[HISTORY: Adopted by the Town Board of the
Town of Williamson 11-10-2003 by L.L. No. 3-2003; amended in its entirety 9-12-2017 by L.L. No. 4-2017. Subsequent amendments noted where applicable.]
A.
It is the purpose and intent of this chapter to protect the Town
of Williamson and its residents from the adverse effects of stormwater
runoff caused by the modification of existing drainage systems during
construction, reconstruction, development or improvement on one or
more parcels of land, or by modification for any other purpose.
B.
The adverse effects include but are not limited to the following:
(1)
Increased rate, quantity, velocity of stone drainage, soil movement
or erosion, sediment accumulation and flows caused by but not limited
to:
(a)
A decrease in area of soil able to absorb water, due to construction
or reconstruction of streets, buildings and parking lots.
(b)
Change in volume, velocity and duration of water concentration
caused by altering the steepness, distance and surface roughness.
(c)
The obstruction of stream and channel flow by construction or
reconstruction, backfilling, excavating and refuse disposal.
(d)
The removal of surface vegetation prior to or during construction
and development without proper precautions in place.
As used in this chapter, the following terms have the meanings
indicated:
The activities associated with producing crops or raising
livestock.
A plan, approved by the subdivision of government as required
by law, that covers grading, erosion and sediment control.
Water-bearing rock or soil strata.
The bed or lowest point of a watercourse.
A network of conduits, pipes, culverts and appurtenant structures
constructed to convey the runoff of natural surface waters.
The County of Wayne.
The holding of natural surface water during and following
a rainfall event, or during snow melt conditions, in an area planned
for such use, in such a way that the addition of the detained water
to downstream drainageways or natural watercourses can be achieved
in a controlled manner, usually by means of a throttling facility
such as a culvert or weir structure.
The temporary body of water created by planned detention
which makes use of natural water collection areas, or areas which
tend to collect surface water due to man-made terrain features such
as limited-flow culverts, restricted outlets, etc.
A man-made construction which creates a detention pond by
limiting flow rates away from a natural collection area or which adds
to the detention capacity of such an area.
The actual owner or owners of the land and/or person, firm
or corporation which develops or uses land within the Town in such
a manner that it in any way affects the storm or surface water drainage
characteristics of the property developed or used. The term "developer"
shall include municipal, charitable and educational corporations,
institutions, associations and governmental agencies.
Any improved land use, including residential, commercial,
industrial, institutional or recreational; includes development of
raw land as well as additions or alterations to presently developed
land.
A narrow excavation having steep sides, used to drain or
irrigate property.
The gravitational movement of water from its place of origin
via surface runoff within or outside developed channels or via subsurface
underflow.
The area drained by a watercourse, in this chapter used interchangeably
with "watershed."
A committee appointed by the Town Board.
A permanent and/or temporary right-of-way granted by the
owner to the Town providing unhindered access to the banks and channels
of streams and drainage systems.
A network consisting of any combination or type of open channels
and enclosed artificial facilities and/or retention or detention facilities
employed to convey or control the runoff of natural surface waters.
The boundary of a maintenance way easement adjacent to a
portion of a drainage system within which no building or structure
shall be erected and within which no trees, bushes or other vegetation
shall be planted or allowed to grow which will interfere with the
maintenance of the drainage channel, unless otherwise allowed, as
in an agricultural exclusion.
The agent designated by the Town Board to monitor and enforce
the encroachment limits as defined above.
The removal of sand, gravel, soil, including topsoil or other
natural deposits, by stripping, digging or any other means.
The depositing of natural or artificial material that raises
the existing grade of land or modifies the surfaces of water bodies.
The area of normally dry terrain that becomes covered with
water during and after local or upstream rainstorms and/or ice melt
conditions. The floodplain for a specific watercourse may be defined
in terms of the severity of the precipitation event, which causes
the flooding. Floodplains may be determined from maps prepared by
the U.S. Army Corps of Engineers, by the Federal Flood Insurance Administration
(FIA) or as a result of special engineering studies. Changes in the
natural drainage system may change the locations of the floodplain
limits.
In general, the area through which, or over which, floodwaters
flow at specific levels of runoff severity. The FIA has a special
definition for insurance purposes.
The quantity of water that moves past a given point in a
specified increment of time, usually measured in cubic feet per second
(cfs).
The alteration of the existing grade of land through excavation
or filling.
A network of natural streams, creeks, constructed channels
and ditches or swales employed to convey the flows of natural surface
waters.
An area or structure without an outlet or with a controllable
outlet, intended to collect and store surface water during and after
precipitation to prevent excessive downstream flows. A retention facility
has a normal low water pool above, which is designed freeboard to
contain storm flows.
Rocks or stones placed on soil to prevent erosion from precipitation
or moving water.
The deposition of soil carried by floodwaters.
The removal of overburden, topsoil, soil, vegetation or other
natural material from land.
That portion of natural precipitation which moves across
the land surface, as sheet flow or as channelized flow to permanent
watercourses.
A shallow, relatively wide drainage channel of area, with
flatter side slopes than a ditch, usually covered with grass or other
natural vegetation.
Vegetative material or stable mulch.
The natural surface layer of an undisturbed area of terrain,
usually darker than the underlying layer, ranging in organic matter
content from 2% to 50% and which ranges in texture from loamy fine
sand to clay.
The Town of Williamson.
A stream channel, swale, ditch, etc., contributing flow to
a larger stream or body of water.
The speed of water, usually related in feet per second (fps).
A quantity of water, usually related in cubic feet (cf).
The level below which the soil is saturated with water.
A stream of water. It may be natural or man-made and may
flow seasonally or year round.
The area drainaged by a watercourse, usually divided by a
ridge or crest line of natural topography but sometimes by man-made
constructions. Same as "drainage basin."
Land and submerged lands commonly called "swamps" or "marshes"
which support aquatic or semi-aquatic vegetation, plants or brush.
A.
The design and construction of drainage systems shall be such that
watercourses traversing the development and natural water emanating
from within the development will be carried through and off the development
without injury to improvements, building sites or buildings existing
or to be installed downstream within or adjacent to the development.
Drainage water entering the development shall be received and discharged
at locations and in the manner that existed prior to construction
of the drainage facilities within the development unless special provisions
are made to handle it otherwise. The design of drainage facilities
within the development shall be such that they will conform to the
ultimate drainage requirements of the land within the development
watershed. The discharged flow at the downstream area of the development
shall be conducted in drainage facilities so that the flow effects
shall be restored to pre-development conditions prior to leaving the
development area or reasonably distant therefrom unless approval is
given by the designated Engineer to do otherwise.
B.
Natural drainage patterns shall be employed in preference to rechanneling
streams or watercourses. In no case shall work be performed which
directly or indirectly affects natural drainage patterns without the
granting of approval by the designated Engineer, county and state
agencies having jurisdiction.
D.
No chemicals, fuels, lubricants, or other pollutants shall be disposed
of or deposited into any streams, drainage or water supply systems.
E.
Fill and refuse shall not be disposed of or deposited upon or immediately
adjacent to any wetland, floodplain or drainageway, except where otherwise
permitted.
F.
Man-made structures shall be placed so as not to block or restrict,
in any manner, natural drainage patterns, except where otherwise permitted.
G.
Where land excavations or filling has been permitted, provision shall
be made for the safe conduct of surface water across the face of the
slope, for subsurface drainage as necessary and to prevent materials
from washing across or upon the property of another.
H.
Ponds and retention or detention facilities shall be employed as
required by the designated Engineer.
I.
All drainage systems and stormwater sewer capacity shall be designed
to handle the anticipated flows from the entire upstream drainage
basin when fully developed according to existing zoning, and these
anticipated flows shall be determined by the designated Engineer unless
approval is given by the designated Engineer to size otherwise.
J.
In order to expedite surface drainage, a minimum grade of 0.5% shall
be employed on all newly finished swales, unless otherwise required.
K.
Sedimentation basins shall be employed during or after construction
as required by the designated Engineer to prevent siltation or turbidity
in watercourses or drainage systems.
L.
Surface waters and drainage, where identified as being significant
sources of groundwater replenishment and where such resources are
being utilized as a potable water supply, shall not be revised or
altered except by approval of the designated Engineer.
M.
Any of the above requirements may be waived by presentation of sufficient
evidence as determined by the Town Board.
Except as hereinafter provided, it shall be unlawful for any
person, firm, entity or corporation to:
A.
Modify the topography or surface qualities of any area greater than
20,000 square feet so that the water retention or discharge characteristics
of the area are modified, unless the action has been approved by the
Town Board through its designated Engineer. Recognized agricultural
procedures in active agriculture areas as defined by New York State
Division of Agriculture and Markets are exempted from the regulations
herein defined.
B.
Place, deposit or permit to be placed or deposited any debris, fill,
sand, stone or other solid materials of any kind or nature or construction
of any kind into or across any watercourse, including culverts, pipes,
or other drainage systems that may cause the obstruction or alteration
of flow through the area.
C.
Fill, obstruct, dam, divert or otherwise change or alter the natural
or artificial flow of waters or drainage or the intensity or quantity
of flow through any stream, ditch, pipe, culvert, watercourse or other
improvement or drainage system.
A.
Hydrologic.
(1)
The drainage channels for watercourses numerically identified in the Town of Williamson Storm Drainage Study of 2002 (or any updates) shall be provided to accommodate not less than the minimum flows indicated in that drainage study or the latest similar study accepted by the Town. These values shall be independently verified by the developer or landowner using hydrologic technology described in § 81-5B, and the hydrologic analysis thereof shall become a part of the supporting data of the proposed drainage plans.
(2)
The capacity of the channel that will occupy the ultimate drainage
easement within the development shall be based upon both the existing
degree and anticipated rate of urbanization within the development
watershed and the type of development possible under the Zoning Ordinance
of the Town, as the same may be modified from time to time.[1] Whenever a development may be located within a watershed
undergoing initial stages of urban development, the proposed drainage
system shall adequately pass the flows that would develop from continued
urbanization within the useful life of the proposed channel improvement
or system. Proposed drainage systems within developments located in
watersheds that may be in the advanced stages of urbanization shall
be designed and constructed to pass the project designs flow determined
for the ultimate urbanization of the tributary watershed. Where this
is not practical, storage basins may be provided to increase the capacity
of the drainage systems and control flows to downstream drainage systems
and/or structures such that the capacity of the latter will not be
exceeded.
(a)
These storage basins may be two types, as follows:
[1]
A detention basin, drained by gravity through a control-sized
pipe located at the downstream end of the basin.
[2]
A retention basin utilizing a normal water level, completely
drained usually by pumping. Usually a low water level will remain
in the basin with freeboard designed to accommodate storm flows.
(c)
Storage basins are sized to accept excessive flow over and above
the capacity of downstream drainage facilities. They may be used to
change, in a beneficial way, flows through a proposed development
or from a proposed development.
(3)
For undeveloped areas of the tributary watershed, the surface permeability
classification shall be based upon the Town of Williamson Zoning Maps
and correlated with projected land uses developed by the Town Master
Plan. Wherever a development watershed contains excessive permanent
land uses, such as railroads, public parks, cemeteries and parkways,
such factors may additionally be considered in determining an appropriate
coefficient of runoff.
(4)
Drainage systems classed as "minor" shall be checked by engineering
computations to pass the flow requirements of the next higher design
level.
(5)
Prospective developers and their engineers should consult the "Guidelines
for Erosion and Sediment Control in Urban Areas of New York State"
by the United States Department of Agriculture, Soil Conservation
Service as a publication that contains many resources for handling
and controlling stormwater.
B.
Hydraulic.
(1)
The hydraulic design of development drainage systems shall be in
accordance with modern standard procedures and shall conform to the
latest professional manuals dealing with the many considerations required
for a comprehensive drainage system. The hydraulic design of all drainage
systems shall conform in basic details to the American Society of
Civil Engineers Manual of Engineering Practice No. 37 and such other
applicable manuals as would supplement the ASCE Manual or integrate
advanced and proven hydraulic principles and basic assumptions. Open
and closed drainage systems shall be designed to provide complete
drainage for all elements within the development and shall include
all appurtenances essential for the adequate performance thereof.
The size of conduits shall be selected at grades which produce a minimum
velocity of three feet per second when flowing full.
(2)
A development-grading plan indicating a contour interval suitable
for the map scale shall be provided to show detailed comprehensive
and efficient surface drainage for all lots within and immediately
adjacent to the development.
C.
Structural. Catch basins, manholes, inlet structures and other appurtenances
placed within the development shall be designed to conform to standard
specifications approved by the designated Engineer.
(1)
Channels. The minimum center-line radius of constructed curved channels
shall be at least three times the bottom width of the channel for
subcritical flow. The minimum bottom width of constructed channels
shall be four feet. The creation of excessive numbers of curves in
open channels shall be avoided by reason of the increase in friction
loss and the potential erosion due to spiral flow. Outer bank protection,
especially at the downstream end of the curve and, to a lesser degree,
on the inner bank at the beginning of the curve, may be required by
the Town. Earth channels constructed within the development shall
have side slopes of one on four or flatter, unless otherwise approved
by the Town.
(2)
Enclosed conduits. Except for adequate natural watercourses, all
storm drainage within the development which is capable of being transmitted
in a forty-eight-inch diameter pipe shall be carried in an enclosed
conduit. If it is deemed in the public interest by the Town, this
size may be varied, either increased or decreased, according to topographic
conditions or an economic analysis of the cost of the conduit against
an equivalent open channel, including the occupied land value. The
minimum conduit size shall be 12 inches in diameter. Manholes shall
be provided at all changes in grade and direction. Spacing of manholes
and minimum cover of conduits shall conform to the standard practice
endorsed by the American Society of Civil Engineers. Inverted siphons
shall not be permitted.
All preexisting obstructions or deposits or alterations or diversions
of the natural flow of water or the intensity or quality of flow through
any watercourse or drainage system which cause the inundation of real
property, buildings or other premises or, in the opinion of the Town
Board through its designated Engineer, constitute an undue burden
upon the drainage system or hamper the proper present or future course
of development of the drainage system, or, in the opinion of the Town
Board through its designated Engineer, presently constitute or in
the reasonably foreseeable future will constitute a danger or hazard
to the well-being, safety or general welfare of the residents of the
Town or any property located therein, may be removed or corrected
by the Town upon 10 days' notice by the Town. The Town will endeavor
to replace improvements necessary for essential use of the property,
such as driveway culverts.
A.
Easements for enclosed conduits and appurtenances. An easement not
less than 20 feet in width, sufficient to contain the enclosed conduit
and appurtenances thereof and to provide working space for personnel
and equipment for the servicing thereof, shall be indicated on the
map of the development and designated as follows: "Drainage Easement
to the Town of Williamson." Drainage easements for enclosed conduits
shall, insofar as possible, be placed along or adjacent to lot boundary
lines in a parallel and straight alignment.
B.
Natural and/or man-made watercourses which traverse a development
shall be preserved by an easement of sufficient width, including overbanks,
which will adequately pass the project design flow. The gross allowable
depth of flow shall not create a flood hazard to existing or proposed
development and improvements. The channel and overbank widths, together
with a continuous maintenance way as specified by the Town, shall
constitute the floodway encroachment limits. Wherever such natural
watercourses are endowed with significant natural beauty and have
adequate capacity or have been determined to have value for fish and
wildlife, the developer may dedicate widths in addition to those required
above on the map of the development with the following designation:
"Drainage Easement to the Town of Williamson."
The developer shall submit detailed drainage plans with a report
containing sufficient data for the Town to check the feasibility of
the drainage system as proposed by the developer. The following data
shall be included:
B.
Hydraulic:
(1)
The plan and profile of all drainage systems shall be provided.
(2)
Sizes and types of drainage improvements, including special structures,
typical sections, easement, etc.
(3)
When required, supporting calculations for upstream and downstream
channel capacities as they affect water surface levels and backwaters
within or adjacent to the development. Such calculations shall be
supported by such additional survey information as may be required
to determine a profile and cross section of the upstream and downstream
channel reaches of the development under construction.
(4)
A detailed development-grading plan prepared to suitable contour
intervals with grading details to indicate proposed street grades
and elevations, watercourse grades and elevations, building site elevations
and surface elevations at critical points throughout the development.
(5)
In certain cases, the Town may waive the requirement for detailed
drainage plans of one- or two-lot parcels when the work proposed involves
only minor modifications or alterations to the drainage system. In
the event that detailed plans are waived, the developer shall be required
to submit a drainage plan containing sufficient data for the designated
Engineer to check the feasibility of the drainage system as proposed
by the developer.
A.
The final construction plans for drainage within the development
shall conform to the provisions of the Town of Williamson Planning,
Zoning Board or Master Plan regulations, subsequent amendments thereto
and any particular conditions as required by the designated Engineer
in approving the proposed plans and supporting data thereof. The construction
plans for the drainage requirements shall be approved by the designated
Engineer prior to the construction of any drainage facilities within
the development.
B.
The plans shall bear the certification of a licensed professional
engineer as evidence of the professional responsibility for the drainage
planning within the development and shall contain the following information:
(1)
A vicinity sketch and boundary line survey of the site on which the
work is to be performed.
(2)
Location of any existing buildings, structures, utilities, sewers,
water storm drains and natural features on the site where the work
is to be performed.
(3)
Location of any building or structure on land of adjacent property
owners within a minimum of 50 feet of the site and further as necessary
to show directly affected parcels.
(4)
Spot elevations and existing and proposed contours, dimensioned extent
of all work proposed to be done and existing shrub masses and trees
to be accurately located and labeled.
(5)
A computation of the volume of excavation and fill involved and the
quality of fill.
(6)
Detailed plans of all drainage provisions, retaining walls, cribbing,
vegetative practices, erosion and sediment control measures; excavations
or ponding areas, outfall control devices, outlet weirs, etc., and
other protective devices to be constructed in connection with or as
a part of the proposed work; together with a map showing the drainage
area of land tributary to the site and estimated cubic-foot-per-second
runoff of the area served by any drain, computed in accordance with
current Town development criteria.
(7)
A timing schedule and sequence indicating the anticipated starting
and completion dates of the development sequence, stripping and/or
clearing, rough grading and construction, final grading and vegetative
establishment and maintenance and the time of exposure of each area
prior to the completion of effective erosion and sediment control
measures and any traffic or noise problems.
(8)
The depth to bedrock as determined during site evaluation.
(9)
The depth to water table as determined during site evaluation.
(10)
The types of soils encountered as determined during the site evaluation.
C.
All drainage construction shall be subject to inspection by the designated
Engineer. Any field changes which affect the intent of these provisions
shall have the prior approval of the designated Engineer.
D.
In certain cases the Town may waive the requirement for detailed
construction plans and certification of plans by a licensed professional
engineer on parcels when the work proposed involves only minor modifications
or alterations to the drainage system. In the event that detailed
plans are waived, the developer shall be required to submit construction
plans containing sufficient data for the Town to check the feasibility
and adequacy of the drainage system as proposed by the developer.
A.
Any person, firm, corporation or entity found to be violating any
of the provisions of this chapter shall be served with a written notice
by the Town stating the nature of the violation and providing a thirty-day
time limit for the satisfactory correction thereof, subject to appeal
to the Town Board within 10 days.
B.
Any person, firm, corporation or entity who shall continue any violation beyond the time limit provided for in Subsection A shall be guilty as follows:
(1)
For a first offense or violation, punishable by a fine of not more
than $250 or by imprisonment not to exceed 15 days, or by both fine
and imprisonment; and
(2)
For a second offense occurring within one year after the conviction
of a first offense of a Class A misdemeanor, punishable by a fine
of not more than $1,000 or by imprisonment not to exceed one year,
or both fine and imprisonment; and
(3)
In addition to the foregoing, by a penalty of $500 to be recovered
by the Town of Williamson in civil action.
(4)
Each and every day that a violation of any of the provisions of this
chapter exists shall constitute a separate violation.
C.
Any person, firm, corporation or entity violating any of the provisions
of this chapter shall become liable to the Town for any expense or
loss or damage occasioned by the Town by reason of such violation.
The Town shall have the right to assess all such expenses against
the land on which the violation occurred and to bring legal action
to recover such expenses.
The approval of plans for proposed drainage systems and flood
hazard prevention requirements shall not constitute a representation,
guaranty or warranty of any kind or nature by the Town of Williamson
or by an officer or employee thereof of the safety, operation, adequacy
or intent of the proposed facilities and shall create no liability
upon or cause for action against such public body, officer or employee
for any damage that may result from construction pursuant thereto.
A.
Drainage District Fund Matrix.
|
Unit Category
|
First Acre
(or portion thereof)
|
Excess Acreage
(rounded to the nearest acre)*
|
|---|---|---|
|
Vacant/farm land (no structure)
|
25 units
|
1 unit per acre
|
|
Vacant/farm land (structure)
|
50 units
|
1 unit per acre
|
|
Residential land with single-family dwelling
|
50 units
|
1 unit per acre
|
|
Residential land with multiple-family dwelling, up to 4 living
units
|
2 units: 60 units
3 units: 70 units
4 units: 80 units
|
1 unit per acre
|
|
Manufactured house park
|
100 units
|
100 units per developed acre; 1 unit per undeveloped acre
|
|
Commercial or industrial developed
|
125 units
|
125 units per developed acre; 1 unit per undeveloped acre
|
|
High-density development exceeding 1 acre
|
125 units
|
125 units per developed acre; 1 unit per undeveloped acre
|
|
*
|
NOTE: Rounding of excess acreage is based on the notion that
0 to 0.5 is not an additional acre.
|
B.
Determination of exemptions.
(1)
Property owners apply to the Town Board to determine the allowable
amount that would be permitted for the project.
(3)
The Town Board has the authority to grant exemption for fees or partial
fees.
(4)
Fee exemptions may extend up to five years of fee relief but may
not exceed the overall project cost, or, in cases of joint projects,
the relief may not exceed the expenditure by the participating property
owner.
A.
Two or more property owners will be directly impacted by the project.
B.
There shall be evidence that the Town of Williamson had not properly
provided for easements, maintenance or repair of drainage systems
critical to providing the health, safety or welfare of persons or
property.
C.
Flooding of property has been documented to occur on an annual basis
or more frequently.
D.
Floodwaters have been documented to back up into basements, garages,
homes, or other buildings on the property, or across public roadways
adjoining the property, or otherwise have threatened the structural
integrity of such structures or facilities.
E.
The property owners shall provide plans to correct the problem which
have been properly designed as determined by the Williamson Watershed
Management Advisory Council.
F.
Reimburse costs at 50% of project cost, not to exceed $10,000.
