Cross References — As to administration, Title I; as to building, ch. 500; as to building code, §§500.010 et seq.; as to electrical code §§500.040 et seq.; as to flood damage prevention, ch. 415; as to mosquito control, ch. 240; as to housing, ch. 515; as to land development standards for manufactured homes, §§405.120 et seq.; as to planning and zoning, ch. 400; as to plumbing code, §500.060; as to streets and sidewalks, ch. 510; as to utilities, Title VII; as to subdivisions, ch. 410; as to zoning regulations, ch. 405.
[R.O. 2007 §31½-1; Ord. No. 6659 §2(Exh. A), 10-20-2003]
The purpose of this Chapter is to lessen or avoid hazards to
persons and property caused by uncontrolled storm water runoff or
by obstructions to drainage and to lessen the degradation of the quality
of surface runoff.
[R.O. 2007 §31½-2; Ord. No. 6659 §2(Exh. A), 10-20-2003; Ord. No. 23-01, 1-17-2023]
Unless specifically defined, words or phrases shall be interpreted
so as to give them the meanings they have in common usage and to give
this Chapter its most reasonable application. The term "shall" is
always mandatory and not discretionary; the word "may" is permissive.
The duly appointed City Manager of the City or his/her designated
representative.
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.
The record owner or his/her authorized representative of
a tract of land that is the site of development or development activity
within the scope of this Chapter.
The elevation at any location delineating high waters having
a one percent (1%) probability of being equaled or exceeded in any
given year (also known as the one-hundred-year flood).
Structural and non-structural Best Management Practices to
minimize water quality impacts.
Any structure built for the support, shelter or enclosure
of persons, animals, chattels or movable property of any kind.
The maximum ability of a storm drainage facility to convey,
detain or retain storm water flows without causing substantial damage
to public or private property and in the case of a pipe, without surcharging.
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.
The City of Poplar Bluff, Missouri.
Any channel, pipe, sewer or culvert used for the conveyance
or movement of water, whether open or closed.
An element of a discharge structure that allows the gradual
release of water under controlled conditions.
Design elevation of a discharge structure at which, or below
which, water is contained behind the structure.
The City Council of Poplar Bluff, Missouri.
The delay of storm runoff prior to discharge into receiving
waters.
A facility constructed or modified to restrict the discharge
of storm water to a prescribed maximum range 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
denatured after having provided its planned detention of runoff during
a storm event.
The temporary detaining or storage of storm water in storage
basins, on 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.
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.
Any individual, firm, corporation, association, partnership
or other entity involved in commencing proceedings under this Chapter
to effect the development of land for himself/herself or another.
Any manmade change to improved or unimproved land including,
but not limited to, buildings or other structures, mining, dredging,
filling, grading, paving, excavating or drilling operations. Any subdivision
of land as defined in the City's subdivision regulations, excluding
minor subdivisions.
The difference in rate and volume of storm water runoff from
a parcel or project in its undeveloped natural condition and its developed
condition is known as differential runoff.
The rate of outflow of water from detention storage.
Structural device, usually of concrete, metal, timber, etc.,
through which water is discharged from a project to the receiving
water.
The area from which water is carried off by a drainage system;
a watershed or catchment area.
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.
The surface or subsurface system that conveys water from
or over the land, including all watercourses, water bodies and wetlands
(also referred to as the storm water management system or storm sewer).
A grant by a property owner to the public, a corporation
or a person of the use of land for a specific purpose.
Height in feet above mean sea level according to National
Geodetic Vertical Datum (NGVD).
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 convoying the maximum design flood
discharge through the impoundment, without overtopping the dam.
The volume and rate of flow of storm water discharged from
a drainage area, which is or will be in excess of that volume and
specified in this Chapter.
The higher portion of the flood plain, immediately adjacent
to and on either side of the floodway, occupied by quiescent or slow-moving
waters during floods.
The special flood hazard land adjoining a watercourse, the
surface elevation of which is equal to or lower than the base flood
elevation (the one-hundred-year flood), which is subject to periodic
inundation during floods.
The channel of a watercourse and those portions of the adjoining
flood plain that are reasonably required to carry and discharge the
base flood.
The elevation of floodwaters of a flood of specified frequency
or occurrence at any given point.
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, roof, sidewalks,
parking lots and similar structures.
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.
Construction on any development or part of a common development
that disturbs one (1) acre or more.
A feature or structure for temporarily storing excess storm
water 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.
A feature or structure for temporarily storing excess storm
water, having devices for controlling the rate of release of the stored
waters and located within the sites where the runoff originates.
Rainstorm of varying duration and intensity having a one
percent (1%) probability of recurring in any one (1) year.
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.
The maximum rate of flow of water at a given point in a channel
or conduit resulting from a predetermined storm or flood.
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.
Those conditions that existed naturally prior to any manmade
improvements or developments. This is assumed to be five percent (5%)
impermeable over the entire site.
Includes that portion of the watercourse whose total tributary
area exceeds or equals fifty (50) acres and any drainage facilities
therein.
An engineer duly registered or otherwise authorized by the
State to practice in their field of engineering.
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
|
Any water body or stream into which surface waters flow.
The plan, usually in map form, prepared pursuant to the Governing
Body's zoning or other land development ordinances as a requirement
for the development of property.
See "DRAINAGE SYSTEM."
The approved program of action for controlling storm water
runoff and preventing harmful pollutants from being washed by storm
water runoff from development on a property or subdivision.
All natural and manmade drainage facilities which are defined
as part of the storm water management plan.
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 storm water drainage system, storm sewer or watercourse.
As defined in Chapter 410, Subdivisions Regulations, of the Code of Ordinances of the City of Poplar Bluff, Missouri.
The elapsed time for storm water to flow from the most distant
point in a drainage basin to the outlet or point in question.
Rainstorms of varying duration and intensities having a four
percent (4%) probability of being equaled or exceeded in any given
year.
Any stream, creek, brook, branch, natural or artificial depression,
slough, gulch, reservoir, lake, pond or natural or manmade drainage
facility in or into which storm water runoff and floodwaters flow,
either regularly or intermittently.
[R.O. 2007 §31½-3; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
Any
person, firm, corporation, business or government entity within the
municipality shall apply to the administrative officer for approval
of a storm water management plan, as defined herein, and obtain a
storm water permit, waiver or exemption before commencing any development
or development activity as defined herein.
B.
Any
property to be annexed into the City shall be subject to these regulations.
A storm water management permit, waiver or exemption shall be granted
prior to final approval of annexation.
C.
Any
redevelopment that will in any way alter the existing storm water
management plan, including, but not limited to, any development that
may increase the runoff from the site, alter the existing detention
facilities, alter existing drainage facilities or any clearing operations
that will require temporary erosion, control, shall require a storm
water permit, waiver or exemption before any such activity begins.
D.
Detention
requirements are directly related to permitted land use in the zoning
ordinance of the City of Poplar Bluff. The permitted densities and
minimum lot areas are important factors in the anticipated runoff.
Table I lists the zoning districts with the major permitted use category,
minimum lot area and the corresponding percent of imperviousness.
E.
For
permitted land uses other than those listed in Table I, such as schools,
churches, fire stations, etc., the rate of imperviousness shall be
determined by the same method as for commercial uses listed in Table
I. For conditional land use in any zoning district, the same ratio
determination criteria shall apply.
|
TABLE I. STORM WATER DATA BY ZONING DISTRICTS
| |||
|---|---|---|---|
|
Zone
|
Major Permitted Areas
|
Minimum Lot Area
|
Percent of Impervious Area for Design Standards In Table
II
|
|
"RS-1"
|
Residential
|
15,000
|
35
|
|
"RS-2"
|
Residential
|
10,000
|
35
|
|
"RS-3"
|
Residential
|
8,000
|
35
|
|
"RS-4"
|
Residential
|
6,000
|
45
|
|
"RD-1"
|
Duplex (residential)
|
7,000
|
45
|
|
"RA-1"
|
Apartment
|
Determined percentage of impervious area by ratio of imperious
surface area to total area
| |
|
"RA-2"
|
Apartment
| ||
|
"C-1"
|
Commercial
| ||
|
"C-2"
|
Commercial
| ||
|
"C-3"
|
Commercial
| ||
|
"C-4"
|
Commercial
| ||
|
"M-1"
|
Industrial
| ||
|
"M-2"
|
Industrial
| ||
|
"O-1"
|
Commercial
| ||
[R.O. 2007 §31½-4; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
All
developments or redevelopments of property within the City shall be
subject to the provisions of the storm water management regulations.
B.
Written
notice of intent to commence development shall be delivered to the
administrative officer prior to undertaking any development activity,
whether exempt from plan provisions or not. If exempt from plan provisions,
a storm water management permit application shall be submitted for
exemption.
C.
Applicants for exemption shall submit a storm water permit application for review and approval by the administrative officer. The application shall include all minimum information as required in Section 425.060. In addition, the application shall be accompanied by a brief description of the proposed improvements and construction activities. Applicants for exemptions will not be required to provide a storm water management plan or waiver certification by a professional engineer.
D.
Development
within a subdivision shall not require approval of a storm water management
plan if each of the following conditions have been met:
1.
Drainage provisions for the project were previously approved and
remain valid as part of a final plat;
2.
The development is conducted in substantial accordance with the storm
water management provisions contained in the development plan submitted
with the final plat as approved.
3.
The property zone designation has not changed, unless it is determined
by the administrative officer that the zone change will not create
additional runoff beyond that allowed by the subdivision's storm water
management plan.
E.
Development
or redevelopment on isolated lots of record for single-family and
two-family dwelling purposes may be exempt of a storm water management
plan if the development does not involve: altering, rerouting, deepening,
widening, obstructing or changing in any way existing drainage facilities;
degrading the quality of water, adversely affecting any wetland or
adversely affecting any sinkhole, watercourse or water body; or causing
any negative impact on storm water runoff or down-stream storm water
facilities or properties.
F.
The
administrative officer may approve or deny any exemption based on
the administrative officer's review of the proposed development or
redevelopment. Applicants not meeting the requirements for an exemption
may apply or reapply for a different type of storm water permit(s)
according to the provision of this Chapter.
[R.O. 2007 §31½-5; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
Establishment Of Storm Water Management Fund.
1.
The storm water management program is established to protect the
waterways and land in the City by controlling flooding and to protect
the natural environment. In order to provide revenue to fund the costs
of the storm water management program and to fairly allocate those
costs, a Storm Water Management Fund ("the fund") is established.
2.
All revenues from grants, permit application fees, in lieu fees and
other charges collected under the storm water management regulations
ordinance shall be deposited to the fund. The Council may make additional
appropriations to the fund. All disbursements from the fund shall
be for the purposes of the fund as set forth hereinafter.
B.
Purpose. The fund shall be used for the following purposes:
1.
The acquisition by gift, purchase or condemnation of real and personal
property and interests therein necessary to construct storm water
control facilities.
2.
Engineering and design, easement acquisition, debt service and related
financing expenses, construction costs for new facilities and enlargement
or improvement of existing facilities.
3.
Other activities which are reasonably required.
[R.O. 2007 §31½-6; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
Purpose. The purpose of the storm water permit and storm
water management review process is to provide an organized framework
for evaluating and acting upon proposals for development as they relate
to storm water management issues.
B.
Required Information. It is the responsibility of an applicant
to include sufficient information in the storm water permit application
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. The applicant shall furnish the administrative officer with
the storm water permit application form and three (3) copies of the
storm water management plan documents sealed by a professional engineer
registered in the State.
C.
Minimum Information. The application form requires the following
minimum information:
1.
Type of permit applied for.
2.
Name of the project and legal description of the property.
3.
The name, address and telephone number of the applicant and the owner
if different from the applicant.
4.
Name and address of the professional engineer, unless applying for
an exemption.
5.
List of any additional permits necessary, applied for, approved or
denied including, but not limited to, Corps of Engineers Section 404
Permit, Missouri Department of Natural Resources 401 Permit, FEMA
Engineer's Certification of "No-Rise" and/or any other applicable
permits necessary and related to storm water or flood plain development.
E.
Storm Water Permit Application Standard Form. The applicant
shall provide all information as required by this regulation and requested
on the City storm water permit application standard form.
[R.O. 2007 §31½-7; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
A storm
water management plan is designed to safely manage the storm water
runoff following the rainstorms that exceed the maximum allowable
release rate and the capacity of the storm water drainage system and/or
the storm sewer system by detention of the excess storm water runoff.
The plan shall provide or be accompanied by map(s) and/or drawing(s)
at a minimum scale of one (1) inch less than or equal to two hundred
(≤ 200) feet and other descriptive material, including the
basis of computation, showing the following.
B.
Map/Drawing Requirements. (Note: Map scales are minimums.)
1.
Existing conditions information. Required existing
site information:
a.
Detailed location preliminary showing the parcel and major adjacent
roads.
b.
Topographic map of the site at a scale of one (1) inch less than
or equal to two hundred (≤ 200) feet with maximum five (5)
foot contour intervals, except in flood plains or other areas of low
relief where a smaller interval may be required.
c.
Where percolation or infiltration systems are proposed, information
as to the location and type or vegetative cover and soil types and
characteristics representative of the design condition mapped at a
scale of one (1) inch 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 flood plains at the established high
water elevations and the limits of the floodway mapped at a scale
of one (1) inch less than or equal to two hundred (≤ 200) feet.
e.
Location of lakes, ponds, swamps and detention basins indicating
their normal shorelines, flood plains and lines of inflow and outflow
mapped at a scale of one (1) inch 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 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, drainage ways, etc., which are potentially
directly affected by the proposed construction or development mapped
at a scale of one (1) inch less than or equal to two hundred (≤
200) feet.
2.
For all existing drainage facilities that are to be maintained, altered
or enlarged as part of the storm water 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.
Information on proposed developments.
a.
Location of all new drainage facilities, including detention basins,
to be constructed. Provide design details on each facility as applicable.
b.
Location of temporary erosion control measures, including silt fencing,
temporary ditching, check dams and any other temporary erosion control
measures necessary to prevent pollution of runoff during construction.
c.
Location and extent of existing and proposed impervious surfaces
(roads, parking lots, building, etc.) and their elevations. Provide
grading and paving drawing(s) and specifications.
d.
Location and extent of rights-of-way and easements for the storm
water management system, including all areas to be dedicated for water
management purposes.
C.
Additional Information Required.
1.
Identification and description of any special or required maintenance
procedures to keep the project functioning as designed.
2.
Provide storm water management system design calculations as follows:
a.
Design storms used.
b.
Calculated hydrographs of inflow and outflow of design storm runoff
for the project site under predeveloped conditions.
c.
Hydrographs of the runoff from the design storm for the project site
under developed conditions.
d.
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.
f.
Other data requested by the administrative officer.
g.
Runoff routing calculation showing discharge, elevations and volumes retained and/or detained during applicable storm event as required in Section 425.140.
h.
Calculations required for determination of minimum building floor
and road elevations.
3.
Identify the entity responsible for operation and maintenance of
the system.
D.
The
administrative officer upon written supportive recommendation of the
City Engineer or other designated official may waive the requirements
for specific plan elements cited above. The storm water management
plan for minor development activities may consist of a certification
from a professional engineer that the differential runoff equals zero.
[R.O. 2007 §31½-8; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
Storm Water Conveyance Systems. No waivers shall be approved
for storm water conveyance systems. All new or redevelopments shall
provide for an on-site storm water conveyance system to carry runoff
from the developed site and any pass through runoff from upper reaches
of the drainage basin.
B.
New Development. Waivers for storm water detention systems
may be approved for new developments where adequate justification
can be provided showing that the post development runoff is less than
or equal to the predevelopment runoff.
C.
Redevelopment Of Existing Sites.
1.
Additional storm water detention on sites currently permitted and meeting the storm water management plan requirements may be waived if the redevelopment does not affect more than one thousand (1,000) square feet and does not adversely affect any existing storm water facilities. If the redevelopment involves more than one thousand (1,000) square feet of area, the applicant shall submit a new storm water management plan with accompanying documentation per Section 425.070 or an "in lieu" fee per Section 425.090.
2.
Upon completion of any redevelopment with waived storm water detention,
the developer shall submit to the administrative officer certification
that the existing storm water facilities were not adversely affected.
Certification shall be sealed by a professional engineer registered
in the State of Missouri.
D.
Waiver Submittal Requirements. The following must be submitted
with the storm water management permit application to be considered
for a waiver:
2.
Location of temporary erosion control measures, including silt fencing,
temporary ditching, check dams and any other temporary erosion control
measures necessary to prevent pollution of runoff during construction.
3.
Location and extent of existing and proposed impervious surfaces
(roads, parking lots, building, etc.) and their elevations. Provide
grading and paving drawing(s) and specifications.
4.
Location and extent of rights-of-way and easements for the storm
water management system, including all areas to be dedicated for storm
water management purposes.
E.
Identification
and description of any special or required maintenance procedures
to keep the project functioning as designed.
G.
Identify
the entity responsible for operation and maintenance of the storm
water system.
[R.O. 2007 §31½-9; Ord. No. 6659 §2(Exh. A), 10-20-2003]
A.
General. Developments may be eligible to pay a fee in lieu
of providing storm water detention facilities for all or portions
of the required storage if the proposed site meets the following:
1.
City determines that the proposed improvements will have no major
impact on downstream storm water facilities or watercourses.
2.
City determines that the limited relief on the site or other natural
conditions of the site makes development of storm water detention
facilities ineffective or uneconomical.
B.
Storm Water Conveyance Systems. This Section applies only
to storm water detention facilities. Storm water conveyance systems
shall not be eligible for payment of a fee in lieu of constructing
storm water conveyance systems.
C.
Submittal Requirements. Along with the storm water management
permit application form, include the following:
1.
Existing and proposed site information as required in Section 425.070(B) — (C).
2.
Calculations as follows:
D.
Identify
the entity responsible for operation and maintenance of the system.
[R.O. 2007 §31½-10; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
General. Developments may be eligible to mitigate storm
water detention facilities if the proposed site meets the following:
1.
The mitigated facilities are located within the same drainage area
upstream of the project site or downstream and adjacent to the project
site.
2.
City determines that the proposed improvements will have no major
adverse impact on downstream storm water facilities or watercourses.
3.
City determines that the limited relief on the site or other natural
conditions of the site makes development of storm water detention
facilities ineffective or uneconomical.
B.
Storm Water Conveyance Systems. This Section applies only
to storm water detention facilities. Mitigation of storm water conveyance
systems shall not be considered.
C.
Submittal Requirements. All submittal requirements of Section 425.060 shall be necessary for both the project site and the site of mitigated detention facilities and any additional information deemed necessary by the administrative officer to ascertain the completeness and adequacy of the mitigated facilities and the impact on downstream storm water facilities and watercourses of both the project site and the site of mitigated detentions facilities.
D.
Identify
the entity responsible for operation and maintenance of both the project
site storm water management systems and the mitigated storm water
management systems.
[R.O. 2007 §31½-11; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
B.
Application
fee payment shall be due at the time the application is submitted
to the City for review. No review or consideration will be given until
the correct application fee has been paid in full.
C.
All
storm water management plan documents (excluding applications for
exemption) shall be prepared under the direction of a professional
engineer prior to the submission of the storm water management permit
application to the City. All fees for such review and evaluation shall
be paid by the property owner or developer directly to the engineer
and the engineer shall certify that he/she has reviewed the proposed
storm water management plan documents and that said plan documents
conform with all design requirements and other requirements imposed
by this Chapter.
D.
In-lieu
of detention fees shall be based on the volume of storage required
as determined according to this regulation. In-lieu fees shall be
as follows:
1.
Up to fifteen thousand (15,000) cubic feet of required storage: Sixty
cents ($0.60) per cubic foot.
2.
Fifteen thousand (15,000) to thirty-five thousand (35,000) cubic
feet of required storage: Forty-five cents ($0.45) per cubic foot.
3.
Thirty-five thousand (35,000) to sixty-five thousand (65,000) cubic
feet of required storage: Thirty cents ($0.30) per cubic foot.
4.
Over sixty-five thousand (65,000) cubic feet of required storage:
Twenty cents ($0.20) per cubic foot.
E.
In-lieu
of detention fee payment shall be due upon completion and approval
of the in-lieu of detention storm water management permit. Building
permits will not be issued for a site until the in-lieu of detention
fee has been paid in full.
F.
The administrative officer will ascertain the completeness of the storm water management permit application. The administrative officer will return incomplete applications to the applicant for completion and resubmission. After determining that the application is complete, the administrative officer will distribute copies of the application for review and comment to other persons with special technical expertise as deemed appropriate by the administrative officer. Within twenty-one (21) business days after submission of the complete storm water management permit application by the applicant, unless review by an outside consultant is required, the administrative officer shall approve, approve with specified conditions, request additional information/clarification or deny the application and shall notify the applicant accordingly. If the storm water management permit application is denied or approved with conditions, the administrative officer shall state the reasons for denial or the specified conditions. If review by an outside consultant is required, the administrative officer shall notify the applicant of the outside review and shall respond to applicant within ten (10) business days of receiving a final report from the consultant. If the applicant feels aggrieved due to the denial or conditions, he/she may appeal the decision according to the provisions established in Section 425.200 (B).
G.
In
addition to the application fee as denoted above, an additional fee
equal to the original application fee may be charged for excessive
submittals. The term "excessive submittals" is defined
as three (3) or more resubmittals on the same project based on review
comments by the City.
[R.O. 2007 §31½-12; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
A storm
water management system shall be provided for protecting lots, roads,
streets and buildings in the project area from the potential adverse
impacts of storm water 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
storm waters into the ground and to preserve and utilize natural streams,
channels and detention basins and, whether possible, to include streams
and flood plains within parks or other public grounds.
B.
Minimum Detention Volume. The increased storm water runoff
resulting from the proposed development shall be detained on-site
by appropriate detention structures. The minimum volume of storage
shall be sufficient to store the volume from a 25-year storm under
the proposed developed conditions. Acceptable detention structures
shall include dedicated storm water detention basins; storage on flat
roofs, parking lots or streets; or by other acceptable techniques
approved by the administrative officer. Control devices shall be incorporated
to regulate discharge from storage in accordance with the provisions
of this Chapter.
C.
Maximum Allowable Release Rate. The maximum allowable release
rate of storm water after development shall not exceed the before-development
rate for each rainfall event considered. Downstream property, watercourses,
channels or conduits shall not receive storm water runoff from proposed
development at a higher peak flow rate than that which existed prior
to the development.
D.
Primary Outlet Release Rate. Detention basin control structures
shall be designed to release runoff at a flow rate not to exceed ninety
percent (90%) of the peak flow rate calculated for a 25-year frequency
storm, under predevelopment conditions, when the detention basin water
level is equal to the level required to store the minimum detention
volume. This flow rate shall be defined as the primary outlet release
rate. The primary outlet release rate shall not be exceeded prior
to detaining one hundred percent (100%) of the minimum detention volume
in storage.
E.
Low Flow Release Rate. The detention basin control structure
shall further be designed to limit the release rate of storm water
during low-flow conditions. The "low flow release rate" shall be defined as twenty-five percent (25%) of the peak flow rate
calculated for a 25-year frequency storm, under predevelopment conditions,
based on a 25-year frequency storm. The low flow release rate shall
not be exceeded prior to detaining fifty percent (50%) of the minimum
detention volume
F.
The
total drainage area must be used in calculating the release rates.
The required storage volume will be based on the project area only.
Extraneous flows from upland areas shall be by-passed or discharged
via overflow spillway or other devices.
G.
Generally
acceptable locations of the storm water runoff channels in the design
of the project area may include the following:
1.
In a depressed median of a double roadway, street or parkway provided
the median is wide enough to permit required roadway shoulders.
2.
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.
3.
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.
H.
Alternative
systems such as curb and gutter and storm sewers that discharge into
an appropriate detention basin may be incorporated into the storm
water management plan.
I.
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.
J.
A continuous easement may be provided abutting rear lot lines as shown in the storm water management plan drawing(s) 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 as specified in Section 425.160. 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 contour of the specified floodwater or storm water runoff channels.
K.
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 back-ups into planned storage locations.
L.
All
sanitary sewer manholes constructed in a flood plain, in a street
designed to provide detention or in an area designed for the storage
for passage of floodwater or storm water shall be provided with either
a water-tight bolted manhole cover, a water-tight 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.
No sanitary sewer manholes shall be constructed in an area designated
for storm water detention where other feasible locations exist.
M.
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.
[R.O. 2007 §31½-13; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
Design Storms. Storm water systems will be designed with
sufficient hydraulic capacity as a minimum for the following frequencies
and durations:
|
Type of Facility
(Year)
|
Design Frequency Year
|
|---|---|
|
Detention storage
|
100
|
|
Detention basin overflow
|
100
|
|
Primary drainage systems
|
100
|
|
Bridges
|
100
|
|
Secondary drainage systems (i.e., cross drains and ditches for
internal subdivision drainage)
|
25
|
B.
The
administrative officer may require alternative designs or features
to reduce the cost of long-term maintenance.
C.
In
critical areas, the administrative officer may require additional
hydraulic capacity above the minimum set forth above.
[R.O. 2007 §31½-14; Ord. No.
6659 §2(Exh. A),10-20-2003; Ord. No. 23-01, 1-17-2023]
A.
Method Of Evaluation. Differential runoff evaluation consists of
the determination of rates of runoff before and after development,
the determination of required volume of detention and verification
of adequacy of discharge and control structures. At a minimum all
design requirements shall apply to all sites that disturb one (1)
acre or more or are part of a larger common development that will
disturb one (1) acre or more.
B.
Differential Runoff Rates. Differential runoff rates for all three
(3) size classes of projects shall be evaluated by the rational formula.
The runoff coefficients in Table II shall be used. Differential runoff
rates shall be evaluated by equation:
|
R = (Rd-Ru) (EQUATION 1)
| ||
|
Where:
| ||
|
R
|
=
|
Differential runoff rate
|
|
Rd
|
=
|
CI factor for developed conditions
|
|
Ru
|
=
|
CI factor for undeveloped conditions
|
C.
Volume Detention. Volumes of detention for the three (3) classes
of projects shall be evaluated according to the following methods:
1.
Volume of detention for projects of less than twenty-five (25)
acres shall be evaluated by the "Simplified Volume Formula."
2.
Volume of detention for projects of twenty-five (25) acres or
greater but less than two hundred (200) acres may be evaluated either
by the "simplified volume formula" or the "Modified Rational Hydrograph
Method."
3.
For projects larger than two hundred (200) acres, the owner's
engineer shall submit his/her proposed method of evaluation for the
sizing of the detention basin to the administrative officer. The method
will be evaluated for professional acceptance, applicability and reliability.
No detailed review for projects larger than two hundred (200) acres
will be rendered before the method of evaluation of the detention
is approved.
4.
Other analytical methods of evaluation of volume of detention
will be considered, provided that reliability, professional acceptance
and proper application are approved by the administrative officer.
D.
Formulae. Any of the following methods may be used for calculating
detention volume as applicable:
1.
Simplified Volume Formula. Total volume of detention shall be
computed by the equation:
|
V = R x A x 30 (min) x 60 (see/min) (EQUATION 2)
| ||
|
Where:
| ||
|
V
|
=
|
Total volume of detention
|
|
R
|
=
|
Differential runoff rate
|
|
A
|
=
|
Area of project in acres
|
2.
Graphic Representation. For purposes of further analysis, the Simplified Volume Formula may be represented by a triangular synthetic hydrograph as shown in Figure 1 (following Section 425.270) with the following elements:
|
Tb = Base time of hydrograph for developed project without detention
|
|
Tb = 60 minutes
|
|
Tp = Time of peak runoff of developed project
|
|
Tp = 20 minutes
|
|
Qd = Total peak runoff of developed project in cfs.
|
|
Qd = A x Rd (see equation 1)
|
|
Qu = Total peak runoff of unimproved project in cfs.
|
|
Qu = A x Ru (see equation 1)
|
|
A = Total area of project in acres
|
|
Tq = Assumed time of peak differential for unimproved project
|
|
Tq = Qu/Qd x 40
|
|
Tr = Assumed recedence time differential for discharge at rates
no greater than unimproved condition
|
|
Tr = (30 Qd/Qu) - 60
|
|
V = Volume of detention
|
|
V = (Qd-Qu) x 30 (min) x 60 (sec/min)
|
3.
Modified Rational Hydrograph Method. This is a modification of the unit hydrograph method of hydrologic evaluation simplified to reflect features of present practice and some elements of topographic characteristics, concentration patterns and routing. Figure 1 (following Section 425.270) illustrates the elements of the modified hydrograph. Steps to develop the hydrograph are as follows:
a.
Determine the time of concentration for the project by use of Figure 2 (following Section 425.270) or similar reference manual adopted by the City Engineer or other designated official. Figure 2 is based on overland flow time from Seeley Data Book for Civil Engineers. Enter chart with overland travel distance; follow horizontally to slope curve then vertically down to C or P factor listed in Table II and obtain Tc. For analysis of large improved channels, time for travel for overland flow and channel are to be analyzed to determine reasonable (Tc) time of concentration.
b.
Determine time of peaking by equation:
|
Tp = D/2 + 0.6 Tc (EQUATION 3)
| ||
|
Where:
| ||
|
Tp
|
=
|
Time of peak discharge of developed project in minutes
|
|
D
|
=
|
20 minutes = storm duration in minutes
|
c.
Determine the base time of the hydrograph without detention
by equation:
|
Tb = 2.67 Tr; (EQUATION 4)
|
d.
Determine the base time of the hydrograph with detention by
equation:
|
Tr = Tb (Qd/Qu - 1) (EQUATION 5)
| ||
|
Where:
| ||
|
Tr
|
=
|
Additional time required for discharge at a rate no greater
than that of the undeveloped condition:
|
|
Qd
|
=
|
Total peak runoff of improved project in cfs.
|
|
Qd
|
=
|
A x Rd (see equation 1) (EQUATION 6)
|
|
Qu
|
=
|
Total runoff of unimproved project in cfs
|
|
Qu
|
=
|
A x Ru (see equation 1) (EQUATION 7)
|
e.
Determine the required volume of detention by equation:
|
V = 1/2 (Qd - Qu) Tb (EQUATION 8)
|
E.
Control Structures. Detention facilities shall be provided with obvious
and effective control structures. Plan view and sections of the structure
with adequate detail shall be included in the drawing(s). Provision
shall be made to protect clogging of outlets by debris and/or silt.
Access to control structures shall be provided for maintenance and
inspection. Control structures shall be designed to regulate water
discharges at the primary outlet discharge rate and the low-flow discharge
rate. A rating table recording the relationship among detention facility
water elevation, stored volume and discharge flow rate shall be provided
on the drawing(s) clearly indicating the numeric values at the two
(2) design flow rates.
F.
Design discharges for the outlet structure(s) shall be as follows:
1.
Primary Outlet Discharge Rate. The primary outlet discharge
rate shall be calculated as ninety percent (90%) of the peak flow
rate determined for a rainfall event (storm) having a twenty-five-year
return frequency, with a duration equal to the time of concentration
for the drainage basin watershed, under predevelopment conditions
[five percent (5%) imperviousness]. The primary outlet discharge rate
shall not be exceeded prior to the detention structure detaining one
hundred percent (100%) of the minimum detention volume.
2.
Low Flow Release Rate. The low flow release rate shall be calculated
as twenty-five percent (25%) of the peak flow rate determined for
a rainfall event (storm) having a twenty-five-year return frequency,
with a duration equal to the time of concentration for the drainage
basin watershed, under predevelopment conditions [five percent (5%)
imperviousness]. The low flow discharge rate shall not be exceeded
prior to the detention structure detaining fifty percent (50%) of
the minimum detention volume.
3.
When emergency overflow structures are combined with control
structures, the control structure shall be sized to safely pass the
one-hundred-year flood under current runoff conditions, but not less
than thirty-five percent (35%) impermeable for the entire drainage
area considered. The overflow opening or spillway shall be designed
to accept the total peak runoff of the improved tributary area. Consideration
shall be given to anticipated land use upstream of the control structure
when determining the peak one-hundred-year flood runoff.
G.
Detention Design Criteria. Detention in the overall system, including
swales, lakes, canals, greenways, etc., shall be provided as follows.
1.
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 from a twenty-five-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. Outlet control structures shall be designed to safely discharge flows no greater than the primary outlet release defined in Section 425.120(D) and when the basin water level is at the twenty-five-year storm level.
c.
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 one-hundred-year storm.
d.
Low Flow Channel. The low flow channel invert through dry detention
facilities on other than permanently flowing streams shall be paved.
e.
Designs should result in aesthetically pleasing configurations
which will enhance public acceptability.
2.
Dry Detention Facilities.
a.
Perimeter maintenance easements of fifteen (15) feet (minimum)
width at slopes no steeper than 3:1 (horizontal to vertical) shall
be provided.
b.
Vegetated side slopes of the facility shall not be steeper than
3:1 (horizontal to vertical). Paved side slopes steeper than 3H:1V
or retaining walls may be allowed provided that adequate safety precautions
are provided around the entire perimeter. Paved slopes shall be designed
to eliminate vegetation growth and minimize cracking.
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.
Multi-purpose 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 be
closer than twenty-five (25) feet horizontally from any building and
less than two (2) feet vertically below the lowest sill elevation.
The entire reservoir area shall be seeded, fertilized and mulched,
sodded or paved.
3.
Wet Detention Facilities.
a.
Perimeter maintenance and operation easements of fifteen (15)
feet (minimum preferable) width at slopes no steeper than 3:1 (horizontal
to vertical) shall be provided.
b.
Control elevations should be no higher than two and one-half
(2 1/2) 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.
Vegetated side slopes shall not be steeper than 3:1 (horizontal
to vertical) out to a depth of two (2) feet below the control elevation,
then as steep as soil 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.
The limits of maximum ponding elevations are to be no closer
than twenty-five (25) feet horizontally from any building and no less
than two (2) feet below the lowest sill elevation of any building.
4.
Impervious Areas. Paved parking lots may be designed to provide
detention storage of storm waters on all or a portion of their surfaces.
Outlets will be designed so as to slowly empty the stored waters and
depths of storage must be limited to a maximum depth of twelve (12)
inches so as to prevent damage to parked vehicles. Ponding should
be regulated to those portions of the parking lots farthest from the
area served.
5.
Rooftop Storage. Detention storage requirements may be met in
total or in part by detention of flat roofs. Details of such designs,
to be included in the storm water management permit application, shall
include the depth and volume of storage, details of outlets devices
and down- drains, elevations of overflow scuppers, design loadings
for the roof structure and emergency overflow provisions.
6.
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 and ground water pollution control.
7.
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.
H.
Developments Adjoining A Flood Plain. Where a development adjoins
or encompasses a portion of a flood plain for a one-hundred-year flood,
the following shall apply:
1.
The applicant shall show the flood plain and floodway on the
storm water management plan.
2.
The applicant shall include in the storm water management plan
all other drawing(s), plats, specifications, etc., required by Federal,
State, County and/or municipal law or regulations detailing such provisions
or restrictions as are necessary to comply with the following:
I.
Alterations Affecting Flow. The applicant shall not alter any channel
from conveying, in its post-development state, the same amount of
flow, at the same or lower maximum water elevation that is conveyed
in its predevelopment state.
J.
Additional Information. The applicant shall furnish, for the administrative
officer's review and approval, the following information pertaining
to proposed channel modifications:
1.
Typical cross sections of the existing and proposed channel.
2.
Plan view of the channel showing the location of existing constrictions,
obstructions and other non-typical areas.
3.
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.
4.
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.
5.
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. "Flood Insurance Rate Map" published by the Federal
Emergency Management Agency; or backwater curve profiles of the proposed
waterway due to a one-hundred-year storm recurrence interval.
6.
Designation on the final plan view drawing(s) 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.
K.
Credit For Detention Storage. If detention storage is provided within
a flood plain, only the net increase in storage volume above that
which naturally existed on the flood plain shall be credited to the
development. No credit will be granted for volumes below the elevation
of the regulatory flood at the location unless compensatory storage
is also provided.
L.
Verification Of Adequacy. Analysis of all elements of design is to
be verified by the engineer of record submitting the storm water management
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:
1.
Volume of detention for the total project;
2.
Tributary (Q) peak runoff to basin;
3.
Balanced maximum outflow rate from the low-flow structure;
4.
Ratios of inflow to outflow rates;
5.
Sizing of the overflow facilities;
6.
Stability of detention dikes;
7.
Safety features;
8.
Maintenance features.
M.
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.
N.
Projects
over two hundred (200) acres in area shall provide documented verification
of adequacy according to scope and complexity of design.
|
TABLE II. AVERAGE CI (PI) FACTORS IN CFS PER ACRE 20-MINUTE
INLET TIME
| ||||
|---|---|---|---|---|
|
Impervious Area (Percent)
|
C Or P Factor
|
25-Year
|
50-Year
|
100-Year
|
|
5
|
0.370
|
2.15
|
2.39
|
2.63
|
|
10
|
0.390
|
2.26
|
2.52
|
2.77
|
|
15
|
0.410
|
2.38
|
2.64
|
2.91
|
|
20
|
0.435
|
2.52
|
2.81
|
3.09
|
|
25
|
0.455
|
2.64
|
2.93
|
3.23
|
|
30
|
0.475
|
2.76
|
3.06
|
3.37
|
|
35
|
0.495
|
2.87
|
3.19
|
3.51
|
|
40
|
0.520
|
3.02
|
3.35
|
3.69
|
|
45
|
0.540
|
3.13
|
3.48
|
3.83
|
|
50
|
0.560
|
3.25
|
3.61
|
3.98
|
|
55
|
0.580
|
3.36
|
3.74
|
4.12
|
|
60
|
0.600
|
3.48
|
3.87
|
4.26
|
|
65
|
0.625
|
3.63
|
4.03
|
4.44
|
|
70
|
0.645
|
3.74
|
4.16
|
4.58
|
|
75
|
0.665
|
3.86
|
4.29
|
4.72
|
|
80
|
0.685
|
3.97
|
4.42
|
4.86
|
|
85
|
0.705
|
4.09
|
4.55
|
5.01
|
|
90
|
0.730
|
4.23
|
4.71
|
5.18
|
|
95
|
0.750
|
4.35
|
4.84
|
5.33
|
|
100
|
.770
|
4.47
|
4.97
|
5.47
|
|
Rainfall
|
5.80
|
6.45
|
7.10
| |
|
From Midwestern Climate Center Research Report 93-03, Bulletin
71: "Rainfall Frequency Atlas of the Midwest" by Floyd A. Huff and
James R. Angel, 1992.
|
O.
Installation Of Storm Water Runoff Control Measures. Positive storm
water runoff control shall be provided for during development. Storm
water 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
storm water management plan drawing(s). Installation of drainage facilities
and erosion control measures shall proceed as scheduled in the approved
storm water management plan. The development shall develop post construction
Best Management Practices (BMP's) to minimize water quality impacts
by use of structural and/or non-structural controls and comply with
the Missouri Department of Natural Resources Land Disturbance Permit
and the City's Municipal Separate Storm Sewer System Permit (MS4s).
P.
Pre-Construction Plan Review. A preconstruction meeting to review
both construction erosion control (BMPs) and post construction controls
(BMPs) that shall be in place at the end of construction. As part
of this meeting long term operation and maintenance (O&M) of the
selected BMPs will also be discussed.
Q.
Post Construction Site Review. A post-site visit shall be completed
to ensure compliance with the approved plan prior to issuing an occupancy
permit.
R.
Operating and Maintenance. The owner/developer shall be responsible
for the short and long-term O&M during construction and post construction
to reduce water quality impacts. Owner or developer shall submit an
O&M Plan with the stormwater management plan to address long-term
maintenance procedures. Annual inspections shall be conducted by the
owner or developer and report provided to the City for review. The
City may selectively inspect a development and issue notices to the
owner if corrective measures are required. Owner will be required
to perform corrective actions or be subject sanctions to the extent
allowable under State and local law.
[R.O. 2007 §31½-15; Ord. No.
6659 §2(Exh. A), 10-20-2003; Ord. No. 23-01, 1-17-2023]
A.
Design Requirements For Soil Erosion Control During Construction.
1.
A soil erosion control plan shall accompany all permit site
applications with land disturbances greater than or equal to one (1)
acre or less than one (1) acre if the construction activity is part
of a larger common plan or development that would disturb one (1)
acre or more. The purpose of the plan is to clearly establish what
measures will be taken to prevent erosion and off-site sedimentation
during construction development. The soil erosion control plan or
Stormwater Pollution Prevention Plan (SWPPP) shall consist of two
(2) parts:
a.
Site grading and drainage drawing(s); and
b.
Narrative report describing the nature and scope of the work,
report may be incorporated into the plan. The plan shall be prepared
and certified by a registered professional engineer licensed in the
State of Missouri. Applicant should also submit a copy of the Missouri
Department of Natural Resources Land Disturbance permit as part of
their plan.
2.
All surfaces must be stable and non-erosive within the lesser
of thirty (30) working days or sixty (60) calendar days after completion
of the work authorized by the permit for a storm water management
plan. When such work is associated with the construction of a building,
no certificate of occupancy shall be issued until such surfaces are
stable and non-erosive. If completion of the work or building is at
such time of the year that stabilization with ground cover is not
possible, a performance bond or other acceptable financial instrument
for completion of the work may be accepted to allow the issuance of
a certificate of occupancy. The amount of the bond shall be equal
to the cost to complete the work as determined by the City administrative
officer.
3.
Grading, erosion control practices, sediment control practices
and waterway crossings shall meet the design criteria set forth in
the most recent version of "Protecting Water Quality - A Field Guide
to Erosion, Sediment and Storm Water Best Management Practices for
Development Sites in Missouri and Kansas" (as provided by the Missouri
Department of Natural Resources) and shall be adequate to prevent
transportation of sediment from the site to the satisfaction of the
administrative officer.
B.
Site Grading And Drainage Drawing(s).
1.
The site grading and drainage drawing(s) shall include the following:
a.
Existing Features.
(1)
A drainage area map showing topography of the entire
drainage basin(s) contributing to the site. The scale of the map shall
be no smaller than one (1) inch equals two hundred (200) feet for
drainage areas up to five hundred (500) acres. The drainage map is
to show total acreage of the site and the acreage of all drainage
areas contributing to the site.
(2)
A site plan drawing(s) having a scale no smaller
than one (1) inch equals one hundred (100) feet and existing contour
intervals of not more than five (5) feet. The drawing(s) shall show
topographic features such as highways, utilities, natural watercourses,
existing drainage facilities and structures, adjacent property lines,
north arrow, scale and vicinity map. The site plan drawing(s) shall
also show the limits of the one-hundred-year flood plain on the site
and any critical environmental areas such as streams, lakes, ponds
and wetlands. Area and geological types of predominant soils as well
as the nature and extent of existing vegetation shall also be shown
on the drawing(s).
b.
Proposed Alterations Of The Site.
(1)
A grading plan drawing(s) that shows the limits
of clearing and grading, cuts and fills and final contours at not
more than two (2) feet intervals. The drawing(s) shall identify the
phasing of the grading, showing the area(s) to be denuded and the
maximum time those areas will remain disturbed [not to exceed the
lesser of thirty (30) working days or sixty (60) calendar days after
completion of the work]. The drawing(s) shall show areas to be used
for storage of topsoil and excavated subsoil and plans for access
to the site during wet weather.
(2)
A final site plan drawing(s) showing the location
or relocation of all utilities, planned streets, roads, buildings,
parking lots and structures and all permanent storm water management
facilities.
(3)
Temporary Erosion And Sediment Control Measures
During Active Construction.
Drawings shall be provided showing types of erosion and sediment
control measures and facilities needed and the location of those measures
and facilities with dimensional details. All permanent deviations
in overland flow drainage patterns and the location of ingress and
egress points with the planned protection provisions are to be indicated.
c.
Narrative Report To Be Submitted Upon Request From The Administrative
Officer. The narrative report describing the nature and scope of the
work shall include the following:
(1)
The report shall briefly describe the overall project
and shall incorporate an explanation of existing significant drainage
problems contributing to erosion and siltation problems, particularly
those that will be intensified by alteration of the site due to construction.
(2)
Explanations for the selection of the soil erosion
control measures to be utilized shall be provided.
(3)
The phasing or staging of development activities
that will disturb the land is to be described, including information
on the sequence of the work; specifying the maximum area and time
span that each area will be left denuded; the provisions for the removal,
protection and stockpiling of soil; the types of major earth moving
and grading activities; dust control measures; and the order of placement
of control facility installations.
(4)
A schedule shall be provided for inspection and
maintenance of the temporary soil erosion and sediment control measures
to insure maximum effectiveness and to assure that maintenance efforts
will be carried out when needed. The report should also include a
description of the disposal of temporary structural measures after
they have served their purpose.
(5)
A description of permanent erosion and sediment
control measures, including plans for resodding or reseeding of vegetated
areas and repair or reconstruction of damaged structural measures.
d.
Grading And Pavement Permits. No permit for grading or constructing
any public street shall be issued until the temporary erosion control
measures set forth in the site grading and drainage plan have been
properly installed.
e.
Temporary Erosion Control Measures. The temporary erosion control
measures described in the site grading and drainage plan shall be
properly installed prior to commencement of any construction or land
disturbance activity and shall be properly maintained at all times
until all land surfaces on the property become stable and non-erosive.
[R.O. 2007 §31½-16; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
All
storm water management facilities shall be constructed within an easement
or right-of-way dedicated for storm water management use and connected
to a public road or other location from which operation and maintenance
are 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. The minimum widths of rights-of-way
and easements shall be as follows:
|
Facility
|
Maintenance Access Width
|
|---|---|
|
Open drainage channel or facilities
|
30 feet, 15 feet each side
|
|
Greenways
|
Width of greenway
|
|
Pipes and culverts
|
15 feet centered
|
|
Detention areas
|
15 feet continuous around total area
|
|
Connecting areas
|
15 feet
|
B.
Easements
must include the "top of the bank width" and the maintenance access
width.
C.
The
maintenance access width begins at the point of the bank or slope
of the facility.
D.
The
maintenance access width may be required by the administrative officer
in special circumstances where more width on one (1) or both sides
is necessary for maintenance purposes.
E.
Deed
restrictions shall be provided for subdivision lots to restrict use
of land designated for storm water detention facilities and drainage
facilities.
F.
Recorded
subdivision plots shall detail all easements and deed restricted areas.
G.
All
lots within a subdivision that contain all or part of an area designated
for storm water management shall have a deed recorded prior to issuing
a building permit, which includes a detailed deed restriction for
the designated area. Deed restrictions shall include the following
as a minimum:
1.
Description of restricted area.
2.
Prohibit any activity that results in a reduction in the storage
volume of the detention basin or that results in an increase to the
discharge from the outlet works.
3.
Prohibit building on restricted area.
4.
Prohibit any activity that will compromise the function of the storm
water management system.
5.
Prohibit modification to the outlet structure, other than modifications
to improve its aesthetic appearance (e.g., brick, signage, painting,
etc.).
[R.O. 2007 §31½-17; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
Purpose. The purpose of this Section is to establish maintenance
standards to ensure that, after storm water management facilities
have been properly designed and constructed, they continued to function
properly. Continued proper functioning is highly dependent upon the
proper maintenance of the facilities.
B.
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 administrative officer
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 and
minimizes future maintenance costs.
C.
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.
1.
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.
2.
The responsibility for maintenance of storm water 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 property, the maintenance
of storm water management facilities shall be vested with the owner
of the property.
3.
The responsibility for maintenance of storm water 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 owner 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. Storm water detention facilities and drainage facilities shall be designated on the subdivision plat and restricted for use only for its intended purpose. Prior to receiving a building permit, the owner or developer shall have a deed recorded in their name for all lots containing restricted areas for storm water detention facilities and drainage facilities. The recorded deed shall contain detailed deed restrictions per Section 425.160. A copy of the recorded deed shall be submitted to the City prior to obtaining a building permit.
4.
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
administrative officer. Copies of all agreements or covenants shall
be provided to the administrative officer.
5.
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 administrative officer.
6.
All storm water management system(s) shall have adequate easements,
dedicated to the public for storm water management use, to permit
the City to inspect and enter upon the property as necessary.
D.
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
one (1) year period following completion. Inspection and repair of
defects shall be required as a condition of release of the posted
security.
[R.O. 2007 §31½-18; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
The
applicant shall be required to adhere strictly to the storm water
management plan as approved. Any changes or amendments to the plan
must be approved by the administrative officer in accordance with
the procedures set forth in this Chapter for obtaining storm water
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.
B.
Engineer's Certification Of Construction. Upon completion
of construction of the entire storm water management system, the developer
shall provide written certification that the project has been completed
and constructed according to the storm water management plan as approved
by the City. Certification shall be sealed, signed and dated by an
engineer registered in the State of Missouri.
[R.O. 2007 §31½-19; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
Purpose.
1.
The purpose of this Chapter is to provide for the health, safety
and welfare of the citizens of the City of Poplar Bluff through the
regulation of non-storm water discharges to the storm drainage system
to the maximum extent practicable as required by Federal and State
law.
2.
This Chapter shall apply to all water entering the storm drain system
generated on any developed and undeveloped lands unless explicitly
exempted by the City administrative officer.
3.
This Chapter establishes methods for controlling the introduction
of pollutants into the municipal separate storm sewer system (MS4)
in order to comply with requirements of the National Pollutant Discharge
Elimination System (NPDES) permit process. The objectives of this
Chapter are:
a.
To regulate the contribution of pollutants to the municipal separate
storm sewer system (MS4) by storm water discharges by any user;
b.
To prohibit illicit connections and discharges to the municipal separate
storm sewer system; and
c.
To establish legal authority to carry out all inspection, surveillance
and monitoring procedures necessary to ensure compliance with this
Chapter.
B.
Responsibility For Administration. The City of Poplar Bluff
or its administrative officer shall administer, implement and enforce
the provisions of this Chapter. Any powers granted or duties imposed
upon the authorized enforcement agency may be delegated in writing
by the administrative officer to persons or entities acting in the
beneficial interest of or in the employment of the City.
C.
Ultimate Responsibility. The standards set forth herein
and promulgated pursuant to this Chapter are minimum standards; therefore
this Chapter does not intend nor imply that compliance by any person
will ensure that there will be no contamination, pollution, nor unauthorized
discharge of pollutants.
D.
Discharge Prohibitions.
1.
Prohibition of illegal discharges. No person shall
discharge or cause to be discharged into the municipal storm drain
system or watercourses any materials including, but not limited to,
pollutants or waters containing any pollutants that cause or contribute
to a violation of applicable water quality standards, other than storm
water. The commencement, conduct or continuance of any illegal discharge
to the storm drain system is prohibited except as described as follows:
a.
The following discharges are exempt from discharge prohibitions established
by this Chapter: water line flushing or other potable water sources,
landscape irrigation or lawn watering, diverted stream flows, rising
ground water, ground water infiltration to storm drains, uncontaminated
pumped ground water, foundation or footing drains (not including active
ground water dewatering systems), crawl space pumps, air-conditioning
condensation, springs, non-commercial washing of vehicles, natural
riparian habitat or wet-land flows, swimming pools (if dechlorinated,
typically less than one (1) PPM chlorine), fire-fighting activities
and any other water source not containing pollutants.
b.
Discharges specified in writing by the authorized enforcement agency
as being necessary to protect public health and safety.
c.
Dye testing is an allowable discharge, but requires a verbal notification
to the authorized enforcement agency prior to the time of the test.
d.
The prohibition shall not apply to any non-storm water discharge
permitted under an NPDES permit, waiver or waste discharge order issued
to the discharger and administered under the authority of the Federal
Environmental Protection Agency, provided that the discharger is in
full compliance with all requirements of the permit, waiver or order
and other applicable laws and regulations, and provided that written
approval has been granted for any discharge to the storm drain system.
2.
Prohibition of illicit connections.
a.
The construction, use, maintenance or continued existence of illicit
connections to the storm drain system is prohibited.
b.
This prohibition expressly includes, without limitation, illicit
connections made in the past, regardless of whether the connection
was permissible under law or practices applicable or prevailing at
the time of connection.
E.
Industrial Or Construction Activity Discharges. Any person
subject to an industrial or construction activity NPDES storm water
discharge permit shall comply with all provisions of such permit.
Proof of compliance with said permit may be required in a form acceptable
to the administrative officer prior to the allowing of discharges
to the municipal separate storm sewer system (MS4).
F.
Access To Facilities For Monitoring Discharges.
1.
Applicability. This Section applies to all facilities
that have storm water discharges associated with industrial activity,
including construction activity.
2.
Access to facilities.
a.
The administrative officer shall be permitted to enter and inspect
facilities subject to regulation under this Chapter as often as may
be necessary to determine compliance with this Chapter. If a discharger
has security measures in force, which require proper identification
and clearance before entry into its premises, the discharger shall
make the necessary arrangements to allow access to representatives
of the administrative officer.
b.
Facility operators shall allow the administrative officer ready access
to all parts of the premises for the purposes of inspection, sampling,
examination and copying of records that must be kept under the conditions
of a NPDES permit to discharge storm water and the performance of
any additional duties as defined by State and Federal law.
c.
The administrative officer shall have the right to set up on any
permitted facility such devices as are necessary in the opinion of
the administrative officer to conduct monitoring and/or sampling of
the facility's storm water discharge.
d.
The administrative officer has the right to require the discharger
to install monitoring equipment as necessary. The facility's sampling
and monitoring equipment shall be maintained at all times in a safe
and proper operating condition by the discharger at its own expense.
All devices used to measure storm water flow and quality shall be
calibrated to ensure their accuracy.
e.
Any temporary or permanent obstruction to safe and easy access to
the facility to be inspected and/or sampled shall be promptly removed
by the operator at the written or oral request of the administrative
officer and shall not be replaced. The costs of clearing such access
shall be borne by the operator.
f.
Unreasonable delays in allowing the administrative officer access
to a permitted facility is a violation of a storm water discharge
permit and of this Chapter. A person who is the operator of a facility
with a NPDES permit to discharge storm water associated with industrial
activity commits an offense if the person denies the administrative
officer reasonable access to the permitted facility for the purpose
of conducting any activity authorized or required by this Chapter.
g.
If the administrative officer has been refused access to any part
of the premises from which storm water is discharged and he/she is
able to demonstrate probable cause to believe that there may be a
violation of this Chapter or that there is a need to inspect and/or
sample as part of a routine inspection and sampling program designed
to verify compliance with this Chapter or any order issued hereunder
or to protect the overall public health, safety and welfare of the
community, then the administrative officer may seek issuance of a
search warrant from any court of competent jurisdiction.
G.
Requirements To Prevent, Control And Reduce Storm Water Pollutants
By BMPs. The administrative officer will adopt requirements
identifying best management practices for any activity, operation
or facility that may cause or contribute to pollution or contamination
of storm water, the storm drain system or waters of the U.S. The owner
or operator of a commercial or industrial establishment shall provide,
at their own expense, reasonable protection from accidental discharge
of prohibited materials or other wastes into the municipal storm drain
system or watercourses through the use of these structural and non-structural
BMPs. Further, any person responsible for a property or premise, which
is or may be the source of an illicit discharge, may be required to
implement, at said person's expense, additional structural and non-structural
BMPs to prevent the further discharge of pollutants to the municipal
separate storm sewer system. Compliance with all terms and conditions
of a valid NPDES permit authorizing the discharge of storm water associated
with industrial activity, to the extent practicable, shall be deemed
compliance with the provisions of this Section. These BMPs shall be
part of a Storm Water Pollution Prevention Plan (SWPPP) as necessary
for compliance with requirements of the NPDES permit.
H.
Watercourse Protection. Every person owning property through
which a watercourse passes, or such person's lessee, shall keep and
maintain that part of the watercourse within the property free of
trash, debris, excessive vegetation and other obstacles that would
pollute, contaminate or significantly retard the flow of water through
the watercourse. In addition, the owner or lessee shall maintain existing
privately owned structures within or adjacent to a watercourse, so
that such structures will not become a hazard to the use, function
or physical integrity of the watercourse.
I.
Notification Of Spills.
1.
Notwithstanding other requirements of law, as soon as any person
responsible for a facility or operation or responsible for emergency
response for a facility or operation has information of any known
or suspected release of materials which are resulting or may result
in illegal discharges or pollutants discharging into storm water,
the storm drain system or water of the U.S., said person shall take
all necessary steps to ensure the discovery, containment and cleanup
of such release. In the event of such a release of hazardous materials,
said person shall immediately notify emergency response agencies of
the occurrence via emergency dispatch services.
2.
In the event of a release of non-hazardous materials, said person
shall notify the administrative officer in person or by phone or facsimile
no later than the next business day. Notifications in person or by
phone shall be confirmed by written notice addressed and mailed to
the administrative officer within three (3) business days of the phone
notice. If the discharge of prohibited materials emanates from a commercial
or industrial establishment, the owner or operator of such establishment
shall also retain an on-site written record of the discharge and the
actions taken to prevent its recurrence. Such records shall be retained
for at least three (3) years.
[R.O. 2007 §31½-20; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
It
shall be the duty of the administrative officer to bring to the attention
of the City Attorney any violation or lack of compliance herewith.
1.
Violations and penalties. Any person, firm or corporation
who fails to comply with or violates any of these regulations shall
be guilty of a misdemeanor and upon conviction thereof shall be fined
not more than five hundred dollars ($500.00) per day of violation
or be confined in the City Jail for not more than one (1) year, or
both.
2.
Inspection. The administrative officer shall be
responsible for determining whether the storm water management plan
is in conformance with requirements specified in storm water management
regulation and whether development is proceeding in accordance with
the approved storm water management plan and permit. The administrative
officer or his/her administrative officer shall make periodic inspection
of the development site. Through such periodic inspections the administrative
officer shall ensure that the storm water management plan is properly
implemented and that the improvements are maintained. After construction
is completed, the engineer shall submit a certification that all the
work has been completed in accordance with the storm water management
plan.
3.
Remedial work. If it is determined through inspection
that development is not proceeding in accordance with the approved
storm water management plan and permit, the City administrative officer
shall immediately issue a written notice to the permittee and surety
of the nature and location of the alleged non-compliance, accompanied
by documentary evidence demonstrating non-compliance and specifying
what remedial work is necessary to bring the project into compliance.
The permittee so notified shall immediately, unless weather conditions
or other factors beyond the control of the permittee prevent immediate
remedial action, commence the recommended remedial action and shall
complete the remedial work within seventy-two (72) hours or within
a reasonable time after receipt of said notice. Upon satisfactory
completion of the remedial work the administrative officer shall issue
a notice of compliance and the development may proceed.
4.
Revocation of permits — stop orders. The administrative officer, after giving three (3) days' written notice, may revoke a permit issued pursuant to these regulations for any project which is found upon inspection to be in violation of the provisions of these regulations and for which the permittee has not agreed to undertake remedial work as provided in Subsection (A)(3). Permits may also be revoked if remedial work is not completed within the time allowed. Upon revocation of a permit the administrative officer shall issue a stop work order. Such stop work order shall be directed to the permittee and he/she shall immediately notify persons owning the land, the developer and those persons or firms actually performing the physical work of clearing, grading and developing the land. The stop work order shall direct the parties involved to cease and desist all or any portion of the work on the development or a portion thereof which is not in compliance, except such remedial work necessary to bring the project into compliance.
B.
Appeals. Any person aggrieved by a decision of the administrative officer may appeal any order, requirement, decision or determination first to the Board of Adjustment and then to a court of competent jurisdiction in accordance with the procedures set forth in Chapter 405 of the City Code of Ordinances entitled "Zoning Regulation", Section 405.330.
[R.O. 2007 §31½-21; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
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 no 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.
B.
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 or persons responsible.
[R.O. 2007 §31½-22; Ord. No.
6659 §2(Exh. A), 10-20-2003]
This Chapter shall not in any way limit or modify the vested
rights of any person to complete any development or improvements 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.
[R.O. 2007 §31½-23; Ord. No.
6659 §2(Exh. A), 10-20-2003]
In the case of conflict 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.
[R.O. 2007 §31½-24; Ord. No.
6659 §2(Exh. A), 10-20-2003]
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 plan drawing(s) 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.
[R.O. 2007 §31½-25; Ord. No.
6659 §2(Exh. A), 10-20-2003]
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 the State
Statutes.
[R.O. 2007 §31½-26; Ord. No.
6659 §2(Exh. A), 10-20-2003]
A.
Separability. If any part of this Chapter is held to be
unconstitutional, it shall be construed to have been the legislative
intent to pass this Chapter without such unconstitutional part, and
the remainder of this Chapter, as to the exclusion of such part, shall
be deemed and held to be valid as if such part had not been included
herein. If this Chapter or any provision hereof is held to be inapplicable
to any persons, group of persons, property, kind of property, circumstances
or set of circumstances, such holding shall not affect the applicability
hereof to any other person, property or circumstances.
B.
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.
[R.O. 2007 §31½-27; Ord. No.
6659 §2(Exh. A), 10-20-2003]
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 of safety of any drainage management structure or use of
land. Nor shall the approval of a storm water management plan and
the issuance of a permit imply that land uses permitted will be free
from damages caused by storm water 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 storm water 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, not
shall compliance relieve an owner, developer and/or permittee from
responsibility under any circumstances where liability would otherwise
exist.
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Modified Retention Hydrograph
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Overland Flow Time
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