Stormwater Control Ordinance For Lands Within the ZonePrepared by the
Section 1
1.1 Statutory Authority The Municipal Land Use Law, , and the Soil Erosion and Sediment Control Act, , provide
the statutory authority for this ordinance.
1.2 Findings of Fact
It is hereby determined that:
1. Water bodies, roadways, structures and other property within, and downstream of, the
municipality are at times subjected to flooding;
2. Flooding is a danger to the lives and property of the public and is also a danger to the
natural resources of the municipality and the region;
3. Land development projects and activities alter the hydrologic response of watersheds
resulting in increased stormwater runoff rates and volumes, increased flooding, increased stream channel
erosion, and increased sediment transport and deposition;
4. Stormwater runoff produced by the land development contributes to increased quantities
of water-borne pollutants;
5. Increases of stormwater runoff, soil erosion and non-point source pollutants have
occurred in the past as a result of land development, and constitute deterioration of the water resources of
the municipality and downstream municipalities;
6. Stormwater runoff, soil erosion and nonpoint source pollution can be controlled and
minimized by the regulation of stormwater runoff from development projects.
7. The State of Surface Water Quality Standards ( ) establish surface water quality
standards and antidegradation policies applicable to all surface waters of the state and these standards and
antidegradation policies provide reasonable guidance to municipalities for the regulation of stormwater
runoff for purposes of protecting surface water resources from degradation.
8. A portion of this municipality lies within the and hence, some surface waters located
in this municipality are tributary to area. The waters of the Area are all classified as Category
waters, for purposes of applying the State of 's surface water quality antidegradation policies.
9. The existing uses of the Area, which are to be protected in accordance with the State's
surface water quality antidegradation policies, are dependent on maintaining good water quality and natural
rates and volumes of flow. These uses include the following:
a. to preserve, restore and enhance, in their natural ecosystem, all species of animals and
plants that are endangered or threatened with becoming endangered;
b. to perpetuate the migratory bird resource;
c. to preserve a natural diversity and abundance of fauna and flora on refuge lands;
d. to provide an understanding and appreciation of fish and wildlife ecology and people's
role in their environment, and to provide refuge visitors with high quality, safe, wholesome and enjoyable
recreational experiences oriented toward wildlife to the extent these activities are compati ble with the
purposes for which the refuge was established.
e. Within the Area, to manage so as to maintain the wilderness resource for future
benefit and enjoyment; to preserve the wilderness character of the biological and physical features of the
area; to provide opportunities for research, solitude and permitted recreational uses; to ensure that the
works of man remain substantially unnoticeable.
10. Stormwater runoff, soil erosion, stream channel erosion and nonpoint source pollution,
due to land development activities within the Area, have resulted in a deterioration of the water
resources of the municipality and downstream municipalities, including the water resources of the Area.
11. Increased stormwater runoff rates and volumes, and the sediments and pollutants
associated with stormwater runoff, from future development projects within the , have the potential to
adversely affect the municipality's streams and water resources, and the streams and water resources of
downstream municipalities, including the Category waters of the Area.
It is therefore determined that it is in the public interest to regulate the discharge of stormwater
runoff from land development projects and other construction activities, within the , as provided in this
ordinance, in order to control and minimize increases in stormwater runoff rates and volumes and to control
and minimize soil erosion, stream channel erosion, and nonpoint source pollution associated with
stormwater runoff.
1.3 Purpose
It is the purpose of this ordinance to establish minimum stormwater management requirements and
controls:
1. To reduce artificially induced flood damage to public health, life, and property;
2. To minimize increased stormwater runoff rates and volumes from any new land
development.
3. To minimize the deterioration of existing watercourses, culverts and bridges, dams and
other structures;
4. To induce water recharge into the ground where geologically favorable conditions exist;
5. To prevent an increase in nonpoint source pollution;
6. To maintain the integrity of stream channels for their biological functions, as well as for
drainage and other purposes;
7. To minimize the impact of development upon streambank and streambed stability;
8. To reduce erosion from any development or construction project;
9. To preserve and protect water supply facilities and water resources by means of
controlling increased flood discharges, stream erosion, and runoff pollution;
10. To reduce stormwater runoff rates and volumes, soil erosion and nonpoint source
pollution, wherever possible, from lands that were developed without stormwater management controls
meeting the purposes and standards of this ordinance; and
11. To minimize public safety hazards at any stormwater detention facility constructed
pursuant to subdivision or site plan approval.
1.4 Applicability
This ordinance shall be applicable to any major subdivision or site plan application, as defined in
the Municipal Land Use Law, or any project, as defined by the Soil Erosion and Sediment Control Act,
located within the municipality and within the Zone, as shown on Attachment 1.
1.5 Compatibility with Other Permit and Ordinance Requirements
Development approvals issued pursuant to this ordinance are to be considered an integral part of
development approvals under the subdivision and site plan review process and do not relieve the applicant
of the responsibility to secure required permits or approvals for activities regulated by any other applicable
code, rule, act or ordinance. In their interpretation and application, the provisions of this ordinance shall be
held to be the minimum requirements for the promotion of the public health, safety, and general welfare.
This ordinance is not intended to interfere with, abrogate, or annul any other ordinances, rule or
regulation, stature, or other provision of law. Where any provision of this ordinance imposes restriction
different from those imposed by any other ordinance, rule or regulation, or other provision of law,
whichever provisions are more restrictive or impose higher standards shall control.
In addition, in the event a regional stormwater management plan is prepared and formally adopted
for the , this ordinance shall be amended to ensure consistency with that regional plan.
1.6 Severability
If the provisions of any article, section, subsection, paragraph, subdivision or clause of this
ordinance shall be judged invalid by a court of competent jurisdiction, such order of judgment shall not
affect or invalidate the remainder of any article, section, subsection, paragraph, subdivision or clause of this
ordinance.
Section 2
Definitions
Unless specifically defined below, or in the Municipal Land Use Law ( ), or in the Soil Erosion
and Sediment Control Act ( ), or in 's Surface Water Quality Standards ( ), words or phrases used in
this ordinance shall be interpreted so as to give them the meaning they have in common usage and to give
this ordinance its most reasonable application.
"Agricultural development" means land uses normally associated with the production of food,
fiber, and livestock for sale. For purposes of this ordinance, such uses shall not include the development of
land for the processing or sale of food and the manufacture of agriculturally related products.
"Detention basin" means an impoundment area made by construction and embankment, or
excavation a pit, or both, for the purpose of temporarily storing stormwater.
"Detention facility" means a detention basin or alternative structure designed to temporarily retain
stormwater runoff.
"Flood plain" means the area inundated by 's regulatory flood including the water course that
creates it. 's regulatory flood means 's adopted Flood Hazard Area Design Flood along streams for
which has an adopted flood hazard area and floodway study, and the 100-year flood along non-
delineated streams for which has not delineated a flood hazard area.
"Floodway" means the channel of a natural stream and portions of the flood hazard areas adjoining
the channel, which are reasonably required to carry and discharge the flood water or flood flow of any
natural stream. For this ordinance, the term floodway refers to both the delineated floodway along streams
which have state adopted flood hazard area and floodway studies, and the area between approved
encroachment lines located on both sides of non-delineated streams for which no state adopted flood hazard
area and floodway study exists.
"Freshwater wetlands" means an area that is inundated or saturated by surface water or
groundwater at a frequency and duration sufficient to support, and that under normal circumstances does
support, a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known
as hydrophytic vegetation; provided, however, that in designating a wetland, the municipality shall use the
three parameter approach (that is, hydrology, soils and vegetation) enumerated in the "Federal Manual for
Identifying and Delineating Jurisdictional Wetlands" and any subsequent amendments thereto.
" Area" means the portion of the municipality, within the watershed of , for which it is the
policy of the municipality to preserve all lands in their natural state, to the greatest extent possible . Section
of this ordinance specifies the lands that constitute the Area.
"Infiltration facility" means any structure or device designed to infiltrate retained water to the
subsurface and which is not an injection well. These facilities may be above grade or below grade. Above
grade infiltration facilities temporarily impound surface water runoff above grade, to a maximum depth of
two feet, with all retained water infiltrated to recharge. Below grade infiltration faciliti es temporarily retain
surface water runoff below grade in the interstices of coarse aggregate, or other porous media, with all
retained water infiltrated to recharge. Examples of below grade infiltration facilities incl ude gravel surface
parking areas and gravel filled trenches.
"Nonpoint source pollution" means pollution from any source other than from any discernible,
confined, and discrete conveyances, and shall include, but not be limited to, pollutants from agricultural,
silvicultural, mining, construction, subsurface disposal and urban runoff sources.
"Recharge" means the replenishment of underground water reserves.
"Retention Basin" means an impoundment area with a permanent pool made by construction and
embankment, or excavation a pit, or both, for the purpose of temporarily storing storm water. A retention
basin is also called a "wet basin" or "wet detention basin".
"Stormwater runoff" means flow on the surface of the ground, resulting from precipitation.
"Treatment train" means a sequence of structures or devices through which runoff passes before
exiting the project site. The combined characteristics of the individual structures or devices shall sati sfy the
performance requirements associated with the no net increase provisions of this ordinance.
"Water Quality Storm" means a one-year frequency, 24-hour storm, using the Type III rainfall
distribution recommended for New Jersey by the US Soil Conservation Service or a storm of 1.25 inches of
rainfall falling uniformly in two hours.
"Wet basin" means a detention basin designed to retain some water on a permanent basis. Another
name for wet basin is " detention basin" or "retention basin".
Section 3
Technical Standards
3.1 No Net Increase Provisions
1. No net increase in nonpoint source pollution - Stormwater control systems shall be
designed so that there is no degradation of water quality in the receiving watercourse, due to nonpoint
source pollution associated with stormwater runoff. 's Surface Water Quality Standards, , shall be
used as guidelines for this determination.
2. No net increase in sediment loadings - Stormwater control systems shall be designed to
reduce, to the maximum extent possible, the Total Suspended Solids (TSS) generated by the development
for storm events up to the water quality design storm and to retain, as closely as possible, the pre-
development hydrologic response of the site, and the watershed..
3. No net increase in stormwater runoff rates and stream channel erosion - Stormwater
control systems shall be designed so that, to the maximum extent possible, the post-development
stormwater runoff rates, from the site, and at any point in the watershed between the site and the , are no
greater than pre-development rates, in order to retain as closely as possible, the pre-development
hydrologic response of the site and the watershed.
4. No net increase in stormwater runoff volumes - Stormwater control systems shall be
designed so that all stormwater runoff is infiltrated into the ground for the 1.25 inch, 24-hour storm, using
the Type III rainfall distribution recommended for by the US Soil Conservation Service. In addition, the
first 1.25 inches of stormwater runoff from all larger storms shall also be infiltrated into the ground.
3.2 Procedures for Measuring Compliance with the No Net Increase Provisions of the Ordinance
1. Hydrologic/hydraulic analyses shall be prepared and submitted demonstrating that the
post-development stormwater runoff rates do not exceed the standards set forth in this ordinance for the
water quality storm and the 2-, 10-, and 100-year storms.
The hydrologic and hydraulic analyses shall follow generally accepted methodologies for
evaluating stormwater runoff rates and volumes, including the methodologies specified in 's Stream
Encroachment Manual, the USDA/SCS's TR-55 and TR-20 methodologies, and the US Army Corps of
Engineers' HEC-1 model.
For infiltration facilities proposed to meet the no net increase provisions of this ordinance, the
results of soil tests demonstrating the suitability of the area's soils for infiltration of runoff shall also be
provided.
2. A nonpoint source pollutant loading analysis shall be prepared and submitted,
demonstrating that the post development nonpoint source pollutant and sediment loadings do not exceed
the standards set forth in this ordinance, as a result of the proposed land development project.
In preparing the required analysis it shall be acceptable to utilize the average removal efficiency
statistics provided in the Stormwater and Nonpoint Source Pollution Control Best Management Practices
Manual, dated 19 , and any subsequent revisions thereto, prepared by the Department of
Environmental Protection and the New Jersey Department of Agriculture.
3.3 Mitigation Measures
If the natural or existing physical characteristics of the project site preclude achievement of any of
the above no net provisions, the municipality may grant a variance from strict compliance with the specific
no net increase provisions that are precluded, provided that acceptable mitigation measures are provided.
However, to be eligible for a variance, the applicant must demonstrate to the satisfaction of the munic ipal
engineer that the immediately downstream waterways will not be subject to:
1. Deterioration of existing culverts, bridges, dams, and other structures;
2. Deterioration of their biological functions, as well as for drainage and other purposes;
3. Streambank or streambed erosion or siltation;
4. Increased threat of flood damage to public health, life and property.
Furthermore, where partial compliance with a specific no net increase provision is possible, the
municipal engineer will direct the applicant to satisfy a reduced performance criterion. Mitigation m easures
will be required to compensate for the unfulfilled component of the no net increase provision.
In all cases, however, those no net provisions that are not precluded by the site's physical
characteristics, shall be met. Mitigation measures may include, but are not limited to, the fol lowing:
1. If one or more of the no net increase provisions of this ordinance cannot be met on-site,
and a regional stormwater management plan for the has not been adopted by a regional entity, then the
applicant shall meet those no net provisions of this ordinance, precluded by the site's physical
characteristics, by employing one or more of the following mitigation measures, in this order of preference.
The purchase, or donation of, privately owned lands within the Area, that are not currently protected by
's Freshwater Wetlands Protection Act Rules or 's Flood Hazard Area Control Regulations, said lands to
be dedicated for preservation and/or reforestation, in accordance with Attachment 2, " Mitigation
Requirements." The purchase, or donation of, privately owned lands within the , but not within the
Area, to be dedicated for preservation and/or reforestation, in accordance with Attachment 2, "
Mitigation Requirements." Mitigation on previously developed properties, public or private, that currently
lack stormwater management facilities designed and constructed in accordance with the purposes and
standards of this ordinance, in accordance with Attachment 2, " Mitigation Requirements." Cash
contributions to fund stormwater management related studies within the Zone, including regional
wetland delineation studies, stream-monitoring studies for water quality and macro invertebrates, stream
flow monitoring, and threatened and endangered species studies. The amount of the cash contribution shall
be determined in accordance with Attachment 2, " Mitigation Requirements."
2. If one or more of the "no net increase" provisions of this ordinance cannot be met on-site,
and a regional stormwater management plan for the been adopted by a regional entity, the applicant
may elect to meet the no net increase provisions of this ordinance, precluded by the site's physical
characteristics, by financially or otherwise participating in the implementation of the regional stormwater
management plan, in accordance with a specific formula for participation, specified by the regional entity.
3.4 Area The following lands constitute the Area and the preservation requirements associated with
those lands:
1. Lands within the - Trees, shrubs, grasses and other existing vegetation within standard
transition areas of freshwater wetlands located along state open waters located in the shall not be
disturbed except in accordance with a valid transition area waiver issued by , pursuant to the
Freshwater Wetlands Protection Act Rules ( ).
2. Lands Proximate to the Top of - Trees, shrubs, grasses and other existing vegetation
within 25 feet of the top of the of any State open water within the shall not be disturbed unless the
applicant demonstrates that there is no alternative to the proposed project design which would eliminate or
further minimize the disturbance.
The 25 foot distance shall be increased to 50 feet of the top of the channel bank if the stream
corridor is a critical part of the habitat supporting a threatened or endangered species of plant or a current
population of any species of threatened endangered animal on a permanent or temporary basis, for any
purpose such as resting, breeding or feeding, during any portion of its life cycle; or if the stream corridor
lies within documented, historic habitat for threatened or endangered species of animals, which habitat
remains suitable for breeding, resting or feeding by those species of animal during any portion of its life
cycle.3. Additional Lands - Any land areas, other than those described above, that lie within 150
feet of any intermittent or perennial stream within the , or within 150 feet of freshwater wetlands
associated with those streams, shall also be preserved to the maximum extent possible, to serve as a natural
buffer area to the 's streams and wetlands, and to assist in meeting the no net increase provisions of this
ordinance.
3.5 Detention/Retention Basins for Stream Flooding and Erosion Control
The standards for detention/retention basins shall be as follows:
1. Detention and/or retention basins shall be designed to capture and retain all stormwater
runoff from the site's impervious surfaces during the water quality storm, and from all smaller storms. The
runoff shall then be slowly released in accordance with the requirements presented in Section . "For
detention basins."
2. The post-development peak runoff rate for the two-year storm event shall be 50 percent
of the pre-development peak runoff rate and the post-development peak runoff rate for the 10- and 100-year
storm events shall be 75 percent and 80 percent of the pre-development peak runoff rates, respectively.
3. Most water quality control and infiltration measures will also provide some benefit in
runoff peak control. Where water quality control or infiltration measures are instituted, appropriate
adjustments to the post-development peak runoff may be incorporated by the introduction of modified
runoff coefficients (e.g., time of concentration, initial abstraction, SCS runoff curve number). Procedures
used by the applicant to adjust runoff coefficients to take credit for the detention properties of
miscellaneous stormwater control measures (i.e., measures not specifically designed for providing runoff
peak control) must be approved by the municipal engineer.
4. The US Soil Conservation Service procedures, such as "Urban Hydrology for Small
Watersheds", Technical Release No. , or other generally accepted methodologies, may be used for
computing pre-development and post-development runoff rates and volumes. For the purposes of choosing
runoff curve numbers, the curve numbers presented in Attachment 3, "Curve Numbers for Use in the ,
shall be used.
5. In computing pre-project construction runoff, all significant land features, such as ponds,
depressions, or hedgerows, which increase the ponding factors, shall be accounted for.
6. The applicant shall provide plans and calculations, which show that the discharge
attributable to the proposed project will not cause erosion along the flow path between the outfall and the
receiving water body.
7. Soil erosion and sediment control shall be provided in accordance with Standards for Soil
Erosion and Sediment Control promulgated by the State Soil Conservation Committee pursuant to
administered by the local Soil Conservation District.
8. If detention basins or other detention facilities are provided through which water passes
at times other than following rainfall, the municipal engineer shall be consulted concerning design crite ria.
It will be necessary for detention requirements to be met, despite the necessity of passing certain low flows.
This applies to all on-stream or on-line detention basins.
9. Detention basins located in freshwater wetlands may be allowed only in accordance with
the Freshwater Wetlands Protection Act, , and any rules adopted pursuant thereto.
10. Any detention facility that impounds water through the use of an artificial dike, levee or
other barrier and raises the water level five feet or more above the usual mean low water height when
measured from the downstream toe-of-dam to the emergency spillway crest is classified as a dam and
subject to the dam safety standards, . All such dams must be designed, constructed, operated and
maintained in compliance with the rules of .
3.6 Water Quality Control and Infiltration Measures
In most instances, the water quality control and infiltration performance requirements of this
ordinance will be satisfied by multiple structures or devices (see Section 3.7 of this ordinance).
Furthermore, most structures or devices will achieve both a water quality control and infiltration benefit.
Compliance with the no net increase provisions of the ordinance will be based on a project-wide
summation of runoff characteristics. The applicant will show how the collection of structures or devices
incorporated in the stormwater management plan will jointly satisfy the performance requirements of this
ordinance.
In order to meet the no net increase provisions of this ordinance with regard to stormwater runoff
volumes, sediment loadings and other nonpoint source loadings, stormwater management facilities shall
provide for the control of a water quality design storm, in accordance with the following basic principles:
1. Infiltration facilities shall be designed to achieve the recharge of at least 60 percent
(tabulated on an annual basis) of direct rainfall. This will be achieved by the implementation of measures
which will retain and infiltrate all runoff generated for storms up to the 1.25 inch, 24-hour storm, using the
Type III rainfall distribution recommended for by the US Soil Conservation Service. In general,
multiple infiltration facilities will be required to collectively satisfy the infiltrati on requirement.
2. Concentrations of stormwater volume shall be minimized by designing small impervious
surface drainage units.
3. Runoff shall be attenuated at the source.
4. Land uses shall be classified into "Harmfulness Classes", as shown in Attachment 4,
"Stormwater Management for Water Quality Improvement and Infiltration in the ," dated
__________________, and prepared by . Stormwater runoff from Harmfulness Class 1 surfaces shall be
directed through one or more water quality devices prior to infiltration.
5. Water quality and infiltration device treatment trains shall be designed that utilize the
natural qualities of the landscape.
6. Due to the difficulties associated with their design and maintenance, detention/retention
basins are not suitable as infiltration facilities. Therefore, retention volumes associated with basins ma y not
be used to comply with the no net increase provision of this ordinance as it regards runoff volume.
However, retention basins (or "wet basins") may be used to satisfy the water quality requirements of this
ordinance.
7. The incorporation of porous pavement systems, including porous asphalt pavement and
modular paving block systems, are encouraged as a means of lowering the effective runoff curve number
for a developed site. By increasing the pervious ness of the developed site, benefits will be achieved in the
form of reduced infiltration and peak runoff control requirements.
Utilizing the above design principles, a stormwater management plan shall be designed for the
project area, utilizing the stormwater control "Best Management Practices" (BMPs) presented in
Stormwater and Nonpoint Source Pollution Control Best Management Practices Manual, dated December
1994, and any subsequent revisions thereto, prepared by the Department of Environmental Protection
and the Department of Agriculture.
In preparing the project's stormwater management plan, the design procedure presented in
Attachment 4, "Stormwater Management for Water Quality Improvement and Infiltration in the ," dated
__________________and prepared by , shall be followed.
The no net increase provision of this ordinance shall be deemed to have been met regarding
nonpoint source pollutants and sediments if the estimated post-development nonpoint source annual
pollutant loadings after water quality treatment have been reduced prior to discharge by the following
percentages for the nonpoint source pollutant indicator parameters.
Percent Removal of Post-development NPS Pollutant Loadings
Nonpoint Source For New Developments on For Sites Undergoing Indicator Parameters Previously
Undeveloped Land Redevelopment
Total Suspended Solids (TSS) 90% or greater 45% or greater
Total Nitrogen (TN) 65% or greater 30% or greater
Total Phosphorous (TP) 75% or greater 25% or greater
Zinc (Zn) 90% or greater 20% or greater
Lead (Pb) 90% or greater 50% or greater In estimating the removal efficiencies of the water quality control measures proposed, it shall be
acceptable to utilize the average removal efficiency statistics provided in the Stormwater and Nonpoint
Source Pollution Control Best Management Practices Manual, dated __________________, and any
subsequent revisions thereto, prepared by the Department of Environmental Protection and the
Department of Agriculture.
3.7 Requirements for Selected Stormwater Management Measures
1. For detention basins:
a. Detention basins shall not be located within the floodway of any watercourse in the ;
b. The construction of detention basins in flood plains should be avoided, but where this is
unavoidable, a special examination to determine adequacy of a proposed detention facility during extreme
storm events shall be required. This examination is required to determine what effects, if any, the tail
waters created by the flood plain have on the outflow from and effective storage within the detention
facility. All designs of basins in flood plains, therefore, should be based upon an accurate and thorough
determination of tail water effects resulting from runoff from the site and the watershed contributing to the
flood plain.
c. Beginning at the time of peak storage in the basin for the water quality design storm, no
more than 90 percent of the total peak storage volume is released over an 18-hour period for residential
developments or over a 36-hour period for commercial developments. Longer drawdowns are permissible,
but in no case shall the draw down period exceed 72 hours. The rate of release shall be as uniform as
possible;
d. The minimum outlet diameter, width or height is three inches. If this minimum outlet size
does not allow for the detention times required in this ordinance, then alternative techniques for the
removal of TSS prior to discharge into the basin shall be provided; and
e. The species of native or non-intrusive exotic vegetation used in the basin shall be
approved by the municipality and the appropriate County Soil Conservation District.
2. For wetponds/retention basins:
a. Such basins shall not located within the floodway of any watercourse in the .
b. The volume of the permanent pool shall be at least three times the volume of the expected
runoff from the water quality design storm;
c. The pool shall be shallow enough to avoid thermal stratification and deep enough to
minimize algal blooms and resuspension of decomposing organics and other previously deposited
materials;
d. The flow from the contributory drainage area shall be sufficient in dry weather to
maintain the permanent pool during the summer months and prevent stagnation;
e. The configuration of the permanent pool shall promote maximum sedimentation and
minimize plug flow;
f. Where feasible, native fish stock shall be used to control mosquitoes; and
g. There shall be no adverse effects to the receiving watercourse resulting from differences
in temperature between the discharge and the waters in the receiving watercourse.
3. For artificial wetlands:
a. Where feasible, the wetlands shall be created around a standing pool of water at least 6
feet in depth;
b. At least one-half of the perimeter of the water area shall be graded to form a 10 to 20 foot
wide shallow bench for aquatic emergents;
c. The surface area of the artificial wetlands shall be at least three percent of the total area
contributing flow into the artificial wetland;
d. Vegetation shall be commercial wetland plant stock, either live plants or dormant
rhizomes, instead of transplants from existing wetlands areas or seeding;
e. At least two hardy and rapid colonizing indigenous primary wetlands species shall be
planted over 30 percent of the total shallow water area. Each species shall be planted in three or four
monospecific stands with individual plants spaced two to three feet apart. Up to three less aggressively
colonizing secondary wetlands species shall be randomly distributed in clumps around the perimeter of the
marsh; and
f. At least 25 percent of the total surface area of a basin designed exclusively to act as a
shallow marsh shall be open water with a depth of at least two feet in order to provide habitat for waterfowl
and other marsh birds.
4. For vegetated or biofilter swales:
a. The water velocity shall not exceed two feet per second (FPS) to allow for settlement of
TSS during the water quality design storm. The slope shall not be less than 0.5 percent so that positive
drainage is maintained. The swale shall be of sufficient length to allow for settlement of TSS taking int o
consideration the velocity, depth of flow and expected loading of TSS;
b. Where feasible, vegetation shall be used in the swale to filter out the TSS and to provide
a secondary treatment by absorption of pollutants leached into the soil. Vegetation used in the swale shall
be native or non-intrusive exotic species approved by the County Soil Conservation District;
c. If the swale is designed to provide infiltration, the soil texture shall be sand, loamy sand
or sandy loam as defined by the US Department of Agriculture and there shall be a minimum of three feet
separation between the bottom of the swale and the seasonal high water table; and
d. The swale shall be used internally within the stormwater collection system and in
conjunction with other methods such as vegetated filter strips to increase their effectiveness; and
5. For above grade infiltration facilities:
a. There shall be at least three feet vertical separation between the bottom of the facilit y and
the seasonal high water table;
b. The maximum depth of impoundment shall be two feet;
c. The soil texture of the upper six inches of the facility (i.e., immediately below the surface
layer of turf, gravel, paving blocks, etc.) shall be sand, loamy sand or sandy loam, as described by the US
Department of Agriculture. As necessary, the applicant will import appropriate cover material to comply
with this requirement;
d. The surface of the facility may be stabilized by turf, gravel, porous asphalt pavement,
modular paving blocks, or other measures approved by the municipal engineer;
e. The entire volume of the runoff impounded during a storm shall be recharged to
groundwater within 72 hours; and
f. The design of the infiltration facility shall be based on infiltration rates measured using
procedures outlined in EPA guidance (citation) or other method acceptable to the municipal engineer.
6. For below grade infiltration facilities:
a. Where porous media are used (e.g., gravel surfaced parking areas, gravel filled trenches),
the applicant shall provide documentation of the in-place porosity of the media for purposes of estimating
the retained runoff volume;
b. A media separation (e.g., geotextile or graded sand filter) shall be used to maintain the
integrity of the interface between porous media and the native soil;.
c. The design of the facility shall be based on infiltration rates measured using procedures
outlined in EPA guidance (citation) or other method acceptable to the municipal engineer;
d. The entire volume of the runoff impounded during a storm shall be recharged to
groundwater within 72 hours. Standpipes are required in all below grade infiltration facilities for the
purpose of inspecting water levels; and
e. As required by the municipal engineer, runoff shall be treated to remove TSS and other
nonpoint source pollutants prior to discharge to a below grade infiltration facility. Treatment may consist of
a vegetated buffer strip, sediment trap, etc.
7. For porous asphalt pavement:
a. The soil beneath the pavement shall be sand, loamy sand or sandy loam as defined by the
US Department of Agriculture;
b. The porous pavement shall be buffered with vegetative screening to prevent the intrusion
of aeolin sand and silt;
c. The permittee shall undertake a strict maintenance schedule including but not limited to
vacuum sweeping on a weekly basis and high-pressure water washing on a monthly basis;
d. The porous pavement shall be used in light traffic areas subject to automobiles only and
is marked by a sign restricting traffic to only passenger vehicles;
e. No asphalt sealer may be used; and
f. No sand is used during periods of snow and ice.
8. For sediment traps and oil/grease separators: The drainage areas served shall be less than
one-tenth of an acre in size and the applicant's comprehensive maintenance plan is approved by the
municipality.
9. For modular paving block systems:
a. The upper six inches of soil beneath the paving system shall be sand, loamy sand or
sandy loam as defined by the US Department of Agriculture. As necessary, the applicant will import
appropriate cover material to comply with this requirement;
b. In-place infiltration rates shall be measured using procedures outlined in EPA guidance
(citation) or other method acceptable to the municipal engineer;
c. Permissible paving blocks include, but are not limited to bricks bedded in sand (minimum
one-half inch separation between blocks) and interlocking concrete blocks with open work cutouts;
d. Paving block systems shall be used in pedestrian and in light traffic areas subject to
automobiles only and marked by a sign restricting traffic to only passenger vehicles;
e. The permittee shall undertake a semi-annual program of inspection and maintenance; and
f. Modification of paved areas to provide benefits associated with below grade infiltration
facilities can be obtained by constructing pavement over a layer of coarse aggregate or similar porous
media.
3.8 Planning and Design Standards for Maintenance and Repair
1. The goal for the planning and design of a stormwater management facility is for its
operation with the least practical amount of maintenance. To accomplish this, the facility shal l be
developed to eliminate avoidable maintenance tasks, minimize the long term amount of regular
maintenance, facilitate the performance of required maintenance tasks, and reduce the potential for
extensive, difficult, and costly remedial or emergency maintenance efforts.
2. Strong, durable, and noncorrodible materials, components, and fasteners shall be used to
reduce required maintenance efforts. These include but are not limited to lightweight noncorrodible metal s
such as aluminum for trash racks, orifice plates, and access hatches; hardy, disease resistant grasses for
bottoms and side slopes as prescribed by Soil Erosion and Sediment Control standards administered by the
local Soil Conservation District; reinforced concrete for outlet structures and inlet headwalls; and gabions
for channel and outlet linings.
3. Detention facilities shall be designed to minimize propagation of insects, particularly
mosquitoes.
4. Detention facilities should be designed in a harmonious and attractive manner.
5. Detention facility outlets shall be designed to function without manual, electric or
mechanical controls.
6. Maintenance shall be required as part of all stormwater management plans. Specific
maintenance techniques and schedules shall be provided for each type of system used on the site. If
maintenance of the system will be the responsibility of a person other than a State, county or municipal
agency, then the maintenance plan approved by the municipality shall be recorded upon the deed of record
for the property.
a. The maintenance plan shall include the name, address and telephone number of the party
or parties responsible for long-term maintenance. Documentation of their assumption of this responsibility
shall be submitted as part of the permit application. The transfer of maintenance responsibility to indi vidual
property owners in residential subdivisions is prohibited except through a homeowner’s association
agreement.
b. written maintenance and repair records for all stormwater management systems shall be
maintained for at least five years by the person's identified in (6) above and shall be provided to the
municipality upon request.
c. Maintenance of artificial wetlands shall include, but not be limited to:
i. documented visual inspection of all components of the system at least once every six
months;
ii. documented removal of silt, litter and other debris from all catch basins, inlets and
drainage pipes at least once every six months, or upon noticeable buildup; and
iii. vegetation removal and replacement, as necessary, at least once a year.
d. Maintenance of detention basins shall include, but not be limited to:
i. documented visual inspection of all components of the system at least once every six
months;
ii. documented removal of silt, litter and other debris from all catch basins, inlets and
drainage pipes at least once every six months or upon noticeable buildup;
iii. documented maintenance, including grass cutting, and necessary replacement of all
landscape vegetation within the basin at least once a year; and
iv. documented aeration of basin bottoms at least once a year and scraping and replanting at
least once every five years to prevent the sealing of the basin bottom.
e. Maintenance of wet ponds/retention basins shall include, but not be limited to, annual
documented monitoring of water quality, dissolved oxygen, vegetative growth, temperature and fish
population, for a period of three years to ensure that the wet pond/retention basin is working as intended.
3.9 Safety Measures
Safety measures are to be incorporated in the design of all stormwater and infiltration control
projects. These may include but not be limited to fencing, warning signs/stadia rod indicating depth at
lowest point, and outlet structures designed to limit public access.
Section 4
Requirements for a Site Development Stormwater Plan
4.1 Submission of Site Development Stormwater Plan 1. Whenever an applicant seeks municipal approval of a development subject to this
ordinance, the applicant shall submit all of the required components of the Checklist for the Site
Development Stormwater Plan as part of the submission of the application for subdivision or site plan
approval.
2. The applicant shall demonstrate that the project meets the standards set forth in this
ordinance.
3. The applicant shall submit five copies of the materials listed in the checklist for site
development stormwater plans in accordance with Section 4.3 of this ordinance.
4.2 Site Development Stormwater Plan Approval
The applicant's plans for development shall be reviewed as a part of the subdivision or site plan
review process by the municipal board or official from which municipal approval is sought. That municipal
board or official shall consult the engineer retained by the Planning and/or Zoning Board (as appropriate) to
determine if all the checklist requirements have been satisfied and to determine if the project m eets the
standards set forth in this ordinance.
4.3 Checklist Requirements
The following information shall be required:
1. Topographic Base Map - A topographic base map of the site shall be submitted which
extends a minimum of 200 feet beyond the limits of the proposed development, at a scale of 1"=200' or
greater, showing 2-foot contour intervals. The map shall indicate existing surface water drainage;
marshlands and other wetlands; pervious or vegetative surfaces; existing man-made structures; roads;
bearing and distances of property lines; and significant natural and manmade features not otherwise shown.
The reviewing engineer may require upstream tributary drainage system information as necessary.
2. Environmental Site Analysis - A written and graphic description of the natural and man-
made features of the site and its environs shall be provided. This description should include a discussion of
soil conditions, slopes, wetlands, and vegetation on the site. Particular attention should be given to unique,
unusual, or environmentally sensitive features and to those that provide particular opportunities or
constraints for development.
3. Project Description and Site Plan(s) - A map (or maps) at the scale of the topographical
base map indicating the location of existing and proposed buildings, roads, parking areas, utilities,
structural facilities for stormwater management and sediment control, and other permanent structures. The
map(s) shall also clearly show areas where alterations occur in the natural terrain and cover, including
lawns and other landscaping, and seasonal high groundwater elevations. A written description of the site
plan and justification of proposed changes in natural conditions may also be provided.
4. Stormwater Management Facilities Map - The following information shall be provided
and illustrated on a map of the same scale as the topographic base map, shall be included: a.total area t o be
paved or built upon, proposed surface contours, estimated land area to be occupied by the stormwater
management facilities and the type of vegetation thereon, and details of the proposed plan to control and
dispose of surface water.
b. details of all stormwater management facility designs, during and after construction,
including discharge provisions, discharge capacity for each outlet at different levels of detention and
emergency spillway provisions with maximum discharge capacity of each spillway.
5. Calculations
a. comprehensive hydrologic and hydraulic design calculations for the pre-development and
post-development conditions for the design storms as specified in Section 3 of this ordinance.
b. When the proposed stormwater management control measures (e.g., infiltration basins)
depend on the hydrologic properties of soils, then a soils report shall be submitted. The soils report shall be
based on on-site boring logs or soil pit profiles. The number and location of required soil borings or soil sits
shall be determined based on what is needed to determine the suitability and distribution of soil types
present at the location of the control measure.
6. Maintenance and Repair Plan
a. The design and planning of the stormwater management facility shall meet the objectives
of Section 3.8.
b. Maintenance procedures shall be detailed which ensure the continuation of the intended
function of the facility.
c. Maintenance and repair plans for stormwater management facilities shall identify the
parts or components of the facility that need to be maintained, and when repairs are required, the equipment
and skills or training necessary. Plans for stormwater management facilities shall detail the acce ssibility of
maintenance personnel and equipment. Costs and sources of funds shall be identified when possible.
d. A schedule shall be developed of when and how often maintenance will occur to maintain
proper function of the stormwater management facility. To reduce the potential for extensive, difficult, and
costly remedial or emergency maintenance efforts, the schedule of maintenance activities shall i nclude
inspections to ensure proper performance of the facility between scheduled cleanouts.
e. Where a stormwater management facility is used for sediment control during
construction, a debris and sediment disposal site shall be confirmed before the facility is constructed. The
disposal site may or may not be at the site of the proposed development. The responsible party shall
demonstrate that he or she is capable of financing the removal and disposal of debris and sediment before
the facility is operating. Disposal site(s) shall be included in the Soil Erosion and Sediment Control Plan
and certified by the local Soil Conservation District.
f. Provisions for periodic review and evaluations to determine the overall effectiveness of
the maintenance programs and the need for revised or additional maintenance procedures, personnel and
equipment shall be included in the facilities maintenance and repair plan.
Section 5
Continued Maintenance, Repair and Safety
5.1 Applicability Projects subject to review as specified in Section 1.4 of this ordinance shall comply with the
requirements of Sections 5.2 and 5.3
5.2 Responsibility for Continued Maintenance, Repair and Safety
1. The requirements of this section do not apply to stormwater management facilities that
are dedicated to and accepted by the municipality or another governmental agency. Responsibility for
operation and maintenance of stormwater management facilities, including periodic removal and disposal
of accumulated particulate material and debris, shall remain with the property owner, unless assumed by a
governmental agency, with permanent arrangements that it shall pass to any successor or owner. If portions
of the land are to be sold, legally binding arrangements shall be made to pass the basic responsibility to
successors in title. These arrangements shall designate for each project the property owner, governmental
agency, or other legally established entity to be permanently responsible for inspection and maintenance,
hereinafter in this section referred to as the responsible person.
2. Prior to granting approval or as a condition of final subdivision or site plan approval to
any project subject to review under this ordinance, the applicant shall enter into an agreement with the
municipality to ensure the operation and maintenance of the stormwater management facility. In cases
where property is subdivided and sold separately, a homeowners' association or similar permanent entity
shall be established as the responsible person absent an agreement by a governmental agency to assume
responsibility. It shall be demonstrated to the municipality that a proposed new responsible entity has the
capability to complete and finance necessary maintenance.
3. In the event that the stormwater management facility becomes a danger to public safety
or public health, or if it is in need of maintenance, the municipality shall so notify the responsible person in
writing. Upon receipt of that notice, the responsible person shall have fourteen (14) days to effect
maintenance and repair of the facility in a manner that is approved by the municipal engineer or his
designee. If the responsible person fails or refuses to perform such maintenance and repair, the municipality
may immediately proceed to do so and shall bill the cost thereof to the responsible person.
5.3 Continued Maintenance and Repair Procedures
1. Preventive maintenance procedures are required to maintain the intended operation and
safe condition of the stormwater management facility by reducing the occurrence of problems and
malfunctions. To be effective, preventive maintenance shall be performed on a regular basis and include
such routine procedures as training of staff, periodic inspections, grass cutting and fertilizing, silt and
debris removal and disposal, upkeep of moving parts, elimination of mosquito breeding habitats, pond
maintenance, and review of maintenance and inspection work to identify where the maintenance program
could be more effective.
2. Corrective maintenance procedures are required to correct a problem or malfunction at a
stormwater management facility and to restore the facility's intended operation and safe condition. Based
upon the severity of the problem, corrective maintenance must be performed on an as-needed or emergency
basis and include such procedures as structural repairs, mosquito extermination, removal of debris,
sediment and trash removal which threaten discharge capacity, erosion repair, snow and ice removal, fence
repair and restoration of vegetated and no vegetated lining.
5.4 Penalties
Any responsible person who violates any portion of Section 5.2.3 or Section 5.3 of this ordinance
shall be subject to the following penalties:
Section 6
Effective Date
This ordinance shall take effect upon final passage by the Township Committee.
ATTACHMENT 1
Map of the ZoneATTACHMENT 2 Requirements
ATTACHMENT 4
Stormwater Management for Water Quality Improvement and Infiltration in the
