A. 
The subdivider shall be guided by the minimum planning and design development standards in design of the subdivision.
B. 
Where the Planning Board finds that, because of exceptional and unique conditions of topography, location, shape, size, drainage or other physical features of the site, or because of the special nature and character of surrounding development, the minimum standards specified herein would not reasonably protect or provide for public health, safety or welfare, a higher standard shall be required.
C. 
Land to be subdivided for building purposes shall be of such character that it can be used safely without danger to health or peril from flood or other menace.
D. 
Subdivisions shall conform to the Official Map and Chapter 201, Zoning, and be in harmony with the Comprehensive Plan.
A. 
Required improvements shall be installed by the subdivider to the satisfaction of the Planning Board's engineer prior to approval of final subdivision plat, or alternatively, the subdivider shall post a performance bond sufficient in amount to cover estimated full costs of such construction, as determined by the Planning Board.
B. 
The following are required improvements: monuments, lot markers; streets graded and improved with pavement; sidewalks; street signs; lighting standards; curbs and gutters; water mains; sanitary sewers; storm drains; fire hydrants; and trees, except where the Planning Board may waive, subject to appropriate conditions, such improvements as it considers are not requisite in the interest of the public health, safety and welfare.
A. 
Streets shall be suitably located, of sufficient width and adequately constructed to accommodate prospective traffic and to afford satisfactory access to fire-fighting, snow removal and road maintenance equipment.
B. 
Streets shall be arranged as to cause no undue hardship to adjoining properties and shall be coordinated so as to compose a convenient system.
C. 
The arrangement, width, grade and location of all streets shall be considered in relation to existing and planned streets, topographic conditions, public convenience and safety and in their appropriate relation to the proposed uses of the land to be served by such street.
D. 
Minor streets shall be planned so their use by through traffic will be discouraged.
E. 
Grades of streets shall conform as closely as possible to original topography and shall be arranged so that building sites are at or above street grade. A combination of steep grades and sharp curves shall be avoided.
F. 
Where a tract is subdivided into lots much larger than the minimum size required in the zoning district in which a subdivision is located, the Planning Board may require that streets and lots be laid out to permit future resubdivision.
G. 
Where the subdivision borders on an existing street and the Comprehensive Plan or Official Map indicates plans for realignment or widening of the street that would require reservation of some land of the subdivision, the Planning Board shall require that such areas be shown and marked on the subdivision plat "Reserved for Street Realignment (or Widening) Purposes."
H. 
The minimum building setback on a major street shall be 100 feet from the center line of such street. The minimum building setback on a collector street shall be 80 feet from the center line of such street.
I. 
Other standards.
(1) 
Intersections of major streets by other streets shall be held to a minimum and shall be at least 800 feet apart, if possible.
(2) 
Cross-street intersections shall be avoided, except at important traffic intersections.
(3) 
A distance of at least 250 feet shall be maintained between offset intersections.
(4) 
Within 100 feet of an intersection right-of-way, streets shall be approximately at right angles.
J. 
Half streets and privately owned reserve strips controlling access to streets or adjacent property shall be prohibited.
K. 
A circular turnaround shall be provided at the end of a permanent cul-de-sac street.
L. 
Arrangement of streets shall provide for continuation of existing streets between adjacent properties where such continuation is necessary for convenient movement of traffic, effective fire protection and efficient provision of utilities.
M. 
If adjacent property is undeveloped and the street must be a dead end temporarily, rights-of-way and improvements shall be extended to property line. A temporary circular turnaround shall be provided on all temporary dead-end streets, with the notation on the plat that land outside the street right-of-way shall revert to abutting lots whenever the street is continued.
A. 
Street design standards shall be as follows:
Major
Minor
Cul-de-sac
Minimum right-of-way width
80 ft.
50 ft.
50 ft.
Minimum pavement width
48 ft.
24 ft.
24 ft.
Maximum grade
5%
8%
5%
Minimum grade
0.5%
0.5%
0.5%
Minimum radius of curves, inner street line
800 ft.
150 ft.
150 ft.
Minimum tangent length between reverse curves
200 ft.
100 ft.
100 ft.
Minimum grades within 100 feet of center line intersections
1%
3%
3%
Minimum breaking sight distance
400 ft.
200 ft.
200 ft.
Minimum distance between center line offsets
400 ft.
250 ft.
250 ft.
Angle at intersections of street center lines
90°
85-95°
85-95°
B. 
Additional design standards for culs-de-sac:
(1) 
Maximum length: 900 feet.
(2) 
Turnaround radius: 60 feet.
(3) 
Minimum outside radius of pavement: 50 feet.
A. 
Street improvements shall be installed at the expense of the subdivider.
B. 
Streets must be constructed to comply with the detail specifications of the Planning Board.
C. 
Streets shall be built with:
(1) 
A subgrade which shall be rough graded the full width of the street right-of-way and compacted the full width between the outer edges of the curbs and gutter.
(2) 
A base course which shall be gravel.
(3) 
A surface course which shall be bituminous asphalt.
(4) 
Curbs and gutters which shall be concrete.
A. 
Sidewalks shall be installed at the expense of the subdivider, at such locations as the Planning Board may deem necessary.
B. 
Sidewalks must be constructed to comply with the detail specifications of the Planning Board.
C. 
Sidewalks shall be concrete and have a minimum width of four feet in residential areas and five feet in commercial and industrial areas.
A. 
The length, width and shape of blocks shall be determined with due regard to:
(1) 
Provision of adequate building sites suitable to the special needs of the type of use contemplated.
(2) 
Zoning requirements as to lot sizes and dimensions.
(3) 
The need for convenient access, circulation, control and safety of street traffic.
(4) 
Limitations and opportunities of topography.
B. 
Blocks indented by culs-de-sac, parking courts or loop streets and containing interior block parks or playgrounds will be acceptable when properly designed under provisions of a planned unit development in Chapter 201, Zoning, as determined by the Planning Board.
A. 
Lot size and shape shall comply with standards of Chapter 201, Zoning, and be appropriate for the type of development and use proposed, and shall be arranged so that there will be no foreseeable difficulties in securing building permits and gaining access to buildings from streets.
B. 
Subdivision plans shall provide each lot with satisfactory access to a public streets; driveway grades shall not exceed 10%.
C. 
Double-frontage and reverse-frontage lots shall be avoided where possible.
D. 
Where lots are more than double the minimum required area for the zoning district, the Planning Board may require that such lots be arranged so as to allow further subdivision.
E. 
Side lot lines shall be either at right angles or radial to street lines, unless a variation will give a better street or lot plan.
F. 
Corner lots shall have at least 10 feet more than minimum lot width specified in Chapter 201, Zoning, to permit compliance with building setback requirements.
A. 
Where conditions are such as to make impractical the inclusion of utilities or drainage facilities within street rights-of-way, perpetual unobstructed easements shall be provided, centered on rear or side lot lines with satisfactory access to the street.
B. 
Permanent utility easements shall be at least 10 feet in width and shall be so indicated on the plat.
C. 
The Planning Board may require perpetual unobstructed easements to facilitate pedestrian access to schools, public open space or streets. Pedestrian access easements shall be at least 20 feet in width, and shall be so indicated on the plat. The Planning Board may require a paved walk to be installed within the easement.
A. 
Permanent monuments shall be set at all corners and angle points of the subdivision boundaries; and at all street intersections, points of curve and at approximately five-hundred-foot intervals and their location shall be shown on the subdivision plat.
B. 
Monuments shall be stone or concrete with a one-inch diameter metal pipe at least two feet long set in the center, and located in the ground at final grade level.
C. 
Lot corner markers shall be 3/4 of an inch diameter metal pipe at least two feet long.
A. 
All streets shall be named subject to the approval of the Planning Board. A street which is a continuation of an existing street shall bear the same name.
B. 
Street name signs shall be furnished and installed by the subdivider. The type, size and location shall be to the approval of the Planning Board.
A. 
Outstanding natural features of the site, including groves of trees, watercourses and falls, historic spots, exceptional views and similar irreplaceable assets, shall be preserved as far as possible by harmonious design.
B. 
Trees over 10 inches in trunk diameter shall be preserved unless such trees are within the right-of-way of a proposed street.
C. 
Topsoil removed in the process of grading the subdivision site shall be replaced, except in proposed street, driveways and building locations.
On a residential lot, where none exists, at least three new trees shall be planted, located at least five feet outside the right-of-way. New trees shall measure at least two inches in diameter at a point six inches above finished grade level. Trees shall be hardy, suitable to local soil and climate and shall be of a species approved by the Planning Board.
A. 
Adequate stormwater drainage systems shall be required in all new subdivisions. An adequate drainage system shall mean one which has been designed by a licensed engineer to perform such work, who shall arrive at a logical conclusion based upon facts and estimates of a given situation and approval by the Planning Board.
B. 
Rights-of-way for stormwater drainage must be sufficient for facilities to handle not only the anticipated discharge from the property being subdivided but also the anticipated runoff that will occur when property at a higher elevation in the drainage basin is developed, based on a ten-year storm as defined by the USGS under conditions of total potential development.
C. 
The subdivider's engineer shall study the effect of the subdivision on existing drainage facilities downstream outside the subdivision. Where it is anticipated that runoff incident to the development of the subdivision will overload existing drainage facilities during a ten-year storm, the Planning Board shall not approve the subdivision until provision has been made for improvement of the downstream facility.
D. 
Where a subdivision is traversed by a watercourse, drainage way, channel or stream, there shall be provided a stormwater drainage easement conforming substantially with the lines of such watercourse, and of such width as to encompass the twenty-five-year flood area of such watercourse, which easement shall be so indicated on the plat.
E. 
Storm drainage system shall be constructed by the subdivider, in accordance with procedures and standards of the State Department of Health, if such drainage system is to be connected to or served by other municipally maintained drainage systems.
F. 
The subdivider shall present an individual lot drainage plan for each lot in the subdivision. Such plan shall be used in grading of lots before final approval of structures is granted.
G. 
Land subject to flooding or unsuitable for residential occupancy due to flood hazard shall be set aside for such uses as are not endangered by periodic inundation.
Floodland, areas bordering on major watercourses and drainage ways which cannot be used safely for building purposes without danger to health or peril from flood, may be offered as a gift, to be used as public open space or for recreational purposes.
A. 
A public water supply system shall be installed at the expense of the subdivider to the approval of the Planning Board's engineer.
B. 
The water supply system must be constructed to comply with the detail specifications of the Planning Board.
If, in the opinion of the Planning Board, service to each lot by a public water supply system is not feasible, the Planning Board may allow individual wells to be used, which shall be installed at the expense of the subdivider to the approval of the Planning Board's engineer, as follows:
A. 
Minimum lot sizes shall be 20,000 square feet in area, or in accordance with requirements of § 165-52, whichever is greater.
B. 
The water supply system shall be designed and installed to standards and procedures of the State Department of Health.
If, in the opinion of the Planning Board, service to each lot by a sanitary sewer system is not feasible, the Planning Board may allow individual septic tanks to be used, which shall be installed at the expense of the subdivider to the approval of the Planning Board's engineer, as follows:
A. 
Minimum lot sizes shall be in accordance with requirements of § 165-52.
B. 
The sewage disposal system shall be approved by the State Department of Health.
The following are minimum single-family residential lot sizes in areas without public sewage disposal and/or water supply system:
A. 
Where the average slope of lot does not exceed 10%:
Absorption Time for
1 Inch of Fall
(minutes)
Public Water and
Septic Tank
(square feet)
Private Well and
Septic Tank
(square feet)
0 - 10
25,000
35,000
11 - 20
30,000
40,000
21 - 30
35,000
45,000
31 - 40
40,000
50,000
41 - 50
45,000
55,000
Over 50
50,000
Not permitted
B. 
Where the average slope of lot is between 10% and 15%:
Absorption Time for
1 Inch of Fall
(minutes)
Public Water and
Septic Tank
(square feet)
Private Well and
Septic Tank
(square feet)
0 - 10
30,000
40,000
11 - 20
35,000
45,000
21 - 30
40,000
50,000
31 - 40
45,000
55,000
Over 40
50,000
Not permitted
C. 
Where the average slope of lot exceeds 15%:
Absorption Time for
1 Inch of Fall
(minutes)
Public Water and
Septic Tank
(square feet)
Private Well and
Septic Tank
(square feet)
0 - 10
35,000
45,000
11 - 20
40,000
50,000
21 - 30
45,000
55,000
31 - 40
50,000
60,000
Over 40
55,000
Not permitted
The following public utility improvements shall be installed:
A. 
Fire protection. Hydrants shall be of a size, type and location specified by the National Board of Fire Underwriters, American Insurance Association.
B. 
Streetlighting. Poles, brackets and lights shall be of a size, type and location approved by the local power company.
C. 
Electricity. Poles and power lines shall be approved by the local power company.
D. 
Utility services. Said services shall be located from six to eight feet from the front property line to the center line of the utility service between the sidewalk and curbline.