Culverts shall be installed to pass water collected in the ditches,
or flowing in a natural watercourse, beneath the street. Headwater
depths shall be considered in culvert design. Riprap shall be installed
upstream and downstream of culverts as required to control erosion.
Energy dissipators shall be constructed where necessary.
Culverts under streets shall extend from toe of slope to toe of slope
and shall be set with a minimum of two-foot cover over the top of
the pipe unless specifically waived by the town's engineer or
Town Highway Superintendent.
Culverts shall also be installed beneath driveways and access roads
to carry water flowing in the side ditches. Culverts in side ditches
shall be limited to 30 feet in length with a minimum of 20 feet in
length.
Culverts shall have a minimum diameter of 12 inches and shall be
laid on a minimum of 0.5%. In general, the grade line shall coincide
with the existing stream bed or ditch grade.
All culverts shall utilize pipe and sections at each end when hydraulically
feasible. Poured concrete headwalls shall be used where the use of
pipe end sections is not feasible or where headwall construction will
provide a more efficient design. Headwalls shall be constructed to
encompass the entire opening.
Reinforced concrete pipe end sections shall be precast units, and
corrugated steel pipe end sections shall be galvanized steel. All
end sections shall conform to the standards of the New York State
Department of Transportation.
On all pipe end sections 24 inches or over, a twelve-inch minimum
thick poured concrete cutoff wall shall be constructed a minimum of
24 inches below the end section for the full width of the flared end.
Concrete headwalls for culverts shall be constructed of poured concrete
extending at least 12 inches above and 24 inches below the pipe. Concrete
headwalls shall be at least 12 inches thick and as wide as the top
of the ditch, but not less than three pipe diameters wide.
Headwalls proposed to be constructed of materials other than concrete
shall not be constructed without prior written approval of the Town
Highway Superintendent.
All culverts crossing a street without curb and gutter where guide
rail is not utilized shall be marked at each end by an eighteen-by-eighteen-inch
yellow reflectorized hazard marker set at the edge of the shoulder
and mounted on a galvanized steel delineator post, all in conformance
with the New York State Manual of Uniform Traffic Control Devices.