Frequently Asked Questions about the

Special Natural Area District
Zoning Regulations

(Zoning Resolution of the City of New York, Article X, Chapter5)

Disclaimer:  This guide is not to be considered a substitute for the actual Zoning Resolution. 

Click on the links below to go directly to that question.

IMPORTANT PHONE NUMBERS

What is the purpose of the Special Natural Area District?

How do I know if my property is in the SNAD?

Why hasn't my property been subject to review in the past?

What are my responsibilities under the new regulations?

What types of review might be required for my project?

What is the process for obtaining a certification, authorization, or special permit?

What is a Notice of Restrictions/Restrictive Declaration?

Which natural features are protected?

What are the new categories Tier I and Tier II?

What if I want to replant my garden with different types of vegetation?

Must I preserve every tree on my property?

Do the changes affect what can be built on my property?

What can I build on steep slopes?

How are SNAD zoning regulations enforced?

Introduction

The Special Natural Area District (SNAD) is a special zoning district overlay that provides added protections for an area’s natural features, without changing or altering the requirements of the underlying zoning. In most cases, a development, site alteration, or enlargement must be reviewed by the Department of City Planning to evaluate impacts on natural features. The SNAD was mapped in Riverdale in 1975 and covers approximately one-half of Bronx Community District 8. Two other SNADs are mapped in Staten Island and one is mapped in Queens.

A substantial revision to the SNAD regulations was adopted by the New York City Council on February 2, 2005. The following material explains some aspects of the current regulation.

What is the purpose of the Special Natural Area District?
Section 105-00 of the zoning regulations states that the goals of the Special Natural Area District are to:

• Guide development in areas of outstanding natural beauty in order to protect, maintain and enhance the natural features of such areas;

• Preserve land having qualities of exceptional recreational or educational value to the public;

• Protect aquatic, biologic, botanic, geologic and topographic features having ecological and conservation values and functions;

• Reduce hillside erosion, landslides and excessive storm water runoff associated with development by conserving vegetation and protecting natural terrain;

• Preserve hillsides having unique aesthetic value to the public; and

• Promote the most desirable use of land and the direction of building development in accordance with a well-considered plan, to promote stability of residential development, to promote the character of the district and its peculiar suitability of particular uses, to conserve the value of land and buildings, and thereby protect the City’s tax revenues.

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How do I know if my property is in the SNAD?
The Department of City Planning maintains zoning maps on their web site. The area of the SNAD is shaded in grey. The maps can be accessed at Zoning Map Index - New York City Department of City Planning.  If your property is near the boundary line of the SNAD and it is not clear to you whether your particular lot is included, you can call the Bronx office of the Department of City Planning at
718-220-8500.

Why hasn't my property been subject to review in the past?        

The types of work that you have undertaken in the past may have been exempt from review under the old SNAD regulations.  Under the old regulations, zoning lots of 40,000 square feet or less, that had a residential building on them at the time the property was included in the SNAD, did not have to comply with SNAD regulations for site alterations.  Site alterations include such work as removing protected vegetation, land contour work, removing top soil, change in existing drainage systems, relocation of erratic boulders, or modification of any other natural feature.

SNAD regulations also did not apply to enlargements of residential buildings that existed on the date of inclusion in the SNAD, regardless of lot size.

What are my responsibilities under the SNAD regulations?

As a property owner, you should become familiar with the goals and requirements of the SNAD.  You are responsible for protecting significant natural features on your property whenever you propose to undertake any new construction, expansion, or site alteration.

Contact the Bronx Office of the Department of City Planning if you have specific questions.

What types of review might be required for my project?
You should alway begin a project with a phone call to the Bronx Office of City Planning.  Planners there will determine which of the four levels of review apply to your project.  The levels are:

      As-of-right -- if your property and project meet certain criteria for size and there are no significant natural features on your site, you may be able to apply directly to the Department of Buildings (DOB) for a building permit, without review by City Planning. The criteria are provided in section 105-021 of the zoning text.

     Certification -- If your site does contain significant natural features, but your project can meet specific criteria for protecting and planting vegetation, for the amount of lot coverage, and for grading and construction controls, you probably only need to obtain a certification that you meet the criteria from the Department of City Planning (DCP).  The specific criteria are detailed in sections 105-31 through 105-36 of the zoning text.

     Authorization -- If you find it necessary to modify the requirements of sections 105-31 through 105-36, cited above, or if your project will have an impact on aquatic features or geologic or topographic features, including steep slopes, or if you seek to modify bulk, parking, grading, or private road regulations, you will need to apply for authorization from the City Planning Commission (CPC). Sections 105-421 through 105-434 specify the criteria that the Commission uses to evaluate the necessity and appropriateness of an application for authorization.

Although authorizations are referred to the community board, unlike a full ULURP review (see next question), they do not require public hearings at the CPC or City Council level. After the review process, the Commission grants authorization at its discretion. Hence, authorizations as well as special permits are known as discretionary reviews.

     Special Permit -- If you seek to modify the underlying zoning district regulations with respect to housing density and commonly-held open space, you will need a special permit. Sections 105-441 and 105-442 of the zoning text detail special permit requirements. Special permits require full ULURP review (see below).

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What is the process for obtaining a certification, authorization, or special permit?
The first step in the process is to schedule a pre-application meeting with the Bronx Office of City Planning. Staff will guide you through the application process.

A Land Use Review Application must be filed at the Department of City Planning (DCP). Applications and instructions are available on-line from the DCP web site at New York City Department of City Planning.  In the blue area at the left, click on Land Use Process then Land Use Review Forms. Section 105-022 of the SNAD regulations specifies additional materials that must be included with the application for work in the SNAD, and who may prepare them.

     Certification -- as noted above, an application for a certification is reviewed by DCP staff. If zoning requirements are met, the DCP will issue a certification to the Department of Buildings (DOB) that the application complies with applicable SNAD regulations.

     Authorization -- Authorization involves preparation of either a Notice of Restrictions or a Restrictive Declaration (depending on the complexity of the proposal), which details the preservation requirements for your project. The DCP seeks to resolve any community concerns and often asks the community board for its review. Finally, the City Planning Commission (CPC) considers the application against evaluation criteria set forth in sections 105-421 through 105-434 of the zoning text. If the Commission grants the authorization, the Notice of Restrictions or Restrictive Declaration is recorded with the City Register and the DOB.

     Special Permit -- Special permits are subject to the City Environmental Quality Review (CEQR) procedure and the Uniform Land Use Review Procedure (ULURP). The full procedures are described on the DCP web site.

In brief, procedures leading up to city council hearing include preparation of a Notice of Restrictions or a Restrictive Declaration; determination of the environmental impact of the project under CEQR; community board public hearing; review by the borough president; and a public hearing by the CPC. The Commission approves, modifies, or disapproves the application. The City Council may elect to review a special permit approved by the CPC. Other requirements are in place for City Council review if the special permit is disapproved by the CPC. If the application is approved, the Notice of Restrictions or Restrictive Declaration is recorded with the City Register and the DOB.

What is a Notice of Restrictions/Restrictive Declaration?
A Notice of Restrictions or Restrictive Declaration places conditions on the future use and development of the land. These covenants run with the land and give notice to all present and future owners of the conditions and restrictions associated with the site plan approved by the Commission.

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Which natural features are protected?
The list of natural features remains unchanged, and includes:

Rock outcrops

Geologic deposits such as erratic boulders, glacial formations, and mineral deposits.

Steep slopes, which are defined as slopes at or greater than 25 percent

Existing natural topography

Topsoil

Aquatic features, such as beaches, wetlands, swamps, meadows, creeks, lakes, ponds, and natural springs.

Botanic environments, including primary succession communities, secondary succession communities, climax communities, dunes, heathlands, and wild grasslands.

Trees of 6” caliper or greater in size. Caliper is the diameter of the tree trunk measured 4 feet 6 inches from the ground. If a tree splits into multiple trunks below this height, it is measured at its most narrow point beneath the split.

What are the new categories Tier I and Tier II?
The concept of Tier I and Tier II originated with the Special Hillsides Preservation District and refers to the slope of the site. Tier I refers to sites with an average percent of slope of less than 10 %. Tier II sites have an average percent of slope of 10 % or greater.

Average percent of slope is the average slope of all portions of a zoning lot, excluding steep slopes. Section 105-01 (definitions) of the regulations includes a formula for calculating the average percent of slope.

What if I want to replant my garden with different types of vegetation?
The SNAD regulations protect vegetation that is part of a botanic environment, as defined in section 105-11 of the regulations and outlined above, and monitor the removal of large amounts of vegetation from a site. Keep these purposes in mind, and in most cases it will be clear whether review is required for your project. For example, if your project will affect a botanic environment or a tree of 6” caliper or more, or if you plan to remove a broad area of vegetation that will not be replanted, you will need a review. If you are contemplating replacement of, for example, a lawn area with a flower bed, the area will remain planted and no significant features will be affected. Review should not be necessary. If in doubt, call the Bronx office of the Department of City Planning for guidance.

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Must I preserve every tree on my property?
No. Trees of 6” caliper or greater are significant resources and subject to protection. Section 105-01 of the zoning regulations define “caliper” as the diameter of a tree trunk measured 4 feet 6 inches from the ground. If a tree splits into multiple trunks below 4 feet 6 inches from the ground, the trunk is measured at its most narrow point beneath the split.

It is not necessary to apply for a review to remove a tree that is smaller than 6” caliper.

A tree of 6” caliper or greater in size that is dead, diseased, or imminently hazardous to property or persons may also be removed without special review. When removing such a tree, you must obtain a letter from a certified arborist documenting the tree’s condition and justifying its removal.

Healthy trees of 6" caliper or more that are being removed as a result of a development, enlargement, or site alteration, must meet one of the following criteria.  See section 105-31 of the regulations for a full discussion. 

• The tree is located in areas to be occupied by your development project,

• The continued presence of the tree would create special hazards or dangers to persons or property,

• The tree will interfere with the growth or health of another tree that is designated for preservation, or

• An authorization has been granted by the City Planning Commission approving its removal.

Trees on a property are counted by “tree credits”. Any site alteration, construction, or expansion must provide one tree credit for each 1,000 square feet of lot area, or 51% of the original tree credits, whichever is greater, regardless of whether the project removed any trees. A tree credit is a credit for preserving an existing tree of 6" caliper or more that is counted toward a tree preservation requirement or a credit for a newly-planted tree of 3" caliper or more that is counted toward a tree planting requirement.  (Section 105-01)  Trees of 6" caliper or more that are preserved count as one tree credit for the first 6" of diameter and one additional tree credit for each additional 4" of diameter.

Section 105-32 provides detailed guidance on tree planting.

Do the changes affect what can be built on my property?
Land uses and building bulk controls are regulated by the underlying zoning, which in most cases in the Bronx SNAD is R1-2. These regulations remain unchanged, with one exception.

To reduce disturbances of slopes and the erosion and stormwater problems that can result, the new SNAD regulations incorporate lot coverage controls that have been successfully used in the Special Hillsides Preservation District. Lots with an average percent of slope of 10 % or greater are governed by the lot coverages in Tables 1 and 2 of section 105-33. Quite simply, lot coverage is the percentage of a lot that can be covered by a building. As slope increases, the permitted coverage decreases. In all cases, coverages are less than what is allowed by the R1-2 zoning, which is the base zoning over most of the SNAD. (R1-2 uses the open space ratio (OSR) to determine open space on a property. While the calculation methods are different, the OSR and lot coverage methods both determine the percentages of building footprint and open space allowed on a lot.) If necessary, you can apply for authorization from the City Planning Commission to exceed the coverage limits in Tables 1 and 2, up to the maximum allowed by the base zoning.

Zoning maps and regulations are available on the Department of City Planning website at New York City Department of City Planning.  Click on zoning in the blue area at the left on the home page, and choose zoning maps or zoning text.

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What can I build on steep slopes?

The new regulations change three aspects of development on steep slopes:

• The definition of steep slope is changing from a 15 % or greater grade to a 25 % or greater grade. (25 % grade is a rise of one foot in elevation for each four feet of horizontal distance.)

• In the Bronx SNAD, development on a steep slope will now need authorization from the CPC instead of a special permit.

• In an R1 zone, if a building proposal includes building on all or part of a steep slope, the building may cover up to 12.5 % of the lot. The old regulations did not impose maximum lot coverages.

The type of building that can be built and building bulk are controlled by the underlying residential zoning and are not affected by these changes to the SNAD regulations.

Additionally the new zoning regulations continue to require that for residential developments on individual zoning lots “substantially within a steep slope area” (steep slopes on at least 50 % of the lot), the lot area per dwelling unit …shall not be less than 12,500 square feet (section 105-50, l (1)). This requirement carries over from the old regulations. It is important to remember that the requirement applies to zoning lots, not tax lots, which can be smaller. Smaller zoning lots that were created prior to December 19, 1974 are considered preexisting, non-complying lots, and development is not automatically precluded. Subdivision of zoning lots must be reviewed by the City Planning Commission for compliance with this provision, among others (section 105-90).

How are SNAD zoning regulations enforced?
The Department of Buildings enforces zoning regulations. If you believe someone is in violation of the zoning regulations, you can report your observations to the city’s 311 phone center. You must provide an address, or if in the case of new construction there is no address, the block and lot or nearest street intersections. An inspector will be sent out and a stop work order or notice of violation issued as appropriate.

If natural features have been removed illegally, the Department of City Planning may require a restoration plan as part of removing the violation. The owner must pay the cost of the restoration and a fine.