HomeMy WebLinkAbout2021-03-8676149900
ORDINANCE NO. 2021-03-8676
AN ORDINANCE AMENDING CHAPTER 50,
ARTICLE III. "STORMWATER
CONVEYANCE AND MANAGEMENT" OF
THE CODE OF ORDINANCES OF THE CITY
OF PADUCAH, KENTUCKY
WHEREAS, this Ordinance amends Chapter 50, Article III "Stormwater Conveyance and
Management," of the Code of Ordinances of the City of Paducah, Kentucky; and
WHEREAS, this Ordinance is being enacted pursuant to mandates imposed by the
Federal Clean Water Act (33 U.S.C. § 1251 et seq. as may be amended) ("CWA"), the National
Pollution Discharge Elimination System (33 U.S.C. §1342 as may be amended) ("NPDES"), and
the Kentucky Pollutant Discharge Elimination System (401 KAR 5:050 to 401 KAR 5:080 as
may be amended) in particular those parts that require local governments to comply with water
pollution control requirements.
NOW THEREFORE be it ordained by the City Commission of the City of Paducah as
follows:
SECTION 1. That Chapter 50, Article III. "Stormwater Conveyance and Management," is
hereby amended and restated to read as follows:
ARTICLE III. STORMWATER CONVEYANCE, MANAGEMENT, AND QUALITY
Sec. 50-151. Purpose and scope of article.
Proper stormwater management and good water quality are 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 controls be provided as land areas are developed or
redeveloped. The design criteria for stormwater conveyance and water quality control facilities 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.
80th Percentile Rainfall Event. The rainfall event, based on historical rainfall records, that
represents an event that is equal to or greater than 80 percent of the rainfall events that would be
expected to occur in a typical year. Based on an analysisprecipitation records from 1971 to
2011, it has been determined that for the City of Paducah, this event produces a surface depth
runoff of 0.7 inches.
Best Management Practices or BMPs. Schedules of activities, prohibitions of practices,
maintenance procedures, and other managementpractices to prevent or reduce the pollution of
waters of the Commonwealth. BMPs also include treatment requirements, operating_ procedures,
and practices to control stormwater runoff.
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.
Green Infrastructure. An adaptable term used to describe an array of products technologies and
practices that use natural systems - or engineered systems that mimic natural processes - to
enhance overall environmental quality and provide utility services Asaeg neral principal Green
Infrastructure techniques use soils and vegetation to infiltrate evapotranspirate and/or recycle
stormwater runoff. When used as components of a stormwater management system Green
Infrastructure practices such as green roofs porous pavement rain gardens and vegetated swales
can produce a variety of environmental benefits.
High Quality Waters or HOW. Those "Waters of the Commonwealth" that have been categorized
by the Kentucky Division of Water as high quality pursuant to the requirements of 401 KAR
10:030, Section 1(3).
Impaired Waters or IW. Those "Waters of the Commonwealth" that have been categorized by the
Kentucky Division of Water as impaired for applicable designated uses and have been identified
pursuant to 33 U.S.C. 1315 (b) and listed in the most recent 305 (b) report
Impervious surface. [Asphalt, eener-ete-oma any other- suFfaee whiek d��Q allow��� le
infiltration of stenn water-.] Surfaces that prevent or significantly impede the natural infiltration of
stormwater into the soil including but not limited to roofs sidewalks walkways patios private
driveways parking lots access extensions alleys and other paved engineered compacted or
ravel.
Kentucky Pollutant Discharge Elimination System or KPDES The Kentucky program for issuing,.
modifying, revoking and reissuing revoking monitoring and enforcing permits to discharge, and
imposing and enforcing pretreatment requirements.
KPDES sMS4 Permit. The general permit issued by the Kentucky Division of Water (KDO that
authorizes small Municipal Separate Storm Sewer Systems (sMS4) to discharge stormwater runoff
from a small Municipal Separate Storm Sewer System (MS4) to the receiving waters of the
Commonwealth in accordance with effluent limitations monitoring requirements and other
conditions set forth in the permit authorizing the MS4 to discharge under the Kentucky Pollutant
Discharge Elimination System.
Land disturbance activity or Land disturbing activity. Any clearing_ grubbing grading excavating,
filling, or other alteration of the earth's surface where natural or manmade ground cover is
destroyed. Land disturbance activity does not include the following_
(1) Minor land disturbance activities including but not limited to activities specific to
underground utility repairs replacement of existing utilities home gardens minor repairs and
maintenance work.
(2) Installation of fence, sign, telephone, and electric poles and other kinds of posts orop les.
(3) Emergency work to protect life, limb, or property and emergency repairs.
Larger common plan of development or sale. A contiguous area where multiple separate and
distinct construction activities are planned to occur at different times on different schedules under
one plan, e.g., a housing development of 5 1/4 -acre lots.
Municipal Separate Storm Sewer System. A conveyance or system of conveyances (including
roads with drainage systems, municipal streets, catch basins, curbs gutters ditches man-made
channels and storm drains) owned or operated by a state city, town county, district association
or other public body (created by or pursuant to state law l having_ jurisdiction over disposal of
sewage, industrial water, stormwater, or other wastes that discharges to waters of the United
States:
2
(1) designed or used for collecting or conveying- stormwater;
(2) which is not a combined sewer; and
(3) which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2.
sMS4 is an acronym for a "small municipal separate storm sewer system. MS4 is an acron i for
a "municipal separate storm sewer system."
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.
National Pollutant Discharge Elimination System or NPDES The effluent permitting program for
point source discharges that is administered by the United States Environmental Protection A eg_pgy
USEPA .
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.
Stormwater. Stormwater runoff, snowmelt runoff, surface runoff and drainage.
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.
TMDL. Is an acronym for "Total Maximum Daily Load", a federally mandated program for
impaired waters of the Commonwealth to determine the maximum assimilative capacity
water for a specified pollutant and to allocate allowable pollutant loads to sources in the
watershed.
Waters of the Commonwealth. Means and includes any and all rivers, streams, creeks, lakes,
ponds, impounding reservoirs, springs, wells, marshes, and all other bodies of surface or
underground water, natural or artificial, situated wholly or partly within or bordering upon the
Commonwealth or within its jurisdiction.
Waters of the United States. As defined by the Clean Water Act, applies only to surface waters,
rivers, lakes, estuaries, coastal waters and wetlands. Not all surface waters are legally "Waters of
the United States". Generally those waters include the following:
(1) All interstate waters
(2) Intrastate waters used in interstate and/or foreign commerce
(3) Tributaries of the above
(4) Territorial seas at the cyclical high tide mark, and
(5) Wetlands adjacent to all of the above.
Water -Quality Control Facilities. The facilities (e.g. grass swales, filter strips, infiltration basins,
detention ponds stormwater wetlands, natural filtration areas, sand filters, and rain gardens,
etc.) used to slow runoff, promote infiltration, and reduce sediments and other pollutants in
stormwater runoff.
Water Quality Runoff Volume a Mv). The storm water volume to be treated through a water
quality control facility based on the surface runoff produced by an 80th percentile rainfall event.
Sec. 50-153. Stormwater conveyance, management, and water quality facilities required.
The requirements in this article shall apply to:
(1) All land -disturbing activities and all development or redevelopment activities that disturb an
area greater than or equal to one acre.
(2) Sites that are smaller than one acre may also be covered by these regulations if they are a part
of a larger common plan of development or sale.
(3) [A.-ty nen&esidepAial develepmeiA for which the area paved ar"i'a- tmderTe f is equal to of
gre-ate• than 10,000 square feet.] Any development or redevelopment project that adds 10,000
square feet or more of impervious surface.
(4) At the discretion of the City Engineer this article may apply to any existing nonresidential
redevelopment project for which the total impervious area of the propertyequal to or greater
than 10,000 square feet.
These regulations shall apply to land -disturbing activities within the jurisdictional boundaries of
the City of Paducah designated by the Kentucky Division of Water for coverage under the KPDES
[8]jMS4 permit.
Unless included in exemptions listed in section 50-155 or a waiver granted, all development
occurring within the City and subject to this article shall provide for properly sized stormwater
conveyance facilities capable of controlling peak discharge rates for selected design storms [to] at
or less than pre -developed conditions. Additionally all projects, meeting the criteria in items (1)
and (2) above, that disturb one or more acres of land including_ parcels that are part of a larger
common plan of development shall provide water quality control facilities that shall contain on-
site, or provide off-site, stormwater management facilities capable of managing the storm water
runoff quality produced from an 80th percentile rainfall event under post -construction conditions
Sec. 50-154. Stormwater conveyance facilities and water quality control facilities design
criteria.
The following criteria shall control when designing stormwater conveyance facilities and water
quality control 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 subsection (4) below.
(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.
M
-
-
- - _11
rMIMMI-
Sec. 50-154. Stormwater conveyance facilities and water quality control facilities design
criteria.
The following criteria shall control when designing stormwater conveyance facilities and water
quality control 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 subsection (4) below.
(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.
M
(5) Erosion control. Plans for stormwater conveyance systems shall include the applicable
provisions identified under Article IV, Erosion Prevention and Sediment Control, of this chapter.
(6) Water Quality Control Facilities. The design rainfall event for the design of all stormwater
quality control facilities shall be the surface depth of runoff produced from an 80th percentile
precipitation event. Storm water quality control facilities shall be designed built and maintained
to treat, filter, flocculate, infiltrate, screen, evapo-transpire, harvest, and reuse stormwater runoff,
or otherwise manage the stormwater runoff quality for the 80"' percentile precipitation event.
Green Infrastructure devices may be used as water quality control facilities if it meets the design
criteria.
(7) Design certification. Design of all stormwater conveyance and water quality 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 and City of Paducah Design Standards.
Sec. 50-155. Stormwater management and water quality control facilities design criteria.
As a minimum, the following criteria shall be followed when designing a stormwater management
facilities and water quality control facilities:
(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. Stormwater
management facilities that discharge to High Quality Waters shall be designed to retain the
difference in the pre -development and post -development two-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) Gradient. All detention basins having a vegetative cover shall be designed, constructed, and
maintained equal to or greater than one percent throughout to the point of discharge.
(5) Stormwater management and water qualio�plan. The final stormwater management and water
quality 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
facilities and water quality control facilities.
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
and water quality control facilities.
e. All information relative to the design and operation of emergency spillways.
f. Project specifications relative to erosion and sedimentation control.
g. All deed restrictions, easements and rights-of-way
h. The ownership and maintenance responsibilities for all stormwater management and water
quality control facilities during and after development. The identity of the responsible individual,
corporation, association or other specific entity and the specific maintenance activities and
schedule must be outlined on the plan.
i. Storm water management and water quality control facilities shall be designed to minimize water
quality impacts and shall attempt to maintain pre -development runoff conditions
j. Storm water quality control facilities shall be designed to effectively treat the required amount
of water quality runoff volume for the developed site
(6) Exemptions. Exemptions from the stormwater management requirements contained herein
shall be granted to the following:
a. 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,
grains 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 grazing 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 stormwater management plan prior
to the start of the land -disturbing activity.
b. 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.
e. Any nonresidential development for which the area paved and under roof is less than 10,000
square feet.
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 City
Engineer, based upon interpretation of the documentation presented by the developer in
conjunction with his or her knowledge of the relationship of the proposed development to the
adjacent property.
(7) Design certification. Design of all stormwater management and conveyance facilities and
water quality control facilities shall be prepared and stamped by a Kentucky licensed professional
engineer [(Ke_"_lueky registration required) .
(8) Construction certification. Prior to final approval of the development, the licensed
professional engineer must submit certification that the stormwater management []_,
conveyance facilities and water quality control facilities were constructed in accordance with the
approved plan. Final approval shall also provide evidence of the recording of all stormwater
conveyance, management, and water quality 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.
(9) Ownership, operation and maintenance of stormwater control and water quality control
facilities . For all developments requiring stormwater control and water quality control facilities,
ownership and maintenance responsibilities remain with the property owner/developer. The
Declaration of Maintenance Obligations must be signed, notarized, and submitted with the
stormwater quality management plan.
(10) Additional Treatment And Monitoring May Be Required. The City reserves the right to
require for new and redeveloped properties superseding or additional treatment criteria or
objectives for specific pollutant(s) as necessary to meet overall storm water qualitymanagement
program objectives or directives under a watershed improvement or Total Maximum Daily Load
(TMDL) program or KPDES/NPDES permit program as administered by the USEPA or
Commonwealth of Kentucky.
(11) SeZtlnspection Required. The property owner shall provide self -inspection documentation
for water quality control facilities. The City Engineer or his/her designee will periodically
inspect water quality control facilities for the purpose of identifying maintenance and structural
deficiencies and if required proof of monitoring. If additional treatment and or monitoring is
required, the property owner shall be fully responsible for monitoring their storm water
management and water quality facilities in accordance with the most recent directives under a
watershed improvement or Total Maximum Daily Load Program or KPDES/NPDES permit
program as administered by the USEPA or Commonwealth of Kentucky. In the event a
deficiencv is discovered a Notice of Violation will be issued and shall be enforced under Citv of
Paducah Code of Ordinances Chapter 42 Article II.
(12) In Lieu o Fee or Off Site Mitigation Program May Be Established. The City of Paducah
Engineering and Public Works may develop a payment -in -lieu program to allow property
owners/developers make payment to the City in lieu of constructing storm water quality control
facilities. The in lieu of fee funds shall be applied to public storm water projects. Another option
is to allow the property owner/developer to provide off site mitigation in the same watershed.
Both of these options may be developed by the City of Paducah Engineering and Public Works
Department following the permit requirements of the KPDES Permit For Small Municipal
Separate Storm Sewer Systems.
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 fully complied with.
Sec. 50-157. Penalty.
Any person, firm, corporation or agency acting as principal, agent, employee or otherwise, who
fails to comply with the provisions of this article shall be guilty of a misdemeanor and upon
conviction thereof shall be punishable by a fine of not less than $100.00 per day and not more than
$500.00 per day, or by imprisonment for not more than 90 days, or both, for each separate offense.
Each day there is a violation of any part of this article shall constitute a separate offense.
SECTION 2. SEVERABILITY. If any section, paragraph or provision of this Ordinance shall
be held to be invalid or unenforceable for any reason, the invalidity or unenforceability of such
section, paragraph or provision shall not affect any of the remaining provisions of this
Ordinance.
SECTION 3. COMPLIANCE WITH OPEN MEETINGS LAWS. The City Commission
hereby finds and determines that all formal actions relative to the adoption of this Ordinance
were taken in an open meeting of this City Commission, and that all deliberations of this City
Commission and of its committees, if any, which resulted in formal action, were in meetings
open to the public, in full compliance with applicable legal requirements.
VA
SECTION 4. CONFLICTS. All ordinances, resolutions, orders or parts thereof in conflict with
the provisions of this Ordinance are, to the extent of such conflict, hereby repealed and the
provisions of this Ordinance shall prevail and be given effect.
SECTION 5. EFFECTIVE DATE. This Ordinance sh e ead on two separate days and will
become effective upon summary publication uan C4 pter 4a4.
ATTEST:
1rVUA-kA'Nn'k G�
ity Clerk
Introduced by the Board of Commissioners, February 23, 2021
Adopted by the Board of Commissioners, March 9, 2021
Recorded by City Clerk, March 9, 2021
Published by The Paducah Sun, March 12, 2021
ORD\50-151 Stormwater sMS4 Permit
Prepared by Strand Associates, Inc.
N.
I
I