Disclaimer. This model ordinance is an example of an approach. It should be modified to reflect local environmental conditions, current regulations, and state-of-the-art knowledge in the environmental field.

1. STATUTORY AUTHORITY

The Municipal Land Use Law, N.J.S.A. 40:44D-1 et seq. and the Soil Erosion and Sediment Control Act, N.J.S.A. 4:24-39 et seq., provide the statutory authority for this ordinance.

2. FINDINGS OF FACT

It is hereby determined that:

A. Waterbodies, roadways, structures and other property within the municipality are at times subjected to flooding.
B. 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.
C. 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 and pollutant transport and deposition.
D. Land development projects and activities result in the construction of impervious surfaces, such as roads and parking lots, from which stormwater runoff flushes particulate and dissolved contaminants into streams and wetlands.
E. Stormwater runoff, soil erosion, stream channel erosion and nonpoint source pollution resulting from land development activities within the municipality have resulted in a deterioration of the water resources of the municipality.
F. Soil erosion, stream channel erosion and nonpoint source pollution can be controlled and minimized by the regulation of stormwater runoff from land development projects and activities.
G. The State of New Jersey's Surface Water Quality Standards (N.J.A.C. 7:9B-1.1 et seq.) 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 New Jersey municipalities for the regulation of stormwater runoff for purposes of protecting surface water resources from degradation.
H. Impervious surfaces and regraded earth surfaces associated with land development reduce the infiltration of rainfall and the recharge of groundwater resources.
It is therefore determined that it is in the public interest to regulate stormwater runoff from land development projects and other construction activities within (insert municipal name) as provided in this ordinance in order to control and minimize increases in stormwater runoff rates and volumes, to control and minimize soil erosion, stream channel erosion, and nonpoint source pollution associated with stormwater runoff and to provide for the recharge of groundwater resources.

3. PURPOSE

It is the purpose of this ordinance to establish standards and regulations for the management and discharge of stormwater runoff from land development projects and other construction activities:

A. To reduce artificially induced flood damage to public health, life, and property;
B. To minimize increased stormwater runoff rates and volumes;
C. To minimize the deterioration of existing water courses, culverts, bridges, dams and other structures that would result from increased rates of stormwater runoff;
D. To induce water recharge into the ground wherever suitable infiltration, soil permeability, and favorable geological conditions exist;
E. To prevent an increase in nonpoint source pollution;
F. To maintain the integrity and stability of stream channels for their biological functions, as well as for drainage, the conveyance of floodwater, and other purposes;
G. To control and minimize soil erosion and the transport of sediment;
H. To reduce stormwater runoff rates and volumes, and nonpoint source pollution;
I. To minimize public safety hazards at any stormwater detention facility constructed pursuant to subdivision or site plan approval;
J. To maintain high water quality in all streams and other surface water bodies;
K. To protect all surface water resources from degradation; and
L. To protect groundwater resources from degradation.

4. APPLICABILITY

This ordinance shall be applicable to any major subdivision or site plan application, as defined in the Municipal Land Use Law, located within the municipality, which involves disturbances of 1,000 square feet or more. Provisions of this ordinance pertaining to runoff from roof areas and requirements for drywells shall also apply to all applications for building permits except as otherwise provided for herein (Policy decision). The ordinance shall be applied to achieve its purposes to the extent reasonable and practical with respect to modifications of previously developed sites consistent with the nature and extent of such modifications.

7. DEFINITIONS
Unless specifically defined below, or in the Municipal Land Use Law (N.J.S.A. 40:55D-1 et seq.), or in the Soil Erosion and Sediment Control Act (N.J.S.A. 4:24-39 et seq.), or in New Jersey's Surface Water Quality Standards (N.J.A.C. 7:9B-1.1 et seq.), words or phrases used in this ordinance shall be interpreted so as to give them the meaning they have in common usage.
(Municipalities should include the following definitions in their adopted ordinance unless the definition is already provided for in the adopted subdivision and land development ordinance)
Agricultural development - land uses normally associated with the production of food, fiber, and/or 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.
Constructed wetland - a man-made freshwater wetland, designed and constructed for a specific purpose.
Detention basin - an impoundment area created by constructing an embankment, excavating a pit, or both, for the purpose of temporarily storing stormwater.
Detention facility - a detention basin or alternative structure designed to store stormwater runoff.
Floodplain - the area inundated by NJDEP's regulatory flood including the watercourse that creates it. NJDEP's regulatory flood means NJDEP's adopted Flood Hazard Area Design Flood along streams for which NJDEP has an adopted flood hazard area and floodway study, and the 100-year flood along non-delineated streams for which NJDEP has not delineated a flood hazard area.
Floodway - 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 regulatory flood. 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 NJDEP-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 - 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 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 shall be used.
Infiltration facility - 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.
NJDEP - the New Jersey Department of Environmental Protection.
Nonpoint source pollution - 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 - the replenishment of underground water reserves.
Regulatory flood - the 100-year flood along non-delineated watercourses or the Flood Hazard Area design flood along delineated watercourses.
Retention Basin - an impoundment area with a permanent pool made by constructing an embankment, or excavating a pit, or both, for the purpose of temporarily storing stormwater. A retention basin is also called a "wet basin" or "wet detention basin".
Somerset County Stormwater Detention Basin Handbook - the Handbook for Stormwater Detention Basins (with supplement) dated December 1991, published by the County of Somerset, New Jersey, and any subsequent revisions or amendments thereto.
Stormwater runoff - flow on the surface of the ground, resulting from precipitation.
S.C.S. - the Soil Conservation Service (now the Natural Resources Conservation Service) of the U.S. Department of Agriculture.
Treatment train - 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 satisfy the performance requirements associated with the no net increase provisions of this ordinance.
Water Quality Storm - a one-year frequency, 24-hour storm (2.7 inches of rainfall), using the Type III rainfall distribution recommended for New Jersey by the U.S. Soil Conservation Service or a storm of 1.25 inches of rainfall falling uniformly in two hours.

8. TECHNICAL STANDARDS

A. No Net Increase Goals
1. No net increase in nonpoint source pollution - Stormwater control systems shall be designed to prevent the degradation of water quality in receiving watercourses from nonpoint source pollution associated with stormwater runoff. NJDEP's Surface Water Quality Standards, NJAC 7:9B, shall be used 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) from stormwater runoff for storm events with magnitudes as high as the Water Quality 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 postdevelopment stormwater runoff rates from the site and at any point in the watershed between the site 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 - Wherever suitable infiltration, soil permeability, and favorable geological conditions exist, stormwater control systems shall be designed so that all stormwater runoff from impervious surfaces is infiltrated into the soil for the 1.25 inch, 2-hour storm.

B. Procedures for Measuring Compliance with the No Net Increase Goals 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-, 25-, 50- and 100-year storms.
a. The hydrologic and hydraulic analyses shall generally conform with methods developed by the Natural Resources Conservation Service and published in National Engineering Handbook, Section 4 - Hydrology, Technical Release No. 55 and Technical Release No. 20.
b. Standards and procedures for developing hydrographs and calculating peak rates of runoff shall be as shown in the Somerset County Stormwater Detention Basin Handbook.
c. Rainfall - Frequency relationships shall be as shown in Technical Paper No. 40, "Rainfall Frequency Atlas of the United States" published by the U.S. Weather Bureau.
2. For infiltration facilities proposed to meet the no net increase goals of this ordinance, the results of a subsurface investigation and soil tests demonstrating the suitability of the area's soils and groundwater table for infiltration and treatment of runoff shall be provided.
3. A nonpoint source pollutant loading analysis shall be prepared and submitted, demonstrating that the nonpoint source pollutant and sediment loadings resulting from the proposed land development or construction project do not exceed the standards set forth in this ordinance.
4. 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 December 1994, and any subsequent revisions thereto, prepared by the N.J.D.E.P. and the New Jersey Department of Agriculture.

C. Waivers From Strict Compliance
If the natural or existing physical characteristics of the project site preclude achievement of any of the above no net increase goals, the municipality may grant a waiver from strict compliance with the specific no net increase provisions the achievement of which are precluded, provided that the applicant demonstrates to the satisfaction of the municipal engineer that the adjacent waterways will not be impacted by the:
1. Deterioration or damage of existing culverts, bridges, dams, and other structures;
2. Deterioration of their biological functions, drainage, flood water conveyance, and other purposes;
3. Streambank or streambed erosion or siltation;
4. Increased flooding endangering public health, life and property.
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. However, those no net provisions that are not precluded by the site's physical characteristics shall be met.
If one or more of the "no net increase" goals of this ordinance cannot be met on site, the applicant shall provide off-site mitigation subject to the approval of the Planning Board/Zoning Board prior to project commencement. Options for mitigation are as follows:
5. The acquisition of privately owned lands, preferably adjacent to state open waters, located in the municipality can be dedicated for preservation or reforestation, in equivalent size to off-set the increase in volume of the Water Quality Storm from the proposed development site.
6. Mitigation can be performed on previously developed properties, public or private, within the municipality and preferably within the same drainage basin that currently lack stormwater management facilities designed and constructed in accordance with the purposes and standards of this ordinance. If infiltration is not feasible on the subject site, a construction cost estimate of a suitable infiltration system sized for the proposed development based on the assumption that average permeability had existed on the subject property shall be prepared and submitted by the applicant's professional engineer. Upon certification by the municipal engineer that the proposed design and estimate are reasonable, the amount so determined will be the amount required to provide other mitigation measures on previously developed or undeveloped properties.
7. Stormwater-related studies or regional stormwater management plans can be funded or specific projects recommended by the Ten Towns Great Swamp Watershed Management Committee can be implemented to the extent of the funds estimated under the procedure described in paragraph 2 above. This requirement shall be applied equally to all applications for development and redevelopment within the municipality. Increased stormwater runoff shall be calculated by the applicant's engineer and approved by the municipal engineer utilizing accepted engineering practices.

D. Design Standards for Detention and Retention Basins and Other Stormwater Management Measures
Design standards for detention and retention basins and other stormwater management measures are contained in the Stormwater Management Manual, dated (insert date) and any subsequent updates or revisions thereto, prepared by the Ten Towns Great Swamp Watershed Management Committee. These design standards shall be used for the design of detention and retention basins and all other stormwater management measures.

E. 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 sections 6F and 6G 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 shall 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 pollutant loadings, stormwater management facilities shall provide for the control of stormwater runoff in accordance with the following basic principles:
1. Infiltration should be implemented 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 New Jersey by the U.S. Soil Conservation Service or the Somerset County 24-Hour Design Storm Distribution.
2. Runoff shall be managed at the source whenever possible.
3. Water quality and infiltration device treatment trains shall be designed that utilize the natural qualities of the landscape.
4. Detention/retention basins are generally not suitable as infiltration facilities.
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, prepared by the New Jersey Department of Environmental Protection and the New Jersey Department of Agriculture, as from time to time revised or amended.
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 December 1994, prepared by the New Jersey Department of Environmental Protection and the New Jersey Department of Agriculture as from time to time revised or amended.

F. Dry Well Requirements for Roof Runoff and Runoff from Paved Recreation Courts
Wherever suitable infiltration, soil permeability, and favorable geological conditions exist, runoff from roof areas and paved recreation courts, such as tennis and basketball courts, and impervious patios shall be transported to dry wells for recharge of groundwater resources. Standards for the design of dry wells are contained in the Stormwater Management Manual, dated (insert date) and subsequent updates and revisions thereto, prepared by The Ten Towns Great Swamp Watershed Management Committee. These design standards shall be used for the design of dry wells.

G. Planning and Design Standards for Maintenance and Repair
A 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 shall 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. Standards for maintenance and repair are contained in the Stormwater Management Manual, dated (insert date) and subsequent updates and revisions, prepared by The Ten Towns Great Swamp Watershed Management Committee. These standards shall be followed for the maintenance and repair of all stormwater management measures.

H. 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, staff gauges indicating depth at lowest point, and outlet structures designed to limit access. Standard safety measures for stormwater management facilities are contained in the Stormwater Management Manual, dated (insert date) and subsequent updates and revisions prepared by the Ten Towns Great Swamp Watershed Management Committee.

7. REQUIREMENTS FOR A STORMWATER MANAGEMENT PLAN

A. Submission of Stormwater Management Plan
1. Whenever an applicant seeks municipal approval of major subdivision or site plan subject to this ordinance, the applicant shall submit a Stormwater Management Plan as part of the application.
2. The applicant shall demonstrate that the project meets the standards set forth in this ordinance.

B. Stormwater Management Plan Approval
The applicant's Stormwater Management Plan shall be reviewed as a part of the subdivision or site plan review process. That Board shall consult the engineer retained by the Board to determine if all of the requirements have been satisfied and to determine if the project meets the standards set forth in this ordinance.

C. Required Contents of Stormwater Management Plan
The following information shall be required in a Stormwater Management Plan:
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, property lines, and all other significant natural and man made features. 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 manmade 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 written description of the proposed project shall be provided with particular emphasis on aspects of the project which relate to stormwater runoff quantity and pollutant loads, and changes to the stormwater drainage characteristics of the site compared to existing conditions. The project description should clearly describe all stormwater management practices, methods, and BMPs that will be used on the site to meet the goal of no net increase. The description should clearly indicate how the stormwater management plan will meet the goal of no net increase. Guidelines for calculating pre-development and post-development pollutant loads and pollutant removal efficiencies are contained in the Stormwater Management Manual, dated (insert date) and subsequent updates and revisions, prepared by the Ten Towns Great Swamp Watershed Management Committee. These guidelines should be used in the Stormwater Management Plan.
A map (or maps) shall be provided 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.
4. Stormwater Management Facilities Plan - The following information shall be provided and illustrated on a plan of the same scale as the topographic base map, and shall include:
a. Total area to 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 plan to control and dispose of surface water.
b. Details of all stormwater management facilities 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. A Drainage Area Map - A map showing the total drainage area and sub-drainage areas shall be provided. The map shall also show soil types and their boundaries as shown in the ______ County Soil Survey, or as may otherwise be determined by an on-site soil investigation.
6. Calculations
a. Comprehensive hydrologic, hydraulic and pollutant load data and design calculations for the pre-development and post-development conditions for the design storms as specified in this ordinance shall be provided.
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 pits shall depend upon what is needed to determine the suitability and distribution of soil types present at the location of the control measure.
7. Maintenance and Repair Plan
a. The planning and design of the stormwater management facilities shall comply with Section 3G, Planning and Design Standards for Maintenance and Repair.
b. Maintenance procedures shall be detailed and shall provide for 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. 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 include inspections to ensure proper performance of the facility between scheduled clean out.
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. Disposal site(s) shall be included in the Soil Erosion and Sediment Control Plan and shall be approved by the municipal engineer.
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.

8. OPERATION, MAINTENANCE, REPAIR AND SAFETY

A. Applicability
Projects subject to review as specified in Section D of this ordinance shall comply with the requirements of Sections 8B & 8C.
B. Responsibility for Operation, Maintenance, Repair, and Safety
1. Responsibility for operation, maintenance, repair, and safety of stormwater management facilities, including periodic removal and disposal of accumulated particulate material and debris, shall remain with the property owner and all successors in title unless assumed by a governmental agency. 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.
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 long-term/perpetual operation, maintenance, repair, and safety 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 any proposed new responsible entity has the capability to perform the required 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 a designee. If for reasons of safety there is need for immediate action, the responsible person shall act forthwith to remove the danger. If the responsible person fails or refuses to perform such maintenance and repair, the municipality may immediately proceed to do so and shall be reimbursed for the cost thereof by the responsible person or entity.
C. Maintenance and Repair Procedures
1. 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, 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, control of mosquitos and other insects, pond maintenance, and review of maintenance and inspection work to identify where the maintenance program could be more effective.
2. Repair 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, repairs shall be performed on an as-needed or emergency basis and include such procedures as structural repairs, mosquito control, removal of debris, sediment and trash which threaten discharge capacity, erosion repair, snow and ice removal, fence repair, and restoration of vegetation.

9. ENFORCEMENT; VIOLATIONS AND PENALTIES
A. Enforcement
This ordinance shall be enforced by the municipal engineer who is empowered to cause any stormwater management facility to be inspected and examined and to order the remedying of any condition found to exist in violation of any provision of this ordinance.
B. Violations and Penalties
Violations and penalties shall be as provided in Article (insert appropriate article of ordinance) of the (insert municipal name) Code.

10. 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 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 ordinance, rule or regulation, statute, or other provision of law. Where any provision of this ordinance imposes restrictions 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.

11. 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.

12. EFFECTIVE DATE
This ordinance shall take effect upon final passage by the municipality.