A.
Basic requirement. All subdivisions shall be designed and improvements made by the developer consistent with the requirements of Article IV. Subdivisions shall be designed to be consistent with one of the following subdivision types, as described further in Appendix A, or shall be divided into subareas, each of which is designed to be consistent with one of these types:
(1)
Village. Village subdivisions are appropriate
within or adjacent to densely developed areas, or where a future village
center is proposed. They are intended to continue the pattern of traditional
development. In light of relatively small lots and short frontages,
drainage systems will be closed, and sidewalks and granite curbs will
be installed.
(2)
Gathering. Gathering subdivisions are intermediate
between village and dispersed, such as in the developed portion of
a subdivision having low overall density but clustered lots. Drainage
will usually be closed, but sidewalks will be required only in certain
cases. Curbing, if provided, need not be vertical granite. The road
edge may sometimes be a grass berm.
(3)
Dispersed. Dispersed subdivisions involve large
lots and long frontages, so drainage may normally be open, streets
may be without curbs or berms, and sidewalks are required only in
special circumstances.
B.
General design guidelines. The subdivision plan should
reflect the suggestions of Appendix B,[1] which contains general design guidelines.
[1]
Editor's Note: Appendix B is included at the end of this chapter.
C.
Conformance with Master Plan. The subdivision plan
shall conform insofar as practical to any elements of the Williamstown
Master Plan which have been adopted by the Planning Board in the same
manner as prescribed for amendments to this chapter and which are
made available along with copies of this chapter.
D.
Standards of construction. Standards of construction
not otherwise specified hereunder shall be those of the Williamstown
Department of Public Works Construction Standards or, where that agency
has no standard, the Standard Specifications for Highways and Bridges
of the Massachusetts Department of Public Works (latest edition with
amendments in effect at that time).
E.
Typical cross sections. Design and construction shall
conform to the general configuration shown in the typical cross sections
of Appendix A[2] and to the detailed requirements shown on the Street Cross Sections incorporated into Chapter 113, Road Construction Standards.
[2]
Editor's Note: Appendix A is included at the end of this chapter.
A.
Location.
(1)
All streets in the subdivision shall be located
so that they will provide safe vehicular travel.
(2)
Streets shall be continuous and in alignment
with existing streets as far as is practicable.
(3)
If adjoining property is not subdivided, proper provision for extending streets shall be made, except in the case of developments under minor lane residential development of § 170-3.4.
(4)
Reserved strips of property prohibiting access
to streets or adjoining property will not be permitted.
(7)
Intersections shall provide for block lengths
of between 600 and 1,000 feet, and on collector streets shall be spaced
not less than 600 feet apart.
(8)
The center line of the paved surface shall coincide
as closely as possible with the right-of-way center line. In no case
shall either edge of the paved surface be closer than 10 feet to the
edge of the right-of-way.
B.
Geometric standards. Streets shall be designed to meet the geometric standards of the following table, except where departure is authorized or required for minor lanes under §§ 170-3.4 and 170-4.2H. The Planning Board may impose more demanding requirements, but only where exceptional conditions make that necessary for public safety. "Hillside" applies to streets or street segments where average slopes exceed 15% across the street center line.
Geometric Requirements
| ||||||
---|---|---|---|---|---|---|
Street Type
| ||||||
Requirements
|
Lane/ Minor Lane
|
Minor Street
|
Collector Street
|
Non- residential
| ||
Minimum center- line radius (feet)
| ||||||
Basic
|
125
|
150
|
250
|
250
| ||
Hillside
|
75
|
100
|
150
|
N/A
| ||
Minimum design speed for sight distance (mph)*
| ||||||
All classes
|
20
|
20
|
30
|
30
| ||
Pavement edge radius at corner (feet)
| ||||||
Village type
|
10
|
10
|
20
|
N/A
| ||
Others
|
25
|
25
|
30
|
30
| ||
Minimum right-of- way (feet)
| ||||||
Basic
|
45
|
50
|
60
|
50
| ||
Hillside
|
40
|
45
|
45
|
N/A
| ||
Minimum pavement width (feet)
| ||||||
Basic
|
20
|
24
|
30
|
26
| ||
Hillside
|
18
|
20
|
22
|
N/A
| ||
Maximum center- line grade (%)
| ||||||
Basic
|
12%
|
10%
|
8%
|
10%
| ||
Hillside
|
12%
|
12%
|
10%
|
N/A
| ||
Minimum leveling area length (feet)
|
[See § 170-4.2D(2).]
| |||||
Basic
|
40
|
40
|
40
|
50
| ||
Hillside
|
20
|
20
|
20
|
N/A
| ||
NOTES:
| ||||||
"N/A" indicates a category which is not allowed.
| ||||||
* Design to based on AASHTO standards and, for
intersections, the highest street category involved.
|
C.
Dead-end streets.
(1)
Permissibility. Dead-end streets shall not be
allowed in village subdivisions unless there is no feasible alternative.
Where they are employed, there or elsewhere, dead-end streets shall
provide access to no more than 12 dwelling units potentially allowable
under current zoning and any restrictions proposed, unless, in the
opinion of the Board, serving a greater number is necessitated by
topography or other local conditions, and any concerns over emergency
access in contingencies have been resolved.
(3)
Turnaround.
(a)
Dead-end streets shall be provided at the closed
end with a fourteen-foot wide turning lane providing an outside turning
radius of 40 feet, and a property line diameter of 105 feet, or an
alternative turnaround designed for a vehicle of thirty-foot length,
eight-foot width, and having an outside turning radius of 57 feet.
Standard or teardrop turnarounds shall have vegetated islands, with
plantings selected and placed to preserve safe sight distances.
(b)
Except that for minor lanes, right-of-way property
line diameter may be reduced to 80 feet, outside turning radius to
30 feet, and vegetated islands may be omitted.
D.
Grades.
(1)
Maximum and minimum. Center-line grades of all streets shall be not greater than indicated in the Geometric Standards Table, except where, because of unusual conditions, an increase of not more than 1.0% for distances of not more than 300 feet improves the degree to which the design guidelines of § 170-4.1B are met. Center-line grade shall be not less than 1.0%.
(3)
Vertical curves. Changes in grade exceeding
1% shall be connected by vertical curves of sufficient length to afford
a passing sight distance as specified in the Geometric Standards Table,
unless drainage considerations dictate otherwise for sag vertical
curves.
(4)
Cross-slope. The street surface shall have a
cross slope of 3/8 inch per foot on each side of the center line.
(5)
Wetland relationship. Center-line profiles shall
be at least three feet above the grade of adjacent wetlands.
(6)
Volume balance. Street grades shall be so designed
that the volume of cuts and fills made within the subdivision's rights-of-way
approximately balance, except to offset peat, boulders or other unusable
materials to be removed.
(7)
Grade change limitation. Proposed center-line
grade shall not be more than seven feet above or below the existing
center-line grade.
E.
Street construction. Materials and construction for streets shall comply with Chapter 113, Road Construction Standards, as most recently revised.
F.
Curbs and berms.
(1)
Requirement. Curbs shall be provided on both
sides of all streets in village subdivisions, and curbs or bituminous
berms shall be provided in other subdivisions as follows:
(2)
Materials. Where curb or berm is required, materials shall be as follows, in each case complying with Chapter 113, Road Construction Standards:
(a)
Granite curbing type VA 4: frontage average
under 50 feet per housing unit, or village subdivision.
(b)
Grass berm: Frontage average over 100 feet per
housing unit; curb grade does not exceed 8%; street edge radius is
at least 75 feet; and area drainage characteristics are demonstrated
to the satisfaction of the Planning Board to be suitable for such
berms.
(c)
Six-inch bituminous concrete berm: all other
cases requiring curb or berm.
(3)
Handicapped access. Where sidewalks are constructed, sidewalk ramps shall be provided at each intersection, designed and constructed in compliance with Chapter 113, Road Construction Standards, and the Rules and Regulations of the Architectural Access Board, 521 CMR, whichever is more stringent.
G.
Driveways. All driveways must be paved from the completed
road surface to the lot line with at least three inches of bituminous
concrete unless roads are to be gravel. All driveway slopes must end
at the street right-of-way, then continue forward to the completed
road surface in the same grade as the sidewalk strip and/or shoulder
in order to allow proper drainage of surface water.
H.
Minor lanes. The following shall apply to minor lane residential developments approved under § 170-3.4:
(1)
General. Minor lanes shall be designed with
consideration for the natural contours of the landscape, and shall
provide adequate drainage at all points, while minimizing erosion
both on and beside the road. Depressions shall be filled to a grade
above that of the adjacent roadside and, where possible, natural drainage
measures (i.e., swales and retention ponds) shall be employed rather
than storm sewers and catch basins. Where natural drainage is used,
drainage easements shall be provided to permit maintenance and to
provide for possible water accumulation. Appropriate measures shall
be taken to reduce siltation and to preserve and restore roadside
vegetation.
(2)
Design.
(a)
Reductions from the width of the traveled way required for a lane under § 170-4.2C may be permitted, but in no case shall the width of the traveled way of a minor lane be less than 12 feet, with an additional two feet in width cleared of branches and obstructions. The right-of-way width shall be not less than 33 feet.
(b)
Grades shall not exceed 12%, and center-line radius shall be not less than 75 feet. Where the traveled way is permitted to be narrower than required at § 170-4.2C for a lane and more than 300 feet long, there shall be turnouts allowing vehicles to pass.
(c)
At intersections with paved roads, there shall be a leveling area as provided by § 170-4.2D(2) unless the Planning Board authorizes substitution of a paved apron, subject to DPW approval on a case-by-case basis.
(3)
Construction. Construction of minor lanes shall
conform, at a minimum, to the requirements of Section II.A.1 of the
Williamstown Department of Public Works Construction Standards for
gravel roads which fall under minor lane status.
(4)
Maintenance. Minor lanes are not intended to
be accepted as public ways or to be otherwise maintained by the Town
of Williamstown. Prior to the endorsement of approval on a minor lane
definitive plan, the applicant shall be required to provide assurances
satisfactory to the Planning Board as to the provision for permanent
maintenance of the approved minor lane at no expense to the town.
A.
Design.
(1)
Basic requirement. Storm drains, culverts, swales,
detention basins and related facilities shall be designed to permit
the unimpeded flow of all natural watercourses, to ensure adequate
drainage at all low points along the streets, to control erosion,
to intercept stormwater runoff along streets at intervals reasonably
related to the extent and grade of the areas being drained and to
control the location, rate and quality of stormwater discharge from
the development.
(2)
System Approach. In dispersed-type subdivisions
an "open" drainage approach will normally be appropriate, with roadway
design aimed at removing water from paved surfaces continuously rather
than at infrequent catch basins or spillways, and using swales and
ponding areas in preference to gutters, catch basins and piped stormwater.
In other subdivision types, drainage normally will be a "closed" system,
with stormwater carried in gutters to system inlets. The Planning
Board will consider combinations where applicable, and will consider
other options based on the specifics of the particular development
plan. No closed drainage systems shall be used on unpaved roads.
(3)
Design basis.
(a)
In storm events up to a fifty-year storm, peak
flows in downstream drainage facilities and receiving streams and
sheet runoff onto adjoining properties shall be no higher following
development than prior to development, unless an increase is authorized
by the Planning Board, following consultation with the Conservation
Commission and consideration of the ability of receiving facilities,
wetlands or water bodies to absorb the increase, and the consequences
of providing detention capacity. Drainage systems shall be designed
based on a ten-year frequency storm, except that detention facilities
shall be based on a fifty-year storm, and in a one-hundred-year storm
streets shall be inundated not more than six inches deep, and a building
site on each building lot shall remain uninundated. Drainage design
shall accommodate and account for drainage from foundation drains
and cellar sumps.
(b)
In the Floodplain District, drainage systems
shall be designed to reduce exposure to flood hazards.
B.
Storm drains.
(1)
Catch basin and sewer configuration. Where employed, catch basin and storm sewer systems shall be configured as required by Chapter 113, Road Construction Standards.
(2)
Adjacent property. Proper connections shall
be made with any existing drains in adjacent streets or easements
where they may exist and prove adequate to accommodate the drainage
flow from the subdivision. Subdivision plans indicating piped, channeled
or otherwise altered discharge onto property of others shall be allowed
only if documentation is provided demonstrating authorization from
the property owners involved.
(3)
Subdrains. Subdrains or interceptor drains are
required where necessary to preclude flowage of groundwater threatening
to the integrity of the road surface.
C.
Catch basins and manholes. Catch basins shall be provided
with grates installed. Leaching catch basins will not be allowed.
D.
Detention basins. Where employed, detention basins
shall be designed in compliance with the following:
(1)
Depth and grading. Basin overspill height shall
be not less than one foot above the highest water surface projected
for the design storm, and shall not exceed five feet above bed elevation.
The slope of detention basin walls shall not exceed one foot vertical
in three feet horizontal.
(2)
(3)
Inflow. Inflow pipe invert shall be high enough
that there will not be substantial backwater in the pipe with the
detention basin at maximum depth. The downstream end of the inflow
pipe shall be suitably protected against scour and shall protect the
bed and sides of the basin.
(4)
Outflow. An outflow drain with trash interceptor
shall be provided, with a design assuring that outflow will not exceed
existing flows for any event up to the design storm, and that the
basin will empty in not more than four days in the design storm. Any
outflow pipe shall be not les than six inches in diameter. Outflow
invert shall be not less than 0.50 foot above bed elevation. An overflow
weir protected against erosion shall be provided for accumulations
exceeding those of the design storm.
(5)
Planting. The basin side slopes and bottom shall
be provided with four inches of loam, and seeded.
(6)
Protection. A four-foot fence or wall shall
be constructed around the basin with an eight-foot wide gate for access
(may be double four-foot leaf), with lock, and a key shall be provided
to the Town of Williamstown. However, if the detention facility has
slopes not exceeding one foot vertical to five feet horizontal and
a maximum water depth of not more than 2.5 feet, an alternative barrier,
such as a hedge, may be allowed.
(7)
Maintenance. Maintenance of detention facilities and other off-street drainage elements shall be assured at no expense to the town, as provided at § 170-4.6D(2).
A.
Installation. All elements of sewers, water pipes,
gas lines, telephone, electricity and CATV cable which are to be within
the traveled way shall be installed before roadway base course installation.
B.
Water.
(2)
System responsibility. If connection to a public
water system is proposed but it is determined by the Board that the
above standards will not be met in part or all of the subdivision
for reasons beyond the reasonable responsibility of the developer,
the Board may nevertheless approve the plan subject to a condition
that any lot not adequately served shall not be built upon until service
has been made adequate.
(3)
Standards. Water system design, equipment, materials
and construction shall meet the Construction Standards of the Williamstown
DPW, and Fire District requirements for hydrant location.
(4)
Dead-end mains. Permanent dead-end water mains
shall not normally be allowed. Easements shall be provided where necessary
to allow for extension or looping of mains through subsequent development.
C.
Sewerage.
(1)
Public system. Where street laterals in subdivision
streets could connect by gravity to the town sewerage system, provisions
shall be made for town sewerage to serve all lots which potentially
can be so served. Extension of existing sewerage will be required
at the developer's expense to meet this requirement unless either
the Hoosic Water Quality District denies authorization, or connection
would require greater expenditures for facilities outside the subdivision
and not abutting it than for those within or abutting the subdivision,
including house connections, or would require acquisition of easements
across property of others.
(2)
Design. Sewerage system design and construction
shall comply with the Construction Standards of the Williamstown DPW,
as well as applicable requirements of state and federal law.
D.
Cable utilities.
(1)
Wiring. Underground distribution systems shall
be provided for any and all utility services, including electrical,
telephone and cable television services. Poles and any associated
overhead structures, of a design approved by the Planning Board following
consultation with the Fire District, shall be provided for streetlighting.
(2)
Streetlighting. The quantity, type and location
of lights within a proposed subdivision shall be subject to Planning
Board approval following consultation with the Fire District, and
shall be shown on the Street Plan. Streetlighting shall normally be
installed at each intersection, cul-de-sac or other road hazard. In
village subdivisions light spacing normally shall not exceed 350 feet.
E.
Floodplain District. In the Floodplain District, as established in Chapter 70, Zoning, all public utilities and facilities, such as gas, electrical and water systems, shall be located and constructed to minimize or eliminate flood damage.
F.
Utility lanes. The applicant may propose location
of some or all utilities in service lanes along rear lot lines if
the utility providers involved give written approval to the access
and other provisions being made.
A.
Sidewalks.
(1)
Requirement. Sidewalks shall be provided on
both sides of all streets in village subdivisions. In other subdivision
types, sidewalks shall be provided where doing so is determined by
the Planning Board to be appropriate in order to preserve or connect
with existing sidewalks, to provide safe access to schools or recreation
facilities or where unusual conditions require them for safety.
(2)
Design.
(a)
Sidewalks shall be five feet in width in village subdivisions, constructed of concrete. Elsewhere where required, sidewalks shall be four feet in width, constructed of bituminous concrete, except where the Board determines that potential use warrants a sidewalk five feet in width or construction of concrete. The sidewalk shall be located as indicated on the cross sections of Chapter 113, Road Construction Standards, but variations may be authorized by the Board to minimize disturbance of vegetation or land forms. Sidewalk ramps conforming to the Construction Standards of the Williamstown DPW shall be provided at all intersections of sidewalks and streets, and elsewhere as appropriate.
(b)
Any off-street paths shall provide a clear path
not less than five feet wide and be within rights-of-way not less
than eight feet wide, in both cases unless greater width is required
because of the function of the pathway.
B.
Shoulders. Shoulders shall be provided free of obstructions other than trees approved for preservation by the Board. Width shall be as indicated on the cross sections in Chapter 113, Road Construction Standards.
C.
Slope areas.
(1)
Slope limitations. No slopes resulting from
grading of streets shall exceed one foot vertical to two feet horizontal,
or 3/4 foot vertical to one foot horizontal in ledge. Slope easements
for construction shall be provided where regrading cannot be contained
within street side lines. Any retaining walls proposed must be located
in easements outside of the street right-of-way, with provisions for
private maintenance.
(2)
Stormwater containment. Driveway entrances and
land between the outside of the layout and the traveled way shall
be so graded as to prevent surface water on the street from draining
onto private land except at designated ponding areas or at drainage
easements.
D.
Plantings.
(1)
Clearing. The site of a project shall only be
cleared to the extent necessary for construction or for safe sight
distances. Trees, shrubs and ground cover beyond the limits of construction
should be preserved whenever possible, and so marked in the field
and protected against damage during construction.
(2)
Stream protection. A strip of vegetation 10
or more feet wide shall be preserved along stream banks to stabilize
slopes and protect against erosion.
(3)
Preserved plant materials. Plant materials which
require removal for construction should, when feasible, be salvaged
to be replanted at a later time.
(4)
Ground planting. Unpaved areas within the right-of-way which have been stripped by the construction shall be restored to vegetation, except where stone riprap is necessitated for drainage. That vegetation shall be perennial grasses on at least four inches (after rolling) of topsoil, with methods and materials as specified in Chapter 113, Road Construction Standards. Slopes steeper than 2.5:1, or which do not support turf, shall be planted with vines, ground cover or other low-growing herbaceous or woody plants in addition to grass.
(5)
Street trees. Tree retention or planting shall
provide substantial microclimate protection (shading, wind interruption)
for subdivision streets, except where not doing so is approved in
advance by the Board in order not to obstruct vistas or because of
localized growing conditions. A plan showing location and species
of trees proposed for retention or planting to accomplish that shall
be submitted to the Board for approval before planting. Where street
trees are to be located outside of the right-of-way, an easement shall
be provided, giving the town both authority regarding tree planting,
maintenance and removal, and responsibility regarding tree maintenance.
(6)
Tree stock. Trees to be planted as street trees
shall be well branched, nursery grown stock at least 21/2 inches trunk
diameter at four feet above ground, and shall be free of injury, harmful
insects and diseases. Suitability of species must be approved by the
Planning Board, taking into consideration the recommendations of the
Tree Warden and such published guides as Arnoldia, Volume 39, #3,
May/June 1979, and American Standards for Nursery Stock, American
Association of Nurserymen, 1990, with considerations as outlined in
Appendix C.[1] Planting and maintenance shall follow guidelines of the
American Association of Nurserymen.
[1]
Editor's Note: Appendix C is included at the end of this chapter.
(7)
Existing trees. Existing trees within the right-of-way,
if larger than four inches trunk diameter at four feet above ground
and located outside the shoulders, shall be preserved, unless removal
is authorized by the Planning Board because they are of species unlikely
to survive the environmental change, or are diseased, weak or easily
broken by wind or snow loads when exposed. Trees to be retained shall
be marked in the field, protected as necessary and not have grade
changed over their root areas more than 12 inches.
E.
Street signs. As soon as a street is paved, street
signs conforming to those placed by the town shall be erected at all
street intersections.
F.
Monuments. Monuments shall be installed at all street intersections; at all points of change in direction or of curvature of the streets; at each lot corner along the street; and as necessary to locate any easements to be deeded to the town. Materials and construction shall be as provided in Chapter 113, Road Construction Standards.
A.
Open space.
(1)
Basic requirement. The Planning Board may require
the plan to show a potential park or parks suitably located for recreational
purposes or for providing light and air. The park or parks shall not
be unreasonable in area in relation to the land being subdivided and
to the prospective uses of the land.
(2)
Reservation. The Board may by appropriate endorsement
on the plan require that no building be erected upon such potential
park or parks for a period of not more than three years without its
approval, which provides a period within which the town or a nonprofit
organization has an opportunity to purchase the designated property.
B.
Earth removal. Any area within the subdivision used
for the extraction of gravel or borrow shall be regraded, loamed and
in sod before final release is granted by the Planning Board.
C.
Spoil lots. One or more lots or other designated areas
in each subdivision shall be reserved for disposal of stumps and rock
resulting from the development of that subdivision, unless the applicant
provides a written agreement providing for off-premises disposal at
an approved site. Land within the subdivision intended for such use
shall be so identified on the subdivision plan, and further indicated
on that plan as "not a building lot." Notice that such use has been
authorized by the Board of Health shall be posted on the premises
until disposal is completed, and all requirements of the Board of
Health are complied with, at which point the land shall be restored
to safe and stable slopes and grades, and vegetation shall be restored.
Such restoration shall be included in the items for which bond or
other security is provided, and shall be completed prior to final
release of security.
D.
Maintenance.
(1)
General. The entire area within the right-of-way
shall be properly maintained by the developer or successor organization,
such as a homeowners association, until accepted by the town. Immediately
prior to such acceptance, all catch basins shall be cleaned, streets
swept and the remainder of the right-of-way and any other areas to
be deeded to the town shall be cleaned, mowed or otherwise put in
first-class order. Snow removal and sanding of the streets shall be
the responsibility of the developer or successor organization until
such acceptance.[1] Before sale of any lot, the subdivider shall clean up
any debris thereon caused by construction of public improvements.
(2)
Permanent responsibilities.
(a)
Except for minor lane residential development, whose maintenance is provided for in § 170-4.2H(4), when private maintenance of landscaping within streets or off-road detention facilities or street tree easements are entailed, the applicant shall be required to provide assurances, satisfactory to the Planning Board, as to the provision for permanent maintenance of the improvements at no expense to the town.
(b)
Prior to conveyance of any lots, the applicant
shall enter into an agreement with the town to ensure the continued
operation and maintenance of those elements cited above without expense
to the town.
E.
Easements.
(1)
Utility easements. Easements for utilities shall
be provided where necessary and shall be at least 20 feet wide.
(2)
Drainage easements. Where a subdivision is traversed
by an intermittent watercourse, drainageway, detention area, channel
or stream, there shall be provided a stormwater easement or drainage
right-of-way of adequate width to conform substantially to the lines
of such watercourse, drainageway, detention area, channel or stream
and to provide for construction or other necessary purposes (such
as maintenance).
(3)
Off-site Easements. Drainage easements outside
of the area of the subdivision, but occasioned by it, may be required
of the subdivider.
(4)
Slope easements. Slope easements to provide
for construction shall be provided where cut or fill slopes cannot
be contained within the street right-of-way.
Provisions shall be made for extension of streets
and utilities to adjoining properties, including installation of water
gates and manholes, if necessary, unless the Planning Board determines
that such extension would not serve the public interest. The developer
shall not deny others connection to the water system, sewerage, drainage
or cable utilities, provided that those doing the extension receive
prior approval of the Williamstown DPW and pay all costs of such connection,
and comply with all applicable requirements of the Town of Williamstown.