[Ord. No. 2010-1621 §1, 4-20-2010]
A. Each
owner subject to this Chapter shall submit to the City for review
and approval a stormwater management concept plan as provided herein:
1. Stormwater management concept plan. All preliminary
plans of subdivision and site plans shall provide a stormwater management
concept plan describing, in general, how stormwater runoff through
and from the development will be treated and conveyed. All other land
disturbance projects subject to this Chapter shall submit a stormwater
management concept plan prior to preparation of the stormwater management
design plan.
Exception: The City may waive the requirement
of a concept plan if it is determined by the City that the disturbance
activity is minor in nature and a preliminary review is not necessary.
2. Application requirements. The stormwater management concept plan submittal shall contain a completed application form provided by the City, and a stormwater management concept plan that satisfies the requirements of this Section, the Stormwater Design Manual, and other requirements of Chapter
506 as applicable.
3. Concept plan prior to design plan. The stormwater
management concept plan must be approved prior to submission of a
stormwater management design plan (as part of the construction or
final site plan) for the entire development, or portions thereof.
4. Meetings with the City. All applicants are encouraged
to hold a pre-submittal consultation meeting with the City to discuss
potential approaches for stormwater design and opportunities to use
design techniques to reduce runoff rates, volumes, and pollutant loads.
In addition, the applicant or his representative shall meet on site
with a designee of the City prior to approval of the stormwater management
concept plan for the purposes of verifying the conditions of the site
and all receiving channels.
B. Maximize Use Of Techniques To Reduce Runoff By Design. The
stormwater management concept plan shall utilize, to the maximum extent
practicable, site planning and design techniques that reduce runoff
rates, volumes, and pollutant loads. Such techniques include, but
are not limited to: minimization and/or disconnection of impervious
surfaces; development design that reduces the rate and volume of runoff;
restoration or enhancement of natural areas such as riparian areas,
wetlands, and forest; and distributed practices that intercept and
treat runoff from developed areas.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Each
owner subject to this Chapter shall submit to the City for review
and approval a stormwater management design plan as provided herein:
1. Stormwater management design plan. A stormwater
management design plan containing all appropriate information as specified
in this Chapter shall be submitted to the City in conjunction with
the final subdivision plat, final site plan, construction plan, or
any other land development plan subject to this Chapter.
2. Application requirements. The stormwater management design plan submittal shall contain a completed application form provided by the City, the fee that is required by Section
500.031,
a stormwater management design plan that satisfies the requirements of this Section and the Stormwater Design Manual, a stormwater maintenance plan, and a certification stating compliance with all requirements of the approved plan. Failure of the owner to demonstrate that the project meets these requirements, as determined by the City, shall be reason to deny approval of the plan.
3. Consistency between concept and design plans. A
copy of the approved stormwater management concept plan shall be submitted
with the stormwater management design plan. The City shall check the
design plan for consistency with the concept plan and may require
a revised stormwater management concept plan if changes in the site
development proposal have been made.
4. Stormwater management design plan content. The stormwater
management design plan shall contain maps, charts, graphs, tables,
photographs, narrative descriptions, explanations, citations to supporting
references, a record of all major permit decisions, and other information
as may be necessary for a complete review of the plan, and as specified
in the latest version of the Stormwater Design Manual.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Preliminary Review For Completeness Of Plan. The City shall have a maximum of ten (10) calendar days from the receipt of an application for preliminary review to determine if the application is complete. During this period, the application will be accepted for review, which will begin the thirty (30) day review period, or rejected for incompleteness. If the City determines that the application is not complete, the City shall give written notice to the applicant of that determination and the additional required information necessary to complete the application. Failure of the City to give written notice to the applicant of its determination that the application is incomplete within fifteen (15) days after receipt of an application shall be deemed to constitute plan acceptance for review and the thirty (30) day review period provided for in Subsection
(B) below shall begin on the tenth (10th) day after receipt of the application by the City.
B. Upon
receipt of a complete application, the City shall have thirty (30)
days to review the proposed stormwater management plan. Except as
provided above, the thirty (30) day review period begins on the day
the complete stormwater management design plan is accepted for review
by the City. During the thirty (30) day review period; the City shall
either approve or disapprove the plan and communicate the decision
to the applicant in writing. Approval or denial shall be based on
the plan's compliance with the Frontenac stormwater regulations and
the Stormwater Design Manual, as the same may be amended from time
to time.
C. Modifications Needed For Approval. In cases where modifications
are required to approve the plan, the City shall have an additional
thirty (30) days to review the revised plan from the initial and any
subsequent resubmission dates. If the plan is approved, one (1) copy
bearing certification of such approval shall be returned to the applicant.
If the plan is disapproved, the applicant shall be notified in writing
of the reasons for disapproval and any modifications necessary for
approval.
D. Appeals. The applicant, or any aggrieved party, may appeal
the City's decision of approval or disapproval of a stormwater management
design plan. The appeal shall be made to the Frontenac Board of Adjustment,
in writing, and must be submitted within thirty (30) days after the
City renders its decision to approve or disapprove the plan.
E. Substantive Changes To Plan. No substantive changes shall
be made to an approved plan without review and written approval by
the City. The City may request additional data with a plan amendment
as may be necessary for a complete review of the plan and to ensure
that changes to the plan will comply with the requirements of this
Chapter.
F. Expiration Of Plan Approval. The stormwater management design
plan's approval expires in one (1) year from the date of approval
unless a final plat is recorded or unless work has actually begun
on the site. The recordation of a final plat for a section of a subdivision
(or initiation of construction in a section) does not vest the approval
of the stormwater management design plan for the remainder of the
subdivision. If the stormwater management design plan expires, the
applicant shall file with the City for re-approval of the stormwater
management design plan.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Certification By Plan Preparer. The stormwater management
design plan shall be prepared by a Missouri licensed professional
engineer and must be signed and sealed by the professional preparing
the plan, who shall certify that the design of all stormwater BMPs
meets the requirements in this Chapter.
Exception: The City may waive the need for
a design professional if the work is minor in nature and if the City
determines that the work will not affect the stormwater drainage system.
B. Certification By Owner. The owner shall certify that all
land clearing, construction, land development and drainage will be
done according to the approved plan.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Approval Of Other Permits. No grading or building permit
shall be issued for land disturbance without approval of a stormwater
management design plan as required by this Chapter.
B. Coordination With Other Plans. Approval of the stormwater
management design plan shall be coordinated with a City approved erosion
and sediment control and/or construction stormwater plan with regard
to the location, schedule, and/or phasing of temporary and permanent
stormwater management measures. If natural drainage features or other
natural areas are to be preserved, then these areas must be shown
and measures provided for their protection on both the erosion and
sediment control plan and the stormwater management design plan. If
other elements of the stormwater management design plan utilize soils,
vegetation, or other natural features for infiltration or treatment,
then these areas must be shown on the erosion and sediment control
plan and measures shall be provided for their protection during construction.
C. Other Permits Or Approvals. Approvals issued in accordance
with this Chapter do not relieve the applicant of responsibility for
obtaining all other necessary permits and/or approvals from other
Federal, State, and/or local agencies. If requirements vary, the most
restrictive shall prevail. These permits may include, but are not
limited to, construction stormwater discharge permits, applicable
State and Federal permits for stream and wetland impacts, and applicable
dam safety permits. Applicants are required to show proof of compliance
with these regulations before the City will issue a grading, building,
or zoning permit.
D. Stormwater Measures Within Floodplain. Construction of stormwater
measures or facilities within a Federal Emergency Management Agency
(FEMA) designated floodplain shall be avoided to the extent possible.
When this is unavoidable, all stormwater BMP construction shall be
in compliance with all applicable requirements of the Flood Insurance
Rate Maps (FIRM) dated August 2, 1995 or August 23, 2000, as amended,
and any future revisions thereto.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Prior
to approval by the City of a stormwater management design plan, each
owner shall submit a maintenance agreement and maintenance plan in
accordance with the following:
1. Responsible party. The owner shall be responsible
for the operation and maintenance of such measures and shall pass
such responsibility to any successor owner, unless such responsibility
is transferred to the City or to another governmental entity in accordance
with Division 5.
2. Requirement for maintenance agreement and plan. If
a stormwater management design plan requires structural or non-structural
measures, the owner shall execute a stormwater maintenance agreement
prior to the City granting final approval of the plan, or any plan
of development or other development for which a permit is required
under this Chapter. The agreement shall be recorded in the office
of the St. Louis County Recorder of Deeds and shall run with the land.
A copy of the recorded agreement shall be submitted to the Frontenac
Building Commissioner/Zoning Administrator.
3. Required elements for maintenance agreement and plan. The stormwater maintenance agreement and plan shall be in a form
approved by the City, and shall, at a minimum:
a. Designate for the land development, the owner, governmental agency,
or other legally established entity (responsible party) which shall
be permanently responsible for maintenance of the structural or non-structural
measures required by the plan;
b. Pass the responsibility for such maintenance to successors in title;
c. Grant the City the right of entry for the purposes of inspecting
all stormwater BMPs at reasonable times and in a reasonable manner,
which includes the right to enter a property when the City has a reasonable
basis to believe that a violation of this Chapter is occurring or
has occurred and to enter when necessary for abatement of a public
nuisance or correction of a violation of this Chapter;
d. Ensure the continued performance of the maintenance obligations required
by the plan and this Chapter through a maintenance plan (which may
be an attachment to the actual maintenance agreement), and shall include
a list of inspection and maintenance tasks, a schedule for routine
inspection and maintenance, actions to be taken when maintenance is
required, and other items listed in the Stormwater Design Manual.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Performance Guarantee Required. No permits shall be issued
unless the applicant furnishes a cash escrow or a letter of credit
as approved by the Frontenac City Attorney. The amount of the escrow
or letter of credit shall be determined by the City based on the cost
of the work and scope of work. This is to ensure that action can be
taken by the City, at the applicant's expense, should the applicant
fail to initiate or maintain those measures identified in the approved
stormwater management design plan (after being given proper notice
and within the time specified by the City. If the City takes such
action upon such failure by the applicant, the City shall collect
from the applicant the difference should the amount of reasonable
cost of such action exceed the amount of the security held.
B. Term Of Performance Guarantee. The performance escrow or letter of credit furnished pursuant to this Section, or the unexpended or unobligated portion thereof, shall be returned to the applicant within sixty (60) days of issuance by the City of a stormwater certificate of completion in accordance with Section
506.390, or the final acceptance of the permanent stormwater BMP by the City.
C. Term Extended For Initial Maintenance. At the discretion
of the City, the performance escrow or letter of credit may be extended
beyond the time period specified above to cover a reasonable period
of time for testing the practices during storm events and for initial
maintenance activities. For the purposes of this Section, the time
shall not exceed two (2) years.
D. Partial Release Of Escrow. The City shall have the discretion
to adopt provisions for a partial pro rata release of the performance
escrow or letter of credit on the completion of various stages or
phases of development.
[Ord. No. 2010-1621 §1, 4-20-2010]
All applicants are required to submit as-built plans for any
permanent stormwater management facilities located on site after final
construction is completed. The plan must show the final design specifications
for all stormwater management facilities, meet the criteria for as-built
plans in the Stormwater Design Manual, and be sealed by a registered
professional engineer. A final inspection by the City is required
before any performance escrow or letter of credit will be released.
[Ord. No. 2010-1621 §1, 4-20-2010]
The City has the ability to require a fee to support local plan
review, inspection and program administration. Each owner seeking
approval of a stormwater management concept plan or stormwater management
design plan shall pay a fee for the City consulting engineer review
and expenses and additional expenses for staff time for site visits
and meetings, and shall pay a fee for each inspection in amounts according
to the fee schedule contained in Division 3.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. The
owner of a stormwater practice required by this Chapter may offer
for dedication any such stormwater practice, together with such easements
and appurtenances as may be reasonably necessary, as provided herein:
1. Preliminary determination by the City. Upon receipt
of such offer of dedication by City, the City shall make a preliminary
determination that the dedication of the practice is appropriate to
protect the public health, safety and general welfare, and furthers
the goals of the City's stormwater management program and/or associated
watershed plans. The City shall forward its determination to MSD,
if appropriate. Prior to making its determination, the City shall
inspect the practice to determine whether it has been properly maintained
and is in good repair.
2. Acceptance by City. The City may accept the offer
of dedication by adoption of a resolution. The document dedicating
the stormwater BMP shall be recorded in the office of the Clerk of
the Circuit Court for the City.
3. Owner to provide documentation. The owner, at his
sole expense, shall provide any document or information requested
by the City in order for a decision to be reached on accepting the
practice.
4. Section
506.300, Post-Construction Performance Criteria for Stormwater Management.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Stormwater BMP Maintenance. All stormwater BMPs shall be
maintained in accordance with the approved and deeded stormwater maintenance
agreement and stormwater maintenance plan. The design of stormwater
facilities shall incorporate maintenance accommodation and long-term
maintenance reduction features in accordance with the latest version
of the Stormwater Design Manual.
B. Velocity Dissipation. Velocity dissipation devices shall
be placed at discharge locations and along the length of any outfall
to provide non-erosive flow velocity from the structure to an adequate
receiving stream or channel so that the natural physical and biological
characteristics and functions of the receiving stream are maintained
and protected.
C. Discharges To Adjacent Property. Concentrated discharges
from land disturbance, including from stormwater practices, shall
not be discharged closer than ten (10) feet to adjacent developed
property without adequate conveyance in a natural stream or storm
sewer system. The City may require drainage easements where stormwater
discharges must cross an adjacent or off-site property before reaching
an adequate conveyance.
D. Individual Lots Not Separate Land Development. Residential,
commercial or industrial developments shall apply these stormwater
management criteria to land development as a whole. Individual residential
lots in new subdivisions shall not be considered separate land development
projects, but rather the entire subdivision shall be considered a
single land development project.
E. Location Of Stormwater Facilities On Lots. Stormwater facilities
within residential subdivisions that serve multiple lots and/or a
combination of lots and roadways shall be on a lot owned and maintained
by an entity of common ownership, unless an alternative arrangement
is approved by the City. Stormwater practices located on individual
lots shall be maintained by the lot owner or, at the discretion of
the City, be placed within an easement and maintained by an entity
of common ownership.
F. Hydrologic Computation Assumptions. Hydrologic parameters
shall reflect the ultimate land development and shall be used in all
engineering calculations. All pre-development calculations shall consider
woods and fields to be in good condition, regardless of actual conditions
at the time of application.
G. Authorization To Discharge To MS4. If runoff from a land
development will flow to a municipal separate storm sewer system (MS4)
or other publicly-owned storm sewer system, then the applicant shall
obtain authorization from the system's owner to discharge into the
system. MSD may require the applicant to demonstrate that the system
has adequate capacity for any increases in peak flow rates and volumes.
H. Compliance With Federal And State Regulations. All stormwater
facilities and conveyance systems shall be designed in compliance
with all applicable State and Federal laws and regulations, including
the Federal Clean Water Act and all applicable erosion and sediment
control and flood plain regulations. To the extent practical, stormwater
facilities shall not be located in areas determined to be jurisdictional
waters through Section 404 of the Federal Clean Water Act and/or applicable
State regulations.
I. Protect Public Health, Safety And General Welfare. The design
of stormwater BMPs shall consider public health, safety, and general
welfare. These considerations include, but are not limited to: preventing
flooding of structures and travelways; preventing standing water in
facilities, manholes, inlets, and other structures in a manner that
promotes breeding of mosquitoes; preventing attractive nuisance conditions
and dangerous conditions due to velocity or depth of water and/or
access to orifices and drops; and preventing aesthetic nuisances due
to excessive slopes, cuts and fills, and other conditions.
J. Adherence To Stormwater Design Manual. All stormwater BMPs
shall be designed to the standards of the most current version of
the Stormwater Design Manual, unless the City grants the applicant
a waiver or the applicant is exempt from such requirements.
K. Treat Entire Land Disturbance. The stormwater design shall
provide for treatment of runoff from the entire land disturbance,
to the extent practical.
L. Landscape Plan. The design of stormwater BMPs shall include
a landscape plan detailing both the vegetation to be in the practice
and how and who will manage and maintain the vegetation. The landscape
plan shall be prepared in accordance with the Stormwater Design Manual.
M. Pretreatment. Each stormwater BMP shall have an acceptable
form of water quality pretreatment in accordance with the pretreatment
requirements found in the current Stormwater Design Manual.
N. Stormwater Authority Discretion. If hydrologic, geologic,
topographic, or land use conditions warrant greater control than that
provided by the minimum control requirements, the City may impose
additional requirements deemed reasonable and necessary to control
the volume, timing, rate and/or quality of runoff. The City may restrict
the use of certain stormwater BMPs, require pretreatment above the
minimum standards in the Stormwater Design Manual, and/or require
a stormwater pollution prevention plan in certain circumstances. These
include, but are not limited to, stormwater generated from stormwater
hotspots, stormwater discharges that are conveyed with non-stormwater
discharges, and stormwater discharged in important ground water management
areas or areas where geologic conditions are conducive to ground water
contamination (e.g., karst).
O. Replicating Pre-Development Hydrology. Stormwater management
designs shall preserve the natural hydrologic functions, stream channel
characteristics, and ground water recharge of the pre-developed site,
to the extent practical. This shall be accomplished by treating runoff
at the source, disconnecting impervious surfaces, preserving or enhancing
natural flow paths and vegetative cover, preserving or enhancing natural
open spaces and riparian areas, and other measures that replicate
pre-development hydrologic conditions. The City shall exercise discretion
in the application of this standard, especially in cases of infill
development, redevelopment, or other unique circumstances.
P. Treatment Of Off-Site Stormwater. Off-site stormwater conveyed
through a land development shall be conveyed in a manner that does
not increase upstream or downstream flooding. Off-site stormwater
shall be conveyed around on-site stormwater BMPs, unless the facilities
are designed to manage the off-site stormwater. The City may allow
credits for treating off-site stormwater.
Q. Stream And Wetland Crossings. All stream and wetland crossings
subject to State stream and wetland regulations shall minimize impacts
on streams and wetlands, to the extent practical and achievable, by
crossing streams and wetlands at a right angle, reducing the footprint
of grading and fill, and utilizing bridges, open bottom arches, spans,
or other structures that do not restrict or alter stream or wetland
hydrology. If culverts are placed within stream and wetlands, at least
one (1) culvert shall be countersunk or otherwise placed to allow
the formation of a natural channel or wetland bottom to allow movement
of aquatic organisms.
[Ord. No. 2010-1621 §1, 4-20-2010; Ord. No. 2011-1648 §1, 4-19-2011]
A. Structural
and non-structural stormwater BMPs shall be used to prevent or minimize
water quality impacts from land development. The applicant shall be
subject to the requirements of (1), (2) and (3) below if the project's
land disturbance is less than one (1) acre; otherwise, the applicant
shall follow St. Louis Metropolitan Sewer District (MSD) requirements
in Chapter 4 of "Rules and Regulations and Engineering Design Requirements
for Sanitary Sewer and Stormwater Drainage Facilities" February 2006,
or latest revision.
1. Water quality volume standard. Structural practices
shall be designed to capture and treat, at a minimum, the water quality
volume (WQv) in cubic feet. The WQv shall be computed as follows:
WQv = [P x DI]/12, where:
P = 1-year 24-hour rainfall depth of 2.5 inches
DI = is the increase in impervious cover (square feet)
|
Land disturbance that qualifies as redevelopment, and exceeds
two thousand (2,000) square feet of increased impervious area shall
also meet one (1) of the following criteria: [Ord. No. 2024-2030, 1-30-2024]
|
a. Reduce existing site impervious cover by at least twenty percent
(20%);
b. Provide treatment for at least twenty percent (20%) of the site's
pre-development impervious cover through stormwater BMPs designed
in accordance with the criteria in the Frontenac Stormwater Regulations
and the Stormwater Design Manual;
c. Contribute to a watershed project that is acceptable to the City;
or
d. Any combination of impervious cover reduction, stormwater treatment,
and contribution to a watershed project acceptable to the City.
2. Technology standard. Structural and non-structural
practices shall be selected from the Stormwater Technology Table in
the Stormwater Manual and sized and designed according to the standards
in the manual.
3. Additional criteria for stormwater hotspots. In
addition, stormwater discharges from stormwater hotspots may require
the use of specific structural, non-structural, and/or pollution prevention
practices, including enhanced pre-treatment. Discharges from a stormwater
hotspot shall not be infiltrated without enhanced pre-treatment, as
approved by the City.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Protection
of stream channels from bank and bed erosion and degradation shall
be provided by using all of the approaches in (1), (2) and (3), listed
below:
1. Treatment of stream buffers. Stream buffers (protected through other regulations and permits, and Chapter
506) shall be preserved, restored, and/or reforested.
2. Erosion prevention. Erosion prevention measures
such as energy dissipation and velocity control shall be used at all
outfalls.
3. Extended detention. The design shall provide twenty-four
(24) hour extended detention storage of the one (1) year, twenty-four
(24) hour return frequency storm event.
[Ord. No. 2010-1621 §1, 4-20-2010]
A. Land
disturbance that discharges to sensitive waters and wetlands, as designated
in the Stormwater Design Manual, shall meet enhanced criteria. These
may include, but are not limited to:
1. Control of temperature increases for discharges to designated cold
water fisheries;
2. Enhanced control of nutrients and sediment for discharges to drinking
water reservoirs, lakes and/or wetlands;
3. The control of impacts to wetland hydrology, including limiting fluctuations
to the natural or pre-development wetland hydrology; and
4. Enhanced bacteriological or pollutant controls for discharges to
impaired waters, as designated in the most recent 303(d) list produced
by EPA or the appropriate State agency.
In these cases, the City may require additional storage, treatment,
filtering, infiltration, or other techniques. The use of non-structural
practices shall be used to the maximum extent practical to meet enhanced
criteria.
In making its determination to apply enhanced criteria, the
City shall consider cumulative impacts and also the land development's
adherence to the land use plans and policies of the City, including
the promotion of infill and redevelopment in particular areas.
[Ord. No. 2010-1621 §1, 4-20-2010]
Every applicant shall provide for stormwater management as required
by this Chapter, unless a written request for a waiver is filed. Prior
to applying for a waiver request, the applicant must demonstrate that
all reasonable options to comply with the Chapter have been exhausted.
The request for a waiver must be in writing. The City shall respond
in writing by granting or denying the waiver in full, or granting
the waiver with any necessary conditions or mitigation measures to
protect public health, safety, and the environment. The applicant
shall note any full or partial waivers, and conditions imposed by
the City, on the stormwater management design plan. Any expenses incurred
by the City for review of the waiver application must be paid by the
applicant.