HomeMy WebLinkAbout2005-12-706472888
ORDINANCE NO.2005-12-7064
AN ORDINANCE AMENDING SECTION 50-151
THROUGH SECTION 50-157 OF THE CODE OF
ORDINANCES OF THE CITY OF PADUCAH
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BE IT ORDAINED BY THE CITY OF PADUCAH, KENTUCKY:
SECTION 1. That Article III, Stormwater Conveyance and Management,
of Chapter 50, Floods, of the Code of Ordinances of the City of Paducah, Kentucky, is
hereby amended to read as follows:
"ARTICLE III. STORMWATER CONVEYANCE AND MANAGEMENT
Sec. 50-151. Purpose and scope of article.
Stormwater management is vital in promoting the health, safety and general welfare of
the public. It is the intent of this article, in an effort to minimize the dangers of flooding
to life and property and to protect local water quality and maintain the integrity of stream
channels, that certain runoff control devices be provided as land areas are developed or
redeveloped. The design criteria for stormwater conveyance structures are outlined in this
article."
"Sec. 50-152. Definitions.
For the purpose of this article, the following definitions shall apply unless the context
clearly indicates or requires a different meaning.
City plan review staff. The City Engineer and/or other designated officials.
Controlled release structure. A facility constructed to regulate the volume of stormwater
runoff that is conveyed during a specific length of time.
Conveyance structures. Water -carrying devices or improvements such as channels,
ditches, storm sewers, culverts, inlets, and the like.
Detention or retention. Restraining the rate of stormwater runoff with some natural or
manmade devices.
Developed. Conditions after construction or other manmade change to improved or
unimproved land, including, but not limited to, buildings or other structures, mining,
dredging, filling, grading, paving, excavation, or drilling operations.
Excess stormwater. The calculated runoff produced under a natural or pre -developed
condition versus the calculated runoff produced under an altered or post -developed
condition, or that portion of stormwater runoff which exceeds the capacity of the storm
sewers or natural drainage channels serving a specific watershed.
Impervious surface. Asphalt, concrete or any other surface which does not allow
measurable infiltration.
Lamer common plan of development or sale means a contiguous area where multiple
separate and distinct construction activities are planned to occur at different times on
different schedules under one plan, e,e_ a housing development of five V4 acre lots.
Natural drainage. Water which flows by gravity in channels formed by the surface
topography of the earth prior to changes made by the efforts of humans.
Off-site. External to the boundary of a development.
On-site. Internal to the boundary of a development.
Point discharge. Release of stormwater at a specific location.
Runoff. Rainfall excess after natural losses from infiltration, evaporation, transportation
or incidental poundage.
i
Stormwater runoff release rate. The rate at which stormwater runoff is released from
dominant to servient land.
Stormwater storage area. An area designed to temporarily accumulate excess
stormwater.
Swale. Surface -type conveyance for stormwater, usually designated to carry incidental,
localized runoff."
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603
"Sec. 50-153. Stormwater conveyance and management facilities required.
The requirements in this ordinance shall apply to:
(a) all land disturbing activities and all development or re -development activities that
disturb an area greater than or equal to one (1) acre.
(b) sites that are smaller than one (l.) acre may also be covered by these regulations if
they are a part of a larger common plan of development or sale.
c) any nonresidential development for which the area paved and under roof is equal
to or greater than 10,000 square feet.
These regulations shall apply to land disturbing activities in the area designated by the
Kentucky Division of Water for coverage under the KPDES SMS4 Permit.
Unless included in exemotions listed in section 50-155 or a waiver granted, all
development occurring within the city and subject to this ordinance shall provide for
properly sized stormwater conveyance facilities and shall contain on-site, or provide off-
site, stormwater management facilities capable of controlling increased runoff relative to
equal to but not greater than its predeveloped condition.
listed in seefien 50 ,
be approved tinjess it ifieludes either a plan a
resultingerosion and sediment ffem the development will be eentr-01.1ed or- managed 0
, unless exempt,
ne building pesha4l be issued for an), pai�eel of lot until eithef an adequate ster-fnwatef management plan
addfosging ,
sediment and steRawater, or- a doeumented request 44
thereof, has been appr-ave4,
The use of other methods of controlling, peak discharge rates and pollutant removal, such
as bio -retention swales, infiltration ditches, hydrodynamic separators, and created
wetlands may be required by the City, in its sole discretion, for some large developments.
Additionally, the City will. promote conservation .measures such as buffer strips and
greenways as acceptable techniques toward the protection and improvement of local
waterways."
"Sec. 50-154. Stormwater conveyance facilities design criteria.
The following criteria shall control when designing stormwater conveyance facilities:
(1) Open channels and roadside ditches. The design storm for the design of open
channels and roadside ditches shall be a storm with a recurrence frequency of ten
years. The time of concentration for open channel and roadside ditch design
should be assumed to be 20 minutes.
(2) Storm sewers and inlets. The design storm for the design of storm sewers and
inlets shall be the five-year storm. Storm sewers and inlets shall be checked under
ten-year storm loading conditions for ponding limits. The ponding limit for streets
with curb and gutter shall be an eight -foot spread measured from gutter to driving
lane. Spread calculations shall be based upon an intensity of four inches per hour.
Pipes should be sized based upon the actual time of concentration. The minimum
time of concentration should be assumed to be eight minutes.
(3) Entrance pipes and cross drains. The design storm for the design of entrance
pipes and cross drains shall be the ten-year storm. The duration of the design
storm shall be assumed to be equal to the calculated time of concentration. The
minimum time of concentration shall be assumed to be eight minutes. Entrance
pipes and cross drains shall be checked under 25 -year storm conditions to ensure
against overtopping of roadways and flood damage to affected areas. Situations
requiring pipes larger than 36 inches shall be designed using the culvert criteria in j
subsection (4) of this section.
(4) Culverts. The design storm for the calculation of runoff for culvert design shall
be the 25 -year storm. The duration of the design storm shall be assumed to be
equal to the calculated time of concentration. The recommended check storm is
the 100 -year storm. The maximum headwater under 100 -year storm conditions
should not be allowed to overtop roads or increase the flooding potential in the
affected areas.
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(5) Erosion control. Plans for stormwater conveyance systems shall include
appfepn.ately designed... . ...
to both epen an
b
elesed eenduits within. the system.. (Best Management Pr-aetioes for- Genstmetien
P-r-oteetion Cabinet should be used as a design manual for- er-esion and sedifnent
sones the applicable provisions identified under Article IV, Erosion Prevention
and Sediment Control, of this chapter.
(6) Design certification. Design of all stormwater conveyance facilities shall be
prepared and stamped by a licensed professional engineer (Kentucky registration
required). Design methods shall be in accordance with the Kentucky Department
of Highways' Manual of Instructions for Drainage Design, latest edition."
"Sec. 50-155. Stormwater management facilities design criteria.
As a minimum, the following criteria shall be followed when designing a stormwater
management facility:
(1) Design storm. Stormwater management facilities shall be designed to retain the
difference in the pre -development and post -development ten-year, 24-hour storm
event.
(2) Emergency spillways. Emergency spillways shall be designed to pass the 100 -
year storm. The effect of the 100 -year storm must be considered and documented
in the design of all stormwater management facilities.
(3) Design calculations. Design calculations submitted must include, but are not
limited to, the following:
a. Contributing drainage area, in acres. Indicate if pre -development and post -
development areas differ.
b. A breakdown of surface type for pre -development and post -development
conditions (such as grassed, paved, roofed, and the like).
C. Stage -storage curve for the proposed stormwater management facility.
d. Stage -discharge curve for the outlet structure of the proposed stormwater
management facility.
e. Inflow and outflow hydrographs for pre -development and post -
development conditions.
f. Emergency spillway design calculations.
g. Embankment design criteria as it relates to slope stability and compaction
requirements during construction.
4) Gradiant. All detention basins having a vegetative_ cover shall be designed
constructed and maintained equal to or greater than one percent 0%) throughout
to the point of discharge.
(43L_5� Stormwater Management Plan. The final stormwater management plan for the
entire development shall include, but not be limited to, the following:
a. All calculations, assumptions and criteria used in the design of the
stormwater management facility.
b. All plans and profiles of proposed storm sewers and open channels
including horizontal and vertical controls, elevations, sizes, slopes and
materials.
C. Location, dimensions and design details required for the construction of all
facilities.
d. A description of the operation and maintenance needs for the stormwater
management facilities.
e. All information relative to the design and operation of emergency
spillways.
f. Project specifications relative to erosion and sedimentation control. (1}
guidelinesdesign asseeiated with efesion and sediment.
g. All deed restrictions, easements and rights-of-way.
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h. The ownership and maintenance responsibilities for all stormwater
management control structures during and after development. The identity
of the responsible individual, corporation, association or other specific
entity and the specific maintenance must be outlined on the plan.
{}( Exemptions. Exemptions from the stormwater management requirements
contained herein shall be granted to the following:
a. ,
five units or Faefe. Land disturbing activities on property used for
agricultural, horticultural or botanical production of plants and animals
useful to man, including but not limited to: forages and sod crops,rgrains
and feed crops, tobacco, cotton and peanuts; dairy animals and dairy
products; poultry and poultry products-, livestock, including beef cattle
sheep, swine, horses, ponies, mules or goats, including the breeding and
grazi.ng of these animals; bees; fur animals and aquaculture, except that the
construction of a structure used for agricultural purposes of one or more
acres, such as broiler houses, machine sheds, repair shops and other major
buildings and which require the issuance of a building permit shall require
the submittal and approval of a storm water management plan prior to the
start of the land disturbing activity.
b. Residential subdivisions of fesideRtial planned unit developfaentswhef.e
Fniriffl"1-jell sizeis gfeater- than twe aeres. Land disturbing activities
undertaken on forestland for the production and harvesting of timber and
timber products.
C. Minor land disturbing activities such as residential. gardens, individual
residential or commercial landscaping, minor home repairs, or
maintenance work and construction or maintenance of individual
underground utility connections.
d. Activities undertaken by local governments or special purpose or public
service districts relating to the emergency repair and maintenance of
existing facilities and structures. These activities will be carried out using
appropriate best management practices to minimize the impact on the
environment and surrounding properties.
ele. Any nonresidential development for which the area paved and under roof
is less than 10,000 square feet.
4,-. f. Waivers may also be granted if, in other cases, the developer can provide
sufficient documentation that the proposed development will not result in
an adverse impact either upstream or downstream of the proposed site.
Waivers shall be granted solely at the discretion of the eity pl,anFe{
4 City Engineer, based upon interpretation of the documentation
presented by the developer in conjunction with 4.a# his or her knowledge
of the relationship of the proposed development to the adjacent property.
(64M Design certification. Design of all stormwater management and conveyance
facilities shall be prepared and stamped by a licensed professional engineer
(Kentucky registration required).
k74L8Construction certification. Prior to final approval of the development, the
licensed professional engineer must submit certification that the stormwater
management and conveyance facilities were constructed in accordance with the
approved plan. Final approval shall also provide evidence of the recording of all
stormwater conveyance and management facilities deed restrictions, easements
and rights-of-way. Any request for deviation from the approved plan during
construction shall be submitted to the City Engineer in
writing for approval.
(-8)L9j Ownership, operation and maintenance of stormwater control
�tcilities. For all developments requiring= stol-mwater control facilities, ownership
and maintenance responsibilities remain with the property owner/developer.
ewte kff
single.ly Yfesidential subdiyisiens, the eity..
ay a0eept Ownership
Lli1,J 111LL1.1 [LVl[LL314V ,
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"Sec. 50-156. Issuance of certificate of occupancy.
No certificate of occupancy shall be issued for any development which is subject to the
regulations of this article unless and until all requirements and criteria of this article are
p fully complied with.
Sec. 50-157. Penalty.
Any person who is su
firm,
corporation or agency acting as principal, agent, employee or otherwise, who fails to
comply with the provisions of this Ordinance shall be guilty of a. misdemeanor and upon
conviction thereof shall be punishable by a fine of not less than one hundred dollars
($1.00.00)/d.ay and not more than five hundred dollars ($500.00)/day, or by imprisonment
for not more than ninety (90) days, or both, for each separate offense. Each day there is a
violation of any art of this Ordinance shall constitute a separate offense.
SECTION 2. This ordinance shall be read on two separate days and will
become effective upon summary publication
C\) ATTEST:
Tammara S. Brock, City Clerk
Introduced by the Board of Commissioners, December 13, 2005
Adopted by the Board of Commissioners, December 20, 2005
Recorded by Tammara S. Brock, City Clerk, December 20, 2005
Published by The Paducah Sun, December 28, 2005
\ord\eng\50-151-50-157
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