[R.O. 2011 §16.16.010; Prior Code §29-50; Ord. No. 6143 §1(part), 1997]
The layout of a development, including the orientation of lots
and structures thereon, shall be designed to provide desirable building
sites logically related to topography, natural features, streets,
parking areas, common land (if any), other structures, and adjacent
land uses. Subdivisions and land development within the City shall
consider surrounding land uses, both in terms of the impact of the
proposed development on the surrounding area, and any existing or
potential impacts of adjacent land uses on the proposed development.
Due regard shall be given to natural features (such as large trees
and watercourses), presence of historic landmarks or districts, the
proximity and density of nearby residential areas, and any other on-
or off-site conditions.
[R.O. 2011 §16.16.020; Prior Code §29-51; Ord. No. 6143 §1(part), 1997]
The subdivision or development shall comply with the standards
contained in this Chapter and any other standards or design criteria
established by the City, utility companies or agencies having jurisdiction.
[R.O. 2011 §16.16.030; Prior Code §29-51.1; Ord. No. 6143 §1(part), 1997]
A.
Every
street, public or private, established after the effective date of
the ordinance codified in this Chapter shall be platted, designed
and built in accordance with the requirements of this Chapter.
B.
Private
drives providing access to parking areas associated with multiple-family
residential developments, or road easements or cross-access easements
associated with non-residential developments shall not be required
to meet the standards for street construction.
C.
Half-width
streets shall be prohibited.
D.
The
street layout shall be appropriate for the type of development proposed
and properly integrated with the street system in the area adjoining
the development.
E.
Residential
streets shall be laid out to discourage through traffic, to permit
efficient drainage and utility systems, and to provide convenient
and safe access to lots.
F.
In conjunction with satisfying the intent of Subsection (E) of this Section, residential streets shall interconnect with surrounding streets where determined to be necessary to permit the convenient movement and dispersion of traffic within the local neighborhood and/or facilitate the access of emergency vehicles.
G.
All
dead-end streets shall be developed with a cul-de-sac turnaround,
with a circular pavement provided in accordance with this Section,
unless the Plan Commission recommends, and the City Council approves,
an equally safe and maneuverable turnaround space. This turnaround
requirement shall not apply to dead-end "stub" streets which do not
exceed two hundred fifty (250) feet in length as measured from the
centerline of the street intersection to the end of the stub street,
provided that the City Council determines that such street provides
a safe means of access for refuse collection, police, fire and emergency
vehicles.
H.
Streets
shall intersect, as nearly as possible, at right angles, and no street
shall intersect with another at less than seventy degrees (70°).
Not more than two (2) streets shall intersect at any one (1) point.
I.
Whenever
possible, proposed street intersections along one (1) side of a street
shall coincide with existing or proposed intersections on the opposite
side of such street. In any event, where a centerline offset ("jog")
occurs at an intersection, the distance between the centerlines of
the intersecting streets shall not be less than one hundred fifty
(150) feet when the intersected street is a residential street, and
not less than two hundred (200) feet when the intersected street is
a collector street or highway.
J.
Street
rights-of-way shall not be placed adjacent to side or rear property
lines of a lot, tract or parcel in an established residential subdivision,
except as is necessary to provide for future connections to adjoining
unsubdivided tracts where recommended by the Plan Commission and approved
by the City Council. A minimum of a twenty-five (25) foot landscaped
buffer, established as common ground, shall be provided between the
street right-of-way and the side or rear property lines of the lots,
tracts or parcels associated with the established residential subdivision.
Intersection roundings shall be exempt from this requirement.
K.
Additional
traffic lanes or other widening, pavement thickness, drainage facilities,
granular base, traffic control devices, and other improvements may
be required to accommodate increased traffic volumes projected to
be generated by the development, unsuitable soil conditions, steep
grades, or other conditions.
[R.O. 2011 §16.16.040; Prior Code §29-51.2; Ord. No. 6143 §1(part), 1997]
A.
All
streets shall comply with the applicable standards contained in the
Design Criteria for the Preparation of Improvement Plans established
and updated from time to time by the St. Louis County Department of
Highways and Traffic, except that the standards established herein
shall be the minimum requirement. The City may require additional
right-of-way and/or improvements as may be required to accommodate
the proposed development and its impact on adjacent streets. The Zoning
Administrator, with the advice of the Director of Public Works and
Parks, may require that the applicant for subdivision plat approval
provide a traffic study to assist in determining what additional improvements
and/or right-of-way may be necessary. Where a development is accessed
from a street or highway under the jurisdiction of the State or County,
any required improvements thereon and intersecting streets or drives
shall be designed and constructed in accordance with the requirements
of the respective agency.
1.
Minor (residential) street dimensional specifications.
a.
Minimum right-of-way. Fifty (50) feet.
b.
Minimum pavement width (measured back-to-back of curbs). Thirty (30) feet.
e.
Street pavement. Concrete or asphalt only.
f.
Curb and gutter. Concrete, vertical or lip (rolled),
with wheelchair accessible curb ramps provided at sidewalk intersections,
designed in accordance with the standards of the Department of Public
Works and Parks or other authority having jurisdiction.
h.
Tree lawns: The minimum width between the back of
curb to the closest edge of sidewalk shall be five (5) feet.
2.
Non-residential and collector street dimensional specifications.
a.
Minimum right-of-way. Sixty (60) feet.
b.
Minimum pavement width (measured back-to-back of curbs). Thirty-eight (38) feet.
c.
Minimum cul-de-sac turnaround.
(1)
Right-of-way radius. Sixty-seven (67) feet.
(2)
Pavement radius (to back of curb). Fifty-five
(55) feet.
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Exception: The Plan Commission may recommend,
and the City Council may approve, a pavement radius of not less than
forty-two (42) feet and a right-of-way radius of not less than fifty-four
(54) feet where parking or loading areas provide for suitable turnaround
movements.
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e.
Street pavement. Concrete or asphalt only.
f.
Curb and gutter. Concrete, vertical only, with wheelchair-accessible
curb ramps provided at sidewalk intersections, designed in accordance
with the standards of the Department of Public Works and Parks or
other authority having jurisdiction.
h.
Tree lawns: The minimum width between the back of
curb to the closest edge of sidewalk shall be five (5) feet.
3.
Miscellaneous geometric requirements.
a.
All pavement surfaces shall be centered within the right-of-way without
exception.
b.
The minimum height of the street crown shall be determined by using
a cross slope of two percent (2%), or as required by geometric pavement
design approved by the Director of Public Works and Parks.
c.
Intersections shall be designed with grades as level as possible,
notwithstanding provisions for proper drainage. Approaches to intersections
shall not have a grade exceeding three percent (3%) for a distance
of not less than one hundred fifty (150) feet, measured from the centerline
of the intersecting street.
d.
A tree lawn of not less than five (5) feet, between the back of curb
to the closest edge of the sidewalk, shall be provided. Tree lawns
shall be planted with landscaping material such as grass; provided
however, that any trees to be planted therein shall be of a species
approved by the City Urban Forester through the Zoning Administrator.
4.
Street names.
a.
Proposed through streets, which are continuations of, or in general
alignment with, existing streets, shall bear the names of such existing
streets.
b.
Except as required under Subsection (4)(a) of this Section, the name of a proposed street shall not duplicate the name of any existing or platted street within St. Louis County.
c.
All names of the streets proposed by the developer shall be approved
by the St. Louis County Department of Revenue and the United States
Post Office prior to submitting the final plat to the City for review.
[R.O. 2011 §16.16.050; Prior Code §29-51.3; Ord. No. 6143 §1(part), 1997]
A.
Sidewalk Requirements.
1.
Except as provided for herein, sidewalks shall be provided along
both sides of any street, including around any cul-de-sac.
2.
Sidewalks or pedestrian ways may be required elsewhere within a development
to provide access to parks, schools, public transportation facilities,
common land, or similar areas, when the Plan Commission finds that
such sidewalks or pedestrian ways are necessary to promote public
safely.
3.
Sidewalks or pedestrian ways shall be constructed in accordance with
the specifications established by the Director of Public Works and
Parks. The minimum requirements for sidewalks shall be as follows:
a.
Residential sidewalks or pedestrian ways shall be concrete having
a minimum thickness of four (4) inches and increased to six (6) inches
at driveway entrances. The minimum width of sidewalks in residential
developments shall be four (4) feet, except that wider widths may
be required by the City Council upon recommendation from the Plan
Commission.
b.
Non-residential sidewalks shall be concrete having a minimum thickness
of four (4) inches and increased to seven (7) inches at driveway entrances.
The minimum width of sidewalks in non-residential developments shall
be four (4) feet, except that wider widths may be required by the
City Council upon recommendation from the Plan Commission.
c.
Sidewalks and pedestrian ways shall be disability accessible.
d.
Where sidewalks do not presently exist along the portion of Olive
Boulevard that is a State highway, sidewalks shall be provided. However,
if the Missouri Department of Transportation prohibits such sidewalks
within the State right-of-way, then the sidewalks shall be placed
in a public easement outside of the right-of-way.
4.
Pedestrian ways, as distinguished from sidewalks along streets, may
be constructed with other suitable materials. Use of such materials
shall be subject to the approval of the Director of Public Works and
Parks when the developer can demonstrate that:
B.
Sidewalk Variance Procedure. A developer may request a waiver from the requirement for sidewalks along a street in accordance with the variance procedure outlined in Section 405.110. The Zoning Administrator, with the advice of the Director of Public Works and Parks, shall provide a report to the Plan Commission concerning the conditions within the street right-of-way involved with the request. The Plan Commission may recommend and the City Council may approve a waiver in the following cases:
1.
Where sidewalks are not deemed necessary for the public safety or
where topographical or other conditions make their installation and
use impractical;
2.
Where the applicant has submitted an alternative sidewalk plan that
provides for more direct and safer movement of pedestrian traffic;
or
3.
Where the applicant can demonstrate that justifiable conditions exist
wherein the strict application of requirements contained in this Section
would:
[R.O. 2011 §16.16.060; Prior Code §29-51.4; Ord. No. 6143 §1(part), 1997]
A.
Lots Generally.
1.
Every lot shall have access from a public street, except for non-residential
lots accessed by a roadway easement or cross-access easement approved
by the City Council and recorded on a record or easement plat.
2.
The minimum area of lots shall be in accordance with the regulations of the zoning district in which the lots are located (see Article IV of the Zoning Code).
3.
The side lot lines of lots shall generally be at right angles to
straight street lines, and radial to curved street lines, unless a
deviation from this general standard would provide a better street
and lot plan in the judgment of the Plan Commission.
4.
The minimum lot width, as defined in the Zoning Code, is measured
along the front building setback line. In no case shall the width
of the lot, as measured along the street right-of-way line, be less
than fifty percent (50%) of the minimum lot width.
5.
Through lots should be avoided, except where necessary to provide
separation of the subdivision from major or secondary streets, or
as otherwise required by topography or similar conditions.
6.
Through lots shall have driveway access only from the internal residential
(local) street, unless it is impractical to do so because of topography
or similar conditions.
B.
Corner Lots.
1.
Corner lots shall have adequate width to permit the required building setback lines from both streets (see Article IV of the Zoning Code).
2.
Corner lots, located at the intersection of a collector street and a residential (minor) street, shall have driveway access from the residential (local) street, unless it is impractical to do so because of topography or similar conditions. Driveways shall be located as far from the street intersection as practical and shall not be located within the area described in Article V, Section 400.1410 of the Zoning Code (visibility at intersections).
C.
Flag Lots. Flag lots shall not be permitted.
[R.O. 2011 §16.16.070; Prior Code §29-51.5; Ord. No. 6143 §1(part), 1997]
A.
General Requirements.
1.
In any case in which a developer installs or causes the installation
of water, sanitary sewer, storm sewer, electrical power, telephone,
cable television, or other facilities outside a public street right-of-way,
and intends that such facilities shall be owned, operated, or maintained
by a public utility or any entity other than the developer, the developer
shall transfer to such utility or entity the necessary ownership or
easement rights to enable the utility or entity to operate and maintain
such facilities upon their completion and acceptance by the utility
or entity. Such easements shall be clearly indicated on the final
subdivision plat.
2.
Where possible, easements should be located along rear and side lot
lines. Such easements shall not be less than ten (10) feet in width,
which may be divided evenly between abutting properties.
B.
Storm Drainage Easements.
1.
Storm drainage easements may be required for the proper drainage
within and through a development. Wherever a subdivision is traversed
by a watercourse, drainage channel or stream, there shall be provided
a drainage easement which shall be for the purpose of widening, straightening,
improving and maintaining such drainage way. The width of the drainage
easement shall be as necessary for the access and maintenance of the
drainage way or as required by MSD.
2.
Access easements shall be established as necessary to provide an
unobstructed route to the storm drainage easement area for maintenance
equipment. Separately designated access easements shall not be less
than twenty (20) feet or as specified by MSD.
[R.O. 2011 §16.16.080; Prior Code §29-51.6; Ord. No. 6143 §1(part), 1997]
A.
Underground Wiring Required. All electric, lighting, telephone,
and cable television distribution lines shall be installed underground,
except those feeder lines necessary to serve the development and in
locations approved by the Zoning Administrator. Switching enclosures,
pad-mounted transformers, and service pedestals may also be installed
above ground in locations approved by the Zoning Administrator. The
City Council may approve, upon recommendations from the Plan Commission,
above ground installations in whole or in part for developments, only
when a request is submitted by the developer with documentation that
supports the impracticability of installing such utility lines underground.
B.
Water Facilities.
1.
The developer shall secure water service to each lot within the development
for the purpose of providing sufficient potable water supply and fire
protection.
2.
The developer shall arrange for installation of water mains. Fire
hydrants shall be located and installed in accordance with specifications
established by the Fire Chief.
C.
Sanitary And Storm Sewers.
1.
Adequate sanitary sewer collection lines shall be provided and accessible
to each lot. All sanitary sewers, sanitary sewer connections, manholes,
and other sanitary sewer installations serving the development shall
comply with MSD design standards and design standards established
by the Director of Public Works and Parks. In instances where there
are differences between MSD standards and those established by the
Director of Public Works and Parks, the most restrictive standard
shall apply. The developer shall be responsible for installing all
required building service connections.
2.
Every development shall be designed to control storm water runoff.
All storm sewers, storm sewer connections, detention/retention facilities,
and other storm drainage improvements shall comply with MSD design
standards and design standards established by the Director of Public
Works and Parks. In instances where there are differences between
MSD standards and those established by the Director of Public Works
and Parks, the most restrictive standard shall apply.
3.
Within the "LC", "GC", "RC", "IC", "PD-C" and "PD-IC" zoning districts,
all storm drainage detention facilities shall be installed underground.
4.
In residential developments, drainage/retention facilities and land area required to provide access to such facilities shall be located within common ground. Drainage detention facilities or other storm drainage facilities that will not be maintained by MSD shall be conveyed to the trustees of the subdivision for maintenance purposes in accordance with Sections 405.360 and 405.370.
5.
In single-lot developments, drainage detention facilities or other
storm drainage facilities that will not be maintained by MSD shall
be maintained by the property owner.
6.
Drainage discharge. All drainage provisions shall
be of such design to carry surface waters to the nearest practical
storm drain or natural watercourse as approved by the Director of
Public Works and Parks. The finished grade of sites, one (1) acre
or greater in area, from which all or a portion will drain into a
natural or improved drainage way, shall be so designed so that storm
water runoff is intercepted by diversion swales or area inlets, and
lowered to a stable outlet constructed of concrete, rip-rap, pipe,
or other techniques required by MSD or as specified by the Director
of Public Works and Parks. The rate of discharge of surface water
runoff shall be in accordance with the requirements of MSD, except
that the Director of Public Works and Parks may require a more restrictive
discharge rate in areas where flash flooding, bank erosion, or other
chronic storm water drainage problems exist.
D.
Other Utilities. The design and installation of other utilities
(e.g., electric distribution, gas mains and services, telephone and
cable television) shall be provided at a service level necessary for
the development and in accordance with the specifications, approval,
and inspection requirements of the applicable utility company.
E.
All Underground Utilities. All existing trees that are to
be preserved shall be protected from damage by excavation activities.
Roots of such trees shall not be cut without express approval of the
City Forester.
A.
General Requirements. All public streets shall be sufficiently
illuminated to promote the security of property and the safety of
persons using such streets or other common areas or facilities. Effort
shall be made to provide uniform surface illumination so as to avoid
dark spots or areas having significantly less light than the average
illumination. Lighting levels for roadway street lighting are aimed
at promoting efficient traffic movement, assisting in areas of high
pedestrian nighttime activity, reducing light pollution, and supporting
energy conservation.
B.
Street Lighting Standards.
1.
Street light fixture standards. Street light fixtures
shall be of Post Top style (consisting of a 12 to 16 foot pole with
a decorative fixture at the top) for residential developments or Cobra
style (consisting of a 25 to 30 foot pole with an arm extended over
the roadway with an attached light fixture) for non-residential developments
unless coordinating with like fixtures in the area is necessary. These
fixtures shall be one of the typical Ameren street light standards,
except for areas where the City has supplementary lighting specifications.
All light standards and fixtures shall be subject to the approval
of the Director of Public Works and Parks.
2.
Illumination standards.
a.
Residential. Street light fixtures shall have a
maximum 9,500 initial lumen output (or photometric equivalent) with
a preferred minimum output of 120 lumens per watt. The maintained
average level of illuminance shall be 0.4 foot-candles on the roadway.
In addition, new fixtures should have a preferred scotopic/photopic
ratio of at least 1.3 and have a minimum lamp life of 20,000 hours.
b.
Non-residential. Fixtures at intersections should
have should have a minimum *25,500 initial lumen output (or photometric
equivalent) with a preferred minimum output of 120 lumens per watt.
The minimum maintained average level of illuminance shall be 1.5 foot-candles
at intersections. In addition, new fixtures should have a preferred
scotopic/photopic ratio of at least 1.3 and have a minimum lamp life
of 20,000 hours. Non-intersection fixtures should have a minimum of
*9,500 lumens output and a 0.8 foot- candle minimum maintained average.
3.
Height requirements. The lighting source shall not
be less than twelve (12) feet or greater than thirty (30) feet above
grade, except as may be required for major streets and highways.
4.
Location requirements.
a.
General. Street lights shall be provided at each
intersection of a street within the subdivision, on street frontage
between intersections, at each intersection of a street with a sidewalk
or pedestrian way, and at each cul-de-sac turnaround. Light standards
shall not be located within three (3) feet of the back of the street
curb. Where sidewalks are required, street light standards shall be
located between the sidewalk and the street curb. Variations to the
latter two (2) requirements may be approved by the Director of Public
Works and Parks so long as proper illumination is achieved without
impairing pedestrian and vehicular traffic safety.
b.
Residential subdivisions. Residential streets shall
have street lights installed at a maximum spacing of three hundred
(300) feet.
c.
Non-residential subdivisions. Non-residential streets
shall have street lights installed at a maximum spacing of two hundred
(200) feet.
5.
Installation expense, maintenance and operation. Street lights shall be installed at the expense of the developer.
Upon acceptance of streets for maintenance by the City, the City will
assume financial responsibility for the ensuing electric charges for
street lights located in City street rights-of-way. All other lighting
expenses shall be the responsibility of the property owner or the
owners in common. In the latter case, the trust indenture, or similar
instrument, as required in this Title, shall provide for the assessment
and collection of monies necessary for the operation of the common
lighting system.
[R.O. 2011 §16.16.100; Prior Code §29-51.8; Ord. No. 6143 §1(part), 1997]
A.
The
minimum standards of grading and erosion control shall be as follows;
however, more stringent standards may be required by the Director
of Public Works and Parks based on site conditions:
1.
Site grading.
a.
Phasing. Site grading shall be phased, as necessary, so that each graded area of the construction site has long-term erosion control measures in place within six (6) months of initiating grading for each graded area. The grading and erosion control plans, required in Section 405.280, shall indicate the proposed grading phasing, either by graphic delineation of phasing on the plan or on a key map of the site. The grading and erosion control plans shall provide cut and fill quantities and delineate borrow and stockpile areas.
b.
Site grading and storm drainage control. Lots shall
be graded so as to provide positive drainage away from all buildings
to be built thereon. Individual lot drainage shall be coordinated
with the general storm drainage pattern for the area. Site grading
shall be designed so as to substantially prevent storm water drainage
from one lot to another.
c.
Maximum finished grade slopes. No cut or fill shall be made which creates an exposed embankment face steeper in slope than three (3) horizontal units to one (1) vertical unit. The embanked end of the fill shall be uniformly compacted and stable for the proposed conditions as provided in Subsection (1)(e) of this Section. If a steeper slope is proposed, its stability shall be certified by a registered soils engineer.
d.
Retaining walls. Retaining walls shall be required
wherever necessary to prevent the surface of any excavation or fill
from exceeding at any point the maximum allowable slopes as set forth
herein and for the preservation of existing significant trees. Retaining
walls shall be constructed with reinforced concrete or interlocking
masonry units.
e.
Compaction. All fills shall be compacted to a minimum
of ninety percent (90%) compaction as determined by Modified Proctor,
ASTM D-1557, unless a lesser percent is approved by the Director of
Public Works and Parks. Compaction of greater than ninety percent
(90%) may be required where special conditions dictate (e.g., large
structures or dams). Compaction of fills for buildings or structures
shall be certified by a registered engineer. The requirements of the
Director of Public Works and Parks for the compaction of fills shall
include, but shall not be limited to, the following:
(1)
Areas to be graded by cutting or filling shall be rough graded
to within two-tenths (.2) of a foot of accepted elevation after allowance
has been made for thickness of topsoil, paved areas and other installations.
(2)
The natural ground surface shall be prepared by removing topsoil
and vegetation and by compacting the fill upon a series of terraces.
Hillside or slope fills shall require plowing or scarification of
original ground.
(3)
If fill material moisture content is below the requirement for
compacting to maximum practical density, water in proper amount shall
be added. If moisture content is too great, fill material shall be
aerated by blading or other satisfactory methods to reduce moisture
content.
(4)
Frozen materials, soft, mucky, friable or easily compressible
materials shall not be incorporated in fills intended to support buildings,
structures, sewers or conduits, or in the embanked ends of fills.
After heavy rain, interrupted work shall not be resumed until moisture
content is satisfactory. Fill material shall not be placed, spread
or rolled while the ground is frozen or thawing.
(5)
The maximum thickness of layers of the fill to be compacted
shall not exceed eight (8) inches.
(6)
Compaction shall be by tamping, sheep's foot rollers, multiple
wheel pneumatic or other type rollers. Rolling shall be continuous
until the desired maximum density is obtained.
(8)
Topsoil disturbed by grading and building operations, if stripped
and piled for storage, shall be stored only in an amount necessary
to complete finished grading.
f.
Protection of streets, property. No excavation shall
be made so close to the property line to endanger any adjoining public
or private street without supporting and protecting such public or
private street or property from settling, cracking or other damage.
g.
Location of fill. No fill shall be made so as to
cause or to allow the same to be deposited upon or over any public
street, walk, place or way; nor so close to the top of a bank of a
channel as to create the possibility of bank failure and sliding.
h.
Fill materials. Materials for fills shall consist
of material obtained from excavation of banks, borrow pits or other
sources approved by the Director of Public Works and Parks. Materials
shall be free of vegetable matter and deleterious material and shall
not contain large rocks in excess of six (6) inches in diameter.
i.
Removal of timber, rubbish, etc. Timber, logs, trees,
brush, vegetable matter and rubbish of any description shall be removed
in graded areas and disposed of so as to leave the disturbed area
with a neat and finished appearance. Tree stumps, masonry and other
obstruction shall be removed to the following depths:
(1)
Paved areas. Two (2) feet below subgrade.
(2)
Lawn areas. Two (2) feet below finished grade.
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Solid rock, shale or similar materials shall be removed to a
depth of fifteen (15) inches below subgrade for paved area and two
(2) feet below finish grade for lawn area except where it is impractical
because of rock out-cropping.
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j.
Protection of trees. Trees which are designated
to remain shall be enclosed with a five (5) foot high temporary construction
fence located at the drip line of the tree. No grading activity or
storage shall take place within the enclosure.
k.
Timing of grading operations. Grading shall be accomplished
between the hours of 7:00 A.M. and 7:00 P.M., Monday through Saturday,
unless in the case of emergency or an extension of hours is specifically
granted by the City Council.
2.
Excavations and fill under pavements (on site).
a.
All open excavations for installation of any underground utilities
(except the gas utility), communications lines, and similar installations
made under existing pavement or areas proposed to be paved shall be
backfilled with granular backfill material, approved by the Director
of Public Works and Parks, thoroughly compacted in such a manner as
to inhibit any settlement of the backfill material or finished pavement.
b.
The exemption of the gas utility from the granular backfill requirements
of this Section does not exempt that utility from thorough compaction
of its backfill so as to avoid pavement settlement.
3.
Erosion/siltation control. Every subdivision or land development shall make adequate provisions to minimize and control both short-term and long-term erosion and siltation in accordance with the requirements of this Section and any storm drainage control requirements of MSD. The Director of Public Works and Parks shall establish specific standards to ensure the compliance with the intent of these erosion and siltation control requirements. The Director of Public Works and Parks may require modifications or additions to the erosion control plans should the proposed measures not adequately control erosion and siltation. If construction activities disturb land or entail the grading of an area that is one (1) acre or greater, or if that construction activity is part of a lager common plan of development or sale that would disturb one (1) acre or greater, a land disturbance permit shall be obtained from the Missouri Department of Natural Resources (see Section 405.140(C)).
[Ord. No. 7058, 10-23-2017]
a.
Temporary erosion/siltation control measures. Temporary
erosion and sediment control measures are intended to retain siltation
within the development site, particularly if construction is not completed
within a single construction season. Temporary erosion and siltation
control measures shall be maintained until long-term erosion/siltation
control measures are fully established, including such time that vegetative
cover is established at a sufficient density to provide erosion control
on the site. Temporary erosion/siltation control measures shall include,
but are not necessarily limited to, the following:
(1)
Graded areas shall be stabilized immediately upon grading and
maintained to prevent or minimize erosion until permanent stabilization
measures are in place. Permissible erosion control techniques include
contour furrowing or other surface roughening techniques, mulching,
sodding, or other techniques approved by the Director of Public Works
and Parks.
(2)
Sedimentation shall be retained on the site by filtering runoff.
Where grading exceeds twenty thousand (20,000) square feet in area,
the erosion/siltation control plans shall provide for sediment or
debris basins, silt traps or filters, staked straw bails and/or geotextile
fabric, or other measures to remove sediment from runoff waters as
approved by the Director of Public Works and Parks.
(3)
Slope shall be designed to keep the slope length and gradient
to a minimum to minimize storm water runoff velocities over graded
areas.
(4)
Measures shall be taken to accommodate increased runoff during
grading by utilizing diversion berms, ditches and/or sediment basins
designed in accordance with the standards established by the Director
of Public Works and Parks.
(5)
Land and improvements, adjoining the construction site, shall
be provided protection from any increase in surface water, siltation
deposits, or any other consequences of erosion. Where it is necessary
for the protection of such property, to enter upon such property,
consent must be obtained from the property owner. The developer, at
his/her own expense, shall shore up and protect any and all buildings,
walls, fences or other property that are exposed to any potential
damage as a result of grading the site. The developer shall be responsible
for all damage to public or private property resulting from his/her
failure to properly protect adjoining properties.
(6)
Runoff water from existing developed areas (e.g., parking lots,
paved sites, buildings and similar impervious surfaces) above the
area to be graded shall be intercepted by sufficiently anchored straw
bails and/or geotextile fabric until such time such runoff can be
directed to diversions, detention basins, concrete gutters, underground
outlet systems or other permanent storm drainage control measures.
b.
Long-term erosion/siltation control. The site plan
and erosion control, storm drainage control, and landscape plans shall
be designed to minimize erosion potential upon completion of the development
and thereafter. In support of this requirement, the following design
standards and guidelines shall apply:
(1)
The finished grading shall provide for sediment basins, diversion
berms, permanent bank stabilization, or other erosion control techniques
approved by the Director of Public Works and Parks, whenever necessary
to avoid damage to adjoining properties, street, sidewalks, storm
drainage ways and storm sewers.
(2)
Landscaping shall be provided in the form of seeded or sodded
grass, ground cover, low walls, earth berms, trees and shrubbery to
enhance the function and appearance of erosion control grading and
facilities.
(3)
When grading operations are completed or when suspended for
more than thirty (30) days, permanent grass must be established at
sufficient density to provide erosion control on the site. Between
permanent grass seeding planting periods (March first (1st) to June
first (1st) and August first (1st) to October first (1st)), temporary
cover shall be provided according to the requirements of the Director
of Public Works and Parks.
(4)
All finished grades (areas not to be disturbed by future improvements)
in excess of twenty percent (20%) slopes (5:1) shall be mulched and
tacked at the rate of one hundred (100) pounds per one thousand (1,000)
square feet when seeded.
(5)
Provisions shall be made to accommodate the increased runoff
caused by changed soil and surface conditions after finished grading.
Unvegetated open channels shall be designed so that gradients result
in velocities of two (2) fps (feet per second) or less. Open channels
with velocities greater than two (2) fps and less than five (5) fps
shall be established with permanent vegetation or by use of commercial
erosion blankets, rip-rap rock lining, concrete, or other suitable
materials as approved by the Director of Public Works and Parks. Detention
basins, diversion berms, or other appropriate structures approved
by the Director shall be constructed to prevent velocities above five
(5) fps.
(6)
Development along natural watercourses shall have residential lot lines, commercial or industrial improvements, parking areas or driveways set back a minimum of fifteen (15) feet from the top of the existing stream bank. The watercourse shall be maintained by the subdivision trustees, in the case of a subdivision (see Sections 405.360 and 405.370), or by the property owner, in the case of an unsubdivided development. Permanent vegetation shall be left intact where practical. These requirements may be waived or modified in cases where stream bank erosion measures and/or improved channel realignments ensure permanent erosion control. Such waiver shall be at the discretion of the Director of Public Works and Parks.
(7)
All permanent erosion control measures for any lot shall be
fully established before an occupancy permit can be issued, except
that a temporary occupancy permit may be issued in cases of undue
hardship because of unfavorable ground conditions. In the latter case,
temporary erosion control measures shall remain in place until such
time as approved by the Director of Public Works and Parks.
4.
Stormwater Consideration In Site Design.
[Ord. No. 7060, 11-13-2017[1]]
a.
Applicability. The standards referenced and adopted in this Section
shall apply to site design for any project which includes alteration
of site drainage or floodplain areas, connection to storm sewer systems
or open storm water channels, and all land disturbance projects encompassing
more than one (1) acre.
b.
MSD Approval Required. All private and public projects to which this
Article is applicable must be reviewed and approved for storm water
issues by the Metropolitan St. Louis Sewer District in accord with
rules, regulations, standards, and procedures of that body prior to
the issuance of any permits for land disturbance or construction.
c.
Submittal Requirements. Applicants for any development, redevelopment,
land disturbance, construction or other undertaking to which this
Article is applicable shall be required to provide any and all information
necessary to enable the Metropolitan St. Louis Sewer District ("MSD"),
the City and City plan review personnel to assess and apply the principles
promulgated by MSD known as "Site Design Guidance — Tools for
Incorporating Post-Construction Stormwater Quality Protection Into
Concept Plans and Land Disturbance Permitting," and "Landscape Guide
for Best Management Practice Design," as revised from time to time.
[1]
Editor's Note: Ord. No. 7060 also changed the title of this
Section from "Site Grading and Erosion Control" to "Site Grading,
Erosion Control, And Stormwater Consideration In Site Design."
[R.O. 2011 §16.16.110; Prior Code §29-51.9; Ord. No. 6143 §1(part), 1997]
Whenever areas designated and platted as common land contain
facilities for retention basins or recreational uses, and for which
periodic maintenance requires the use of heavy equipment, access to
the common land shall be of sufficient width and reasonably graded
to permit access of such maintenance equipment.
[R.O. 2011 §16.16.120; Prior Code §29-51.10; Ord. No. 6143 §1(part), 1997]
A.
Exceptional Development Constraints. Where there is a question
as to the suitability of a proposed subdivision of land, or portion
thereof for its intended use, due to factors such as steep slopes,
rock, soil conditions, high water table, flood conditions or other
adverse natural physical conditions, the Director of Public Works
and Parks may require test borings or other engineering investigations
to determine the severity of such conditions. The Director may withhold
approval of improvement plans until engineering or other relevant
studies are conducted by the applicant and are presented to the Director,
which establish that the methods proposed to alleviate any such conditions
are adequate to avoid any danger to public health, safety, welfare,
or proposed improvements or structures. Conditions may be imposed
on any applicable permit to ensure that the necessary measures are
taken to solve the problems created by unsuitable land conditions.
B.
Construction Testing. The Director of Public Works and Parks
may require that the developer take concrete cylinder or core samples
and have laboratory tests conducted on same, and present same to the
Director, for street and sidewalk pavements to ensure compliance with
design and construction requirements.
[R.O. 2011 §16.16.130; Prior Code §29-51.11; Ord. No. 6143 §1(part), 1997]
A.
Survey Monuments. Survey monuments shall be placed at all
subdivision boundary corners, at all street corners, and at angle
points and points of tangency of curves on one (1) side of each street.
Said monuments shall be constructed in accordance with the Standards
of Missouri Board for Architects, Professional Engineers and Land
Surveyors and Department of Natural Resources.
B.
Benchmark. A permanent benchmark shall be accessibly placed,
the elevation of which shall be based on U.S.G.S. datum, and accurately
noted on the final plat.
