The purpose of good subdivision and site design is to create
a functional and attractive development, to minimize adverse impacts,
and to ensure that a project will be an asset to the community. To
promote this purpose, land development projects and subdivisions shall
conform to the following standards which are designed to result in
a well-planned community without adding unnecessarily to development
costs. These design and improvement standards are to promote high
quality development in character with the rural nature of the Town
of Portsmouth, help create neighborhoods and non-residential areas
that are pleasant and functional, help create roads and other public
improvements that serve their intended purposes for generations to
come at minimal added cost to the taxpayer, and to minimize adverse
environmental impacts of development.
The applicant, at his own expense, shall construct all improvements
required by the Planning Board as part of its approval of any subdivision,
in accordance with the specifications of these Rules and Regulations.
1.
Paper streets. Where access to property being subdivided
is proposed to be from streets which are platted but either not constructed
or inadequate as to width or condition, the applicant shall be required
to construct said access street, in full accordance with this Article,
from the public street(s) to one (1) or more of the roads to be constructed,
as determined by the Planning Board.
2.
Professional standards. Wherever it is mandated by these
Regulations that certain tasks associated with subdivision plans and
improvements be performed by registered professional civil engineers,
registered land surveyors, and/or landscape architects, as appropriate
and required. All such tasks shall be performed according to existing
and amended standards of the State of Rhode Island and Providence
Plantations Board of Registration for Professional Civil Engineers
and Board of Registration for Land Surveyors.
3.
Generally accepted engineering principles. Any situation,
definition, or practice not fully covered by these Regulations shall
be done according to generally accepted engineering principles.
4.
Construction sequence. The applicant shall provide and
be bound by a sequence of development and construction activities.
As part of the final plan approval, the applicant shall submit for
approval a sequence of major activities including installation of
drainage facilities, construction of streets or street segments, landscaping,
erosion controls, and utilities. This approved sequence may be amended
from time to time. Minor changes may be approved by the Public Works
Director in consultation with the Administrative Officer. Major changes
such as the sequence of construction of streets, must be approved
by the Planning Board.
[Added 4-29-1998]
1.
Design
of the development shall take into consideration all existing Town
and regional plans for the surrounding community. In designing a subdivision,
the Board shall require the applicant to incorporate the standards
herein.
2.
Preservation of unique and natural features. Development
of the site shall be based on the characteristics of the site and
upon the site analysis. To the maximum extent practicable, development
shall be located to preserve the natural features of the site, to
avoid areas of environmental sensitivity, and to minimize negative
impacts and alteration of natural features, historic and cultural
resources, and areas of scenic value which contribute to the character
of the Town.
a)
Among other considerations the Planning Board shall consider are
the prevailing winds, flooding, hurricane damage, adjoining land uses,
topography, swampy areas, health, welfare and safety. Existing stream
channels should be preserved.
b)
Environmental features such as stone walls, specimen trees, water
bodies or other outstanding natural or man-made features shall be
retained insofar as possible, and incorporated into the design of
the subdivision so as to preserve the character of the land.
c)
Where possible, extensive heavy grading or filling should be avoided.
Development and disturbance of natural features shall be avoided in
areas having a slope of greater than twenty percent (20%).
d)
The development shall be laid out to avoid adversely affecting ground
water and aquifer recharge; to take full advantage of the terrain
characteristics and contours to reduce the cuts and fills; to avoid
unnecessary impervious cover; to prevent flooding; to provide adequate
access to lots and sites; and to mitigate adverse effects of shadow,
traffic, drainage, and utilities on neighboring properties.
e)
The following specific areas shall be preserved as undeveloped open
space or lot area, to the extent consistent with the reasonable utilization
of land, and in accordance with applicable state or Town regulations:
(1)
Unique and/or fragile areas, including freshwater wetlands and coastal
features;
(2)
Significant trees or stands of trees, or other vegetative species
that are rare to the area or are of particular horticultural or landscape
value;
(4)
Steep slopes in excess of twenty percent (20%) as measured over a
ten (10)-foot interval unless appropriate engineering measures concerning
slope stability, erosion, and resident safety are taken;
(5)
Habitats of endangered wildlife, as identified on applicable federal
or state lists; and
(6)
Historically significant structures and sites, as listed on federal
or state lists of historic places.
3.
Site analysis. An analysis of the subdivision site and
nearby areas shall be required by the Planning Board for all major
subdivisions. The scope and content of the site analysis shall be
discussed during the pre-application meeting and shall be presented
by the applicant during the Master Plan stage of review. Such an analysis
may be required by the Planning Board for minor subdivisions if the
Board finds that the proposed development may have a negative impact
on the existing natural and built environment or would be inappropriate
for the character of the surrounding neighborhood.
a)
Such a site analysis shall include written and/or graphic analysis
of the following characteristics of the development site: site context;
geology and soil; agricultural lands; wetlands; coastal features;
topography; ecology; existing vegetation, structures, and road networks;
visual features; and past and present use of the site.
4.
Residential
lot design standards.
a)
Lot dimensions - general. All lots shall be designed so as to contain at least the Minimum Developable Land Area required by Article IV of the Zoning Ordinance, and so that intended structures and improvements may be constructed within the limits of the Land Use Requirements Table therein.[1]
(1)
Lots in a subdivision not served by a public sewer or water district
shall be a minimum of forty thousand (40,000) square feet of developable
land area, or as otherwise designated by the Zoning Ordinance, and
designed to comply with State regulations on the separation of drinking
water wells from ISDS and from the property line, street or other
structures.
(2)
A subdivision of land located in an area served by a public water
district shall be predicated upon said subdivision being serviced
by said public water district. In order to obtain the benefits of
the smaller lot area and other lowered requirements of subdivisions
in a public water district, said owner must utilize public water district.
Intention to do so shall be evidenced by approval of detailed plans
for the installation of public water lines by the appropriate water
district, which shall be required prior to final approval and recording
of the plat.
(3)
In the event any subdivision of whatsoever nature is developed in
a public water district wherein the owner does not utilize said facilities,
all requirements as to said subdivision shall be based upon and shall
be the same as those specified in areas not within a public water
district.
b)
Lot configuration. The Planning Board may
prohibit or require modification to lots shaped or configured so as
to conflict with the use of the land for the intended purpose. Long,
narrow strips of land, unusual shapes, angles, dimensions, and usable
portions separated by easements shall be avoided. The Planning Board
may vary street locations, lot shapes and dimensions, yards, and setbacks
for the purpose of encouraging and promoting flexibility, economy
and environmental soundness in layout and design, provided that the
lots' areas and dimensions, yards, and setbacks within the subdivision
conform to the minimum requirements of the Zoning Ordinance,[2] and provided that such standards shall be appropriate
to the type of development permitted.
(1)
All lots shall have frontage on a public street equal to the minimum
lot width specified in the Town's Zoning Ordinance. For purposes
of these Regulations, streets platted but not improved or accepted
for maintenance by the Town, shall not be considered existing improved public streets. Where these streets are incorporated within
the subdivision, they shall be improved by the developer to meet the
Subdivision Regulation standards.
(a)
With the written approval of the Planning Board, a lot may have
less frontage than that required by the Zoning Ordinance on a cul-de-sac
turnaround provided that the distance between the side lot lines on
opposite sides of the lot as measured at the front yard depth is no
less than the lot width required by the Zoning Ordinance for that
zoning district.
(b)
With Planning Board approval, lots created pursuant to Article VIII of the Zoning Ordinance and consisting entirely of "common lands" as those terms are defined in Article VIII, Section C.7.(a) & (b) of the Zoning Ordinance, and lots set aside for permanent open space or recreation purposes pursuant to Article VI, Section C.4.c) of the Portsmouth Land Development and Subdivision Regulations may be exempted from the requirement of possessing frontage on a public street.
[Added 6-23-1999]
(2)
Irregular shaped lots other than on a cul-de-sac may receive special
consideration by the Board in that lot frontage may be determined
at a depth of thirty feet (30'), radially opposite and concentric
with the front boundary providing that the front boundary line is
not less than seventy-five feet (75') in length. This thirty-foot
(30') strip to be excluded from the overall lot size requirement.
(3)
Side lot lines shall be at right angles to street lines or radial
to curved street lines unless the Planning Board determines that a
variation from this rule will provide a better street or lot plan.
c)
Every lot shall have sufficient access to it for emergency vehicles
as well as for those needing access to the property in its intended
use.
d)
Vegetated buffer areas shall be required where necessary to avoid
adverse impacts from adjacent uses.
5.
Commercial and industrial development design. Commercial
and industrial developments shall be designed according to the same
principles governing the design of residential developments; namely,
buildings shall be located according to topography, with environmentally
sensitive areas avoided to the maximum extent practicable; factors
such as drainage, noise, odor, and surrounding land uses considered
in siting buildings; sufficient access shall be provided; and adverse
impacts buffered.
6.
Traffic sensitive districts.
[Amended 4-29-1998[3]]
a)
Traffic Sensitive Districts are established for the following purposes:
(1)
To facilitate the movement of traffic along major roads in Portsmouth
in a safe and orderly manner;
(2)
To reduce the number of and increase the spacing of driveways which
may disrupt traffic flow;
(3)
To reduce infringement on the rights of the public to travel roadways
in a safe manner, while at the same time providing for adequate access
and egress to properties; and
(4)
To protect the public safety along major thoroughfares in the Town
where accidents have frequently occurred.
b)
All driveway openings onto streets listed in Subparagraph f) of this
Subsection shall have suitable turnaround space so that automobiles
do not back out onto said streets.
c)
On any lot with frontage on the streets listed in Subparagraph f)
of this Section the following shall apply:
(1)
Only one (1) driveway or curb opening onto
streets listed in Subparagraph f) of this Section shall be created
to serve the original lot; or
(2)
Future subdivision or lots created from the original lot shall be
served by a single common driveway or curb opening onto the streets
listed in Subparagraph f) of this Section; or
(3)
A public street or street system approved by the Planning Board under
the provisions of the Rules and Regulations Regarding the Subdivision
of Land shall be created to serve all subsequent lots created from
the original lot.
d)
Common driveways, rights-of-way or other common means of access to
adjacent streets listed in Subparagraph f) of this Section shall be
reviewed and approved by the Planning Board or Zoning Board of Review
before any building permit shall be issued for lots created from the
original lot.
e)
When a tract fronting on a public street designated herein or in
the Town's Zoning Ordinance as in a "Traffic Sensitive District"
is to be subdivided into more than ten (10) lots, the Planning Board
may require that the lots adjoining the existing street be provided
with frontage on a marginal access street, and that access to the
public street be restricted.
f)
This Section shall be applicable only to lots having frontage on
the following streets:
[3]
Note: Changed 4-29-1998 from '6 TRAFFIC SENSITIVE
DISTRICTS - RESTRICTION OF ACCESS. When a tract fronting
on a public street designated herein or in the Town's Zoning
Ordinance as in a" Traffic Sensitive District" is to be subdivided
into more than 10 lots, the Planning Board may require that the lots
adjoining the existing street be provided with frontage on a Marginal
access street, and that access to the public street be required.'
1.
General standards.
a)
Streets in the subdivision shall be coordinated with each other and
with the existing street system in a manner satisfactory to the Planning
Board, with due regard to securing safety, and emphasizing the attractiveness
of the street layout.
b)
The arrangement of streets shall be considered in relation to the
existing street system, and to existing topographic and natural conditions.
The road system shall be designed to permit the safe, efficient, and
orderly movement of traffic; to meet, but not exceed the needs of
the present and future population served; to have a simple and logical
circulation pattern; to respect natural features and topography; and
to create an attractive streetscape.
c)
Streets in the subdivision shall connect to and be accessible from
a public way or, with the written approval of the Planning Board,
an existing private way, which must be deemed adequate in the opinion
of the Planning Board to provide access. If the streets in the subdivision
connect to a private way, the applicant must have rights to the private
way for the purpose ways are intended and commonly used.
d)
Access. There shall be no reserve strips controlling
access to streets unless such strips are to be deeded to the Town
at the time of acceptance of the street by the Town. Reserve strips
prohibiting access to streets or adjoining property are allowed only
where required by the Planning Board along Connector or Through Streets;
and where, in the opinion of the Board, such strips are in the public
interest.
e)
The Planning Board shall be satisfied that adequate access for emergency
vehicles is provided to all of the lots in the subdivision.
f)
Access to adjoining property for pedestrian and/or bicycle circulation
shall be required wherever the Planning Board determines that such
connection will increase accessibility between adjoining subdivisions,
to existing or proposed sidewalks or bicycle paths, from subdivisions
to major public or private schools, recreation areas or other facilities
or where the public safety will be significantly enhanced by such
pedestrian and/or bicycle connections.
In order to foster compliance with the specified design speeds,
discernible and effective curvilinear street design shall be introduced
as part of the road layout so that the maximum straight length of
any portion of the proposed roadway in a residential subdivision shall
not exceed three hundred feet (300') in length. The centerline radii
of the curve shall be as close to the minimum required as is practical.
Larger radii will be discouraged.
2.
Layout standards - residential subdivisions.
a)
Wherever possible in residential subdivisions, the road system shall
be designed to serve the needs of the neighborhood and to discourage
use by through traffic. However, in major subdivisions, access shall
be designed to avoid street systems which have only one (1) principal
means of egress. In order to provide for alternative access, at least
two (2) vehicular access streets may be required by the Planning Board,
in major subdivisions when determined by the Board to be feasible.
Proposed streets within a major subdivision shall provide for their
continuation or projection to intersect with principal streets on
the perimeter of the subdivision or with adjacent vacant property
in order that the streets may be extended at a future time.
(1)
A curvilinear road layout, avoiding long straight runs, is generally
required to achieve these goals since curves tend to slow traffic
speeds and provide varied views within the subdivision.
(2)
The minimum center line radii of streets shall be one hundred fifty
feet (150'); greater radii may be required for principal streets.
The centerline radii of the curve shall be as close to the minimum
as practical. Larger radii will be discouraged.
(3)
Design speeds for residential roads shall be twenty-five (25) miles
per hour.
b)
The location of Residential Streets within the subdivision shall
be such that their use by through traffic will be discouraged. The
Planning Board may require the construction of streets to abutting
land as part of an overall plan to enhance traffic circulation in
the Town.
c)
Proposed subdivision streets shall not be located along the subdivision
boundary. If a boundary location is the only acceptable point of access,
the road must turn away as soon as practical from the boundary line
in order to mitigate any negative impact to abutters.
3.
Layout standards - commercial/industrial subdivisions. The same standards for commercial/industrial subdivisions shall
be applied as for residential subdivisions, except that wider intersections,
straighter roads, less steep slopes and other requirements designed
to increase safety and ease of access may be required by the Planning
Board.
4.
Cul-de-sacs and dead end streets. Dead-end streets without
cul-de-sacs shall not be permitted except where the Board shall find
the same to be necessary or desirable due to the small size of the
subdivision or unusual topographical conditions.
a)
Where a dead-end street is to provide access to adjacent property,
the Planning Board may require provision for a temporary circular
turn-around or 'tee' until such time as the adjacent tract
is developed and the street is extended. A bond may be required to
insure completion of the street or construction of a permanent cul-de-sac
within a reasonable period of time. Reservation of strips of land
impeding this access will not be permitted unless such land is dedicated
to the Town in conjunction with the final plat.
b)
All permanent dead-end streets shall terminate in a cul-de-sac constructed
according to these regulations. Dead-end streets shall have at their
closed end a turn-around with a minimum outside curb radius of forty
feet (40') and a right-of-way radius of fifty feet (50'). The Planning
Board may limit the length of a dead-end street where necessary to
ensure adequate and safe circulation of vehicular traffic.
c)
Where streets are terminated temporarily, and may be further extended
at a future time, a temporary cul-de-sac shall be constructed as specified
in these regulations. A defeasible easement shall be granted to the
Town for that portion of a cul-de-sac right-of-way which would be
abandoned when temporary cul-de-sac is extended.
(1)
Whenever a temporary cul-de-sac is abandoned in order to extend a
street, the developer shall remove excess pavement and curbing, landscape
such area, and install straight pavement and curbing aligned with
the rest of the roadway.
d)
For all dead-ends and cul-de-sacs, whether permanent or temporary,
an easement, which shall not be built upon or obstructed by deed,
shall be granted to the Town of at least thirty feet (30') in width
to a nearby existing street to be used for emergency access. Location
of said easement shall be determined by the Planning Board.
e)
Cul-de-sacs shall not be used as a method to gain additional lots
with reduced frontage.
5.
Street rights of way and pavement width. Streets shall
be not less than fifty feet (50') in width between property lines
and the hard surface for the traveled way shall be not less than twenty-four
feet (24'), and centered between property lines. All paved points
of access and egress from said ways to existing Town and state highways
shall not be less than thirty feet (30') wide, said thirty-foot
width to extend thirty feet (30') back from the state or Town
property line.
[Amended 1-10-2018]
a)
The Planning Board may require wider rights of way where drainage
methods used require the Town to own and maintain land beyond fifty
feet (50'). The Planning Board may permit narrower pavement widths
on dead-ends and cul-de-sacs which will never be extended or connected
to another street and where traffic, drainage and utility considerations
allow.
6.
Specific layout standards - street intersections.
a)
New street intersections should avoid being located directly opposite
existing dwellings and driveways in order to protect the residents
from headlight glare, noise, and traffic.
b)
Street intersections shall either coincide precisely with, or be
offset by at least two hundred feet (200') from other intersections.
Intersections shall be at ninety degree (90°) angles. Lesser angles
between seventy-five degrees (75°) and ninety degrees (90°)
may be approved by the Planning Board.
c)
Intersections shall not be allowed where visibility is restricted,
such as on or just below steep hillcrests or on sharp curves. Streets
shall be laid out so as to intersect as nearly as practical at right
angles. No street shall intersect any other street at less than sixty
degrees (60°).
d)
Property lines at street intersections shall be rounded with a street
line radius of not less than one half (1/2) of the wider right-of-way.
Roadway pavements at intersections or where roadways intersect circular
pavements shall be rounded with a minimum radius required for the
larger classified street at the intersection.
e)
The minimum pavement radii and centerline offsets for all classifications
of streets is shown in Table 1:
|
Table 1
| |||
|---|---|---|---|
|
Pavement Radii and Centerline Offsets
| |||
|
Street Classification
|
Pavement Radii
(feet)
|
Street Centerline Offsets
(feet)
| |
|
Local Residential Street
|
15
|
300
| |
|
Connector/Collector Street
|
20
|
500
| |
|
Through/Arterial
|
20
|
1,000
| |
|
Commercial/Industrial Connector
|
30
|
1,000
| |
f)
Three-way intersections, especially within the subdivision, will
be encouraged in order to slow traffic and minimize the possibility
of collisions. Four-way intersections are not permitted unless in
the opinion of the Planning Board public safety will not be compromised.
Street jogs shall have minimum centerline offsets from the larger
classified street as shown in Table 1.
7.
Median islands and entrance features. Where Residential
Through Streets or Commercial & Industrial Streets intersect existing
or proposed roadways, an unpaved median island and separate turning
lanes may be required. This requirement and the number of turning
lanes shall have a direct relationship to anticipated traffic movements
and volume. This requirement may be waived by the Planning Board,
if in its opinion, a median island and/or separate turning lanes are
unnecessary.
a)
If required, the median island shall extend at least sixty feet (60')
back from the intersection and be at least nine feet (9') in width
for Residential Streets and twelve feet (12') in width for Commercial
& Industrial Streets for the first thirty feet (30') back from
the intersection, then taper to two feet (2') in width (unless a continuous
median island is required). Said median island shall be identified
by signage and designed to be highly visible to oncoming traffic.
Median islands shall have granite or concrete curbing. The unpaved
median island shall consist of pervious cover such as grass, gravel,
or wood chips and shall be planted with a sufficient number of shrubs
to present a year-round visual mass. However, to maintain visibility
at the intersection, all shrubs shall not be planted closer than ten
(10) feet to the intersection. Shrubs shall be at least one and one-half
feet (1 1/2') high but not greater than three feet (3') high,
such as spreading juniper or yew.
b)
The number of turning lanes and consequently the pavement width on
each side of the median island shall be determined by the Planning
Board. Where median islands and the maximum number of turning lanes
are required, the right-of-way width at the intersection may need
to be wider.
8.
The
grade of the slopes adjacent to the paved way shall be at a ratio
of at least five (5') horizontal to one (1') vertical [twenty
percent (20%) slope - no greater]. The developer shall show cross
sections of slopes on the drawings at intervals of no greater than
fifty feet (50').
9.
Geometric data. Table 2 below shall be used as a guide
in designing local streets within a subdivision. The Planning Board
may, at its discretion, order more stringent requirements:
|
Table 2
| |||
|---|---|---|---|
|
R.O.W. Width
|
50'
| ||
|
Pavement Width (includes berms)
|
30'
| ||
|
Maximum Grades at Centerline:
|
9%
| ||
|
- Within 150' of intersections
|
2.5%
| ||
|
Minimum Grades at Centerline
|
1%
| ||
|
Minimum Radius of Curve
|
150'
| ||
|
Minimum Tangent between Curves of Centerline
|
100'
| ||
|
Minimum Sight Distance
|
200'
| ||
|
Cul-De-Sac Turnaround
| |||
|
- R.O.W. diameter
|
100'
| ||
|
- Pavement diameter*
|
90'
| ||
|
- Maximum Grade
|
4.0%
| ||
|
- Minimum Grade
|
2.0%
| ||
|
Intersection Fillet Curve
| |||
|
- R.O.W. Minimum Radius
|
30'
| ||
|
- Pavement Minimum Radius
|
25'
| ||
|
Pavement Crown
|
3.5"
| ||
|
*
|
Where approved by the Planning Board, cul-de-sacs may be designed
with a circle with a forty-foot (40') radius unpaved center.
The Planning Board will determine landscape requirements for the unpaved
center.
|
1.
General.
a)
Construction of all required improvements shall be in accordance
with all specifications set forth herein, and shall, as a minimum,
meet the construction specifications contained in Standard
Specifications for Road and Bridge Construction, published
by the State of Rhode Island, Department of Public Works, Division
of Road and Bridges, revision of 1971, and any subsequent corrections
and addenda. The following specifications for construction of streets
shall be in addition to the Standard Specifications for
Road and Bridge Construction, and shall serve to further
clarify and explain specific construction requirements in the Town
of Portsmouth. The Planning Board may, at its option, impose additional
requirements in specific situations.
b)
The developer shall, at all times during construction, ensure that
all roads in which he is installing utilities are in passable condition
and shall take appropriate measures to eliminate the creation of any
dust or erosion nuisance during construction.
c)
All construction must proceed with erosion controls in place.
(1)
Whenever construction is suspended for the winter or for any other
reason, erosion controls shall be repaired as necessary in order to
serve their intended purpose for the period of suspension.
d)
The asphalt installer must have a minimum of five (5) years relevant
experience, and be approved by the Director of the Department of Public
Works in advance.
e)
Traffic passing over constructed streets shall be limited to wheeled
vehicles. No tracked equipment shall be permitted.
f)
Prior to the construction of any building, the abutting road shall
have, at a minimum, the Binder Course installed.
2.
Road preparation. The entire right-of-way to within three
feet (3') of the right-of-way line shall be cleared and grubbed prior
to other construction, except upon approval of the Director of Public
Works. Healthy trees within the right-of-way shall be left standing
provided that the trunk is no more than three feet (3') from
the property line. All root systems, trees, stumps, bushes and other
objectionable material shall be removed and disposed off site.
a)
Earth Excavation. All earth excavations shall
conform to the lines and grades as shown on the approved final plan.
Any change in approved excavations due to unforeseen sub-surface conditions
shall first be approved by the Director of Public Works to ensure
the change does not conflict with any expressed concerns of the Planning
Board. Earth excavation shall include, but not be limited to, the
removal of clay, sand, gravel, loam, soft or disintegrated rock which
can be removed without blasting, boulders of less than one (1) cubic
yard in volume, or one-half (1/2) cubic yard in all trenches, and
other unacceptable materials within the limits of the roadway drainage,
or other excavation. Earth excavation also shall include the removal
of all stumps, backfilling of stump holes and other surface irregularities
with suitable fill materials.
(1)
Ledge and rock excavation. Rock and ledge excavations shall include
all hard rock which can be removed by drilling or splitting by hand,
by mechanical means or by blasting, and shall be removed to a depth
at least twelve inches (12") below sub-grade, and, where applicable,
ledge side slopes shall be at least four feet (4') vertical to one
foot (1') horizontal.
b)
Subsurface water. Where ground water is encountered
within three feet (3') of finished grade, adequate drainage designed
by the applicant's engineer and approved by the Director of Public
Works shall be constructed to lower ground water levels to a depth
of at least four feet (4') below finished grade within the street
right-of-way.
c)
Retaining walls. Where street and shoulder
grades require more than two feet (2') of cut or fill, retaining walls
may be required along abutting property lines unless an alternative
is approved by the Planning Board. Details to be approved by the Planning
Board.
d)
Sub-drains (on lots). Installation of conduits
such as tile, pipe, or tubing beneath the ground surface on a lot
for the purpose of diverting the ground water, to intercept or prevent
water movement into a wet area, to relieve artisan pressure, to remove
surface runoff, to serve as an outlet for other drains, or to replace
natural subsurface drainage patterns that are interrupted or discontinued
due to construction operations shall be allowed only with the written
approval of the Planning Board and the supervision by the Department
of Public Works. The location and design of lot sub-drains shall be
indicated on the drainage plan as required in Section F. of this Article,
and shall be designed according to specifications contained in the
Rhode Island Erosion and Sediment Control Handbook, 1989, as amended.
3.
Materials. Depth of materials shall be measured after
thorough compaction.
a)
Base course. The Base Course shall consist
of twelve inches (12") bank run gravel borrow which conforms to the
requirements of Subsection M.01.09 Table I, Column I of the RI Standard Specifications plus the following:
(1)
It shall be practically free from loam, silt, clay and vegetable
matter.
(3)
At least fifty percent (50%) by weight of the gravel shall be of
the sizes retained upon a one-quarter inch (1/4") sieve.
(4)
Not over thirty-five percent (35%) of the particles passing a one-quarter
inch (1/4") sieve shall pass a No. 40 mesh sieve.
(5)
Not more than ten percent (10%) of the particles passing a one-quarter
inch (1/4") sieve shall pass a No. 200 mesh sieve.
(6)
Recycled asphalt or recycled concrete may be used in the base course
only with the written approval of the Director of Public Works, who
may stipulate material and installation specifications, and who may
require an analysis of material installed.
b)
Base Surface. The Base Surface shall consist
of processed gravel a compacted depth of two inches (2") of crushed
Bank Run Gravel with a foreign content of not more than fifteen percent
(15%), which conforms to the requirements of Subsection M.01.09. Table
I, Column II of the RI Standard Specifications.
c)
The Binder Course shall consist of two inches
(2") of Bituminous Concrete Pavement (hot mix) Class 12.5 conforming
to the requirements of Section 401 of the RI DOT Standard
Specifications For Road and Bridge Construction.
[Amended 1-10-2018]
d)
The Surface Course shall consist of one-and-one-half
inches (1 1/2") of Bituminous Concrete Pavement (hot mix) Class
9.5 conforming to the requirements of Section 401 of the RI DOT Standard Specifications For Road and Bridge Construction.
[Amended 1-10-2018]
4.
Construction methods.
a)
Sub-base. All underground sewer and water
lines, utilities, laterals, service lines and related facilities shall
be installed prior to any street construction. Following filling and
compaction of all utility trenches, the sub-base shall be thoroughly
compacted with a ten (10) ton roller or its equivalent as necessary
to achieve ninety-five percent (95%) compaction, true to the lines,
grades and cross sections shown on the approved drawings, and all
subgrades shall be shaped on lines parallel to finished road surface.
Said rolling shall provide a stable and unyielding base. All soft
spots shall be excavated to firm material and brought to subgrade
with gravel or other approved material.
b)
Manholes and catch basins - All manholes,
catchbasins and other underground utility access from the street surface
shall initially be installed so that their tops are at Binder Course
grade level, then raised to the level of the surface course upon the
installation of the surface course.
c)
Base course. Bottom inspection is required
before placing gravel. Grade stakes with elevation shall be in place
and approved by the Director of Public Works prior to installation
of gravel. Grades shall be as shown on the approved final plans. Deviations
from said elevations may be approved in writing only by the Director
of Public Works. After the sub-base has been properly prepared and
the curbs or shoulders set, the Base Course of bank run gravel shall
be spread for the full width and in such volume as to provide a twelve-inch
(12") cross section after compaction with a ten (10) ton roller or
equivalent.
d)
Base surface. Following thorough compaction
of the Base Course, processed gravel shall be spread for the full
width and in such volume as to provide a two inch (2") cross section
after compaction with a ten (10) ton roller or equivalent.
e)
Binder course. The Binder Course shall consist
of an application of Bituminous Concrete Pavement (hot mix) Class
I, Type I-1 applied as follows:
(1)
The Base Surface shall be clean of all debris,
protrusions shall be removed from any holes, ripples or unevenness
in the surface shall be brought back to true line and cross section,
prior to Binder Course application.
(2)
The Binder Course shall be applied at a temperature
of two hundred fifty (250°) to three hundred fifty degrees (350°)
Fahrenheit by means of an approved paving spreader. Such material
shall be placed in sufficient quantity to provide a minimum compacted
cross section of one and one-half inches (1 1/2").
(3)
Compaction. The Binder Course shall be compacted
as specified in Section 401.03.11 of the RI Department
of Transportation Standard Specifications.
(4)
Six (6) months after the application of the binder course, if the
surface course has not been installed, the binder course shall be
vacuum swept clean and a continuously machine applied spray type tack
coat shall be applied over the binder course and an emulsion over
all curbs and seams, with the approval of the Director of Public Works.
f)
Surface course. The surface course shall be
installed no later than six (6) months after the binder course is
completed, and after inspection and approval by the Director of Public
Works. The surface course shall consist of an application of Bituminous
Concrete Pavement (hot mix) Class I, Type I-1, applied as follows:
(1)
The Binder Course shall be vacuum swept clean
of all sand and debris, ripples or unevenness in the surface shall
be brought back to true line and cross section by the spot application
and proper compaction of Class I mix.
(2)
The Surface Course shall be applied at a temperature
of two hundred fifty (250°) to three hundred fifty degrees (350°)
Fahrenheit by means of an approved paving spreader. Such material
shall be placed in sufficient quantity to provide a minimum compacted
cross section of one and one-half inches (1 1/2").
(3)
Compaction. The surface course shall be compacted
as specified in Section 401.03.11 of the RI Standard Specification.
Upon completion of the application and compaction of the Surface Course,
the street shall be allowed to stand for a minimum of eight (8) hours
without traffic.
(4)
The finished surface shall have a minimum cross-slope of 0.024 (1/4")
per foot.
g)
Curbing. There shall be constructed at the
time of the installation of the binder course and again at the surface
course a monolithic (or integral) paved "Cape Cod" berm of twelve
inches (12") wide on each side of the road. The outside elevation
of the berm shall be two inches (2") above road crown elevation.
(1)
Slope faced precast concrete or granite curbing meeting RI DOT Standard
7.21 may be required at intersection fillet curves in lieu of extruded
Cape Cod curbing. Precast or poured concrete wheelchair ramp curbs
meeting RI DOT Standard 7.19 shall be installed in areas of frequent
pedestrian use as required by the Director of Public Works.
h)
Seasonal limits. No bituminous material shall
be laid when the temperature of the area is under or likely to fall
under forty degrees (40°) Fahrenheit during the following twenty-four
(24) hours or during other unfavorable weather conditions, as may
be determined by the Director of Public Works.
1.
General. Subdivision proposals shall be reviewed to determine
whether such proposals will be reasonably safe from flooding. If a
proposed subdivision is in a flood-prone area, such proposal will
be reviewed to assure that (a) it is consistent with the need to minimize
flood damage within the flood-prone area, (b) all public utilities
and facilities, such as sewer, gas, electrical and water systems are
located and constructed to minimize or eliminate flood damage, and
(c) adequate drainage is provided to reduce exposure to flood hazards
by ensuring, at a minimum, that there will be no net increase
in the peak discharge rate of stormwater runoff from the site.
a)
The Planning Board may, at its discretion, require that the rate
of runoff be decreased from the condition existing prior to subdivision
development.
b)
If a detention or retention of water is required by the Planning
Board, the detention/retention areas shall be completed prior to placement
of any pavement in the subdivision. The bottom of all retention, detention,
sediment ponds, flood control holding and similar facilities shall
be a minimum of twenty-four inches (24") above the seasonal high water
table. If a development is to be phased or roadways to be constructed
sequentially per an approved Construction Sequence, then drainage
facilities sufficient to handle each phase or road section shall be
completed prior to placement of any pavement in said phase. In no
case shall construction of any improvements be permitted until suitable
and adequate drainage facilities to accommodate said construction
are functional and inspected.
[Amended 4-29-1998[1]]
[1]
Note: Changed 4-29-1998 from '(b) If a detention or retention
of water is required by the Planning Board, the detention/retention
areas shall be completed prior to construction of any improvements
in the subdivision. The bottom of all retention, detention, sediment
ponds, flood control holding and similar facilities shall be a minimum
of 24" above the seasonal high water table.'
c)
Calculations, design and methods shall be done by a registered professional
civil engineer in accordance with the Rhode Island Stormwater
Design & Installation Standards Manual, 1993 as amended.
d)
All stormwater facilities shall be protected from the buildup of
sediment by use of hay bales or filter screens during construction,
and cleaned out prior to release of bonds.
2.
Drainage plan - general.
a)
At the preliminary plan stage, the applicant shall establish that
adequate provision is made for the disposal of surface water without
significantly increasing flood hazards or creating conditions harmful
to the proposed development or to the adjacent or nearby land and
property. Within public water supply watershed areas, the drainage
plan shall also show measures to ensure that the public water supply
quality is protected. Plan shall provide for adequate and sufficient
drainage facilities throughout the course of construction and development.
[Amended 4-29-1998[2]]
[2]
Last sentence added 4-29-1998.
b)
The applicant shall submit all computations in determining pre-development
and post-development rates of storm water runoff to the Planning Board
at the preliminary review, as further detailed in Subparagraph 3 below.
The Planning Board may forward the computations to a review agency
or official for verification and review prior to approving the subdivision.
These computations shall be based upon an analysis of peak discharge
from a two (2), ten (10), and twenty-five (25) year frequency, twenty-four
(24) hour duration, type III[3] distribution storm, and shall use the methodology contained
in a report entitled Urban Hydrology for Small Watersheds, Technical Release No. 55 (Second Edition) USDA, Soil Conservation
Service, 1986, and any subsequent amendments thereto. Where the use
of the above report is not practical for reasons based on accepted
engineering practice, the Planning Board may permit the use of alternate
methodologies for calculating storm water discharge. Provided, however,
that such alternate methodologies shall be made at the time of application
for a Master Plan review. All computations shall be prepared by a
professional civil engineer registered in the State of Rhode Island
and the engineer's seal shall be affixed to all required documents.
[Amended 4-29-1998]
[3]
Changed 4-29-1998 from type II.
c)
The runoff management systems, a single component or a combination
of components, must properly regulate storm discharges from the site
to any outlet capable of handling the designed stormwater discharge
without increasing downstream or off-site flooding, draining, soil
erosion or other runoff related problems to public or private land,
facilities, or water resources. Provision shall be made for maintenance
of all components of the runoff management systems prior to approval
of the subdivision.
d)
Drainage plan must consider all runoff from lots to be developed,
as well as to and from adjacent property. The grading of lots shall
not be designed to excessively drain onto road surfaces. No pumping
of stormwater or groundwater onto road surfaces shall be permitted.
3.
Contents of drainage plan. A drainage plan prepared by
a registered professional civil engineer shall be submitted with the
preliminary plat material. It shall contain all elements required
in the "Drainage and Sediment Control Measures Checklist" attached
hereto according to the following:[4]
a)
Topographic map at a suitable scale of the area within a half-mile
of the perimeter of the land being subdivided showing all existing
and proposed floodplains, watercourses and floodways, wetlands, storm
drains, culverts and all surface and subsurface drainage patterns
from the property being subdivided to the ultimate discharge point
of the watershed.
b)
An estimate of the rate and quantity of storm water surface run-off
presently flowing from the land proposed to be subdivided and that
which would be generated by the proposed subdivision, calculated on
the basis of a twenty-five (25) year frequently rainfall. Due to the
prevailing soils types in Portsmouth, computations shall include consideration
of all impervious surfaces to be created throughout the fully built-out
subdivision, including roads, sidewalks, driveways and building.
c)
The stormwater drainage calculations, runoff rates and system design
shall be based on the application of the appropriate method as follows:
(1)
The Rational Method. This method is the preferred
method for small systems of three (3) acres or less, where no wetlands,
ponds, or other storage depressions are present, and where drainage
is toward the point of analysis.
(2)
TR-55. This is the preferred method for calculating
runoff volumes, peak discharge rate, and flood storage requirements
for site development between one (1) acre and two thousand (2,000)
acres.
(3)
TR-20. This is for large complex watersheds
and systems beyond the scope of TR-55.
d)
An analysis of the capability of existing and proposed watercourses,
storm sewers, culverts and other drainage facilities within the land
proposed to be subdivided to handle the run-off as calculated under
(2) above, and the effect upon floodways and flood holding capacity
of any floodplains.
e)
Proposals for disposal of surface water run-off, downstream from
the subdivision without damage to land and improvements.
f)
The drainage plan shall further indicate how the following specific
requirements shall be met:
(1)
That each lot shall be adequately drained.
(2)
That natural drainage patterns will be maintained whenever possible.
(3)
That all existing watercourses will be left open, unless approval
to enclose is granted by the Planning Board and RIDEM.
(4)
That all new open watercourses will be seeded, sodded, or protected
with stone rip rap depending on grades and soil types.
(5)
That an adequate drainage system shall be installed and connected
after treatment to a defined and approved watercourse, and is designed
so as to accommodate flows resulting from up to a twenty-five (25)-year
frequency storm.
(6)
Where any part of the drainage system is proposed for location outside
the public street right-of-way, provisions for future maintenance
approved by the Planning Board shall be provided.
(7)
That there is or will be adequate access for Town maintenance vehicles
to all drainage and stormwater facilities. That all necessary easements
to off-site watercourses will be obtained by the applicant and granted
to the Town of Portsmouth.
[4]
Editor's Note: The Drainage and Sediment Control Measures
Checklist is included as an attachment to this chapter.
4.
Drainage easements. The Planning Board may require, whenever
necessary, the provision of an easement of a suitable width across
any portion of the land being subdivided for the purpose of providing
adequate drainage. Such easement shall guarantee access to the Town
of Portsmouth to or along any proposed storm water drainage facility
or watercourse and shall guarantee the right to construct, maintain
or alter any such facility. See also Section M herein.
5.
Detention/Retention pond safety, fencing and screening. Detention/Retention ponds capable of holding water to a depth of
twenty-four inches (24") or more for a period of twenty-four (24)
hours or more shall be enclosed by a five foot (5') high green vinyl
clad chain link fence, unless the Planning Board deems otherwise.
All slopes shall be no greater than 3:1. The Planning Board, at its
discretion, may require additional vegetative screening, particularly
where such ponds are regularly visible from nearby residences.
6.
Evaluation of drainage plan-by Board.
In the preparation of a Drainage Plan, the applicant is encouraged
to consider measures or construction techniques that can be used to
control peak discharges from the development through planned run-off
delay and infiltration into the ground. The Planning Board will consider
the character of the area being developed, existing ground cover,
the likelihood of damage due to flooding and the character of nearby
properties. At the preliminary plat stage, it will indicate whether
measures to reduce either the volume or the rate of run-off are necessary
to achieve desired objectives.
The Board may, after its review of the proposed drainage plan,
require that the following provisions apply:
a)
Future-condition storm water run-off discharge do not exceed present
condition discharges into the floodway as calculated up to a twenty-five
(25)-year frequency storm.
b)
Development be prohibited within the floodway which will result in
any increase in flood levels during the occurrence of a twenty-five
(25)-year frequency storm discharge.
c)
That there is no reduction in the holding capacity of the one hundred
(100)-year flood plain.
d)
All construction of drainage and flood protection systems and all
development within areas subject to flooding are adequately designed
so as to withstand a one hundred (100)-year frequency storm.
e)
Every lot be located so as to provide an area for construction of
a residential building which is not within a river line floodway.
7.
Storm drain piping, catchbasins, and manholes.
Any connection to an existing public storm drainage system shall
be allowed only with the approval of the Planning Board and the Director
of Public Works, as applicable.
All necessary surface and sub-surface storm drainage structures
and facilities shall conform to the R.I. Standard Specifications for
Road and Bridge Construction. Such Standard Specifications may be
modified at the discretion of the Planning Board.
The Planning Board may require that surface and sub-surface
storm drainage pipes and facilities be installed and connected to
dry wells or watercourses, to retention or holding ponds, or to an
existing public storm drainage system.
a)
Drainage pipes.
(1)
All pipes shall be reinforced concrete with gasketed seals. Minimum
pipe size shall be twelve inches (12") in diameter for laterals and
eighteen inches (18") in diameter for all other drainage pipes.
[Amended 4-29-1998[5]]
[5]
Note: Changed 4-29-1998 from '(1) All pipes shall be
reinforced concrete with gasketed seals. Minimum pipe size shall be
12" in diameter.'
(2)
Where pipe culverts are required across private drives, the applicant
shall furnish and install said culverts and provide drives or roads
to the road or highway.
(3)
All drainage lines are to be saw cut, so as to be flush with the
inside surface of the catch basin.
(4)
Excavation, fill and compaction. Compaction
shall be in accordance with R.I.D.O.T. Standard Specifications for
Road and Bridge Construction. The installation of the pipe shall be
surrounded in six inches (6") of clean broken stone which shall be
at least one-quarter inch (1/4") and not more than one and one-half
inches (1 1/2") in size. The pipe shall be laid true to line
and grade, and joints sealed with a commercial gasket approved for
drainage pipe used.
(a)
In the event that groundwater is encountered during excavation
the drainage trench shall be excavated only as fast as the pipe can
be installed, with the bottom of the trench being excavated six inches
(6") below the elevation at which the pipe will be laid.
(5)
Minimum cover. All subsurface storm drainage
pipes within street rights-of-way shall have a minimum cover of three
feet (3'). All drainage structures and facilities shall be inspected
and approved by the Director of Public Works before covering.
b)
Manholes and catch basins. Catch basins shall
be R.I. Standard 4.31 Type "R" or as directed by the Director of Public
Works.
(1)
Storm Drain Manholes or Catch Basins shall be located:
(a)
At maximum separation of two hundred feet (200');
(b)
At all angles in the storm sewer line;
(c)
At all existing and new street intersections and all points
where catch basins, inlets or laterals are to be connected;
(d)
At points where pipe sizes change;
(e)
At points where the grade of the storm sewer changes;
(f)
At the bottom of any hill or other significant slopes over ten
percent (10%).
(2)
Notwithstanding State specifications, all catch basins and manholes
shall be of pre-cast concrete with neck for frame and cover, and equipped
with gaskets at all entrances. Frames and covers shall be as specified
by the DPW. Larger catch basins may be required by the Director of
Public Works and approved by the Board.
(3)
In the event that a catch basin is over six feet (6') deep, metal
rungs three-quarters inch (3/4") thick shall be set in the side of
the basin approximately twelve inches (12") to eighteen inches (18")
apart or as directed by the Director of Public Works.
(4)
All manholes, catch basin and other underground utility access from
the street surface shall initially be finished to be level with the
surface of the binder course, then raised to the level of the surface
course upon the installation of the surface course.
(5)
Cleanout. Piping manholes and catch basins shall be installed as
required and cleaned out prior to release of bonds.
(6)
Where drainage pipes are forty-eight inches (48") or larger, catch
basins shall be approved by the Planning Board.
(7)
All outgoing catch basin inverts shall be at least three inches (3")
or twenty-five one-hundredths feet (0.25') lower than incoming catch
basin inverts.
1.
A
plan meeting the requirements of the Portsmouth Soil Erosion and Sediment
Control Ordinance[1] must be filed and approved prior to subdivision preliminary
approval for a major subdivision, and before final approval for minor
subdivision.
2.
All
erosion and sediment controls shall be in place prior to the start
of construction. Such controls shall be placed to minimize the flow
of sediment onto other properties and into catch basins. All catch
basins, sediment ponds, hay bales and other structures which may have
collected sediment shall be cleaned out after the binder course is
approved and prior to release of securities posted to guarantee proper
installation of public improvements.
3.
The
Planning Board may require the following measures to be employed where
necessary, and shall be shown upon preliminary subdivision plans:
a)
Sediment in run-off water shall be retained on the site insofar as
possible by the use of debris basins, sediment basins, silt traps,
or similar measures.
b)
Stripping of vegetation, regrading, cut/fill operations, and extent
of disturbed areas shall be kept to a practical minimum. Temporary
vegetation and/or mulching shall be used to protect exposed critical
areas during development.
c)
Natural slopes and existing contours shall be retained insofar as
possible when locating streets, drainage and structures. No grading
or siting shall create conditions which would create insufficient
drainage or the likelihood of soil erosion.
d)
Grading plans for individual lots in the subdivision may be required
by the Planning Board where it feels there is a reasonable likelihood
of erosion, drainage or siting problems.
e)
Lot slopes. No earth, gravel or sand slope shall exceed a three (3)
horizontal to one (1) vertical ratio without the use of cribbing,
a retaining wall or similar structure.
f)
Where the volume and/or velocity of the surface water run-off is
high, discharge points shall be adequately protected against erosion
or scour.
There shall be filed with the preliminary plat a plan and profile
of all contemplated underground utilities and construction. All electricity
and gas lines, street lighting lines, telephone, cable and other communication
lines shall be installed underground. In cases where underground installation
is not feasible due to the physical condition of the site or other
limiting factors, an alternative location for these lines, including
above ground, may be approved by the Planning Board.
1.
Physical location.
a)
Electrical, Lighting and Communication Utilities shall be located
in the west and south shoulders of the street right of way. Such facilities
shall be located five feet (5') from the property line and shall have
thirty-six inches (36") of cover.
b)
Gas facilities shall be located in the north and east shoulders.
In general, they shall be located seven feet (7') from the property
line. Gas lines shall be installed at a depth of sufficient to require
thirty-six inches (36") of cover.
c)
Water mains shall be located in the north and east shoulders off
the paved roadway, as determined by the public water supply agency.
In general, they shall be located four feet (4') from the property
line.
d)
All utilities shall be marked one foot (1') above the individual
utility with a metallic marking tape.
2.
Installation.
a)
Installation of all underground utilities shall be performed according
to the rules and regulations of the appropriate utility company. Prior
to preliminary approval of any subdivision the applicant shall furnish
a letter from the appropriate utility companies indicating concurrence
with the plan for installation of the utility.
b)
All backfill and compaction for excavations which are located or
may be located under road pavements shall be compacted in six inch
(6") lifts by mechanical means such as tamping, or by puddling or
jetting to a minimum of ninety-five-percent (95%) compaction.
c)
Utility Manholes shall be of pre-cast concrete with neck for frame
and cover. Frames and covers shall be as specified by the utility
companies.
d)
All utilities shall be installed, inspected and approved prior to
the installation of the binder course of road pavement.
3.
Any
deviation from these requirements shall be approved in writing by
the Public Works Director.
4.
Each
public utility company shall supply the other public utility companies
with an "as built mylar plan" of their facilities.
Each public utility company shall also supply the Director of
Public Works and the Planning Board with one (1) copy each of the
above mentioned "as built mylar plans".
5.
Street lighting. The developer shall provide for street
light installation as recommended by the responsible public utility
company and approved by the Planning Board. These regulations are
not intended to install street lighting until approved by the Town
Council. For each street light not installed, prior to release of
the bond, the developer shall deposit with the Finance Director a
fee commensurate with that installation. The Public Works Director
will then be responsible for installation of the light at the appropriate
time.
6.
Public water supply.
a)
Public water in Portsmouth is provided by either the Portsmouth Water
and Fire District, the Newport Water Department, or the Prudence Island
Utilities Corporation. In subdivisions situated within a water district
or water company franchise area, water mains and water services to
each lot or building site shall be installed as approved by the public
water authority. Where the public water authority does not approve
installation of water mains and water services to each lot or building
site, conduits for such possible future water supply shall be installed
to avoid future road excavations. Specifications for installation
of public water supply lines shall be determined by the applicable
agency. Approval of plans for the installation of public water supply
lines, if any, shall precede final approval or recording of any plat
by the Planning Board. Inspection of installed water lines shall be
done by the appropriate water supply agency, notification of which
shall be as provided in Section N herein.
b)
Water mains in any subdivision shall be located off the paved roadway.
Where water mains or conduits are installed in any subdivision, the
water service or conduits shall be installed from the water main to
each and every lot which is on the side of the road in which the main
is not installed, before any roadway pavement or surface is installed.
c)
Fire Hydrant location and maximum spacing, the number of hydrant
ports and thread type shall be approved by both the public water authority
and the Chief of the Fire Department, according to their regulations
and practices.
d)
Detailed plans for the installation of public water mains and hydrants
shall be reviewed and approved by the appropriate public water authority
prior to the approval of the preliminary and final plans by the Planning
Board. Said approved plans shall be submitted to the Administrative
Officer and the applicant's civil engineer shall certify that
subdivision plans and water supply plans coincide.
(1)
No final plan shall be approved or recorded without sufficient evidence
of approval by the appropriate public water authority, unless the
applicant certifies in writing that the development will not be served
by public water.
7.
Coordination. It shall be the applicant's responsibility
to ensure that the Town and the appropriate utilities agree to the
same set of plans and coordinate their inspection activities.
1.
All
street names must be submitted to the Fire Department for preliminary
approval and evidence of such preliminary approval shall be submitted
to the Planning Board for final approval.
2.
The
developer shall furnish and install street name signs at all street
intersections. Traffic control signs such as "Stop", "Slow Children",
"No Parking" and their locations shall be specified by the Chief of
Police and recorded in the NOTES section of the plans.
a)
Street name and traffic control signs with supports, of a type acceptable
to the Director of Public Works shall be provided and erected by the
applicant at each street intersection in the subdivision.
b)
A portion of the Performance Bond shall be retained until street
signs are erected.
c)
As an alternate, for each sign not installed, prior to release of
the bond the developer shall deposit with the Finance Director a fee
commensurate with that installation. The Director of Public Works
will then be responsible for installation of the sign(s) at the appropriate
time.
[Amended 1-10-2018]
A landscaping plan as required under this section shall be conceived
in a total pattern throughout the site, integrating the various elements
of site design, preserving and enhancing the particular identity of
the site and creating a pleasing site character. Landscaping may include
plant materials such as trees, shrubs, ground covers, grass, flowers,
etc., and may also include other materials such as rocks, stone walls,
paving materials, planters, signage, and street furniture.
1.
Landscape plan.
a)
Applicability: A landscape plan shall be submitted
to the Planning Board for all land development and subdivision applications
subject to their approval at the preliminary review stage of minor
subdivision or land development plan and at the master plan stage
of a major subdivision or land development plan.
b)
Submission contents:
(1)
The plan shall indicate the location of all proposed landscaping
including construction details and identify existing and proposed
features such as:
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Trees;
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Shrubs and ground covers;
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Natural features such as stone walls and rock outcroppings;
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Man-made elements such as retaining walls, fences, signs, planters,
underground and overhead utility lines, etc.;
|
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•
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Proposed grading at two-foot contour intervals;
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Lighting;
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Specifications for loaming, fertilizing and seeding; and
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•
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Other proposed landscaping elements as required under this article.
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(2)
A planting schedule shall be included to indicate proposed planting
by species, size at time of planting and maintenance requirements.
Where existing plantings are to be retained, the plan shall indicate
proposed methods of protecting them during construction.
2.
Landscape design standards.
a)
Location. The type and amount of landscaping
required shall be allowed to vary with type of development. Areas
which may be required to provide landscaping shall include, but are
not limited to, the following:
(1)
Drainage facilities, such as retention/detention basins, or drainage
swales;
(2)
Entrance features;
(3)
In public areas;
(4)
Adjacent to buildings;
(5)
Open space areas;
(6)
Proposed recreation facilities;
(7)
Buffer areas;
(8)
Lot areas which are disturbed during the construction process or
where extensive grading removes a significant amount of natural vegetation;
or
(9)
Areas subject to regrading or stabilization for soil erosion and
sediment control purposes for soil stabilization.
b)
Election. The plant or other landscaping material
that best serves the intended function shall be selected. Landscaping
materials shall be appropriate for the local environment, soil conditions,
and availability of water. The use of grasses that require minimal
watering and fertilization is encouraged, particularly in areas that
are ecologically sensitive.
c)
Maintenance. Ongoing maintenance of landscaping
shall be a continuing requirement of compliance with the regulations.
For large projects, or significant landscape features, a minimum two-year
maintenance agreement and/or bond may be required.
3.
Street trees.
a)
Purpose. The Town of Portsmouth recognizing
the value of trees in preserving the aesthetic and environmental qualities
of the community. It is the purpose of this subsection to promote
and protect the public health, safety and general welfare by providing
for the regulation of the planting, maintenance and removal of street
trees within the Town of Portsmouth.
b)
Location. Street trees shall be planted within
proposed lots on private property paralleling street or travelled
way;
c)
Spacing. Street trees shall be planted at
intervals of no more than fifty feet (50') apart.
d)
Species selection. Street tree species selection
shall be selected based upon the following criteria:
(1)
No species shall be selected that are listed in the "Invasive Plant
Atlas of New England" (https://www.eddmaps.org/ipane/);
(2)
For guidance on planting species selections refer to "Planting and
Maintaining Sustainable Landscapes: A Guide for Public Officials and
the Green Industry," Barnstable County and University of Massachusetts
Extension, 2008 (available for reference at the Portsmouth Public
Library or the Building Department Office at Town Hall);
(3)
Species shall be selected that are suitable for their intended locations
and service;
(4)
Low-maintenance and disease-resistant species shall be selected that
do not require watering or fertilizers following the care after initial
planting; and
(5)
A variety of diverse species shall be selected to safeguard against
vulnerability from pest infestation, weather events, invasive species
and climate change.
g)
Tree Warden. Species and locations shall be
subject to approval by the Portsmouth Tree Warden.
Under certain conditions the Planning Board may require the
installation of sidewalks where pedestrian traffic is likely, such
as near schools, playgrounds, shopping areas, or high traffic volume
streets. Location, width and specifications to be set by the Planning
Board.
Easements may be required by the Planning Board where necessary
for the proper location and placement of improvements on private land
as described below. The Board may, in its own discretion, require
the dedication of land to the Town in lieu of easements if such dedication
would provide greater control over and access to the intended use.
All easements shall be duly recorded with metes and bounds and legal
description. Easements may be required for:
1.
Water line easements. Easements across lots or on rear
or side lot lines shall be provided for public water mains where required
for looping of the water system, as determined by the public water
authority. The Planning Board may require, as advised by the public
water authority, permanent easements plus temporary construction easements.
The nominal width for water line easements shall be twenty feet (20').
2.
Drainage easements. Easements to install and maintain
underground drainage facilities on private land shall be dedicated
to the Town where required. The nominal width for such a drainage
easement shall be twenty feet (20'). Where above-ground drainage flows
are directed over private property which does not contain natural
watercourses or wetlands, or where publicly owned and maintained drainage
systems outfall on private land, a drainage easement shall be dedicated
to the Town over the area and at a location adequate for the intended
purpose. Easements into and upon aboveground drainage facilities such
as stormwater detention or retention basins shall be granted to the
Town wherever stormwater from Town-owned streets or other improvements
is intended to be directed to such basins.
a)
Any required road drainage easements or right of way recommended
by the Director of Public Works shall be approved by the Planning
Board and obtained by the applicant and be not less than twenty feet
(20') wide. Easement piping to be no greater than five feet (5') from
the center line of the easement.
3.
Grading easements. The Planning Board may require the
dedication of an easement to the Town in order to grade or to maintain
grading on private property where such grading is necessary to establish
or maintain adequate drainage, sight distances, or topographic features
required as a condition of subdivision approval.
4.
Sight distance easements. Where deemed necessary by the
Planning Board to establish or maintain adequate sight distances for
vehicular traffic, the dedication of an easement to the Town may be
required which would prohibit the erection or maintenance of any visual
obstruction.
5.
Bicycle or pedestrian access easements. Bicycle and pedestrian
access shall be provided, where required by the Planning Board, on
a separate strip of land dedicated to the Town or on an easement having
a minimum width of ten feet (10').
6.
Other easements. At the discretion of the Planning Board,
all other required easements shall be of sufficient width and area
for the intended purpose. All utility easements shall be a minimum
width of twenty feet (20') and contain at least one (1) concrete bound.
Utilities shall be located on the centerline of all easements.
1.
Every
preliminary and final plan shall show the proposed location and nature
of all permanent monuments.
2.
Placement and installation.
a)
Monuments shall be placed by a Registered Land Surveyor on the street
line at the beginning and end of all horizontal curves on both sides
of each subdivision (public) street and shall not be more than five
hundred feet (500') apart.
b)
Monuments shall be of granite or concrete, at least thirty-six inches
(36") long, and set flush with the finished grade of the landscaped
shoulder.
c)
Monuments shall be installed, before the performance bond is released,
in accordance with practices set forth by the R.I. Board of Professional
Surveyors.
Each phase or step in the construction of required improvements
listed below shall be inspected and approved, in writing, on the site
by the Director of Public Works or his representative. No subsequent
phase or step shall commence until such inspection and approval of
the prior phase or step has been completed. The following procedures
shall be followed by the subdivider and by contractors under the direction
of the subdivider in the construction of any subdivision or related
improvement:
1.
Pre-construction meeting. A pre-construction meeting
shall be held with the Director of Public Works, the Administrative
Officer,[1] and the inspector, if any, hired by the Town to inspect
the job at least seven (7) days prior to the start of any subdivision
improvements. The subdivider (or his duly authorized representative)
and the on-site project manager shall attend this meeting.
[Amended 4-29-1998]
[1]
Note: Added 4-29-1998.
2.
Request for inspection. Whenever an inspection is required
the developer shall request the Director of Public Works to make such
inspection. The Director of Public Works or his representative shall
within forty-eight (48) hours exclusive of Saturday, Sunday and holidays,
make such inspection and give to the developer written approval or
disapproval of the improvements inspected by him. No subsequent step
or phase shall commence until an inspection has been made and approval
granted.
3.
Mandatory inspections.
a)
During and following installation of all underground drainage and
utilities, prior to backfilling.
b)
During and following preparation of the sub-base, backfilling and
the installation of curbing or shoulders, prior to the application
of the base course. A compaction test by a competent independent inspection
lab shall be provided after the installation of the sub-base, in locations
determined by the Director of Public Works. Bottom inspection is required
before placing gravel. Grade stakes with elevation shall be in place
and approved by the Director of Public Works prior to installation
of gravel.
c)
During and following spreading and compaction of the base course
of the roadway, prior to the application of
the binder course.
d)
Immediately prior to and during the application and compaction of the surface course on the roadway
and sidewalks. A bore core by a competent independent inspection lab
shall be provided after the installation of the surface course, in
locations determined by the Director of Public Works.
e)
During and following completion of all improvements and installation
of monuments.
f)
At periodic intervals as required to ensure compliance with the approved
Erosion and Sediment Control Plan.
g)
Final Inspection immediately prior to release of any and all bonds
or portions thereof.
4.
Additional inspections. The Planning Board, as part of
its approval conditions, or the Director of Public Works, at their
discretion, may require inspection at such other intervals or for
installation of other improvements which they may deem necessary to
assure proper construction and installation of improvements.
5.
Field verification. Notwithstanding the provisions of
this Article, the developer's engineer shall be responsible for
verifying all field elevations and grades, plus locations of manholes,
underground utilities and piping. The developer's engineer shall
be responsible for ensuring that construction is done in accordance
with the approved plans and specifications, as well as the requirements
of these regulations. The developer's engineer shall submit reports
on the progress of construction to the DPW Director, with copy to
the Administrative Officer, as reasonably required by the DPW Director,
not less than weekly and at critical junctures as directed at the
preconstruction meeting.
[Amended 4-29-1998[2]]
[2]
Note: Last two sentences added 4-29-1998.
6.
Inspection authority. The Director of Public Works shall
have the authority to issue a "cease and desist order" on construction
of required improvements if he finds that work is not being done in
a satisfactory manner or according to approved plans. The results
of all inspections shall be reported to the Planning Board in writing.
1.
Definition and purpose.
An improvement guarantee is a security instrument
accepted by the Town to ensure that all improvements, facilities,
or work required by these Regulations or as a condition of approval
of a subdivision plan by the Planning Board will be completed in compliance
with the approved plans and specifications.
Improvement guarantees shall be provided to ensure the proper
installation and maintenance of required street, utility, drainage
and other physical improvements and to ensure compliance with other
nonstructural conditions of final plat approval (if any). The nature
and duration of the guarantee shall be structured to achieve this
goal without adding unnecessary costs to the subdivider.
2.
General procedures. Before any land development or subdivision
plan is endorsed by the Planning Board, and before the recording of
any subdivision plats, the Planning Board shall be required to approve
agreements for the completion of all required improvements.
a)
The provisions of Subparagraphs 3 through 6 of this Article, below,
shall apply for financial guarantees of public improvements.
b)
Improvements that are proposed to be privately owned and maintained,
such as, but not limited to, streets, utilities, and drainage systems,
may be covered by an improvement guarantee if required by the Board.
3.
Procedures for financial guarantees.
a)
Amount.
Improvement guarantees shall be in an amount sufficient to cover
all costs and conditions to secure for the Town the actual construction
and complete installation of all of the required improvements for
active subdivisions or phases thereof as appropriate, and the satisfactory
completion of all conditions of final approval within the time periods
required for completion provided in Subparagraph b) of this subparagraph
below. The amount of the bonds shall be set by the Planning Board.
If the subdivider disagrees with the amounts, he/she shall have the
opportunity to submit a detailed estimate along with supporting justification
for the proposed revisions. The Board may set the guarantee in a reasonable
amount in excess of the estimated costs in order to anticipate for
increases in economic or construction conditions.
[Amended 4-29-1998]
|
At the expiration of the final plan approval period, if all
required improvements are not complete, the Planning Board shall review
the status of improvements and may (1) require the subdivider to extend
the duration of the entire improvement guarantee; (2) reduce the amount
of the improvement guarantee to cover the estimated costs of remaining
improvements; or (3) authorize the Administrative Officer to take
the steps necessary to ensure completion of the remaining work by
using improvement guarantee funds.[1]
| |
|
If at any time during the guarantee period the procedures, implementation
measures, methods, materials, and/or schedules of construction are
determined by the Planning Board not to be in compliance with the
approved plans, the Board may, after proper notification to the subdivider,
authorize the use of improvement guarantee funds to ensure proper
compliance.
|
[1]
Note: Changed 4-29-1998 from 'a) Amount Improvement guarantees shall be in an amount sufficient to cover
all costs and conditions to secure for the Town the actual construction
and complete installation of all of the required improvements, and
the satisfactory completion of all conditions of final approval within
the time periods required for completion provided in subparagraph
b) of this subparagraph below. The amount of the bonds shall be set
by the Planning Board. If the Subdivider disagrees with the amounts,
he/she shall have the opportunity to submit a detailed estimate along
with supporting justification for the proposed revisions. The Board
may set the guarantee in a reasonable amount in excess of the estimated
costs in order to anticipate for increases in economic or construction
conditions. However, the amount of such increase shall not exceed
120 percent of the estimated cost of improvements.
b)
Time period. All performance guarantees shall
contain starting and ending dates. No Performance Guarantee shall
automatically expire before construction is completed. All construction
covered by a Performance Guarantee under Subparagraph c) below shall
be completed within twenty-four (24) months after the Planning Board
endorses the Final Plat.
c)
Required form. The security shall be in the
form of a financial instrument acceptable to the Finance Director
and approved by the Town Solicitor, and shall enable the Town to gain
immediate access to the secured funds within the period stipulated
in the guarantee, for cause. Performance covenants shall run with
the land, such that the ownership if all or a portion of subject land
is transferred, the new owner shall be subject to the provisions of
the performance covenant. Performance and maintenance guarantees may
be provided by one (1) of the following:
(1)
Security bond. The subdivider may obtain an
irrevocable security bond from a surety bonding company authorized
to do business in the State of Rhode Island.
(2)
Letter of credit. The subdivider may provide
an irrevocable letter of credit from a bank or other financial institution.
(3)
Escrow account. The subdivider may deposit
cash, or other instruments readily convertible into cash at face value,
either with the Town or in escrow with a bank.
d)
Recording of performance covenant and sale of lots. Before endorsement of its approval of the Final Plan, the Planning
Board shall require a Performance Covenant from the applicant which
shall ensure construction of ways and the installation of municipal
services in accordance with the applicable Subdivision Regulations
and conditions set by the Board. The Performance Covenant and endorsed
Final Subdivision Plan shall be recorded with the Town Clerk. Lots
shall not be released to allow sale or building unless performance
is secured by any of the three (3) methods described above, which
method or combination of methods may be selected and varied by the
Board, and required improvements have been installed as stipulated
herein.
e)
Releases. Release of security shall be conditioned
on the satisfactory completion of construction and installation of
required improvements to the land within two (2) years of the date
of final approval. At the expiration of the final plan approval period,
if all required improvements are complete and satisfactory as-built
drawings have been received, any improvement guarantee shall be returned
to the subdivider, subject to the recommendation of the Planning Board
and approval by the Town Council. Partial releases or reductions in
the guarantee amount may also be authorized prior to the expiration
of final approval. A written request for release or reduction of any
improvement guarantees shall be made to the Administrative Officer.
After satisfactory inspection of all required improvements, the Director
of Public Works shall recommend in writing to the Planning Board,
which may then recommend to the Town Council (a) to authorize the
Finance Director to return all improvement guarantees to the subdivider,
(b) that the amount of the guarantee being held by the Town be reduced
to cover the estimated cost of remaining improvements; or (c) that
no releases or reductions be made. No reduction in the amount of the
security at any one time shall be greater than fifty percent (50%)
of the total amount of the initial improvement guarantee, nor shall
the cumulative reductions reduce the security to less than fifty percent
(50%) of the initial improvement guarantee prior to final release
of the guarantee. The Planning Board may, in its sole discretion allow
a reduction in the amount of the initial improvement guarantee one
(1) time only prior to the provision of the security instrument by
the developer.
[Amended 4-29-1998[2]]
[2]
Note: Last sentence changed 4-29-1998 from 'No reduction
in the amount of the security at any one time shall be greater than
fifty percent (50%) of the total amount of the security.'
f)
As-built drawings. Within thirty (30) working
days of completion of construction of all required improvements, and
before the performance guarantee is released and the maintenance bond
is accepted, the developer shall furnish two (2) sets of transparent
mylar as-built drawings of required improvements to the Administrative
Officer. Additionally, a complete set of As-Built Drawings showing
all changes made to the original construction plans shall be provided
to the Administrative Officer. The As-Built Drawings shall be marked
"As-Built Drawing" and shall be certified by a registered professional
civil engineer or a registered land surveyor.
g)
Phased subdivisions. In the case of land development
projects or subdivisions which are approved and constructed in phases,
the Planning Board shall specify improvement guarantees related to
each particular phase. If any off-site improvements or other improvements
or conditions which are not directly related to a particular phase
are required as a condition of approval, the Board shall, in setting
the guarantee amount for each phase, clearly specify when such guarantees
are to be provided.
h)
Acceptance of improvements.
(1)
Upon completion of all required improvements, the subdivider shall convey all public improvements to the Town for ownership and maintenance. Private facilities, such as open space and privately maintained drainage systems shall not be conveyed to the Town. The applicant shall first request the Department of Public Works to conduct a final inspection as provided in Article X Section N. The Director of Public Works shall certify to the Administrative Officer in writing that all required improvements have been satisfactorily completed.
(2)
The applicant shall also request, in writing to the Administrative
Officer, that public improvements, streets, land, easements or other
facilities be accepted by the Town. This request shall contain a description
of all facilities to be accepted and shall be accompanied by an accurate
legal description of all streets, easements, land or other facilities
by metes and bounds and by reference to the final plat drawing(s)
and by a warranty deed transferring ownership to the Town and describing
any special conditions or other requirements.
(3)
Upon certification of completion of all required improvements, and
upon receipt of all required information from the applicant, the Administrative
Officer shall place the request for acceptance on the next available
agenda of the Planning Board. If all requirements of these Regulations
have been met by the applicant, the Planning Board shall recommend
acceptance by the Town Council of all such improvements to be dedicated
to the Town, and shall transmit such recommendation to the Town Council
in writing. In such recommendation for acceptance by the Town Council,
the Planning Board shall also recommend an amount for a maintenance
bond in accordance with these Regulations and shall recommend to the
Town Council that no public improvements or facilities be accepted
for ownership and maintenance until such maintenance bond has been
submitted as required in Subparagraph 4 of this Section.
(4)
Upon their acceptance by the Town Council, all improvements to be
dedicated to the Town shall be permanently owned and maintained by
the Town as part of the municipal system and the subdivider shall
be no longer responsible for their care, repair, or maintenance.
4.
Maintenance guarantees. Prior to acceptance of the improvements
for maintenance by the Town and release of the security, the applicant
shall be required to file with the Finance Director a maintenance
bond equal to five percent (5%) of the total surety amount, guaranteeing
the proper functioning and durability of all improvements for a period
of one (1) year after the date of their acceptance by the Town. At
the end of the one (1)-year maintenance period, the Director of Public
Works shall inspect all improvements subject to the guarantee and
shall certify in writing to the Administrative Officer as to their
condition. If found to be unacceptable, the Administrative Officer
shall recommend an extension of the guarantee period to the Finance
Director, and the original funds shall not be returned to the subdivider.
If public improvements are in good condition and have not been damaged
due to the fault of the subdivider, or through faulty workmanship
or design, the maintenance guarantee shall be returned to the subdivider.
a)
In cases where the Planning Board finds there are extenuating circumstances,
the initial maintenance period may be established for a period longer
than one (1) year. The reasons for establishing a longer maintenance
period and the nature of the extenuating circumstances shall be made
a part of the record.
5.
Extension of time. If, due to circumstances beyond the
control of the applicant, the construction of required improvements
to the land cannot be completed within the prescribed time, the Planning
Board may grant a time extension for legitimate reason, for a period
of time determined by the Planning Board to be appropriate to ensure
satisfactory completion of all improvements. During such time extension,
all guarantees shall remain in full force and written performance
guarantees shall be extended for same amount of time. Such requests
for an extension of time shall be made in writing to the Planning
Board at least ninety (90) days prior to expiration of the original
security.
6.
Default.
a)
Condition of default. The Town of Portsmouth
shall hold the applicant and surety in default of guarantee should
any one (1) or more of the following conditions occur:
(1)
Failure to comply with all specifications for construction, inspections,
and/or required improvements to the land.
(2)
Failure to properly notify the Director of Public Works on the beginning
and completion of all phases of construction of required improvements
to the land.
(3)
Failure to protect existing improvements and/or properly repair such
improvements should any damage occur during the construction within
the subdivision.
(4)
Failure to remove all debris from the site and adjacent areas immediately
and upon completion of construction with the subdivision and/or as
directed by the Director of Public Works.
(5)
Failure to complete the required improvements to the land within
the time prescribed by these Rules and Regulations.
b)
Certificate of default. Should any of the
conditions cited in Subparagraph 6.a) above occur, the Director of
Public Works shall certify in writing to the Planning Board that the
subdivider has not complied with the requirements of the Subdivision
Rules and Regulations. The Director of Public Works shall further
certify the extent of non-compliance and the conditions thereof.
c)
Execution of guarantee. The Planning Board
shall under the provisions of Title 45, Chapter 23, Section 45-23-46,
of the General Laws of Rhode Island, 1992, as amended, execute only
that portion of the guarantee which shall be necessary to correct
the deficiency for which the subdivider and surety are held in default.
d)
Payment by surety. Upon notification to the
surety by the Planning Board that the subdivider has been held in
default of guarantee, the surety shall promptly pay to the Town of
Portsmouth that portion of the guarantee which shall be necessary
to correct the deficiency for which the subdivider and surety are
held in default.
The applicant shall be required to provide to the Town insurance sufficient to indemnify the Town of Portsmouth against any claims for damage to property or personal injury, including coverage for all persons authorized in Article V. Section E. to inspect the improvements on behalf of the Town, which may occur on the property being subdivided as a result of any construction activity required as a condition of subdivision approval. Such insurance shall be submitted to the Administrative Officer for review prior to endorsement of the plat by the Planning Board, and shall remain in full force and effect during the construction period.
[Amended 4-29-1998[1]]
Two percent (2%) of the total estimated cost of all required
public improvements as estimated in accordance with the procedure
established in Section O. shall be paid to the Town for deposit in
an account to be used to pay for inspection services. Inspection fees
shall be paid in full before final approval by the Planning Board
or recording of the plat, or phase thereof, or in any case prior to
any construction, for which there will be public improvements requiring
inspection. The Planning Board may require the developer to pay additional
inspection fees based on actual costs should the two-percent (2%)
fee be insufficient. Inspection, verification and preparation of reports
by the developer's engineer shall not be compensable out of the
two-percent (2%) inspection fee.
[1]
Note: Last sentence added 4-29-1998.
Other fees shall be paid in accordance with a separate fee schedule
adopted by the Portsmouth Town Council.
