All applications for subdivision and site plan shall be reviewed
for consistency with these standards. Waivers or modifications of
these standards may be granted upon a finding by the Planning Board
and/or the Board of Trustees that the modification of the standard
does not compromise the interest of the public health, safety or general
welfare, and would not compromise fulfilling the purposes of this
chapter, and would not be inappropriate to the subject site plan or
subdivision.
A.
Street layout and design.
(1)
Street rights-of-way shall be measured from lot line to lot line.
The minimum width for the right-of-way of a new street shall be 50
feet, unless reduced by the Board of Trustees and/or the Planning
Board. The continuation of an existing street shall be at the same
width as the existing street unless a different width is required
by the Planning Board.
(2)
Where a development adjoins or includes existing streets that do
not conform to the width of 50 feet and it is determined by the Board
of Trustees and/or Planning Board that a future widening of the existing
streets may be appropriate, the new streets shall be designed with
a right-of-way width to accommodate the future widening.
(3)
The layout of new streets shall favor connectivity with the existing
street network for vehicles, providing through traffic where practicable.
(4)
Local streets shall generally be designed such that grades do not
exceed 10%. No street shall have a grade less than 1%. Maximum grades
within 100 feet of intersections shall generally be 4%. The cross
section of the paved surface from the center line to the curbline
or edge of paving shall not exceed a three-percent slope.
(5)
Intersecting street center lines shall generally not be less than
75°. The distance between intersecting streets shall generally
have a minimum offset of 125 feet from closest curb to closest curb.
Approaches to all intersections shall generally follow a straight
line for at least 100 feet measured along the curb. No more than two
street center lines shall meet or intersect at any one point, unless
the intersection is designed as a roundabout or existing site conditions
dictate. Intersections shall be rounded at the curbline, with a curbline
radius based on the street with the largest radius: principal arterials
at 30 feet; minor arterials at 25 feet; and collector and local streets
at 15 to 20 feet.
(6)
Dead-end or cul-de-sac streets longer than 250 feet shall provide
a circular turnaround at the end with a radius of generally not less
than 40 feet for the paved width and 50 feet for the right-of-way
width, and tangent whenever possible to the right side of the road.
Dead-end or cul-de-sac streets 250 feet long or less shall have a
T- or Y-shaped turnabout 60 feet wide as an alternative to a circular
turnabout. If a cul-de-sac street is of a temporary nature, a similar
turnaround shall be provided and provisions made for future extensions
of the street and reversion of the excess right-of-way to the adjoining
properties.
(7)
Dead-end or cul-de-sac streets longer than 400 feet shall generally
have a minimum paved width of 30 feet and shall provide a mountable
curb on both sides of paving. A clear passage of five feet in the
right-of-way shall be maintained outside of both curbs.
(8)
Sidewalks shall generally be provided to enhance pedestrian connectivity
throughout the Village. Where dead-end streets are permitted, a walking
path from the dead end to the other streets and to established walking
trails shall be provided where practicable to facilitate pedestrian
connectivity.
B.
Street names. No street shall have a name which duplicates or nearly
duplicates in spelling or phonetic sound the name of an existing street
so as to be confused therewith. The continuation of an existing street
within the Village shall have the same name. The names of new streets
shall be approved by the Planning Board.
C.
Street construction. Streets shall be constructed in accordance with
the following standards and specifications. Roadways including subgrade,
subbase, base courses and pavements shall be constructed in accordance
with the latest New York State Code, New York State Department of
Transportation (NYSDOT) Standards and Village Standards, which shall
be maintained by the Superintendent of the Department of Public Works.
All subsurface utilities, including service connections to each lot
(terminating at least two feet beyond any sidewalk or curbline, where
sidewalks are not anticipated), and all storm drains shall be installed
prior to the construction of final pavement surfaces. Best practices
should be followed in both the design and materials utilized in order
to ensure long-term durability and minimal maintenance costs.
(1)
All developments shall be served by paved streets.
(2)
The pavement design shall be the responsibility of the developer
and shall be based upon traffic loading projections and field sampling
and laboratory analysis of the subgrade soils in the proposed streets.
The design shall follow current recommendations of the Asphalt Institute,
the Portland Cement Concrete Association or such other generally recognized
standards as may be acceptable to the Superintendent of the Department
of Public Works. Pavement shall be of one type throughout the development
and be either bituminous concrete flexible pavement or portland cement
concrete rigid pavement, except that, where existing concrete roadways
are being widened, the widened pavement shall be portland cement concrete
and the remaining pavement in the development may be either bituminous
or cement.
(a)
Rigid portland cement paving shall be expansion-joint-type paving
utilizing Type A expansion joints (any alternate type joints shall
be approved by the Superintendent of the Department of Public Works),
shall be reinforced, constructed with Class B air-entrained concrete
and shall have a minimum thickness of 6.5 inches.
(b)
Flexible bituminous concrete pavements shall have an equivalent
structural depth of at least 10 inches with a wearing surface of not
less than two inches of compacted pavement, Type FABC-1, a compacted
bituminous stabilized base course of not less than 25 inches, and
a dense graded aggregate base course to provide the remaining depth.
Bituminous stabilized base may be substituted for aggregate base on
a ratio of one part stabilized base to three parts aggregate base.
(3)
Where subbase conditions are wet, springy or of such nature that
surfacing would be inadvisable without first treating the subbase,
these areas shall be excavated to a depth of at least 12 inches below
the proposed subgrade and filled with a suitable subbase material,
such as sand, gravel or stone, as determined by the Superintendent
of the Department of Public Works. Where required by the Superintendent,
a system of Type F underdrains shall be constructed beneath the surface
of the paving and connected to a suitable drain. After the subbase
material has been properly placed and compacted, the surfacing material
shall be applied if the Superintendent of the Department of Public
Works determines that the subbase is stable.
(4)
Subbase and/or aggregate base courses.
(a)
Portland cement pavements shall be constructed with a minimum
of six inches of a granular-type subbase Type 4, Class E. Any subbase
course of aggregate base course shall have a minimum thickness of
four inches.
(5)
Bituminous base courses.
(a)
Bituminous base courses for use with bituminous concrete pavements
shall consist of plant-mixed bituminous stabilized base course (stone
mix or gravel mix) laid in a single lift, maximum thickness not exceeding
four inches.
(b)
Prior to placement of any bituminous base course, the finished
surface of any underlying subbase or aggregate base shall receive
a prime coat.
(6)
Bituminous pavements. Bituminous pavements shall consist of a bituminous
concrete surface course — fine aggregate bituminous concrete
mixed with asphalt. The bituminous pavement wearing surface shall
generally not be installed until just prior to the time the streets
are prepared for final acceptance. Prior to the installation of a
bituminous concrete surface, the bituminous base course shall be inspected
by the Superintendent of the Department of Public Works or his designee.
Any areas of the base course in need of repair shall be removed and
replaced at the discretion of the Superintendent of the Department
of Public Works. If the Superintendent directs, a leveling course
of FABC material shall be placed on any uneven or below grade base
courses prior to the placement of finished pavement. Pavement surfaces
shall be placed only with permission of the Superintendent of the
Department of Public Works.
(7)
Alternate pavement types. If alternate pavement types are proposed
either for decorative purposes, physical restrictions, existing conditions
or shortages in certain construction materials, a detail of the type
and/or location of alternate pavement types shall be submitted for
approval. Approval shall be based upon the equipment, materials and
methods proposed for use and the Superintendent of the Department
of Public Work's inspection, testing and approval of a section of
such pavement. If the Superintendent of the Department of Public Works
does not approve the sample section of pavement, the developer shall
replace it with permitted pavement.
Streetlighting standards of a type and number approved by the
Planning Board shall be installed at street intersections and elsewhere
if deemed necessary by the Planning Board.
Street signs shall be of a type, design and material approved
by the Planning Board. There shall be at least two street signs furnished
at each four-way intersection and one street sign at each T-intersection.
All signs shall be installed free of visual obstruction.
A.
Unless waived by the Planning Board, concrete curb shall be installed
along all streets and along all edges of pavement within a site. The
standard curbs shall comply with the standards as determined by the
Superintendent of the Department of Public Works.
B.
Barrier-free curb ramps shall be constructed in accordance with the
Design Standards for Curb Ramps for the physically handicapped as
established by the American Disabilities Act (ADA), and as instructed
by the Superintendent of the Department of Public Works.
C.
Where curbs are waived or where alternate curbs are allowed, such
as granite block or rolled concrete curb, an appropriate method of
stabilizing the edge of paving, controlling erosion and managing stormwater
shall be incorporated into the design.
D.
Special consideration shall be given to curb and catch basin design,
placement, and selection to facilitate pedestrian and bicycle traffic.
A.
All streets shall be provided with catch basins and pipes where the
same may be necessary for proper surface drainage. The requirements
of this section may not be satisfied by the construction of dry wells.
The system shall be adequate to carry off or store the stormwater
and natural drainage water which originates within the subdivision
boundaries and that which originates beyond the subdivision boundaries
and passes through the subdivision, calculated on the basis of maximum
development as permitted under the provisions of this chapter. No
stormwater runoff or natural drainage water shall be so diverted as
to overload existing drainage on other lands without proper and approved
provisions being made for taking care of these conditions.
B.
The time of concentration used in computing stormwater runoff shall
be the equivalent of the time required for water falling at the most
remote point of the drainage area to reach the point in the drainage
system under construction.
C.
Computations of the rate of flow at any given location shall be based
on the Rational Formula:
|
Q = CIA
|
|
Where:
| ||||
|---|---|---|---|---|
|
Q
|
=
|
Flow in cubic feet per second.
| ||
|
C
|
=
|
Runoff factor.
| ||
|
I
|
=
|
Intensity of rainfall in inches per hour.
| ||
|
A
|
=
|
Watershed area in acres.
| ||
D.
In setting the value of the runoff coefficient C, consideration shall
be given to the physical features of the drainage basin and the best
available data on the future density of development of the drainage
basin. In no case shall C be less than 0.40 after development.
E.
The intensity (I) should be based on the following:
(1)
Ten-year-storm criteria for low points with a relief swale.
(2)
Twenty-five-year-storm criteria for flow carried in pipes.
(3)
One-hundred-year-storm criteria for all culvert designs.
(4)
The Rainfall Intensity = Duration = Frequency Curves, published by
the United States Department of Commerce, Weather Bureau, shall be
used in the above computation.
F.
Where any development is traversed by a watercourse or where a new
swale or piped system is installed, a drainage right-of-way easement
shall be dedicated to the Village. An easement with a minimum width
of 15 feet beyond the bank top on at least one side of a watercourse
shall be provided for practical access.
G.
Stormwater designs shall result in stormwater leaving the property at the same rate that existed prior to the development. All measures shall comply with Village Code Chapter 262, Stormwater Management and Erosion and Sediment Control Regulations, as amended from time to time. Grading shall direct drainage away from all buildings, prevent the collection of water in pools and avoid the concentration of stormwater from one lot to another.
Drainage and utility easements shall be located along rear or
side yard property lines where possible, shall not be less than 15
feet wide, shall be dimensioned on the plat, shall provide for maintenance
access, shall prohibit plantings or construction and shall be identified
as follows: "Drainage/utility easement granted to the Village of Dobbs
Ferry as provided for in the Zoning and Development Regulations Ordinance."
Provision shall be made for fire hydrants along streets or on
the walls of nonresidential structures, as approved by the Dobbs Ferry
Fire Department or the Superintendent of the Department of Public
Works. The midpoint of all lots served by a central water supply shall
be within 500 feet of a functioning fire hydrant. Hydrants shall have
fire hose threads conforming to the fire-fighting equipment, with
no less than two two-and-five-tenths-inch hose connections and one
four-and-five-tenths-inch pumper nozzle. Hydrants shall be set plumb,
with nozzles 18 inches above finished grade.
Sewers shall be installed pursuant to Village Code Chapter 256, Sewers, as amended from time to time.
Connections to the public water supply shall be installed pursuant
to the specifications promulgated by the Superintendent of Public
Works.
