Planning as a Method to Control Nonpoint Source
Pollution
The Municipal Land Use Law ................................................................................... 2
The Master Plan ........................................................................................................ 2
The Open Space Plan ................................................................................................ 3
Zoning ....................................................................................................................... 4
Subdivision and Site Planning, Site Review, and Approval ..................................... 4
Environmentally Sensitive Development .................................................................. 5
Redevelopment and Restoration................................................................................ 10
Summary ................................................................................................................... 11
References ................................................................................................................. 11
Source: A Cleaner Whippany River Watershed - Nonpoint Source Pollution Control
Guidance Manual for Municipal Officials, Engineers, and DPW Personnel
New Jersey Department of Environmental Protection
Division of Watershed Management in collaboration with the Whippany Nonpoint Source Work
Group
May 2000
1
Chapter 3 Planning as a Method to Control Nonpoint Source Pollution
The Municipal Land Use Law
Many New Jersey communities with stormwater runoff problems find either that initial
planning failed to consider the environmental impacts of development or that sufficient thought was
not given to planning for such impacts. In these cases, towns are faced with the prospect of
implementing Best Management Practices (BMPs) after a given land use has been established. Such
"after the fact" BMPs installations have limited value because the BMPs often are unable to manage
effectively the significant levels of pollution that land development tends to generate. A second
limitation of such installations is that they often fail to account for the cumulative impacts of
individual land uses. Relying on "after the fact" installations may thus result iti a significant adverse
impact on water quality in the region. This need not be the case; because certain land use powers
assigned to each New Jersey municipality through the Municipal Land Use Law (MLUL) allow the
municipality to plan for controlling development-generated environmental impacts. These powers
occur in the form of master plans, zoning ordinances, and subdivision and site plan reviews.
If properly coordinated in the Whippany River watershed, master plans, zoning ordinances,
and subdivision and site plan reviews can reduce water pollution in two ways:
1) Zoning ordinances can control the rate of growth and the location and type of development in a
given community. Additionally, comprehensive plans that guide growth in ways that prevent or
minimize pollution can be adopted.
2) Pollution generated by a given level of growth can be reduced through land use, subdivision and
site plan ordinances, and special overlay districts.
When properly implemented, land use controls establish development patterns that are consistent
with regional water quality protection and other environmental objectives, while still providing for
economic development.
The Master Plan
Overall, land use is guided by the municipal master plan. Such a plan takes into account a
wide range of factors, including the protection of water quality and other environmental goals. The
master plan provides local governments and the public with the town's vision and policies for the
future as well as planning techniques for achieving community objectives.
In order to plan adequately and to conserve natural resources in the most effective manner
possible, the master plan should be based on the municipality's Environmental Resource Inventory
(ERI), which identifies the town's significant physical features, natural resources such as wetlands
and watercourses, geological characteristics, soils, and topography. This information is critical to
the master plan, which, according to the Municipal Land Use Law (MLUL), is "to guide the use of
lands within the municipality in a manner to protect public health and safety and promote general
welfare." The Environmental Resource Inventory identifies areas where development is appropriate
and areas where it should be avoided.
It also provides the planning board and zoning board of adjustment with information that
identifies environmentally sensitive areas such as trout streams, endangered species habitats, and
those areas of the municipality which, due to inherent characteristics, would generate a dispro-
2
portionate amount of stormwater runoff if disturbed. The steeply sloped regions of the western
Whippany River watershed are good examples of areas, which, if disturbed, generate such
stormwater runoff.
Safeguarding the natural features of a municipality can control stormwater while
simultaneously providing for the various needs of the community. For example, many
municipalities have located both passive (sitting areas/walking paths) and active (ballfields) parks
along stream corridors. These "natural regions" maintain vegetative buffer zones that control
erosion and attenuate pollutants before they reach the waterway. In addition, development located
outside of local floodplains can help prevent flood damage to residential, commercial, and industrial
properties.
The MLUL intends municipalities to address regional concerns by requiring that planning
boards indicate in their master plans the relationship of the municipality's proposed development
with neighboring municipalities, the county, and the State Development and Redevelopment Plan.
A municipal master plan should also be consistent with the water quality management plan or the
watershed management plan for its area. This means that the master plan and the wastewater
infrastructure needed to support the master plan should reflect the policies and the goals of the
water quality or watershed plan. If pollution is to be effectively controlled, the framework for all
land use design and allocation must be compatible with surrounding natural features, the carrying
capacity of the area, and development patterns in the region.
Its necessity in the local planning process and the fact that it provides the legal basis for
zoning and land use ordinances give the master plan an importance that cannot be overemphasized.
The Open Space Plan
Communities should develop a comprehensive municipal open space preservation plan.
Open space preservation is a sound municipal investment, both environmentally and economically.
Open space that is permanently protected using today's dollars pays off in both present and future
dividends of cleaner surface and ground water, cleaner air, better wildlife habitat, recreational
opportunities, improved aesthetics, increased property values, and freedom from the tax burden of
providing municipal services to developed properties.
The open space preservation plan should be made an integral part of the municipal master
plan. Natural features such as steep slopes, wetlands, riparian corridors, scenic vistas, and areas of
unique value should be targeted along with associated buffer areas. Consideration should be given
to interconnecting open space areas as much as feasible.
The 1999 Revised New Jersey Residential Site Improvement Standards (RSIS) administered
by the Department of Community Affairs "governs any site improvements carried out in connection
with any application for residential subdivision, site plan approval, or variance." Section 5:21-7.5b
states: "Design engineers shall coordinate structural detention requirements with nonstructural
practices, such as cluster and land use development, open space acquisition, riparian buffers..."
3
Table 3.1
ERI
↓
MASTER PLAN (including Open Space Plan)
↓
ZONING DESIGNATIONS
↓
ZONING ORDINANCE REQUIREMENTS FOR EACH ZONE
↓
LAND USE ORDINANCE REQUIREMENTS FOR ALL ZONES
Zoning
Zoning determines the density and location of different land uses within a municipality.
Zoning designations are intended to prevent incompatibility of neighboring uses and restrict uses
that are harmful to the health and well being of the community. In turn, zoning or land use
ordinances regulate development in those different zones. For example, different zones will have
different setback requirements. Subdivision and site plan requirements are part of zoning or land
ordinances. Zoning should consider the suitability and character of each district to support particular
uses and encourage the most appropriate land uses. Zoning can be an important tool for controlling
nonpoint source pollution by regulating development density, guiding building placement, and
restricting land uses to those that are compatible with protecting water quality in particular
locations.
Using the principles established in the master plan, a town could implement zoning
ordinances that place limitations on development in environmentally sensitive areas. Clustering,
impervious surface restrictions, setbacks, special. use permits, design and performance standards,
protection of critical areas like floodplains, and overlay districts are but some of the possible zoning
provisions that can be used to protect water quality. One example common in New Jersey is the use
of buffer zones around wetlands and streams.
Subdivision and Site Planning, Site Review, and Approval
The site plan and subdivision review process implements zoning. Review procedures should
incorporate specific criteria regarding site design. The review process allows development plans to
be evaluated according to the ordinances that establish standards for dealing with environmental
constraints of the site. It is the responsibility of the planning or zoning board to ascertain that a
proposed development is adequately designed for stormwater management prior to approval of a
site plan. For example, the board should determine, with the assistance of a qualified professional
engineer, that the rate and velocity of runoff from a site following completion of development
would not exceed that which would occur if the tract were not developed. In current practice this is
an easily solved engineering problem that usually results in the installation of a structural
stormwater control device. In reviewing proposed stormwater facilities, such as detention basins,
reviewers should question the type of maintenance required; who will maintain the structures; and
whether the structures have been sufficiently sized.
The New Jersey Standards for Soil Erosion and Sediment Control contain procedures and
practices required in New Jersey for the control of erosion from most construction sites. These
4
standards are administered by the New Jersey State Soil Conservation Committee, NJDA, through
the sixteen local Soil Conservation Districts. These standards are integral to the site planning
process.
However, subdivisions and site planning review for stormwater and nonpoint source
pollution should not be simply focused on the use of these structural devices, which are designed to
artificially regulate runoff rates and volumes. Other considerations related to water quality and
quantity discussed in subsequent sections of this manual also need to be taken into account. Many
of the steps suggested here have been incorporated into Whippany River Watershed Management
Plan. The completed watershed management plan should adequately address watershed
management program goals, site-specific program goals, existing conditions, watershed problems,
and contaminants of concern. The remaining tasks, which will be addressed in this volume, are
screening and selecting BMPs most appropriate for a specific watershed and implementing the
plan.
Environmentally Sensitive Development
Proper site planning can prevent increases in runoff, thereby reducing the potential for
erosion and sedimentation problems in new development. The following goals, which promote the
concept of "designing with nature," provide a good starting point for preventing increases in runoff
by guiding our choice of practices and strategies for site development toward those that reduce the
root causes of stormwater problems. These strategies also work for any site that is being
redeveloped.
Minimum Disturbance Ordinances
The philosophy of minimum disturbance suggests that the area of disturbance for a
development site include only the land required for the structure and any related utilities, drives,
and walks. Areas outside of the disturbance zone retain their natural vegetation. Assuming that land
use categories have been established through comprehensive land use plans and zoning ordinances,
vegetation mapping can be used to illustrate where proposed development can be constructed with
minimal impact on existing vegetation. As long as species tolerant of the local conditions are
planted in disturbed areas, the completed site will not require extensive ongoing fertilization or
applications of pesticides, although minimal maintenance and cutting may be appropriate. This
practice discourages, but does not preclude, establishment of lawn areas. Municipal ordinances can
be adopted which allow for limited lawn areas. For example, the Pinelands Comprehensive
Management Plan permits lawns planted with non-native grass species provided the lawns do not
exceed 2000 square feet per building.
As defined here, minimum disturbance for NPS control can be applied generally to a large
development proposal or to an individual lot. Essentially this approach would require minimal
disturbance or preservation of existing topography and native vegetation on large tracts of
undeveloped land.
This best management practice is clearly compatible with larger, area-wide planning
approaches, extending well beyond the limits of particular parcels or sites. For example, the
approach can and should supplement a natural drainage system protection plan, where actual
disturbance or construction would not be allowed within drainage ways and adjacent buffer zones.
In such a context, natural areas left intact, as the result of minimum disturbance would reinforce the
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natural functions of the drainage system. However, safety and/or water quality considerations might
dictate otherwise in certain situations.
As the parcel size diminishes, the successful application of this approach diminishes. In
addition, the use of this BMP becomes more problematic on small lots in heavily developed areas.
Clearly,' development sites exist. which do not lend themselves to the minimum disturbance
ideology. The exact dimensions of land disturbance are somewhat subjective and depend on factors
such as lot size and site specific conditions. For example, a single-family residential development
can be constructed with a narrower zone of disturbance, in relative terms, than a mall or office park
that may require larger construction equipment with greater maneuverability. Another example is a
housing development being constructed in a former agricultural field, where limiting the
disturbance of vegetation in this setting is not as great a concern. However, the careful selection of
plant material to use for landscaping a farm converted to a housing development is an effective
water quality BMP.
Hydrology
The linkage of minimum disturbance and hydrology can be addressed comprehensively at
the level of site planning (Schueler, 1987). In recent decades, the focus of stormwater management
has been on reducing the frequency and severity of flooding, chiefly by leveling peak discharges
from new development to pre-development levels. Concern for volume focused only on providing
adequate storage volume to hold a cap on peak discharge (e.g., detention ponds). Not enough
attention has been given to reducing or keeping volume constant, thereby providing more water
quality controls. Stormwater conveyance systems were specifically designed to increase hydraulic
efficiency through higher velocities and smooth conveyances (e.g., storm sewers, paved gutter and
waterways) so as to be self-cleaning. This approach implicitly accepted radical change from predevelopment hydrological conditions as a reasonable and unavoidable consequence of land
development. One possible result of such practice is a prolonged flood stage in streams, due to the
discharge of predevelopment peak flows from many sites over much longer periods.
One of the tenets of minimum disturbance development is to reproduce, as closely as
possible, pre-development hydrologic conditions, (i.e., peak discharge, runoff volume, infiltration
capacity, base flow levels, ground water recharge, and water quality). These issues revolve around
the amount of imperviousness allowed in development standards and its relationship to drainage
paths and vegetative cover. Simply limiting peak discharge is only a beginning to a narrowly
defined problem that is easily solved providing detention facilities.
Soil Quality
Maintaining predevelopment soil quality is very important when considering the
importance of maintaining infiltration and reducing runoff. Too often the disturbance and grading
associated with construction result in severely compacted soils. In addition, the soil's biological
activity is greatly diminished. Soils damaged by construction disturbance do not infiltrate rainfall
adequately, and they contribute considerably more runoff than preconstruction soils, particularly if
such soils were located in a wooded site.
While principles like minimum disturbance greatly help to reduce this problem, additional
BMPs can be used on disturbed sections of the site to remediate or prevent excessive degradation
of soil quality:
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Reduce soil compaction:




Use lightest weight machinery possible
Use track or wide-tire machinery
Avoid working in saturated soils
Follow the same wheel tracks through site whenever possible to limit areal extent of
compaction
 Perform subsoiling operation to break up compacted layers prior to the spreading of topsoil
Stimulate biological activity:




Add organic matter such as leaf compost to subsoil
Maintain pH around 7.0
Avoid excessive nitrogen and fertilization
Reduce pesticide use (Smith, 1997)
Development and Terrain
Another component of the minimum disturbance philosophy is to fit development to the
terrain. Road patterns should be chosen to provide access schemes that match landforms. For
instance, in rolling or dissected terrain, use strict street hierarchies with local streets branching from
collectors in short loops and cul-de-sacs along ridge lines. This approach results in a road pattern
that resembles the branched patterns of ridge lines and drainageways in the natural landscape,
facilitating the development of plans that work with the landform and minimize disruption of
existing grades and natural drainage.
In areas in the Whippany River watershed where the topography is characteristically flat, the
use of fluid grids may be appropriate. In this type of scheme, natural drainageways are preserved by
interrupting and bending the grid around them. Artificial grassed waterways may then be
constructed (at very flat slopes to maximize pollutant removal) at the back of lots or along the street
right-of-ways, so as to channel runoff to natural drainageways without abrupt changes of direction.
The best way to begin to achieve the above goals is to limit the area of disturbance. Clearing
and grubbing should only occur on those portions of the site where it is necessary for construction.
Ideally, disturbance should be limited to the locations of buildings, access ways, and utilities. The
proposed limits of land disturbance should be clearly marked in the field to ensure that only the
required land area is cleared.
Encourage compact development in environmentally sensitive ways
The best way to prevent the adverse impacts of development on runoff and water quality is
to develop comprehensive site plans that prevent construction activity in the most sensitive areas
(NISE & SCSC, 1981). Given the open space requirements found in most zoning codes, this
practice is a real option too often overlooked. Although regular, rectangular lots are readily
understood, ownership lines should be permitted to follow existing features on the site such as tree
lines or stone rows. Avoid siting improvements along the shoreline of lakes or streams, in natural
drainageways, or in areas of the site dominated by steep slopes, dense vegetation, or porous or
erodible soils. The following is a brief enumeration 'of the issues and site planning responses
associated with each of these sensitive areas:
1. Riparian Corridors
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Construction activity along riparian corridors is the most difficult to mitigate with respect
to water quality. Vegetated buffers are a critical part of nature's system for cleansing runoff water of
pollutants. Once the vegetation is disturbed, bank erosion is dramatically increased. Runoff from
construction so close to the receiving waters is hard to control, making measures to reduce pollutant
delivery much more difficult and expensive. A Riparian Buffer Conservation Zone Model
Ordinance was prepared by a consultant on behalf of the Ten Towns Great Swamp Watershed
Committee. It suggests a riparian buffer conservation zone of 75 feet. Please refer to page 63.
2. Natural Drainageways
Disturbance of natural drainageways can destroy natural vegetation that protects the soil
from erosion and with it the filtering capacity of the vegetation. This type of vegetation is among
the most difficult to reestablish. Natural drainageways contribute large amounts of runoff directly to
receiving lakes or streams. Once disturbed, they often become high-energy, high-volume conduits
for moving massive amounts of pollutants and large volumes of runoff to receiving waters.
Site plans that call for disturbing these natural drainage areas result in larger volumes of
water to manage and treat (and much greater costs for structural BMPs) than would be faced by
using other areas of the site for runoff management.
3.
Steep Slopes
Good site planning restricts the placement of houses and roads on steep slopes. Generally,
the steeper the slope, the greater the erosion hazard. This is because the effects of gravity and
reduced friction between soil particles on steep slopes means it takes less energy for water to
dislodge and transport soil particles. Figure 3.2 demonstrates that, as compared to flatter slopes,
steep slopes lead to greater areas of soil disturbance in order to accommodate facilities. A model
Steep Slope Ordinance prepared by the Ten Towns Great Swamp Watershed Committee's
consultant may be found on page 68. It suggests limiting steep slopes and earth disturbances to
25%.
Figure 3.2 Making Flat Areas for Homesites on Steep Slopes Disturbs More Land Area Than
on Flat Slopes
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Source: Minnesota Pollution Control Agency, 1989
4.
Dense Vegetation
A good site plan preserves large areas of existing dense vegetation. Good vegetative cover
is an extremely important factor in preventing erosion. Disturbance of areas with a well-established,
dense vegetative cover exposes valuable topsoil, making it highly susceptible to erosion. Wooded
areas with understory cover are the most runoff-absorbent types of cover in the landscape (SCS,
1986). Destruction of such vegetation adds significant expense to the construction budget for
clearing, and it destroys an inherently valuable attribute of the site. (Mature trees have recognized
value in real estate appraisals and market absorption rates for home sales forecasts.) In many cases,
sensitive areas can be used as buffer spaces between land uses on the site or as buffers to land uses
on adjacent sites (Figure 3.3). Mature woodlots can be used to provide visual screening and to
establish entry character, defining the boundary for the site.
Other areas can be used to preserve views from homesites and to provide privacy separation
between homesites such as along back property lines. Where preservation needs exceed the open
space requirement for development under straight zoning, cluster development under the planned
unit development (PUD) provisions of the zoning code generally can be used to avoid sensitive
areas while preserving the gross density allocated to the parcel.
9
Figure 3.3 Use Sensitive Areas Such as Natural Drainage Areas to Form Boundary Areas or
Buffer Zones Between Clusters of Housing
Source: Minnesota Pollution Control
Agency 5.
Erodible Soils
Site planning should try to minimize disturbing erodible soils in the land development
process and thereby avoid significant erosion and sedimentation problems. When denuded of
vegetation during construction, areas with easily eroded soils will yield greater volumes of
transported soil than those with erosion-resistant soils. The New Jersey Department of Agriculture
administers the Soil Erosion and Sediment Control Act which focuses on controlling erosion and
sediment from construction sites. Information on soil characteristics and erodibility can be obtained
from the U.S. Department of Agriculture Cooperative Soil Survey, available for most counties. The
soil surveys can be obtained through local Soil Conservation Districts or USDA Natural Resources
Conservation Service Offices (see Chapter 5).
Local governments must be cognizant of the fact that the impacts from development do not
end when the last of the construction equipment leaves the site. Water quality and quantity
problems remain and can even grow for decades. To provide long term water resource protection,
strategies must be developed using sound planning and site review techniques.
Redevelopment and Restoration
In a state such as New Jersey, where a large portion of the land has already been developed,
the concept of environmentally beneficial redevelopment becomes more important. A great many
commercial and industrial sites across the Whippany River watershed sit abandoned or underused.
These areas have been supplied with utilities and roads, and they have covered the soil with
impervious pavement and roof surfaces. Before utilities are extended to as yet undeveloped lands,
development should be directed to these areas. Developer tax breaks, low interest loans, and
liability relief for pre-existing conditions act as an incentive to redevelop. The concept is currently
being used in New Jersey and Pennsylvania for brownfields. Guidance for redevelopment can be
obtained from the New Jersey Office of State Planning.
10
Another beneficial re-use of abandoned impervious parking and road areas can be the
milling, reprocessing and re-use of the asphalt. In some cases, this can be economically feasible.
Subsequently, the site can be restored, vegetated with native trees and herbaceous plant species, and
become an environmental asset, especially if the restoration is done adjacent to a riparian zone.
Initially designed for flood control, many existing stormwater detention basins may be
retrofitted to reduce NPS pollution by extending the detention time for stormwater runoff. Funded
through a NPS grant from NJDEP, Rutgers University Department of Civil and Environmental
Engineering demonstrated in Morris Township that doing so will allow particle pollutants to settle
out and that the retention time of a small portion of runoff in a low marsh area will biologically
remove dissolved pollutants, nitrate nitrogen and orthophosphate in addition to about 80% of
suspended solids.
Summary
Many examples of effective mechanisms for lasting natural resource protection exist. A
Master Plan that delineates large wetland and buffer zones, together with appropriate zoning
of these regions, is one illustration of a long-term water quality protection tool.
Zoning ordinances that account for future development-related impacts could provide
municipalities with valuable tools for meeting water resource goals. For instance, decisions
based on predicted flooding problems in a partially-developed watershed could prevent
flooding before it happens. A resulting ordinance requiring that stormwater be released at a
rate that mimics nature at the outlet of a watershed can prevent future flooding and erosion
problems. Steep slopes, extended wetland buffers, riparian corridors, and cluster ordinances
help to ensure long-term water quality.
Site review procedures that allow for the up-front submission of sketch or concept
plans are effective because they allow applicants and the town to work together to better
protect natural resources without undue financial burdens on the applicant.
Using a range of available tools, local governments in the Whippany River watershed
have a responsibility to assure that long-term water resource goals are met. The planning and
site review procedures described in this chapter can help municipalities go a long way toward
protecting their valuable natural resources for future generations.
References
Association of New Jersey Environmental Commissions and NJDEP, 1992, The Environmental
Manual for Municipal Officials: Trenton, NJ.
Jones, D. Earl, 1971, "Where is Urban Hydrology Practiced Today?" Journal of the Hydraulics
Division, American Society of Civil Engineers Conference.
Heyer, Fred, 1990, Preserving Rural Character: Chicago, IL, American Planning Association, 20
pp.
Koppleman, L.E., E. Tanenbaum and C. Swick, 1984, Nonpoint Source Management Handbook.
Hauppauge, NY, Long Island Regional Planning Board.
Minnesota Pollution Control Agency, 1989, Protecting Water Quality in Urban Areas: St. Paul,
MN, Minnesota Division of Water Quality.
11
Moskowitz, Harvey S. and Carl G. Lindbloom, 1981, The Illustrated Book of Development
Definitions: Piscataway, NJ, Rutgers, The State University of New Jersey, 263 pp.
NISE and SCSC (Northeastern Illinois Soil Erosion and Sedimentation Control Steering
Committee), 1981, Procedures and Standards for Urban Soil Erosion and Sedimentation Control in
Illinois: Springfield, IL, Association of Illinois Soil and Water Conservation Districts. Soil
Conservation Service, 1986, Urban Hydrology for Small Watersheds: Technical Release 55:
USDA-SCS, Washington, D.C., Engineering Division.
USEPA, January 1993, Guidance Specifying Management Measures for Sources of Nonpoint
Pollution in Coastal Waters: Washington, D.C., Office of Water.
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