HomeMy WebLinkAboutOrd.5070.04-16-2018 BILL NO. 18-44 ORDINANCE NO. 5070
AN ORDINANCE AMENDING CHAPTER 23 OF THE
CODE OF ORDINANCES OF THE CITY OF CAPE
GIRARDEAU, MISSOURI, RELATING TO
STORMWATER MANAGEMENT REGULATIONS
BE IT ORDAINED BY THE COUNCIL OF THE CITY OF CAPE
GIRARDEAU, MISSOURI, AS FOLLOWS:
ARTICLE 1 . Section 23-1 of the Code of Ordinances of
the City of Cape Girardeau, Missouri, entitled
"Definitions", reading as follows :
Sec. 23-1 . - Definitions .
As used in this chapter, the following definitions apply:
Adverse impact. Any modifications, alterations, or effects on
a feature or characteristic of surface waters including their
quality, quantity, hydrodynamics, surface area, species
composition, living resources, aesthetics or usefulness for
human or natural uses which are or may potentially be harmful or
injurious to human health, welfare, safety or property, to
biological productivity, diversity, or stability, or which
unreasonably interfere with the enjoyment of life or property,
including outdoor recreation. The term includes secondary and
cumulative, as well as direct impacts .
Applicant . The record owner, or his authorized
representative, of a tract of land that is the site of
development, or development activity within the scope of this
chapter.
Base flood elevation. The elevation at any location
delineating high waters having a one (1) percent probability of
being equaled or exceeded in any given year, as determined by
FEMA and described on the flood insurance rate maps (FIRMs) .
Best management practice (BMP) . Any physical, chemical or
managerial practice that reduces soil erosion or reduces the
amount of sediment or other pollutants discharging to or
potentially discharging to the MS4 . There are structural and
nonstructural BMPs .
Building. Any structure built for the support, shelter or
enclosure of persons, animals, chattels or movable property of
any kind.
1
Capacity of a storm drainage facility. The maximum ability of
a storm drainage facility to convey, detain or retain stormwater
flows without causing substantial damage to public or private
property, and in the case of a pipe, without surcharging.
Channel. A natural or artificial open watercourse with
definite bed and banks which periodically or continuously
contains moving water or which forms a connecting link between
two (2) bodies of water.
Clearing. The act of removing trees or vegetation from a
tract of land and disturbing soil conditions.
Conduit. Any channel, pipe, sewer or culvert used for the
conveyance or movement of water, whether open or closed.
Control device. An element of a discharge structure which
allows the gradual release of water under controlled conditions.
Control elevation. The design elevation of a discharge
structure at which, or below which, water is contained behind
the structure.
CPESC. Certified professional in erosion and sediment
control.
Detention. The delay of storm runoff prior to discharge into
receiving waters.
Detention basin. A facility constructed or modified to
restrict the discharge of stormwater to a prescribed maximum
rate, and to concurrently detain the excess waters that
accumulate behind the outlet. A wet bottom detention basin is a
structure designed to retain a permanent pool of water after
having provided its planned detention of runoff during a storm
event. A dry bottom detention basin is designed to be completely
dewatered after having provided its planned detention of runoff
during a storm event.
Detention storage. The temporary detaining or storage of
stormwater in storage basins, or rooftops, in streets, parking
lots, school yards, parks, open space, or other areas under
predetermined and controlled conditions, with the rate of
drainage therefrom regulated by appropriately installed devices.
Detention volume. The volume of
between the control elevation of
maximum level at which water c
discharge times the average ar
(between the control elevation a
discharge structure.
2
water equal to the difference
discharge structure and the
in be accumulated prior to
a of open surface storage
d maximum level) behind the
Developer. Any individual, firm, corporation, association,
partnership, or other entity involved in commencing proceedings
under this chapter to effect the development of land for himself
or another.
Development or development activity. Any manmade change to
improved or unimproved land, including, but not limited to,
buildings or other structures, mining, dredging, filling,
grading, paving, excavation, or drilling operation. Any
subdivision of land as defined in the city's subdivision
regulations, excluding minor subdivisions.
Differential runoff. The difference in rate and volume of
stormwater runoff from a parcel or project in its undeveloped
natural condition and its developed condition is known as the
differential runoff.
Discharge. The rate of outflow of water from detention
storage.
Discharge structure. A structural device, usually of
concrete, metal, timber, etc., through which water is discharged
from a project to the receiving water.
Drainage area. The area from which water is carried off by a
drainage system; a watershed or catchment area.
Drainage easement. An easement for the sole purpose of
allowing water to flow through it. The city shall not be
responsible for maintenance in a drainage easement.
Drainage and maintenance easement. An easement for the
purpose of allowing water to flow through it. The city shall be
responsible for maintenance in a drainage and maintenance
easement.
Drainage facility. An element in a drainage system which
includes, but is not limited to, any of the following: conduits
and appurtenant features, canals, channels, detention basins,
ditches, streams, culverts, streets and pumping stations.
Drainage system. The surface or subsurface system which
conveys water from or over the land, including all watercourses,
water bodies and wetlands (also referred to as the "stormwater
management system").
Easement. A grant by a property owner to the public, a
corporation, or a person of the use of land for a specific
purpose.
Elevation. The height in feet above mean sea level according
to National Geodetic Vertical Datum (NGVD).
3
Emergency spillway. A saddle or low point facility located
around the rim of a dammed impoundment such as a detention or
retention basin for providing an efficient and safe means of
conveying the maximum design flood discharge through the
impoundment, without overtopping the dam.
Erosion. The wearing away of the land surface by the action
of the wind, water, ice, gravity, or any combination thereof.
Excess stormwater runoff. The volume and rate of flow of
stormwater discharged from a drainage area which is or will be
in excess of that volume and rate which is specified in this
chapter.
Fifteen -year storm. A rainstorm of varying duration and
intensity having a 6.67 percent probability of being equaled or
exceeded in any given year.
Filling. To place soil, rock, or other material over the
natural topography of a site such that the natural grade and/or
elevation is altered.
Floodplain. The special flood hazard land adjoining a
watercourse, the surface elevation of which is equal to or lower
than the base flood elevation (the 100 -year flood), which is
subject to periodic inundation during floods.
Flood fringe. The higher portion of the floodplain,
immediately adjacent to and on either side of the floodway,
occupied by quiescent or slow moving waters during floods.
Floodway. The channel of a watercourse and those portions of
the adjoining floodplain which are reasonably required to carry
and discharge the base flood.
Grading. To level or smooth to a desired or horizontal
gradient.
High-water elevation. The elevation of floodwaters of a flood
of specified frequency or occurrence at any given point.
Illicit discharge. Any direct or indirect discharge to the
city's MS4 that is not composed entirely of stormwater, unless
exempt pursuant to city ordinance.
Impervious surface. A surface which has been compacted or
covered with a layer of materials so that it is highly resistant
to infiltration of water. The term includes most conventionally
surfaced streets, roofs, sidewalks, parking lots and similar
structures.
Improvement. A structure on, or other alteration of land on a
given site, including, but not limited to, grading, street
paving, storm sewers, sanitary sewers and utilities.
M
MS4. Municipal separate storm sewer system.
Natural watercourse. A channel that is formed through the
natural flow of stormwater runoff influenced by area topography.
The channel can carry a flow of water continuously or
intermittently. Such a channel can include but not be limited to
swales, streams, creeks, gullies, ravines, or rivers of varying
depths and lengths. These channels carry a stream of water which
flows along a naturally defined path, usually with a bed and
banks. It should, on casual examination, present the
unmistakable evidence of the frequent action of running water.
If the flow of water occurs periodically from natural causes and
reaches a plainly defined channel of a permanent character, this
is sufficient to establish a natural watercourse. A natural
watercourse may be altered through construction or development
activities, and yet remain a natural watercourse.
Off-site detention basin. A feature or structure for
temporarily storing excess stormwater originating at two (2) or
more sites having devices for controlling the rate of release of
the stored water, and located downstream of all sites where the
runoff originates.
100 -year storm. A rainstorm of varying duration and intensity
having a one (1) percent probability of recurring in any one (1)
year.
On-site detention basin. A feature or structure for
temporarily storing excess stormwaters, having devices for
controlling the rate of release of the stored waters, and
located within the sites where the runoff originates.
Overflow elevation. A design elevation of a discharge
structure at which point, or above which point, water leaks out,
or bleeds out, through a control device down to the control
elevation.
Pass-through flow. Off-site water that is allowed to move
through a detention basin without being detained or included in
the detention calculations.
Peak flow. The maximum rate of flow of water at a given point
in a channel or conduit resulting from a predetermined storm or
flood.
Post -development conditions. Those conditions which are
expected to exist, or do exist, after alteration, resulting from
human activity, of the natural topography, vegetation and rate,
volume or direction of surface or subsurface flow.
Predevelopment conditions. Those conditions which exist at a
site prior to any alteration of the natural topography,
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vegetation, flow rate, flow volume, or direction of surface or
subsurface flow. In the case of a site where development has
occurred in the past the predevelopment condition shall be the
physical conditions of the site at the time of the application
for the permit.
Primary drainage (water management) systems. Includes major
waterways and appurtenant structures or systems whose total
tributary area from origin to outfall exceeds or equals fifty
(50) acres.
Professional engineer or architect. An engineer or architect
duly registered or otherwise authorized by the state to practice
engineering.
Project site. Any site where construction activity will
result in land disturbance by means of filling, clearing,
excavating and/or grading.
Rational method. An empirical formula for calculating peak
rates of runoff resulting from rainfall. Expressed
mathematically, the formula is:
Q = CIA
Where:
Q = Peak flow in cubic feet per second (cfs)
C = Runoff coefficient or fraction of runoff to rainfall,
dependent on type of surface cover and topography
I = Rainfall intensity, in inches per hour, for a specific
storm and duration
A = Watershed area in acres
Receiving bodies of water. Any water body or stream into
which surface waters flow.
Sedimentation. The process by which suspended solids from
erosion are transported and deposited.
Site plan. The plan, usually in map form, prepared pursuant
to the city council's zoning or other land development
ordinances as a requirement for the development of property.
Stormwater pollution prevention plan (SWPPP). A plan
developed by a qualified professional engineer or person
certified in erosion and sediment control to establish controls
to limit erosion and transport of sediment and other pollutants
from a project site. The plan shall include the use of best
management practices.
0
Stormwater runoff. The waters derived from rain falling or
snow melting within a tributary drainage basin, flowing over the
surface of the ground or collected in a stormwater drainage
system, storm sewer or watercourse.
Subdivision. As defined in chapter 25 of this Code.
Time of concentration. The elapsed time for stormwater to
flow from the most distant point in a drainage basin to the
outlet or point in question.
Twenty -five-year storm. A rainstorm of varying duration and
intensity having a four (4) percent probability of being equaled
or exceeded in any given year.
Watercourse. Any stream, creek, brook, branch, natural or
artificial depression, slough, gulch, reservoir, lake, pond or
natural or manmade drainageway in or into which stormwater
runoff and floodwaters flow either regularly or intermittently.
Watershed.
(a) An area of land that drains down slope to a lowest
point. Water shed boundaries follow major ridgelines
around channels and meet at the bottom, where water flows
out of the watershed, a point commonly referred to as a
channel, stream, creek, or river.
(b) A region or area bounded peripherally by a topographic
divide and draining ultimately to a particular watercourse
or body of water.
is hereby repealed in its entirety, and a new Section 23-1
entitled "Definitions" is hereby enacted in lieu thereof, in
words and figures, to read as follows:
Sec. 23-1. - Definitions
As used in this chapter, the following definitions apply:
Adverse impact. Any modifications, alterations, or effects on
a feature or characteristic of surface waters including their
quality, quantity, hydrodynamics, surface area, species
composition, living resources, aesthetics or usefulness for
human or natural uses which are or may potentially be harmful or
injurious to human health, welfare, safety or property, to
biological productivity, diversity, or stability, or which
unreasonably interfere with the enjoyment of life or property,
including outdoor recreation. The term includes secondary and
cumulative, as well as direct impacts.
7
Applicant. The record owner, or his authorized
representative, of a tract of land that is the site of
development, or development activity within the scope of this
chapter.
Base flood elevation. The elevation at any location
delineating high waters having a one (1) percent probability of
being equaled or exceeded in any given year, as determined by
FEMA and described on the flood insurance rate maps (FIRMS).
Best management practice (BMP). Any physical, chemical or
managerial practice that reduces soil erosion or reduces the
amount of sediment or other pollutants discharging to or
potentially discharging to the MS4. There are structural and
nonstructural BMPs.
Building. Any structure built for the support, shelter or
enclosure of persons, animals, chattels or movable property of
any kind.
Capacity of a storm drainage facility. The maximum ability of
a storm drainage facility to convey, detain or retain stormwater
flows without causing substantial damage to public or private
property, and in the case of a pipe, without surcharging.
Channel. A natural or artificial open watercourse with
definite bed and banks which periodically or continuously
contains moving water or which forms a connecting link between
two (2) bodies of water.
Clearing. The act of removing trees or vegetation from a
tract of land and disturbing soil conditions.
Conduit. Any channel, pipe, sewer or culvert used for the
conveyance or movement of water, whether open or closed.
Control device. An element of a discharge structure which
allows the gradual release of water under controlled conditions.
Control elevation. The design elevation of a discharge
structure at which, or below which, water is contained behind
the structure.
CPESC. Certified professional in erosion and sediment
control.
Detention. The delay of storm runoff prior to discharge into
receiving waters.
Detention basin. A facility constructed or modified to
restrict the discharge of stormwater to a prescribed maximum
rate, and to concurrently detain the excess waters that
accumulate behind the outlet. A wet bottom detention basin is a
structure designed to retain a permanent pool of water after
having provided its planned detention of runoff during a storm
event. A dry bottom detention basin is designed to be completely
dewatered after having provided its planned detention of runoff
during a storm event.
Detention storage. The temporary detaining or storage of
stormwater in storage basins, or rooftops, in streets, parking
lots, school yards, parks, open space, or other areas under
predetermined and controlled conditions, with the rate of
drainage therefrom regulated by appropriately installed devices.
Detention volume. The volume of
between the control elevation of
maximum level at which water c
discharge times the average ar
(between the control elevation a
discharge structure.
water equal to the difference
discharge structure and the
in be accumulated prior to
a of open surface storage
d maximum level) behind the
Developer. Any individual, firm, corporation, association,
partnership, or other entity involved in commencing proceedings
under this chapter to effect the development of land for himself
or another.
Development or development activity. Any manmade change to
improved or unimproved land, including, but not limited to,
buildings or other structures, mining, dredging, filling,
grading, paving, excavation, or drilling operation. Any
subdivision of land as defined in the city's subdivision
regulations, excluding minor subdivisions.
Differential runoff. The difference in rate and volume of
stormwater runoff from a parcel or project in its undeveloped
natural condition and its developed condition is known as the
differential runoff.
Discharge. The rate of outflow of water from detention
storage.
Discharge structure. A structural device, usually of
concrete, metal, timber, etc., through which water is discharged
from a project to the receiving water.
Drainage area. The area from which water is carried off by a
drainage system; a watershed or catchment area.
Drainage easement. An easement for the sole purpose of
allowing water to flow through it. The city shall not be
responsible for maintenance in a drainage easement.
Drainage and maintenance easement. An easement for the
purpose of allowing water to flow through it. The city shall be
responsible for maintenance in a drainage and maintenance
easement.
0
Drainage facility. An element in a drainage system which
includes, but is not limited to, any of the following: conduits
and appurtenant features, canals, channels, detention basins,
ditches, streams, culverts, streets and pumping stations.
Drainage system. The surface or subsurface system which
conveys water from or over the land, including all watercourses,
water bodies and wetlands (also referred to as the "stormwater
management system").
Easement. A grant by a property owner to the public, a
corporation, or a person of the use of land for a specific
purpose.
Elevation. The height in feet above mean sea level according
to National Geodetic Vertical Datum (NGVD).
Emergency spillway. A saddle or low point facility located
around the rim of a dammed impoundment such as a detention or
retention basin for providing an efficient and safe means of
conveying the maximum design flood discharge through the
impoundment, without overtopping the dam.
Erosion. The wearing away of the land surface by the action
of the wind, water, ice, gravity, or any combination thereof.
Excess stormwater runoff. The volume and rate of flow of
stormwater discharged from a drainage area which is or will be
in excess of that volume and rate which is specified in this
chapter.
Filling. To place soil, rock, or other material over the
natural topography of a site such that the natural grade and/or
elevation is altered.
Filtration Trench. An element of stormwater management that
acts in the manner of a french drain. It shall be a trench
sized to the site requirements and filled with clean 2 inch
minimum stone with no fines. The air spaces in the stone allow
the site stormwater runoff to filter through the trench to
remove various pollutants. The trench will have an outflow pipe
a minimum of 6 inches from the bottom of the trench.
Floodplain. The special flood hazard land adjoining a
watercourse, the surface elevation of which is equal to or lower
than the base flood elevation (the 100 -year flood), which is
subject to periodic inundation during floods.
Flood fringe. The higher portion of the floodplain,
immediately adjacent to and on either side of the floodway,
occupied by quiescent or slow moving waters during floods.
10
Floodway. The channel of a watercourse and those portions of
the adjoining floodplain which are reasonably required to carry
and discharge the base flood.
Grading. To level or smooth to a desired or horizontal
gradient.
High-water elevation. The elevation of floodwaters of a flood
of specified frequency or occurrence at any given point.
Illicit discharge. Any direct or indirect discharge to the
city's MS4 that is not composed entirely of stormwater, unless
exempt pursuant to city ordinance.
Impervious surface. A surface which has been compacted or
covered with a layer of materials so that it is highly resistant
to infiltration of water. The term includes most conventionally
surfaced streets, roofs, sidewalks, parking lots and similar
structures.
Improvement. A structure on, or other alteration of land on a
given site, including, but not limited to, grading, street
paving, storm sewers, sanitary sewers and utilities.
MS4. Municipal separate storm sewer system.
Natural watercourse. A channel that is formed through the
natural flow of stormwater runoff influenced by area topography.
The channel can carry a flow of water continuously or
intermittently. Such a channel can include but not be limited to
swales, streams, creeks, gullies, ravines, or rivers of varying
depths and lengths. These channels carry a stream of water which
flows along a naturally defined path, usually with a bed and
banks. It should, on casual examination, present the
unmistakable evidence of the frequent action of running water.
If the flow of water occurs periodically from natural causes and
reaches a plainly defined channel of a permanent character, this
is sufficient to establish a natural watercourse. A natural
watercourse may be altered through construction or development
activities, and yet remain a natural watercourse.
NOAA. National Oceanic and Atmospheric Administration.
Off-site detention basin. A feature or structure for
temporarily storing excess stormwater originating at two (2) or
more sites having devices for controlling the rate of release of
the stored water, and located downstream of all sites where the
runoff originates.
100 -year storm. A rainstorm of varying duration and intensity
having a one (1) percent probability of recurring in any one (1)
year.
11
On-site detention basin. A feature or structure for
temporarily storing excess stormwaters, having devices for
controlling the rate of release of the stored waters, and
located within the sites where the runoff originates.
Overflow elevation. A design elevation of a discharge
structure at which point, or above which point, water leaks out,
or bleeds out, through a control device down to the control
elevation.
Pass-through flow. Off-site water that is allowed to move
through a detention basin without being detained or included in
the detention calculations.
Peak flow. The maximum rate of flow of water at a given point
in a channel or conduit resulting from a predetermined storm or
flood.
Post -development conditions. Those conditions which are
expected to exist, or do exist, after alteration, resulting from
human activity, of the natural topography, vegetation and rate,
volume or direction of surface or subsurface flow.
Predevelopment conditions. Those conditions which exist at a
site prior to any alteration of the natural topography,
vegetation, flow rate, flow volume, or direction of surface or
subsurface flow. In the case of a site where development has
occurred in the past the predevelopment condition shall be the
physical conditions of the site at the time of the application
for the permit.
Primary drainage (water management) systems. Includes major
waterways and appurtenant structures or systems whose total
tributary area from origin to outfall exceeds or equals fifty
(50) acres.
Professional engineer or architect. An engineer or architect
duly registered or otherwise authorized by the state to practice
engineering.
Project site. Any site where construction activity will
result in land disturbance by means of filling, clearing,
excavating and/or grading.
Rational method. An empirical formula for calculating peak
rates of runoff resulting from rainfall. Expressed
mathematically, the formula is:
Q = CIA
Where:
Q = Peak flow in cubic feet per second (cfs)
12
C = Runoff coefficient or fraction of runoff to rainfall,
dependent on type of surface cover and topography
I = Rainfall intensity, in inches per hour, for a specific
storm and duration
A = Watershed area in acres
Receiving bodies of water. Any water body or stream into
which surface waters flow.
Sedimentation. The process by which suspended solids from
erosion are transported and deposited.
Site plan. The plan, usually in map form, prepared pursuant
to the city council's zoning or other land development
ordinances as a requirement for the development of property.
Stormwater pollution prevention plan (SWPPP). A plan
developed by a qualified professional engineer or person
certified in erosion and sediment control to establish controls
to limit erosion and transport of sediment and other pollutants
from a project site. The plan shall include the use of best
management practices.
Stormwater runoff. The waters derived from rain falling or
snow melting within a tributary drainage basin, flowing over the
surface of the ground or collected in a stormwater drainage
system, storm sewer or watercourse.
Subdivision. As defined in chapter 25 of this Code.
Ten-year Storm. A rainstorm of varying duration and intensity
having a 10 percent probability of being equaled or exceeded in
any given year.
Time of concentration. The elapsed time for stormwater to
flow from the most distant point in a drainage basin to the
outlet or point in question.
Twenty -five-year storm. A rainstorm of varying duration and
intensity having a four (4) percent probability of being equaled
or exceeded in any given year.
Watercourse. Any stream, creek, brook, branch, natural or
artificial depression, slough, gulch, reservoir, lake, pond or
natural or manmade drainageway in or into which Stormwater
runoff and floodwaters flow either regularly or intermittently.
Watershed.
(a) An area of land that drains down slope to a lowest
point. Water shed boundaries follow major ridgelines
around channels and meet at the bottom, where water flows
13
out of the watershed, a point commonly referred to as a
channel, stream, creek, or river.
(b) A region or area bounded peripherally by a topographic
divide and draining ultimately to a particular watercourse
or body of water.
ARTICLE 2. Section 23-6 of the Code of Ordinances of the
City of Cape Girardeau, Missouri, entitled "Stormwater
management plan", reading as follows:
Sec. 23-6. - Stormwater management plan.
A stormwater management plan, including the SWPPP, is to be
designed to safely manage the stormwater runoff for quantity and
quality during and after construction. The plan shall be
designed to manage the quality of stormwater runoff during
development through erosion and sedimentation controls and after
development through post construction design elements. The SWPPP
is to be prepared and sealed by a professional engineer licensed
in the State of Missouri or a CPESC. The plan shall provide or
be accompanied by maps at a minimum scale of one (1) inch is
less than or equal to two hundred (200) feet and other
descriptive material, including the basis of computation,
showing the following:
(1) Required predevelopment site information (map scales are
minimums):
a. Detailed location sketch showing the parcel and
major adjacent roads.
b. Topographic map of the site at a scale of one (1)
inch is less than or equal to two hundred (200) feet
with maximum five-foot contour intervals, except in
floodplains or other areas of low relief where a
smaller interval may be required.
C. Where percolation or exfiltration systems are
proposed, information as to the location and type of
vegetative cover and soil types and characteristics
representative of the design condition mapped at a
scale of one (1) inch is less than or equal to two
hundred (200) feet.
d. Location of streams and other floodwater runoff
channels, their normal channels, and the extent of the
floodplains at the established high water elevations,
and the limits of the floodway mapped at a scale of one
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(1) inch is less than or equal to two hundred (200)
feet.
e. Location of lakes, ponds, swamps and detention
basins indicating their normal shorelines, floodplains
and lines of inflow and outflow mapped at a scale of
one (1) inch is less than or equal to two hundred (200)
feet.
f. Location of farm drains, inlets and outfalls, storm
sanitary and combined sewers and outfalls, septic tank
systems and outlets, if any, and seeps, springs and
flowing and other wells mapped at a scale of one (1)
inch is less than or equal to two hundred (200) feet.
g. Location and description of nearby existing off-
site water management facilities such as wells, lakes,
drainageways, etc., which are potentially directly
affected by the proposed construction or development,
mapped at a scale of one (1) inch is less than or equal
to two hundred (200) feet.
(2) For all existing drainage facilities which are to be
maintained, altered, or enlarged as part of the stormwater
management system; provide information as to their size,
slopes, depths, outfalls, receiving waters, elevations,
cross sections, profiles, construction materials and other
design details as applicable.
(3) Location of all new stormwater facilities, including
detention basins and post construction water quality
elements, to be constructed. Design details for each
facility shall be provided as applicable.
(4) Location and extent of existing and proposed impervious
surfaces (roads, parking lots, buildings, etc.) and their
elevations. Provide grading and paving plans and
specifications.
(5) Location and extent of rights-of-way and easements for
the stormwater management system, including all areas to
be dedicated for water management purposes.
(6) Identification and description of any special or
required maintenance procedures to keep the project
functioning as designed.
(7) Provide stormwater management system design calculations
as follows:
a. Design storms used.
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b. For all detention basins, a plot or tabulation of
storage volumes with corresponding water surface
elevations and of the basin outflow rates for those
water surface elevations.
C. Acreages and percentage of property proposed as:
1. Impervious surfaces.
2. Pervious surfaces (green areas).
3. Lakes, canals, detention areas, etc.
4. Total acreage of project.
5. Other.
d. Runoff routing calculation showing discharge,
elevations, and volumes retained and/or detained during
applicable storm event.
e. Calculations required for determination of minimum
building floor and road elevations.
f. Calculations for all inlets, pipes, and ditches
shall be submitted for review.
(8) For projects less than one (1) acre, provide a narrative
section that describes potential sources of pollution,
project managers for the project and areas over which they
have control, temporary and permanent nonstructural BMPs,
temporary and permanent structural BMPs, additional site
BMPs as warranted by the site, BMP implementation
schedule, temporary stabilization practices, dewatering
methods, permanent stabilization practices, measures to
minimize dust, construction/waste materials to be stored
on site and how they will be disposed, pollutant sources
from other areas than construction, allowable sources of
nonstormwater discharge, how mud/sediment on streets or
other property will be handled, how accumulated sediment
will be disposed, and implementation of pollution
prevention measures for nonstormwater discharges.
(9) For projects one (1) acre or greater, provide two (2)
bound copies of the SWPPP based on the EPA SWPPP template.
Required information includes identifying contact
information for responsible parties; site evaluation,
assessment and planning; documentation of compliance with
other federal requirements; erosion and sediment controls;
pollution prevention standards; and inspection and
corrective action.
(10) Describe operation and maintenance procedures for
stormwater management facilities, i.e., cleaning
16
frequency, access routes, any special equipment or tools
to be used. This should include procedures for transfer of
maintenance responsibilities where appropriate.
(11) Identify entity responsible for operation and
maintenance of the erosion and sediment control system
after completion of site activities.
(12) The requirements for specific plan elements cited above
may be waived by the city manager or his designee, upon
written supportive recommendation of the city engineer.
The stormwater management plan for minor development
activities may consist of a certification from a
professional engineer, architect or CPESC that the
differential runoff equals zero (0). However, the
developer shall still provide a completed application, the
required review fee and SWPPP for the project site.
(13) The city manager or his designee will ascertain the
completeness of the stormwater management plan
application. The city manager or his designee will return
incomplete applications to the applicant for completion
and resubmission. After determining that the application
is complete, the city manager or his designee will
distribute copies of the application for review and
comment to other persons with special technical expertise
as deemed appropriate. Within a reasonable period after
submission of the completed stormwater management plan
application by the applicant, the city manager or his
designee shall approve, approve with specified conditions,
or deny the application and shall notify the applicant
accordingly. If the stormwater management plan application
is denied or approved with conditions, the city manager or
his designee shall state the reasons for denial or the
specified conditions. If the applicant feels aggrieved due
to the denial or conditions, he may appeal the decision to
the city council.
(14) Once the SWPPP is approved, a copy of it shall be kept
at the construction site at all times. The SWPPP shall be
updated according to progress of the work that disturbs
the soil. Typically this update will be done weekly. It
will be the contractor's responsibility to provide the
means of storing the SWPPP on site.
(15) A stormwater management permit shall be valid for three
(3) years after the date of issuance. If the stormwater
management facilities for which the permit was issued are
not completed within three (3) years, the permittee may
request a renewal of the said permit. The permit renewal
17
fee must be paid in full at the time of the renewal
request. The permit renewal fees are outlined on the city
fee schedule. The city manager or his designee has the
right to approve or deny any permit renewal request.
is hereby repealed in its entirety and a new Section 23-6
entitled "Stormwater mangagement plan", is hereby enacted in
lieu thereof, in words and figures, to read as follows, to -wit:
Sec. 23-6. - Stormwater management plan.
A stormwater management plan, including the SWPPP, is to be
designed to safely manage the stormwater runoff for quantity and
quality during and after construction. The plan shall be
designed to manage the quality of stormwater runoff during
development through erosion and sedimentation controls and after
development through post construction design elements. The SWPPP
is to be prepared and sealed by a professional engineer licensed
in the State of Missouri or a CPESC. The plan shall provide or
be accompanied by maps at a minimum scale of one (1) inch is
less than or equal to two hundred (200) feet and other
descriptive material, including the basis of computation,
showing the following:
(1) Required predevelopment site information (map scales
are minimums):
a. Detailed location sketch showing the parcel and major
adjacent roads.
b. Topographic map of the site at a scale of one (1) inch
is less than or equal to two hundred (200) feet with
maximum five-foot contour intervals, except in
floodplains or other areas of low relief where a
smaller interval may be required.
C. Where percolation
proposed, information
vegetative cover and
representative of the
scale of one (1) inch
hundred (200) feet.
or exfiltration systems are
as to the location and type of
soil types and characteristics
design condition mapped at a
is less than or equal to two
d. Location of streams and other
channels, their normal channels, and
floodplains at the established high
and the limits of the floodway mapped
(1) inch is less than or equal to
feet.
HEZ
floodwater runoff
the extent of the
water elevations,
at a scale of one
two hundred (200)
e. Location of lakes, ponds, swamps and detention basins
indicating their normal shorelines, floodplains and
lines of inflow and outflow mapped at a scale of one
(1) inch is less than or equal to two hundred (200)
feet.
f. Location of farm drains, inlets and outfalls, storm
sanitary and combined sewers and outfalls, septic tank
systems and outlets, if any, and seeps, springs and
flowing and other wells mapped at a scale of one (1)
inch is less than or equal to two hundred (200) feet.
g. Location and description of nearby existing off-site
water management facilities such as wells, lakes,
drainageways, etc., which are potentially directly
affected by the proposed construction or development,
mapped at a scale of one (1) inch is less than or equal
to two hundred (200) feet.
(2) For all existing drainage facilities which are to be
maintained, altered, or enlarged as part of the stormwater
management system; provide information as to their size,
slopes, depths, outfalls, receiving waters, elevations,
cross sections, profiles, construction materials and other
design details as applicable.
(3) Location of all new stormwater facilities, including
detention basins and post construction water quality
elements, to be constructed. Design details for each
facility shall be provided as applicable.
(4) Location and extent of existing and proposed
impervious surfaces (roads, parking lots, buildings, etc.)
and their elevations. Provide grading and paving plans and
specifications.
(5) Location and extent of rights-of-way and easements
for the stormwater management system, including all areas
to be dedicated for water management purposes.
(6) Identification and description of any special or
required maintenance procedures to keep the project
functioning as designed.
(7) Provide stormwater management system design
calculations as follows:
a. Design storms to be used are 10 -year, 25 -year, and
100 -year frequency events, with 30 minute duration.
These storms are defined in the NOAA TP 40 Charts.
b. For all detention basins, a plot or tabulation of
storage volumes with corresponding water surface
19
elevations and of the basin outflow rates for those
water surface elevations.
C. Acreages and percentage of property proposed as:
1. Impervious surfaces.
2. Pervious surfaces (green areas).
3. Lakes, canals, detention areas, etc.
4. Total acreage of project.
5. Other.
d. Runoff routing calculation showing discharge,
elevations, and volumes retained and/or detained during
applicable storm event.
e. Calculations required for determination of minimum
building floor and road elevations.
f. Calculations for all inlets, pipes, and ditches shall
be submitted for review.
(8) For projects less than one (1) acre, provide a
narrative section that describes potential sources of
pollution, project managers for the project and areas over
which they have control, temporary and permanent
nonstructural BMPs, temporary and permanent structural
BMPs, additional site BMPs as warranted by the site, BMP
implementation schedule, temporary stabilization
practices, dewatering methods, permanent stabilization
practices, measures to minimize dust, construction/waste
materials to be stored on site and how they will be
disposed, pollutant sources from other areas than
construction, allowable sources of nonstormwater
discharge, how mud/sediment on streets or other property
will be handled, how accumulated sediment will be
disposed, and implementation of pollution prevention
measures for nonstormwater discharges.
(9) For projects one (1) acre or greater, provide two (2)
bound copies of the SWPPP based on the EPA SWPPP template.
Required information includes identifying contact
information for responsible parties; site evaluation,
assessment and planning; documentation of compliance with
other federal requirements; erosion and sediment controls;
pollution prevention standards; and inspection and
corrective action.
(10) Describe operation and maintenance procedures for
stormwater management facilities, i.e., cleaning
frequency, access routes, any special equipment or tools
20
to be used. This should include procedures for transfer of
maintenance responsibilities where appropriate.
(11) Identify entity responsible for operation and
maintenance of the erosion and sediment control system
after completion of site activities.
(12) The requirements for specific plan elements cited
above may be waived by the city manager or his designee,
upon written supportive recommendation of the city
engineer. The stormwater management plan for minor
development activities may consist of a certification from
a professional engineer, architect or CPESC that the
differential runoff equals zero (0). However, the
developer shall still provide a completed application, the
required review fee and SWPPP for the project site.
(13) The city manager or his designee will ascertain the
completeness of the stormwater management plan
application. The city manager or his designee will return
incomplete applications to the applicant for completion
and resubmission. After determining that the application
is complete, the city manager or his designee will
distribute copies of the application for review and
comment to other persons with special technical expertise
as deemed appropriate. Within a reasonable period after
submission of the completed stormwater management plan
application by the applicant, the city manager or his
designee shall approve, approve with specified conditions,
or deny the application and shall notify the applicant
accordingly. If the stormwater management plan application
is denied or approved with conditions, the city manager or
his designee shall state the reasons for denial or the
specified conditions. If the applicant feels aggrieved due
to the denial or conditions, he may appeal the decision to
the city council.
(14) Once the SWPPP is approved, a copy of it shall be
kept at the construction site at all times. The SWPPP
shall be updated according to progress of the work that
disturbs the soil. Typically this update will be done
weekly. It will be the contractor's responsibility to
provide the means of storing the SWPPP on site.
(15) A stormwater management permit shall be valid for
three (3) years after the date of issuance. If the
stormwater management facilities for which the permit was
issued are not completed within three (3) years, the
permittee may request a renewal of the said permit. The
permit renewal fee must be paid in full at the time of the
21
renewal request. The permit renewal fees are outlined on
the city fee schedule. The city manager or his designee
has the right to approve or deny any permit renewal
request.
ARTICLE 3. Section 23-8 of the Code of Ordinances of the
City of Cape Girardeau, Missouri, entitled "General design
requirements for stormwater management plan and SWPPP", reading
as follows:
Sec. 23-8. - General design requirements for stormwater
management plan and SWPPP.
(1) A stormwater management system shall be provided for
protecting lots, roads, streets and buildings in the project
area from the potential adverse impacts of stormwater runoff.
Streets, blocks, depths of lots, parks and other public
grounds, and ultimate land usage shall be determined, located
and laid out in such a manner as to reduce the velocity of
overland flow and allow the maximum opportunity for
infiltration of stormwaters into the ground, and to preserve
and utilize natural streams, channels and detention basins,
and wherever possible, to include streams and floodplains
within parks or other public grounds. The elements of the
stormwater management plan should protect area waterways from
pollutants carried by the stormwater runoff.
(2) The maximum allowable release rate of stormwater after
development shall be as follows:
(a) The rate shall not exceed the before -development rate
for a two-year and ten-year frequency storm.
(b) The twenty -five-year storm shall have the release rate
of a fifteen -year frequency storm.
(c) The total drainage area must be used in calculating the
allowable release rate. The required storage volume will
be based on the project area only, with extraneous flows
from upland areas being pass-through flow or discharged
via overflow spillway or other devices.
(d) The runoff from a one -inch rain event shall be
controlled to provide water quality improvement. This is
approximately the ninetieth percentile rain event.
(3) The increased stormwater runoff resulting from the
proposed development shall be detained on-site by appropriate
detention basins or by other acceptable techniques. The
minimum volume of storage shall be sufficient to store the
volume of the difference between fifteen (15) year storm
22
under undeveloped conditions and the twenty-five (25) year
storm under developed conditions. Control devices shall limit
the discharge from storage to a rate no greater than that
prescribed by this chapter. Downstream property,
watercourses, channels or conduits shall not receive
stormwater runoff from proposed development at a higher peak
flow rate than that which existed prior to the development.
Detention/retention areas should at a minimum filter the
stormwater runoff. When possible, filtration and/or
infiltration practices should be incorporated into the site
design.
(a) Where a development site has more than one (1)
watershed, the runoff water shall be controlled within
each watershed. Exemption from this requirement must be
approved by the city manager or his designee. With a
request for this exemption, the developer will be required
to present information and/or documentation establishing
conclusively that no adverse impacts would occur to
adjoining or downstream properties from uncontrolled
runoff in a particular watershed area of the development
site.
(4) Generally acceptable locations of the stormwater runoff
channels in the design of the project area may include the
following:
(a) In a depressed median of a double roadway, street or
parkway, provided the median is wide enough to permit
required roadway shoulders.
(b) Centered on the rear lot lines in a block, or entirely
within the rear yards of a single row of lots or parcels,
provided that in either case the lots are deep enough to
permit side slopes in the runoff channel and a building
site of the elevation required by other sections of this
chapter.
(c) In a depressed area along roadway, street or parkway,
provided the area is wide enough to permit side slopes as
required in other sections of this chapter.
(d) Landscaped areas may be designed for use as part of the
stormwater management system.
(e) Alternative systems such as curb and gutter and storm
sewers that discharge into an appropriate detention basin
may be incorporated into the stormwater management plan.
(f) The smaller, uppermost reaches of drainage channels and
swales forming the natural drainage system near a
watershed divide may be relocated or eliminated and
23
incorporated into the planned system of storm sewers and
open channels designed consistent with the requirements of
this chapter.
(5) A continuous easement may be provided abutting rear lot
lines as shown in the stormwater management plan within which
utility lines and open drainage facilities may be located and
maintained, but on which no accessory buildings may be
constructed. The utility drainage easement shall be at least
twenty (20) feet wide. Within the area so designed for the
passage or storage of waters, no structure may be erected, no
fences, shrubbery or trees planted, or changes made to the
prescribed grades and contours of the specified floodwater or
stormwater runoff channels.
(6) All storm sewer outfalls shall be so designed, by reason
of elevation of the invert, by a flap gate or by other
features, that when the receiving stream is in full flood,
the storm sewers will continue to drain the areas they are
designed to serve unless the provision is made for sewer
backups into planned storage locations.
(7) All sanitary sewer manholes constructed in a floodplain,
in a street designed for detention, or in an area designed
for the storage or passage of floodwater or stormwater, shall
be provided with either a watertight bolted manhole cover, a
watertight concealed pick -hole cover, or be constructed with
a rim elevation at or above the high water elevation of the
100 -year flood or the high water elevation of the design
storm, whichever is applicable to the specific area.
(8) Projects that are to be developed in phases will
normally require the submission of a master plan of the
applicant's contiguous land holdings. Applications for
individual project phases may be considered only when the
phases are totally independent of, or make sufficient
provisions for, adjacent lands.
(9) All excavations, grading or filling shall have a
finished grade not to exceed a 3:1 (three (3) horizontal to
one (1) vertical) slope. Steeper grades may be approved by
the city engineer if the excavation is through rock or the
excavation or fill is protected (a designed head wall or toe
wall may be required).
(10) Grading plans for sites that exceed one (1) acre shall
provide for erosion control and for sediment controls, or
debris basins, silt traps or filters, staked straw bales, a
combination of these measures or other measures approved by
the city engineer to remove sediment from runoff waters.
Temporary sediment control measures (structural) shall be
24
maintained until vegetative cover is established at a
sufficient density to provide erosion control on the site.
(11) Where natural vegetation is removed during grading,
vegetation shall be reestablished in such a density as to
prevent erosion. Permanent type grasses shall be established
as soon as possible during the next seeding period after
grading has been completed. Trees, plants and vegetative
cover should be of native species, when possible. Reference
the city development manual and other city ordinances for
examples.
(12) When grading operations are completed or suspended for
more than fourteen (14) days between permanent grass seeding
periods, temporary cover shall be provided. All finished
grades (areas not to be disturbed by future improvements) 4:1
slopes or steeper shall be sodded, hydro seeded, or have
erosion control fabric installed; slopes less than 4:1 (four
(4) horizontal to one (1) vertical) shall be mulched at the
rate of one hundred (100) pounds per one thousand (1,000)
square feet when seeded.
(13) Ground adjoining project sites (lots) shall be provided
with protection from accelerated and increased surface water,
silt from erosion, and any other consequences of erosion.
Runoff water from developed areas (parking lots, paved sites,
and buildings) above the area to be developed shall be
directed to diversions, detention basins, concrete gutters,
and/or underground outlet systems. Sufficiently anchored
straw bales may be substituted with the approval of the city
engineer.
(14) Development along natural watercourses shall have a
minimum fifty -foot general maintenance and drainage easement.
The easement shall be measured from the top of the existing
stream bank. Development shall not encroach on said fifty -
foot easement. The watercourse shall be maintained by and be
made the responsibility of the appropriate legal entity.
Permanent vegetation should be left intact. Variances will
include designed stream bank erosion control measures and
shall be approved by the city engineer. FEMA guidelines shall
be followed where applicable regarding site development in
floodplains.
(15 ) All lots shall be seeded and mulched or sodded, with a
density of at least seventy (70) percent vegetative cover
over the entire disturbed area before the certificate of
occupancy shall be issued.
(16) BMPs for post construction water quality improvement
are to be used when feasible. Designers are encouraged to
25
implement cooperative use of required landscaping areas and
stormwater quality measures. Examples of these BMPs are
located in the city standards and specifications.
is hereby repealed in its entirety and a new Section 23-8
entitled "General design requirements for stormwater management
plan and SWPPP", is hereby enacted in lieu thereof, in words and
figures, to read as follows, to -wit:
Sec. 23-8. - General design requirements for stormwater
management plan and SWPPP.
(1) A stormwater management system shall be provided for
protecting lots, roads, streets and buildings in the project
area from the potential adverse impacts of stormwater runoff.
Streets, blocks, depths of lots, parks and other public
grounds, and ultimate land usage shall be determined, located
and laid out in such a manner as to reduce the velocity of
overland flow and allow the maximum opportunity for
infiltration of stormwaters into the ground, and to preserve
and utilize natural streams, channels and detention basins,
and wherever possible, to include streams and floodplains
within parks or other public grounds. The elements of the
stormwater management plan should protect area waterways from
pollutants carried by the stormwater runoff.
(2) The maximum allowable release rate of stormwater after
development shall be as follows:
(a) The rate shall not exceed the before -development rate
for a ten-year frequency storm of 30 minute duration.
(b) The twenty -five-year storm shall have the release rate
of a ten-year frequency storm of 30 minute duration.
(c) The total drainage area must be used in calculating the
allowable release rate. The required storage volume will
be based on the project area only, with extraneous flows
from upland areas being pass-through flow or discharged
via overflow spillway or other devices.
(d) The runoff from a one -inch rain event shall be managed
for water quality improvement by means of filtration and
flow control. Details for this stormwater management
element are located in the City of Cape Girardeau's
Standard Specifications and Drawings.
(3) The increased stormwater runoff
development shall be detained
detention basins or by other
minimum volume of storage shall
26
resulting from the proposed
on-site by appropriate
acceptable techniques. The
be sufficient to store the
volume of the difference between ten-year 30 minute storm
under undeveloped conditions and the twenty-five year 30
minute storm under developed conditions. Control devices
shall limit the discharge from storage to a rate no greater
than that prescribed by this chapter. Downstream property,
watercourses, channels or conduits shall not receive
stormwater runoff from proposed development at a higher peak
flow rate than that which existed prior to the development.
Detention/retention areas should at a minimum filter the
stormwater runoff. When possible, filtration and/or
infiltration practices should be incorporated into the site
design.
(a) Where a development site has more than one (1)
watershed, the runoff water shall be controlled within
each watershed. Exemption from this requirement must be
approved by the city manager or his designee. With a
request for this exemption, the developer will be required
to present information and/or documentation establishing
conclusively that no adverse impacts would occur to
adjoining or downstream properties from uncontrolled
runoff in a particular watershed area of the development
site.
(4) Generally acceptable locations of the stormwater runoff
channels in the design of the project area may include the
following:
(a) In a depressed median of a double roadway, street or
parkway, provided the median is wide enough to permit
required roadway shoulders.
(b) Centered on the rear lot lines in a block, or entirely
within the rear yards of a single row of lots or parcels,
provided that in either case the lots are deep enough to
permit side slopes in the runoff channel and a building
site of the elevation required by other sections of this
chapter.
(c) In a depressed area along roadway, street or parkway,
provided the area is wide enough to permit side slopes as
required in other sections of this chapter.
(d) Landscaped areas may be designed for use as part of the
stormwater management system.
(e) Alternative systems such as curb and gutter and storm
sewers that discharge into an appropriate detention basin
may be incorporated into the stormwater management plan.
(f) The smaller, uppermost reaches of drainage channels and
swales forming the natural drainage system near a
27
watershed divide may be relocated or eliminated and
incorporated into the planned system of storm sewers and
open channels designed consistent with the requirements of
this chapter.
(5) A continuous easement may be provided abutting rear lot
lines as shown in the stormwater management plan within which
utility lines and open drainage facilities may be located and
maintained, but on which no accessory buildings may be
constructed. The utility drainage easement shall be at least
twenty (20) feet wide. Within the area so designed for the
passage or storage of waters, no structure may be erected, no
fences, shrubbery or trees planted, or changes made to the
prescribed grades and contours of the specified floodwater or
stormwater runoff channels.
(6) All storm sewer outfalls shall be so designed, by reason of
elevation of the invert, by a flap gate or by other features,
that when the receiving stream is in full flood, the storm
sewers will continue to drain the areas they are designed to
serve unless the provision is made for sewer backups into
planned storage locations.
(7) All sanitary sewer manholes constructed in a floodplain, in
a street designed for detention, or in an area designed for
the storage or passage of floodwater or stormwater, shall be
provided with either a watertight bolted manhole cover, a
watertight concealed pick -hole cover, or be constructed with
a rim elevation at or above the high water elevation of the
100 -year flood or the high water elevation of the design
storm, whichever is applicable to the specific area.
(8) Projects that are to be developed in phases will normally
require the submission of a master plan of the applicant's
contiguous land holdings. Applications for individual project
phases may be considered only when the phases are totally
independent of, or make sufficient provisions for, adjacent
lands.
(9) All excavations, grading or filling shall have a finished
grade not to exceed a 3:1 (three (3) horizontal to one (1)
vertical) slope. Steeper grades may be approved by the city
engineer if the excavation is through rock or the excavation
or fill is protected (a designed head wall or toe wall may be
required) .
(10) Grading plans for sites that exceed one (1) acre shall
provide for erosion control and for sediment controls, or
debris basins, silt traps or filters, staked straw bales, a
combination of these measures or other measures approved by
the city engineer to remove sediment from runoff waters.
Temporary sediment control measures (structural) shall be
maintained until vegetative cover is established at a
sufficient density to provide erosion control on the site.
(11) Where natural vegetation is removed during grading,
vegetation shall be reestablished in such a density as to
prevent erosion. Permanent type grasses shall be established
as soon as possible during the next seeding period after
grading has been completed. Trees, plants and vegetative
cover should be of native species, when possible. Reference
the city development manual and other city ordinances for
examples.
(12) When grading operations are completed or suspended for
more than fourteen (14) days between permanent grass seeding
periods, temporary cover shall be provided. All finished
grades (areas not to be disturbed by future improvements) 4:1
slopes or steeper shall be sodded, hydro seeded, or have
erosion control fabric installed; slopes less than 4:1 (four
(4) horizontal to one (1) vertical) shall be mulched at the
rate of one hundred (100) pounds per one thousand (1,000)
square feet when seeded.
(13) Ground adjoining project sites (lots) shall be provided
with protection from accelerated and increased surface water,
silt from erosion, and any other consequences of erosion.
Runoff water from developed areas (parking lots, paved sites,
and buildings) above the area to be developed shall be
directed to diversions, detention basins, concrete gutters,
and/or underground outlet systems. Sufficiently anchored
straw bales may be substituted with the approval of the city
engineer.
(14) Development along natural watercourses shall have a
minimum fifty -foot general maintenance and drainage easement.
The easement shall be measured from the top of the existing
stream bank. Development shall not encroach on said fifty -
foot easement. The watercourse shall be maintained by and be
made the responsibility of the appropriate legal entity.
Permanent vegetation should be left intact. Variances will
include designed stream bank erosion control measures and
shall be approved by the city engineer. FEMA guidelines shall
be followed where applicable regarding site development in
floodplains.
(15) All lots shall be seeded and mulched or sodded, with a
density of at least seventy (70) percent vegetative cover
over the entire disturbed area before the certificate of
occupancy shall be issued.
29
(16) BMPs for post construction water quality improvement are
to be used when feasible. Designers are encouraged to
implement cooperative use of required landscaping areas and
stormwater quality measures. Examples of these BMPs are
located in the city standards and specifications.
ARTICLE 4. Section 23-9 of the Code of Ordinances of the
City of Cape Girardeau, Missouri, entitled "Hydraulic design
considerations", reading as follows:
Sec. 23-9. - Hydraulic design considerations.
(1) Stormwater systems will be designed with sufficient
hydraulic capacity as a minimum for the following frequencies
and durations:
Type of
Facility
(a) I Detention basins
(b) I Primary drainage systems
(c) I Bridges
(d) Secondary drainage systems, i.e., crossdrains and ditches for internal subdivision
drainage
Design
Frequency
25 -year
25 -year
50 -year
15 -year
(2) The city manager or his designee may require alternative
designs or features to reduce the cost of long-term
maintenance.
(3) In critical areas, the city manager or his designee may
require additional hydraulic capacity above the minimums set
forth above, up to the 100 -year frequency design.
(4) The city manager or his designee may require a developer
to improve the stormwater facilities immediately upstream or
downstream of a development if adverse impacts from said
development are foreseen. The developer will be responsible
for all costs associated with the improvements.
is hereby repealed in its entirety and a new Section 23-9
entitled "Hydraulic design considerations", is hereby enacted in
30
lieu thereof, in words and figures, to read as follows, to -wit:
Sec. 23-9. Hydraulic design considerations.
(1) Stormwater systems will be designed with sufficient
hydraulic capacity as a minimum for the following frequencies
and durations:
(2) The city manager or his designee may require alternative
designs or features to reduce the cost of long-term
maintenance.
(3) In critical areas, the city manager or his designee may
require additional hydraulic capacity above the minimums set
forth above, up to the 100 -year frequency design.
(4) The city manager or his designee may require a developer
to improve the stormwater facilities immediately upstream or
downstream of a development if adverse impacts from said
development are foreseen. The developer will be responsible
for all costs associated with the improvements.
ARTICLE 5. Section 23-10 of the Code of Ordinances of the
City of Cape Girardeau, Missouri, entitled "Stormwater
management system design requirements", reading as follows.
Sec 23-10. Stormwater management system design
requirements.
(1) Calculations. The design of the stormwater system shall
be in accordance with the City of Cape Girardeau's Storm
Drainage Design Manual (if available). If not available, the
31
Type of
Design
Facility
Frequency
(a)
Detention basins
25 -year
(b)
Primary drainage systems
25 -year
(c)
Bridges
50 -year
Secondary drainage systems, i.e., crossdrains and
10 -year
(d)
ditches for internal subdivision drainage
30
min
(2) The city manager or his designee may require alternative
designs or features to reduce the cost of long-term
maintenance.
(3) In critical areas, the city manager or his designee may
require additional hydraulic capacity above the minimums set
forth above, up to the 100 -year frequency design.
(4) The city manager or his designee may require a developer
to improve the stormwater facilities immediately upstream or
downstream of a development if adverse impacts from said
development are foreseen. The developer will be responsible
for all costs associated with the improvements.
ARTICLE 5. Section 23-10 of the Code of Ordinances of the
City of Cape Girardeau, Missouri, entitled "Stormwater
management system design requirements", reading as follows.
Sec 23-10. Stormwater management system design
requirements.
(1) Calculations. The design of the stormwater system shall
be in accordance with the City of Cape Girardeau's Storm
Drainage Design Manual (if available). If not available, the
31
development calculations shall be based on the minimum of one
(1) fifteen -minute rainfall using the following:
Watershed
Area
Method
(acres)
0-25
Rational (See Note 1)
>25
Technical Release 55 (TR -55) (See Note 2)
Note 1: Rational Method shall be as identified in Missouri
Department of Transportation Design Manual Chapter IX -
Hydraulics and Drainage current edition.
Note 2: Technical Release 55 (TR -55) shall be as identified
in the NRCS Urban Hydrology for Small Water Sheds.
(2) Open channels.
(a) Open channels, natural or improved, may be placed at the
rear or side of properties upon approval of the city
engineer where the design provides adequate protection to
the existing and future property and structures. Such
protection shall be through the provision of a fifty-year
floodplain setback and a minimum distance from the toe of
bank to the setback of fifty (50) feet. This drainage
setback line shall be shown on the final plat. Permanent
vegetation, existing ground elevation, and grades within
the fifty -foot setback area shall be left intact and
undisturbed on channels with watersheds of one hundred
(100) acres or more unless modification is approved in
writing by the director or his designee.
(b) Area inlets shall be required behind the curbs to
intercept overland flows greater than one (1) cfs to
prevent flows from crossing sidewalks and/or curbs.
(3) Inlets and junction boxes. Inlets, junctions boxes and
inlet spacing shall be per the city's standard details and as
approved by the city engineer. When locating inlets in sump
locations consideration must be made with respect to the
major drainage system. A 100 -year design event shall not
cause buildings to flood in the event that a single inlet
becomes blocked. In new developments the 100 -year design
storm elevation shall be mapped on the final plat as a
32
building setback. Overland relief to another inlet or surface
channel shall be provided to protect property.
(4) Enclosed systems.
(a) The outlet of an enclosed system shall have sufficient
energy dissipation provided to negate the increases posed
by development as approved by the city engineer.
(b) Building gutter drainage systems may not be discharged
directly into the city's enclosed system.
(c) If development plans call for the enclosure of an
existing, natural drainageway which carries greater than
fifty (50) cfs during the design storm event, the
enclosure shall be sized for a fifty-year twenty -minute
storm event. Upstream inundation shall be checked. Where
inundation extends beyond the site property line and
exceeds the design water surface elevation of the natural
drainway/channel, a backwater ponding easement from the
affected off-site property owner(s) shall be required
prior to final plan approval. A reduction in the design
storm requirement may be granted by the city engineer when
existing off-site, downstream storm sewer would be smaller
than the required on-site, upstream sewer and the
downstream storm sewer are not designed to intercept/pass
the fifty-year twenty -minute storm event.
(5) Detention design criteria. Detention in the overall
system, including swales, lakes, canals, greenways, etc.,
shall be provided as follows.
(6) General.
(a) Storage volumes. The minimum volume of storage provided
in detention basins, together with such storage as may be
authorized in other on-site facilities, shall be
sufficient to store the volume of the difference between
the fifteen (15) year storm under undeveloped conditions
and the twenty-five (25) year storm under developed
conditions.
(b) Outlet control structures. Outlet control structures
shall be designed to operate simply and automatically.
They will limit discharges into existing or planned
downstream channels or conduits so as not to exceed
predetermined maximum authorized peak flow rates.
(c) Release rate. A release rate shall be calculated for a
two-, ten-, or twenty -five-year storm for the proposed
development in the condition prior to the proposed
development.
33
(d) Emergency spillway. Emergency overflow facilities must
be provided in all instances so that stored waters will
not exceed the safe capacity of the basin. At a minimum,
the emergency spillway must be able to pass without damage
the 100 -year storm.
(e) Appearance. Designs should result in aesthetically
pleasing configurations which will enhance public
acceptability.
(7) Dry -detention facilities.
(a) Perimeter maintenance easements of twenty (20) feet
(minimum) width at slopes no steeper than three to one
(3:1) (horizontal to vertical) shall be provided.
(b) Side slopes of the facility shall not be steeper than
three to one (3:1) (horizontal to vertical).
(c) Provisions must be incorporated to facilitate complete
interior drainage to dry bottom basins, to include the
provision of natural grades to outlet structures,
longitudinal and transverse grades to perimeter drainage
facilities, or the installation of subsurface drains.
(d) Multipurpose features may be designed to serve secondary
purposes for recreation, open space or other types of use
which will not be adversely affected by occasional or
intermittent flooding.
(e) In no case shall the limits of maximum ponding elevation
of a dry -detention facility within two (2) feet vertically
below the lowest sill elevation be closer than twenty-five
(25) feet horizontally from any building. The entire
reservoir area shall be seeded, fertilized and mulched,
sodded or paved.
(f) Fully paved low flow channels are prohibited. The flow
channel for low flow events shall be reinforced turf or
open sectioned pavers with grass or aggregate to allow
filtering of the stormwater and to support mowing
equipment. Other methods may be used as approved.
(8) Wet -detention facilities.
(a) Perimeter maintenance and operation easements of twenty
(20) feet (minimum preferable) width at slopes no steeper
than three to one (3:1) (horizontal to vertical) shall be
provided.
(b) Control elevations should be no higher than two and one-
half (21-i�) feet below the minimum road centerline elevation
in the area served by the control device in order to
34
protect the road subgrade when structures are constructed
near roads.
(c) Side slopes shall not be steeper than three to one (3:1)
(horizontal to vertical) out to a depth of two (2) feet
below the control elevation, then as steep as soils
stability will allow.
(d) If fish are to be used to help keep the basin clean, at
least one-quarter (1-4) of an area of the permanent pool
must be a minimum depth of ten (10) feet.
(e) For emergency purposes, cleaning or shoreline
maintenance, facilities shall be provided or plans
prepared for the use of auxiliary equipment to permit
emptying and drainage.
(f) In no case shall the limits of maximum ponding elevation
of a wet -detention facility within two (2) feet vertically
below the lowest sill elevation be closer than thirty (30)
feet horizontally from the lowest sill elevation of any
building.
(9) Underground storage. All or a portion of the detention
storage may also be provided for in underground facilities,
as long as all applicable requirements of this chapter are
met. Details of such designs are to include type of facility,
depth and volume of storage, details of inlet and outlet
devices and locations, emergency overflow provisions, and
measures to be used for surface water and groundwater
pollution control.
(10) Design alternatives. The above listing of design
criteria is not intended to preclude the use of other known
state -of -the art methods and available best management
practices and should not be construed as a mechanism to
discourage innovative design concepts.
(11) Developments adjoining a floodplain. Where a
development adjoins or encompasses a portion of a floodplain
for a 100 -year flood, the following shall apply:
(a) The applicant shall show the floodplain and floodway on
the stormwater management plan.
(b) The applicant shall include in the stormwater management
plan all other plans, plats, specifications, etc.,
required by federal, state, county and/or municipal laws
or regulations detailing such provisions or restrictions
as are necessary to comply with the following:
1. All applicable zoning and subdivision requirements.
35
2. All applicable building code requirements.
3. All requirements of other federal, state or local
agencies exercising jurisdiction over the area.
(12) Channel flow The applicant shall not alter any channel
in such a way that would prohibit any section of the channel
from conveying, in its post -development state, the same
amount of flow at the same or lower maximum water elevation
that it conveyed in its predevelopment state.
(13) Modifications of channel. The applicant shall furnish,
for the city manager's or his designee's review and approval,
the following information pertaining to proposed channel
modifications:
(a) Typical cross sections of the existing and proposed
channel.
(b) Plan view of the channel showing the location of
existing constructions, obstructions and other nontypical
areas.
(c) Hydrographs and/or flood routing calculations and
backwater curve profiles of the proposed waterway
corresponding to a storm recurrence interval of one
hundred (100) years.
(d) Engineering evaluation of all potential increases in
flood hazards to the adjacent upstream or downstream
private or public lands and facilities located thereon,
showing provisions for eliminating any and all adverse
impacts on such land and facilities at no public cost.
(e) Minimum finished floor elevations which shall be set at
or above the maximum water surface elevation as determined
by either or both of the following:
1. "Flood Insurance Rate Map" published by the Federal
Emergency Management Agency.
2. Backwater curve profiles of the proposed waterway due
to a 100 -year storm recurrence interval.
(f) Designation on the final plan of all areas reserved for
flood routing, detention or storage, together with the
required wording pertaining to restrictions, dedications
and maintenance responsibilities of such areas.
(14) Detention storage. If detention storage is provided
within a floodplain, only the net increase in storage volume
above that which naturally existed on the floodplain shall be
credited to the development. No credit will be granted for
36
volumes below the elevation of the regulatory flood at that
location unless compensatory storage is also provided.
(15) Verification of adequacy. Analysis of all elements of
design is to be verified by the engineer of record submitting
the plan. The following outline is provided to ascertain that
certain critical elements are in workable compliance with the
aims of this chapter. For projects less than fifty (50) acres
in area there is no need for submittal of routing
calculations or tabulated proof of adequacy of tributary
runoff for detention; however, it is recommended that
verification be made of:
(a) Volume of detention for the total project.
(b) Tributary (Q) peak runoff to basin.
(c) Balanced maximum outflow rate from the low -flow
structure.
(d) Ratios of inflow to outflow rates.
(e) Sizing of the overflow facilities.
(f) Stability of detention dikes.
(g) Safety features.
(h) Maintenance features.
For projects of fifty (50) acres or greater but less than two
hundred (200), routing calculations shall be submitted in
legible tabulated form. Proof of adequacy of volume of detention
and sizing computations for low -flow structure shall also be
submitted. Features of stability and safety may also need to be
documented if the scope of the project requires special
attention in this area of design.
Projects over two hundred (200) acres in area shall provide
documented verification of adequacy according to scope and
complexity of design.
(16) Installation of stormwater runoff control measures.
Positive stormwater runoff control shall be provided for
during development. Stormwater management plans shall include
a schedule for the installation, construction or modification
of all drainage facilities. Erosion control measures and a
schedule for their installation shall be shown on the
stormwater management plan. Installation of drainage
facilities and erosion control measures shall proceed as
scheduled in the approved stormwater management plan.
(17) Erosion and sedimentation control criteria. The best
management practices to control the occurrence of erosion and
37
sedimentation are to be incorporated into the plan for the
time land is disturbed by development activity. Permanent
controls and practices shall also be identified where they
are necessary to control an ongoing potential for erosion and
sedimentation. Types of best management practices include,
but are not limited to:
(a) Use of state approved standard specifications of the
city.
(b) Tree, topsoil and vegetative cover preservation and
restoration.
(c) Surface stabilization with various natural or manmade
materials.
(d) Runoff control measures that address quantity and
quality of runoff waters such as berms, dikes, sediment
traps, filtration and infiltration methods and barriers.
(e) Inlet and outlet protection.
(f) Stream bank protection.
(g) Scheduling of development activities and protection
measures for minimal impact.
(h) For post construction water quality controls, landscaped
areas may be used.
is hereby repealed in its entirety and a new Section 23-10
entitled "Stormwater management system design requirements", is
hereby enacted in lieu thereof, in words and figures, to read as
follows, to -wit:
Sec. 23-10. - Stormwater management system design
requirements.
(1) Calculations. The design of the stormwater system shall
be in accordance with the City of Cape Girardeau's Storm
Drainage Design Manual (if available). If not available, the
development calculations shall be based on the minimum of one
(1) fifteen -minute rainfall using the following:
Watershed
Area Method
(acres)
0-25 Rational (See Note 1)
>25 Technical Release 55 (TR -55) (See Note 2)
Note l: Rational Method shall be as identified in Missouri
Department of Transportation Design Manual Chapter IX -
Hydraulics and Drainage current edition.
Note 2: Technical Release 55 (TR -55) shall be as identified
in the NRCS Urban Hydrology for Small Water Sheds.
(2) Open channels.
(a) Open channels, natural or improved, may be placed at the
rear or side of properties upon approval of the city
engineer where the design provides adequate protection to
the existing and future property and structures. Such
protection shall be through the provision of a fifty-year
floodplain setback and a minimum distance from the toe of
bank to the setback of fifty (50) feet. This drainage
setback line shall be shown on the final plat. Permanent
vegetation, existing ground elevation, and grades within
the fifty -foot setback area shall be left intact and
undisturbed on channels with watersheds of one hundred
(100) acres or more unless modification is approved in
writing by the director or his designee.
(b) Area inlets shall be required behind the curbs to
intercept overland flows greater than one (1) cfs to
prevent flows from crossing sidewalks and/or curbs.
(3) Inlets and junction boxes. Inlets, junctions boxes and
inlet spacing shall be per the city's standard details and as
approved by the city engineer. When locating inlets in sump
locations consideration must be made with respect to the
major drainage system. A 100 -year 30 minute storm design
event shall not cause buildings to flood in the event that a
single inlet becomes blocked. In new developments the 100 -
year 30 minute design storm elevation shall be mapped on the
final plat as a building setback. Overland relief to another
inlet or surface channel shall be provided to protect
property.
(4) Enclosed systems.
(a) The outlet of an enclosed system shall have sufficient
energy dissipation provided to negate the increases posed
by development as approved by the city engineer.
(b) Building gutter drainage systems may not be discharged
directly into the city's enclosed system.
39
(c) If development plans call for the enclosure of an
existing, natural drainageway which carries greater than
fifty (50) cfs during the design storm event, the
enclosure shall be sized for a fifty-year 30 minute storm
event. Upstream inundation shall be checked. Where
inundation extends beyond the site property line and
exceeds the design water surface elevation of the natural
drainway/channel, a backwater ponding easement from the
affected off-site property owner(s) shall be required
prior to final plan approval. A reduction in the design
storm requirement may be granted by the city engineer when
existing off-site, downstream storm sewer would be smaller
than the required on-site, upstream sewer and the
downstream storm sewer are not designed to intercept/pass
the fifty-year twenty -minute storm event.
(5) Detention design criteria. Detention in the overall system,
including swales, lakes, canals, greenways, etc., shall be
provided as follows.
(6) General.
(a) Storage volumes. The minimum volume of storage provided
in detention basins, together with such storage as may be
authorized in other on-site facilities, shall be
sufficient to store the volume of the difference between
the ten-year 30 minute storm under undeveloped conditions
and the twenty-five year 30 minute storm under developed
conditions.
(b) Outlet control structures. Outlet control structures
shall be designed to operate simply and automatically.
They will limit discharges into existing or planned
downstream channels or conduits so as not to exceed
predetermined maximum authorized peak flow rates.
(c) Release rate. A release rate shall be calculated for a
ten-year 30 minute storm for the proposed development in
the condition prior to the proposed development.
(d) Emergency spillway. Emergency overflow facilities must
be provided in all instances so that stored waters will
not exceed the safe capacity of the basin. At a minimum,
the emergency spillway must be able to pass without damage
the 100 -year 30 minute storm.
(e) Appearance. Designs should result in aesthetically
pleasing configurations which will enhance public
acceptability.
(7) Dry -detention facilities.
MI
(a) Perimeter maintenance easements of twenty (20) feet
(minimum) width at slopes no steeper than three to one
(3:1) (horizontal to vertical) shall be provided.
(b) Side slopes of the facility shall not be steeper than
three to one (3:1) (horizontal to vertical).
(c) Provisions must be incorporated to facilitate complete
interior drainage to dry bottom basins, to include the
provision of natural grades to outlet structures,
longitudinal and transverse grades to perimeter drainage
facilities, or the installation of subsurface drains.
(d) Multipurpose features may be designed to serve secondary
purposes for recreation, open space or other types of use
which will not be adversely affected by occasional or
intermittent flooding.
(e) In no case shall the limits of maximum ponding elevation
of a dry -detention facility within two (2) feet vertically
below the lowest sill elevation be closer than twenty-five
(25) feet horizontally from any building. The entire
reservoir area shall be seeded, fertilized and mulched,
sodded or paved.
(f) Fully paved low flow channels are prohibited. The flow
channel for low flow events shall be reinforced turf or
open sectioned pavers with grass or aggregate to allow
filtering of the stormwater and to support mowing
equipment. Other methods may be used as approved.
(8) Wet -detention facilities.
(a) Perimeter maintenance and operation easements of twenty
(20) feet (minimum preferable) width at slopes no steeper
than three to one (3:1) (horizontal to vertical) shall be
provided.
(b) Control elevations should be no higher than two and one-
half (21-�) feet below the minimum road centerline elevation
in the area served by the control device in order to
protect the road subgrade when structures are constructed
near roads.
(c) Side slopes shall not be steeper than three to one (3:1)
(horizontal to vertical) out to a depth of two (2) feet
below the control elevation, then as steep as soils
stability will allow.
(d) If fish are to be used to help keep the basin clean, at
least one-quarter (1-4) of an area of the permanent pool
must be a minimum depth of ten (10) feet.
41
(e) For emergency purposes, cleaning or shoreline
maintenance, facilities shall be provided or plans
prepared for the use of auxiliary equipment to permit
emptying and drainage.
(f) In no case shall the limits of maximum ponding elevation
of a wet -detention facility within two (2) feet vertically
below the lowest sill elevation be closer than thirty (30)
feet horizontally from the lowest sill elevation of any
building.
(9) Underground storage. All or a portion of the detention
storage may also be provided for in underground facilities,
as long as all applicable requirements of this chapter are
met. Details of such designs are to include type of facility,
depth and volume of storage, details of inlet and outlet
devices and locations, emergency overflow provisions, and
measures to be used for surface water and groundwater
pollution control.
(10) Design alternatives. The above listing of design criteria
is not intended to preclude the use of other known state -of -
the art methods and available best management practices and
should not be construed as a mechanism to discourage
innovative design concepts.
(l 1) Developments adjoining a floodplain. Where a development
adjoins or encompasses a portion of a floodplain for a 100 -
year flood, the following shall apply:
(a) The applicant shall show the floodplain and floodway on
the stormwater management plan.
(b) The applicant shall include in the stormwater management
plan all other plans, plats, specifications, etc.,
required by federal, state, county and/or municipal laws
or regulations detailing such provisions or restrictions
as are necessary to comply with the following:
1. All applicable zoning and subdivision requirements.
2. All applicable building code requirements.
3. All requirements of other federal, state or local
agencies exercising jurisdiction over the area.
(12) Channel flow The applicant shall not alter any channel in
such a way that would prohibit any section of the channel
from conveying, in its post -development state, the same
amount of flow at the same or lower maximum water elevation
that it conveyed in its predevelopment state.
MM
(13) Modifications of channel. The applicant shall furnish, for
the city manager's or his designee's review and approval, the
following information pertaining to proposed channel
modifications:
(a) Typical cross sections of the existing and proposed
channel.
(b) Plan view of the channel showing the location of
existing constructions, obstructions and other nontypical
areas.
(c) Hydrographs and/or flood routing calculations and
backwater curve profiles of the proposed waterway
corresponding to a 100 -year 30 minute storm.
(d) Engineering evaluation of all potential increases in
flood hazards to the adjacent upstream or downstream
private or public lands and facilities located thereon,
showing provisions for eliminating any and all adverse
impacts on such land and facilities at no public cost.
(e) Minimum finished floor elevations which shall be set at
or above the maximum water surface elevation as determined
by either or both of the following:
1. "Flood Insurance Rate Map" published by the Federal
Emergency Management Agency.
2. Backwater curve profiles of the proposed waterway due
to a 100 -year 30 minute storm recurrence interval.
(f) Designation on the final plan of all areas reserved for
flood routing, detention or storage, together with the
required wording pertaining to restrictions, dedications
and maintenance responsibilities of such areas.
(14) Detention storage. If detention storage is provided within
a floodplain, only the net increase in storage volume above
that which naturally existed on the floodplain shall be
credited to the development. No credit will be granted for
volumes below the elevation of the regulatory flood at that
location unless compensatory storage is also provided.
(15) Verification of adequacy. Analysis of all elements of
design is to be verified by the engineer of record submitting
the plan. The following outline is provided to ascertain that
certain critical elements are in workable compliance with the
aims of this chapter. For projects less than fifty (50) acres
in area there is no need for submittal of routing
calculations or tabulated proof of adequacy of tributary
runoff for detention; however, it is recommended that
verification be made of:
43
(a) Volume of detention for the total project.
(b) Tributary (Q) peak runoff to basin.
(c) Balanced maximum outflow rate from the low -flow
structure.
(d) Ratios of inflow to outflow rates.
(e) Sizing of the overflow facilities.
(f) Stability of detention dikes.
(g) Safety features.
(h) Maintenance features.
For projects of fifty (50) acres or greater but less than two
hundred (200), routing calculations shall be submitted in
legible tabulated form. Proof of adequacy of volume of detention
and sizing computations for low -flow structure shall also be
submitted. Features of stability and safety may also need to be
documented if the scope of the project requires special
attention in this area of design.
Projects over two hundred (200) acres in area shall provide
documented verification of adequacy according to scope and
complexity of design.
(16) Installation of stormwater runoff control measures.
Positive stormwater runoff control shall be provided for
during development. Stormwater management plans shall include
a schedule for the installation, construction or modification
of all drainage facilities. Erosion control measures and a
schedule for their installation shall be shown on the
stormwater management plan. Installation of drainage
facilities and erosion control measures shall proceed as
scheduled in the approved stormwater management plan.
(17) Erosion and sedimentation control criteria. The best
management practices to control the occurrence of erosion and
sedimentation are to be incorporated into the plan for the
time land is disturbed by development activity. Permanent
controls and practices shall also be identified where they
are necessary to control an ongoing potential for erosion and
sedimentation. Types of best management practices include,
but are not limited to:
(a) Use of state approved standard specifications of the
city.
(b) Tree, topsoil and vegetative cover preservation and
restoration.
ME
(c) Surface stabilization with various natural or manmade
materials .
(d) Runoff control measures that address quantity and
quality of runoff waters such as berms, dikes, sediment
traps, filtration and infiltration methods and barriers .
(e) Inlet and outlet protection.
(f) Stream bank protection.
(g) Scheduling of development activities and protection
measures for minimal impact .
(h) For post construction water quality controls, landscaped
areas may be used.
ARTICLE 6. It is the intention of the governing body and it
is hereby ordained that the provisions of this ordinance shall
become and be made a part of the Code of Ordinances of the City
of Cape Girardeau, Missouri, and the sections of this Code may
be renumbered to accomplish such intention.
ARTICLE 7 . This ordinance shall take effect and be in force
from and after ten days after its final passage and approval .
PASSED AND APPROVED THIS
1i, H
`
DAY OF ___),,,ALA , 2018 .
//
Bob F. , ayor
ATTEST: .,
� A
1
truce Tayl# ieputy City Clerk ® �
i '' f 1., /1/4_ t;1
TIME� VIIIIO �
.� ,-1
I,II kgl . y`tY1-
45
Language to be added is in yellow hi -light.
Language to be deleted is in Fed strikethrough.
Chapter 23 - STORMWATER MANAGEMENT REGULATIONS"'
Footnotes:
--- (1) ---
Editor's note— Article 1 of Ord. No. 4253, adopted Aug. 15, 2011, repealed ch. 23 in its entirety and
enacted similar provisions to read as herein set out. Former ch. 23 derived from Ord. No. 675, adopted
March 6, 1989; Ord. No. 798, adopted Dec. 18, 1989; Ord. No. 1240, adopted Sept. 21, 1992; Ord. No.
2310, adopted Jan. 5, 1998; Ord. No. 2827, adopted Dec. 18, 2000; and Ord. No. 3753, adopted Nov. 6,
2006.
Cross reference— Floodplain management regulations, ch. 12; streets and sidewalks, ch. 24; urban
redevelopment, ch. 28; water and sewers, ch. 29; public works department, § 2-54.
Sec. 23-1. - Definitions.
As used in this chapter, the following definitions apply:
Adverse impact. Any modifications, alterations, or effects on a feature or characteristic of surface
waters including their quality, quantity, hydrodynamics, surface area, species composition, living
resources, aesthetics or usefulness for human or natural uses which are or may potentially be harmful or
injurious to human health, welfare, safety or property, to biological productivity, diversity, or stability, or
which unreasonably interfere with the enjoyment of life or property, including outdoor recreation. The term
includes secondary and cumulative, as well as direct impacts.
Applicant. The record owner, or his authorized representative, of a tract of land that is the site of
development, or development activity within the scope of this chapter.
Base flood elevation. The elevation at any location delineating high waters having a one (1) percent
probability of being equaled or exceeded in any given year, as determined by FEMA and described on the
flood insurance rate maps (FIRMs).
Best management practice (BMP). Any physical, chemical or managerial practice that reduces soil
erosion or reduces the amount of sediment or other pollutants discharging to or potentially discharging to
the MS4. There are structural and nonstructural BMPs.
Building. Any structure built for the support, shelter or enclosure of persons, animals, chattels or
movable property of any kind.
Capacity of a storm drainage facility. The maximum ability of a storm drainage facility to convey,
detain or retain stormwater flows without causing substantial damage to public or private property, and in
the case of a pipe, without surcharging.
Channel. A natural or artificial open watercourse with definite bed and banks which periodically or
continuously contains moving water or which forms a connecting link between two (2) bodies of water.
Clearing. The act of removing trees or vegetation from a tract of land and disturbing soil conditions.
Conduit. Any channel, pipe, sewer or culvert used for the conveyance or movement of water,
whether open or closed.
Control device. An element of a discharge structure which allows the gradual release of water under
controlled conditions.
Control elevation. The design elevation of a discharge structure at which, or below which, water is
contained behind the structure.
CPESC. Certified professional in erosion and sediment control.
Detention. The delay of storm runoff prior to discharge into receiving waters.
Detention basin. A facility constructed or modified to restrict the discharge of stormwater to a
prescribed maximum rate, and to concurrently detain the excess waters that accumulate behind the
outlet. A wet bottom detention basin is a structure designed to retain a permanent pool of water after
having provided its planned detention of runoff during a storm event. A dry bottom detention basin is
designed to be completely dewatered after having provided its planned detention of runoff during a storm
event.
Detention storage. The temporary detaining or storage of stormwater in storage basins, or rooftops,
in streets, parking lots, school yards, parks, open space, or other areas under predetermined and
controlled conditions, with the rate of drainage therefrom regulated by appropriately installed devices.
Detention volume. The volume of water equal to the difference between the control elevation of a
discharge structure and the maximum level at which water can be accumulated prior to discharge times
the average area of open surface storage (between the control elevation and maximum level) behind the
discharge structure.
Developer. Any individual, firm, corporation, association, partnership, or other entity involved in
commencing proceedings under this chapter to effect the development of land for himself or another.
Development or development activity. Any manmade change to improved or unimproved land,
including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving,
excavation, or drilling operation. Any subdivision of land as defined in the city's subdivision regulations,
excluding minor subdivisions.
Differential runoff. The difference in rate and volume of stormwater runoff from a parcel or project in
its undeveloped natural condition and its developed condition is known as the differential runoff.
Discharge. The rate of outflow of water from detention storage.
Discharge structure. A structural device, usually of concrete, metal, timber, etc., through which water
is discharged from a project to the receiving water.
Drainage area. The area from which water is carried off by a drainage system; a watershed or
catchment area.
Drainage easement. An easement for the sole purpose of allowing water to flow through it. The city
shall not be responsible for maintenance in a drainage easement.
Drainage and maintenance easement. An easement for the purpose of allowing water to flow
through it. The city shall be responsible for maintenance in a drainage and maintenance easement.
Drainage facility. An element in a drainage system which includes, but is not limited to, any of the
following: conduits and appurtenant features, canals, channels, detention basins, ditches, streams,
culverts, streets and pumping stations.
Drainage system. The surface or subsurface system which conveys water from or over the land,
including all watercourses, water bodies and wetlands (also referred to as the "stormwater management
system").
Easement. A grant by a property owner to the public, a corporation, or a person of the use of land for
a specific purpose.
Elevation. The height in feet above mean sea level according to National Geodetic Vertical Datum
(NGVD).
Emergency spillway. A saddle or low point facility located around the rim of a dammed impoundment
such as a detention or retention basin for providing an efficient and safe means of conveying the
maximum design flood discharge through the impoundment, without overtopping the dam.
Erosion. The wearing away of the land surface by the action of the wind, water, ice, gravity, or any
combination thereof.
Excess stormwater runoff. The volume and rate of flow of stormwater discharged from a drainage
area which is or will be in excess of that volume and rate which is specified in this chapter.
Filling. To place soil, rock, or other material over the natural topography of a site such that the
natural grade and/or elevation is altered.
Filtration Trench. An element of stormwater management that acts in the manner of a french drain.
It shall be a trench sized to the site requirements and filled with clean 2 inch minimum stone with no fines.
The air spaces in the stone allow the site stormwater runoff to filter through the trench to remove various
pollutants. The trench will have an outflow pipe a minimum of 6 inches from the bottom of the trench.
Floodplain. The special flood hazard land adjoining a watercourse, the surface elevation of which is
equal to or lower than the base flood elevation (the 100 -year flood), which is subject to periodic
inundation during floods.
Flood fringe. The higher portion of the floodplain, immediately adjacent to and on either side of the
floodway, occupied by quiescent or slow moving waters during floods.
Floodway. The channel of a watercourse and those portions of the adjoining floodplain which are
reasonably required to carry and discharge the base flood.
Grading. To level or smooth to a desired or horizontal gradient.
High-water elevation. The elevation of floodwaters of a flood of specified frequency or occurrence at
any given point.
Illicit discharge. Any direct or indirect discharge to the city's MS4 that is not composed entirely of
stormwater, unless exempt pursuant to city ordinance.
Impervious surface. A surface which has been compacted or covered with a layer of materials so
that it is highly resistant to infiltration of water. The term includes most conventionally surfaced streets,
roofs, sidewalks, parking lots and similar structures.
Improvement. A structure on, or other alteration of land on a given site, including, but not limited to,
grading, street paving, storm sewers, sanitary sewers and utilities.
MS4. Municipal separate storm sewer system.
Natural watercourse. A channel that is formed through the natural flow of stormwater runoff
influenced by area topography. The channel can carry a flow of water continuously or intermittently. Such
a channel can include but not be limited to swales, streams, creeks, gullies, ravines, or rivers of varying
depths and lengths. These channels carry a stream of water which flows along a naturally defined path,
usually with a bed and banks. It should, on casual examination, present the unmistakable evidence of the
frequent action of running water. If the flow of water occurs periodically from natural causes and reaches
a plainly defined channel of a permanent character, this is sufficient to establish a natural watercourse. A
natural watercourse may be altered through construction or development activities, and yet remain a
natural watercourse.
NOAA. National Oceanic and Atmospheric Administration.
Off-site detention basin. A feature or structure for temporarily storing excess stormwater originating
at two (2) or more sites having devices for controlling the rate of release of the stored water, and located
downstream of all sites where the runoff originates.
100 -year storm. A rainstorm of varying duration and intensity having a one (1) percent probability of
recurring in any one (1) year.
On-site detention basin. A feature or structure for temporarily storing excess stormwaters, having
devices for controlling the rate of release of the stored waters, and located within the sites where the
runoff originates.
Overflow elevation. A design elevation of a discharge structure at which point, or above which point,
water leaks out, or bleeds out, through a control device down to the control elevation.
Pass-through flow. Off-site water that is allowed to move through a detention basin without being
detained or included in the detention calculations.
Peak flow. The maximum rate of flow of water at a given point in a channel or conduit resulting from
a predetermined storm or flood.
Post -development conditions. Those conditions which are expected to exist, or do exist, after
alteration, resulting from human activity, of the natural topography, vegetation and rate, volume or
direction of surface or subsurface flow.
Predevelopment conditions. Those conditions which exist at a site prior to any alteration of the
natural topography, vegetation, flow rate, flow volume, or direction of surface or subsurface flow. In the
case of a site where development has occurred in the past the predevelopment condition shall be the
physical conditions of the site at the time of the application for the permit.
Primary drainage (water management) systems. Includes major waterways and appurtenant
structures or systems whose total tributary area from origin to outfall exceeds or equals fifty (50) acres.
Professional engineer or architect. An engineer or architect duly registered or otherwise authorized
by the state to practice engineering.
Project site. Any site where construction activity will result in land disturbance by means of filling,
clearing, excavating and/or grading.
Rational method. An empirical formula for calculating peak rates of runoff resulting from rainfall.
Expressed mathematically, the formula is:
Q = CIA
Where:
Q = Peak flow in cubic feet per second (cfs)
C = Runoff coefficient or fraction of runoff to rainfall, dependent on type of surface cover and
topography
I = Rainfall intensity, in inches per hour, for a specific storm and duration
A = Watershed area in acres
Receiving bodies of water. Any water body or stream into which surface waters flow.
Sedimentation. The process by which suspended solids from erosion are transported and deposited.
Site plan. The plan, usually in map form, prepared pursuant to the city council's zoning or other land
development ordinances as a requirement for the development of property.
Stormwater pollution prevention plan (SWPPP). A plan developed by a qualified professional
engineer or person certified in erosion and sediment control to establish controls to limit erosion and
transport of sediment and other pollutants from a project site. The plan shall include the use of best
management practices.
Stormwater runoff. The waters derived from rain falling or snow melting within a tributary drainage
basin, flowing over the surface of the ground or collected in a stormwater drainage system, storm sewer
or watercourse.
Subdivision. As defined in chapter 25 of this Code.
Ten-year Storm. A rainstorm of varying duration and intensity having a 10 percent probability of
being equaled or exceeded in any given year.
Time of concentration. The elapsed time for stormwater to flow from the most distant point in a
drainage basin to the outlet or point in question.
Twenty -five-year storm. A rainstorm of varying duration and intensity having a four (4) percent
probability of being equaled or exceeded in any given year.
Watercourse. Any stream, creek, brook, branch, natural or artificial depression, slough, gulch,
reservoir, lake, pond or natural or manmade drainageway in or into which stormwater runoff and
floodwaters flow either regularly or intermittently.
Watershed.
(a) An area of land that drains down slope to a lowest point. Water shed boundaries follow major
ridgelines around channels and meet at the bottom, where water flows out of the watershed, a
point commonly referred to as a channel, stream, creek, or river.
(b) A region or area bounded peripherally by a topographic divide and draining ultimately to a
particular watercourse or body of water.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-2. - Purpose.
The purpose of this chapter is to lessen or avoid hazards to persons and property caused by
uncontrolled stormwater runoff or by obstructions to drainage and to lessen the degradation of the quality
of surface runoff.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-3. - Applicability.
(1) Any person or government entity within the city shall apply to the city manager or his designee for
approval of a stormwater management plan and obtain a permit before commencing any
development or development activity.
(2) A stormwater management plan shall be required of any platted subdivision for which no
improvement plans have been submitted at the time this chapter takes effect.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-4. - Exemptions.
(1) Development within a subdivision shall not require approval of a stormwater management plan if
each of the following conditions have been met:
(a) Drainage provisions for the project were previously approved and remain valid as part of a final
plat.
(b) The development is conducted in substantial accordance with the stormwater management
provisions contained in the development plan submitted with the final plat as approved.
(2) Development on isolated lots for single-family and two-family dwelling purposes shall not require
approval of a separate stormwater management plan, nor a grading permit, unless the development
involves altering, rerouting, deepening, widening, obstructing or changing in any way existing
drainage facilities, degrades the quality of water, adversely affects any wetland or adversely affects
any sinkhole, watercourse or waterbody; or unless said lot is five (5) acres or more in size. Also, in
order to qualify for exemption the lot must provide the following protection:
(a) Waste and material disposal. All waste and unused building materials (including garbage,
debris, cleaning wastes, wastewater, toxic materials, or hazardous materials) shall be properly
disposed of and not allowed to go offsite or in storm sewers.
(b) Tracking. Each site shall have graveled roads, access drives and parking areas of sufficient
width and length to prevent sediment from being tracked onto public or private roadways. Any
sediment reaching a public or private road shall be removed by street cleaning (not flushing) by
those responsible before the end of each workday.
(c) All excavations, grading, or filling shall have a finished grade not to exceed three to one (3:1).
(d) Sediment shall be controlled and contained on site.
(e) For vacant land held for development, grass and other vegetative ground cover is required.
(f) All erosion control measures must be installed before land disturbing activity can take place and
shall be installed according to the city engineer's standard details.
(g) Disturbed areas which are at a finished grade with installed utilities shall be permanently
seeded and mulched or sodded within seven (7) days.
(h) Single-family lots that remain inactive for fourteen (14) days or more shall be established with
temporary vegetation. This requirement may be waived if the landowner has sold the lot and
construction activity is scheduled to begin within thirty (30) days of being sold.
(i) Slopes that are steeper than five to one (5:1) which are disturbed and are at final grade with
installed utilities shall be covered immediately with seeding, mulch, or other covering
appropriate for the season.
(3) Stormwater management plans may be waived for building construction or other development which
will not adversely impact an existing drainage area or drainage on adjoining properties.
(4) Written notice of intent to commence development shall be delivered to the city manager or his
designee prior to undertaking any development activity, whether exempt from plan provisions or not.
Application for a building permit may constitute notice of intent.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-5. - Stormwater management plan application.
(1) Purpose. The purpose of the stormwater management plan review process is to provide an
organized framework for evaluating and acting upon proposals for development as they can relate to
stormwater management issues.
(2) Required information. It is the responsibility of an applicant to include sufficient information in the
stormwater management plan to enable evaluation of the environmental quality of the affected area,
the potential and predicted impacts of the proposed activity on affected waters, and the effectiveness
and acceptability of the measures proposed by the applicant for preventing or reducing adverse
impacts. Adverse impacts would include any reduction in water quality of stormwater runoff leaving
the project site. The applicant shall furnish the city manager or his designee the stormwater
management plan application form and stormwater management plan, sealed by a professional
engineer or architect registered in the state or by a CPESC. The applicant shall include as part of the
stormwater management plan a stormwater pollution prevention plan (SWPPP) for the project site.
The SWPPP shall describe methods and BMPs proposed to maintain acceptable water quality for
runoff water leaving the site.
(3) It is required that the owner/developer, or their agent, meet with the city manager or his designee to
discuss the proposed development and the stormwater management aspects of the proposed
development during the conceptual layout stage of the project.
(4) The application form required the following minimum information:
(a) The name, address and telephone number of the applicant, and the owner if different from the
applicant.
(b) Name and address of the professional engineer, architect or CPESC.
(c) The legal description of the property.
(5) An application for stormwater permit shall be deemed abandoned one hundred eighty (180) days
after the date of filing, unless an extension has been requested in writing or a permit has been
issued.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4404, art. 1, 12-17-12)
Sec. 23-6. - Stormwater management plan.
A stormwater management plan, including the SWPPP, is to be designed to safely manage the
stormwater runoff for quantity and quality during and after construction. The plan shall be designed to
manage the quality of stormwater runoff during development through erosion and sedimentation controls
and after development through post construction design elements. The SWPPP is to be prepared and
sealed by a professional engineer licensed in the State of Missouri or a CPESC. The plan shall provide or
be accompanied by maps at a minimum scale of one (1) inch is less than or equal to two hundred (200)
feet and other descriptive material, including the basis of computation, showing the following:
(1) Required predevelopment site information (map scales are minimums):
a. Detailed location sketch showing the parcel and major adjacent roads.
b. Topographic map of the site at a scale of one (1) inch is less than or equal to two hundred
(200) feet with maximum five-foot contour intervals, except in floodplains or other areas of
low relief where a smaller interval may be required.
c. Where percolation or exfiltration systems are proposed, information as to the location and
type of vegetative cover and soil types and characteristics representative of the design
condition mapped at a scale of one (1) inch is less than or equal to two hundred (200) feet.
d. Location of streams and other floodwater runoff channels, their normal channels, and the
extent of the floodplains at the established high water elevations, and the limits of the
floodway mapped at a scale of one (1) inch is less than or equal to two hundred (200) feet.
e. Location of lakes, ponds, swamps and detention basins indicating their normal shorelines,
floodplains and lines of inflow and outflow mapped at a scale of one (1) inch is less than or
equal to two hundred (200) feet.
f. Location of farm drains, inlets and outfalls, storm sanitary and combined sewers and
outfalls, septic tank systems and outlets, if any, and seeps, springs and flowing and other
wells mapped at a scale of one (1) inch is less than or equal to two hundred (200) feet.
g. Location and description of nearby existing off-site water management facilities such as
wells, lakes, drainageways, etc., which are potentially directly affected by the proposed
construction or development, mapped at a scale of one (1) inch is less than or equal to two
hundred (200) feet.
(2) For all existing drainage facilities which are to be maintained, altered, or enlarged as part of the
stormwater management system; provide information as to their size, slopes, depths, outfalls,
receiving waters, elevations, cross sections, profiles, construction materials and other design
details as applicable.
(3) Location of all new stormwater facilities, including detention basins and post construction water
quality elements, to be constructed. Design details for each facility shall be provided as
applicable.
(4) Location and extent of existing and proposed impervious surfaces (roads, parking lots,
buildings, etc.) and their elevations. Provide grading and paving plans and specifications.
(5) Location and extent of rights-of-way and easements for the stormwater management system,
including all areas to be dedicated for water management purposes.
(6) Identification and description of any special or required maintenance procedures to keep the
project functioning as designed.
(7) Provide stormwater management system design calculations as follows:
a Design storms used. Design storms to be used are 10 -year, 25 -year, and 100 -year
frequency events, with 30 minute duration. These storms are defined in the NOAA TP 40
Charts.
b. For all detention basins, a plot or tabulation of storage volumes with corresponding water
surface elevations and of the basin outflow rates for those water surface elevations.
c. Acreages and percentage of property proposed as:
1. Impervious surfaces.
2. Pervious surfaces (green areas).
3. Lakes, canals, detention areas, etc.
4. Total acreage of project.
5. Other.
d. Runoff routing calculation showing discharge, elevations, and volumes retained and/or
detained during applicable storm event.
e. Calculations required for determination of minimum building floor and road elevations.
f. Calculations for all inlets, pipes, and ditches shall be submitted for review.
(8) For projects less than one (1) acre, provide a narrative section that describes potential sources
of pollution, project managers for the project and areas over which they have control, temporary
and permanent nonstructural BMPs, temporary and permanent structural BMPs, additional site
BMPs as warranted by the site, BMP implementation schedule, temporary stabilization
practices, dewatering methods, permanent stabilization practices, measures to minimize dust,
construction/waste materials to be stored on site and how they will be disposed, pollutant
sources from other areas than construction, allowable sources of nonstormwater discharge,
how mud/sediment on streets or other property will be handled, how accumulated sediment will
be disposed, and implementation of pollution prevention measures for nonstormwater
discharges.
(9) For projects one (1) acre or greater, provide two (2) bound copies of the SWPPP based on the
EPA SWPPP template. Required information includes identifying contact information for
responsible parties; site evaluation, assessment and planning; documentation of compliance
with other federal requirements; erosion and sediment controls; pollution prevention standards;
and inspection and corrective action.
(10) Describe operation and maintenance procedures for stormwater management facilities, i.e.,
cleaning frequency, access routes, any special equipment or tools to be used. This should
include procedures for transfer of maintenance responsibilities where appropriate.
(11) Identify entity responsible for operation and maintenance of the erosion and sediment control
system after completion of site activities.
(12) The requirements for specific plan elements cited above may be waived by the city manager
or his designee, upon written supportive recommendation of the city engineer. The stormwater
management plan for minor development activities may consist of a certification from a
professional engineer, architect or CPESC that the differential runoff equals zero (0). However,
the developer shall still provide a completed application, the required review fee and SWPPP for
the project site.
(13) The city manager or his designee will ascertain the completeness of the stormwater
management plan application. The city manager or his designee will return incomplete
applications to the applicant for completion and resubmission. After determining that the
application is complete, the city manager or his designee will distribute copies of the application
for review and comment to other persons with special technical expertise as deemed
appropriate. Within a reasonable period after submission of the completed stormwater
management plan application by the applicant, the city manager or his designee shall approve,
approve with specified conditions, or deny the application and shall notify the applicant
accordingly. If the stormwater management plan application is denied or approved with
conditions, the city manager or his designee shall state the reasons for denial or the specified
conditions. If the applicant feels aggrieved due to the denial or conditions, he may appeal the
decision to the city council.
(14) Once the SWPPP is approved, a copy of it shall be kept at the construction site at all times.
The SWPPP shall be updated according to progress of the work that disturbs the soil. Typically
this update will be done weekly. It will be the contractor's responsibility to provide the means of
storing the SWPPP on site.
(15) A stormwater management permit shall be valid for three (3) years after the date of issuance.
If the stormwater management facilities for which the permit was issued are not completed
within three (3) years, the permittee may request a renewal of the said permit. The permit
renewal fee must be paid in full at the time of the renewal request. The permit renewal fees are
outlined on the city fee schedule. The city manager or his designee has the right to approve or
deny any permit renewal request.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4404, arts. 2, 3, 12-17-12)
Sec. 23-7. - Project classification and fees.
(1) For purposes of evaluation, projects will be classified in three (3) categories according to acreage:
Class
(a) Less than twenty-five (25) acres.
(b) Twenty-five (25) acres to two hundred (200) acres.
(c) Over two hundred (200) acres.
(2) The effective acreage for a project is not limited to a fractional part of the total concept, rather if a
project is developed in phases or small plots, the total acreage of the conceptual project will be
considered.
(3) The review fee shall be collected at the time the stormwater management plan application is
submitted by the applicant to the city manager or his designee, and will reflect the cost of the
administration and management of the review process. The fees for the project classes are outlined
on the city fee schedule.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-8. - General design requirements for stormwater management plan and SWPPP.
(1) A stormwater management system shall be provided for protecting lots, roads, streets and buildings
in the project area from the potential adverse impacts of stormwater runoff. Streets, blocks, depths of
lots, parks and other public grounds, and ultimate land usage shall be determined, located and laid
out in such a manner as to reduce the velocity of overland flow and allow the maximum opportunity
for infiltration of stormwaters into the ground, and to preserve and utilize natural streams, channels
and detention basins, and wherever possible, to include streams and floodplains within parks or
other public grounds. The elements of the stormwater management plan should protect area
waterways from pollutants carried by the stormwater runoff.
(2) The maximum allowable release rate of stormwater after development shall be as follows:
(a) The rate shall not exceed the before -development rate for a two year --and ten-year frequency
storm of 30 minute duration.
(b) The twenty -five-year storm shall have the release rate of a ;
+++n,�cen-dear ten-year frequency
storm of 30 minute duration.
(c) The total drainage area must be used in calculating the allowable release rate. The required
storage volume will be based on the project area only, with extraneous flows from upland areas
being pass-through flow or discharged via overflow spillway or other devices.
(d) The runoff from a one -inch rain event shall be GGRtF lied +„ provide water quality improvement.
This is approximately the n RGtie+h P eRt'le raiR on+ managed for water quality improvement
by means of filtration and flow control. Details for this stormwater management element are
located in the City of Cape Girardeau's Standard Specifications and Drawings.
(3) The increased stormwater runoff resulting from the proposed development shall be detained on-site
by appropriate detention basins or by other acceptable techniques. The minimum volume of storage
shall be sufficient to store the volume of the difference between fifteen (15) y ten-year 30 minute
storm under undeveloped conditions and the twenty-five {5) year 30 minute storm under developed
conditions. Control devices shall limit the discharge from storage to a rate no greater than that
prescribed by this chapter. Downstream property, watercourses, channels or conduits shall not
receive stormwater runoff from proposed development at a higher peak flow rate than that which
existed prior to the development. Detention/retention areas should at a minimum filter the stormwater
runoff. When possible, filtration and/or infiltration practices should be incorporated into the site
design.
(a) Where a development site has more than one (1) watershed, the runoff water shall be
controlled within each watershed. Exemption from this requirement must be approved by the
city manager or his designee. With a request for this exemption, the developer will be required
to present information and/or documentation establishing conclusively that no adverse impacts
would occur to adjoining or downstream properties from uncontrolled runoff in a particular
watershed area of the development site.
(4) Generally acceptable locations of the stormwater runoff channels in the design of the project area
may include the following:
(a) In a depressed median of a double roadway, street or parkway, provided the median is wide
enough to permit required roadway shoulders.
(b) Centered on the rear lot lines in a block, or entirely within the rear yards of a single row of lots
or parcels, provided that in either case the lots are deep enough to permit side slopes in the
runoff channel and a building site of the elevation required by other sections of this chapter.
(c) In a depressed area along roadway, street or parkway, provided the area is wide enough to
permit side slopes as required in other sections of this chapter.
(d) Landscaped areas may be designed for use as part of the stormwater management system.
(e) Alternative systems such as curb and gutter and storm sewers that discharge into an
appropriate detention basin may be incorporated into the stormwater management plan.
(f) The smaller, uppermost reaches of drainage channels and swales forming the natural drainage
system near a watershed divide may be relocated or eliminated and incorporated into the
planned system of storm sewers and open channels designed consistent with the requirements
of this chapter.
(5) A continuous easement may be provided abutting rear lot lines as shown in the stormwater
management plan within which utility lines and open drainage facilities may be located and
maintained, but on which no accessory buildings may be constructed. The utility drainage easement
shall be at least twenty (20) feet wide. Within the area so designed for the passage or storage of
waters, no structure may be erected, no fences, shrubbery or trees planted, or changes made to the
prescribed grades and contours of the specified floodwater or stormwater runoff channels.
(6) All storm sewer outfalls shall be so designed, by reason of elevation of the invert, by a flap gate or
by other features, that when the receiving stream is in full flood, the storm sewers will continue to
drain the areas they are designed to serve unless the provision is made for sewer backups into
planned storage locations.
(7) All sanitary sewer manholes constructed in a floodplain, in a street designed for detention, or in an
area designed for the storage or passage of floodwater or stormwater, shall be provided with either a
watertight bolted manhole cover, a watertight concealed pick -hole cover, or be constructed with a rim
elevation at or above the high water elevation of the 100 -year flood or the high water elevation of the
design storm, whichever is applicable to the specific area.
(8) Projects that are to be developed in phases will normally require the submission of a master plan of
the applicant's contiguous land holdings. Applications for individual project phases may be
considered only when the phases are totally independent of, or make sufficient provisions for,
adjacent lands.
(9) All excavations, grading or filling shall have a finished grade not to exceed a 3:1 (three (3) horizontal
to one (1) vertical) slope. Steeper grades may be approved by the city engineer if the excavation is
through rock or the excavation or fill is protected (a designed head wall or toe wall may be required).
(10) Grading plans for sites that exceed one (1) acre shall provide for erosion control and for sediment
controls, or debris basins, silt traps or filters, staked straw bales, a combination of these measures or
other measures approved by the city engineer to remove sediment from runoff waters. Temporary
sediment control measures (structural) shall be maintained until vegetative cover is established at a
sufficient density to provide erosion control on the site.
(11) Where natural vegetation is removed during grading, vegetation shall be reestablished in such a
density as to prevent erosion. Permanent type grasses shall be established as soon as possible
during the next seeding period after grading has been completed. Trees, plants and vegetative cover
should be of native species, when possible. Reference the city development manual and other city
ordinances for examples.
(12) When grading operations are completed or suspended for more than fourteen (14) days between
permanent grass seeding periods, temporary cover shall be provided. All finished grades (areas not
to be disturbed by future improvements) 4:1 slopes or steeper shall be sodded, hydro seeded, or
have erosion control fabric installed; slopes less than 4:1 (four (4) horizontal to one (1) vertical) shall
be mulched at the rate of one hundred (100) pounds per one thousand (1,000) square feet when
seeded.
(13) Ground adjoining project sites (lots) shall be provided with protection from accelerated and
increased surface water, silt from erosion, and any other consequences of erosion. Runoff water
from developed areas (parking lots, paved sites, and buildings) above the area to be developed shall
be directed to diversions, detention basins, concrete gutters, and/or underground outlet systems.
Sufficiently anchored straw bales may be substituted with the approval of the city engineer.
(14) Development along natural watercourses shall have a minimum fifty -foot general maintenance and
drainage easement. The easement shall be measured from the top of the existing stream bank.
Development shall not encroach on said fifty -foot easement. The watercourse shall be maintained by
and be made the responsibility of the appropriate legal entity. Permanent vegetation should be left
intact. Variances will include designed stream bank erosion control measures and shall be approved
by the city engineer. FEMA guidelines shall be followed where applicable regarding site development
in floodplains.
(15) All lots shall be seeded and mulched or sodded, with a density of at least seventy (70) percent
vegetative cover over the entire disturbed area before the certificate of occupancy shall be issued.
(16) BMPs for post construction water quality improvement are to be used when feasible. Designers are
encouraged to implement cooperative use of required landscaping areas and stormwater quality
measures. Examples of these BMPs are located in the city standards and specifications.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4404, arts. 46, 12-17-12; Ord. No. 4805, arts. 13, 1-
19-16)
Sec. 23-9. - Hydraulic design considerations.
(1) Stormwater systems will be designed with sufficient hydraulic capacity as a minimum for the
following frequencies and durations:
(2) The city manager or his designee may require alternative designs or features to reduce the cost of
long-term maintenance.
(3) In critical areas, the city manager or his designee may require additional hydraulic capacity above
the minimums set forth above, up to the 100 -year frequency design.
Type of
Design
Facility
Frequency
(a)
Detention basins
25 -year
(b)
Primary drainage systems
25 -year
(c)
Bridges
50 -year
Secondary drainage systems, i.e., crossdrains and ditches for internal subdivision
15 yea
(d)
10 -year
drainage
30 min
(2) The city manager or his designee may require alternative designs or features to reduce the cost of
long-term maintenance.
(3) In critical areas, the city manager or his designee may require additional hydraulic capacity above
the minimums set forth above, up to the 100 -year frequency design.
(4) The city manager or his designee may require a developer to improve the stormwater facilities
immediately upstream or downstream of a development if adverse impacts from said development
are foreseen. The developer will be responsible for all costs associated with the improvements.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-10. - Stormwater management system design requirements.
(1) Calculations. The design of the stormwater system shall be in accordance with the City of Cape
Girardeau's Storm Drainage Design Manual (if available). If not available, the development
calculations shall be based on the minimum of one (1) fifteen -minute rainfall using the following:
Watershed
Area
(acres)
0-25
Method
Rational (See Note 1)
>25
Technical Release 55 (TR -55) (See Note 2)
Note 1: Rational Method shall be as identified in Missouri Department of Transportation Design
Manual Chapter IX - Hydraulics and Drainage current edition.
Note 2: Technical Release 55 (TR -55) shall be as identified in the NRCS Urban Hydrology for
Small Water Sheds.
(2) Open channels.
(a) Open channels, natural or improved, may be placed at the rear or side of properties upon
approval of the city engineer where the design provides adequate protection to the existing and
future property and structures. Such protection shall be through the provision of a fifty-year
floodplain setback and a minimum distance from the toe of bank to the setback of fifty (50) feet.
This drainage setback line shall be shown on the final plat. Permanent vegetation, existing
ground elevation, and grades within the fifty -foot setback area shall be left intact and
undisturbed on channels with watersheds of one hundred (100) acres or more unless
modification is approved in writing by the director or his designee.
(b) Area inlets shall be required behind the curbs to intercept overland flows greater than one (1)
cfs to prevent flows from crossing sidewalks and/or curbs.
(3) Inlets and junction boxes. Inlets, junctions boxes and inlet spacing shall be per the city's standard
details and as approved by the city engineer. When locating inlets in sump locations consideration
must be made with respect to the major drainage system. A 100 -year 30 minute storm design event
shall not cause buildings to flood in the event that a single inlet becomes blocked. In new
developments the 100 -year 30 minute design storm elevation shall be mapped on the final plat as a
building setback. Overland relief to another inlet or surface channel shall be provided to protect
property.
(4) Enclosed systems.
(a) The outlet of an enclosed system shall have sufficient energy dissipation provided to negate
the increases posed by development as approved by the city engineer.
(b) Building gutter drainage systems may not be discharged directly into the city's enclosed
system.
(c) If development plans call for the enclosure of an existing, natural drainageway which carries
greater than fifty (50) cfs during the design storm event, the enclosure shall be sized for a fifty-
year tWeRty Min, to 30 minute storm event. Upstream inundation shall be checked. Where
inundation extends beyond the site property line and exceeds the design water surface
elevation of the natural drainway/channel, a backwater ponding easement from the affected off-
site property owner(s) shall be required prior to final plan approval. A reduction in the design
storm requirement may be granted by the city engineer when existing off-site, downstream
storm sewer would be smaller than the required on-site, upstream sewer and the downstream
storm sewer are not designed to intercept/pass the fifty-year twenty -minute storm event.
(5) Detention design criteria. Detention in the overall system, including swales, lakes, canals,
greenways, etc., shall be provided as follows.
(6) General.
(a) Storage volumes. The minimum volume of storage provided in detention basins, together with
such storage as may be authorized in other on-site facilities, shall be sufficient to store the
volume of the difference between the f;fteeR (15) „oar ten-year 30 minute storm under
undeveloped conditions and the twenty-five {25) year 30 minute storm under developed
conditions.
(b) Outlet control structures. Outlet control structures shall be designed to operate simply and
automatically. They will limit discharges into existing or planned downstream channels or
conduits so as not to exceed predetermined maximum authorized peak flow rates.
(c) Release rate. A release rate shall be calculated for a two , te^-, or twenty five_„ten-year 30
minute storm for the proposed development in the condition prior to the proposed development.
(d) Emergency spillway. Emergency overflow facilities must be provided in all instances so that
stored waters will not exceed the safe capacity of the basin. At a minimum, the emergency
spillway must be able to pass without damage the 100 -year 30 minute storm.
(e) Appearance. Designs should result in aesthetically pleasing configurations which will enhance
public acceptability.
(7) Dry -detention facilities.
(a) Perimeter maintenance easements of twenty (20) feet (minimum) width at slopes no steeper
than three to one (3:1) (horizontal to vertical) shall be provided.
(b) Side slopes of the facility shall not be steeper than three to one (3:1) (horizontal to vertical).
(c) Provisions must be incorporated to facilitate complete interior drainage to dry bottom basins, to
include the provision of natural grades to outlet structures, longitudinal and transverse grades to
perimeter drainage facilities, or the installation of subsurface drains.
(d) Multipurpose features may be designed to serve secondary purposes for recreation, open
space or other types of use which will not be adversely affected by occasional or intermittent
flooding.
(e) In no case shall the limits of maximum ponding elevation of a dry -detention facility within two
(2) feet vertically below the lowest sill elevation be closer than twenty-five (25) feet horizontally
from any building. The entire reservoir area shall be seeded, fertilized and mulched, sodded or
paved.
(f) Fully paved low flow channels are prohibited. The flow channel for low flow events shall be
reinforced turf or open sectioned pavers with grass or aggregate to allow filtering of the
stormwater and to support mowing equipment. Other methods may be used as approved.
(8) Wet -detention facilities.
(a) Perimeter maintenance and operation easements of twenty (20) feet (minimum preferable)
width at slopes no steeper than three to one (3:1) (horizontal to vertical) shall be provided.
(b) Control elevations should be no higher than two and one-half (2'/2) feet below the minimum
road centerline elevation in the area served by the control device in order to protect the road
subgrade when structures are constructed near roads.
(c) Side slopes shall not be steeper than three to one (3:1) (horizontal to vertical) out to a depth of
two (2) feet below the control elevation, then as steep as soils stability will allow.
(d) If fish are to be used to help keep the basin clean, at least one-quarter ('/4) of an area of the
permanent pool must be a minimum depth of ten (10) feet.
(e) For emergency purposes, cleaning or shoreline maintenance, facilities shall be provided or
plans prepared for the use of auxiliary equipment to permit emptying and drainage.
(f) In no case shall the limits of maximum ponding elevation of a wet -detention facility within two
(2) feet vertically below the lowest sill elevation be closer than thirty (30) feet horizontally from
the lowest sill elevation of any building.
(9) Underground storage. All or a portion of the detention storage may also be provided for in
underground facilities, as long as all applicable requirements of this chapter are met. Details of such
designs are to include type of facility, depth and volume of storage, details of inlet and outlet devices
and locations, emergency overflow provisions, and measures to be used for surface water and
groundwater pollution control.
(10) Design alternatives. The above listing of design criteria is not intended to preclude the use of other
known state -of -the art methods and available best management practices and should not be
construed as a mechanism to discourage innovative design concepts.
(11) Developments adjoining a floodplain. Where a development adjoins or encompasses a portion of a
floodplain for a 100 -year flood, the following shall apply:
(a) The applicant shall show the floodplain and floodway on the stormwater management plan.
(b) The applicant shall include in the stormwater management plan all other plans, plats,
specifications, etc., required by federal, state, county and/or municipal laws or regulations
detailing such provisions or restrictions as are necessary to comply with the following:
All applicable zoning and subdivision requirements.
2. All applicable building code requirements.
3. All requirements of other federal, state or local agencies exercising jurisdiction over the
area.
(12) Channel flow The applicant shall not alter any channel in such a way that would prohibit any
section of the channel from conveying, in its post -development state, the same amount of flow at the
same or lower maximum water elevation that it conveyed in its predevelopment state.
(13) Modifications of channel. The applicant shall furnish, for the city manager's or his designee's
review and approval, the following information pertaining to proposed channel modifications:
(a) Typical cross sections of the existing and proposed channel.
(b) Plan view of the channel showing the location of existing constructions, obstructions and other
nontypical areas.
(c) Hydrographs and/or flood routing calculations and backwater curve profiles of the proposed
waterway corresponding to a storm r iRteFVal Of e h Rdred (100) years 100 -year 30
minute storm.
(d) Engineering evaluation of all potential increases in flood hazards to the adjacent upstream or
downstream private or public lands and facilities located thereon, showing provisions for
eliminating any and all adverse impacts on such land and facilities at no public cost.
(e) Minimum finished floor elevations which shall be set at or above the maximum water surface
elevation as determined by either or both of the following:
1. "Flood Insurance Rate Map" published by the Federal Emergency Management Agency.
2. Backwater curve profiles of the proposed waterway due to a 100 -year 30 minute storm
recurrence interval.
(f) Designation on the final plan of all areas reserved for flood routing, detention or storage,
together with the required wording pertaining to restrictions, dedications and maintenance
responsibilities of such areas.
(14) Detention storage. If detention storage is provided within a floodplain, only the net increase in
storage volume above that which naturally existed on the floodplain shall be credited to the
development. No credit will be granted for volumes below the elevation of the regulatory flood at that
location unless compensatory storage is also provided.
(15) Verification of adequacy. Analysis of all elements of design is to be verified by the engineer of
record submitting the plan. The following outline is provided to ascertain that certain critical elements
are in workable compliance with the aims of this chapter. For projects less than fifty (50) acres in
area there is no need for submittal of routing calculations or tabulated proof of adequacy of tributary
runoff for detention; however, it is recommended that verification be made of:
(a) Volume of detention for the total project.
(b) Tributary (Q) peak runoff to basin.
(c) Balanced maximum outflow rate from the low -flow structure.
(d) Ratios of inflow to outflow rates.
(e) Sizing of the overflow facilities.
(f) Stability of detention dikes.
(g) Safety features.
(h) Maintenance features.
For projects of fifty (50) acres or greater but less than two hundred (200), routing calculations shall
be submitted in legible tabulated form. Proof of adequacy of volume of detention and sizing computations
for low -flow structure shall also be submitted. Features of stability and safety may also need to be
documented if the scope of the project requires special attention in this area of design.
Projects over two hundred (200) acres in area shall provide documented verification of adequacy
according to scope and complexity of design.
(16) Installation of stormwater runoff control measures. Positive stormwater runoff control shall be
provided for during development. Stormwater management plans shall include a schedule for the
installation, construction or modification of all drainage facilities. Erosion control measures and a
schedule for their installation shall be shown on the stormwater management plan. Installation of
drainage facilities and erosion control measures shall proceed as scheduled in the approved
stormwater management plan.
(17) Erosion and sedimentation control criteria. The best management practices to control the
occurrence of erosion and sedimentation are to be incorporated into the plan for the time land is
disturbed by development activity. Permanent controls and practices shall also be identified where
they are necessary to control an ongoing potential for erosion and sedimentation. Types of best
management practices include, but are not limited to:
(a) Use of state approved standard specifications of the city.
(b) Tree, topsoil and vegetative cover preservation and restoration.
(c) Surface stabilization with various natural or manmade materials.
(d) Runoff control measures that address quantity and quality of runoff waters such as berms,
dikes, sediment traps, filtration and infiltration methods and barriers.
(e) Inlet and outlet protection.
(f) Stream bank protection.
(g) Scheduling of development activities and protection measures for minimal impact.
(h) For post construction water quality controls, landscaped areas may be used.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4805, arts. 46, 1-19-16)
Sec. 23-11. - Rights-of-way and easements.
(1) All stormwater management facilities shall be constructed within an easement or right-of-way
dedicated for stormwater management use and connected to a public road or other location from
which operation and maintenance is legally available. Minimum rights-of-way and maintenance
easements shall be provided by instrument or plat dedication for all waterways used to convey or
detain runoff. Where permanent maintenance will be provided by the property owner, maintenance
easements or rights-of-way may not be required. The minimum widths of rights-of-way and
easements shall be as follows:
Facility
Maintenance
Access Width
Open drainage channel or facility
50 feet from top of bank
Greenways
Width of greenway
Pipes and culverts
20 feet centered
Detention areas
20 feet continuous around total area
Connecting access
20 feet
(2) Easements must include the "top of the bank width" and the maintenance access width.
(3) The maintenance access width begins at the point of the bank or slope of the facility.
(4) Additional maintenance access width may be required by the city manager or his designee in
special circumstances where more width on one (1) or both sides is necessary for maintenance
purposes.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-12. - Maintenance responsibilities for stormwater management facilities.
(1) Purpose. The purpose of this section is to establish maintenance standards to ensure that after
stormwater management facilities have been properly designed and constructed, they continue to
function properly. Continued proper functioning is highly dependent upon the proper maintenance of
the facilities. Proper long term function is critical to maintaining the water quality improvement
aspects of the stormwater management facilities.
(2) Design of facilities. Maintenance costs over a period of years will generally surpass the costs of
initially constructing water management facilities. The applicant and the city manager or his designee
should utilize all appropriate methods, approaches and techniques to design and construct these
facilities in such a manner that fulfills the requirements of this chapter, facilitates their inspection,
facilitates cleaning and repair activities, and minimizes future maintenance costs. The design should
include provisions for access to areas requiring cleaning and/or maintenance work after the project is
constructed.
(3) Inspection of facilities. Inspection of stormwater management facilities should be performed
annually, at a minimum. The owner is responsible to have the inspection performed by a competent
individual or firm. A written report of the inspection, including findings and recommendations, is to be
sent to the city manager or his designee. When cleaning or repairs are recommended, the owner
shall send a subsequent report to the city manager or his designee documenting that the
recommended action has been completed. The city manager or his designee has the authority to
inspect all stormwater facilities on public or private property to confirm proper maintenance is being
performed. Enforcement shall follow the guidelines set forth in this chapter.
(4) Maintenance responsibilities. The growth of noxious weeds, the creation of conditions which support
the growth of mosquitoes and other insects, and the decrease in available storage by accumulated
sediments shall be controlled. The cleanup of accumulated debris, flotsam and other materials after
runoff events have subsided shall be assured.
(a) Detention facilities, when mandatory, are to be built in conjunction with the storm sewer
installation and/or grading. Since these facilities are intended to control increased runoff, they
must be partially or fully operational soon after the clearing of the vegetation. Silt and debris
connected with early construction shall be removed periodically from the detention area and
control structure in order to maintain close to full storage capacity.
(b) The responsibility for maintenance of stormwater management facilities in single -lot
development projects shall remain with the owner, developer and general contractor until final
inspection of the development is performed and approved, and a legal occupancy permit, where
applicable, is issued. After legal occupancy of the project, the maintenance of stormwater
management facilities shall be vested with the owner of the project.
(c) The responsibility for maintenance of stormwater management facilities in subdivision projects
shall remain with the developer until such time as responsibility is transferred, under appropriate
legal arrangements, to the private individual owners in the subdivision, the trustees of the
subdivision, the city or such other maintenance entity or authority as may be proposed and
approved by the city council.
(d) If responsibility is to be transferred to the private individual owners in the subdivision, the
developer shall assure perpetual maintenance of the drainage management facilities, including
detention systems, if any are included, through the adoption of maintenance agreements or
covenants for any facilities that remain in private ownership. Such agreements or covenants
shall be subject to the approval of the city manager or his designee.
(e) If the responsibility is to be transferred to the trustees of the subdivision, the developer shall
establish a suitable indenture of trust. Upon release of escrows required for the subdivision
development, the responsibility for maintenance shall be vested in the trustees of the
subdivision by virtue of the trust indenture. The indenture of trust shall clearly indicate resident
responsibility for maintenance and shall be subject to the approval of the city manager or his
designee.
(5) Performance and maintenance security. Security against defects in workmanship shall be required
for any portion of the drainage management facilities dedicated to the public. The terms of the
performance security shall apply to any repairs needed and maintenance needed during the two-
year period following completion. Inspection and repair of defects shall be required as a condition of
release of the posted security.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-13. - Illicit discharges.
(1) Prohibition of illicit discharges.
(a) Pursuant to the National Pollutant Discharge Elimination System (NPDES) municipal separate
storm sewer system (MS4) program illicit discharges to the MS4 are being defined as illegal.
This is accomplished by identifying allowable nonstormwater discharges into the MS4 in the
best interest of the City of Cape Girardeau, Missouri.
(b) Nonstormwater discharge means any discharge to the MS4, that is not rainwater or snow/ice
melt. Except as hereinafter provided, all nonstormwater discharges into the MS4 are prohibited
and declared to be unlawful. Common pollutants in the area served by the City of Cape
Girardeau MS4 are, but not limited to, the following. Discharge of these items into the city
stormwater system is prohibited:
Petroleum products, including, but not limited to, oil, gasoline, diesel fuel and grease.
Fats, oils and grease.
Paints.
Process water from industrial or domestic operations.
Chemicals, including household type products.
Solid waste.
Pet waste.
Phosphates and soaps.
Pesticides, fertilizers and herbicides.
Solvents and degreasers.
Sanitary sewage.
Antifreeze and other automotive products.
Chemically treated cooling water.
Yard waste including trees and parts of trees.
Any discharge causing interference in the MS4.
(2) Allowable nonstormwater discharges. Unless the City of Cape Girardeau, MoDNR, EPA or other
regulatory agency has identified them as a source of pollutants to the waters of the State of Missouri,
the following nonstormwater discharges into the municipal separate storm sewer system are lawful:
Water line flushing or other potable water sources.
Landscape irrigation or lawn watering with potable water.
Diverted stream flows.
Rising groundwater.
Groundwater infiltration to storm drains.
Pumped groundwater.
Foundation or footing drains.
Crawl space pumps.
Air conditioning condensation.
Springs.
Noncommercial washing of vehicles.
Natural riparian habitat or wetland flows.
Swimming pools (if dechlorinated).
Firefighting activities.
Discharges specified in writing by the City of Cape Girardeau as being necessary to protect
public health and safety.
Waters used to wash vehicles and equipment, provided that there is no discharge of soaps,
solvents, or detergents used for such purposes.
Water used to control dust.
Routine external building wash down that does not use detergents.
Construction dewatering water that has been treated by an appropriate control.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4404, art. 7, 12-17-12)
Sec. 23-14. - Plan adherence.
The applicant shall be required to adhere strictly to the stormwater management plan as approved.
Any changes or amendments to the plan must be approved by the city manager or his designee in
accordance with the procedures set forth in this chapter obtaining stormwater management plan
approval. Enforcement officials shall be, and are herein, granted inspection rights and right -of -entry
privileges in order to ensure compliance with the requirements of this chapter.
(1) Pre -disturbance inspection. A pre -disturbance inspection shall be requested by the permittee at
least forty-eight (48) hours prior to commencement of site disturbance activities on projects one
(1) acres or greater, to inspect erosion and sediment control and other site BMPs.
(Ord. No. 4253, § 1, 8-15-11; Ord. No. 4805, art. 7, 1-19-16)
Sec. 23-15. - Enforcement.
(1) Approved projects. The city manager or his designee shall carry out periodic inspections of the
project site to ensure the applicant's compliance with this chapter. If it is determined that the project
is not being carried out in accordance with the approved stormwater management plan, the city
manager or his designee is authorized to enforce compliance through the following steps in this
order:
(a) Written notice. Issue written notice to the applicant or owner, specifying the nature and location
of the alleged noncompliance, with a description of the remedial actions necessary to bring the
project into compliance within a reasonable specified time.
(b) Stop work order. If the remedial work identified in the written notice is not completed within the
specified time issue a stop work order directing the applicant or owner to cease and desist all or
any portion of the work which violates the provisions of this chapter.
(c) Revocation of approval. Should the applicant or owner not bring the project into compliance
following receipt of the written notice and stop work order, he shall then be subject to immediate
revocation of his stormwater management plan approval and to the penalties described in this
chapter.
(d) Appeal. Any notice, order or revocation issued pursuant to subsection (a)(1), (a)(2) or (a)(3)
above shall become final unless the person named therein requests, in writing, no later than ten
(10) days after the date such notice, order or revocation is served, a hearing before the city
council.
(2) Unapproved projects. With respect to any development or development activity determined by the
city manager or his designee to be subject to this chapter, and being carried out without approval,
the city manager or his designee is authorized to enforce compliance through he following steps in
this order:
(a) Written notice. Issue written notice to the owner specifying the nature and location of the
alleged noncompliance, with a description of the remedial actions necessary to bring the project
into compliance within a reasonable specified time.
(b) Stop work order. If the remedial work identified in the written notice is not completed within the
specified time, issue a stop work order directing the owner to cease and desist all or any portion
of the work which violates the provisions of this chapter.
(c) Noncompliance with stop work order. Should the owner not bring the project into compliance
with the written notice and stop work order he shall then be subject to the penalties described in
this chapter.
(d) Appeal. Any notice, order or revocation issued pursuant to subsection (b)(1), (b)(2) or (b)(3)
above shall become final unless the person named therein requests, in writing, no later than ten
(10) days after the date such notice, order or revocation is served, a hearing before the city
council.
(3) Post -construction maintenance of stormwater facilities. The city manager or his designee shall carry
out periodic inspections of public and private stormwater management facilities to ensure compliance
with the maintenance requirements of this chapter. If it is determined that proper maintenance is not
being carried out in accordance with the approved stormwater management plan, the city manager
or his designee is authorized to enforce compliance through the following steps in this order.
(a) Written notice. Issue written notice to the owner, specifying the nature and location of the
alleged noncompliance, with a description of the remedial actions necessary to bring the
stormwater management facility into compliance within a reasonable specified time.
(b) Stop work order. If the corrective action identified in the written notice is not completed within
the specified time, issue a stop work order directing the applicant or owner to cease and desist
all or any portion of the work which violates the provisions of this chapter, if applicable.
(c) If the corrective action identified in the written notice is not completed within the specified time,
issue a summons through nuisance abatement. The summons shall set a time frame to
complete the corrective action(s). Failure to comply with the summons shall lead to a court
hearing before the city court.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-16. - Penalties for violation.
(1) General. Violation of the provisions of this chapter or failure to comply with any of its requirements,
including conditions and safeguards established in connection with variances or special use permits,
shall constitute a misdemeanor. Any person who violates this chapter or fails to comply with any of
its requirements shall upon conviction thereof be fined not more than five hundred dollars ($500.00)
or imprisoned for not more than three (3) months, or both, and in addition, shall pay all costs and
expenses involved in the case. Each day such violation continues shall be considered a separate
offense.
(2) Corrective actions. Nothing herein contained shall prevent the City from taking such other lawful
action as is necessary to prevent or remedy any violation. All such costs connected therewith shall
accrue to the person responsible.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-17. - Vested rights.
This chapter shall not in any way limit or modify the vested rights of any person to complete any
development or improvement to lands based upon prior law, where a previous permit or authorization has
been granted or applied for and where such previous permit or authorization remains in effect. The city
may acknowledge vested rights in other circumstances where it is equitable and just.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-18. - Conflict with other ordinances and codes.
In case of conflicts within this chapter or any part thereof, and the whole or part of any other existing
or future ordinance or code of the city, the most restrictive in each case shall apply.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-19. - Other permits.
(1) Before starting any work regulated by this chapter, an applicant shall comply with the requirements
set forth in all other applicable ordinances with respect to the submission and approval of preliminary
and final subdivision plats, site plans for construction and rezoning improvement plans, and building,
grading and zoning permits, along with those set forth in this chapter and as may be required by
state statutes and the regulations of any department of the state.
(2) A discharge permit from the State of Missouri shall be obtained individually or under the applicable
general permit for any activity regulated under the Department of Natural Resources Clean Water
Commission (10 CSR 20) Storm Water.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-20. - Interpretation.
In the interpretation and application of this chapter, the provisions expressed herein shall be held to
be the minimum requirements and shall be liberally construed in favor of the city and shall not be deemed
a limitation or repeal of any other powers granted by state statutes.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-21. - Abrogation and greater restrictions.
It is not intended by this chapter to repeal, abrogate or impair any existing easements, covenants or
deed restrictions. However, where this chapter imposes greater restrictions, the provision of this chapter
shall prevail.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-22. - Liability disclaimer.
The performance standards and design criteria set forth herein establish minimum requirements
which must be implemented with good engineering practice and workmanship. Use of the requirements
contained herein shall not constitute a representation, guarantee, or warranty of any kind by the
municipality or its officers and employees of the adequacy or safety of any drainage management
structure or use of land. Nor shall the approval of a stormwater management plan and the issuance of a
permit imply that land uses permitted will be free from damages caused by stormwater runoff. The degree
of protection required by these regulations is considered reasonable for regulatory purposes and is based
on historical records, engineering and scientific methods of study. Larger storms may occur or stormwater
runoff heights may be increased by manmade or natural causes. Enforcement of these provisions,
therefore, shall not create liability on the part of the municipality or any officer of the municipality with
respect to any legislative or administrative decision lawfully made hereunder, nor shall compliance relieve
an owner, developer, and/or permittee from responsibility under any circumstances where liability would
otherwise exist.
(Ord. No. 4253, § 1, 8-15-11)
Sec. 23-23. - Final approval required.
(1) Any stormwater management facility for which a permit has been issued as a part of a subdivision
improvement plan must be included with as -built drawings and certified to have been constructed in
conformance with the approved drawings.
(2) Any stormwater management facility for which a permit has been issued individually or as a part of a
site development plan must be included with as -built drawings certified to have been constructed in
conformance with the approved drawings prior to issuance of a certificate of occupancy.
(3) The certification in a. and b. above must be by a professional engineer licensed in Missouri or a
CPESC.
(Ord. No. 4805, art. 8, 1-19-16)
Editor's note— Ord. No. 4805, art. 8, adopted Jan. 19, 2016, repealed the former § 23-23, and
enacted a new section as set out herein. The former § 23-23 pertained to similar subject matter
and derived from Ord. No. 4253, § 1, adopted Aug. 15, 2011.