of 50 percent or more
of its assessed value, it shall not be reconstructed
except in conformity with the provisions of this
Section. However, the City t1,ouncil may permit
reconstruction if the use is`.Iioc:,�ted outside the
floodway and, upon reconstrt{cfion, is adequately
floodproofed, elevated,,,,nr otherwise protected.,
?. Any alteration or addition to any Nonconforming Use
which would result in substantially increasing its
flood damage potential shall beprotectedby measures
pursuant to Subdivision 8 6A -E of this Section.
3. The Zoning Administrator shall prepare a list of those
Nonconforming Uses which have been floodproofed or
otherwise adequately protected in conformity with
Subdivision 8 6A -E. He shall present such list to the
City Council which may issue a certificate to the owner
stating that such uses as a result of these corrective
measures are in conformity with the provisions of this
Section.
Subdivision 10. Amendments.
The flood plain designation on zoning maps shall not be removed
from flood plain areas unless it can be shown that the desig-
nation is in error or that the areas are filled to an elevation
at or above the flood protection elevation and are contiguous
to other lands lying outside the flood plain district.
Special exceptions to this rule may be permitted by the
Commissioner of Natural Resources if he determines that,
through other measures, lands are protected adequately for
the intended uses.
All amendments to this Section including amendments to the
Flood Overlay Districts of the Official Zoning Map must be
submitted to and approved by the Commission of Natural
Resources prior to adoption, Changes to the Flood Overlay
Districts of the Official Zoning Map also require prior
approval by the Federal Insurance Administrator.
Section 2. Effective Date. This Ordinance shall take
effect upon its passage and publication.
Adopted by the City Council of. the City of Plymouth on
the 15th d:_y of May, 1978..
HOWARD L. HUNT, Mayor
ATTEST:
Loretta Garrity, Cit Clerk