A. All development shall be provided with a stormwater management plan consisting of, but not limited to, inlets, manholes and pipes where necessary for proper surface drainage. The system shall be adequate to carry off and/or store the stormwater and natural surface runoff, which originates not only within the property in question, but also beyond the tract boundaries.
Where possible, all runoff within a site shall ultimately leave the site in the same watershed in which it originated and shall be released in such a manner so as to not overload existing drainage systems, create flooding creating a need for additional drainage facilities on other public or private lands or increase predevelopment erosion of adjacent lands.
The peak rate of runoff from a site during and after development shall not exceed the predevelopment peak rate of runoff. Development upstream of known areas of problem flooding shall be required to further reduce the peak rate of runoff below the pre-developed rate. Where the upstream tributary drainage area exceeds fifty (50) acres, the standards established in the Technical Manual for Stream Encroachment, NJAC 7:13-2.8, Stormwater Management, NJDEP, shall govern.
The increase in volume of runoff from a site, during and after development, from the predevelopment total of volume of runoff shall be minimized. Runoff control measures shall be used to retard or reduce runoff and increase recharge. Depending on the soil characteristics natural and artificial recharge area and systems should be employed whenever practical to minimize the volume of surface water runoff. These include, but are not limited to, infiltration pits, dry wells, infiltration trenches and the extensive use of sheet flow through vegetated areas. The use of such measures will not eliminate or reduce, even partially, the need for other requirements of this section.
The peak rate of runoff for areas of up to twenty (20) acres shall be calculated by the rational method or derivatives. The equation for the rational method is as follows:
Qp = CIA
Where
Qp = The peak runoff rate in cubic feet per second (cfs).
C.= The runoff coefficient.
I= The average rainfall intensity in inches per hour in/hr), occurring at the time of concentration Tc (min).
Tc = The time of concentration in minutes (min).
A.= The size of the drainage area in acres (ac).
1. Typical runoff coefficients values) are provided in the Technical Manual for Stream Encroachment, prepared by the New Jersey Department of Environmental Protection (NJDEP), page 51, Table 3.1-2(B1). Runoff coefficient C used in the rational formula shall be weighted if there is more than one (1) kind of land use within the drainage basin under consideration.
2. The time of concentration (tc) is defined as the time required for water to reach the point in question from the most hydraulically distant point in the basin. Time of concentration (to) shall be estimated from the Nomograph for the Determination of Time of Concentration, prepared by the State of New Jersey Highway Authority. The analysis shall also consider the procedure outline in Section 3.12(c) for Technical Release (TR) Number 55, Urban Hydrology for Small Watersheds, United States Department of Agriculture, Soil Conservation Series, as supplemented and amended (SCS method).
3. Rainfall intensity as a function of duration and storm recurrence frequency shall be based upon geographically appropriate data as depicted in the plates in Technical Paper Number 25, Rainfall Intensity Duration-Frequency Curves, United States Department of Commerce, Weather Bureau, as supplemented and amended. Intensity curves may be based on local rainfall frequency data, where available. In all instances, a minimum time of concentration of five (5) minutes should be used,
4. The peak rate of runoff for areas greater than twenty (20) acres shall be calculated by hydrograph analysis method as outlined in the latest edition of Urban Hydrology for Small Watersheds Technical Release Number 55 (TR55).
Runoff volume calculation:
Runoff volume shall be calculated by the hydrograph analysis method as outlined in the latest edition of Urban Hydrology for Small Watershed Technical Release Number 55 (SCS method). This method shall be used for watersheds having drainage areas greater than twenty (20). For drainage areas of less than twenty (20) acres, the rational method triangular hydrograph approximation with the peak rate occurring at the time of concentration and the end of the hydrograph at three (3) times the time of concentration may be used as an alternative.
System design.
1. Collection systems shall be designed to accommodate the intensity for a storm frequency of once in ten (10) years for storm drainage facilities located in or affecting streets of the rural, local and minor collector classifications. A storm frequency of once in twenty-five (25) years shall be utilized for systems affecting secondary arterial and major collector streets as well as all open channels.
2. Hydraulic capacity for open channel or closed conduit flow shall be determined by the Manning equation or charts/nomographs based on the Manning equation. The hydraulic capacity is termed "Q" and is expressed as discharge in cubic feet per second. The Manning equation is as follows:
Qp = (1.486 AR2/3 s1/2) / n
Where
n = Manning's roughness coefficient.*
A.= Cross-sectional area of flow in square feet.
R= Hydraulic radius in feet (R = Q/P, where P is equal to the wetted perimeter).
S= Slope of conduit in feet per foot.
NOTE: The Manning roughness coefficients to be utilized are shown in the Technical Manual for Stream Encroachment, NJDEP, Table 3.2-11(A-1).
3. Velocities in open channels at design flow shall not be less than five-tenths (0.5) foot per second and not greater than that velocity which will begin to cause erosion or scouring of the channel. Permissible velocities for swales, open channels and ditches are allowed for the appropriate soil type based on the Soil Conservation Service Standards for Soil Erosion and Sediment Control in New Jersey, as amended.
4. Velocities in closed conduits at design flow shall be at least two (2) feet per second but not more than ten (10) feet per second.
5. No pipe size in the storm drainage system shall be less than fifteen (15) inches in diameter.
6. All discharge pipes shall terminate with a precast concrete flared end section or a cast-in-place concrete headwall with or without wingwalls as conditions dictate.
7. The spacing of inlets shall be such that surface water shall not flow for more than five hundred (500) feet or the quantity of water is such that it caused ponding of water deeper than two (2) inches at Type B and Type E inlets, whichever is the lesser distance. If due to the slope of the approach prior to the inlet, eighty percent (80%) of the stormwater does not enter the inlet, decreased spacing and depth of water permissible shall be required. Sufficient inlets will be placed to eliminate any flow exceeding two (2) cubic feet per second across any roadway intersections or pedestrian crosswalk.
8. Dished gutters shall be permitted at any street intersection on rural and local streets and at the intersection of rural and local streets with minor collector streets and at the intersection of minor collector streets with major collector streets where the street of the lower classification is to be officially designated and signed as a stop street. In such case, the dished gutter shall cross only the street of the lower classification. At the intersections of primary and secondary arterial streets and major collector streets, sufficient catch basins, at the discretion of the reviewing agency, shall be installed at each street intersection to avoid gutter overflow and at low points in the street grade, and dished gutters shall not be permitted.
9.Manhole spacing shall increase with pipe size. The maximum spacing shall be five hundred (500) feet for fifteen (15) to eighteen (18) inches; six hundred (600) feet for twenty-one (21) to thirty-six (36) inches; and seven hundred (700) feet for forty-two (42) inches and greater.
Construction Standards for Pipe.
1. Materials used in the construction of storm sewers shall be constructed of reinforced concrete, ductile iron, corrugated aluminum or corrugated steel unless site and other conditions dictate otherwise. Reinforced concrete pipe shall be used unless the applicant can demonstrate that the use of other materials will be more beneficial due to the proposed installation. Cost will not be a consideration in this analysis. Specifications referred to, such as American Standards Association, American Society for Testing and Materials, American Water Works Association, etc., should be the latest revision.
2. Reinforced Concrete Pipe.
a. Circular reinforced concrete pipe and fittings shall meet the requirements of ASTM C-76.
b. Elliptical reinforced concrete pipe shall meet the requirements of ASTM C-507.
c. Joint design and joint material for circular pipe shall conform to ASTM C-443.
d. Joints for elliptical pipe shall be bell and spigot or tongue and groove, sealed with butyl, rubber tape or external sealing bands conforming to ASTM C-877.
e. All pipe shall be Class III unless a stronger pipe (i.e., higher class) is indicated to be necessary.
f. The minimum depth of cover over the concrete pipe shall be as designated by the American Concrete Pipe Association.
3. Ductile Iron Pipe. Ductile iron pipe shall be centrifugally cast in metal or sand-lined molds to ANSI A 21.51-1976 (AWWA C151-76). The joints shall conform to AWWA C111. Pipe shall be furnished with flanges where connections to flange fittings are required. Pipe should be Class 50 (minimum). The outside of the pipe should be coated with a uniform thickness of hot-applied coal tar coating and the inside line cement in accordance with AWWA C104. Ductile iron pipe shall be installed with Class C ordinary bedding.
4. Corrugated Aluminum Pipe. Within the public right of way and where severe topographic conditions or the desire to minimize the destruction of trees and vegetation exist, corrugated aluminum pipe, pipe arch or helical corrugated pipe may be used. The material shall comply with the Standard Specifications for Corrugated Aluminum Alloy Culvert and Under Drain AASHTO destination M196 or the Standard Specification for Aluminum Alloy Helical Pipe AASHTO Designation M-211. The minimum thickness of the aluminum pipe to be used shall be:
g. Less than twenty-four-inch diameter or equivalent, seventy-five thousandths (0.075) inch (14gauge).
h. Twenty-four-inch diameter and less than forty-eight-inch diameter or equivalent, one hundred five thousandths (0.105) inch (12-gauge).
i. Forty-eight-inch but less than seventy-two-inch diameter or equivalent, one hundred thirty-five thousandths (0.135) inch (10-gauge).
j. Seventy-two-inch diameter or equivalent and larger, one hundred sixty-forty thousandths (0.164) inch (8-gauge).
5. Corrugated Steel Pipe. Corrugated steel pipe may be used in place of corrugated aluminum and shall meet the requirements of AASHTO Specification M36. Coupling bands and special sections shall also conform to AASHTO M-36. All corrugated steel pipe shall be bituminous coated in accordance with AASHTO M-190 Type A minimum.
6. Pipe bedding shall be provided as specified in Design and Construction of Sanitary and Storm Sewers, ASCE Manuals and Reports on Engineering Practice Number 37, prepared by A Joint Committee of the Society of Civil Engineers and the Water Pollution Control Federation, New York, 1969.
Construction standards for inlets, catch basins and manholes. Inlets, catch basins and manholes shall be designed in accordance with State Highway Department Standard Plans and Specifications. Frames shall be Campbell Foundry Company Pattern Number 2541, 2548, with eight-inch curb face, and 3432, 3440, for Type E inlets, or approved equal. All grates shall be bicycle grates.
1. Manholes and catch basins shall be precast concrete, brick or concrete block, coated with two (2) coats of portland cement mortar.
2. If precast manhole barrels and cones are used, they shall conform to ASTM Specification C-473 with round rubber gasketed joints, conforming to ASTM Specification C-923. Maximum absorption shall be eight percent (8%) in accordance with ASTM Specification C-478, Method A.
3. If precast manholes are utilized, the top riser section shall terminate less than one (1) foot below the finished grade and the manhole cover shall be flush with the finished grade.
4. Manhole frames and covers shall be of cast iron conforming to ASTM Specification A-48 Class 30 and be suitable for H-20 loading capacity. All manhole covers in rights-of-way or in remote areas shall be provided with a locking device. The letters "Year 20 " and the words "STORM SEWER" shall be cast integrally in the cover.
Detention Facilities.
1. Development shall use the best available technology to accommodate stormwater management by natural drainage strategies as indicated in section D of this section.
2. Detention and all other stormwater management facilities shall conform to the standards under the New Jersey Stormwater Management Act, N.J.S.A. 40:55D-93 et seq.
3. Where detention facilities are deemed necessary, they shall accommodate site runoff generated from two-year, ten-year and one-hundred-year storms considered individually, unless the detention basin is classified as a dam, in which case the facility must also comply with the Dam Safety Standards, N.J.A.C. 7:20. These "design storms" shall be defined as either a twenty-four-hour storm using the rainfall distribution recommended by the United States Soil Conservation Service (such as United States Soil Conservation Service, Urban Hydrology for Small Watersheds, Technical Release Number 55) or as the estimated maximum rainfall for the estimated time of concentration of runoff at the site when using a design method such as the modified rational method. Runoff greater than that occurring from the one-hundred-year, twenty-four-hour storm will be passed over an emergency spillway.
Detention will be provided such that, after development, the peak rate of flow from the site will not exceed that by similar storms prior to development.
4. In calculating the site runoff to be accommodated by a detention facility, the method to be used is a tabular hydrograph method as presented in TR Number 55 (SCS method), as supplemented and amended. The pre-developed lands in the site shall be assumed to be in good condition, if the lands are woods, or with conservation treatment, if the land is cultivated, regardless of conditions existing at the time of concentration.
5.Detention facilities shall be located as far horizontally from surface water and as far vertically from groundwater as is practicable. A complete soils report for the detention basins and surrounding areas shall be submitted. The report should address the effect groundwater will have on the construction and maintenance of the detention basins.
6. Only one-half (1/2) of the area devoted to detention or retention facilities shall be considered nonimpervious surfaces in calculating the maximum percentages as set forth in other sections of this chapter. The area devoted shall be the area encompassed by the depth of water to the emergency spillway, plus one (1) foot.
7. The top of the excavation or the toe of the outside slope shall be set back twenty-five (25) feet from adjoining nonresidential property lines and fifty (50) feet from an adjoining property line of a lot on which there is a residential use. The edge of the design high water for the detention basins shall be setback one hundred (100) feet existing or proposed dwelling units.
8. The top of the excavation or the toe of the outside slope shall be set back fifty (50) feet from the edge of the pavement from adjoining roads and shall be set back twenty-five (25) feet from the adjoining right of way line for any right of way dedicated for use as a public road.
9. Dry detention basins. The following design standards shall apply to all dry detention basins:
a. The maximum embankment side slopes shall have the ratio of one (1) vertical to three (3) horizontal.
b. Basin bottom shall meet the following specifications:
(1) Traverse slope (to low flow channel); minimum two percent (2%);
(2) Low flow channel if sodded: minimum slope two percent (2%);
(3) Low flow channel if concrete; slope not less than one percent (1%);
(4) Riprap low flow channel will not be accepted.
c. An area ten (10) feet wide with a maximum slope of two percent (2%) shall be constructed at the top of the bank surrounding the basin.
d. Vegetation stabilization cover shall be provided throughout the basin and landscaping shall be provided on the perimeter of the basin as approved by the Board's landscape architect.
e. The basin floor shall lie a minimum of two (2) feet above the seasonal high groundwater table.
10. Wet detention/retention basins are discouraged. Wet basins may be permitted only if no other above ground stormwater management facility is feasible.
11. Underground detention/retention basins are discouraged. Underground detention/retention basins may be permitted only if no other above ground stormwater management facility is feasible.
Protecting Water Quality
1. In addition to addressing water quantity generated by development, a stormwater management system shall also enhance the water quality of stormwater runoff.
2. In order to enhance water quality of stormwater runoff, stormwater management shall provide for the control of a water quality design storm. The water quality design storm shall be defined as the one-year frequency SCS Type III twenty-four-hour storm or a one-and-twenty-five-hundredths-inch two-hour rainfall.
3.The water quality design storm shall be controlled by best management practices. These include but are not limited to the following:
a. In dry detention basins, provisions shall be made to ensure that the runoff from the water quality design storm is retained such that not more than ninety percent (90%) will be evacuated prior to thirty-six (36) hours for all nonresidential projects or eighteen (18) hours for all residential project. The retention time shall be considered a brim-draw-down storage. The retention time shall be reduced in any case which would require an outlet size diameter of three (3) inches or less. Therefore, three-inch diameter orifices shall be the minimum allowed. The depth of the water quality storm should not exceed two (2) feet in depth.
b. In permanent ponds or wet basins, the water quality requirements of this section shall be satisfied where the volume of permanent water is at least three (3) times the volume of runoff produced by the water quality design storm.
Principal Outlets Quantity Control.
1. All principal outlet structures shall be concrete block or reinforced concrete. All construction joints are to be watertight. The outlet structure can consist of a riser, culvert pipe and/or weir outlet and must be accessible from the buffer area/access road when the basin is operational at full design flow for the 100-year design storm event.
To minimize the chance of clogging and to facilitate cleaning, outlet openings, other than 3a above, shall be at least six (6) inches in diameter. Similarly, riser pipes, if utilized, shall be at least eight (8) inches in diameter. All pipe joints are to be watertight, reinforced concrete pipe. In addition, trash racks and/or antivortex devices may be required where deemed necessary by the City. Outlet control structures should be protected by maintenance free trash racks. Trash racks should be designed to be on an incline with a clear opening area large enough so that debris buildup does not impede the area of the opening it protects. The trash rack should be a hinged rack and should avoid moving parts. It should be able to be opened to gain access for cleaning the outlet pipe, and should be made of a non-corrosive material (stainless steel or aluminum).
2. Eight-inch-thick antiseep collars are to be installed along outlet pipes. Such collars shall be constructed of reinforced concrete with minimum Number 5 bars, each way, and two (2) inches of cover.
3. Where applicable, a concrete cradle shall be provided for outlet pipes.
4. Suitable lining shall be placed upstream and downstream of principal outlets as necessary to prevent scour and erosion. Such lining shall conform to the criteria contained in Standards for Soil Erosion and Sediment Control in New Jersey, published by the New Jersey State Soil Conservation Committee.
5.All outlet facilities shall be designed to prevent the potential hazard of a child's or an adult's either being carried into the opening or being held against the outlet by the pressure of the flowing stream waters, even during a one-hundred-year storm.
6. Safe outlet structure design can encompass either outlet risers, gratings, trash racks or other means that, in the opinion of the Planning or Zoning Board, provide the desired level of safety.
7. Outlet structures should be designed to facilitate outlet operation and maintenance as the water level rises and to permit clearing either during or after a storm. Structural support members, steps, rungs or ladders should be provided to allow easy escape opportunities for a child or an adult without having these support members, ladders, etc., impede the clearing of trash from the outlet structure or the upward movement of trash from the outlet structure or the upward movement of trash as the water level rises.
8. The use of thin metal plates for trash rack bars, hand hold supports, sharp crested weirs or orifices are prohibited because of the potential for accidents. Wire mesh fabric is similarly prohibited due to its poor suitability for trash clearance.
9. Any outlet protective facility should have lockable hinged connections providing adequate access to thoroughly clean the area enclosed by the structure and to facilitate removal of accumulated debris and sediment around the outlet structure.
10. The outlet protective structure should have negligible influence upon the hydraulic performance of the outlet structure.
11. All outlet structures shall be structurally sound and shall be designed to withstand, without failure or permanent deformation, all structural loads, hydrostatic, dynamic or otherwise, which impact upon it during the design life of the installation. They shall be maintenance free to the maximum extent possible.
12. The detention/retention basin side slope walls shall be graded to slopes no greater than three (3) horizontal to one (1) vertical for a distance no less than twenty-five (25) feet on all sides of the outlet structure.
13. Other means of attaining the same outlet safety condition, such as inaccessible outlet locations, weirs, cascades, etc., will be considered as approvable if the same goals were attained.
14.Existing basins and outlet structures shall be revised by the respective responsible owners to comply with the above-defined goals within one (1) year of the enactment of this amendment.
Principal Outlets Quality Control.
1. Based upon the requirement limiting the size of the outlet to a minimum of six (6) inches in diameter, water quality control shall be maintained by providing an amount of storage equal to the total amount of runoff which will be produced by the one-year frequency SCS Type III twenty-four-hour storm or a one-and-twenty-five-hundredths-inch, two-hour rainfall at the bottom of the proposed detention basin along with a minimum three-inch diameter outlet.
2. The invert(s) of the principal outlet(s) used to control the larger storms for flood control purposes should be set at the elevation of the water surface elevation required to produce the water quality storage volume. Therefore, the principal outlets would be utilized for storms in excess of the one-and-twenty-five-hundredths-inch, two-hour event which, in turn, would be completely controlled by the lower three-inch outlet. If the above requirements would result in a pipe smaller than three (3) inches in diameter, the period of retention shall be waived so that three (3) inches will be the minimum pipe size used. It should be remembered that, in all cases, the basin should be considered initially empty (i.e., the storage provided for the quality requirements and the discharge capacity of its outlet should be utilized during the routing of the larger flood control storms).
Emergency Spillways.
1. Vegetated emergency spillways shall have side slopes not exceeding three (3) horizontal to one (1) vertical.
2. Emergency spillways not excavated from noncompacted soil shall be suitably lined and shall comply with criteria contained in Standards for Soil Erosion and Sediment Control.
3.Maximum velocities in emergency spillways shall be checked based on the velocity of the peak flow in the spillway resulting from the routed emergency spillway hydrograph. Where maximum velocities exceed those contained in Standards for Soil Erosion and Sediment Control in New Jersey, suitable lining shall be provided.
Dams and Embankments.
1. The minimum top widths of all dams and embankments are listed below. These values have been adopted from the Standards for Soil and Sediment Control in New Jersey, published by the New Jersey State Soil Conservation Committee.
MINIMUM TOP WIDTHS FOR DAMS & EMBANKMENTS
2. The design top elevation of all dams and embankments after all settlement has taken place shall be equal to or greater than the maximum water surface elevation in the basin resulting from the routed freeboard hydrograph. Therefore, the design height of the dam or embankment, defined as the vertical distance from the top down to the bottom of the deepest cut, shall be increased by the amount needed to ensure the design top elevation will be maintained following all settlement. This increase shall not be less than five percent (5%). Where necessary, the Engineer shall require consolidation tests of the undisturbed foundation soil to more accurately determine the necessary increase.
3. Maximum side slopes for all dams and embankments are three (3) horizontal to one (1) vertical.
4. All earth fill shall be free from brush, roots and other organic material subject to decomposition.
5. Cutoff trenches are to be excavated along the dam or embankment centerline to impervious subsoil or bedrock.
6. Safety ledges shall be constructed on the side slopes of all detention basins having a permanent pool of water. The ledges shall be four (4) to six (6) feet in width and located approximately two and one-half (2 1/2) to three (3) feet below and one (1) to one and one-half (1 1/2) feet above the permanent water surface.
7. The fill material in all earth dams and embankments shall be compacted to at least ninety-five percent (95%) of the maximum density obtained from compaction tests performed by the appropriate method in ASTM D698.
8. The top of bank for facilities constructed in cut and the toe of slope for facilities constructed in fill shall be located no closer than ten (10) feet to an existing or proposed property line.
9.Detention basins shall be sodded, attractively buffered and landscaped and designed as to minimize propagation of insects, particularly mosquitoes. All landscaping and buffering shall be approved by the City.
Detention Facilities in Flood Hazard Areas.
There will be no detention basins in the floodway except for those on-stream and shall comply with all applicable regulations under the Flood Hazard Control Act, N.J.S.A. 58:16A-50 et seq., and the New Jersey Stormwater Management Act, N.J.S.A. 40:55D-93 et seq.
Detention facilities in freshwater wetlands.
Detention basins located in freshwater wetlands may be allowed only in accordance with the Freshwater Wetlands Protection Act, N.J.S.A. 13:9B-1 et seq. and any rules adopted pursuant thereto.
Detention Facilities; Maintenance and Repair.
1. Responsibility for operation and maintenance of detention facilities, including periodic removal and disposal of accumulated particulate material and debris, shall remain with the owner or owners of the property with permanent arrangements that it shall pass to any successive owner, unless assumed by a government agency. 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 maintenance, hereinafter in this section referred to as the "responsible person."
2. Prior to granting final approval to any project subject to review under this section, the applicant shall enter into an agreement with the municipality (or county) to ensure the continued operation and maintenance of the detention facility. This agreement shall be in a form satisfactory to Corporation Counsel and may include, but may not necessarily be limited to, personal guaranties, deed restrictions, covenants and bonds. In cases where property is subdivided and sold separately, a home-owners' association or similar permanent entity should be established as the responsible entity, absent an agreement by a governmental agency to assume responsibility.
a. An applicant seeking approval for construction of a detention facility shall provide the funds necessary to permanently maintain the facility. The amount necessary to permanently maintain the facility shall be calculated by the Planning Board Engineer based upon current estimates for maintenance with an annual increase of four percent (4%). The Planning Board Engineer shall also assume that the investment will yield a return equal to the ninety-day certificate-of-deposit interest rate paid by the city fiduciary institution or its successor on the date the calculation is made.
b. The form of security for the maintenance of the facility shall be approved by Corporation Counsel.
3.In the event that the detention facility becomes a danger to public safety or public health or if it is in need of maintenance, the municipality shall so notify in writing the responsible person. From that notice, the responsible person shall have fourteen (14) days to effect such maintenance and repair of the facility in a manner that is approved by the City Engineer or his designee. If the responsible person fails or refuses to perform such maintenance and repair, the municipality may proceed to do so and shall bid the cost thereof to the responsible person.
Division of Coastal Resources.
1. All projects containing stream encroachments within the flood hazard area and one-hundred-year floodplain, at locations having a drainage area of over fifty (50) acres and all projects of special concern, as defined in N.J.A.C. 7:13-5, are subject to the approval of NJDEP, Division of Coastal Resources.
2. All projects containing a drainage area over fifty (50) acres must establish the one-hundred-year floodplain zone in accordance with N.J.A.C. 7:13-1.8.
The approval of any map of land delineating streets by the Planning Board of the City of Plainfield shall be in no way construed as an acceptance of any street indicated thereon.
For both major and minor subdivisions, blocks and lots shall be graded to secure proper drainage away from buildings and t prevent the collection of stormwater in pools.
For both major and minor subdivisions, land subject to periodic or occasional flooding (floodplain areas) shall not be plotted for residential occupancy nor for any other purpose which may endanger life or property or aggravate the flood hazard. Such land within a plat shall be considered for open spaces or other similar uses.
Where a minor or major subdivision is traversed by a watercourse, surface or underground drainage way or drainage system, channel or stream, there shall be provided and dedicated a drainage right of way easement to the City conforming substantially with the lines of such watercourse and of such further width or construction, or both, as will be adequate to accommodate expected stormwater runoff, fifteen (15) feet beyond the bank top on at least one (1) side for access to the drainage right of way and, in any event, meeting any minimum widths and locations shown on the adopted Official Map or Master Plan. Such easement dedication shall be expressed on the plat as follows: "Drainage and utility right of way easement granted to the City of Plainfield." No relocation, construction or reconstruction shall take place within the area of the easement, nor shall any structures be located within such area, nor shall any action be taken which may alter or impair the effectiveness of present or future drainage facilities or cause soil erosion without prior approving authority or City Council approval.
Prohibitions on the discharge of storm drainage and groundwater.
1. Stormwater, groundwater, rainwater, street drainage, subsurface drainage or yard drainage shall not be discharged through direct or indirect connections of a sump pump, cellar drain or any other means of conveyance into a community sanitary sewer owned or operated by the Plainfield Municipal Utility Authority (PMUA) or any sewerage authority.
2. Any person who is convicted of violating any provision of this section shall be fined not less than fifty dollars ($50.) for a first offense and not less than one hundred dollars ($100.) for each subsequent offense.
