[R.O. 2008 §560.010; Ord. No. 5430 §1, 6-25-1996]
A. The provisions of Chapter
560 shall constitute and be known as the "Storm Water Management Ordinance" for the City of Maryville, Missouri, hereby called the "Municipality".
B. The
purpose of this Chapter is to protect, maintain, and enhance the public
health, safety and general welfare by establishing the minimum requirements
and procedures to control the adverse effects of increased stormwater
runoff associated with both future land development and existing developed
land within the municipality. Proper management of stormwater runoff
will minimize damage to public and private property, ensure a functional
drainage system, reduce the effects of development on land and stream
channel erosion, assist in the attainment and maintenance of water
quality standards, enhance the local environment associated with the
drainage system, reduce local flooding, maintain as nearly as possible
the pre-developed runoff characteristics of the area and facilitate
economic development while mitigating associated flooding and drainage
impacts.
C. The
application of this Chapter and the provisions expressed herein shall
be the minimum stormwater management requirements and shall not be
deemed a limitation or repeal of any other powers granted by State
Statute. In addition, if site characteristics indicate that complying
with these minimum requirements will not provide adequate designs
or protection for local property or residents, it is the designer's
responsibility to exceed the minimum requirements as necessary. The
Director of Public Works shall be responsible for the coordination
and enforcement of the provisions of this Chapter.
[R.O. 2008 §560.020; Ord. No. 5430 §1, 6-25-1996]
For the purpose of this Chapter, the following terms, phrases
and words and their derivatives shall have the meaning given herein:
2-YEAR FREQUENCY STORM
A storm that is capable of producing rainfall expected to
be equaled or exceeded on the average of once in two (2) years. It
may also be expressed as an exceedance probability with a fifty percent
(50%) chance of being equaled or exceeded in any given year.
10-YEAR FREQUENCY STORM
A storm that is capable of producing rainfall expected to
be equaled or exceeded on the average of once in ten (10) years. It
may also be expressed as an exceedance probability with a ten percent
(10%) chance of being equaled or exceeded in any given year.
25-YEAR FREQUENCY STORM
A storm that is capable of producing rainfall expected to
be equaled or exceeded on the average of once in twenty-five (25)
years. It may also be expressed as an exceedance probability with
a four percent (4%) chance of being equaled or exceeded in any given
year.
100-YEAR FREQUENCY STORM
A storm that is capable of producing rainfall expected to
be equaled or exceeded on the average of one (1) in one hundred (100)
years. It also may be expressed as an exceedance probability with
a one percent (1%) chance of being equaled or exceeded in any given
year.
AS-BUILT PLAN
A set of engineering or site drawings that delineate the
specific permitted stormwater management facility as actually constructed.
BEST MANAGEMENT PRACTICES
A wide range of management procedures, schedules of activities,
prohibitions on practices and other management practices which have
been demonstrated to effectively control the quality and/or quantity
of stormwater runoff and which are compatible with the planned land
use.
CITY MANAGER
The official responsible for the administration of the City
or his/her duly authorized representative.
DESIGN REPORT
The report that accompanies the stormwater management plan
and includes data used for engineering analysis, results of all analysis,
design and analysis calculations (including results obtained from
computer programs), and other engineering data that would assist the
municipality in evaluating proposed stormwater management facilities.
DESIGNER
A professional engineer, architect or land surveyor, licensed
in the State of Missouri who prepares plans and studies required by
this Chapter.
DETENTION STRUCTURE
A permanent stormwater management structure whose primary
purpose is to temporarily store stormwater runoff and release the
stored runoff at control rates.
DEVELOP LAND
To change the runoff characteristics of a parcel of land
in conjunction with residential, commercial, industrial or institutional
construction or alteration.
DEVELOPMENT
Should generally mean any of the following actions undertaken
by a public or private individual or entity:
1.
The division of a lot, tract or parcel of land into two (2)
or more lots, plots, sites, tracts, parcels or other divisions by
plat or deed, or
2.
Any land change, including, without limitation, clearing, tree
removal, grubbing, stripping, dredging, grading, excavating, transporting
and filling of land.
DIRECTOR, PUBLIC WORKS
The individual designated by the City Manager to direct the
operations of the Public Works Department.
EASEMENT
A grant or reservation by the owner of land for the use of
such land by others for a specific purpose or purposes, and which
must be included in the conveyance of land affected by such easement.
EROSION
The wearing away of land surface by the action of wind, water,
gravity, ice or any combination of those forces.
EROSION AND SEDIMENT CONTROL
The control of solid material, both mineral and organic during
a land disturbing activity to prevent its transport out of the disturbed
area by means of air, water, gravity or ice.
EXISTING LAND USE CONDITIONS
The land use conditions existing at the time of the most
recent official aerial photograph available from the municipality.
GRADING
Excavating, filling, (including hydraulic fill) or stockpiling
of earth material, or any combination thereof, including the land
in its excavated or filled conditions.
IMPERVIOUS
The condition of being impenetrable by water.
INFILTRATION
The passage or movement of water through the soil profile.
LAND DISTURBING ACTIVITY
Any use of land by any person that results in a change in
the natural cover or topography that may cause erosion and contribute
to sediment and alter the quality and/or quantity of stormwater runoff.
LOT SPLIT
The division of a platted lot into two (2) parcels not involving
the dedication or vacation of a street or alley.
MAINTENANCE
Any action necessary to preserve stormwater management facilities in proper working condition, in order to serve the intended purposes set forth in Article
I of this Chapter and to prevent structural failure of such facilities. Maintenance shall not include actions taken solely for the purpose of enhancing the aesthetic aspects associated with stormwater management facilities.
NATURAL WATERWAYS
Waterways that are part of the natural topography. They usually
maintain a continuous or seasonal flow during the year and are characterized
as being irregular in cross-section with a meandering course. Construction
channels such as drainage ditches shall not be considered natural
waterways.
NON-ERODIBLE
A material, e.g., natural rock, riprap, concrete, plastic,
etc., that will not experience surface wear due to natural forces
of wind, water, ice, gravity or a combination of those forces.
OFFICIAL MAP
The Zoning Map adopted by the City Council showing the zoning
districts, streets, highways and parts theretofore laid out, adopted
and established by law and any amendments thereto adopted by the City
Council or additions thereto resulting from the approval of subdivision
plats and the subsequent filling of such approved plats.
PERSON RESPONSIBLE FOR THE LAND DISTURBING ACTIVITY
1.
The person who has or represents those having financial or operational
control over the land disturbing activity; and/or
2.
The landowner or person in possession or control of the land
who directly or indirectly allowed the land disturbing activity or
has benefitted from it or who has failed to comply with any provision
of this Chapter.
POST DEVELOPMENT CONDITIONS
The conditions which exist following the completion of the
land disturbing activity in terms of topography, vegetation, land
use and rate, volume or direction of stormwater runoff.
PRE-DEVELOPMENT CONDITIONS
Those land use conditions that existed prior to the initiation
of the land disturbing activity in terms of topography, vegetation,
land use and rate, volume or direction of stormwater runoff.
PRELIMINARY PLAT
The preliminary plat of residential or commercial subdivisions
submitted pursuant to the municipality's subdivision regulations.
PUBLIC WORKS DEPARTMENT
The Department of Public Works established by the Council
of the City of Maryville, Missouri.
RECORD SURVEY
A final field survey which locates the visible surface features
of a constructed stormwater facility on the ground, but without locating
non-visible or sub-surface features such as the actual route and elevation
of buried pipe.
REGIONAL STORM WATER MANAGEMENT
The design and construction of a facility necessary to control
stormwater runoff within or outside a development and for one (1)
or more developments.
RESPONSIBLE PERSONNEL
Any foreman, superintendent, or similar individual who is
the on-site person in charge of land disturbing activities.
RETENTION STRUCTURE
A permanent structure whose primary purpose is to permanently
store a given volume of stormwater runoff. Release of the given volume
is by infiltration and/or evaporation.
SEDIMENT
Solid particulate matter, both mineral and organic, that
has been or is being transported by water, air, ice or gravity from
its site of origin.
STABILIZATION
The installation of vegetative or structural measures to
establish a soil cover to reduce soil erosion by stormwater runoff,
wind, ice and gravity.
STAGE WORK or STAGE CONSTRUCTION
A plan for the staged construction of stormwater facilities
where portions of the facilities will be constructed as different
stages of the proposed development are started or completed.
STORM WATER CONCEPT PLAN
The overall proposal for a storm drainage system, including
stormwater management structures, and supporting documentation as
specified in the Storm Water Management Design Guide, for each proposed
private or public development to the extent permitted by law. Also
included are the supporting engineering calculations and results of
any computer analysis, if necessary.
STORM WATER MANAGEMENT DESIGN GUIDE
The manual of design, performance, and review criteria for
stormwater management practices, prepared under the direction of the
municipality or contacted professional. Copies of this manual can
be obtained from the municipality.
STORM WATER MANAGEMENT FACILITIES
Those structures and facilities that are designed for the
collection, conveyance, storage, treatment and disposal of stormwater
runoff into and through the drainage system.
STORM WATER MANAGEMENT PLAN
The set of drawings and other documents that comprise all
of the information and specifications for the drainage systems, structure,
concepts and techniques that will be used to control stormwater as
required by this Chapter and the Storm Water Management Design Guide.
Also included are the supporting engineering calculations and results
of any computer analysis.
STORM WATER RUNOFF
The direct response of a watershed to precipitation and includes
the surface and subsurface runoff that enters a ditch, stream, storm
drain or other concentrated flow during and following the precipitation.
SUBDIVISION, MAJOR
Except for "lot split" as defined, shall
mean the division of a tract of land three (3) or more lots, tracts,
sites, parcels or areas any one of which is less than three (3) acres
in area and/or the division of a tract of land into any number of
lots, tracts, sites, parcels or areas of any size which includes improvements,
new streets, easements, right-of-way, right of ingress and egress
or provisions for a public area or public facility.
SUBDIVISION, MINOR
The division of land into lots, tracts, sites, parcels or
areas for development purposes either of which is three (3) acres
or less in area and each having a frontage of not more than two hundred
(200) feet on an existing City, State or Federal highway or road dedicated
or deeded to the public provided that the proposed subdivision of
land:
1.
Does not include any new streets, easements, right-of-way, rights
of ingress or egress but shall include an approved sewer and water
system.
2.
Does not include a provision for a public area or public facility.
3.
Conforms to the minimum lot area and other requirements contained
in the Zoning Code.
4.
Conveys the right-of-way necessary for road widening and maintenance
of City roads where the granting of such right-of-way can be given
without undue hardship.
SWALE
A structure measure with a lining of grass, riprap or other
materials which can function as a detention structure and convey stormwater
runoff without causing erosion.
VARIANCE
The modification by the City Council of the minimum stormwater
management requirements for specific circumstances where the strict
adherence of the requirements would result in unnecessary hardship
and not fulfill the intent of this Chapter.
WAIVER
The relinquishment from stormwater management requirements
by the City Council for a specific land disturbing activity on a case-by-case
review basis.
WATER QUALITY
Those characteristics of stormwater runoff that relate to
the rate and volume of the stormwater runoff to downstream areas resulting
from land disturbing activities.
WATER QUANTITY
Those characteristics of stormwater runoff from a land disturbing
activity that relates to the physical, chemical, biological, or radiological
integrity of water.
WATERSHED
The drainage area contributing stormwater runoff to a single
point.
[R.O. 2008 §560.030; Ord. No. 5430 §1, 6-25-1996]
No person shall develop any land without having provided for appropriate stormwater management measures that control or manage runoff, in compliance with this Chapter, unless exempted in Article
I, Section
560.040.
[R.O. 2008 §560.040; Ord. No. 5430 §1, 6-25-1996]
A. The
following development activities are exempt from the provisions of
this Chapter and the requirements of providing stormwater management
measures:
1. Land disturbing activities on agricultural land for production of
plants and animals useful to man.
2. Land disturbing activities undertaken on forest land for the production
and harvesting of timber and timber products.
3. Construction or improvement resulting in less than a fifty percent
(50%) increase in square footage of single-family residences or their
accessory buildings.
[R.O. 2008 §560.050; Ord. No. 5430 §1, 6-25-1996]
To assist in the design and evaluation of stormwater management
facilities in the municipality, a Storm Water Management Design Guide
has been developed. Example design procedures and criteria are presented
for conducting hydrologic and hydraulic evaluations. Although the
intention of the guide is to establish uniform design practices, it
neither replaces the need for engineering judgment nor precludes the
use of information not presented. Other accepted engineering procedures
may be used to conduct hydrologic and hydraulic studies if approved
by the municipality.