HomeMy WebLinkAboutOrdinance 90.13 Amending the land development code to add floodplain and erosion hazard management0RDIIOIIICE N0. 90.13
AN ORDINANCE RESCINDING ORDINANCE NO. 87.02 ADOPTING A
FLOODPIJtlN AND EROSION HAZARD HANAGEI~.N~ CODE FOR ?NE
TONN OF HARANA AND ANENDING THE 'I'O~N DEVELOPMENT CODE
WHEREAS the Town of Marana did enact that certain
Ordinance No. 87.02 by action of the Town Council on March 3,
1987, and
WHEREAS substantial changes to the Floodplain and
Erosion Hazard Management Code have been recommended by Pima
County Flood Control District as pert of an Intergovernmental
Agreement for flood control on the lower Santa Cruz River; and
WHEREAS the Town Planning and Zoning Commission and the
Town Council of the Town of Marana, Arizona have determined that
adoption of the Floodplain end Erosion ~ozard Management Code for
the Town of Marana would be in the best interests of the Town and
its residents.
NOW, THEREFORE, BE IT ORDAINED by the Town Council of
the Town of Marana, Arizona that Ordinance No. 87.02 is hereby
rescinded.
BE IT FURTHER ORDAINED that that certain document
entitled "Floodplain and Erosion Hazard Management Code for the
Town of Marana", three copies of which are on file in the office
of the Town Clerk, is hereby declared to be a public record, and
said copies are ordered to remain on file with the Town Clerk.
BE IT FURTHER ORDAINED that the Floodplain and Erosion
Hazard Management Code, which public record is hereby adopted by
reference and incorporated herein as if fully set forth herein,
is hereby adopted and approved ss the Floodplain Management Code
for the Town of Marana.
BE IT FURTHER ORDAINED that the Town Development Code
shall be amended by adding the Floodplain and Erosion Hazard
Management Code to the Town Development Code as Title 2i thereof.
~HEREAS, the immediate operation of this Ordinance is
necessary for the preservation of the public peace, health and
safety of the Town of Marana, Arizona, an emergency is hereby
declared to exist, and this Ordinance shall be in full force and
effect from and after its passage and adoption.
~ASSED AND ADOPTF2) by the Mayor and Council of the Town
of Marana, Arizona this 17th day of Apr£1, 1990.
ATTEST:
APPROVED AS TO FORM:
Date Signed:
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TITLE 2!
FLOOD P~AIN AND EROSION HAZAP. D MANAGEMENT CODE
21.01
21.02
21.03
21.04
21.05
21.06
21.07
21.08
21.09
21.10
21.11
21.12
21.13
21.14
21.15
21.16
21.17
21.18
21.19
21.20
Short Title
Purpose, Interpretation, Application and Area of
Jurisdiction
Warning and Disclaimer of Liability
Definitions
Statutory Exemptions: Non-Conforming Uses
Floodplain Maps and Boundaries
Permits; Penalty
Floodway Requirements
Floodway Fringe Area Requirements
Standards for Manufactured Homes and Manufactured Home
Parks and Subdivisions
Subdivision and Development Requirements
Building Setback Requirements and Erosion Hazard Areas
Access Requirements
Detention/Retention Systems
Sediment and Erosion Control
Appeals
Variances
Amendments
Unlawful Acts, Penalty
Miscellaneous
Appendix 1, Table of Regulatory Peak Discharges
April 11, 1990
SECTION 21.01 SHORT TITLE: This Code may be referred to as the
Floodplain Management Code.
SECTION 21.02 STATEMENT OF PURPOSE: INTERPRETATION; APPLICATION
AND ARKA OF JURISDICTION
A. This Code shall apply within regulatory floodplain and erosion
hazard areas and for purposes of the detention/retention provisions
shall apply to development in the Marana Town limits.
B. This floodplain management code is one aspect of land and
resource management planning for the Town of Marana. Floodplain
management must be seen in perspective, not only as flood hazard
minimization; but as one element of an integrated and balanced
positive program of natural resource management and flood and
erosion hazard reduction.
The Council recognizes that it is both necessary and desirable to
maintain a balanced and cooperative relationship between human
communities and the land and resources which sustain them.
Maintaining the stability, health, diversity and natural ecosystems
of the environment is essential.
It is the intent of the Council that:
1. The highest and best use of floodplains in Town of Marana
is for maintenance of natural hydrologic and hydraulic processes,
groundwater recharge, aesthetics, natural open space, recreation
areas and wildlife habitat.
2. Any human habitation or structural developments which
limit natural processes within floodplain or erosion hazard areas
are to be discouraged end limited to the extent allowable by law.
3. The Town will acquire by appropriate means, and whenever
possible, lands within the regulatory floodway, floodway fringe and
erosion hazard areas. These lands are to be managed to preserve
or enhance natural values and expressed resource management goals.
4. Regulatory land use control for floodplain management will
focus on overall watershed management. Floodplain management will
be used to prevent unwise human occupation or encroachment into
flood and erosion hazard areas after the effective date of the
original Floodplain Management Ordinance, July 9, 1984. Structural
flood control measures may be used to prevent, reduce or eliminate
flood or erosion hazards to property and structures, both public
and private, constructed or occupied before the effective date of
the original Ordinance, except where flood hazards result from
increased urbanization.
5. Natural flood areas, streams, washes, arroyos, rivers, and
drainage courses are, whenever possible, to be preserved in their
natural riverine environment. Any land use proposal which proposes
this approach shall be considered superior to all others.
C. It is the purpose of this Code to protect the public health,
peace, safety, comfort, convenience and general welfare of the
citizens of the Town of Marana by adopting regulations designed:
1. To minimize flood and erosion damages and reduce the
height of floods;
2. To meet or exceed state and federal requirements relating
to floodplain management, thereby enabling Town residents to
purchase low cost flood insurance, receive disaster relief should
the need arise, and to seek residential and commercial real estate
loans;
3. To establish minimum flood protection elevations and flood
damage prevention requirements for structures and other types of
development which are vulnerable to flood and erosion damage;
4. To prevent unwise encroachment and building development
within areas subject to flooding or erosion, and assure that the
flood carrying capacity within the altered and/or relocated portion
of any watercourse is maintained;
5. To minimize expenditure of public money for costly flood
control projects;
6. To minimize the need for
associated with flooding and erosion
expense of the general public;
rescue and relief efforts
generally undertaken at the
7. To minimize damage to public facilities and utilities such
as water and gas mains, electric, telephone and sewer lines,
streets and bridges located in regulatory floodplain and erosion
hazard areas;
8. To help maintain a stable tax base by providing for the
development of areas of special flood and erosion hazard so as to
minimize future flood blight areas;
9. To assist potential buyers in receiving notice that
property may be in an area of special flood or erosion hazards;
10. To insure that those who occupy the areas of special
flood or erosion hazards assume the responsibility for their
actions;
11. To protect, preserve and enhance groundwater recharge.
12. To encourage the preservation of natural washes and
enhance the riverine environment.
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D. In the interpretation and application of this Code, all
provisions shall be:
1. Considered as minimum requirements;
2. Liberally construed in favor of the governing body; and
3. Deemed neither to limit or repeal any other powers granted
to the Town of Marana under any state statute or Town Ordinance.
Where this Code conflicts with or overlaps any other ordinance or
regulation, whichever imposes the more stringent restrictions for
the health, safety and welfare of the public shall prevail.
E. This Code shall be applicable and enforceable in all areas
within the corporate boundaries of the Town of Marana, including
public lands. The Town of Marana has chosen to exercise the
floodplain management powers and duties pursuant to Section 48-3610
of the Arizona Revised Statutes. From time to time the Town of
Marana, may choose to enter into separate agreements for the
administration of portions of its powers and duties under this
Code.
F. The performance requirements as specified in this Code are
minimum standards and address general floodplain management
requirements. Specific projects may warrant additional
requirements. The Floodplain Management Board and the Town
Floodplain Administrator have the authority to establish standards
and/or policies as necessary to carry out the provisions of this
Code. All drainage design standards, river and basin management
plans, or other land use plans approved by the Town Council or
Floodplain Management Board are hereby incorporated into this Code.
S~CTION 21.03 WA~NING A~D DISCLAIMER OF LIABILITY
A. The degree of flood protection required by this Code is
considered reasonable for regulatory purposes and is based on
engineering and scientific methods of study. Larger floods may
occur on occasion or the flood height may be increased by man-made
or natural causes, such as bridge openings restricted by debris.
This Code does not imply that areas outside floodways and floodway
fringe areas, or land uses permitted within such areas, will be
free from flooding or flood damage. This Code shall not create
liability on the part of the Town of Marana, the Town Floodplain
Management Board, or any officer or employee thereof for any flood
damages that may result from reliance on this Code or any
administrative decision based upon this Code.
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SECTION 21.04 DEFINITIONS
A. The following definitions shall apply to words and phrases used
in this Code:
.Balanced Basin/Watershed: A drainage basin or watershed which
contains floodwater channels, natural or man-made, and/or flood
control structures that are adequate to contain existing runoff
from the base flood produced by the basin or watershed; but in
which additional runoff cannot be safely contained by said channels
or structures.
Base Flood: The base flood (Ql00) shall mean the peak discharge of
a 100-year flood. The base flood has a one percent probability of
being equalled or exceeded in any given year. Said flood shall be
determined from an analysis of floods on a particular watercourse
and other watercourses in the same general region in accordance
with the criteria established by the Director of the Arizona
Department of Water Resources, or the Pima County Flood Control
District Board, which criteria is hereby incorporated by reference
and made s pert of this Code.
Rase Flood Elevation: The calculated water-surface elevation of
the base flood.
Critical Basin/#ater~hed: A drainage basin or watershed which
contains floodwater channels, natural or man-made, and/or flood
control structures that cannot contain existing runoff produced by
the base flood within the basin or watershed, and which has a
documented history of severe flooding hazards.
Critical Basin/Water~hed Nanaaement Plan: A site specific plan for
a balanced/critical basin or watershed which has been prepared for
and approved by the Town of Marana and provides a conceptual plan
for orderly development of flood control/floodplain management
measures within the basin or watershed.
Detention SYstem: A type of flood control system which delays the
downstream progress of flood waters in a controlled manner,
generally through the combined use of a temporary storage area and
a metered outlet device which causes a lengthening of the duration
of flow and thereby reduces downstream flood peaks.
Develo ment: Any man-made change to improved or unimproved real
estate, including but not limited to buildings or other structures,
mining, dredging, filling, grading, paving, fencing, excavating or
drilling.
Drains e Basin: The contributing area to a single point of
drainage concentration, expressed in units of area. Also called
catchment area, watershed, and river basin.
~ A deep hole, covered and designed in such a manner so
as to hold drainage water until it soaks into the ground.
Dwe11'n U it: A place of residence which may be located in a
single or multiple dwelling building or a manufactured home.
Encroachment, Eaual Dearee of: Encroachment is the advancement or
infringement of uses, fill, or structures into any regulatory
floodplain in a manner that impedes the flow capacity of the
channel and regulatory floodplain of a watercourse. An equal
degree of encroachment is a standard applied to the evaluation of
the effects of the encroachment on increases in flood heights. It
assumes that an encroachment, if permitted, may confer on all
property owners on both sides of the watercourse an equal right to
encroach to the same degree within that reach. Since the factors
affecting hydraulic efficiency are usually not uniform within a
reach, this standard will usually not result in equal measured
distances between floodway limit lines and the regulatory flood-
plain boundaries of the watercourse.
Erosion Hazard Area: Land adjoining a watercourse regulated by
this ordinance which is deemed by the Town or County Engineer to
be subject to flood-related erosion losses.
Flood: A temporary rise in water level, including groundwater or
overflow of water onto lands not normally covered by water.
FloodPlain N~na~ent: The operation of an integrated natural
resource management program, encompassing corrective and
preventive measures for reducing flood and erosion damage,
including but not limited to emergency preparedness planning, flood
control works and floodplain management regulations.
Floodplain N~a~ent Board: The Town Council for the Town of
Marana, Arizona.
Floodplain N~ao~nt Re~ulations: The codes, ordinances and other
regulations relating to the use of land and construction within the
regulatory floodplain, including zoning ordinances, subdivision
regulations, building codes, housing codes, setback requirements,
open-area regulations and similar methods of control affecting the
use and development of these areas.
Flood~la~, Use Permit: An official document which authorizes
specific activity within the regulatory floodplain.
Flood Proofin : A combination of structural provisions, changes,
or adjustments to properties and structures subject to flooding
which are primarily used for the reduction or elimination of flood
damages to properties, water and sanitary facilities, structures,
and contents of buildings in a flood hazard area.
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~ The channel of a river or other watercourse and the
adjacent land area necessary in order to discharge the one-hundred
year flood without cumulatively increasing the water surface more
than one (1) foot and without creating hazardous velocities of
flood waters. In determining the floodway limits it shall be
assumed that the area landward (outside) of the floodway lines will
be ultimately developed in such a way that it will not be available
to convey flood flows (See Exhibit 1).
Floodway Fr~n~e Ares: Land outside the floodway and below the
regulatory flood elevation.
Geologic FloodD1A~,: That portion of the land that has, in the
geologic past, been subject to fluvial processes. The geologic
floodplain may be different than the regulatory floodplain.
Levee: A man-made structure, usually an earthen embankment
designed and constructed in accordance with sound engineering
practices to contain control, or divert the flow of water so as to
provide protection from temporary flooding.
Lowest Flo r: The floor of the lowest enclosed area of any
development.
Manufactured Home: A structure transportable in one or more
sections which is built on a permanent chassis and designed to be
used with or without a permanent foundation when connected to the
required utilities. For floodplain management purposes, the term
manufactured home also includes park trailers, travel trailers and
other similar vehicles placed on a site for greater than 180
consecutive days.
Manufactured ~e Park or Subdivision A subdivision designed and
intended for sale of lots for residential occupancy in manufactured
housing.
Mean Sea Lev 1: For purposes of the National Flood Insurance
Program, the National Geodetic Vertical Datum (NGVD) of 1929 or
other datum, to which base flood elevations shown on a community's
Flood Insurance Rate Map are referenced.
~ Any physical alteration in, along, across, or
projecting into any channel, watercourse, stream, lake, or
regulatory floodplain area which may impede, retard or change the
direction of the flow of water, either in itself or by catching or
collecting debris carried by such water, or that is placed where
a flow of water might carry the same downstream to the damage of
life or property. Examples include, but are not limited to, the
following: any dam, wall, wharf, embankment, levee, dike, pile,
r '
abutment, P o3ect=on, excavation, channel rectification, bridge,
conduit, culvert, building, wire, fence, rock, gravel, refuse,
fill, structure or vegetation.
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~ Any individual or his agent, firm, partnership, associa-
tion, corporation, or agent of the aforementioned groups, or the
State or any agency or political subdivision thereof.
Reach: A hydraulic engineering term used to describe longitudinal
segments of a stream or watercourse. In an urban area an example
of a reach would be the segment of a watercourse between two con-
secutive bridge crossings.
Reclamation Plan: A plan for sand and gravel operations which
defines hydrologic and hydraulic constraints; outlines methods of
extraction, operation and site development, and provides for back-
filling procedures and final site reclamation.
Regulatory Flood Elevation: The elevation which is one foot above
the calculated water-surfaCe elevation of the base flood.
Regulatory Floodplain: That portion of the geologic floodplain
associated with a watercourse or that area where drainage is or may
be restricted by man-made structures and that would be inundated
by the base flood where the peak discharge of the flow is one-
hundred cubic feet per second (cfs) or greater, or those areas
which are subject to sheet flooding, or those areas mapped as being
floodprone on existing recorded subdivision plats (See Exhibit 1).
Retention System: A type of flood control system which stops the
downstream progress of flood waters by employing methods of total
containment which generally involve creation of storage areas which
incorporate infiltration devices such as dry wells to dispose of
stored waters, principally by percolation over some specified
period of time, thereby eliminating basin contributions to
downstream flood peaks or flood volumes. Alternately, flood waters
can be stored and used as a direct substitute for irrigation by
groundwater provided that the water is used at a specified minimum
rate and that minimum storage capacities are maintained at all
times.
Setback: The minimum horizontal distance between a structure and
a watercourse. On each side of a watercourse, the setback is
measured from the top edge of the highest channel bank or edge of
the base flood water-surface elevation, whichever is closer to the
channel centerline.
Sh et F o in : Those areas which are subject to flooding with
depths of one-half (1/2) foot or greater during the regulatory
flood where a clearly defined channel does not exist and the path
of the flooding is often unpredictable and indeterminate.
~ Anything constructed or erected, the use of which
requires location on the ground or attachment to some foundation
having a location on the ground.
Town Floodplain
Administrator and any other Town
Planning and Zoning Administrator.
The Town Planning and Zoning
staff designated to assist the
~ A grant of relief from the requirements of this Code
which permits construction in a manner that would otherwise be
prohibited by this Code.
~ The failure of a structure or other development to be
fully compliant with this Code.
~ Any lake, river, s~ream, creek, wash, arroyo, or
other boay of water or channel having banks and bed through which
w~ters flow at least periodLcally and any depression serving to
give direction to a current of storm water, provided that, it
shall, upon rule or order of the Floodplain Management Board, also
include other designated areas where substantial flood damage may
OCCUr.
The drainage area above a point on a watercourse.
SECTION 21.05 STATUTORY EXeMPtIONS: NON-CONFORMING USES
A. As specified in Arizona Revised Statutes (A.R.S.) 48-3609 the
provisions of this Code shall not affect or prohibit:
1. Existing legal uses of property or the right to contin-
uation of such legal uses. However, if a non-conforming use of
land, building or structure is discontinued for twelve (12) con-
secutive months or destroyed to the extent of fifty (50) percent
of its value, as determined by a competent appraiser, any further
use shall comply with this Code.
2. Reasonable repair or alteration of property for the pur-
poses for which the property was legally used on July 9, 1974,
except that any alteration, addition or repair to a non-conforming
building or structure which would result in increasing its flood
damage potential by fifty (50) percent or more shall be either
flood proofed or elevated to at or above the base flood elevation.
3. Reasonable repair of structures constructed with
written authorization required by Arizona Revised Statute:
48-3613.
the
4. Facilities constructed or installed pursuant to a certifi-
cate of environmental compatibility issued pursuant to Title 40,
Chapter 2, Article 6.2 of Arizona Revised Statutes.
B. As specified in A.R.S. 48-3613 before construction of the
following may begin, plans for the construction must be submitted
to the Floodplain Management Board for review and comment; however,
the following shall not be prohibited and shall not require a
Floodplain Use Permit or other written authorization:
1. The construction of bridges, culverts, dikes and other
structures necessary for the construction of public highways,
roads, and Streets intersecting or crossing a watercourse.
2. The construction of storage dams for watering livestock
or wildlife and the construction of structures on banks of a water-
course to prevent erosion of or damage to adjoining land if the
structure will not divert, retard or obstruct the natural channel
of the watercourse; or dams for the conservation of floodwaters.
3. Construction of tailing dams and waste disposal areas used
in connection with mining and metallurgical operations. This para-
graph does not exempt those sand and gravel operations which will
divert, retard or obstruct the flow of waters in a watercourse from
complying with and acquiring authorization from the Council
pursuant to the regulations adopted by the Council under this Code.
4. Other construction if it is determined by the Floodplain
Management Board that written authorization is unnecessary.
5. Any flood control district, county, city, town or other
political subdivision from exercising powers granted to it under
Arizona law.
6. The construction of streams, waterways, lakes and other
auxiliary facilities in conjunction with development of public
parks and recreation facilities by a public agency or political
subdivision.
7. The construction and erection of poles, towers, founda-
tions, support structure, guy wires, and other facilities related
to power transmission as constructed by any utility whether a
public service corporation or a political subdivision.
C. This article shall not exempt any person from obtaining a
floodplain use permit as set forth in this Code for any use which
diverts, retards or obstructs the flow of water and creates a
danger or hazard to life or property in the area.
D. These exemptions do not preclude any person from liability if
that person's actions increase flood hazards to any other person
or property.
E. Non-Conforming Uses
1. Improvements to or reconstruction of existing
conforming uses.
a. Any structure which is repaired, reconstructed,
or substantially improved at a cost equal to or exceeding
fifty (50) percent of the value of the structure as shown
on the latest assessment rolls of the Pima County
Assessor either (a) before the improvement or repair is
started~ or (b) if the structure has been damaged and is
being restored, before the damage occurred, shall conform
non-
to the provisions of this Code. For the purpose of
determining the value of any such construction, repair
or alteration, the normal retail value of the materials
and the reasonable value of the labor performed shall be
used. No person shall repair or alter property in a
piecemeal manner so es to avoid the provision of this
section.
b. For the purpose of this article substantial
improvement is considered to occur when the first
alteration of any wall, ceiling, floor, or other
structural part of the building commences, whether or not
that alteration affects the external dimension of the
structure. The term does not, however, include any
project for improvement of a structure to comply with
existing State or local health, sanitary or safety code
specifications which are solely necessary to assure safe
living conditions.
2. Discontinuance of Non-Conforming Use. In the event that
the use of a non-conforming use is discontinued for a period of
twelve (12} consecutive months, any further use thereof shall be
in conformity with the provision of this Code.
SECTION 21.06 FLOODPLAIN MAPS AND BOUNDAKIES
A. The boundaries of the regulatory floodplains and the floodways
for which adequate hydrologic and hydraulic data is available for
their delineation on maps shall be shown on maps maintained by the
Town Floodplain Administrator.
1. The Federal Emergency Management Agency (FEMA) has
identified certain flood hazard areas in an engineering report
entitled "The Flood Insurance Study for the Town of Marana,
Arizona", hereinafter referred to as The Flood Insurance Study,
dated September 4, 1987, with accompanying Flood Insurance Rate
Maps and Flood Boundary end Floodway Maps, as well as Flood
Insurance Studies, Flood Insurance Rate Maps and Flood Hazard
Boundary Maps for all the areas within Pima County, all of which
are hereby incorporated by reference and declared to be a part of
this Code. The delineation of the 100-year floodplains and the
floodways shown on these maps shall be the regulatory floodplains
and floodways governed by this Code for those watercourses studied
with the exception of the Santa Cruz River. The Flood Insurance
Study and the accompanying maps are on file in the offices of the
Floodplain Administrator of the Town of Marana. Amendments by the
Federal Emergency Management Agency to the Flood Insurance Study
and its accompanying maps shall be incorporated in the floodplain
maps maintained by the Town Floodplain Administrator.
2. Due to continuously and episodically changing hydrologic
and hydraulic conditions on the watercourses within Pima County,
base flood peak discharges, flow volumes, and associated regulatory
floodplain and erosion hazard areas are continuously subject to
revision. At a minimum, base flood values will meet or exceed the
current values established by the FEMA, and reflect historic flood
information and general, current, watershed conditions. Current
regulatory floodplain and erosion hazard area maps will be
maintained by the Town Floodplain Administrator for the Santa Cruz
River.
a. All watersheds which generate regulatory flood
peak discharges exceeding 5,000 cfs for the 100-year
flood discharge shall have their flood peak discharges
listed by the Town Floodplain Administrator and adopted
by the Town Council. (See Appendix I) These discharges
will be amended, if necessary, as revised flood peak
predictions become available.
3. In those areas where the regulatory floodplain and erosion
hazard areas are not delineated pursuant to paragraphs i and 2 of
this section, and upon request for a town permit the Town
Floodplain Administrator may require the land owner to establish
the regulatory floodplain and floodway limits through a hydrologic
and hydraulic study prepared by an Arizona Registered Professional
Civil Engineer.
4. In those areas where a hydrologic and hydraulic study has
been prepared by an Arizona Registered Professional Civil Engineer
which delineates the regulatory floodplains, floodways, and erosion
hazard areas and has been approved by the Town Engineer, the
delineation of those boundaries shown within the study shall be the
regulatory floodplain, floodway, and erosion hazard areas governed
by this Code.
5. Prior to the release of assurances for subdivisions or
certificate of occupancy for development plans, construction of any
improvement which changes the configuration of the delineated
floodplain contained in the Flood Insurance Study, whether upstream
of, downstream from or adjacent to the development, the person
responsible for the installation of the improvement shall provide
to the Town of Marana a new delineation of all floodplains affected
by the improvement. The new delineations and reports shall be
prepared in conformance with the requirements of FEMA, the Director
of Water Resources and this Code. The Town of Marana will submit
the required flood insurance study information to Federal Emergency
Management Agency within 15 days of receipt.
6. Engineering studies showing the regulatory floodplain and
erosion hazard areas may be prepared under the direction of the
Town Engineer. Upon approval by the Town Engineer, these maps
shall be the regulatory floodplain and erosion hazard areas
governed by this Code.
7. Where a question arises as to the exact location of any
regulatory floodplain, floodway, or erosion hazard area, the
question shall be decided by the Town Floodplain Administrator and
his decision shall he final except as provided for in Section
21.16. If there appears to be a conflict between a mapped boundary
and actual field conditions, the Town Floodplain Administrator may,
if so desired, use the water surface elevation of the base flood
for the area in question as the governing factor in locating the
boundary in question. Any person contesting the location of any
boundary shall be given a reasonable opportunity to present his own
technical evidence if he so desires.
8. Where presently platted or mapped regulatory floodplain
and erosion hazard areas are different than previously approved
regulatory floodplain and erosion hazard areas, the most recent
information shall apply.
SECTION 21.07 PERMITS; PEN~J~TY
A. Floodnlain Use Permit Reauired
1. From and after the effective date of this Code it shall
be unlawful to cause or allow any development to occur on any land
within the regulatory floodplain or within erosion hazard areas
without first applying for and obtaining a floodplain use permit
from the Town Floodplain Administrator, and thereafter complying
with each and every written term of the permit. However, no such
floodplain use permit shall be required for any repairs or
alterations for which the value of the materials and labor thereon
does not exceed $1,500.00 except for those improvements which
obstruct the flow of floodwater. For the purpose of determining
the value of any such repairs or alterations, the normal retail
value of materials and the reasonable value of the labor performed
shall be used. Even though no floodplain use permit is required,
all other provisions of this Code shall be observed in the
performance of said repairs or alterations. Repairs or alterations
shall not be done in a piecemeal fashion for the purpose of
avoiding applying for a permit when the total cost of said work is
in excess of $1,500.00.
2. Every new structure, building, fill, excavation or
development located or maintained within any regulatory floodplain
or erosion hazard area in violation of this Code and without
written authorization from the Floodplain Management Board is a
public nuisance per se and may be abated, prevented or restrained
by action of the Town.
3. In addition to other penalties or remedies otherwise
provided by law, the Town or any person who may be damaged as a
result of the diversion, retardation or obstruction of water within
the regulatory floodplain, shall have the right to commence,
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maintain and prosecute any appropriate action or pursue any remedy
to enjoin, abate or otherwise prevent any person from violating or
continuing to violate any provision of this Code. If any person
is found to be in violation of any provision of this Code, the
court shall require the violator to comply with this Code or remove
the obstruction and restore the regulatory floodplain to its
original condition.
4. As a further remedy, the Town of Marana may withhold the
issuance of building permits or floodplain use permits for any
development or improvement on the same parcel, or on a contiguous
parcel of land under the same ownership, where any improvement or
development on the property is not in compliance with this or any
other provision of law relating to that development.
B. Issuance of Permit~
1. It shall be the duty of the Town Floodplain Administrator
to issue the floodplain use permits required by this Code. The Town
Floodplain Administrator may request and shall receive, so far as
may be necessary in the discharge of his duties, the assistance
and cooperation of all departments, agencies, officials and public
employees of the Town of Merana in the enforcement of this Code.
No license, permit or other similar approval for any development
which would be in conflict with the provisions of this Code shall
be issued by any department, official or employee of the Town of
Marana~ and any such license, permit or approval, if issued in
conflict with the provisions of this Code shall be null and void.
2. The Town shall advise Pima County, which has assumed
jurisdiction over its floodplains in accordance with Arizona
Revised Statute No. 48-3610, in writing and provide a copy of any
development plan of any application for a floodplain use permit or
variance to develop land in a regulatory floodplain, floodway or
erosion hazard area within one mile of the Town's exterior
boundaries. The Town shall also advise Pima County in writing and
provide a cody of any development plan of any major development
proposed within a regulatory floodplain, floodway, or erosion
hazard area which could affect floodplains, floodways or
watercourses within the County's area of jurisdiction. Written
notice and a copy of the plan of development shall be sent to any
adjacent jurisdiction no later than three working days after having
been received by the Town.
C. Permit Procedures
Upon receiving an application for a floodplain use permit, the Town
Floodplain Administrator may require the applicant to:
1. Submit, where applicable, plans in triplicate drawn to
scale showing the nature, location, dimensions and elevation of the
lot, existing or proposed structure, fill, storage of materials,
13
flood proofing measures and the relationship of the above to the
location of the channel, floodway, regulatory floodplain and
erosion hazard area boundaries and the base flood elevation. All
elevations or vertical distances must reference an established
datum or base elevation. If the proposed development in the
floodplain is located within one mile of the Town boundaries or,
within the Santa Cruz River floodway or within 500 feet of the
Santa Cruz River Channel Banks, an additional copy of the
development plan and or subdivision plat and or plans including all
reports and attachments shall be submitted for forwarding to the
Pima County Flood Control District.
2. Where special circumstances necessitate more detailed
information, the applicant must furnish any or all of the following
as is deemed necessary by the Town Floodplain Administrator for the
evaluation of the effects of the proposed use upon flood flows and
other factors necessary to render a decision on the suitability of
the proposed use.
a. Valley cross-sections showing the existing
channel of the stream, elevation of land areas adjoining
each side of the channel, cross-sectional areas to be
occupied by the proposed development and high water
information. '
b. Plan (surface view) showing elevations or
contours of the ground~ pertinent structures, fill, or
storage elevations; size, location and spatial
arrangement of all proposed and existing structures and
channel banks on the site~ location and elevation of
streets, water supply, sanitary facilities; photographs
showing existing land uses and vegetation upstream and
downstream, soil types, and other pertinent information.
c. Profile showing the elevation and slope of the
bottom of the channel or flow line of the stream or
watercourse.
d. Specifications for building construction and
materials, flood proofing, filling, dredging, grading,
channel improvements, storage of materials, water supply,
and sanitary facilities.
e. Engineering study prepared by an Arizona
Registered Professional Civil Engineer outlining the
effects the development will have on the flow of water
through the area being developed and the surrounding
areas. This study will be for the purpose of evaluating
possible flood hazards and shall, where necessary,
include consideration of the effects of the development
on flood heights, water velocities, direction of flow,
sedimentation and/or erosion, volume of flows, channel
shape and size, type of channel banks and other items
that may be pertinent, and the resultant effects on
structures, land, banks, etc. for the respective
floodplain and the surrounding area.
3. The Town Floodplain Administrator shall review the
proposed development to assure that all necessary permits have been
received from those governmental agencies from which approval is
required by Federal or State law including Section 404 of the
Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C.
1134.
D. Denial of Permit
No permit shall be issued for any development which is not in
conformance with this Code or any other provision of law relating
to such development. A floodplain use permit may be denied if the
proposed development constitutes a danger or hazard to life or
property. In making such a determination the Town Floodplain
Administrator may consider the following factors, which list is not
intended to be all-inclusive:
1. The danger to life, person, or property due to increased
flood heights, velocities, or redirection of flow caused by the
development.
2. The danger that materials may be swept on to other lands
or downstream to the injury of others.
3. The proposed water supply and sanitation systems of any
development and the ability of these systems to prevent disease,
contamination and unsanitary conditions if they should become
flooded.
4. The susceptibility of the proposed development and/or its
contents to flood damage and the effect of such damage on the
individual owners.
5. The availability of alternative locations for the proposed
use on the same property which are not subject to flooding or
erosion.
6. The compatibility of the proposed use with existing
floodplain uses and with floodplain management programs anticipated
in the foreseeable future.
7. The relationship of the proposed use to any comprehensive
plan and floodplain management program for the area.
8. The all weather access to the property in times of flood
for ordinary and emergency vehicles.
9. The expected heights, velocity, duration, rate of rise and
sediment transport of the flood waters expected at the site under
both existing and proposed conditions.
10. Documentation that all necessary permits have been
obtained from State and Federal agencies.
11. Such other factors which are relevant to the purposes of
this Code.
Any floodplain use permit may be subject to conditions or restric-
tions designed to reduce or mitigate the potential danger or hazard
to life or property resulting from development within the
regulatory floodplain, floodway or erosion hazard areas. The
applicant may be required to execute deed restrictions running with
the land or be required to post performance bonds, assurances or
such other security as may be appropriate and necessary to assure
the performance of the conditions or restrictions that may be
imposed. Examples of conditions that may be imposed include, but
are not limited to, the following:
1. Modification of waste disposal and water supply
facilities.
2. himitations on periods of use and hours of operation.
3. Institution of operation controls, sureties related
temporary uses, and deed restrictions.
to
4. Requirements for construction of channel modifications,
dikes, levees and other protective measures.
5. Indemnification agreements whereby the applicant agrees
to hold the Town of Marana, and the Floodplain Management Board and
their officers, employees and agents, harmless and defend them from
any and all claims for damages now and in the future relating to
the use of the property sought to be developed by reason of
flooding, flowage, erosion or damage caused by water whether
surface, flood or rainfall.
6. Flood proofing measures for non-residential structures,
such as the following, which shall be designed to be consistent
with the base flood elevation for the particular area, flood
velocities, durations, rate of rise, h~drostatic and hydrodynamic
forces, and other factors associated with the regulatory flood.
The Floodplain Management Board may require that the applicant
submit a plan or document certified by an Arizona Registered
Professional Civil Engineer that the flood proofing measures are
consistent with the base flood elevation and associated flood
factors for the particular area. Examples of flood proofing
measures may be required include, but are not limited to:
a. Anchorage to resist flotation and lateral
movement.
b. Installation of watertight doors, bulkheads, and
shutters.
c. Reinforcement of walls to resist water
pressures.
d. Use of paints, membrane, or mortars to reduce
seepage of water through walls.
e. Addition of mass or weight to structures to
resist flotation.
f. Installation of pumps to lower water levels in
structures.
g. Construction of water supply and waste treatment
systems so as to prevent the entrance of flood waters.
h. Pumping facilities for subsurface external
foundation wall and basement floor pressures.
i. Construction designed to resist rupture or
collapse caused by water pressure or floating debris.
j. Cut-off valves on sewer lines or the elimination
of gravity flow basement drains.
Elevation of structures or uses.
Bank protection or armor plating on any proposed
Any person who fails to obtain the permit required by this article
or who fails to comply with the terms and conditions of said permit
shall be guilty of a Class i misdemeanor. Any person who commences
development prior to obtaining a required permit shall also pay
double the permit fee.
G. Revocation of Permit
For failure to comply with the terms of the floodplain use permit,
the Town shall be entitled to revoke the floodplain use permit upon
written notice by registered mail or personal delivery to the
applicant citing the reasons for revocation. The person holding
the floodplain use permit may request a hearing before the Town
Floodplain Administrator within ten (10) working days from the
receipt of notice or personal delivery where the merits of and
reasons for revoking the permit are heard. After considering the
issues and facts presented during the hearing, the Town Floodplain
17
Administrator may revoke a previously issued floodplain use permit.
If no request for a hearing is made within ten (10) work days from
the receipt of notice, the permit shall be considered revoked. The
applicant or any affected party may appeal the decision of the Town
Floodplain Administrator by requesting a hearing before the
Floodplain Management Board in accordance with Section 21.16.
H. Removal of Violation
Upon written notice, the Town Floodplain Administrator may cause
any structure, encroachment or work constructed without a flood-
plain use permit, or which is in violation with the terms of a
permit, to be removed immediately at the expense of the person who
caused the structure, encroachment or work if said structure,
encroachment or work will cause an immediate danger to life and
property.
I. Recovery of Costs
The Town of Marana shall be entitled to recover all costs,
including but not limited to administrative, engineering and legal,
as well as actual costs to remove or modify the structure,
encroachment and any other work in violation of this Code.
J. Certif'cation
Prior to either the pouring of the first slab or the finished floor
inspection, the applicant shall submit certification of elevations
required in the floodplain use permit or by this Code. Such
certification shall be prepared by an Arizona Registered Land
Surveyor or Professional Engineer, as appropriate, and provided to
the Town Floodplain Administrator. Such certification shall be
maintained by the Town Floodplain Administrator.
SECTION 21.08 FLOODWAY REQUIREMENTS
A. Uses Allowed
Except as provided for in this article, no other use shall be
allowed in any floodway. The following open space uses shall be
permitted within the floodway to the extent that they are not
prohibited by any provision of this Code or any other ordinance,
law or regulation, and provided they do not require fill,
excavation, or the storage of materials or equipment:
grazing,
farming,
Agricultural uses, including general farming, pasture,
outdoor plant nurseries, horticulture, viticulture, truck
sod farming, and wild crop harvesting.
2. Industrial-commercial uses such as loading areas, airport
landing strips, parking areas.
3. Private and public recreational uses, including 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.
4. Accessory residential uses, including lawns, gardens,
parking areas and play areas.
B. Excavations; Includino Sand and Gravel Oneration..
1. Extraction of sand, gravel, and other materials is allowed
within the floodways and flood hazard areas provided that
excavations are not so located nor of such depth, or width, or
length, or combination of depth-width-length as to present a hazard
to structures (including but not limited to roads, bridges,
culverts, and utilities), to the banks of watercourses, to other
property, or which adversely affect groundwater recharge.
2. There shall be no stockpiling within the floodways and
flood hazard areas of material or tailings that may obstruct,
divert, or retard the flow of floodwaters except as reviewed and
approved by the Town Floodplain Administrator on an individual
Floodplain Use Permit basis.
3. Excavations may be allowed only in those reaches of
watercourses which have, at a minimum, a balanced sediment system,
i.e. the sediment coming into the reach is equal to or greater than
the sediment leaving the reach and the long term sediment balance
for the entire river system indicates that the stream channel will
aggrade.
4. Due to the rapidly changing hydraulic characteristics of
watercourses in the Town of Marana, and the effects excavations
have on these characteristics, Floodplain Use Permits for excava-
tions shall only be issued for a limited time period, not to exceed
one (1) year, subject to annual renewal upon review by the Town
Floodplain Administrator.
5. In addition to those conditions provided for elsewhere,
floodplain use permits for excavations may impose conditions
regarding the area and location in which excavations are allowed,
the maximum amount of material to be excavated, and other
reasonable restraints on the methods of operating, including time
restraints.
6. Any extraction of sand and gravel or related materials in
a floodway or flood hazard area will only be allowed after the
effective date of this Code if a reclamation plan is also provided
for the extraction operation. The reclamation plan shall show in
19
sufficient detail the actions which are proposed to reclaim the
excavated areas so that all adverse effects of extraction are
mitigated. The plan shall also contain a timetable and financial
assurances for accomplishing reclamation.
7. The Town Floodplain Administrator
other financial assurances appropriate for
extraction operation.
may require bonds or
the sand and gravel
8. The Town Floodplain Administrator may require hydrologic,
hydraulic and geomorphic analyses addressing the existing
conditions as well as the impacts under the proposed method of
operation.
9. The Floodplain Management Board may grant variances as
provided by Section 21.17 of this Code.
C. Limitations
No use shall be allowed which:
1. Acting alone or in combination with existing or future
uses creates danger or hazard to life or property. In determin-
ing whether a use creates a danger or hazard to life or property,
the Town Floodplain Administrator may require a certification by
Registered Professional Civil Engineer that the proposed use will
not result in any increase in the floodway elevations during the
occurrence of the base flood, nor will the proposed use divert,
retard or obstruct the flow of flood waters.
2. Increases the regulatory floodway elevation.
3. Adversely affects groundwater recharge.
4. Increases erosion potential upstream and/or downstream.
5. Places a waste disposal system wholly or partially in a
floodway.
D. Flood Control Structure~
Flood control structures designed to protect life or property from
the dangers or hazards of floodwaters are permitted provided all
other provisions of this Code are met.
SECTION 21.09 FLOODWAY FRINGE AR~A REQUIKEMENTS
A. Uses Allowed
Any use to the extent not prohibited by this Code or any
ordinance or law is allowed within the floodway fringe area.
other
B. General ConditioDQ
The following general conditions shall apply to all uses within the
floodway fringe area. No development, storage of materials or
equipment, or other uses shall be permitted which acting alone or
in combination with existing or future uses, create a danger or
hazard to life or property. Consideration of the effects of a
proposed use or development shall be based on a reasonable assump-
tion that there will be an equal degree of encroachment extending
for a significant reach on both sides of the watercourse.
1. Fill
a. Any fill proposed to be deposited in the
floodway fringe must be shown to have some beneficial
purpose and the amount thereof not greater than is
necessary to achieve that purpose, as demonstrated by a
plan submitted by the owner showing the uses to which the
filled land will be put and the final dimensions of the
proposed fill or other materials.
against
heading,
Such fill or other materials shall be protected
erosion by riprap, vegetative cover, bulk-
or other approved methods.
c. Such fill shall not adversely affect the
groundwater recharge conditions in the subject area.
2. Structures
a. Structures shall be constructed so as to offer
the minimum obstruction to the flow of flood waters.
Whenever possible, structures shall be constructed with
the same alignment as the direction of flood flow and so
far as practicable shall be placed approximately on the
same alignment as those of adjoining structures.
b. All structures shall be firmly anchored to
prevent their flotation, which might otherwise result in
damage to other structures or restriction of bridge
openings and other narrow sections of the watercourse.
c. Service facilities such as electrical and
heating equipment shall be constructed at or above the
regulatory flood elevation for the particular area or be
adequately flood proofed.
d. Any structure designed or utilized for human
habitation, whether full or part time, shall have the
lowest floor elevated at or above the regulatory flood
elevation. Prior to the pouring of the first slab or
finish floor inspection the applicant shall submit to the
Town Floodplain Administrator certification by an Arizona
Registered Land Surveyor that the elevation of the lowest
floor is in compliance with the Floodplain Use Permit.
e. Enclosed areas within the regulatory floodplain
and below the regulatory flood elevation shall be
designed to equalize hydrostatic flood forces on exterior
walls by allowing for the entry and exit of floodwaters.
f. If fill is used to elevate any structure, the
minimum elevation of the fill shall be at or above the
base flood elevation and shall extend at such elevation
for a distance of at least twenty-five feet beyond the
outside limit of the structure unless a study/analysis
prepared by an Arizona Registered Professional Civil
Engineer demonstrates that a lesser distance is
acceptable.
g. Structures designed or utilized for human
habitation, whether full or part time, shall only be
permitted where the product of the flow depth d, in feet,
times the square of the flow velocity v, in feet per
second, of the surrounding floodwaters of the base flood
does not exceed the numerical value of eighteen
(dy2 ! 18} for a period in excess of thirty minutes, and
the surrounding floodwaters of the base flood do not
exceed three feet in depth.
3. Storage of Materials and Equipment
a. The storage and/or processing of materials that
are buoyant, flammable, explosive or that could be
injurious to human, animal or plant life in time of
flooding is prohibited.
b. Storage of other material or equipment may be
allowed if it is not subject to ma]or damage by floods
and is firmly anchored to prevent flotation or is readily
removable from the area within the limited time available
after flood warning.
4. Utilities
a. All new end replacement water supply, treatment,
and sewage collection and disposal systems built in a
regulatory floodplain shall be designed to eliminate to
the degree physically possible, in accordance with
Arizona Department of Environmental Quality guidelines,
infiltration of floodwaters into these systems and
discharge from these systems into flood waters.
b. On-site sanitary waste disposal systems shall
be located to avoid impairment to them or contamination
from them during flooding.
5. Excavations~ Including Sand and Gravel Operations
a. Extraction of sand, gravel, end other materials
is allowed within the flood way fringe provided that
excavations are not so located nor of such depth, or
width, or length, or combination of depth-width-length
as to present a hazard to structures (including hut not
limited to roads, bridges, culverts, and utilities), to
banks or watercourses, to other property, or which
adversely affect groundwater recharge.
b. There shall be no stockpiling of material or
tailings that may obstruct, divert, or retard the flow
of floodwaters except as reviewed and approved by the
Town Floodplain Administrator on an individual Floodplain
Use Permit basis.
c. Due to the rapidly changing hydraulic
characteristics of watercourses in the Town of Marana,
and the effects excavations have on these
characteristics, floodplain use permits for excavations
shall only be issued for a limited time period, not to
exceed one (1) year, subject to annual renewal upon
review by the Town Floodplain Administrator.
d. In addition to those conditions provided for
elsewhere, floodplain use permits for excavations may
impose conditions regarding the area and location in
which excavations are allowed, the maximum amount of
material to be excavated, and other reasonable restraints
on the methods of operation, including time restraints.
e. Any extraction of sand and gravel or related
materials in the floodway fringe or flood hazard areas
will only be allowed after the effective date of this
Code if a reclamation plan is also provided for the
extraction operation. The reclamation plan shall show
in sufficient detail the actions which are proposed to
reclaim the excavated areas so that all adverse effects
of extraction are mitigated. The plan shall also contain
a timetable and financial assurances for accomplishing
reclamation.
f. The Town Floodplain Administrator may require
bonds or other financial assurances appropriate for the
sand and gravel extraction operation.
g. The Town Floodplain Administrator may require
hydrologic, hydraulic and geomorphic analyses addressing
the existing conditions, as well as, the impacts under
the proposed method of operation.
SECTXON 21.10 STANDARDS FOR MANUFACTUI~D HOMES AND MANUFACTURIED
HOME PARKS AND SUBD/VZS/ONS
A. Permi Re uired
From the effective date of this Code it shall be unlawful to place
a manufactured home within a regulatory floodplain, as described
in Sections 21.07 and 21.08 of this Code, or erosion hazard areas
as described in Section 21.12 of this Code, for more than 180
consecutive days without first applying for and obtaining a
Floodplain Use Permit from the Town Floodplain Administrator, and
thereafter complying with each and every written term of the
permit. However, no such Floodplain Use Permit shall be required
for any repairs or alterations for which the value of the materials
and labor thereon does not exceed $1500.00 except for those
improvements which obstruct the flow of floodwaters. For the
purpose of determining the value of any such repairs or
alterations, the normal retail value of materials and the
reasonable value of labor performed shall be used. Although no
Floodpl&in Use Permit is required, all other provisions of this
Code shall be observed in the performance of said repairs or
alterations. Repairs or alterations shall not be done in a
piecemeal fashion for the purpose of avoiding applying for a permit
when the total cost of said work is in excess of $1§00.00.
B. General Provision~
All manufactured homes and additions to manufactured homes located
within the regulatory floodplain or erosion hazard area shall be
anchored to resist flotation, collapse, or lateral movement by one
of the following methods:
1. By providing an anchoring system designed to withstand
horizontal forces of 25 pounds per square foot and uplift forces
of 15 pounds per square foot~ or
2. By providing over-the-top and frame ties to ground
anchors. Specifically:
a. Over-the-top ties be provided at each of the
four corners of the manufactured home, with two
additional ties per side at intermediate locations,
except that manufactured homes less than fifty (50) feet
long require only one (1) additional tie per side~ and
b. Frame ties be provided at each corner of the
home with five (5) additional ties per side at
intermediate points, except that manufactured homes less
than fifty (50) feet long require only four (4)
additional ties per side~ and
c. All components of the anchoring system be
capable of carrying a force of 4,800 pounds.
C- Menufactured Home Perks and Menufectured Home Subdivisio~
When loceted within the reguletory floodplain, the following
standards are required for (a) menufectured homes not placed in
menufactured home perks or subdivisions, (b) new menufactured home
perks or subdivisions, (c) expansions to existing manufactured home
perks or subdivisions and, (d) repeir, reconstruction, or
improvements to existing menufectured home perks or subdivisions
thet equel or exceed fifty (50) percent of the velue of the
streets, utilities and peds before the repeir, reconstruction or
improvement commenced:
1. Adequate surface drainage and eccess for a hauler shall
be provided.
2. Ail manufactured homes shall be pleced on peds or lots
elevated on compected fill which shall be, at a minimum, at or
ebove the weter-surfece elevation of the base flood or on a stem
wall or on pilings so thet the bottom of the structural freme or
the lowest point of any etteched appliances, whichever is lower,
is at or above the bese flood elevation. If eleveted on pilings:
a. The lots shall be large enough to permit steps~
b. The pilings shell be placed in stable soil no
more than ten (10) feet epert and,
c. Structures designed or utilized for humen
habitation, whether full or pert time, shall only be
permitted in erees where surrounding floodwaters are less
then three (3) feet in depth or where the product of the
flow depth d, in feet, times the squere of the flow
velocity v, in feet per second, of the surrounding
floodwaters is less than or equal to the numerical velue
of eighteen (dy2 ! 18), whichever is more restrictive.
D. C rtification
Certification that the instellation of a menufactured home meets
all of the requirements of this section is required. Such
certification shell be provided by the person installing the
manufactured home, the owner, the developer of the manufactured
home perk or subdivision, or an egency regulating menufectured home
plecement, whichever is deemed eppropriete by the Town Floodplain
Administrator. Certification of elevations listed on the
Floodplain Use Permit shall be prepered by an Arizone Registered
Land Surveyor and provided to the Town Floodplain Administrator
prior to hebitetion of the structure.
SECTION 21.11 SUBDIVISION AND DEVELOPMENT REQUIREMENTS
A. Suitability of hand
Land may not be parceled or subdivided in such a manner as to
create lots unsuitable for development because of severe flood
hazards.
B. Delineation on Plats and Development Plans Areas Subject
to Floodina and Erosion
1. All tentative plats and development plans submitted shall
show location by survey, or photographic methods, of streams,
watercourses, canals, irrigation laterals, private ditches,
culverts, lakes and other water feature, including those areas
subject to flooding or erosion. The plats/plans shall also include
the direction of any flow and drainage area, as well as water
surface elevations and the limits of inundation for the base flood
if such a flood has a peak flow rate equal to or greater than 100
cfs.
2. All tentative plats and development plans shall show
proposed grading and improvements for areas which are subject to
flooding or which have extremely poor drainage and a description
and location of all facilities proposed to be used to alleviate
flooding or drainage problems, both on the proposed subdivision or
development, and downstream and upstream of any watercourse
affected by the subdivision or development, whether they are within
or outside the boundaries of the subdivision or development.
3. All development plans and tentative plats must be
accompanied by conceptual grading plans and conceptual drainage
improvement plans as necessary to demonstrate:
a. The methods for floodproofing and/or drainage
control for the development including sufficient lot
grading information to demonstrate adequate finished pad
elevations and/or drainage slopes to protect building
foundations.
b. That improvements are compatible with the
existing upstream and downstream drainage conditions and
that any proposed grading and/or grade change will not
have an adverse impact on surrounding property.
c. The methods of erosion and sediment control.
d. The methods of mitigating increased urban peak
and volumetric flood water runoff or discharge on
downstream properties created as a result of the
development.
4. Prior to commencement of any site improvements or grading,
a grading plan must be submitted to the Town of Marana for review
and approval. The standards for grading and related sitework shall
be used to prepare these plans or documents.
5. All final plats and development plans shall indicate both
the size of drainage areas and their respective 100-year peak
discharges which exceed 100 cfs, as well as the limits of the
regulatory floodplains, erosion hazard boundaries and the limits
of the federally established floodways, if contained on a Flood
Boundary Floodway Map, and be delineated in a surveyable manner and
certified by e Registered Professional Civil Engineer where any of
the portion of the land being subdivided contains areas within the
regulatory floodplain. Where floodplains are delineated the
discharge value used to establish the floodplain will be clearly
shown and, for minor watercourses, the drainage area will also be
shown.
6. The Town shall advise the county, which has assumed
jurisdiction over its floodplains in accordance with Arizona
Revised Statute 48-3610 in writing and provide a copy of any
development plan and or plats of any application for a Floodplain
Use Permit or variance to develop land in a regulatory floodplain
or floodway within one mile of the boundary of the Town. The Town
shall also advise the count~, in writing and provide a copy of any
development plan of any ma]or development proposed within a
regulatory floodplain or floodway which would affect floodplains,
floodways or watercourses within the county's area of jurisdiction.
Written notice of a copy of the plan of development shall be sent
to any adjacent jurisdiction no later than three working days after
having been received by the Town.
C. Street Elevations
Streets required for paved permanent access shall be designed and
constructed so that the flow depths over them do not exceed one
foot in depth during the base flood. At least one paved permanent
access shall be provided to each lot over terrain which can be
traversed by conventional motor vehicles in times of flooding. In
specific instances at drainage crossings where it can be
demonstrated that this requirement is either impractical, based
upon low hazard to life end property, or where construction of a
drainage crossing may create problems which override the
corresponding benefits~ this requirement may be waived by the Town
Floodplain Administrator. Fill may be used for streets in areas
subject to flooding provided such fill does not unduly increase
flood heights. The developers may be required to provide profiles
and elevations of streets for areas subject to flooding.
D. Buildin Sites
Land which contains areas within a regulatory floodplain or erosion
hazard area shall not be platted for residential occupancy or
building sites unless each lot contains a building site, either
natural or man-made, which is not subject to flooding by the base
flood.
27
1. In areas subject to flooding where no fill is proposed to
be used, the building line shall be located no closer to the
floodplain than the edge of the area subject to flooding by the
base flood.
2. In areas where fill is to be used to raise the elevation
of the building site, the building line shall be located not less
than twenty-five (25) feet landward from an~ edge of the fill. No
fill shall be placed in any floodway, no shall any fill be placed
where it diverts, retards or obstructs the flow of water to such
an extent that it creates a danger or hazard to life or property.
3. Any dwelling unit built within a regulatory floodplain
shall be constructed so as to place the minimum floor elevation of
the dwelling unit at or above the base flood elevation or at least
one foot above the highest existing natural grade if no base flood
elevation is or depths of flow are shown on the Flood Insurance
Rate Maps.
Setbacks from Channels
Along reaches of streams or watercourses where hazards from eroding
banks and/or channel meandering are considered by the Town
Floodplain Administrator to be severe, special engineering studies
shall be made by the property owner or developer and requirements
for setbacks from banks of streams or watercourses and/or other
protection measures shall be established in accordance with
findings that are concurred with by the Town Floodplain
Administrator. Also see Section 21.12.
F. Riahts-of-Wav for Drainaae
Whenever a subdivision plat or development plan contains a
watercourse which is regulated by this Code, all right-of-way
associated with the watercourse shall be designated "Drainageway".
If the watercourse is shown as an Open Space Corridor on the Town
General Plan, space for continuous and interconnected active and
passive recreational activities shall be included and so
designated.
1. If the watercourse is an improved major watercourse, the
Drainageway shall include the channel, the channel improvements,
and a fifty foot wide area measured outward from the front face of
the top of the bank protection for Pima County or Pima County Flood
Control Districts uses.
2. If the watercourse is an improved minor watercourse, the
Drainageway shall include the channel, the channel improvements,
and necessary maintenance access.
3. If the watercourse is to remain natural, the Drainageway
shall be the boundaries of the regulatory floodplain.
28
4. Along major watercourses where the peak discharge during
the base flood is 10,000 cubic feet per second or greater, the
Drainageway shall be dedicated in fee simple to the Pima County
Flood Control District.
5. Along other watercourses, the County Engineer shall
determine whether it is necessary for Pima County or the Pima
County Flood Control District to have control of the Drainageway.
If the County Engineer determines that public control is necessary,
the owner shall dedicate the Drainageway in fee simple or grant an
easement.
G. Detention/Retention Systems
(See Section 21.14 of this Code)
H. Fees and Public Cost Recovery for Drainaue or Flood Control
The Floodplain Management Board may establish a cost recovery
system and/or fee system for the improvement or installation of
public flood control systems. The purpose of the fee is to provide
a method for off-site improvements necessary to mitigate the effect
of urbanization and to provide a systematic approach for the
construction of pubic flood control improvements. If such a system
is adopted it shall demonstrate that the fee will in some manner
benefit the property from which the fee is collected and be applied
equitably to all property in proportion to floodwaters generated
by urban use of the property. The fees will also be restricted to
providing flood control improvements necessary for the allowed use
of the properties from which the fee is collected, and the fees
shall be reasonably related to the actual cost of providing flood
control improvements beneficial to the site or surrounding area.
The fees will be reviewed by the Flood Control District Advisory
Committee prior to action by the Floodplain Management Board.
SECTION 21.12 BUILDING SETBACK REQUIRENENTS AND EROSION HAZARD
AREAS
A. Major Watercourse~
For major watercourses, with 100-year peak discharges of 2,000 cfs
or greater, the following building setbacks shall be required where
bank protection is not provided.
1. Along the following major natural watercourses where no
unusual conditions exist, a minimum setback measured from the
primary channel bank or 100-year floodway, where the channel does
not contain the 100-year discharge, shall be provided at the time
of the development unless an engineering analysis which establishes
safe limits is performed by a Registered Professional Civil
Engineer and is approved by the Town Floodplain Administrator.
a. Santa Cruz River requires a setback of five
hundred (500) feet.
b. All other ma~or watercourses with 100-year
discharges greater than 10,000 cfs shall require a
setback of two-hundred and fifty (250) feet.
c. Major washes with 100-year discharges of 10,000
cfs or less, but more than 2,000 cfs, will require a
setback of one hundred (100) feet.
2. Along ma~or watercourses where unusual conditions do
exist, building setbacks shall be established on a case-by-case
basis by the Town Floodplain Administrator, unless an engineering
study which establishes safe limits is performed by a Registered
Professional Civil Engineer and is approved by the Town Engineer.
When determining building setback requirements the Town Floodplain
Administrator shall consider danger to life and property due to
existing flood heights and/or velocities and historical channel
meandering. Unusual conditions include, but are not limited to,
historical meandering of the watercourse, large excavation pits,
poorly defined or poorly consolidated banks, natural channel
armoring, proximity to stabilized structures such as bridges or
rock outcrops, and changes in the direction, amount, and velocity
of the flow of waters within the watercourse.
B. Minor Washes
For minor washes with a 100-year peak discharge of 2,000 cfs or
less, the following building setbacks shall be required where bank
protection is not provided.
1. Along minor washes where no unusual conditions exist, a
minimum building setback of fifty (50) feet measured from the
nearest primary channel bank shall be provided at the time of
development.
2. Along minor washes where unusual conditions do exist,
building setbacks shall be established on a case-by-case basis by
the Town Floodplain Administrator, unless an engineering study
which establishes safe limits is performed by a Registered
Professional Civil Engineer and is approved by the Town Engineer.
When determining building setback requirements, the Town Floodplain
Administrator shall consider danger to life and property due to
existing flood heights and/or velocities and historical channel
meandering.
SECTION 21.13 ACCESS REQUIKEMENTS
A. Purpose
It is recognized that private vehicular access may become
impassable to ordinary and emergency vehicles during times of
flooding. It is the intent of this Code to allocate the
responsibility for private vehicular access which crosses a
regulatory floodplain.
B. ADnlication of Code
This Code shall apply in all situations where private vehicular
access crosses any regulatory floodplain located between the point
where the private access leaves a paved, publicly maintained
roadway and the end of the private access.
C. Reauirements for Private Vehicular Access
In all situations where private vehicular access crosses a
regulatory floodplain located between the point where the private
access leaves a paved, publicly maintained roadway and the end of
the private access, the owner of the property requiring the private
vehicular access shall:
1. Construct a private vehicular access in such a manner that
it is permanent and is over terrain which can be traversed by
conventional motor vehicles during a base flood; or
2. Execute and record a covenant running with the land
enforceable by the Town of Marana, Pima County and the Pima County
Flood Control District which contains the following:
a. An acknowledgement that the private vehicular
access may be impassable to conventional motor vehicles
and emergency vehicles in times of flooding,
b. A hold harmless provision, holding the Town of
Marana, the Floodplain Management Board, Pima County and
the Pima County Flood Control District harmless from and
against all injuries and damages resulting from
traversing or attempting to traverse the private
vehicular access during times of flooding, and
c. A provision which either:
(1) Requires the covenantor, successors and assigns to
erect and maintain a sign(s) in a location(s) and size(s)
acceptable to the Town of Marana stating "DO NOT ENTER WHEN
FLOODED"~ or
(2) Causes the covenantor, successors and assigns to
assume responsibility to notify users of the private vehicular
access that it may be impassable in times of flooding and
agreeing to indemnify and defend the Town of Marana, the
Floodplain Management Board, Pima County, the Pima County
Flood Control District, their officers, employees, servants
and agents, against all claims for injuries to persons or
damages to property due to the construction, installation,
location, operation, safeguarding, maintenance, repair and
condition of the private vehicular access.
SECTION 21.14 DETENTION/RETENTION SYSTEMS
A. All proposed residential densities of three or more units per
acre and all proposed commercial and industrial developments
greater than one acre in size shall provide some method of peak or
volumetric runoff reduction. The amount of reduction is stipulated
within the Stormwater Detention/Retention Manual. The Stormwater
Detention/Retention Manual approved for use by the Pima County
Board of Supervisors as of the effective date of this Code is made
a part of this Code.
1. Balanced and Critical Basins
Balanced and critical drainage basins which have been identified
by the County Engineer as unsuitable for added development because
of the high probability of increased flooding, or flooding of
existing improvements or property not previously flooded, or
ponding of flood water, may be developed further only upon the
incorporation of adequate detention/retention systems or flood
control facilities as reviewed and approved by the Town Engineer.
Drainage basins which have not been previously identified as
unsuitable for additional urban development but upon any study are
so identified shall be subject to the provisions of this Section.
These detention or retention systems or flood control facilities
shall be incorporated into any and all future basin development
proposals regardless of size or land use density. The standards
for grading and related site work shall be used to prepare these
plans or documents.
2. Alternative Improvements
Structural flood control measures may be proposed in conjunction
with or in place of detention/retention systems if it can be
clearly demonstrated that such measures will not alter the water
and sediment equilibrium of the affected watercourse and will
mitigate environmental impacts. Appropriate structural flood
control measures, such as channelization to a logical conclusion
downstream of the proposed development and/or improvements to
existing off-site flood control systems within the effected
drainage or stream reach, shall be completed in accordance with
plans reviewed and approved by the Town Engineer.
3. Fees in Lieu of Detention/Retention Requirements
A fee may be utilized in place of a detention/retention system when
it can be clearly demonstrated that detention at the site does not
provide off-site flood relief due to the parcel size, location
within the drainage basin, or other factors. The fees collected
will be used to construct public flood control improvements which
will mitigate the potential damage of flood waters originating from
the property contributing the fees. In balanced and critical
basins, and where development is less than three units to the acre,
use of a fee system will be encouraged in lieu of a detention
system in order to preserve the natural drainage patterns. Any fee
system shall be approved by Resolution of the Floodplain Management
Board.
4. Balanced and Critical Basin Map
The Town Floodplain Administrator shall retain for public
inspection and use an official map prepared by the County Engineer
designating balanced and critical basins within the Town of Marana.
SECTION 21.15 SEDIMENT AND E~OSION COMXKOL
A. Gradina
Any grading and alteration of a watershed tributary to any
watercourse regulated by this Code shall be controlled to minimize
the loss of soil through erosion from rainfall or storm water
flowage. Methods to control erosion and sedimentation must be
demonstrated to the satisfaction of the Town Engineer prior to the
granting of a Floodplain Use Permit for any work in any flood
hazard zone or floodplain. Both temporary and permanent measures
for sediment and erosion control must be clearly delineated on
plans or other written documents prior to receiving a Floodplain
Use Permit. The Standards for Grading and Related Site Work shall
be used to prepare these plans or documents.
B. Soil Investigations
The Town Engineer may require appropriate soil investigation
reports for the purpose of determining the erosive properties of
areas or lands to be graded or disturbed which may create sediment
deposition or erosion in any watershed regulated by this Code.
C. Annlicability
Any activity which may have an effect on the flood water carrying
capacity of any watercourse in any watershed in the Town of Marana
is subject to the provisions of this Section.
SECTION 21.16 APPEALS
A. Appeals Process
Any property owner appealing any decision concerning the
interpretation or administration of this Code shall first appeal
in writing to the Town Engineer. The Town Engineer may hold
hearings and request such additional information as he deems
necessary in order to render his decision. The Town Engineer shall
render a decision within 15 days of receiving such additional
information.
Any property owner aggrieved by the decision of the Town Engineer
may then appeal to the Town of Marana Floodplain Management Board
through the Town Floodplain Administrator within thirty (30) days
of the date written notice of the decision of the Town Engineer is
mailed to the property owner at the address listed by him in his
appeal.
B. Procedures for Public HeariD~
1. Upon receipt, in proper form, of the appeal, the
Floodplain Management Board shall hold a public hearing concerning
the appeal not more than forty-five (45) days nor less than fifteen
(15) days after the filing.
2. The appeal shall contain a detailed explanation of all
matters in dispute and the Floodplain Management Board through the
Town Floodplain Administrator may require the submission of such
additional information as it deems necessary.
3. The Floodplain Management Board shall render its decision
within thirty (30) days of the close of the hearing.
4. The Floodplain Management Board may meet monthly or at
such times as it deems necessary for the transaction of business
including the hearing of appeals.
5. The Floodplain Management Board may refer matters of a
highly technical nature, where an appeal is made to the Town
Engineer for interpretation, the Town Engineer may refer the matter
to a technical review board which shall make findings and
recommendations to the Town Engineer for decision. The technical
review board shall consist of three Registered Professional Civil
Engineers, one named by the Town Floodplain Administrator, one
named by the appellant, and one named by the first two members.
This review board shall not be permanent in nature, but shall be
formed as required to hear individual appeals. All costs of the
technical review board shall be borne by the property owner.
SECTION 21.17 VARIANCES
A. Authorization
The Floodplain Management Board shall hear and decide all requests
for variances from the requirements of this Code to the extent
permitted by Arizona Revised Statute 48-3609.
B. Reauirements for a Variance
Variances shall only be issued if the Floodplain Management Board
makes the following five determinations:
1. A determination that the variance is the minimum
necessary, considering the flood hazards to afford relief;
2. A determining of good and sufficient cause;
3. A determination that failure to grant the variance would
result in exceptional hardship to the applicant; and
4. A determination that the granting of the variance will not
create a danger or hazard to life or property in the area or result
in increased flood heights, additional threats to public safety,
the creation of a nuisance, the victimization of or fraud on the
public, or that the variance is not in conflict with other local
laws or ordinances.
5. Special circumstances, such as size, shape, topography,
location or surrounding of the property, would cause strict
application of the regulations to deprive the property of the
privileges enjoyed by similar property in a regulatory floodplain
or erosion hazard area. A variance is subject to conditions to
ensure that the variance does not constitute a grant of special
privileges inconsistent with the limitations on similar property
in the regulatory floodplain.
C. Covenants
Upon granting of a variance, permit or waiver for the construction
of a dwelling unit or commercial or industrial structure, where the
construction of such unit or structure is otherwise contrary to
this Code, the Floodplain Management Board shall provide written
notice to the grantees of such a variance, permit, or waiver that,
if the structure is a dwelling unit or business as defined by
A.R.S. 26-321, the land upon which the structure is located is
ineligible for exchange of state land pursuant to the flood
relocation and land exchange program provided for by Title 26,
Chapter 2, Article 2. A copy of the notice shall be recorded by
the Floodplain Management Board in the office of the County
Recorder and shall be recorded in manner so that it appears in the
chain of title of the affected parcel of land.
D. Notification of Adjacent Jurisdictions
The Town shall advise the county which has assumed jurisdiction
over its regulatory floodplains in accordance with Arizona Revised
Statute No. 48-3610 in writing and provide a copy of any
development plan of any application for a Floodplain Use Permit or
variance to develop land in a regulatory floodplain or floodway
within one mile of the Town's boundary. The Town shall also advise
the county in writing and provide a cody of any development plan
of any major development proposed within a regulatory floodplain
or floodway which would affect floodplains, floodways or
watercourses within the county's area of jurisdiction. Written
notice and a copy of the plan of development shall be sent to any
adjacent jurisdiction no later than three working days after having
been received by the Town.
SICTION 21.18 AMENDMENTS
A. Public Hearing Proces~
This Code may be amended only after a public hearing at which
parties in interest and other citizens have an opportunity to be
heard.
B. Petition for Amendments
The Town Floodplain Administrator or any affected person may
petition for an amendment to this Code and shall initiate such
proceeding by filing with the Floodplain Management Board a proper
and complete petition for such change on the form or forms provided
by the Floodplain Management Board.
1. Staff Report: Upon receipt of such petition the Town
Floodplain Administrator, with the assistance, advice and counsel
of the other appropriate Town Departments, shall make a study and
report the findings to the Floodplain Management Board. The report
shall be made available to the applicant and other interested
parties at least ten (10) days before the date of any public
hearing for the respective petition.
2. Floodplain Management Board Action: Upon receipt of the
Town Floodplain Administrator's report and recommendation, the
Floodplain Management Board shall hold a public hearing thereon at
which petitioner and other parties in interest have an opportunity
to be heard. At least thirty (30) days prior to the hearing, a
notice of the time and place of hearing shall be published in a
newspaper of general circulation within the area of jurisdiction
of the Floodplain Management Board; or, if no newspaper of general
circulation is regularly published within the area of jurisdiction,
a newspaper of general circulation regularly published nearest the
area of jurisdiction. A notice of any hearing accompanied by e
copy of each of the proposed amendments shall be furnished to the
Director of the Arizona Department of Water Resources at least
thirty (30) days prior to the date of such hearing. A copy of any
amendment adopted by the Floodplain Management Board shall within
five (5) days thereafter be filed with the Director of the Arizona
Department of Water Resources.
SECTION 21.19 UN~ANFUL ACTS, PENALTY
A. Unlawful Acts
It is unlawful for any person to divert, retard or obstruct the
flow of waters in the regulatory floodplain without first securing
the permit required by any provision of this Code.
B. Penalty
Any person or entity violating the provisions of this Code shall
be guilty of a Class i misdemeanor.
SECTION 21.20 MISCELI~ANEOUS
A. Cooperative Aareements and Consultants
The Floodplain Management Board may retain consultants and experts
and may enter into cooperative agreements for the delineation of
floodplains and floodways and for such other assistance and
guidance considered appropriate and necessary.
This Code and the various parts thereof are hereby declared to be
severable. Should any section or paragraph of this Code be
declared by the court to be unconstitutional or invalid, such
decision shall not affect the validity of the Code as a whole, or
any portion thereof other than the section or paragraph declared
to be unconstitutional or invalid.
C. Units of Measure
All units of measure contained in this Code, whether expressed or
implied, are intended to be in the English system of units.
D. Fees
Non-refundable review fees as determined by Town Council Resolution
shall accompany Floodplain Use Permit applications, appeals,
variances, amendments, reports, studies and plans including but not
limited to hydrologic, hydraulic, floodplain, erosion,
sedimentation, geomorphic analyses, structural flood control, soils
investigation, detention/retention systems, setback and hazard
areas.
37
APPENDIX i TABLE OF REGULATORY PEAK DISCHARGES
TABLE OF REGULATORY PEAK DISCHARGE~
Note: List is not all inclusive; remaining watersheds are also
subjected to Marana Floodplain and Erosion Hazard Management Code
Restrictions. Listed discharges are subject to review and revision
due to urbanization and improvements; check with the Town Engineer
before their use.
Blanco Wash · Los Robles Wash
Brawley Wash O Los Robles Wash
Hardy Wash ~ Camino De Oeste Road
Little Brawley Wash ~ 32o 7' 25"
111° 19' 45"
Los Robles Wash ~ Blanco Wash
Picture Rock Wash e Picture Rocks Road
Santa Cruz River O Cortaro Road
Tortolita Fan
Canada Aqua Canyon ~ 1-10
Cochie Canyon ~ 1-10
Cottonwood Canyon ~ 1-10
Derrio Canyon ~ 1-10
Eastern Limit of Fan ~ 1-10
Guild Canyon · 1-10
Ruelas Canyon · 1-10
Prospect Canyon O 1-10
Wild Burro ~ 1-10
REGULATORY DESIGN
17,000 22,000
35,000 40,000
4,536
13,440
37,000 42,000
3,479
70,000 80,000
5,255
5,779
5,439
5,229
4,084
4,561
4,604
4,340
5,831
Unless otherwise noted, design discharges shall be 20 percent
greater than regulatory discharges.