[R.O. 2004 §520.010; CC 1990 §520.010; Ord. No. 638 §1, 1-4-1988; Ord. No. 787 §1, 12-16-1993]
This Chapter seeks to provide those standards, criteria, procedures
and controls necessary to minimize the harmful physical and economic
effects of erosion and flooding from stormwater within or directed
toward the City of Pevely. This is to be accomplished through the
requirement of special measures to mitigate erosion both during and
after development and the retention and controlled discharge of the
runoff from any property whereon any grading, excavation, filling
or other disturbance of the natural vegetation or any construction,
erection or alteration of a building or structure is to be undertaken.
[R.O. 2004 §520.020; CC 1990 §520.020; Ord. No. 638 §1, 1-4-1988; Ord. No. 787 §1, 12-16-1993; Ord. No. 1172 §1, 8-4-2008]
A.
DEVELOPED PROPERTY
PROPERTY
UNDEVELOPED PROPERTY
Definitions. As used in this Chapter, the following terms
shall have these prescribed meanings:
Any tract of land in the City of Pevely whereon any grading,
excavation, filling or other disturbance of the natural vegetation,
or any construction, erection or alteration of a building or structure
has been undertaken.
Any tract of land in the City of Pevely.
Any tract of land in the City of Pevely whereon neither grading,
excavation, filling or other disturbance of the natural vegetation,
nor any construction, erection or alteration of a building or structure
has been undertaken.
B.
General. A stormwater runoff control permit is required for all development. Except as provided in Subsection (F) of this Section, it shall be unlawful for any person to develop or improve on any property within the City unless there is in force a stormwater runoff control permit issued as required under the provisions of this Chapter.
C.
Construction Or Alteration Of Buildings. Except as provided in Subsection (F) of this Section, it shall be unlawful for any person to construct any new building or structure or to enlarge or otherwise alter any existing building or structure on any property within the City unless there is in force a stormwater runoff control permit issued as required under the provisions herein.
D.
Change In Ownership Of Property. The provisions of this
Chapter shall apply to a property when the ownership of the property
changes and a stormwater runoff control permit has not been previously
issued.
E.
Change Or Disturbance Of Terrain. Except as provided in Subsection (F)(4) of this Section, it shall be unlawful for any person to clear, grade, excavate, fill, remove topsoil from or change the contour of any land in the City unless there is in force a stormwater runoff control permit issued under the provisions of this Chapter.
F.
Exceptions. The provisions of this Chapter shall not apply
to:
1.
Any reconstruction, repair or alteration of any existing building
or structure when no land, trees, shrubs, grass or other vegetation
is to be disturbed, destroyed or removed.
2.
Any previously subdivided lot zoned "A" or Residential for one (1)
single-family dwelling.
3.
The purchase or acquisition of any undeveloped property zoned "A"
or Residential. However, development of such property will require
a stormwater runoff control permit.
4.
(Reserved)
5.
The planting, trimming, pruning or removal of trees, shrubs, grass,
weeds, vegetation, ground cover or other plant material when such
actions are incidental to and part of the normal maintenance of land
and property in the City of Pevely.
6.
(Reserved)
[R.O. 2004 §520.030; Ord. No. 787 §1, 12-16-1993]
A.
General Standards.
1.
Zoning classification and permitted land use determine the stormwater
retention requirements for any given property. Minimum lot size and
percent imperviousness are major factors in determining the future
runoff from a property. An additional volume of stormwater will be
caused to leave a property due to development thereon. The volume
of stormwater which must be retained in accordance with the provisions
of this Chapter is the difference between the volume of water expected
to leave the property in an undeveloped condition (roughly five percent
(5%) impervious) and the volume of water which will be caused to leave
the property due to all development (existing and proposed) thereon.
2.
Runoff rates for all categories of projects shall be evaluated by
the Rational Formula. The runoff coefficients in the following table
for a storm event with a fifty (50) year (frequency) and an assumed
twenty (20) minute inlet time shall be used to calculate runoff volumes.
|
Average C.I. Factors in Cubic Feet per Second per Acre
(CFS/Acre)
20 Minute Inlet Time
| ||||||
|---|---|---|---|---|---|---|
|
Zoning District
|
Use
|
% Imp.1
|
C
|
C.I. Factors2
| ||
|
25-Yr.
|
50-Yr.
|
100-Yr.
| ||||
|
A - Agricultural
|
All Uses
|
5
|
0.37
|
2.00
|
2.18
|
2.37
|
|
R-1 - Residential
|
Single-Family
|
45
|
0.54
|
2.92
|
3.19
|
3.46
|
|
All Other Uses
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
R-2 - Residential
|
Single Family
|
47
|
0.548
|
2.96
|
3.23
|
3.51
|
|
Two-Family
|
47
|
0.548
|
2.96
|
3.23
|
3.51
| |
|
All Other Uses
|
75
|
0.665
|
3.59
|
3.92
|
4.26
| |
|
R-3 and R-4 - Residential
|
Single-Family
|
49
|
0.556
|
3.01
|
3.28
|
3.56
|
|
Two-Family
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Multiple-Family
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
All Other Uses
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
PRD - Planned Residential Development
|
Same as R-3
|
Same as R-3
|
Same as R-3
|
Same as R-3
|
Same As R-3
|
Same as R-3
|
|
MH - Mobile Home Park
|
Single-Family
|
49
|
0.556
|
3.01
|
3.28
|
3.56
|
|
Mobile Homes
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Nursery/Day Nursery
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Kindergarten
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
Primary School
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Jr. High School
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Sr. High School
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Collegiate
|
60
|
0.60
|
3.24
|
3.54
|
3.84
| |
|
Church
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
Fire Stations
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
Public/Not for Profit Libraries
|
70
|
0.645
|
3.48
|
3.81
|
4.13
| |
|
B-1 - Commercial
|
Residential
|
Same as R-3
|
Same as R- 3
|
Same as R - 3
|
Same as R-3
|
Same as R- 3
|
|
All Other Uses
|
85
|
0.705
|
3.81
|
4.16
|
4.51
| |
|
B-2 - Commercial
|
Residential
|
Same as R-3
|
Same as R-3
|
Same as R-3
|
Same as R-3
|
Same as R-3
|
|
All Other Uses
|
85
|
0.705
|
3.81
|
4.16
|
4.51
| |
|
B-3 Planned Commercial
|
Same as B-1 & B-2
|
Same as B-1
& B-2
|
Same as B-1
& B-2
|
Same as B-1
& B-2
|
Same as B-1
& B-2
|
Same as B-1
& B-2
|
|
I-1 Light Industrial
|
All Uses
|
90
|
0.73
|
3.94
|
4.31
|
4.67
|
|
I-2 Heavy Industrial
|
All Uses
|
90
|
0.73
|
3.94
|
4.31
|
4.67
|
|
PID - Planned Industrial Development
|
Same as I-1 & I-2
|
Same as I-1
& I-2
|
Same as I-1
& I-2
|
Same as I-1
& I-2
|
Same as I-1
& I-2
|
Same as I-1
& I-2
|
|
NOTES:
| |
|---|---|
|
1
|
The percent impervious (% Imp.) values were based upon the minimum
lot size requirements specified for each use included in the draft
"Revised Zoning Code and Subdivision Regulations of Pevely, Missouri"
dated September 30, 1992.
|
|
2
|
The C.I. factors were derived from the U.S. Weather Bureau Technical
Paper No. 40: "Rainfall Frequency Atlas of the United States for Durations
from Thirty (30) Minutes to Twenty-Four (24) Hours and Return Periods
from One (1) to One Hundred (100) Years."
|
B.
Retention Facilities. In general, retention facilities shall
be provided with obvious and effective control strategies. The following
shall be considered in determining the effectiveness and safety of
these facilities in relation to the intent and purpose of this Section.
1.
(Volume of runoff from the developed property) = C.I. Factor x Area
of property (in acres) x 30 minutes x 60 seconds/minute.
2.
(Volume of runoff from the property in undeveloped condition) = 2.00
cfs/acre x Area of property (in acres) x 30 minutes x 60 seconds/minute.
3.
Volume of retention for the developed property = (Volume of runoff
from developed property) - (Volume of runoff from the property in
an undeveloped condition)
4.
Tributary (Q) peak runoff to basin.
5.
Balanced maximum outflow rate from the low-flow structure.
6.
Ratios of inflow to outflow rates.
7.
Sizing of the overflow facilities.
8.
Stability of retention dikes.
9.
Safety features.
10.
Maintenance features.
C.
Open Dry Reservoirs.
1.
Wet weather ponds or dry reservoirs shall be designed with proper
safety, stability and ease of maintenance features and shall not retain
stormwater to a depth greater than four (4) feet if specifically permitted
by site plan review by the Planning and Zoning Commission in consideration
of a special demonstrated need and special provisions to avoid safety
hazards of such greater hazards of such greater depths.
2.
Maximum side slopes for grass-edged reservoirs shall not exceed one
(1) foot vertical for two (2) feet horizontal (2:1) unless adequate
measures are included to provide for the stability of these slopes.
3.
In no case shall the limits of maximum ponding elevation be closer
than thirty (30) feet horizontally from any building and less than
two (2) feet vertically below the lowest sill elevation.
4.
The entire reservoir area shall be seeded, fertilized and mulched,
sodded or paved prior to release of escrows.
D.
Permanent Lakes Used For Retention.
1.
Permanent lakes with fluctuating volume controls may be used as retention
areas provided that the limits of maximum ponding elevations are no
closer than thirty (30) feet horizontally from any building and less
than two (2) feet below the lowest sill elevation of any building.
2.
Maximum fluctuation from permanent pool elevation to maximum ponding
elevation shall be three (3) feet.
3.
Special consideration shall be given to measures to ensure the safety
of small children in the design of permanent lakes especially when
located in residential areas.
E.
Parking Lots Used For Retention.
1.
Retention is permitted in parking lots to a maximum depth of twelve
(12) inches.
2.
In no case should the maximum limits of ponding be designed closer
than ten (10) feet from a building unless proper provision is made
for the waterproofing of the building and for pedestrian accessibility.
3.
The minimum freeboard from the maximum ponding elevation to the lowest
sill elevation shall be two (2) feet.
4.
Closed retention tanks. Facilities which are fully
enclosed to retain stormwater may be of any depth.
F.
Discharge Systems.
1.
The design discharge (Q) for the low-flow pipe shall not exceed the
twenty-five (25) year (frequency) twenty (20) minute duration (inlet
time), runoff from the tributary area for five percent (5%) imperviousness
(2.0 C.F.S. per acre). The maximum discharge shall be designated to
take place under total anticipated design-head conditions.
2.
Low-flow pipes shall not be smaller than four inches (4) in diameter
to minimize maintenance and operating problems, except in parking
lot and roof retention where minimum size of the opening shall be
designed specifically for each condition. The low-flow pipe shall
be provided with a bar-screen on a minimum 2:1 slope to reduce blockage
by debris.
3.
The overflow opening or spillway shall be designed to accept the
total peak runoff of the improved tributary area, with discharge velocity
not to exceed five (5) feet per second unless special provisions are
made.
4.
Proper engineering judgment shall be exercised in analysis of secondary
routing of discharge of greater intensity than the design twenty-five
(25) year frequency in order to avoid economic losses or damage downstream.
Review with twenty-five (25) and fifty (50) year frequency is recommended.
5.
Sizing of the system below the control structure shall be for the
total improved peak runoff tributary to the structure with no allowance
for retention, with discharge velocity not to exceed five (5) feet
per second unless special provisions are made.
G.
Erosion Control Principles. In general, the basic principles
of erosion control that the developer should be aware of include the
following:
1.
Clearing, grading and excavating should be performed on ground on
which construction will commence within twelve (12) months.
2.
Cut or fill slopes should not be left steeper than two (2) horizontal
to one (1) vertical unless slope stabilization is planned.
3.
Excavations and fills near adjoining property boundaries shall be
supported to protect the adjoining property from erosion, sliding
or settling.
4.
No fill is to be placed where excess sediment may erode upon the
premises of another or soil placed adjacent to the bank of a channel
as to create bank failure or reduce the natural capacity of the stream.
5.
Permanent final vegetation and structures shall be installed as soon
as practical.
6.
Provisions shall be made to effectively accommodate the increased
runoff caused by changed surface conditions during development by
designing and providing for stormwater retention facilities.
H.
Erosion Control Practices. Erosion control practices must
be incorporated within all grading plans submitted to the Planning
and Zoning Commission and must comply with the provisions set forth
in Section 3012.0 Protection of Adjoining Property of the 1990 BOCA
Code. These practices may include any of the following or others submitted
by the developer after consultation with the Planning and Zoning Commission:
1.
Diversion channel. A channel with a supporting ridge
on the lower side constructed across a slope. The purpose of the diversion
channel is to direct stormwater over a hillside in such a manner as
to result in minimum erosion and therefore minimum deposition of sediment
downstream. The side slopes of the diversion channel shall be three
(3) horizontal to one (1) vertical or flatter.
2.
Grade stabilization structures. Structures that
stabilize the grade or control head cuttings in channels which are
installed to control erosion in natural or artificial channels. These
structures reduce the advance of gullies and slow the erosion process.
Examples include overflow structures of concrete, metal, rock riprap
or other suitable material used to lower water from one level to another.
These structures are applicable where the watercourse elevation must
be dropped over a very short horizontal distance. Adequate protection
must be provided to prevent erosion or scour upstream, downstream
and sides of the overflow structure.
3.
Grassed waterways. Natural or constructed waterways
sloped or graded to carry away runoff. The side slopes of a grassed
waterway must be a minimum four (4) horizontal to one (1) vertical.
4.
Mulching. Applying material to the soil to enhance
the growth of plant cover and to retard runoff and erosion. Satisfactory
mulching materials include:
5.
Seeding/sodding. Stabilizing potentially erosive
areas by fertilizing and seeding or by sodding. Fescue and fescue
mixtures should be applied to the rate of thirty (30) pounds per acre;
agricultural lime should be applied at the rate of two (2) tons per
acre.
Should sod be used for stabilization, the sod strips should
be laid on the contour, not up and down the slope. Furthermore, sod
should be laid from the bottom up the slope and should be laid snug
with even joints to retard erosion and rutting.
[R.O. 2004 §520.040; Ord. No. 787 §1, 12-16-1993; Ord. No. 1172 §2, 8-4-2008]
All stormwater discharge pipes shall be designed based on a
fifty (50) year rainfall frequency at a minimum.
[R.O. 2004 §520.050; Ord. No. 787 §1, 12-16-1993]
A.
Retention
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.
B.
Silt
and debris connected both with early construction and with general
erosion from the site and elsewhere in the watershed after construction
shall be removed periodically from the retention area and control
structure in order to maintain full storage capacity.
C.
The
responsibility of maintenance of the retention facilities in subdivision
projects shall remain with the developer until such time as applicable
escrows are released. Upon release of escrows the maintenance responsibility
shall be vested in the trustees of the subdivision by virtue of the
trust indenture. The indenture of the trust shall clearly indicate
resident responsibility for maintenance in cases of projects without
common ground.
D.
The
responsibility of maintenance of the retention facilities in single
owner development projects shall remain with the general contractor
until final inspection of the development is performed and approved
and a legal occupancy permit is issued. After legal occupancy of the
project, the maintenance of retention facilities shall be vested with
the owner of the project.
[R.O. 2004 §520.060; Ord. No. 787 §1, 12-16-1993; Ord. No. 794 §1, 4-21-1994; Ord. No. 885 §1, 2-2-1998; Ord. No. 1172 §3, 8-4-2008]
A.
Requirement For Stormwater Runoff Control Permit. A stormwater permit is required for all development except as provided in Section 420.020(F). A fee for the issuance of a stormwater permit shall be paid to the City in accordance with the following schedule:
|
|
Total Cost of Construction
|
Stormwater Permit Fee
|
|---|---|---|
|
|
$1.00 to $999.00
|
$0.00
|
|
|
$1,000.00 to $100,999.00
|
$500.00 (5 hr. review)
|
|
|
$101,000.00 to $500,999.00
|
$1,000.00 (10 hr. review)
|
|
|
$501,000.00 and over, amount of charge will be set by the Board
of Aldermen.
|
|
|
The developer shall be liable for any extended reviews, any
subsequent reviews or for any meetings which may be requested by the
developer or his/her representative.
| |
|
|
The full balance of all engineering reviews shall be paid prior
to the issuance of a stormwater runoff control permit.
| |
|
| ||
B.
Requirement For Building Or Grading Permit. No permit shall be issued to construct, erect or alter any building or structure or to clear, grade, excavate, fill, remove topsoil from or change the contour of any property within the City until a stormwater runoff control plan has been submitted to and approved by the City Engineer and a stormwater runoff control permit has been issued by the City of Pevely in accordance with the provisions of this Chapter, except as provided in Section 420.020(F).
C.
Requirement For Occupancy Permit. No permit shall be issued for occupancy of any building or structure within the City until a stormwater runoff control permit has been issued by the City of Pevely in accordance with the provisions of this Chapter, except as provided in Section 420.020(F).
D.
Procedure.
1.
Application for an approved stormwater runoff control plan, as required,
shall be submitted to the Administrator by the owner of the land prior
to the time any work subject to this Chapter is begun on the land.
2.
The application for a stormwater runoff control permit must include
a stormwater runoff control plan.
3.
Upon receipt of any application and plan, the City Administrator
with the advice of the City Engineer shall consider the plan in light
of the provisions of this Chapter and shall approve the plan, disapprove
the plan or approve the plan with modifications, noting thereon any
changes that will be required.
4.
Upon approval of the plan, the City will issue a stormwater runoff
control permit. In the case where the plan has been approved with
modifications, a permit will not be issued until the City has received
written confirmation from the developer that the modification has
been incorporated into the stormwater runoff control plan and will
be incorporated into the actual development.
5.
The City shall promptly notify the applicant of the City's decision
on a plan. Failure of the City to act on any plans submitted within
seventy-five (75) days after they have been properly filed should
be deemed to constitute approval of the plans. Any approved plan shall
be issued, dated, and bear the manual signature of the City Administrator.
E.
Submission Requirements.
1.
All plans and specifications submitted for review and/or approval
shall be prepared by or under the direct supervision of a registered
professional engineer licensed in the State of Missouri and shall
meet the minimum standards and requirements of the City and other
applicable authorities. Each of the plan, profile and special drawing
sheets for a project shall bear a legible stamp of the professional
engineer in charge.
2.
In order to facilitate review of plans, all projects shall be submitted
with a letter of transmittal which shall include the name of project,
name and address of owner or developer, name, address and telephone
number of engineer, and clarification as to the purpose of submittal.
[R.O. 2004 §520.070; Ord. No. 787 §1, 12-16-1993; Ord. No. 1172 §4, 8-4-2008]
A.
The
stormwater runoff control permit and associated stormwater runoff
control plan shall be subject to all provisions of this Chapter relating
to enforcement, violations and penalties. In addition, a corporate
surety bond conditioned upon carrying out all and every part of approved
plans for at least the sum estimated to be the full costs of carrying
out such plans or a cash escrow upon the same conditions and in the
same amount shall be furnished by City whenever such costs exceed
five hundred dollars ($500.00). The bond or escrow shall be released
upon proper completion of all of the requirements of such approved
plans.
B.
Enforcement. This Chapter shall be enforced by the City
Administrator with the assistance and cooperation of other officials
including the City Engineer. If the City Administrator finds that
any of the provisions of this Chapter are being violated, he/she shall
notify in writing the person responsible for such violation, indicating
the nature of the violation and ordering the action necessary to correct
it. He/she shall take any other action authorized by law to ensure
compliance with or to prevent violation of the provisions of this
Chapter.
C.
Violations And Penalties.
1.
Violations of this Chapter shall include, but are not limited to,
the following:
a.
Any activity of proceeding not in accordance with the procedures,
requirements, standards or other provisions of this Chapter.
b.
No owner, or agent of the owner, of any land located within a subdivision
of the City of Pevely shall knowingly or with intent to defraud, transfer,
sell, agree to sell or negotiate to sell that land by reference to
or by other use of a plat of any purported subdivision of the land
before the final subdivision plat has been approved by the Planning
and Zoning Commission and Board of Aldermen in accordance with this
Chapter and recorded by the Recorder of Deeds of the County.
c.
Failure to obtain the approvals and permits required by this Chapter
and to comply with their terms and conditions.
2.
Those chargeable, singly or jointly, with violations of this Chapter
shall include, but are not limited to, the following:
a.
Those who commit, assist in or otherwise participate in a violation.
b.
The owner or other persons who maintain the building, premises, property
or other place where the violation has been committed or exists.
c.
The developer, agent, architect, contractor or any other person who
performs work or enters into a contract for work in violation of this
Chapter.
3.
(Reserved)
