Chapter
12
DRAINAGE
AND FLOOD CONTROL[1]
Art.
I. In General, §§ 12-112-15
Art.
II. Floodplain Management, §§
12-1612-35
Art.
III.
Art.
IV. Storm Water Retention, §§
12-5612-100
Div.
1. Generally, §§ 12-5612-70
Div.
2. Administration, §§ 12-7112-85
Div.
3. Standards and Specifications, §§
12-8612-100
Art.
V. Storm Water System Extension
Policy, §§ 12-10112-105
Art.
VI. Storm Water Pollution
Control, §§ 12-11512-152
Div. 1. General Provisions, §§ 12-11512-124
Div.
2. Prohibitions and Controls to Reduce
the Discharge of Pollutants
in
Storm water, §§ 12-12512-134
Div.
3. Compliance Monitoring, §§
12-13512-144
Div.
4. Enforcement, §§ 12-14512-152
ARTICLE
I. IN GENERAL
Secs.
12-112-15. Reserved.
ARTICLE
II. FLOODPLAIN MANAGEMENT [2]
Sec.
12-16. Purpose.
(a) The flood hazard areas of
(b) These flood losses are caused by the
cumulative effect of obstructions in areas of special flood hazard which increase
flood heights and velocities, and, when inadequately anchored, damage uses in
other areas. Uses that are inadequately
floodproofed, elevated or otherwise protected from flood damage also contribute
to the flood loss.
(c) It is the purpose of this article to
promote the public health, safety and general welfare, and to minimize public
and private losses due to flood conditions in specific areas by provisions
designed:
(1) To protect human life and health;
(2) To minimize expenditure of public money for
costly flood-control projects;
(3) To
minimize the need for rescue and relief efforts associated with flooding and
generally undertaken at the expense of the general public;
(4) To minimize prolonged business interruptions;
(5) To minimize damage to public facilities and utilities, such as
water and gas mains, electric, telephone and sewer lines, and streets and
bridges, located in areas of special flood hazard;
(6) To help maintain a stable tax base by providing for the second
use and development of areas of special flood hazard so as to minimize future
flood blight areas;
(7) To ensure that potential buyers are notified that property is in
an area of special flood hazard;
(8) To ensure that those who occupy the areas of special flood
hazard assume responsibility for their actions; and
(9) To maintain eligibility for state disaster relief.
(Ord. No. 87.25, 9-10-87)
Sec.
12-17. Methods of reducing flood losses.
In order to
accomplish its purposes, this article includes methods and provisions for:
(1) Restricting or prohibiting uses which are dangerous to health,
safety and property due to water or erosion hazards, or which result in
damaging increases in erosion or in flood heights or velocities;
(2) Requiring that uses vulnerable to floods, including facilities
which serve such uses, be protected against flood damage at the time of initial
construction;
(3) Controlling the alteration of natural floodplains, stream
channels and natural protective barriers, which help accommodate or channel
floodwaters;
(4) Controlling filling, grading, dredging and other development
which may increase flood damage; and
(5) Preventing or regulating the construction of flood barriers
which will unnaturally divert floodwaters or which may increase flood hazards
in other areas.
(Ord. No. 87.25,
Sec.
12-18. Definitions.
Unless specifically
defined below, words or phrases used in this article shall be interpreted so as
to give them the meaning they have in common usage and to give this article its
most reasonable application:
Appeal means
a request for a review of the floodplain administrator's interpretation of any
provision of this article.
Area of shallow flooding means a designated AO Zone on the flood insurance rate map (FIRM).
The base flood depths range from one to three (3) feet, a clearly defined
channel does not exist, the path of flooding is unpredictable and
indeterminate, and velocity flow may be evident.
Base flood means
the flood having a one percent chance of being equaled or exceeded in any given
year.
Breakaway wall means
a wall that is not part of the structural support of the building and is
intended through its design and construction to collapse under specific lateral
loading forces without causing damage to the elevated portion of the building
supporting foundation system.
Critical feature means
an integral and readily identifiable part of a flood protection system without
which the flood protection provided by the entire system would be compromised.
Development means
any man-made change to improved or unimproved real estate, including, but not
limited to, buildings or other structures, mining, dredging, filling, grading,
paving, excavation or drilling operations or storage of equipment or materials.
Financial assistance means any form of loan, grant, guaranty, insurance, payment,
rebate, subsidy, disaster assistance loan or grant, or any other form of direct
or indirect federal assistance, other than general or special revenue sharing
or formula grants made to states.
Flood or
flooding means a general and
temporary condition of partial or complete inundation of normally dry land
areas from the overflow of flood water; the unusual and rapid accumulation or
runoff of surface waters from any source; or the collapse or subsidence of land
along the shore of a body of water as a result of an unanticipated force of
nature, such as flash flood, or by some similarly unusual and unforeseeable
event which results in flooding as defined in this definition.
Flood boundary floodway map means the official map on which the
Federal Insurance Administration has delineated both the areas of flood hazard
and the floodway.
Flood insurance rate map (FIRM) means the official map on which the
Federal Insurance Administration has delineated both the areas of special flood
hazards and the risk premium zones applicable to the community.
Flood insurance study means the official report provided by the Federal Insurance
Administration that includes flood profiles, the FIRM, the flood boundary
floodway map, and the water surface elevation of the base flood.
Floodplain or
flood-prone area means any land area
susceptible to being inundated by water from any source (see definition of
"Flooding").
Floodplain administrator means the city engineer of the city who is hereby authorized
by the floodplain board to administer the provisions of this article.
Floodplain board means
the city council of the city at such times as they are engaged in the
enforcement of this article.
Floodplain management means the operation of an overall program of corrective and
preventive measures for reducing flood damage, including, but not limited to,
emergency preparedness plans, flood-control works and floodplain management
regulations.
Floodplain management regulations means zoning ordinances, subdivision
regulations, building codes, health regulations, special purpose ordinances
(such as floodplain ordinances, grading ordinances and erosion control
ordinances) and other applications of police power. The term describes such
state or local regulations in any combination thereof which provide standards
for the purpose of flood damage prevention and reduction.
Flood proofing means
any combination of structural and nonstructural additions, changes or
adjustments to structures which reduce or eliminate flood damage to real estate
or improved real property, water and sanitary facilities, structures and their
contents.
Flood protection system means those physical structural works for which funds have
been authorized, appropriated and expended, and which have been constructed
specifically to modify flooding in order to reduce the extent of the area
within a community subject to a "special flood hazard" and the extent
of the depths of associated flooding.
Such a system typically includes dams, reservoirs, levees or dikes. These specialized flood modifying works are
those constructed in conformance with sound engineering standards.
Flood-related erosion means the collapse or subsidence of land along a body of
water as a result of an unanticipated force of nature, such as a flash flood,
or by some similarly unusual and unforeseeable event which results in flooding.
Floodway means
the channel of a river or other watercourse and the adjacent land areas
necessary in order to discharge the 100-year flood without cumulatively
increasing the water surface elevation.
Functionally dependent use means a use which cannot perform its
intended purpose unless it is located or carried out in close proximity to
water. The term includes only docking
facilities, port facilities that are necessary for the loading and unloading of
cargo or passengers, and ship building and ship repair facilities, but does not
include long-term storage or related manufacturing facilities.
Highest adjacent grade means the highest natural elevation of the ground surface
prior to construction next to the proposed walls of a structure.
Historic structure means a structure
listed on the National Register of Historic Places or in a state or local
inventory of historic places.
Levee means
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.
Levee system means
a flood protection system which consists of a levee, or levees, and associated
structures, such as closure and drainage devices, which are constructed and
operated in accordance with sound engineering practices.
Lowest floor means the lowest floor of
the lowest enclosed area (including basement). An unfinished or flood-resistant
enclosure, usable solely for parking of vehicles, building access or storage,
in an area other than a basement area is not considered a building's lowest
floor; provided, that such enclosure is not built so as to render the structure
in violation of the applicable nonelevation design requirements of this
article.
Manufactured home means
a structure, transportable in one or more sections, which is built on a
permanent chassis and is designed for use with or without a permanent
foundation when connected to the required utilities. The term "manufactured home" does
not include a "recreational vehicle".
Manufactured home park or subdivision means a parcel (or contiguous parcels) of
land divided into two (2) or more manufactured home lots for sale or rent.
Mean sea level means,
for purposes of the National Flood Insurance Program, the National Geodetic
Vertical Datum (NGVD) of 1929 or other datum to which base flood elevations
shown on a community's flood insurance rate map are referenced.
New construction means,
for floodplain management purposes, structures for which the "start of
construction" commenced on or after the effective date of a floodplain
management regulation adopted by a community and includes any subsequent
improvements to such structures.
Person means
an individual or his agent, a firm, partnership, association or corporation or
agent of the aforementioned groups, or this state or its agencies or political
subdivisions.
Program means
the National Flood Insurance Program authorized by 42 U.S.C. §§ 40014128.
Program deficiency means
a defect in a community's floodplain management regulations or administrative
procedures that impairs effective implementation of those floodplain management
regulations or of the NFIP standards.
Recreational vehicle means a vehicle
which is (1) built on a single chassis, (2) four hundred (400) square feet or
less when measured at the largest horizontal projection, (3) designed to be
self-propelled or permanently towable by a light duty truck, and (4) designed
primarily not for use as a permanent dwelling but as temporary living quarters
for recreational, camping, travel or seasonal use.
Regulatory flood-elevation means an elevation one foot above the
base flood elevation indicated on the FIRM. For example, buildings in Zone
"AO (one foot depth)" are required to have the lowest floor two (2)
feet higher than the highest adjacent grade.
Remedy a violation means
to bring the structure or other development into compliance with state or local
floodplain management regulations, or, if this is not possible, to reduce the
impacts of its noncompliance. Ways that
impacts may be reduced include protecting the structure or other affected
development from flood damages, implementing the enforcement provisions of this
article or otherwise deterring future similar violations, or reducing federal
financial exposure with regard to the structure or other development.
Riverine means
relating to, formed by, or resembling a river (including tributaries), stream,
brook, etc.
Special flood hazard area means an area having special flood or flood-related erosion
hazards, and shown on an FHBM or FIRM as Zone A, AO, A1-30, AE, A99 or AH.
Start of construction includes substantial improvement, and means the date the
building permit was issued, provided the actual start of construction, repair,
reconstruction, rehabilitation, addition, placement or other improvement was
within one hundred eighty (180) days of the permit date. The actual start means either the first
placement of permanent construction of a structure on a site, such as the
pouring of slabs or footings, the installation of piles, the construction of
columns or any work beyond the stage of excavation, or the placement of a
manufactured home on a foundation. Permanent construction does not include land
preparation, such as clearing, grading and filling; nor does it include the
installation of streets or walkways; nor does it include excavation for a
basement, footings, piers, or foundations or the erection of temporary forms;
nor does it include the installation on the property of accessory buildings,
such as garages or sheds, not occupied as dwelling units or not part of the
main structure. For a substantial
improvement, the actual start of construction means the first alteration of any
wall, ceiling, floor or other structural part of a building, whether or not
that alteration affects the external dimensions of the building.
Structure means
a walled and roofed building, including a gas or liquid storage tank, that is
principally above ground, as well as a manufactured home.
Substantial damage means damage of any
origin sustained by a structure whereby the cost of restoring the structure to
its before damaged condition would equal or exceed fifty percent (50%) of the
market value of the structure before the damage occurred.
Substantial improvement means any repair, reconstruction, rehabilitation, addition
or improvement of a structure, the cost of which equals or exceeds fifty
percent (50%) of the market value of the structure before the "start of
construction" of the improvement.
This term includes structures which have incurred "substantial
damage", regardless of the actual repair work performed. The term does not, however, include either:
(1) Any project for improvement of a structure to correct existing
violations of state or local health, sanitary or safety code specifications
which have been identified by the local code enforcement official and which are
the minimum necessary to assure safe living conditions; or
(2) Any alteration of a "historic structure", provided
that the alteration will not preclude the structures continued designation as
a "historic structure".
Variance means
a grant of relief from the requirements of this article which permits construction
in a manner that would otherwise be prohibited by this article.
Violation means
the failure of a structure or other development to be fully compliant with the
community's floodplain management regulations.
A structure or other development without the elevation certificate,
other certifications, or other evidence of compliance required in this article
is presumed to be in violation until such time as that documentation is
provided.
(Ord. No. 87.25, 9-10-87; Ord. 2005.67, 9-29-05)
Sec.
12-19. Compliance and jurisdiction of
this article.
(a) This article shall apply to all areas of
special flood hazards within the corporate limits of
(b) Within a delineated floodplain, the
development services department shall not issue a building permit until receipt
of notification from the floodplain administrator that all plans have been
reviewed and approved for conformance with this article.
(c) Within a
delineated floodplain, the development services department shall not issue a
certificate of occupancy until receipt of notification from the floodplain
administrator that all construction has been completed in conformance with this
article.
(Ord. No. 87.25,
Sec.
12-20. Basis for establishing the areas
of special flood hazard.
The area of
special flood hazard identified by the Federal Emergency Management Agency
(FEMA) in a scientific and engineering report entitled "The Flood
Insurance Study for Maricopa County and Incorporated areas" dated July 19,
2001, with an accompanying flood insurance rate map and all subsequent
amendments or revisions are adopted by reference and declared to be a part of
this article. The flood insurance study
and the flood insurance rate maps are on file at the city engineering
office. The flood insurance study is the
minimum area of applicability of this article and may be supplemented by
studies for other areas which allow implementation of this article and which
are recommended to the floodplain board by the floodplain administrator. The floodplain board, within its area of
jurisdiction shall delineate (or may, by rule, require developers of land to
delineate) for areas where development is ongoing or imminent, and thereafter
as development becomes imminent, floodplains consistent with the criteria
developed by FEMA and the director of water resources.
(Ord. No. 87.25, 9-10-87; Ord. No. 2005.67, 9-29-05)
Sec.
12-21. Abrogation and greater
restrictions.
This article
is not intended to repeal, abrogate or impair any existing easements, covenants
or deed restrictions. However, where
this article and another ordinance, easement, covenant or deed restriction
conflict or overlap, whichever imposes the more stringent restrictions shall
prevail.
(Ord. No. 87.25,
Sec.
12-22. Interpretation.
In the interpretation
and application of this article, all provisions shall be considered as minimum
requirements, liberally construed in favor of the governing body, and deemed
neither to limit nor repeal any other powers granted under state statutes.
(Ord. No. 87.25,
Sec.
12-23. Warning and disclaimer of
liability.
The degree of
flood protection required by this article is considered reasonable for regulatory
purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare
occasions. Flood heights may be
increased by man-made or natural causes.
This article does not imply that land outside the areas of special flood
hazards or uses permitted within such areas will be free from flooding or flood
damages. This article shall not create
liability on the part of the city, any officer or employee thereof, or the
Federal Insurance Administration for any flood damages that result from
reliance on this article or any administrative decision lawfully made
thereunder.
(Ord. No. 87.25,
Sec. 12-24. Statutory exemptions.
(a) In accordance
with A.R.S. § 48-3609, nothing in this article shall:
(1) Affect existing uses of property or the right to continuation of
the use under conditions which existed on the effective date of this article;
(2) Affect repair or alteration of property for the purposes for
which such property was used on the effective date of this article; providing
such repair or alteration does not exceed fifty percent (50%) of the value of
the property prior to the repair or alteration; and provided the repair or
alteration does not decrease the carrying capacity of the watercourse; or
(3) Affect or apply to facilities constructed or installed pursuant
to a certificate or environmental compatibility issued under the authority of
Title 40, Chapter 2, Article 6.2.
(b) In accordance with A.R.S. § 48-3613,
written authorization shall not be required, nor shall the floodplain board
prohibits:
(1) The construction of bridges, culverts, dikes and other
structures necessary to the construction of public highways, roads and streets
intersecting a watercourse;
(2) The construction of structures on banks of a creek, stream,
river, wash, arroyo or other watercourse to prevent erosion of or damage to
adjoining land, or dams for the conservation of floodwaters as permitted by
Title 48, Chapter 21;
(3) Construction of tailing dams and waste disposal areas for use in
connection with mining and metallurgical operations. This paragraph does not exempt those sand and
gravel operations which will divert, retard or obstruct the flow of waters in
any watercourse; or
(4) Any flood-control district, or other political subdivision, from
exercising powers granted to it under Title 45, Chapter 10, Arizona Revised
Statutes.
(c) Before any construction authorized by paragraph
(b) above may begin, the responsible person must submit plans for the
construction to the floodplain administrator for review and comment.
(d) These exemptions do not preclude any person
from liability if that person's actions increase flood hazards to any other
person or property.
(Ord. No. 87.25,
Sec.
12-25. Violations.
(a) It is unlawful for any person to divert,
retard or obstruct the flow of waters in any watercourse whenever it creates a
hazard to life or property.
(b) Violators of this article shall be notified
in writing by the city engineer. The
notice, which shall be sent by certified mail or personally served, shall state
specifically the nature of the violation and request that it be corrected. If a violation is not corrected within thirty
(30) days after notice, the city engineer shall promptly hand over all
pertinent facts to the city attorney with a request for prosecution under the
provisions of this article. Any persons
violating any of the provisions of this article shall be guilty of a
misdemeanor and punishable as set forth in § 1-7 of this code.
(c) If attempts to abate the violation are
unsuccessful, the floodplain administrator shall submit to the administrator of
Federal Insurance Administration a declaration for denial of insurance, stating
that the property is in violation of a cited state or local law, regulation or
ordinance, pursuant to § 1316 of the National Flood Insurance Act of 1968, as
amended.
(Ord. No. 87.25,
Sec.
12-26. Severability.
The ordinance
from which this article is derived, and the various parts thereof, are hereby
declared to be severable. Should any
section of this article be declared by the courts to be unconstitutional or
invalid, such decision shall not affect the validity of the article as a whole
or any portion thereof other than the section so declared to be
unconstitutional or invalid.
(Ord. No. 87.25,
Sec.
12-27. Establishment of floodplain
permit.
A floodplain
permit shall be obtained before construction or development begins within any
special flood hazard area. Application
for a floodplain permit shall be made on forms furnished by the floodplain
administrator and may include, but not be limited to, plans, in duplicate,
drawn to scale, showing the nature, location, dimensions and elevation of the
area in question; existing or proposed structures, fill, storage of materials,
drainage facilities; and the location of the foregoing. Specifically, the
following information is required:
(1) Proposed
elevation, in relation to mean sea level, of the lowest floor (including
basement) of all structures; in Zone AO, elevation of existing grade and
proposed elevation of lowest floor of all structures;
(2) Proposed
elevation, in relation to mean sea level, to which any structure will be
floodproofed;
(3) Certification
by a registered professional engineer or architect that the floodproofing
methods for any nonresidential structure meet the floodproofing criteria in §
12-29(c); and
(4) Description
of the extent to which any watercourse will be altered or relocated as a result
of proposed development.
(Ord. No. 87.25, 9-10-87; Ord. 2005.67, 9-29-05)
Sec. 12-28. Designation, duties and responsibilities of
the floodplain administrator.
(a) Designation. The floodplain administrator is hereby
designated as enforcing officer for this article and is hereby authorized and
directed to formulate the procedures and criteria necessary to carry out its
intent. He may adopt a fee schedule for
review of applications for permits and variances from the requirements of this
article.
(b) Duties
and responsibilities. Duties of the
floodplain administrator or his designee shall include, but not be limited to:
(1) Review all floodplain permits to determine that:
a. The permit requirements of this article
have been satisfied;
b. All other required state and federal
permits relating to floodplains and
floodways have been obtained;
c. The site is reasonably safe from flooding;
and
d. The proposed development does not
adversely affect the carrying capacity of the floodway. For purposes of this article, "adversely
affects" means that the cumulative effect of the proposed development,
when combined with all other existing and anticipated development within
(2) Use of other base flood
data. When base flood elevation data
has not been provided in accordance with § 12-20, the floodplain administrator
shall obtain, review and reasonably utilize any base flood elevation data
available from a federal, state or other source in order to administer this
article. Any such information shall be
submitted to the floodplain board for adoption.
(3) Obtain and maintain for public inspection and make available as
needed for flood insurance policies:
a. The certified elevation required in §
12-29(c)(1);
b. The certification required in §
12-29(c)(2);
c. The floodproofing certification required
in § 12-29(c)(3); and
d. The certified elevation required in §
12-32(b).
(4) Whenever a watercourse is to be altered or relocated:
a. Notify adjacent communities and the
Arizona Department of Water Resources prior to such alteration or relocation of
a watercourse, and submit evidence of such notification to the Federal
Insurance Administration; and
b. Require that the flood-carrying capacity
of the altered or relocated portion of said watercourse is maintained.
(5) Within one hundred twenty (120) days after completion of
construction of any flood control protective works which change the rate of
flow during the flood or the configuration of the floodplain upstream or
downstream from or adjacent to the project, the person or agency responsible
for installation of the project shall provide to the governing bodies of all
jurisdictions affected by the project a new delineation of all floodplains
affected by the project. The new
delineation shall be done according to the criteria adopted by the Director of
the Department of Water Resources of the State of
(6) Base flood elevations may increase or decrease resulting
from physical changes affecting flooding conditions. As soon as practicable, but not later than
six (6) months after the date such information becomes available, the city
floodplain administrator shall notify FEMA of the changes by submitting
technical or scientific data in accordance with volume 44 of the Code of
Federal Regulations, § 65.3. Such a
submission is necessary so that upon confirmation of those physical changes
affecting flooding conditions, risk premium rates and floodplain management
requirements will be based upon current data.
(7) Advise the Flood Control District of Maricopa County and any
adjunct jurisdiction having responsibility for floodplain management in writing
and provide a copy of the development plans included with all applications for
floodplain use permits to develop land in a floodplain or floodway within one
mile of the corporate limits of the city.
Also, advise the Flood Control District of Maricopa County in writing
and provide a copy of any development plan of any major development proposed
within a floodplain or floodway which could affect floodplains, floodways or
watercourses within the district's area of jurisdiction. Written notice and a copy of the plan of
development shall be sent to the district no later than three (3) working days
after having been received by the floodplain administrator.
(8) Make interpretations where needed as to the exact location of
the boundaries of special flood hazard areas (for example, where there appears
to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the
boundary shall be given a reasonable opportunity to appeal the interpretation
as provided in § 12-35.
(9) Take actions on violations of this article as required in §
12-25 herein.
(Ord. No. 87.25, 9-10-87; Ord. 2005.67, 9-29-05)
Sec.
12-29. Standards of construction.