A.
A hydraulic design report prepared by a licensed engineer,
containing design information for all highway drainage structures,
storm sewers and channels, must be submitted to the Town Engineer
and Town Superintendent of Highways. This report should contain the
basic design data required to arrive at each drainage structure size,
such as design frequency, flow rate, grade, velocity, area and the
method used determining the waterway size. A consideration should
also be given to anticipated, if any, future development and any urbanization
of the area.
B.
There should be enough information shown on plans
and profiles to properly construct all the required drainage facilities.
The type and size of culverts, end treatments of inlets and outlets,
the gauge of metal pipe or class of concrete pipe, invert elevation
of inlets and outlets, ditch and channel sections, gutters, channel
protection and alignment of ditches are some of the information required
on plans and profiles.
A.
The developer shall dedicate to the Town by recordable
instrument all easements as shown on the plat.
B.
All drainage easements must have a minimum width of
35 feet and shall include the right to enter upon said property for
the purposes of installing, maintaining and repairing the ditches
and pipes as placed in such easement. It is the policy of the Town
that all storm drainage be enclosed in drainage pipe and all easements
shall contain a provision providing for the right to install underground
pipes and to discharge stormwater therein. The developer shall also
install in said easements pipe of a size sufficient to provide for
present and future runoff, with the pipe being centered 10 feet from
one side of said easement.
C.
Where it is proposed that stormwater be drained from
the highway or from other lands of the developer to the perimeter
of the developer's property, easements shall be provided in recordable
form and free and clear of all liens from the adjoining owners permitting
the discharge of stormwater drainage onto such adjoining lands.
D.
The developer shall provide an attorney's certificate
of title indicating that the above-mentioned easements and rights
to discharge surface water are free and clear of all liens.
A.
Storm drain and culvert pipe may be corrugated metal,
reinforced concrete or smooth interior corrugated polyethylene (ADS-N)
pipe type, or other pipes approved by the Superintendent of Highways,
with a minimum diameter of 15 inches.
B.
Round corrugated steel pipe, pipe arches and end sections,
fully bituminous-coated, shall conform to Section 707-02 of the current
New York State Department of Transportation Standard Specifications,
with the exceptions that all collars or connecting bands shall be
12 inches wide and shall be furnished with bolts six inches long.
C.
Round corrugated aluminum pipe, pipe arches and end
sections shall conform to Section 707-13 of the current New York State
Department of Transportation Standard Specifications,
D.
Reinforced concrete pipe shall conform to Sections
706-02 and 706-10, respectively, of the current New York State Department
of Transportation Standard Specifications.
E.
All reinforced concrete pipe shall be manufactured
with slip joints or bell-and-spigot joints.
F.
Each piece of reinforced concrete pipe shall be marked
with the specification number and the date of manufacture.
G.
Reinforced concrete pipe shall be sealed with flexible
watertight elastomeric gaskets, approved bituminous sealers or plastic
sealers. Bituminous or plastic sealants shall be applied at the time
the pipe is being laid to line and grade. Such sealants shall be installed
in accordance with the sealant manufacturer's instruction so that
the joint is completely filled with the sealant.
H.
Corrugated metal pipe and pipe arch connections for
field joints shall consist of corrugated bands so constructed as to
lap on equal portions of each culvert section to be connected.
I.
Round corrugated steel pipe, pipe arches and end sections
shall be either fully aluminum coated (Aluminized Type 11) or fully
polymeric coated inside conforming to current American Association
of State Highway Officials specifications.
J.
Smooth interior corrugated polyethylene pipe shall
conform to the requirements of AASHTO M294. The pipe must also exceed
the minimum engineering property values as specified in Section 18
of the American Association of State Highway Officials Bridge Design
Manual.
K.
Polyethylene pipe shall be installed in a minimum of six inches of suitable material as defined in § 79-16. Proper compaction must be achieved. The remainder of the ditch is to be filled with suitable material not to exceed six inches in diameter.
L.
The height of the fill and pipe classes shall be designed
to meet the minimum requirements of H-20 highway loading.
Whenever a drain pipe begins or ends in an open
ditch, pond or stream, inlet and outlet ends shall be designed to
protect embankments and channels and to preserve the hydraulic efficiency
of the pipe.
B.
Prefabricated end sections shall be of similar material
and construction to the pipe. End sections shall be connected to the
pipe in the same manner as pipe sections are connected.
C.
Whenever a drain pipe begins or ends in an open ditch,
pond or stream, the inlet and outlet ends shall be designed to deny
access to small children, animals, etc., by the placement of a childproof
hinge-type grate on the end section. The locking system on the hinge
shall consist of a nut-and-bolt method. (See Figure 7c.[4])
[4]
Editor's Note: Said figure is on file in the
Town Clerk's office.
B.
Underdrains must be sloped to an outlet, such as a
drainage channel or a closed drainage system, and shall be placed
at a minimum depth of 24 inches to the bottom of the pipe.
C.
Figures 8b and 11 of Appendix B 14[2] show the installation of underdrain for the purpose of
draining of pavement sections. These figures may be modified to apply
to specific conditions. However, criteria described below should be
considered.
[2]
Editor's Note: Said figures are on file in
the Town Clerk's office.
D.
The underdrains should be placed at the interface
of the pavement and shoulder or curb and should intercept the water
from the highest water-bearing layer of the pavement section.
A.
Specifications and drawings on Figures 9A, 9B, 9C
and 10[1] show the minimum acceptable construction for typical catch
basins, curb inlets and manholes. The Superintendent and Town Engineer
shall have authority to require the use of larger or heavier materials,
additional materials, reinforcing or other modifications and improvements
in design and construction over those set forth in the figures when
they determine that such modifications would provide improved drainage
and are required by site conditions.
[1]
Editor's Note: Said figures are on file in
the Town Clerk's office.
B.
Location. Catch basins shall be constructed at all
points of change of slope or alignment and at all junction points.
Catch basins shall be located in the lows of sag vertical curves as
necessary to prevent excess ponding. At no time shall catch basins
be spaced further apart than 400 feet on slopes less than 3%, 300
feet on slopes from 3% to 6% and 250 feet on slopes steeper than 6%.
C.
Material, excavation and construction.
(1)
Figure 9A[2] shows the minimum acceptable construction for typical
precast catch basins. Holes for catch basins shall be excavated to
a depth of 35 inches below the designated elevation of the invert
of the effluent pipe. Crushed stone or run-of-bank gravel to a uniform
depth of nine inches shall be leveled and compacted over the entire
area under the base.
[2]
Editor's Note: Said figure is on file in the
Town Clerk's office.
(2)
Catch basins shall be precast, reinforced concrete
sections conforming to ASTM C-478 Specification, current edition,
and shall have a minimum twenty-eight-day compressive strength of
4,000 pounds per square inch. Catch basin structures shall also meet
the following design criteria:
(a)
The walls and base of the base unit shall be
of one-piece construction.
(b)
Base units shall be provided with knockouts,
commensurate in size and number with the pipes so indicated for installation
as shown on the plans. Knockouts shall be constructed to permit the
inverts to be not less than that shown on Figure 9A.[3]
[3]
Editor's Note: Said figure is on file in the
Town Clerk's office.
(c)
Base units and riser sections shall not be greater
than three feet in height.
(d)
The interior and exterior of catch basins shall
be parged at all seams and joints.
(3)
Inside dimensions of the catch basin shall remain
constant from top to bottom and shall match the frame opening of the
inlet to be used.
(4)
All construction and materials shall comply with Section
604 of the current New York State Department of Transportation Standard
Specifications.
D.
Installation of pipes.
(1)
Concrete blocks around all pipes entering or leaving
the catch basin shall be cut to fit the contours of the pipes as closely
as possible. Remaining interstices shall be solidly filled with mortar
for the full thickness of the wall. Ends of all pipes shall be cut
off flush with the inside surfaces of the catch basin walls and shall
project outside a sufficient distance to allow for proper connection
with adjoining pipe sections.
(2)
When the diameter of the effluent pipe is greater
than that of an influent pipe, the elevation of the top of the influent
pipe shall be no lower than the elevation of the top of the effluent
pipe.
(3)
When the diameter of the effluent pipe is the same
as or smaller than that of an influent pipe, the elevation of the
invert of the influent pipe shall be no lower than the elevation of
the invert of the effluent pipe.
(4)
In no case shall the top of any influent pipe be more
than five feet above the invert of the effluent pipe.
E.
Curb inlets.
(1)
Catch basins shall be capped with curb inlets having
a minimum frame opening of 30 inches by 48 inches, of a type designated
by the Superintendent.
(3)
Curb inlets shall have, centered in the opening, a
solid horizontal bar to prevent the ingress of small children. This
bar shall be part of the casting or solidly welded in place subsequent
to manufacture.
(4)
Catch basin cast-iron covers and cast-iron curb boxes
shall conform to the current New York State Department of Transportation
Standard Specifications and shall be designed to carry H-20 highway
loading.
F.
Steps for catch basins. Catch basins having a depth
greater than 48 inches from the road surface to the top of the concrete
base shall be provided with steps. Steps shall be of wrought iron
having a minimum diameter of one inch which shall be hot-bent to shape
and hot-dipped galvanized after bending. The steps shall be solidly
set in the masonry at the time of construction and shall extend 4 1/2
inches inside the wall of the catch basin, with a clear length from
the inside wall to the outside of the step of not less than 5 3/4
inches for foot placement. The top step shall be not more than 18
inches below the road surface and thence to the base steps shall be
no more than 12 inches apart. All steps in each section shall be so
aligned as to form a continuous ladder. Steps shall be installed by
the catch basin producer in accordance with the manufacturer's installation
specifications. Reinforced plastic steps meeting Section 725-02 of
the New York State Department of Transportation Standard Specifications
may be used in lieu thereof.
A.
With the approval of the Superintendent and Town Engineer,
open ditches for back lots and side slopes may be used in lieu of
storm drain pipes when the grade of the land traversed is flat or
when it is desirable to drain and dry up the surrounding area.
C.
Riprap, when called for, shall consist of field stone
or rough, unhewn quarry stones as nearly cubical in form as is practicable,
placed upon a slope not steeper than one to two (1:2) and so laid
that the weight of the large stones is carried by the soil and not
by the stones adjacent. All stones shall weigh 50 pounds to 150 pounds
each and at least 60% of them shall weigh more than 100 pounds each.
D.
The largest stones shall be placed first, roughly
arranged and in close contact. The spaces between the larger stones
shall be filled with spalls of suitable size.
E.
Whenever a drain pipe enters an open ditch, the bottom
and sides of the ditch shall be riprapped for a distance of at least
30 feet beyond the end of the pipe.
F.
Paved roadside ditches shall be paved with asphalt
concrete in three-inch thickness.
A.
Detention and retention ponds should not be considered
as the normal way to mitigate downstream drainage impact. They should
only be used in cases where all other options have been investigated
and eliminated and where no other recourse is available. In a case
where a detention or retention pond is required, the following shall
be adhered to. Under no circumstances shall any of the following be
permitted in the stormwater retention/detention ponds:
(1)
Alteration of topography.
(2)
Placing of fill.
(3)
Channel encroachment.
(4)
Placement of any structures, trees or other such physical
objects thereon.
(5)
Grading, excavating or the removal of material.
(6)
Removal or destruction of turf, trees and/or vegetation.
(7)
Causing siltation or deposition of debris or other
similar material.
(8)
Causing or creating any act that would alter the drainageway
located therein.
(9)
Utilizing any portion thereof for any motorized vehicle
for any purposes, including recreational purposes.
(10)
The erection of any improvements or other developments.
B.
In addition, the ponds shall have a minimum one-percent
slope in any direction, and the banks shall be impervious, maximum
two horizontal to one vertical.
C.
In no event shall the Town take ownership, nor accept
responsibility for maintenance, of a detention or retention pond.
