Editor's Note: This local law also repealed former Article XI, Street Specifications, as amended. For current provisions, see Article X of this chapter and Ch. 116, Art. III. In addition, this local law also repealed former Article XII, Other Public Improvements, and Article XIII, Miscellaneous Provisions. For current provisions, see Article XI and Article XII, respectively.
Removal of spring and surface water. All subdivisions
shall be related to the drainage pattern affecting the areas involved,
with proper provision to be made for adequate storm drainage facilities.
The subdivider may be required by the Planning Board to carry away
by pipe or open ditch any spring or surface water that may exist either
previous to or as a result of the subdivision. Such drainage facilities
shall be located in the street right-of-way, where feasible, or in
perpetual unobstructed easements of appropriate width. A culvert or
other drainage facility shall, in each case, be of adequate size to
accommodate the potential runoff from the entire upstream drainage
area, whether inside or outside the subdivision area. The design and
size of this facility shall be subject to the approval of the Town
Engineer.
Drainage structure to accommodate potential development upstream. A culvert or other drainage facility shall, in each case, be large enough to accommodate potential runoff from its entire upstream drainage area, not only the anticipated discharge from the property being subdivided but also the anticipated runoff that will occur when property at a higher elevation in the drainage basin is developed. The Town Engineer shall approve the design and size of the facility based on anticipated runoff from the following storm frequencies under conditions of total potential development permitted by Chapter 150, Zoning, in the watershed:
For watersheds with drainage areas larger than one
square mile, all structures should be designed to carry peak runoff
for a one-hundred-year storm. The only acceptable method for calculating
anticipated runoff shall be computed by the soil cover complex method
as utilized by the Soil Conservation Service of the United States
Department of Agriculture.
Responsibility for drainage downstream. The subdivider's
engineer shall study and submit a written report of the effect of
each subdivision on the existing downstream drainage facilities outside
the area of the subdivision. This study shall be reviewed by the Town
Engineer and the Orange County Soil and Water Conservation District.
Where it is anticipated that the additional runoff incident to the
development of the subdivision will overload an existing downstream
drainage facility during a fifty-year storm, provision for the storage
of the increased runoff must be made by the developer. (See Appendix
B, Stormwater Management, found in the Town Soil Report in the Town
offices.)
Land subject to flooding. Land subject to periodic or occasional flooding or land deemed by the Planning Board to be uninhabitable shall not be platted for residential occupancy nor for such other uses as may increase danger to health, life or property or aggravate the flood hazard, but such land within the plat shall be set aside for park purposes in addition to that area which is required by Chapter 150, Zoning.
Easements. Where a subdivision is traversed by a watercourse,
drainageway, channel or stream, there shall be provided a stormwater
easement or drainage right-of-way conforming substantially with the
lines of such watercourse and such further width or construction,
or both, as the Town Engineer may deem adequate to the purpose, but
in no case fewer than 30 feet in width and of such width as to encompass
the flood of record, plus three feet in elevation. Drainage easements
shall be carried from the road to a natural watercourse or to other
drainage facilities. When a proposed drainage system will carry water
across private land outside the subdivision, appropriate rights must
be secured and indicated on the plat.
House and lot drainage. Drainage of individual lots
and dwellings, including footing drains, to assure proper runoff from
roofs, driveways and paved surfaces, and ensure positive drainage
away from houses, shall be required for Planning Board approval. The
installation of such facilities shall be required prior to the issuance
of a certificate of occupancy.
The drainage system and/or culverts shall be designed
in accordance with established engineering principles approved by
the Town Engineer. Stormwater management facilities for water quality
and control shall be designed in conformance with New York State Department
of Environmental Conservation (NYSDEC) stormwater management regulations.
The minimum grade of any drainage pipe or culvert shall not be less
than 0.05%. No culvert shall be smaller than 18 inches in diameter
except by approval of the Town Engineer. Such drainage shall be installed
where natural watercourses cross the highways or at locations which
warrant drainage. The width of the trench in which the pipe is placed
shall be sufficient to permit thorough tamping of the backfill under
the haunches and around the pipe. In no case shall the top of any
drainage pipe be less than 18 inches below the finished grade of the
pavement. Where soft, spongy or unsuitable soil is encountered or
where rocks, boulders or ledges are present, such shall be removed
and replaced with suitable materials and in a manner as directed by
the Town Engineer. The pipe shall be laid to true line and grade on
the prepared bed of the trench. The installation shall be in accordance
with the standard practice. The backfilling of the trench shall be
in accordance with good engineering procedure and as directed by the
Town Engineer.
All high-density polyethylene pipe and reinforced
concrete pipe shall conform to the items covering such in the latest
New York State Department of Transportation specifications.
Drainage pipe of culverts shall be installed to carry
the present requirements of the subdivision as well as that which
may reasonably be anticipated from future construction, both from
within the subdivision and from adjoining properties which normally
drain across the area of the proposed development.
The discharge of established natural watercourses
and stormwater in open ditches shall be permitted only after specific
approval by the Planning Board. If, in its opinion, public health
or safety is jeopardized or there is danger of erosion, approval shall
be denied. In such case, pipe of the proper kind and size shall be
installed or the required paved sluiceways constructed. It shall be
the responsibility of the developer to set aside areas for the collection
and passage of both natural waters and stormwaters.
Headwalls shall be constructed at the inlet and discharge
end of the culvert pipe. Culverts shall extend beyond the toe of the
embankment or, if carried in easements through or along lots, to a
point of no less than 75 feet beyond the rear of proposed residences.
If, in the opinion of the Planning Board or Town Engineer,
it is necessary to intercept and carry away groundwater to protect
the stability of the roadbed, the subdrainage required by the Planning
Board shall be installed. Perforated pipe having a minimum diameter
of four inches shall be used for such purpose if deemed necessary
by the Town Engineer.
Drain lines shall be placed between the center line
of the road and the gutter line and shall, as far as practical, parallel
the center line of the road.
Drainage structures which are located on state
or county highway rights-of-way shall be approved by the State or
County Highway Engineer's office, and a letter from said office indicating
such approval shall be directed to the Town Planning Board.
Surface drainage in gutters shall be limited
to the equivalent of that flowing from 1.5 impervious acres; however,
where the tributary impervious area exceeds the runoff from one impervious
acre, a double-inlet catch basin shall be used.
Planned use of natural and other open drainage
lines shall be based on an investigation and a written report to the
Planning Board as to the downstream conditions anticipated as a result
of such use.
All open drainage lines (watercourses and ditches)
shall be protected by easements guaranteeing to the Town the right
of access and power to improve the channels, as well as prohibiting
structural or terrain encroachments within the easement except on
approval by the Town Engineer. Such easements shall have a minimum
width of 30 feet.
Inconsistency. Where the technical provisions of § 120-68 and this section are in conflict or disagreement with provisions of other ordinances, specifications or regulations applicable to the subdivision, then the most recently adopted provision shall be utilized unless specifically indicated otherwise by the Planning Board.