HomeMy WebLinkAboutORD 6084CITY OF RENTON, WASHINGTON
ORDINANCE NO. 6084
AN ORDINANCE OF THE CITY OF RENTON, WASHINGTON, AMENDING FLOOD
REGULATIONS IN SUBSECTIONS 4-3-050.G.4.d AND 4-3-050.G.4.e OF THE
RENTON MUNICIPAL CODE, AUTHORIZING CORRECTIONS, PROVIDING FOR
SEVERABILITY, AND ESTABLISHING AN EFFECTIVE DATE.
WHEREAS, the City seeks to revise Critical Areas Regulations to comply with 2021 updates
to the FEMA National Flood Insurance Program (NFIP) Community Rating System (CRS) voluntary
incentive program requirements so that Renton residents may be qualified for discounted flood
insurance premium rates; and
WHEREAS, this matter was duly referred to the Planning Commission for investigation
and study, and the matter was considered by the Planning Commission; and
WHEREAS, pursuant to RCW 36.70A.106, on August 12, 2022, the City notified the State
of Washington of its intent to adopt amendments to its development regulations; and
WHEREAS, the Planning Commission held a public hearing on September 7, 2022,
considered all relevant matters, and heard all parties in support or opposition, and subsequently
forwarded a recommendation to the City Council;
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF RENTON, WASHINGTON, DO
ORDAIN AS FOLLOWS:
SECTION I. All portions of the Renton Municipal Code in this ordinance not shown in
strikethrough and underline edits or are not explicitly repealed herein remain in effect and
unchanged.
ORDINANCE NO. 6084
SECTION II. Subsections 4-3-050.G.4.d and 4-3-050.G.4.e of the Renton Municipal
Code (RMC) are amended as shown below. All other provisions in 4-3-050.G.4 remain in effect
and unchanged.
d. Specific Standards: In all flood hazard areas, the following provisions
are required:
i. Residential Construction:
(a) In AE and Al-30 zones or other A zoned areas where the base
flood elevation has been determined or can be reasonably obtained, new
construction and substantial improvement of any residential structure shall have
the lowest floor, which for the purposes of this section includesc"^s
basement or —arid attached garage as described in RMC 4-3-050.G.4.d.i.e.4
elevated one foot (1') or more above the base flood elevation. Mechanical
equipment, ductwork, and utilities shall be wateFpMef elevated at least one
foot (1') above the base flood elevation.
(b) New construction and substantial improvement of any
residential structure in an AO zone shall meet the requirements in Appendix A,
attached to the ^rd"^,^rP r„d;f;ed this S^^+i^^ Ordinance 5977, or superseding
Ordinances.
(c) New construction and substantial improvement of any
residential structure in an Unnumbered A zone, for which a base flood elevation
is not available and cannot be reasonably obtained, shall be reasonably safe from
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ORDINANCE NO. 6084
flooding, but in all cases the lowest floor and any attached garage floor shall be at
least two feet (2') above the Highest Adjacent Grade.
(d) If buildings or manufactured homes are constructed or
substantially improved with fully enclosed areas below the lowest floor, the areas
shall be used solely for parking of vehicles, building access, or storage.
(e) Fully enclosed areas below the lowest floor that are subject
to flooding are prohibited, or shall be designed to automatically equalize
hydrostatic flood forces on exterior walls by allowing for the entry and exit of
floodwaters. Designs for meeting this requirement must meet or exceed the
following minimum criteria:
(1) Have a minimum of two (2) openings with a total net
area of not less than one (1) square inch for every square foot of enclosed area
subject to flooding; and
(2) The bottom of all openings shall be no higher than one
foot (1') above grade; and
(3) Openings may be equipped with screens, louvers,
valves, or other coverings or devices provided that they permit the automatic
entry and exit of floodwater; and
(4) A garage attached to a residential structure, constructed
with the garage floor slab below the base flood elevation, must be designed to
allow for the automatic entry and exit of floodwaters.
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ORDINANCE NO.6084
Alternatively, a registered engineer or architect may design and
certify engineered openings.
ii. Manufactured Homes:
(a) All manufactured homes to be placed or substantially
improved within Zones Al-A30, AH, and AE on the community's Flood Insurance
Rate Map FIRM shall be elevated on a permanent foundation such that the
lowest floor of the manufactured home is elevated a minimum of one foot (V)
above the base flood elevation and be secured to an adequately anchored
foundation system to resist flotation, collapse and lateral movement. Mechanical
equipment, ductwork, and utilities shall be elevated at least one foot W) above
the base flood elevation.
(b) Manufactured homes to be placed or substantially
improved on sites in an existing manufactured home park or subdivision within
Zones Al-30, AH, and AE on the community's FIRM that
are not subject to the above manufactured home provisions shall be elevated so
that e her —the lowest floor of the manufactured home is elevated a minimum of
one foot (V) above the base flood elevation er the M „fa .t„rnrl h.eme ehass6s it
Strength that -are nn Inrr than thirtySOX iRehes (36") in height abe _ ade-and be
secured to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement. Mechanical equipment, ductwork, and utilities shall be
elevated at least one foot W) above the base flood elevation.
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ORDINANCE NO. 6084
(c) If buildings or manufactured homes are constructed or
substantially improved with fully enclosed areas below the lowest floor, the areas
shall be used solely for parking of vehicles, building access, or storage.
iii. Nonresidential Construction: New construction or substantial
improvement of any commercial, industrial,or other nonresidential structure shall
meet the requirements of subsection G4diii(a) or G4diii(b) of this Section:
(a) New construction or substantial improvement of any
commercial, industrial or other nonresidential structure shall meet all of the
following requirements:
(1) In AE and Al-30 zones or other A zoned areas where the
base flood elevation has been determined or can be reasonably obtained, new
construction and substantial improvement of any commercial, industrial, or other
nonresidential structure shall have the lowest floor, including basement, elevated
one foot (1') or more above the base flood elevation, or elevated as required by
ASCE 24, whichever is greater. Mechanical equipment and utilities shall be
elevated at least one foot (1') above the base flood elevation, or
as required by ASCE 24, whichever is greater.
(2) If located in an AO zone, the structure shall meet the
requirements in Appendix A, attached to the ^"a-^,^e^ ^edified thk �e,.*;^^
Ordinance 5977, or superseding Ordinances.
(3) If located in an Unnumbered A zone for which a BFE is
not available and cannot be reasonably obtained, the structure shall be reasonably
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ORDINANCE NO. 6084
safe from flooding, but in all cases the lowest floor shall be at least two feet (2')
above the Highest Adjacent Grade.
(4) If buildings or manufactured homes are constructed or
substantially improved with fully enclosed areas below the lowest floor, the areas
shall be used solely for parking of vehicles, building access, or storage.
(5) Fully enclosed areas below the lowest floor that are
subject to flooding are prohibited, or shall be designed to automatically equalize
hydrostatic flood forces on exterior walls by allowing for the entry and exit of
floodwaters. Designs for meeting this requirement must either be certified by a
registered professional engineer or architect or must meet or exceed the following
minimum criteria:
(A) Have a minimum of two (2) openings with a total net
area of not less than one (1) square inch for every square foot of enclosed area
subject to flooding; and
(B) The bottom of all openings shall be no higher than
one foot (1') above grade; and
(C) Openings may be equipped with screens, louvers,
valves, or other coverings or devices provided that they permit the automatic
entry and exit of floodwater; and
(D) A garage attached to a residential structure,
constructed with the garage floor slab below the BFE, must be designed to allow
for the automatic entry and exit of floodwaters.
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ORDINANCE NO. 6084
Alternatively, a registered engineer or architect may design
and certify engineered openings.
(b) If the requirements of subsection G4diii(a) of this Section
are not met, then new construction and substantial improvement of any
commercial, industrial, or other nonresidential structure shall meet all of the
following requirements:
(1) Be dry flood proofed so that below one foot (1') or more
above the base flood level the structure is watertight with walls substantially
impermeable to the passage of water or dry flood proofed to the elevation
required by ASCE 24, whichever is greater; and
(2) Have structural components capable of resisting
hydrostatic and hydrodynamic loads and effects of buoyancy; and
(3) Be certified by a registered professional engineer or
architect that the design and methods of construction are in accordance with
accepted standards of practice for meeting provisions of this subsection based on
their development and/or review of the structural design, specifications and
plans. Such certifications shall be provided to the official as set forth in subsection
Ma of this Section; and
(4) Nonresidential structures that are elevated, not flood
proofed, must meet the same standards for space below the lowest floor as
described in subsection G4diii(a)(5) of this Section; and
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ORDINANCE NO. 6084
(c) Applicants who are flood proofing nonresidential buildings
shall be notified that flood insurance premiums will be based on rates that are one
foot (1') below the flood proofed level (e.g. a building flood proofed to the base
flood level will be rated as one foot (1') below).
iv. Recreational Vehicles: Recreational vehicles placed on sites
within Zones Al-30, AH, and AE on the community's
FIRM not including recreational vehicle storage lots shall either:
consecutive days;
(a) Be on the site for fewer than one hundred eighty (180)
(b) Be fully licensed and ready for highway use, on its wheels or
jacking system, attached to the site only by quick disconnect type utilities and
security devices, and have no permanently attached additions; or
(c) Meet the requirements of this subsection G and the
elevation and anchoring requirements for manufactured homes.
e. Additional Restrictions within Floodways: Floodways, defined in
RMC 4-11-060, are located within flood hazard areas established in subsection D
of this Section. Since the floodway is an extremely hazardous area due to the
velocity of flood waters which carry debris, potential projectiles, and erosion
potential, the following provisions apply:
i. Increase in Flood Levels Prohibited: Encroachments, including
fill, new construction, substantial improvements, and other development are
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prohibited unless certification by a registered professional engineer demonstrates
through hydrologic and hydraulic analyses performed in accordance with standard
engineering practice that:
(a) Encroachments shall not result in any increase in flood levels
during the occurrence of the base flood discharge; and
(b) There are no adverse impacts to the subject property or
abutting or adjacent properties; and
(c) There are no higher flood elevations upstream; and
(d) The impact due to floodway encroachment shall be analyzed
using future land use condition flows.
ii. Residential Construction in Floodways: Construction or
reconstruction of residential structures is prohibited within designated floodways,
except for:
(a) Repairs, reconstruction, or improvements to a structure
which do not increase the ground floor area; and
(b) Repairs, reconstruction or improvements to a structure, the
cost of which does not exceed fifty percent (50%) of the market value of the
structure either: (1) before the repair, reconstruction, or improvement is started;
or (2) if the structure has been damaged, and is being restored, before the damage
occurred. Work done on structures to comply with existing health, sanitary, or
safety codes or to structures identified as historic places may be excluded in the
fifty percent (50%).
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iii. Compliance Requirements: If this subsection G is satisfied, all
new construction and substantial improvements shall comply with all applicable
flood hazard areas reduction provisions of this Section.
iv. Bridges Crossing Floodways: In mapped or unmapped flood
hazard areas, future flow conditions shall be considered for proposed bridge
proposals crossing floodways.
v. Additional Provisions within AO Zones: Shallow flooding areas
appear on FIRMs as AO zones with depth designations. The base flood depths in
these zones range from one to three feet (1' to T) above ground where a clearly
defined channel does not exist, or where the path of flooding is unpredictable and
where velocity flow may be evident. Such flooding is usually characterized as sheet
flow. In addition to other provisions in this code, the following additional
provisions also apply in AO zones:
(a) New construction and substantial improvements of
residential structures and manufactured homes within AO zones shall have the
lowest floor (including basement and mechanical equipment) elevated above the
highest adjacent grade to the structure, one foot (1') or more above the depth
number specified in feet on the community's FIRM (at least two feet (2') above
the highest adjacent grade to the structure if no depth number is specified).
(b) New construction and substantial improvements of
nonresidential structures within AO zones shall either:
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ORDINANCE NO. 6084
(1) Have the lowest floor (ineludi^sbaseme„t) levated
above the highest adjacent grade of the building site, one foot (1') or more above
the depth number specified on the FIRM (at least two feet (2') if no depth number
is specified); or
(2) Together with attendant utility and sanitary facilities, be
above that level described in G41av(b)(1) of this
section so that any space below that level is watertight with walls substantially
impermeable to the passage of water and with structural components having the
capability of resisting hydrostatic and hydrodynamic loads and effects of
buoyancy. If this method is used, compliance shall be certified by a registered
professional engineer, or architect as described in subsection G4diii(b)(3) of this
Section.
(c) Require adequate drainage paths around structures on
slopes to guide floodwaters around and away from proposed structures.
(d) Recreational vehicles placed on sites within AO zones on the
community's FIRM either:
consecutive days, or
(1) Be on the site for fewer than one hundred eighty (180)
(2) Be fully licensed and ready for highway use, on its
wheels or jacking system, is attached to the site only by quick disconnect type
utilities and security devices, and has no permanently attached additions; or
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(3) Meet the requirements of subsections G4ev(a) and (b)
of this Section and the anchoring requirements for manufactured homes
(subsection G4dii of this Section).
vi. AE and Al-30 Zones with Base Flood Elevations but No
Floodways: In areas with BFEs (when a regulatory floodway has not been
designated), no new construction, substantial improvements, or other
development (including fill) shall be permitted within zones Al-30 and AE on the
community's FIRM, unless it is demonstrated that the cumulative effect of the
proposed development, when combined with all other existing and anticipated
development, will not increase the water surface elevation of the base flood more
than one foot (1') at any point within the community.
SECTION III. Upon approval of the City Attorney, the City Clerk is authorized to direct
the codifier to make necessary corrections to this ordinance, including the corrections of
scriveners or clerical errors; references to other local, state, or federal laws, codes, rules, or
regulations; or ordinance numbering and section/subsection numbering and references. The City
Clerk is further authorized to direct the codifier to update any chapter, section, or subsection
titles in the Renton Municipal Code affected by this ordinance.
SECTION IV. If any section, subsection, sentence, clause, phrase, or word of this
ordinance should be held to be invalid or unconstitutional by a court or competent jurisdiction,
such invalidity or unconstitutionality thereof shall not affect the constitutionality of any other
section, subsection, sentence, clause, phrase, or word of this ordinance.
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ORDINANCE NO. 6084
SECTION V. This ordinance shall be in full force and effect five (5) days after publication
of a summary of this ordinance in the City's official newspaper. The summary shall consist of this
ordinance's title.
PASSED BY THE CITY COUNCIL this 14th day of November, 2022.
APPROVED BY THE MAYOR this 14th day of November, 2022.
Approved as to form:
Shane Moloney, City Attorney .�0,<`k oFR'E,N,r0,y'�,,'
Date of Publication: 11/17/2022 (Summary) s SEAL
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ORD-CED:2243:D-220: 10/11/2022 o'',,,/j1111""`.,`'��w``
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