HomeMy WebLinkAbout22-002 ORDINANCE No. 2022-2
FILE NO.: TLDC-8202126114
AN ORDINANCE OF THE BOARD OF COUNTY COMMISSIONERS OF ST. A c
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LUCIE COUNTY, FLORIDA, AMENDING THE TEXT OF THE LAND °�°o p
DEVELOPMENT CODE, CHAPTER VII, DEVELOPMENT DESIGN AND z cr
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IMPROVEMENT STANDARDS, SECTION 7.04.01.D.3. — AREA, YARD, m m o o
HEIGHT, AND OPEN SPACE REQUIREMENT, FILLED LANDS; TO o 8 F,m
ESTABLISH REQUIREMENTS FOR A STORMWATER GRADING PLAN FOR `0
SINGLE-FAMILY AND DUPLEX INFILL DEVELOPMENT THAT DOES NOT m
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HAVE AN APPROVED MASTER DRAINAGE PERMIT FROM THE WATER o o
MANAGEMENT DISTRICT; PROVIDING DEFINITIONS; PROVIDING SIMPLE g> m
DESIGN STANDARDS; PROVIDING FOR PERPETUAL MAINTENANCE OF 0
THE STORMWATER CONVEYANCE SYSTEM; PROVIDING COMPLIANCE o
BEFORE THE ISSUANCE OF A CERTIFICATE OF OCCUPANCY; PROVIDING o
FOR CONFLICTING PROVISIONS; PROVIDING FOR SEVERABILITY; Z 0
PROVIDING FOR APPLICABILITY; PROVIDING FOR FILING WITH THE
DEPARTMENT OF STATE; PROVIDING AN EFFECTIVE DATE; PROVIDING
FOR ADOPTION AND CODIFICATION
WHEREAS, the Board of County Commissioners of St. Lucie County, Florida, (Board)
recognizes that land development permanently alters how stormwater flows across a
site due to grading, compaction, and the installation of impervious materials; and
impervious areas increase the amount of rainwater runoff and may cause flooding; and
WHEREAS, new infill single-family and duplex development shall be responsible to
protect adjacent properties from adverse impacts due to uncontrolled runoff and make
sure there is an adequate stormwater conveyance system so that adjacent neighbors
will not be adversely affected; and,
WHEREAS, the St. Lucie County Land Development Code currently requires all
permittees to execute a Filled Lands Affidavit assuring adequate drainage so that the
immediate community will not be adversely affected; and
WHEREAS, the St. Lucie County Land Development Code does not currently provide
stormwater design standards for single-family and duplex infill development; and
WHEREAS, many communities along the Treasure Coast have stormwater standards
for single-family and duplex infill development to minimize runoff to adjacent properties;
and
Page 1 of 8
ORDINANCE No. 2022-2
FILE NO: TLDC-8202126114
AN ORDINANCE OF THE BOARD OF COUNTY COMMISSIONERS OF ST.
LUCIE COUNTY, FLORIDA, AMENDING THE TEXT OF THE LAND
DEVELOPMENT CODE, CHAPTER VII, DEVELOPMENT DESIGN AND
IMPROVEMENT STANDARDS, SECTION 7.04.01.D.3. — AREA, YARD,
HEIGHT, AND OPEN SPACE REQUIREMENT, FILLED LANDS; TO
ESTABLISH REQUIREMENTS FOR A STORMWATER GRADING PLAN FOR
SINGLE-FAMILY AND DUPLEX INFILL DEVELOPMENT THAT DOES NOT
HAVE AN APPROVED MASTER DRAINAGE PERMIT FROM THE WATER
MANAGEMENT DISTRICT; PROVIDING DEFINITIONS; PROVIDING SIMPLE
DESIGN STANDARDS; PROVIDING FOR PERPETUAL MAINTENANCE OF
THE STORMWATER CONVEYANCE SYSTEM; PROVIDING COMPLIANCE
BEFORE THE ISSUANCE OF A CERTIFICATE OF OCCUPANCY; PROVIDING
FOR CONFLICTING PROVISIONS; PROVIDING FOR SEVERABILITY;
PROVIDING FOR APPLICABILITY; PROVIDING FOR FILING WITH THE
DEPARTMENT OF STATE; PROVIDING AN EFFECTIVE DATE; PROVIDING
FOR ADOPTION AND CODIFICATION
WHEREAS, the Board of County Commissioners of St. Lucie County, Florida, (Board)
recognizes that land development permanently alters how stormwater flows across a
site due to grading, compaction, and the installation of impervious materials; and
impervious areas increase the amount of rainwater runoff and may cause flooding; and
WHEREAS, new infill single-family and duplex development shall be responsible to
protect adjacent properties from adverse impacts due to uncontrolled runoff and make
sure there is an adequate stormwater conveyance system so that adjacent neighbors
will not be adversely affected; and,
WHEREAS, the St. Lucie County Land Development Code currently requires all
permittees to execute a Filled Lands Affidavit assuring adequate drainage so that the
immediate community will not be adversely affected, and
WHEREAS, the St. Lucie County Land Development Code does not currently provide
stormwater design standards for single-family and duplex infill development; and
WHEREAS, many communities along the Treasure Coast have stormwater standards
for single-family and duplex infill development to minimize runoff to adjacent properties;
and
Page 1 of 8
WHEREAS, the County acknowledges these regulations will not solve all stormwater-
related issues; however, this is a reasonable effort to reduce the impacts of stormwater
runoff from single-family and duplex infill development on adjacent properties; and
WHEREAS,the Board of County Commissioners desires to implement a simple method
to calculate the swale flow area, including standards for a stormwater lot grading plan
for infill single-family and duplex development, subject to the terms and conditions of
this Ordinance.
WHEREAS, on October 21, 2021, the Local Planning Agency/Planning and Zoning
Commission held a public hearing on the proposed Ordinance after publishing due
notice in the St. Lucie News Tribune and recommended the proposed Ordinance be
forwarded with a recommendation for approval.
WHEREAS, on January 11, 2022, this Board held the first public hearing on the
proposed Ordinance after publishing due notice in the St. Lucie News Tribune.
WHEREAS, on February 1, 2022, this Board held its second public hearing on the
proposed Ordinance, after publishing due notice in the St. Lucie News Tribune.
WHEREAS, the proposed amendment to the St. Lucie County Land Development Code
is consistent with the general purpose, goals, objectives, and standards of the St. Lucie
County Comprehensive Plan, are internally consistent with the remainder of the Land
Development Code, and are in the best interest of the health, safety, and public welfare
of the citizens of St. Lucie County, Florida.
NOW, THEREFORE, BE IT ORDAINED by the Board of County Commissioners of St.
Lucie County, Florida:
PART A. INCORPORATION OF RECITALS. The above recitals are incorporated
herein by reference and form an integral part of the Ordinance.
PART B. SHORT TITLE. This Ordinance shall be known and referred to as the Infill
Development Stormwater Plan.
PART C. INTENT AND PURPOSE. The intent and purpose of this Ordinance is to
create simple design standards for infill single-family and duplex development.
Page 2 of 8
PART D. CHAPTER 7.04.01.D.3. —AREA, YARD, HEIGHT, AND OPEN SPACE
REQUIREMENT, FILLED LANDS.
7.04.01.D.3. — Filled Lands.
Where fill is used, the owners of the property on which the fill is being located shall be
responsible for assuring adequate drainage so that the immediate community will not be
adversely affected. All permittees are required to execute a Filled Lands Affidavit with an
application for a building permit. The Affidavit shall include an acknowledgment to retain
an engineer or other design professional if the stormwater grading plan fails and that the
applicant agrees to hold St. Lucie County harmless for any future drainage rework that
may be required as a result.
A. Requirements for Stormwater Grading Plan for Single-Family and Duplex Infill
Development
This section uses simple design standards to avoid the necessity of complex engineering
calculations and analysis. The applicant may, however, choose to retain the services of
an engineer at their expense.
1. Purpose
This section provides stormwater runoff standards for infill residential development
within the unincorporated County to protect existing structures from adverse impacts
of uncontrolled runoff from infill construction.
2. Definitions
Bio-swale means a storm water runoff conveyance system that can absorb low
flows or carry runoff from heavy rains to storm sewer inlets or directly to surface
waters; and, for the purposes of this Code, it is a long, channeled depression or trench
that receives rainwater runoff(from the roof of the residence) and has vegetation (such
as grasses, flowering herbs, and shrubs) and organic matter (such as mulch) to slow
water infiltration and filter out pollutants.
Cistern, rainwater, means a waterproof reservoir for catching rainwater; it may be
connected to a roof gutter system and downspouts that directs the rainwater to the
storage cistern; and it may be located above ground or underground, and built of
various materials.
Elevated building means a non-basement building which has its lowest elevated floor
raised above ground level by foundation walls, shear walls, post, piers, pilings; or
columns.
Fill means a volume of earthen material that is placed and compacted for the purpose
of filling in a hole or depression to create a structure that, when placed, changes the
grade or elevation of the receiving site.
Page 3 of 8
lnfill Lot Development means developing parcels within areas without a master
drainage plan.
Lot means a tract, plot, or portion of land intended as a unit for immediate or future
use, transfer of ownership, or building development.
Grading Plan means a plan that delineates the shaping and grading of the land to
direct surface runoff away from the structure and towards a swale or other stormwater
conveyance system.
Rain garden, means a shallow dug-out area that is landscaped with native
plants and designed to collect stormwater runoff that comes from nearby
impermeable surfaces, such as roofs, driveways, and sidewalks.
Slope means a surface that rises at an angle; slope is the measure of the steepness
of a line.
Storm water means any surface flow, runoff, and drainage consisting entirely of water
from any form of natural precipitation and resulting from such rain.
Swale means a valley-like section of two slopes on a piece of land or a low place on a
piece of land that is often wet with stormwater
3. Applicability; Exemption; Waiver
The provisions of this section shall only apply to development within the unincorporated
county boundaries for lots being developed that do not have an approved stormwater
management plan. Any development subject to this section must be designed to minimize
directed runoff to an adjacent property. Additions or accessory structures less than 300
square feet have a one-time exemption from this section. The property owners of
substantial acreage may demonstrate there is no need for a stormwater management
plan; in that event, the Department Director may waive the requirement for a stormwater
management plan.
4. Requirements.
All applicants that propose to develop a single family home or duplex on infill property
shall:
a. Submit a topographic survey that identifies existing conditions within and
adjacent to the lot, including the finish floor elevation of any adjacent
structures. The survey shall include a minimum of four (4) elevations
along each property line to include the corners of the lot. The survey
shall have been completed within six (6) months of building permit
submittal.
Page 4 of 8
b. Submit a stormwater grading plan specifying the elevations as noted in
'a' above, and include lot type, swale locations, spot elevations, flow
direction arrows, side slope of 4 to 1, north directional arrow and scale,
floor area calculation, a yard basin if applicable, retaining wall details if
applicable.
c. Limit the amount of fill on the lot; the amount of fill shall be the minimum
necessary for the construction of the building.
d. Note foundation construction methods.
1. The foundation grade, fill, shall be limited to 18" not to exceed 36"
for an elevated building (a building on piles, stilts, stem wall, etc.)
a. If an applicant wants to build the foundation grade with fill
greater than 36 inches, a stormwater management plan
designed by an engineer is required; and, the design must
include additional stormwater retention above this Code section
to be approved by the Planning & Development Services
Director.
2. Alternative methods of construction that are not listed above in d.1
may be considered, however, a report from an engineer is required
to demonstrate compliance with this code.
e. Limit the finished floor elevation of the ground floor to be no more
than three (3) feet above the crown of the road unless required by the
Florida Building Code or the State of Florida Health Department; or
other constraint shall require a stormwater grading plan and report by
a professional engineer to be approved by the Planning &
Development Services Director.
1. Pumps for on-site sewage disposal systems (septic tank and
drain fields) may be required if a gravity drain field causes the
finished floor elevation to be higher than specified in 4 (e).
f. Limit the maximum slope of fill on a lot so that the slope does not
exceed 4:1.
g. Include roof drainage provisions such as gutters and splash
pads/downspouts, so that the runoff is directed away from the adjacent
lot toward the stormwater conveyance system.
h. Construct a swale along the back property line of the lot with a high
point in the middle of the swale along the rear lot line. The swale shall
slope from the high point to the side lot lines on both sides and continue
Page 5 of 8
to the front property line roadside swale or other approved outfall.
Swales shall be no greater than 2 feet in width unless otherwise
approved. See Section 5 Swale Flow Area Ratio Value Table. If an
alternate method of design is proposed, the applicant has the option to
provide an engineered plan.
1. When conditions are extreme, and there is a need for an
additional type of conveyance system, the applicant may
consider retaining walls, berms, piping, or yard drains to aid in
directing runoff to the conveyance system. A retaining wall
design, berm, use of an existing canal system or a piping plan
on site shall require a plan prepared by an engineer. The use of
a canal system may require permits for regulatory agency. The
outfall piped conveyance system shall be required to be
maintained.
Sod all swales to prevent erosion, unless used as a rain garden.
L Convey off-site runoff that flows to or through the lot to the adjacent
roadside or other approved outfall. New construction shall not block
this flow.
k. Encourage alternative stormwater designs, (such as cisterns, bio-swales and
rain gardens) to prevent runoff to adjacent property.
5. Swale Flow Area - Any applicant may use the method of determining adequate flow
area using the below Table:
Step 1. Determine water flow patterns on the project site and outfall (where
the flow exits the property).
Step 2. Determine water flow area size by calculating the width and length of
the affected site.
Step 3. Using the Table below, determine the swale flow area by finding the
impervious area of building footprint in the first column and identifying the
column of water flow area size from step 2 above.
Step 4. Using the Table below, if the value is between the rows and columns,
chose the swale flow area ratio value of the next row and column in the Table.
Step 5. The following equation shall be used to calculate the dimensions of
the swale flow area:
Swale Depth = (Swale Flow Area Ratio from Steps 3 or 4) x 2.0 x (width of swale = 1.0)
Page 6 of 8
Swale Flow Area Ratio Value Table
Proposed Water Flow Area Size(from step 2.In Square Feet)
Impervious Area
+in sq.ft. 1000 5000 10,890 15,000 21,780 30,000 40,000
1200 0.12 0.19 0.29 0.36 0.48 0.62 0.80
2500 0.23 0.30 0.40 0.47 0.59 0.73 0.91
3000 0.27 0.34 0.44 0.51 0.63 0.78 0.95
4000 0.35 0.42 0.53 0.60 0.72 0.86 1.03
5000 0.44 0.51 0.61 0.68 0.80 0.94 1.12
7500 0.65 0.72 0.82 0.89 1.01 1.15 1.33
6. Maintenance
Perpetual maintenance of the stormwater conveyance system, including alternative
conveyance systems, shall be the responsibility of the owner of the improved property.
The maintenance shall include the routine mowing any growth of grass, weeds, flora,
or underbrush within the swale area to a height of eight inches or less; removing trash,
debris, or litter; and removing any obstructions that impede stormwater drainage.
7. Compliance
A final stormwater inspection shall be performed for compliance with the approved
stormwater grading plan prior to the issuance of a Certificate of Occupancy.
PART E. CONFLICTING PROVISIONS.
Special acts of the Florida legislature applicable only to unincorporated areas of St. Lucie
County, County ordinances and County resolutions, or parts thereof, in conflict with this
Ordinance are hereby superseded by this Ordinance to the extent of such conflict.
PART F. SEVERABILITY.
If any portion of this Ordinance is for any reason held or declared to be unconstitutional,
inoperative, or void, such holding shall not affect the remaining portions of this Ordinance. If this
Ordinance or any provision thereof shall be held to be inapplicable to any person, property, or
circumstance, such holding shall not affect its applicability to any other person, property, or
circumstance.
PART G. APPLICABILITY OF ORDINANCE.
This Ordinance shall be applicable in the unincorporated area of St. Lucie County.
PART H. FILING WITH THE DEPARTMENT OF STATE.
Page 7 of 8
The Clerk is hereby directed forthwith to send a certified copy of this Ordinance to the Bureau
of Administrative Code and Laws, Department of State, The Capitol, Tallahassee, Florida
32304.
PART I. EFFECTIVE DATE.
This Ordinance shall take effect upon filing with the Department of State.
PART J. ADOPTION.
After motion and second, the vote on this Ordinance was as follows:
Sean Mitchell, Chair AYE
Frannie Hutchinson, Vice-Chair AYE
Linda Bartz, Commissioner AYE
Chris Dzadovsky, Commissioner AYE
Cathy Townsend, Commissioner AYE
PART K. CODIFICATION.
Provisions of this Ordinance shall be incorporated in the St. Lucie County Code and Compiled
Laws, and the word "ordinance" may be changed to "section", "article", or other appropriate
word, and the sections of this Ordinance may be renumbered or re-lettered to accomplish such
intention; provided, however, that Parts B through H shall not be codified.
PASSED AND DULY ENACTED this first day of February, 2022.
Attest: Board of County Commissioners St. Lucie County, Florida
044
, ',A/ o By:
Deputy Clerk • m Chair
* Approved • to Form an•
co,-"Nri Ft.0091' Correctness:
By: IL/A//_
Co ty Attor -
Page 8 of 8
RON DESANTIS LAUREL M. LEE
Governor Secretary of State
February 15, 2022
Ms. Michelle R. Miller
Clerk & Comptroller
St. Lucie County
2300 Virginia Avenue
Fort Pierce, Florida 34982
Attn: Vera Smith
Dear Ms. Miller:
Pursuant to the provisions of Section 125.66, Florida Statutes, this will acknowledge receipt of your
electronic copy of St. Lucie County Ordinance No. 2022-2, which was filed in this office on February 15,
2022.
Sincerely,
Anya Owens
Program Administrator
AO/lb
R. A. Gray Building 500 South Bronough Street Tallahassee, Florida 32399-0250
Telephone: (850) 245-6270
RON DESANTIS LAUREL M. LEE
Governor Secretary of State
February 15, 2022
Ms. Michelle R. Miller
Clerk & Comptroller
St. Lucie County
2300 Virginia Avenue
Fort Pierce, Florida 34982
Attn: Vera Smith
Dear Ms. Miller:
Pursuant to the provisions of Section 125.66, Florida Statutes, this will acknowledge receipt of your
electronic copy of St. Lucie County Ordinance No. 2022-2, which was filed in this office on February 15,
2022.
Sincerely,
Anya Owens
Program Administrator
AO/lb
R. A. Gray Building 500 South Bronough Street Tallahassee, Florida 32399-0250
Telephone: (850) 245-6270