Ordinance No. 90-03-180 vCITY OF ATLANTIC BEACH, FLORIDA
ORDINANCE NO. 90-03-180
AN ORDINANCE OF THE CITY OF ATLANTIC BEACH, FLORIDA,
AMENDING CHAPTER 24, ZONING, SUBDIVISION AND LAND
DEVELOPMENT REGULATIONS, TO ESTABLISH STORMWATER ON-SITE
STORAGE REQUIREMENTS AND TREATMENT, FLOODPLAIN STORAGE,
AND NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NDPES) REQUIREMENTS, AND PROVIDING AN EFFECTIVE DATE
BE IT ENACTED BY THE CITY COMMISSION ON BEHALF OF THE PEOPLE OF
THE CITY OF ATLANTIC BEACH, FLORIDA:
Section 24-67. Development review and issuances of development permits; revise (d)
Stormwater drainage requirements, to read:
(d) Stormwater drainage, storage and treatment requirements.
1. Topogr,_aphy and Grading: All lots and development sites shall be constructed and
graded in such a manner so that the Stormwater drains to the. adjacent street, an existing natural
element used to convey Stormwater (See section 22-303, definitions: Stormwater management
system), or a city drainage structure after meeting on-site storage requirements, as listed in this
Section. The city shall be provided with apre-construction topographical survey prior to the
issuance of a development permit and apost-construction topographical survey prior to the
issuance of a certificate of occupancy. The surveys shall be prepared by a licensed Florida
surveyor, and the requirement for either or both surveys may be waived by the Director of Public
Works if they aze determined to be unnecessary.
2. On-Site Storage: The applicant will be required to provide on-site storage, such that
there is no increase in the rate or volume of flow to off-site, from every developed or
redeveloped parcel, and provide documentations and calculations to demonstrate compliance.
Subdivisions and developments previousl}! .permitted by the St. Johns River Water M ement
District (SJRWNID2, and have an in compliance retention/detention system that collects and
controls run-off, aze exempt. The requirement for on-site storage may be waived by the Director
of Public Works if storage is determined to be unnecessazv or unattainable.
Volume calculations for lots that require on-site storage should be based on the difference
in run-off volume generated by the new impervious azea ("delta volume") and would be
calculated bv:
V=CAR/12, where
V =volume of storage in cubic feet,
A = area of the lot in square feet,
R = 25 year and 24 hour rainfall depth (9 3 inches) over the lot azea, and
C =run offcoefficient, which is 0.6 for the 50% maximum imperviousness 0 4 for 25%
imperviousness, and 0.2 for 0% imperviousness.
This delta volume (post V minus pre V in cubic feed must be stored at least 1 foot above
the wet season water table and below the overflow point to off-site (in many cases this may be
the adjacent road elevation. As an option. and as approved by the Director of Public Works, the
owner of the pazcel to be developed or redeveloped may implement, at the applicant's cost, off-
site storage and necessar~onveyance to control existing flood stages off-site.
3. Flood Plain Storage: There shall be no net loss of storage for azeas in the 100-yeaz
flood lain, where a floodplain elevation has been defined by either the Federal Emer enc
Management Agency fFEMAZ on Flood Insurance Rate Map~FIRMs), the 1995 Stormwater
Master Plan, the Core City project, or the 2002 Stormwater Master Plan Update e.g., Hopkins
Creek). Site rg ading shall create storage on site to mitigate for filling of volume on-site. This
storage is in addition to the storage required for the increase in impervious azea.
4. Stormwater Treatment: Stormwater treatment shall be provided for a volume
equivalent to either retention or detention with filtration, of the run-off from the first one (1 inch
of rainfall: or as an option, for facilities with a drainage azea of less than one hundred (100)
acres, the first one-half ('/~) inch ofrun-offpursuant to Chanter 62-25. Florida Administrative
Code FAC). No discharge from any stormwater facility shall cause or contribute to a violation
of water quality standazds as provided in Section 62.302 of the Florida Administrative Code.
This treatment volume can be included as part of the on-site storage requirement in item d (2Lf
this Section.
5. NPDES Requirements: All construction activities shall be in conformance with the
City's National Pollutant Dischazge Elimination Systems (NPDES) ,permit, in addition to the
requirements of the Water Management District and the Florida Department of Environmental
Protection. NPDES requirements include use of Best Management Practices (BMPs,Zprior to
discharge into natural or artificial drainage systems. Beginning Mav 1 2003 all construction
projects of one acre or more will require a NPDES permit.
6. Enforcement: Subsequent to approval of a propertyowner's final_grading, including
on site and/or flood plain storage and stormwater treatment. the improvements shall be
maintained by the property owner. Failure to maintain the improvements will require restoration
upon notification by the Director of Public Works within a stipulated timeframe If restoration
is not timely completed. the City shall have the right to complete the restoration and the City's
actual costs incurred. together with a chazge of 100% of said costs to cover the Cites -
administrative expenses. shall be chazged to the owner.
This ordinance shall take effect immediately upon its final passage and adoption.
Passed by the City Commission on first reading this /D ~ day of ~ (h, Gov , 2003.
Passed by the City Commission on the second and final reading this ~ day of
G~, , 2003.
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