A.
Districts. For the purposes of the design standards (Article III), the required improvements (Article IV) and the typical street cross sections, the Town of Sunderland is hereby divided into two (2) districts designated "The Mountain" and "The Plain." These are shown on the Subdivision Districts Map. That map and all explanatory matter thereon is hereby made a part of this regulation.[1] It is recommended that subdivision plans follow the design
guidelines contained in Appendix A.[2]
[1]
Editor's Note: Said map is on file in the Town offices.
[2]
Editor's Note: Appendix A is included at the end of this chapter.
B.
Design guides. The subdivision shall be designed consistent with
these standards and with the guidelines of Appendix A. The subdivision
shall conform, insofar as practical, to any elements in a Town development
policy which the Planning Board may adopt, provided that such elements
are given public hearing in the same manner as prescribed for amendments
to subdivision regulations and made available along with copies of
the subdivision regulations.
A.
Location and alignment.
(1)
All streets and paths in the subdivision shall be designed to provide
safe pedestrian and vehicular travel and shall be certified by the
designer to meet the Massachusetts Highway Design Manual, except where
these regulations create a different standard. Due consideration shall
also be given by the subdivider to the consequences of the street
layout upon the livability, amenity and environmental impact of the
subdivision.
(2)
Provision satisfactory to the Board shall be made for the proper
projection of streets and paths or for access to adjoining property
which is not yet subdivided, including extending street and path rights-of-way
and physical streets and paths to the property line. A nonrevocable,
nonexpiring offer of dedication shall be provided to allow that these
streets, paths, and accessways could be used for future access to
adjoining property. Reserve strips, covenants, deed restrictions or
other legal or physical methods of prohibiting access to streets or
adjoining property shall not be permitted, except where, in the opinion
of the Board, the adjoining property would not benefit from such access
because of environmental limitations (e.g., wetlands) or legal restrictions
(e.g., conservation land where access is not desirable).
(3)
Street jogs with center-line offsets of less than one hundred fifty
(150) feet are prohibited.
(4)
Street configuration shall be designed, together with reserved open
space, to minimize the number of lots having frontage exclusively
on collector streets.
(5)
The minimum center-line radii of curved streets shall be not less
than the following:
|
Type of Street
|
Mountain
(feet)
|
Plain
(feet)
| |
|---|---|---|---|
|
Lane
|
50
|
75
| |
|
Minor streets
|
100
|
150
| |
|
Collector streets
|
250
|
350
|
(6)
Streets shall be laid out so as to intersect as nearly as possible
at right angles. No street shall intersect any other street at less
than eighty degrees (80°) or ninety degrees (90°) if one of
the streets is a collector street.
(7)
Any subdivision or portion thereof containing ten (10) or more lots
shall be provided with at least two (2) outlets to a public way.
(8)
Property lines at street intersections shall be rounded or cut back
to provide for a radius at the edge of the traveled way of not less
than thirty (30) feet at intersections with a collector street and
not less than twenty (20) feet for intersections involving only minor
streets or lanes.
(9)
Street intersections on arterial streets (major intertown streets)
shall be spaced not less than four hundred (400) feet apart.
(10)
All streets shall include provision for off-road pedestrian
travel on adjacent sidewalks and/or on separate trails or pathways.
Said trails or pathways do not necessarily need to follow the streets
if other locations are likely to provide more enjoyable and/or more
direct paths to likely pedestrian destinations. When located within
the street right-of-way, sidewalks, paths, and trails shall be located
at or near the outside of the layout but varied in horizontal location
so as to minimize disturbance of natural features of the land and
vegetation.
B.
Width.
(1)
The minimum width of street rights-of-way and traveled way width,
exclusive of curbing, shall be in accordance with the following requirements.
In the event on-street parking is proposed, four (4) feet should be
added to the minimum traveled way width.
|
Minimum Right-of-Way Width
| |||
|---|---|---|---|
|
Type of Street
|
Mountain
(feet)
|
Plain
(feet)
| |
|
Lane
|
33
|
33
| |
|
Minor
|
40
|
40
| |
|
Collector
|
50
|
50
| |
|
Minimum Traveled Way Width
| |||
|---|---|---|---|
|
Type of Street
|
Mountain
(feet)
|
Plain
(feet)
| |
|
Lane
|
16
|
18
| |
|
Minor
|
18
|
20
| |
|
Collector
|
20
|
24
| |
|
Minimum Surface Type
| ||
|---|---|---|
|
Type of Street
|
Materials
| |
|
Lane
|
Bituminous concrete
| |
|
Minor
|
Bituminous concrete
| |
|
Collector
|
Bituminous concrete
| |
(2)
The minimum width of rights-of-way for sidewalks located outside
of a street right-of-way shall be ten (10) feet, and the minimum width
of rights-of-way for bicycle paths located outside of a street right-of-way
shall be 20 feet.
C.
Grade.
(1)
Grades of streets shall be not less than five-tenths percent (0.5%).
Grades of streets shall be not more than the following:
|
Type of Street
|
Mountain
(feet)
|
Plain
(feet)
| |
|---|---|---|---|
|
Lane
|
10%
|
8%
| |
|
Minor street
|
8%
|
6%
| |
|
Collector street
|
6%
|
6%
|
(2)
On any street where the grade exceeds six percent (6%) on the approach
to an intersection, a leveling area with a slope of not more than
four percent (4%) shall be provided for a distance of not less than
fifty (50) feet measured from the nearest exterior line of the intersecting
street.
(3)
Vertical curves are required whenever the algebraic difference in
grade between center-line tangents is two and zero-tenths percent
(2.0%) or more.
(4)
Street center-line profile shall at no point be less than three (3)
feet above the grade of adjacent wetlands or marsh.
D.
Sight distances. Forward-stopping sight distances shall be not less
than the table below and in accordance with American Association of
State Highway and Transportation Officials (AASHTO) standards for
very-low-volume local roads, except where collector streets require
AASHTO standards for highway and streets. Designers are encouraged
to utilize physical measures to calm streets prior to intersections
to slow the speed of streets and thereby allow shorter stopping distances:
|
Type of Street
|
Mountain
(feet)
|
Plain
(feet)
| |
|---|---|---|---|
|
Lane
|
150
|
175
| |
|
Minor street
|
200
|
220
| |
|
Collector street
|
400
|
490
|
E.
Dead-end streets.
(1)
Dead-end streets shall not be allowed, except for lanes, unless,
in the opinion of the Board, they are necessitated by topography or
other local conditions.
(2)
Dead-end streets shall be provided at the closed end with either
a turnaround having an outside roadway diameter of at least eighty
(80) feet and a property line diameter of at least one hundred (100)
feet or, if authorized by the Planning Board, an alternative configuration
accommodating the turning of a vehicle with a wheelbase of thirty
(30) feet.
A.
Easements for utilities across lots or centered on rear or side lot
lines shall be provided where necessary and shall normally be twenty
(20) feet wide.
B.
Where a subdivision is traversed by a watercourse, drainageway, channel
or stream, the Board may require that there be provided a stormwater
or drainage easement of a minimum width of twenty (20) feet, to conform
substantially to the lines of such watercourse, drainageway, channel
or stream, and to provide for construction or other necessary purposes.
C.
Drainage easements outside of the area of the subdivision, but occasioned
by it, may be required of the subdivider.
D.
Cut or fill slopes shall be contained within the street right-of-way.
A.
Storm drainage, culverts and related facilities shall be designed
to permit the unimpeded flow of all natural watercourses, to ensure
adequate drainage of all low points along streets, to control erosion
and to intercept stormwater runoff along streets at intervals reasonably
related to the extent and grade of the area drained. Catch basins
shall be located at all low points and sags, near the corners of the
roadway at intersecting streets and at intervals of not more than
three hundred fifty (350) feet on continuous grades. To the maximum
extent feasible, stormwater shall be recharged rather than piped to
surface water. Peak stream flows at the boundaries of the development
shall be not more than five percent (5%) higher following development
than prior to development.
B.
Storm sewers, retention basins and leaching basins shall be based
on a one-hundred-year-frequency storm, and culverts shall be based
on a one-hundred-year-frequency storm. The design shall employ backflow
valves or other devices as necessary to avoid damage from reverse
circulation of floodwaters and on flooding of the Connecticut River
to the levels indicated on the Map of Flood-Prone Areas, prepared
in 1959 by United States Geological Survey.
C.
Design shall be based upon either the Rational Method or the Manning
Formula. Water velocities shall be between two (2) and ten (10) feet
per second. The coefficient of runoff used shall be not less than
forty-five hundredths (0.45) for subdivided areas. All developable
land tributary to facilities being designed shall be assumed to be
subdivided, except within the Mountain District and land classified
Class I or Class II Agricultural capability by the United States Soil
Conservation Service. Leaching basins or a catch-basin-to-manhole
system of drainage is required, with no storm sewers of less than
a twelve-inch inside diameter. Where used, leaching basins shall be
cross-connected. The Board may require test borings at leaching basin
locations where percolation is in doubt.
A.
Provisions shall be made for water supply to each lot and for fire
protection and sewage disposal. When available, the water supply shall
be from the Sunderland Water District system, in which event system
design shall be as specified by the district, evidenced by certification
from the district that it approves the design and will permit connection.
B.
Where connection to the public system is not feasible, a subdivision
plan shall be approved only upon presentation of evidence satisfactory
to the Board, upon advice of the Board of Health, that adequate and
suitable groundwater is available and upon evidence satisfactory to
the Board, upon advice of the Fire Chief, that adequate provisions
for firefighting have been made.
A.
Open spaces. Before approval of a plan, the Board may require that
an area be reserved for a possible park or parks and, by appropriate
endorsement on the plan, require that no building be erected upon
such reserved area for a period of three (3) years without the Board's
approval. Such reservation shall be made where particular natural
features, abutting public land or the potential neighborhood need
for recreation space make later public acquisition appear desirable,
but in no event shall required reserved areas exceed five percent
(5%) of the total area of the subdivision, unless so required by zoning
or other regulations.
B.
Protection of natural features. Due regard shall be shown for all
natural features, such as healthy large trees (twelve [12] inches
or greater diameter breast height), watercourses, scenic points, historic
stone walls, historic spots and similar community assets. These features
shall all be shown on the plans, and the designer must document how
the project avoids, minimizes, and mitigates (in that order) impacts
to these resources.
C.
Written approvals. No definitive plan will be approved unless the
developer submits written certification of approval of the design
by all utilities which are to provide services within the subdivision.
D.
Underground wiring. All wiring, cables and other appurtenances of
electric power, telephone and fire alarm systems shall be placed underground
within the limits of the street right-of-way, except where such underground
installation would, in the judgment of the Planning Board, cause undue
hardship by reason of topography, subsoil conditions or other site
peculiarities or by reason of the existing development pattern. Electric
power cables shall be not less than thirty (30) inches below the finished
grade.
E.
Flood hazard avoidance. Any subdivision located in any part within
the Flood Hazard District as shown on the Flood Insurance Maps issued
by the Federal Insurance Administration (on file with the Planning
Board, Building Inspector and Town Clerk) shall comply with the following:
(1)
Street profile design, drainage design, and open space preservation
shall be consistent with the need to minimize flood damage within
the flood-prone areas.
(2)
All public utilities and facilities, such as sewer, gas, electrical
and water systems, shall be located and constructed to minimize or
eliminate flood damage.
(3)
Adequate drainage systems shall be provided to reduce exposure to
flood hazards.
