The definitive plan consists of a top sheet, as described in §
365-34, which meets the design standards of §
365-36, which may contain more than one sheet and which is designed to be recorded at the Registry of Deeds and whose prime purpose is to be used for the conveyance of lots and as a permanent record of the final engineering design of the subdivision, and the following attachments, as described in §
365-39, which, unless otherwise specified, shall be in the same scale as the definitive plan but which need not be on linen. One sheet or plan may meet more than one requirement but it shall be labeled to show its purpose, such as "Site Survey Map."
By the time of the public hearing, the following,
which shall be paid for by the developer, shall be shown on the top
sheet of the plan:
A. The location, grade and size of water mains and tie-in
to town system as determined by the Board of Water Commissioners;
or if town water is not to be used, the proposed water supply system.
The minimum diameter of the water mains shall be eight inches.
B. The location of hydrants as determined by the Superintendent
of the Water Department. The center of the front of each lot shall
be no more than 500 feet from a hydrant.
C. The exact location of streetlights as determined by the manager of the Municipal Light Department. Streetlights shall be paid for by the developer. Underground distribution systems shall be provided for any and all utility services, including electrical and telephone services. Poles and any associated overhead structures of a design approved by the Planning Board after consultation with the Electric Light Manager shall be provided for police and fire alarm boxes (as provided in Subsection
E) and any similar municipal equipment and for use for streetlighting.
[Amended 12-3-1986 (Amdt. E); 4-9-1990 (Amdt. I)]
D. The location of a bench mark with its height above mean sea level given, related to USCGS data. See §
365-39H.
E. The location of fire alarm boxes and tie-in to existing
system, as determined by the Fire Chief.
F. The location of underground lines as described in Subsection
G.
[Added 8-19-1987 (Amdt. G)]
G. Show the location of underground lines, including
proposed present or future water, electric, telephone, fire alarm,
drainage, gas and cable television, on the plan and on cross section
of the street (Sketch B revised February 1996) using these guidelines:
Water mains shall have a minimum of five feet of cover and shall be
placed in the grass strip between the sidewalk and the road. All other
aspects and plans for the water services shall conform to the specifications
of the Georgetown Water Department and shall be approved by the Water
Superintendent prior to installation. All other utility services shall
conform with and receive approval of the respective utility prior
to installation. All appropriate safety standards and procedures shall
be incorporated into the plans.
[Added 8-19-1987 (Amdt. G); amended 4-3-1996]
H. Individual lot and road closure calculations shall
be submitted the Board of Review.
[Added 4-3-1996]
[Added 10-25-2000; amended 2-26-2020]
For preliminary and definitive plans creating
no more than two residential lots, the following regulations shall
apply:
A. Preliminary plans. The plan shall comply with Article
III, Preliminary Plan, of these regulations.
B. Definitive plans. The plan shall comply with Article
IV, Definitive Plan Procedure, of these regulations.
C. Contents of definitive plan. The plan shall comply with Article
V, Contents of Definitive Plan, of these regulations.
D. Subdivisions shall be designed in conformance with §
365-36, Design standards.
E. Stormwater calculations required under these regulations shall be calculated utilizing the regulations promulgated under Chapter
57, Erosion and Stormwater Control, with respect to the latest rainfall data available.
[Added 10-25-2000; amended 2-26-2020]
For preliminary and definitive plans creating
no more than five residential lots, the following regulations shall
apply:
A. Preliminary plans. The plan shall comply with Article
III, Preliminary Plan, of these regulations.
B. Definitive plans. The plan shall comply with Article
IV, Definitive Plan Procedure, of these regulations.
C. Contents of definitive plan. The plan shall comply with Article
V, Contents of Definitive Plan, of these regulations.
D. Subdivisions shall be designed in conformance with §
365-36, Design standards.
E. Stormwater calculations required under these regulations shall be calculated utilizing the regulations promulgated under Chapter
57, Erosion and Stormwater Control, with respect to the latest rainfall data available.
There shall be attached the following:
A. Cover page. A cover page shall contain the name of
the subdivision, owner, developer, location map, number of total acres,
number of lots planned, number of dwelling units planned, type of
sewage disposal planned, type of water supply, name of designer, engineer,
land surveyor, zoning district.
B. Site survey map. A site survey map shall contain a
title block, bar scale, north point, permanent monument with its height
above mean sea level related to USCGS data, existing topography based
on a current survey showing date of survey, contours at two-foot intervals,
existing watercourses and drainage ditches, including direction of
flow, with existing spot elevations from their respective source of
entrance into the subdivision to their respective termination or exit
therefrom, swamps, other bodies of water and low areas subject to
flooding, all existing drainage structures with elevations, natural
and historic features, major site features such as rock ridges and
ledge outcroppings, outline of existing buildings, streets, trails,
etc., exact location of percolation tests and of test pits, if any
have been taken, with attached table showing date of test, reading
of maximum groundwater table elevation and core samples, all related
to USCGS data, floodplain zoning limits, adjacent developments. Proposed
streets and lot lines shall be shown in a general manner. Scale shall
be one inch equals 40 feet unless the Board previously authorizes
a different scale. It shall show existing streets in or within 100
feet of the subdivision, indicating location and name, type surface
and width of pavement and right-of-way, profiles within subdivision,
spot elevations outside to define grades. It shall show existing utilities,
size, type and location as to water mains, drains and culverts, wells,
septic tanks (fields), gas, electric, telephone, cable television
and other overhead or underground utilities.
[Amended 7-18-1973 (Amdt. B)]
C. Watershed outline and drainage plan.
(1) A plan shall show the outline of watershed and subwatershed
areas carried out to an existing stream or drainage system even though
beyond the limits of the subdivision. An insert may be necessary to
show this clearly. Existing drains and culverts and proposed culverts
and drainage system, including direction of flow, shall be shown.
Existing stream courses and proposed changes shall be shown. Streams
within 200 feet of the limits of the subdivision shall be shown. It
shall show subsurface drainage, downstream restrictions that could
cause backup of water or could impede drainage. Proper connections
shall be shown with any existing drains in adjacent streets or easements
where they may exist and prove adequate to accommodate the drainage
flow from the subdivision, and in the absence of such facilities or
the adequacy of the same, it shall be the responsibility of the developer
to extend drains from the subdivision as required to properly dispose
of all drainage from said subdivision in a manner determined by the
Board.
(2) An applicant shall, before final approval of a subdivision,
submit runoff calculations computed by a qualified registered engineer
of the maximum surface drainage which will be shed by the road systems
and area within the subdivision and demonstrate to the reasonable
satisfaction of the Planning Board that:
(a)
The drainage system within the subdivision is
adequate to carry off surface drainage caused by rain, snow and ice
without flooding of roads, sidewalks or adjacent property within the
subdivision. Consideration should be given to the requirements of
drainage from individual lots into the system, where needed. However,
such use by private parties must receive prior approval from the Board
of Health.
(b)
The drainage system, although adequate for the
purposes described in this section above, will not wrongfully discharge
such surface water upon or flood the property of others which is located
outside of the subject subdivision.
(c)
The drainage system, although adequate to satisfy
the provisions above, will not wrongfully overburden continuous existing
drainage systems, either natural or artificial, located outside the
subject development, with the result that such off-site drainage systems
wrongfully flood or overflow the property of others located either
outside or within the subject development.
(3) Stormwater planning and design standards.
[Added 4-26-1995]
(a)
Water quantity and water quality control are
important components in stormwater management planning and implementation.
Equally important are the overall plans for capture and disposal of
drainage water. The Planning Board shall participate with other boards
and the Highway Surveyor to ensure that systems approved for installation
are consistent with health, safety and environmental concerns of the
community. The approach to controlling and treating stormwater runoff
and the kind, number and locations of facilities will be evaluated.
Facilities which have short life expectancies, low effectiveness and
high operation and maintenance costs will generally not be acceptable
to the Planning Board.
(b)
The following shall constitute the Planning
Board's basis for the planning and preparation of stormwater control
plans.
[1]
Maintenance of existing drainage patterns. Drainage
easements, acceptable to the Planning Board, will be required where
changes in watershed drainage patterns result in new discharges of
stormwater onto downstream owners or where flows are changed from
overland sheet flow to concentrated flow, unless the applicant can
demonstrate to the satisfaction of the Planning Board that there will
be no significant impact from discharges for the two-year, ten-year,
fifty-year and one-hundred-year, twenty-four-hour storms.
[2]
Hydrologic and hydraulic analysis of proposed
drainage systems. The applicant will identify the upstream and on-site
drainage areas and perform a downstream analysis to determine where
conditions such as lack of channel capacity or constrictions in the
system exist, and which could result in problems such as but not limited
to increasing water levels on adjacent properties, flooding of roads
or septic systems, channel scouring or destruction of aquatic habitat.
[3]
Sediment and erosion control plan. An engineering
plan, stamped by a Massachusetts registered professional engineer,
must be prepared for sediment and erosion control, including measures
to control sediment and dust at all access points, stabilization practices
which will be implemented to reduce erosion of soil from disturbed
areas and to collect sediment-laden runoff water during construction
and a plan showing final stabilization practices after construction
is complete. Accompanying the submission shall be a schedule showing
anticipated construction dates and the timing sequence of implementation
of the proposed sediment and erosion control practices.
[4]
Operation and maintenance plans. A plan which
outlines how stormwater, sedimentation and erosion control facilities
are to be maintained must be submitted with the final definitive subdivision
plans. The plans must include operation and maintenance of both temporary
and permanent practices and facilities implemented for the periods
during construction and after project completion when accepted by
the town. Unless otherwise waived, the following requirements apply
to all projects under the jurisdiction of the Georgetown Planning
Board, MGL c. 41. These requirements are based upon the minimum level
of stormwater management needed to meet criteria established by Section
6217 of the Coastal Zone Management Act (1990).
[a] Water quantity.
[i] Proposed projects must control
postdevelopment peak discharge rates from the two-year and fifty-year
storm events at predevelopment levels.
[ii] Where downstream analysis of the
one-hundred-year storm event indicate existing or potential future
problems from excess runoff generated by development of the watershed,
the control of peak discharges for the one-hundred-year storm shall
be required to mitigate the downstream impacts.
[iii] The discharge from any stormwater
facility must be conveyed through properly constructed water-control
facilities which provide for nonerosive flows during storm events.
Street drains (storm drains, catch basins, etc.) shall be designed
using the ten-year storm as a minimum level of protection. Other stormwater
conveyance systems such as but not limited to road culverts, detention
ponds and channels shall, as a minimum, accommodate the runoff from
a fifty-year storm event. If important or high-risk facilities such
as roadways, dwellings, commercial and industrial buildings or sanitary
facilities might be threatened by uncontained flows or flooding from
higher frequency storms, a one-hundred-year storm frequency design
standard shall be applied.
[iv] All stormwater detention basins
and similar structural facilities which store water, and/or where
failure could result in damage to the facility or to downstream areas,
must be constructed to safely accommodate discharges from the one-hundred-year
storm event. A plan or profile of each proposed detention facility
shall show the following:
[Amended 4-3-1996]
[A] {a} Depth to seasonal high groundwater
and date of observation.
[B] {b} A section through the stone
infiltration trench if proposed.
[C] {c} Details of the outlet structure.
[D] {d} Specific dimensions of the
proposed emergency spillway.
[E] {e} Velocity reduction structures
if the scope of the inlet pipe is greater than 2% or if the velocity
of flow in or out of the basin is greater than five feet per second.
[F] {f} Inlet and outlet piping.
[I] {i} Other, such as earth berm details,
anti-seep collar and a headwall plan view should be included on the
detail sheet.
[v] Applicants must demonstrate that
the above requirements are met by submitting pre- and postdevelopment
composite hydrographs. An acceptable methodology for determining runoff
volumes, peak discharge rates and storage requirements are the Soil
Conservation Service's revised Technical Release 55 (TR-55). More
suitable for some analysis is TR-20 where multiple or complex watersheds
occur. The twenty-four-hour, TYPE III distribution storm must be analyzed
when using the SCS method. For pavement drainage calculations needed
to size roadway storm drains and similar components, the Rational
Method is the preferred technique.
[b] Water quality.
[i] Water quality management facilities
shall be designed to treat the volume of runoff calculated by multiplying
one inch by the total impervious area contained within the project
area. An additional volume increase for 10 years of sediment storage
must be added to this volume capacity. This volume calculation is
a design standard which must be applied as specified in the following
practices.
[ii] Wet ponds must have a permanent
pool volume at least equal to the quantity volume described in Subsection
C(3)(b)[4][b][i]. The length to width ratio measured from the stormwater
inlet to the pond outlet shall be at least 3:1 with an average permanent
pool depth of three to six feet.
[iii] Extended detention dry ponds
must detain the water volume for a minimum of 36 hours (full volume
to drawdown time). Two stage basins utilizing the lower stage for
water quality and the upper stage for floodwater detention are acceptable.
Basin bottoms shall not be closer than one foot to the seasonal high
ground water level. The minimum length to width ratio shall be 3:1.
A six-inch layer of loam shall be applied to the basin floor and sides
and seeded to appropriate grass species.
[iv] Infiltration practices must be
designed to exfiltrate the stormwater quantity volume within 72 hours.
Appropriate sediment removal techniques must be applied prior to stormwater
entering the infiltration facility. The minimum distance between the
bottom of the infiltration facility and the seasonal high groundwater
level shall be three feet.
[v] Vegetated swales shall be a minimum
of 100 feet in length and designed to carry the runoff volume at velocities
not greater than 1.5 feet per second and at a depth of not more than
four inches. The maximum design (bank full) velocity for any vegetated
swale shall not exceed five feet per second. High groundwater levels
or bedrock shall occur at least two feet below the bottom of the vegetated
swale.
[vi] Stormwater discharges to certain
critical areas but not limited to swimming beaches or drinking water
supplies may require a higher design level to control the effects
of potential pollutants such as bacteria, nutrients, soluble metals,
organic compounds and toxics. The amount of impervious surface area
and the scope of the proposed project all generally dictate the kind
and magnitude of practices needed to achieve a goal of removing a
high percentage of total suspended solids. Sites having impervious
drainage areas less than 0.25 acres in size may find that vegetated
swales or filter strips are sufficient to treat stormwater discharges.
Larger drainages will usually require more complex systems to treat
the proportionally larger volumes of stormwater.
[vii] Stormwater drainage catch basins
shall be equipped with gasoline traps of a type acceptable to the
Board.
(4) In complying with provisions of this Subsection
C, the applicant for approval must submit with his definitive plan the following detail:
(a)
With respect to the area within the development:
[1]
Runoff data and computations of storm sewers
or open ditch directional requirements, based on a minimum of a ten-year
storm period.
[2]
Design of stormwater storage facilities intended
as a flood-control measure, if any.
[3]
Profiles and cross sections of waterways and
drainage lines off the roadways will be shown as far as necessary
to ensure that flooding will not occur.
(b)
With respect to the area outside the development:
[1]
An estimate based upon engineering studies and
measurements of the additional capacity of all seasons of off-site
drainage facilities, either natural or artificial, to which the drainage
facilities of the subject development will be connected.
[2]
Topography of upstream and downstream drainage
areas adjacent to and affected by the subdivision. Contour interval
to be determined by Planning Board.
(5) If the Planning Board determines that the provisions
in the applicant's definitive plan for disposal of surface drainage
do not satisfy the requirements of this regulation, the Planning Board
may require that the applicant provide suitable off-site drainage
facilities outside the area of the development which is shown on the
applicant's plot plan so that surface drainage may be adequately and
properly accommodated and disposed of to the reasonable satisfaction
of the Planning Board. The applicant must furnish to the Planning
Board a plan showing the design of such off-site drainage facilities
and the certificate of a competent qualified engineer that in his
opinion the design of such off-site drainage facilities is adequate
to accommodate and dispose of the maximum surface drainage which may
be shed by the area shown upon applicant's plot plan.
(6) There shall be shown proposed elevations, slopes and
grades of proposed changes of stream courses. Structural details,
including slopes, grades, sizes, elevations, material, design capacity
and proposed velocity shall be shown. Notes on the plan shall indicate
vegetative or other treatment that will be used to stabilize disturbed
areas and erosion during construction.
D. Wetland Protection Law and Bylaw statement. There shall be attached a statement setting forth whether the plan involves the removal, filling, dredging or altering of any bank, meadow or swamp bordering on any stream or pond or any land subject to flooding, whether within the subdivision or not, and if so shall state whether or not such area is or may be significant to private, public or ground water supply or to flood control or to prevention of pollution and in what manner it may be significant. See MGL c. 131, § 40, and Chapter
161, Wetlands Protection, of the Code of the Town of Georgetown.
[Amended 12-3-1986 (Amdt. E)]
E. Floodplain statement. There shall be attached a statement setting forth whether or not any part of the subdivision area is shown as within the floodplain district on the floodplain zoning map as on file in the office of the Town Clerk, and if so, the relevant floodplain contour shall be shown on the plan. See §
165-28 of Chapter
165, Zoning.
F. Statement of designer. There shall be attached a statement signed by the designer stating "The attached plan complies with Articles
V and
VI of the Georgetown Subdivision Regulations and with the Zoning Bylaw, except as follows:........"
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Signed_________________Sealed______________________19___
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Designer____________________________________
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G. Applicant shall submit the following receipt (Form
R): This will acknowledge receipt of Georgetown Subdivision Regulations
adopted Dec. 20, 1972, and it is agreed that they apply to the preliminary
_____ ; definitive ____ plan entitled "______________________________"
[Added 12-3-1986 (Amdt. E)]
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It is hereby agreed to comply with said regulations
and to comply with the definitive plan as endorsed by the Planning
Board.
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Signed __________________
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________ 19_____
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Applicant
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H. Flood insurance statement. There shall be attached
a statement stating which lots, if any, are shown by the applicable
FIRM map of FEMA (Community Panel 250081, effective date June 4, 1980)
to be in the one-hundred-year-flood level, and such line shall be
shown on the applicable lots.
[Added 12-3-1986 (Amdt. E)]
I. Erosion and sediment control plans.
[Added 4-3-1996]
(1) The definitive plan shall contain provisions for erosion
and sediment control which fully apply the following principals:
(a)
Plan and utilize land and water resources giving
prime consideration to site suitability and soil limitations based
on soil surveys and interpretations.
(b)
Develop an overall plan for land use, erosion
control and water management.
(c)
Protect adjoining property from damage or hazard
from land-disturbing operations.
(d)
Make best use of existing topography and natural
land features to fullest extent possible.
(e)
Limit clearing, grading and slope modifications
to those consistent with good land use.
(f)
Conserve and utilize existing vegetative cover
to fullest extent possible.
(g)
Make permanent vegetative plantings that are
compatible with specific soil and site conditions.
(h)
Control erosion and runoff.
(i)
Protect surface and subsurface waters from pollution.
(j)
Control dust and tracking of mud from property.
(k)
Protect stockpiles from wind and water erosion.
(2) One or more sheets of the definitive plan shall contain
the following information:
(a)
A description of the sequence of construction,
anticipated starting and completion dates, and best management practices
which will be applied to control erosion and sedimentation, including
but not limited to:
[1]
Site mobilization and access.
[2]
Installation of temporary erosion and sediment
control measures.
[3]
Tree cutting, clearing and grubbing.
[4]
Sediment basin installation.
[5]
Roadway rough construction.
[6]
Drainage system construction.
[8]
Roadway base and bender construction.
[9]
Curb and sidewalk construction.
[10]
Site cleanup, including removal of stones, stumps
and other temporarily stored materials.
[11]
Finish slope grading, stabilization, topsoiling,
liming, fertilizing and seeding.
[12]
Final completion of drainage system and sediment
control practices.
[13]
Removal of temporary erosion control structures
and facilities.
(b)
A plan or plans showing:
[1]
The area to be disturbed during construction
(limits of work).
[2]
Areas where earth or other site materials will
be temporarily stockpiled.
[3]
Areas to be used for disposal of stone if on
site.
[4]
Location of temporary and permanent erosion
and sediment control measures, including sediment basins, stormwater
control basins, diversions, rip-rap and waterways.
[5]
Location of temporary access and work roads.
J. GIS mapping.
[Added 10-25-2000]
(1) Prior to final approval and endorsement of the subdivision
plan by the Planning Board, the applicant shall submit two copies
of the approved version of the definitive plan on two 31/2 inch diskettes
in AutoCAD Version 13 (or any subsequent release that the Town of
Georgetown adopts) to the Planning Board for review and approval.
The computer version of the plan shall be identical, full size, and
shall contain all information included on the printed plan. Each feature
depicted in the subdivision plan shall have its own distinct data
layer within the CAD system (i.e., lines representing each side of
a property parcel). Where property parcels are depicted, the property
parcel data layer shall be a distinct layer within the system. Polygons
representing property parcels must be closed and no other data layer
shall be used to close the polygon. Data shall be produced and depicted
using either the Massachusetts State Plan Coordinate System (1927
Datum in feet) or the Massachusetts State Plan Coordinate System (1983
Datum in meters). Each CAD sheet shall have a minimum of four survey
quality control points depicted on both the hardcopy maps and the
digital CAD file. These control points shall be survey quality and
accurate to plus or minus one centimeter. Layer names shall conform
to Planning Board standards. Digital files shall be accompanied by
information (or a text field) that defines and describes each layer
contained within the submittal files(s). Data files shall be provided
in an IBM-PC (or compatible) format file system.
(2) Failure to submit such diskettes to the Planning Board
shall be cause for the Planning Board to rescind approval or not to
endorse said plan.
(3) All diskettes shall be of high quality, free from
any and all defects and viruses, and labeled as to their contents.
Diskettes shall be prepared with a back up and be sequentially numbered.
The applicant shall provide to the Planning Board a descriptive list
of all files submitted, which documents file contents and intended
use.