A.
A hydraulic design report prepared by a licensed professional
engineer containing design information for all highway drainage structures,
storm sewers and channels must be submitted to the Town Engineer and
the 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 method
used to determine 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 the plans
and profile to properly construct all the required drainage facilities.
Type and size of culvert, end treatments of inlets and outlets, the
gauge of metal pipe or class of concrete pipe, invert elevation each
inlet and outlet, ditch and channel section, gutters, channel protection
and alignment of ditches are some of the information required on the
plan and profile.
A.
The developer shall dedicate to the Town by recordable
instrument all easements as shown on the plans.
B.
All drainage easements must have a minimum width of
30 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 easements. 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.
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 ADS with a minimum diameter of 12 inches.
B.
Round corrugated metal pipe and pipe arches, fully
bituminous coated, and end sections shall conform to Section 707-02
of the current Standard Specifications of the New York State Department
of Transportation, with the following exceptions:
(1)
All collars or connecting bands shall be 12 inches
wide and shall be furnished with bolts six inches long.
(2)
Round corrugated aluminum pipe, pipe arches and end
sections shall conform to Section 707-13 of the current Standard Specifications
of the New York State Department of Transportation.
(3)
Reinforced concrete pipe shall be manufactured with
slip joints or bell and spigot joints.
(4)
Each piece of reinforced concrete pipe shall be marked
with the specification number and the date of manufacture.
(5)
Reinforced concrete pipe shall be sealed with flexible
watertight elastomeric gaskets and 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 with the sealant manufacturer's instructions so that
the joint is completely filled with the sealant.
(6)
Round ADS pipe shall conform to the current Standard
Specifications of the New York State Department of Transportation.
(7)
All collars or connecting bands shall be furnished
with plastic ties and installed in accordance with the manufacturer's
recommendations.
(8)
Corrugated metal or ADS pipe and pipe arch connections
for making field joints shall consist of corrugated bands so constructed
as to lap on equal portions of each culvert section to be connected.
(9)
Height of the fill and pipe classes shall be designed
to meet the minimum requirements of H-20 highway loading, which is
equivalent to a truck with two loaded axles carrying 16 tons of load
each.
A.
Whenever a drain 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.
C.
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.
A.
Where underdrains are required, they shall be designed
by a professional engineer and approved by the Superintendent of Highways
and the Town Engineer.
B.
Underdrains may be perforated metal or ADS and placed
in trenches and surrounded by material which is both pervious to water
and capable of protecting the pipe from infiltration by the surrounding
soil. (See Figure 5.[1])
[1]
Editor's Note: Figure 5 is included at the end of this chapter.
Specifications and drawings on Figures 7, 7A,
7B show the minimum acceptable construction for typical catch basins
and curb inlets.[1] Whenever, in the opinion of the Town Highway Superintendent,
ground conditions or other circumstances require larger or heavier
materials and additional materials, reinforcing or other modifications
and improvements in design and construction shall be made as directed
by the Town Highway Superintendent at any time prior to paving.
A.
Location. Catch basins shall be located 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 ponding. At no time shall catch basins be spaced farther
apart than 300 feet on slopes up to 6% and 250 feet on slopes over
6% in steepness.
B.
Construction. All construction and materials shall
comply with Section 604 of the current Standard Specification of the
State of New York Department of Transportation.
C.
Installation of pipes.
(1)
Openings in catch basins around all pipes entering
and leaving the basin shall be cut to fit the contours of the pipes
as closely as possible. Remaining intercises 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 surface of the catch basin
walls and shall project outside a sufficient distance to allow for
proper connection with adjoining pipe section.
(2)
When the diameter of the effluent pipe is greater
than that of the 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
or smaller than the 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. In no case shall the top of any influent pipe
be more than five feet above the invert of the effluent pipe.
D.
Curb inlets.
(1)
Wherever required, catch basins shall be capped with
inlets having a minimum frame opening of 30 inches by 30 inches or
a type as designated by the Town Superintendent of Highways.
(2)
Curb-type inlets shall be installed so that the top
of the grating shall be no more than one inch below the finished grade
of the wearing surface, and the pavement shall be sloped toward the
inlet as shown in Figure 7B.[2] Catch basin covers and cast iron curb boxes shall conform
to the current Standard Specifications of the State of New York Department
of Transportation, Division of Construction, and be designed to carry
H-20 highway loading. All catch basins shall be square unless otherwise
approved by the Town Superintendent of Highways.
[2]
Editor's Note: Figure 7B is included at the end of this chapter.
E.
Steps for catch basins. Catch basins having a depth
greater than 48 inches from the finished surface to the top of the
concrete base shall be provided with steps. The steps shall extend
4 1/2 inches inside the wall of the catch basin. The top step
shall not be more than 18 inches below the finished surface. Intermediate
steps shall be no more than 18 inches apart. Reinforced plastic steps
meeting Section 725-02 of the Standard Specifications, State of New
York Department of Transportation, Construction Division, may be used.
[1]
Editor's Note: These figures are included
at the end of this chapter.
A.
With the approval of the Town Highway 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, hewn quarry stones as nearly cubical in form as is practical,
placed upon a slope not steeper than 1:2 and so laid that the weight
of the large stones is carried by the soil and not by the adjacent
stones. All stones shall weigh 50 to 150 pounds each, and at least
60% of them shall weigh more than 100 pounds each.
D.
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.