No building permit shall be issued and no site plan or subdivision shall be approved by any town department, agency or board for the development of land in any zoning district if any portion of the property is a Hillside Area until the provisions of this Article have been applied.

This Article shall apply to development in all zoning districts pursuant to a special use permit, use variance, area variance or other town-issued land-use approval.

This Article applies to the resubdivision of any lot included in a residential subdivision map and to residential site plan approved by the Planning Board before August 31, 2005.

This Article applies to new development on vacant lots and to new buildings which replace existing buildings on lots containing Hillside Areas.

Exemptions.

The average slope of a Hillside Area shall be calculated by measuring the rise (vertical) in elevation between consecutive contour lines that shall be shown at two-foot intervals on the map, and averaging the measurements taken at each twenty-five foot horizontal interval (run), or any remaining portion of an interval as needed to reach the property boundary. The measurements shall be taken perpendicular to the lower contour lines. The total rise (vertical measurements) shall be divided by the total run (horizontal measurements) to reach the resulting average slope percentage. The average slope percentage shall be stated to two (2) decimal points or hundredths (e.g. 18.25). If this calculation is generated by the applicant on a computer using computer aided design software (CAD), proof shall be submitted in digital format that is readable in the software program used by the Town. Such calculation shall be subject to review and approval by the Director of Planning and Environment.

Any Hillside Area that will be protected by a permanent conservation easement preventing construction, clearing and grading shall not be included in the calculation of the average slope of a Hillside Area. The conservation area shall be of a size and shape sufficient to protect steep slopes as determined by the Director of Planning and Environment or the Planning Board, as the case may be. The conservation area shall not consist of scattered noncontiguous areas throughout a lot. Covenants and restrictions establishing a conservation area which preserves the Hillside Area in their natural state in perpetuity shall be submitted to the Town Attorney for approval as to form and content. The Town Attorney shall indicate approval by signing the original document. The applicant shall record the signed original document in the Office of the Suffolk County Clerk at his or her own cost and expense and provide the Town Attorney, Department of Planning and Environment and Department of Engineering Services with a copy of the recorded instrument.

The number of lots for that portion of a subdivision which is not a Hillside Area shall be determined by the Planning Board in accordance with current zoning requirements and subdivision regulations for the zoning district in which the property is located.

Lot yield. The number of lots permitted in a Hillside Area shall be determined by calculating the average slope percentage of such Hillside Area and applying the lot yield factor shown in the following table.

The number of lots to be permitted in the subdivision shall be the total yield from the Hillside Area and the flat area, if a flat area is determined to exist. If there is no flat area, then the total number of lots shall be those yielded from the Hillside Area. The yield calculation for the Hillside Area shall be rounded from the hundredths position to the nearest whole number [e.g., one and one-half (1.50) requires two (2) large lots; one and forty-nine one hundredths (1.49) requires one (1) large lot].

Lot yield alternative. At the applicant’s discretion, as an alternative to the lot yield method provided in (B) and (C) above, lot yield may be determined by deducting Hillside Areas from the yield of the property in their entirety. Lots in the flat portion(s) of the property shall meet the zoning requirements for the district in which they are located without using any area(s) within the Hillside Area. As a condition of approval, if this alternative is utilized no portion of the Hillside Area(s) shall be built upon or developed. Covenants and restrictions establishing a conservation area which preserves the Hillside Area(s) in their natural state in perpetuity shall be submitted to the Town Attorney for approval as to form and content. The Town Attorney shall indicate approval by signing the original document. The applicant shall record the signed original document in the Office of the Suffolk County Clerk at his or her own cost and expense and provide the Town Attorney and Department of Planning and Environment with a copy of the recorded instrument. The liber and page of each instrument recorded shall be shown on the final subdivision map submitted to the Director of Planning and Environment before the final map will be signed by the Director.

Any oversized lot that is created pursuant to (B) above shall be considered to be fully yielded and is not to be further subdivided. The applicant shall submit covenants and restrictions explaining the reason(s) the lot was created and prohibiting further subdivision of the newly created lot in perpetuity to the Town Attorney for approval as to form and content. The Town Attorney shall indicate approval by signing the original document. The applicant shall record the signed original document in the Office of the Suffolk County Clerk at his or her own cost and expense and provide the Town Attorney and Department of Planning and Environment with a copy of the recorded instrument. The liber and page of each instrument recorded shall be shown on the final subdivision map submitted to the Director of Planning and Environment before the final map will be signed by the Director.

Park set-aside requirements: In all cases, the requirement for parkland set-aside shall be determined from the portion of land used to calculate lot yield.

In the event a lot(s) on a proposed map does not comply with the area requirements of this article, an applicant may seek a variance from the Zoning Board of Appeals. All applications to the Zoning Board shall include a topographical survey showing contour lines at two-foot intervals as provided in § 198-62, grading plans with tree clearing limits shown, and any other proof requested by the town. In entertaining such an application, the Zoning Board of Appeals shall seek the recommendation of the Planning Board with respect to the variance sought. The Planning Board shall, using generally accepted planning principles, make the final determination of the number of lots permitted in Hillside Areas in keeping with the spirit and intent of this article, the applicable provisions of the Town Code, and Town Law § 277(1) and (2), or successor law.

No building permit to construct, clear or grade land for residential development on individual residential building lots containing Hillside Area(s) shall be issued until the provisions of this article have been applied.

Procedure. All building permit applications filed in the Department of Engineering Services shall include photographs of the property from the street and photographs of the areas of the lot affected by the proposed construction, clearing and/or grading. A sworn and notarized affidavit signed by the property owner shall be submitted with the application attesting that the parcel has no Hillside Areas; or if it does, that no part of the proposed work, clearing and/or grading will occur in such areas. In addition to an affidavit from the property owner, the Director of Engineering Services may, at his discretion, request a sworn and notarized affidavit by a licensed surveyor or professional engineer bearing the original seal and attesting that the parcel has no Hillside Areas or that the proposed construction, clearing and/or grading will not be performed in such areas. The Director may also require a topographical survey showing elevations at two (2) foot intervals. If a field inspection determines that a false statement or misrepresentation has been made, a stop-work order shall be issued and the permit revoked. The applicant will be required to file a new building permit application, pay the requisite fees, and go through the review provided by this Article. In all cases, a topographical survey, grading plans with tree clearing limits shown, and any other proof requested by the town will be required for construction, clearing or grading in Hillside Areas.

The Department of Engineering Services shall forward all building permit applications not exempted by this article including topographical surveys and plans to the Director of Planning and Environment for review prior to issuing building permits. The Director of Planning and Environment shall make the final determination of the average slope percentage and such determination shall control further review of the application for a building permit. Any person aggrieved by the determination of the Director of Planning may pursue his/her remedies in a court of competent jurisdiction.

Review. If the average slope percentage is ten (10%) percent or greater, the Department of Planning and Environment will review applications for compliance with this Article. The review will take into consideration the degree of slope and size of the sloped area affected by construction; the attempt by the applicant to minimize or mitigate development on steep slopes; the locations of proposed and/or existing buildings, accessory structures, freestanding and retaining walls; the location of driveways and lawn areas; soil classifications; flora and fauna; unique environmental features; neighborhood impacts and other factors deemed necessary by the Department.

The Director of Planning and Environment may require changes to a building permit application in order to protect steep slopes and the environment, and may require such conditions and restrictions as deemed necessary to assure compliance with all applicable laws, rules and standards. Development shall be confined to the least-sloped portion of the property whenever appropriate, taking into account the degree of slope, the suitability of the location for construction, attempts to mitigate clearing and grading, the environmental features of the lot, and compliance with the intent of this article. If the Director of Planning and Environment determines that a proposed development will result in significant impacts to steep slopes, the application will be forwarded to the Planning Board for review. The Planning Board may approve or deny the application, in whole or in part, with or without conditions. Any person aggrieved by the determination of the Director of Planning and Environment or Planning Board may pursue his/her remedies in a court of competent jurisdiction.

Compliance with conditions. If the Planning Board or Director of Planning and Environment requires that covenants and restrictions be filed as a condition of receiving a building permit for work in a Hillside Area, the applicant shall submit the covenants and restrictions to the Town Attorney for approval as to form and content. The Town Attorney shall indicate approval by signing the original document. The applicant shall record the signed original document in the Office of the Suffolk County Clerk at his or her own cost and expense and provide the Town Attorney, the Department of Planning and Environment, and the Department of Engineering Services with a copy of the recorded instrument before any permits can be issued by the Department of Engineering Services. Any permit issued before the covenants are filed and all other conditions are met shall be null and void.

Building Footprint. If any portion of the proposed building footprint is in a Hillside Area, the building footprint shall be subject to the maximum ground floor area shown in the following chart:

Method of calculating the building footprint. The maximum building footprint permitted by this Article shall be calculated as follows:

A lot modified by the Planning Board pursuant to Town Law § 278 shall be subject to the building footprint limits which would have applied had no modification taken place.

Any person seeking a variance from the area requirements of this section may apply to the Zoning Board of Appeals, the Zoning Board shall seek the recommendation of the Planning Board with respect to any variance sought. All applications to the Zoning Board shall include a topographical survey showing contour lines at two-foot intervals as provided in § 198-62, grading plans with tree clearing limits shown, and any other proof requested by the town.

Accessory structures. In no event shall the ground floor area exceed the following designated limits:

No site plan approval for construction, clearing or grading in a Hillside Area shall be granted by the Planning Board until the provisions of this article have been applied.

The average slope of a Hillside Area shall be calculated in accordance with the provisions of § 198-62.

The number of living quarters (in the case of an assisted living facility) or dwelling units permitted in the flat area(s) shall be determined by the Planning Board in accordance with current zoning requirements and site improvement specifications for the zoning district where the property is located.

Yield determination. The number of dwelling units or living quarters permitted in a Hillside Area shall be determined by calculating the average slope percentage and applying the yield factor shown in the following table. In the event the Town Code provides for different minimum area requirements, the stricter requirements shall apply to Hillside Areas. The yield calculation shall be rounded down to the nearest whole number (e.g., 8.8 = 8 units).

The total number of living quarters or units permitted shall be the total yield from the Hillside Area and the flat area, if a flat area is determined to exist. If there is no flat area then the total number permitted shall be those yielded from the Hillside Area.

In the event an applicant seeks a variance of the above area requirements from the Zoning Board of Appeals, the Zoning Board shall seek the recommendation of the Planning Board with respect to the variance sought. All applications to the Zoning Board shall include a topographical survey showing contour lines at two-foot intervals as provided in § 198-62, grading plans with tree clearing limits shown, and any other proof requested by the town. The Planning Board shall make the final yield determination in Hillside Areas in keeping with the spirit and intent of this article, the applicable provisions of the Town Code and Town Law § 274-a, or successor laws.

Accessory structures.

The Planning Board may require changes to a site plan in order to protect steep slopes and the environment, and may require such conditions and restrictions as deemed necessary to assure compliance with all applicable laws, rules and standards. The Board will confine development to the least-sloped portion of the property whenever appropriate, taking into account the degree of slope, the suitability of the location for construction, attempts to mitigate clearing and grading, the environmental features of the lot, and compliance with the intent of this article. Any person aggrieved by the determination of the Planning Board may pursue his/her remedies in a court of competent jurisdiction.

No building permit, site plan, special use permit or variance shall be approved, granted or released by any town department, agency or board for development requiring site plan review by the Planning Board and which is not covered by § 198-65 if any portion of the property is a Hillside Area until the provisions of this article have been applied.

Application requirements. All applications for the development of land containing Hillside Areas, including all applications before the Zoning Board of Appeals, shall include a topographical survey showing contour lines at two-foot intervals as provided in § 198-62, grading plans with tree clearing limits shown, and any other proof requested by the town.

Site plan approval. As a condition of site plan approval, a portion of the Hillside Area shall be permanently preserved in its natural state in perpetuity by means of a conservation easement whose size shall be calculated by using the following table. The conservation easement shall prohibit clearing, grading and other construction activity, but may permit the area to be landscaped as necessary to prevent erosion or to provide required buffers where feasible, as determined by the Planning Board. The Planning Board may redesign the conservation area in order to permit reasonable use of the property if the preservation of such area reduces potential development of the site by more than fifty (50%) percent.

Covenants and restrictions explaining why the conservation easement is being established and preserving such portion of Hillside Area(s) in their natural state shall be submitted to the Town Attorney for approval as to form and content. The Town Attorney shall indicate approval by signing the original document. The applicant shall record the signed original document in the Office of the Suffolk County Clerk at his or her own cost and expense and provide the Town Attorney and Department of Planning and Environment with a copy of the recorded instrument. The liber and page of each instrument recorded shall be shown on the site plan submitted to the Director of Planning and Environment before the plan will be signed for final approval.

Retaining walls. Retaining walls greater than four (4) feet and less than or equal to five (5) feet in height shall be located at least ten (10) feet from residential property lines and five (5) feet from all other property lines. Retaining walls greater than five (5) feet in height shall be located at least fifteen (15) feet from residential property lines and ten feet from all other property lines.

Authority of the Planning Board.

Authority of the Zoning Board of Appeals.