Town of Westerly, RI Article VI Design and Improvement Standards

§ A261-29 General physical design and improvement requirements.

A. All physical design requirements for subdivisions and land development projects to be reviewed and approved pursuant to these regulations are contained in this section of these regulations and in the Town of Westerly Manual of Public Improvement Standards (maintained by the Town Engineer; copies available in the Town Clerk's office). The Westerly Manual of Public Improvement Standards shall be considered part of these regulations by reference.

[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

B. These regulations specify all necessary findings, formulas for calculations and procedures for meeting said requirements and policies. These requirements and policies shall apply to all developments and land development projects reviewed and/or administered under these regulations.

C. The slope of land shall not be excluded from the calculation of the buildable lot area or the minimum lot size, or in the calculation of the number of buildable lots or units.

[Added at time of adoption of Code (see Ch. 1, General Provisions, Art. I)[1]]

[1] Editor's Note: The addition of Subsections C and D renumbered Subsections C through G as Subsections E through H, respectively.

D. Wetland buffers, as defined in RIGL 2-1-20, shall be included in the calculation of a minimum lot area and in the total number of square feet or acres of a tract or parcel of land before calculating the maximum potential number of units or lots for development; provided, however, that this shall not apply to lots directly abutting surface reservoirs with direct withdrawals used for public drinking water. Nothing herein changes the definition and applicability of a "buildable lot" as set forth under RIGL 45-23-60(a)(4); and nothing herein permits the disturbance of wetlands or wetland buffers or otherwise alters the provisions of the Freshwater Wetlands Act, RIGL 2-1-18 et seq.

[Added at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

E. The requirements and policies include, but are not limited to, those concerning rights-of-way, open space, landscaping, connections of proposed streets and drainage systems with those of the surrounding neighborhood, and the relationship of proposed developments to natural and man-made features of the surrounding neighborhood.

F. Public improvement standards are, in some cases, specific for certain areas or districts of the Town. Standards include, but are not limited to, specifications for rights-of-way, streets, sidewalks, lighting, landscaping, public access, utilities, drainage systems, fire protection, and soil erosion control.

G. All public improvements of a land development project or development shall reflect the physical character and design for that district which is specified by the Westerly Comprehensive Plan.

H. Lists of all application requirements for administrative subdivision, preapplication and concept review, minor land development and minor subdivision and major land development and major subdivision, are contained in Article XI.

I. The land development or subdivision developer, at his own expense, shall construct all improvements required by the Planning Board as shown on the approved final plans of the development

§ A261-30 Specific physical design and improvement requirements.

[Amended 9-20-2011]

A. This section contains the specific design standards which shall apply to all land development and subdivisions to be constructed in the Town of Westerly.

B. Street design standards. The following design standards shall be followed where applicable in the design and construction of any land development or subdivision:

(1) Frontage on improved streets.

(a) The area to be developed shall have frontage on an existing street; if the street does not meet the standards and specifications as required in these regulations, the Board may require the applicant to make certain improvements along the part of the street abutting the property or leading to the property being developed where necessary for drainage, safety, traffic or other reasons as deemed proper by the Board. See Subsection H of this § A261-30.

(b) For purposes of these regulations, streets platted but not improved and accepted for maintenance by the Town shall not be considered existing improved public streets. Where these streets are incorporated within the development, they shall be improved by the developer to meet the Land Development and Subdivision Regulation standards.

(2) Street classification. Street design within a proposed development shall conform to a street hierarchy system as established herein. Requirements for right-of-way and pavement width, on-street parking, drainage and other utilities, sidewalks, bicycle path and other design standards shall be tailored to street function.

(a) Street classification shall be determined by the Planning Board. The following references are used in making the determinations:

[1] Technical Paper Number 130, Highway Functional Classification System, for the State of Rhode Island, latest edition. Division of Planning, Rhode Island Department of Administration, One Capitol Hill, Providence, RI 02903.

[2] A Policy on Geometric Design of Highways and Streets, latest edition. American Association of State Highway and Transportation Officials.

[3] Recommended Guidelines for Subdivision Streets. Institute of Transportation Engineers, Washington, DC: ITE, latest edition.

[4] Trip Generation. Latest edition. Washington, DC: Institute of Transportation Engineers.

[5] Local Low Volume Roads and Streets (LLVRS), latest edition, USDOT, FHWA.

(b) The following major categories of street classification are established:

[1] Arterial: a major public street that serves as an avenue for the circulation of traffic into, out of, or around the Town and carries high volumes of traffic and provides for high levels of mobility.

[2] Collector: a public street whose principal function is to carry traffic between local streets and arterial streets but that may also provide direct access to abutting properties. These streets provide a balance between land access and mobility.

[3] Local public: public streets whose primary function is to carry traffic between local streets and arterial streets but that may also provide direct access to abutting properties. These streets provide a balance between land access and mobility.

[4] Local private: private streets whose primary function is to provide access to abutting properties. Streets within residential cluster or planned unit developments serving up to 20 residential dwellings and streets in minor residential subdivisions serving up to five residential dwellings on a private street also fall within this classification.

(3) Street rights-of-way. Street rights-of-way shall conform to the widths shown on Table 1 below as illustrated in the reference column. Drawings 1, 2 and 3[1] (See Article XI.) illustrate typical cross sections of local streets. Specific design criteria will be determined by the Board on a case-by-case basis. Drawing 1 is a typical cross section of a local street proposed for acceptance and maintenance by the Town. Where the developer proposes the use of grass swales in lieu of a continuous piped stormwater drainage system, any of the alternative cross sections shown in Figure 2 may be used, subject to the approval of the Planning Board. Refer to Subsection D, Drainage, of this § A261-30 for more specific design criteria.

Table 1
Street Type	Right-of-Way (feet)	Cross Section Design Reference
Arterial (Town accepted)	75	See AASHTO Green Book
Collector (Town accepted)	60	See AASHTO Green Book
Local (Town accepted)	50 50	Drawing 1 Drawing 2 (Board approval required)
Private streets (See Ch. 260, Zoning, § 260-46, Cluster development, and § 260-48, Planned Development Zoning District.)	50	As per Board requirements

[1] Editor's Note: The drawings are on file in the Clerk's office.

(4) Geometric data. Table 2 below shall be used as a guide in designing streets within a proposed development.

Table 2 Minimum Standards for Town Roads Geometric Construction
Feature		Local Streets (Public)	Cluster Development or PUD
Right-of-way width		50 feet	50 feet
Pavement width, including berms		30 feet	18 feet to 22 feet (minimum)
Maximum grades:
	At center line (CL)	6%	6%
	Within 150 feet of intersecting CL	2.5%	2.5%
Minimum grades at CL		1%	0.5%
Minimum length for vertical curves		100 feet1	As per DPW
Minimum radius of curves at CL and a minimum of 100 feet tangent between curves		150 feet	100 feet
Minimum sight distance		200 feet	100 feet
Cul-de-sac (turnaround):
	Diameter of right-of-way	120 feet	100 feet
	Diameter of pavement2	98 feet	80 feet
	Maximum grade	4.5%	4.5%
	Minimum grade	2%	2%
Intersection fillet curve:
	Minimum radius right-of-way	15 feet	15 feet
	Minimum radius pavement	25 feet	25 feet
Pavement crown		5 inches	3 inches

NOTES:
1	Less than 30 feet for each one-percent algebraic in grade.
2	Where approved by the Planning Board, culs-de-sac may be designed with a circle with a forty-foot unpaved center. The Planning Board will determine landscape requirements for the unpaved center.

(5) Street layout and arrangement.

(a) The arrangement of each street 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. See also § A261-30G(6)(a).

(b) 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 principal means of egress. In order to provide for alternative access, at least two vehicular access streets may be required by the Planning Board, in major subdivisions when determined by the Board to be feasible. Proposed streets within subdivisions shall provide for the 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.

(6) Private streets. Private streets may be permitted by the Planning Board in appropriate circumstances such as residential cluster and planned unit developments authorized by Chapter 260, Zoning, of the Code of the Town of Westerly. It shall be the responsibility of the developer to provide street name(s) to the Engineering Department for emergency purposes. Written confirmation of approval shall be provided to the Planning office prior to final approval. Said streets or private ways shall not bisect lots.

(7) Street intersections. Street intersections shall either coincide precisely with or be offset by at least 200 feet from other intersections. Intersections shall be at ninety-degree angles. Lesser angles between 75° and 90° may be approved by the Town Engineer.

(8) Dead-end streets (cul-de-sac). All dead-end streets shall end in a cul-de-sac turnaround constructed according to the table of geometric data above and shall be clearly marked at their entrances. The Planning Board may limit the length of the dead-end street (cul-de-sac) where necessary, to ensure the adequate and safe circulation of vehicular traffic.

(9) Street names. Street names shall conform to the requirements of Chapter 94 of the Town Code.

[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

(10) Access to adjoining property.

(a) When considered desirable by the Planning Board to provide access to adjoining property, proposed streets shall be continued and improved to the property line. The reservation of strips of land preventing such access shall not be permitted. The Planning Board may require provision of a temporary turnaround until such time as the adjacent tract is developed. 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.

(b) 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.

(c) In all commercial applications internal vehicular connectivity shall be created and maintained between contiguous commercial parcels.

(11) Street signs. Street name and traffic signs will be as per the Manual of Uniform Traffic Control Devices for Streets and Highways (USDOT-FHA) and approved by the Town Engineer. Installation and provision of street signs and 911 designation on public streets shall be the responsibility of the Westerly Engineering Department; for private streets these duties shall be the responsibility of the developer.

[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

(12) Street trees. Where natural tree growth is determined by the Planning Board to be insufficient, the Planning Board shall require the developer to plant street trees appropriate for the terrain, soil and climatic conditions encountered in the development, and in accordance with the following standards. Other trees may be selected and used on a per-site basis with the approval of the Town Planner.

(a) Location. Street trees shall be located on the portion of building lots within 20 feet of the street right-of-way line, if assurance can be given by the developer that the trees will not be disturbed by building activities. In either case, no street trees shall be located so as to interfere with overhead or underground utility lines. Trees shall be spaced approximately 30 feet to 50 feet on center, depending on anticipated ultimate size.

(b) Type. The species selected are to be suitable for Zone 6 hardiness and may include, but not be limited to, the following types (use of invasive species shall be prohibited):

[1] Deciduous medium to large trees suitable for use where there are underground utilities such as:

Acer rubrum	Red maple
Betula nigra	River birch
Carpinus betulus	European hornbeam
Cercidiphyllum japonicum	Katsura tree
Cladrastis kentukea	Kentucky coffee tree
Fraxinus pensylvanica	Green ash
Ginkgo biloba	Ginkgo
Gleditsia triacanthos 'Inermis'	Thornless honey locust
Gymnocladus dioicus	Kentucky coffeetree
Liquidambar styraciflua	American sweetgum
Platanus x acerifolia	London planetree
Platanus occidentalis	American planetree
Prunus sargentii	Sargent cherry
Quercus bicolor	Swamp white oak
Quercus palustris	Pin oak
Quercus rubra	Northern red oak
Sophora japonica	Japanese pagoda tree
Tilia cordata	Little leaf linden
Ulmus parvifolia cultivars	Lacebark elm

[2] Small deciduous trees suitable for use under power lines with fifteen-foot ultimate height such as:

Acer palmatum species	Japanese maple
Amelanchier Canadensis	Shadblow serviceberry
Carpinus caroliniana	American hornbeam
Hydrangea paniculata	Panicle hydrangea
Koelreuteria paniculata	Goldenraintree
Prunus sargentii	Sargent Cherry
Syringa reticulata	Japanese tree lilac

[3] Conifers such as cedar, Cryptomeria, Chamacyparis, pine, hemlock, spruce may be used only within the ten-foot area allowed on the lots or as a vegetative buffer to adjacent land uses not part of the subdivision.

(c) Size. Minimum sizes for species listed above are 1 1/2 inches to two inches caliper, measured one foot from ground level in place, and six feet to eight feet of height in place.

(d) Quality. Street trees shall be balled and burlapped with good root development and branching characteristics. Street trees proposed adjacent to a sidewalk shall have lower branches at six feet above sidewalk grade. Bare root handling for dormant trees up to 2 1/2 inches caliper may only be allowed during the spring season. All trees shall be licensed nursery stock; however, native trees may be used if inspected and approved by the Town Tree Warden before planting. Trees shall be from a local source so as not to spread insect or pathogen infestations from other geographic regions.

(e) Planting. Street trees shall be planted so the top of the root ball is level with the existing grade and the bottom of the pit being undisturbed subgrade to prevent settling of the tree and 1 1/2 times as wide as the root ball. Larger excavation may be required in gravel or sand areas. Trees shall be planted at their previous depth in good-quality topsoil or soil conditioned to the quality with sufficient organic matter such as peat moss and a balanced fertilizer. Trees shall be securely double-staked with sturdy stakes of a minimum size of two inches by two inches by six feet. Staking and or guying shall be removed after one year.

(f) Screening. Where a proposed residential development abuts an existing or proposed commercial or industrial area, a dense evergreen buffer at least 10 feet in depth and eight feet tall shall be planted along the common boundary between the residential development and such commercial or industrial development. Fences shall not be a substitute for this requirement.

(g) Inspection. The Town Tree Warden shall determine the suitability of the street trees being proposed and certify proper planting techniques and maintenance have been followed.

(13) Landscaping standards.

(a) Landscaping shall be provided as part of site plan design. It 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.

(b) Landscaping shall include plant materials such as trees, shrubs, ground covers, grass, flowers, etc., and shall also include, but is not necessarily limited to, the following features:

[1] Drainage facilities, such as retention/detention basins, drainage swales, rain gardens and bioretention areas (§ A261-30.1).

[2] Entrance features.

[3] Open space areas.

[4] Proposed recreation facilities.

[5] Buffer areas.

[6] Lot areas which are disturbed during the construction process or where extensive grading removes a significant amount of natural vegetation.

[7] Areas subject to regrading or stabilization for soil erosion and sediment control purposes.

(c) Landscape plan. A landscape plan prepared by a registered landscape architect or equivalent shall be submitted to the Planning Board as part of a major land development or subdivision when:

[1] Existing landscaping is insufficient.

[2] The site of the proposed development has been disturbed so as to require significant new vegetation.

[3] Additional landscaping is necessary to protect, preserve, or enhance significant visual characteristics of the site. When a requirement for additional landscaping is required by the Board, the applicant shall be advised of this requirement at the preliminary review stage of an administrative or minor land development or subdivision and at the master plan stage of a major land development or subdivision. The plan shall identify existing and proposed trees, shrubs and ground covers; natural features such as stone walls and rock outcroppings; man-made elements such as retaining walls (see § 260-87.3), fences (see § 260-68), signs (see 260-86), planters, etc.; proposed grading at two-foot contour intervals; lighting (following dark sky lighting principles found at www.nature.nps.gov); specifications for loaming (six inches standard), fertilizing and seeding; and other proposed landscaping, and shall include construction details as necessary. Industrial and commercial development projects shall have frontage planting and shall incorporate parking lot landscaping standards where necessary § 260-77. A planting schedule shall be included to indicate proposed planting by genus species and cultivar, 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.

(14) Monuments. Monuments (concrete or granite boundary markers) shall be of the type approved by the Town and paid for by the developer and placed by a registered land surveyor on the street line at the beginning and end of all right-of-way horizontal curves PC's and PT's on both sides of each development (public) street and shall not be more than 500 feet apart. Monuments shall be set four inches above the finished grade of the center of the street.

(15) Sidewalks.

(a) Sidewalks shall be required to be installed on one side of all proposed new public streets in developments located in Residential HDR-6 and HDR-15 and Business HC, GC, NB, P-15, GI, SCG, SCWH Zoning Districts and in all residential cluster developments or multifamily developments except for short cul-de-sac streets serving five or fewer lots or dwellings. Sidewalks may be required to be installed along new streets in other areas if the Planning Board finds any of the following:

[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

[1] The development is located within an area within one mile of a public or private school; or

[2] The development is located in reasonable proximity to major public or private facilities such as churches, shopping areas, playgrounds, etc., where there is a reasonable likelihood that pedestrian traffic to/from/within the proposed development would result; or

[3] The development is located within an area with high vehicular traffic volumes and where there would be a likelihood of significant danger to pedestrians.

(b) Sidewalks may be required to be installed as off-site improvements in accordance with the provisions of § A261-30H.

(16) Bicycle paths. Bicycle paths shall be incorporated into the proposed development where necessary to extend an existing bicycle path; to intersect with proposed state bicycle facilities; to connect adjacent development where vehicular connections would be impractical; or where adjacent or nearby public or private school recreation areas or other similar facilities would be likely to generate significant bicycle traffic.

(17) Curbing at intersection fillet curves. Slope-faced precast concrete curbing meeting RIDOT Standard 7.21 shall be installed at all intersection fillet curves in lieu of extruded Cape Cod curbing. Precast concrete wheelchair ramp curbs meeting RIDOT Standard 7.19 shall be installed where required by the Town Engineer.

(18) Engineering and land survey. Wherever it is mandated by these regulations that certain tasks associated with development plans and improvements be performed by registered professional engineers and/or registered land surveyors, all such tasks shall be performed according to existing and amended standards of the State of Rhode Island Board of Registration for Professional Engineers and Board of Registration for Land Surveyors.

(19) Traffic study. Traffic studies, where required by the Planning Board, shall be prepared and presented by a registered professional engineer with traffic expertise.

C. Lot design standards.

(1) Side lot lines. Side lot lines shall be at right angles to street line 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.

(2) Developable land area. All lots shall be designed so as to contain the minimum land area required by Chapter 260, Zoning, of the Code of the Town of Westerly. The lot design shall be such that there will be no foreseeable difficulties, due to site conditions, in securing building permits on all lots and in providing necessary access and frontage to such lots from an existing or proposed street. See § A261-15, Land unsuitable for development.

(3) Easements. 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.

(a) Watercourses. Where a development is traversed by a watercourse, drainageway, channel or stream, there shall be provided a stormwater easement or drainage right-of-way conforming substantially with the lines of such watercourse and of such width as will be adequate for the purpose.

(b) Sanitary sewers. Easements across lots or centered on rear or side lot lines shall be provided for sanitary sewers where they are required. The Planning Board may require permanent easements of such width as recommended by the DPW, plus temporary construction easements if necessary. The minimum nominal width for a sewer easement shall be 30 feet.

(c) 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 20 feet. Where aboveground 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.

(d) 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 development approval.

(e) 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 such as a structure, tree, shrub, wall, earthen embankment, hill or any other obstruction.

(f) Bicycle or pedestrian access easements. Bicycle and pedestrian access shall be provided where required on a separate strip of land dedicated to the Town or on an easement having a minimum width of 15 feet.

(g) Other easements. All other required easements shall be of sufficient width and area for the intended purpose. All utility easements shall be a minimum width of 20 feet and contain at least one concrete bound.

(4) Lot configurations. The Planning Board shall have the right to prohibit or require modification to lots that are shaped or configured in such a manner as to conflict with the use of the land for the intended purpose. The Board may, in reviewing a proposed development, require modification to the proposed lot layout as it deems necessary to achieve the purposes of these regulations. The following guidelines shall be considered for lot layout and design:

(a) Long narrow strips of land and unusual or irregular shapes, angles and dimensions for a lot are discouraged.

(b) Other than at corners, lots shall abut only one existing or proposed street.

(c) Corner lot street lines shall have sufficient width to accommodate required front building setback lines on both abutting streets.

D. Drainage. This section shall comply with the RIDEM Rhode Island Stormwater Design and Installation Standards Manual promulgated December 2010 and any subsequent revisions thereto.

(1) The drainage system may be comprised of natural and man-made elements. These include grass swales, bioretention areas, rain gardens (§ A261-30.1), retention and detention basins, curbs, catch basins (shall have four-foot sumps), culverts, and stormwater pipes. The developer is encouraged to incorporate natural elements into the drainage design whenever possible. These elements (i.e., grass swales, wet basins) not only collect and transport stormwater but also mitigate pollution, reduce sedimentation, provide visual amenities and provide potential wildlife habitat. Wet basins shall be mechanically animated from dawn to dusk to prevent the hatching of mosquitoes.

(2) Where a drainage plan and drainage calculations are required by the appropriate application requirements in Article XI, the plan and calculations shall be prepared by a registered professional engineer. The stormwater drainage calculations, runoff rates and system design shall be based on the application of the appropriate method as follows:

(a) The Rational Method. This method is the preferred method for small systems of three acres or less, where no wetlands, ponds, or other storage depressions are present, and where drainage is toward the point of analysis. All maps and data used for the design of the proposed drainage system shall be submitted to the Town Engineer.

(b) TR-55. This is the preferred method for calculating runoff volumes, peak discharge rate, and flood storage requirements for site development between one acre and 200 acres. All maps and data used for the design of the proposed drainage system shall be submitted to the Town Engineer.

(c) TR-20. This is for large complex watersheds and systems beyond the scope of the TR-55 or where other watershed tributaries may be affected by the proposed development. All maps and data used for the design of the proposed drainage system shall be submitted to the Town Engineer.

(d) The drainage plan and drainage calculations shall contain the following information:

[1] An estimate of the quantity of stormwater surface runoff presently flowing from the land proposed to be developed, and that which would be generated by the proposed development, calculated on the basis of a fifty-year-frequency rainfall.

[2] An estimate of the quantity of stormwater surface runoff entering the development naturally from upstream areas within the watershed under present conditions, calculated on the basis of a fifty-year-frequency rainfall.

(3) An analysis of the capability of existing watercourses, storm sewers, culverts and other drainage facilities within the land proposed to be developed to handle the runoff as calculated under Subsection D(2)(d)[1] and [2] above, and proposals to handle such surface runoff. Design criteria for drainage improvements shall conform to the state specifications cited above or as modified by the Town of Westerly. Culvert and storm pipes shall be reinforced concrete pipe (RCP), designed for a fifty-year (Type III) frequency rainfall, with a minimum pipe size of 15 inches, and a minimum flow velocity of four feet per second (fps). Private roads shall be built to Town standards and approved by the Town Engineer. The maximum flow velocity shall not exceed 15 fps, and under no circumstances shall the velocity head at the pipe outlet exceed the vertical elevation difference between the crown on the pipe outlet and the bottom of catch basin frame.

(4) Proposals for disposal of surface runoff, downstream from the development, without damage to land and improvements and to the receiving water body are prohibited.

(5) The drainage plan shall further indicate how the following specific requirements be met:

(a) That each lot will be adequately drained; with roof drains connected to dry wells or rain gardens; surface water from driveways greater than 4% in slope shall have trench drains to divert runoff into grass swales, dry wells, water-quality trenches or rain gardens (§ A261-30.1);

(b) That natural drainage patterns will be maintained;

(c) That all existing watercourses will be left open;

(d) That all new open watercourses will be seeded, sodded or paved depending on grades and soil types;

(e) That a closed drainage system will be installed and maintained on site. The ultimate destination of any drainage shall not be a permanent natural body of water or wetland. The Board shall require the construction of multiple retention basins, wet ponds, or bioretention areas capable of accommodating proposed stormwater volumes based on a one-hundred-year-frequency rainfall;

(f) Where any part of the drainage system is proposed for location outside the public street right-or-way, provisions for future maintenance approved by the Planning Board shall be provided;

(g) That all necessary easements to off-street watercourses shall be obtained by the developer; and

(h) Where volume or velocity of the surface is high, the flow thereof shall be controlled by riprap, sediment basins, flow spreaders, or other applicable devices and/or techniques recommended in the Rhode Island Soil Erosion and Sediment Control Handbook.

(6) The proposed drainage system shall be designed to accommodate stormwater such that post-construction conditions result in zero net runoff in rate or volume from pre-construction conditions.

E. Utilities.

(1) Sanitary sewers. Sanitary sewers shall be required in all developments and land development projects where such sewer service is required in accordance with the procedures and standards set forth in Chapter 206, Sewers, and Chapter 251, Water, of the Town of Westerly Code.

(2) Municipal water. Municipal water shall be required in all developments and land development projects where such water service is required in accordance with the procedures and standards set forth in Chapter 251, Water, of the Town of Westerly Code. Water curb stops shall be provided for each lot in accordance with the rules and regulations of the appropriate water utility company. Waterlines shall be generally located on the southerly or westerly side of the street wherever possible or as required by the Planning Board.

(3) Gaslines. Natural gaslines may be installed in any development or land development project at the discretion of the developer. The developer must present to the Planning Board correspondence from the gas company to the effect that the utility company does not intend to provide gas to the site within the next five years. If proposed, gaslines shall be located on the northerly or easterly side of the street wherever possible or as required by the Planning Board.

(4) Communication lines (electric, telephone, and cable TV).

(a) All electric, communications (telephone, fire alarm and cable TV) and streetlighting lines shall be installed underground. In cases where underground installation is not feasible due to physical conditions of the site or other limitation, an alternative location for these utility lines shall be approved by the Planning Board, if prior approval thereof has been obtained by the utility company involved. The use of conventional streetlighting shall be kept to a minimum in residential subdivisions; however, renewable source lighting, i.e., solar, shall be preferred and dark sky lighting principles incorporated in the fixtures.

(b) Communications lines are not required to be placed underground for minor subdivisions where no street creation is required, or for minor subdivisions where a private street is required, and the Town will not be requested to accept the street for ownership and maintenance, but shall be built to Town standards.

(5) Fire hydrants. Fire hydrants shall be installed in all developments where public water supply systems are installed. Hydrant type, location, and spacing shall meet the minimum requirements of the National Fire Protection Association, or as directed by the appropriate fire district.

F. Erosion and sediment control. (See § 260-89.) All major land developments and major subdivisions shall submit a soil erosion and sediment control plan as required herein.

(1) Minor land developments, minor subdivisions and administrative subdivisions shall not be required to submit such plans if the land-disturbing activity involved in construction of subdivision improvements meets all of the following criteria:

(a) Construction activity will not take place within 200 feet of any wetland or coastal feature;

(b) Slopes at the site of land disturbance do not exceed 7%;

(c) The total area of such activity does not exceed 10,000 square feet;

(d) Proposed grading does not exceed two feet of cut or fill at any point;

(e) The grading does not involve a quantity of fill greater than 60 cubic yards, except where fill is excavated from another portion of the development parcel and the quantity of fill does not exceed 185 cubic yards;

(f) All disturbed surface areas are promptly and effectively protected to prevent soil erosion and sedimentation.

(2) Plan preparation. The erosion and sediment control plan shall be prepared by a registered engineer, a registered landscape architect, a soil and water conservation society certified erosion and sediment control specialist, or a certified professional soil scientist.

(3) Plan contents. The erosion and sediment control plan shall include sufficient information about the proposed activities and land parcel(s) to form a clear basis for discussion and review and to assure compliance with all applicable requirements of these regulations. The plan shall be consistent with the data collection, data analysis, and plan preparation guidelines in the current Rhode Island Soil Erosion and Sediment Control Handbook, prepared by the United States Department of Agriculture, Natural Resources Conservation Service, Rhode Island Department of Environmental Management, Rhode Island Conservation Committee, and, at a minimum, shall contain:

[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]

(a) A narrative describing the proposed land-disturbing activity and the soil erosion and sediment control measures and stormwater management measures to be installed to control erosion that could result from the proposed activity. Supporting documentation, such as a drainage area, existing site conditions, and soil maps, shall be provided as required by the Planning Board.

(b) Construction drawings illustrating in detail all land-disturbing activity, including existing and proposed contours, cuts and fills, drainage features, and vegetation; limits of clearing and grading; the location of soil erosion and sediment control and stormwater management measures; detail drawings of control measures; stockpiles and borrow area; sequence and staging of land-disturbing activities; and other information needed for construction.

(c) Other information or construction plans and details as deemed necessary by the Planning Board for thorough review of the plan prior to action being taken as prescribed in these regulations.

(4) Performance principles. The contents of the erosion and sediment control plan shall clearly demonstrate how the principles, outlined below, have been met in the design and are to be accomplished by the proposed development project.

(a) The site selected shall show due regard for natural drainage characteristics and topography.

(b) To the extent possible, steep slopes shall be avoided.

(c) The grade of slopes created shall be minimized.

(d) Post-development runoff rates shall be zero net runoff. Any increase in storm runoff shall be retained and recharged as close as feasible to its place of origin by means of retention ponds, wet ponds or basins, seepage areas, subsurface drains, porous paving, or similar bioretention techniques.

(e) Original boundaries, alignment, and slope of watercourses within the project locus shall be preserved.

(f) In general, drainage shall be directed away from structure intended for human occupancy, municipal or utility use, or similar structures.

(g) All drainage provisions shall be of such a design and capacity so as to adequately handle stormwater runoff, including runoff from tributary upstream areas which may be outside the locus of the project.

(h) Drainage facilities shall be installed as early as feasible prior to any additional site clearance or disturbance.

(i) Fill located adjacent to watercourses shall be suitably protected from erosion by means of riprap, gabions, retaining walls, vegetative stabilization, or similar measures.

(j) Temporary vegetation and/or mulch shall be used to protect bare areas and stockpiles from erosion during construction; the smallest areas feasible shall be exposed at any one time; disturbed areas shall be protected during the nongrowing months, November through March.

(k) Permanent vegetation shall be placed immediately following fine grading.

(l) Trees and other existing vegetation shall be fenced or roped off to protect trees from construction equipment.

(m) All areas damaged during construction shall be reseeded or otherwise restored. Monitoring and maintenance schedules, where required, shall be predetermined. See Chapter 224, Stormwater Management, of the Westerly Code of Ordinances.

(5) Maintenance of measures. Maintenance of all erosion-sediment control devices under this chapter shall be the responsibility of the developer. The erosion-sediment control devices shall be maintained in good condition and working order on a continuing basis. Watercourses originating and located completely on private property shall be the responsibility of the developer to their point of open discharge at the property line or at a communal watercourse within the property. If proper maintenance procedures are not followed, the Planning Board may authorize the Town Engineer to take the steps necessary to ensure proper maintenance by using improvement guarantee funds as provided in § A261-19B.

(6) Periodic inspections. The Town Engineer may require inspections at such intervals as deemed necessary to assure proper compliance with the approved erosion and sediment control plan. Copies of all inspection reports shall be submitted to the Administrative Officer and will be made available to the developer upon request.

G. Site design.

(1) Purpose. The purpose of good 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.

(2) Site analysis.

(a) An analysis of the development site and nearby areas shall be required by the Planning Board for all major land developments and subdivisions. The scope and content of the site analysis shall be discussed during the pre-application meeting and shall be presented by the developer 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.

(b) 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; watercourses, wetlands; coastal features; topography; climate; ecology; existing vegetation, structures, and road networks; visual features; and past and present use of the site.

(3) Subdivision and site design.

(a) Design of the development shall take into consideration all existing Town and regional plans for the surrounding community.

(b) Development of the site shall be based on the characteristics of the site and upon the site analysis. 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.

(c) 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 including associated buffers and coastal features including associated buffers and floodplains;

[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;

[3] Lands in a floodplain;

[4] Steep slopes in excess of 15% as specified in § A261-15, Land unsuitable for development, as measured over a ten-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;

[6] Historically significant structures and sites, including cemeteries (§ 260-71) as listed on federal or state lists of historic places; and

[7] Agricultural lands.

(d) The development shall be laid out to avoid adversely affecting recharge; to reduce cut and fill; to avoid necessary 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.

(4) Residential development design.

(a) The Planning Board may vary street locations, lot shapes (see § A261-30C(4) et seq.) and dimensions, and setbacks for the purpose of encouraging and promoting flexibility, economy, and environmental soundness in layout and design, provided that the lot areas and dimensions and setbacks within the development conform to the minimum requirements of Chapter 260, Zoning, and provided that such standards shall be appropriate to the type of development permitted.

(b) Residential lots shall front on local streets.

(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) The placement of dwelling units in residential developments shall take into consideration topography, privacy, building height, orientation, drainage, and scenic values.

(e) Lots shall be designed so that proposed buildings have adequate privacy from adjacent streets.

(f) Vegetated evergreen buffer areas eight feet in height shall be required where necessary to avoid adverse impacts from adjacent uses. Fences shall not be a substitute for this requirement.

(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; factors such as drainage, noise, odor, and surrounding land uses considered in the proposed location of buildings; sufficient access shall be provided; and adverse impacts buffered.

(6) Circulation system design.

(a) 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 pattern; to respect natural features and topography; and to present an attractive streetscape.

(b) In residential subdivision, the road system shall be designed to serve the needs of the neighborhood and to discourage use by through traffic.

(c) The pedestrian system shall be located as required for safety. In conventional developments, walks shall be placed parallel to the street, as shown in the typical street cross sections in § A261-30,[2] with exceptions permitted to preserve natural features or to provide visual interest. In residential cluster developments and land development projects, walks may be placed away from the road system with permission of the Planning Board. Where commercial uses are contiguous, internal interconnected circulation for vehicles and pedestrians shall be incorporated into the design to reduce the number of curb cuts onto a major roadway.

[2] Editor's Note: Drawings of typical street cross sections are on file in the Clerk's office.

(7) Landscape design.

(a) Reasonable landscaping should be provided at site entrances, in public areas, and adjacent to buildings. The type and amount of landscaping required shall be allowed to vary with type of development. Use of invasive plants is prohibited.

(b) 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.

H. Off-site improvements.

(1) Purpose. This section is intended to ensure that developers provide off-site infrastructure improvements in order to mitigate the impacts which are directly or indirectly attributable to new development. Such improvements may be required by the Planning Board if the Board finds that there is a reasonable relationship between the requested improvement and the proposed new development. Off-site improvements may include but are not limited to improvements to the following: sanitary sewers, water supply systems, roadways, sidewalks, bicycle paths, and drainage systems.

(2) Definition and principles. As a condition of final approval, the Planning Board may require a developer to construct reasonable and necessary improvements located off of the proposed land being developed. "Necessary improvements" are those clearly and substantially related to the subdivision or land development being proposed. The Planning Board shall provide in its resolution of final approval the basis for requiring such off-site improvements. In its resolution, the Board must find that a significant negative impact on existing conditions will result if the off-site improvements are not made, and are clearly documented in the public record. The mitigation required as a condition of approval must be related to the significance of the identified impact. All required off-site improvements must reflect the character defined for that neighborhood or district by the Westerly Comprehensive Plan.

I. General construction procedures. The following procedures shall be followed by the developer and by contractors under the direction of the developer in the construction of any land development or subdivision or related improvement.

(1) Pre-construction meeting. A pre-construction meeting shall be held with the Town Engineer at least seven days prior to the start of any subdivision improvements. The developer (or his duly authorized representative) and the on-site project manager shall attend this meeting.

(2) Notification. No step in the construction of required improvements shall commence until the Town Engineer has been notified at least 48 hours in advance of the phases of construction listed in Subsection I(3) below.

(3) Inspection of improvements.

(a) Inspection and approval by the Town Engineer shall be required for the following phases of construction improvements:

[1] During and following installation of all underground drainage structures, systems and utilities prior to backfilling. No underground components shall be backfilled until approval from the DPW and/or Town Engineer is secured;

[2] During and following the preparations of the road subgrade and shoulders;

[3] During and following the spreading and compaction of the subbase course;

[4] During and following the spreading and compaction of the base course prior to the application of the asphalt binder course;

[5] Immediately prior to and during the application and compaction of the asphalt surface course on the roadway and, if required, sidewalks;

[6] Following completion of all improvements and installation of bounds; and

[7] At periodic intervals as required to ensure compliance with the approved erosion and sediment control plan.

(b) The Town Engineer may require inspection at such other intervals as may be deemed necessary to assure proper construction of improvements. Approval for each or all of the above stages does not constitute acceptance by the Town.

(4) Request for inspection. Whenever an inspection is required, the developer shall request the Town Engineer to make such inspection. The Town Engineer or his representative shall, within 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.

(5) As-built drawings. Upon completion of construction of all required improvements, and before the performance bond is released and the maintenance bond is accepted, the developer shall furnish two sets of transparent Mylar as-built drawings of required improvements to the Administrative Officer.

(6) Inspection fees. Inspection fees shall be paid in the amount established in § A261-12B and shall be paid in full before construction begins of any improvements requiring inspection.

§ A261-30.1 Bioretention and stormwater management.

A. Definitions. When used in § A261-30.1, the following words and phrases shall have the following meanings:

BIORETENTION

A method of treating stormwater by pooling water in a depression on the surface of the ground and allowing filtering and settling of suspended solids and sediment at the mulch layer, prior to entering the plant/soil/microbe complex media for infiltration and pollutant removal.

CISTERN

A tank for catching and storing rainwater. This water can be recycled and used for landscape and lawn irrigation.

RAIN OR RECHARGE GARDENS

Utilize bioretention techniques to accomplish water quality improvement and water quantity reduction.

GRASS SWALE

A grass depression that collects stormwater and settles sediment before it enters a larger drainage area.

B. Purpose. The purpose of bioretention practices is to improve stormwater problems and to enhance the principle of zero net runoff from all properties. These practices reduce the use of curb and gutter construction and encourage sheet flow to retention areas and grass swales, which reduce runoff volume that creates downstream flooding during major storm events. The practice also reduces runoff velocity by increasing the time of concentration that water remains in filter soil and planted areas, which can filter pollutants and recharge groundwater. The planted portions of these bioretention areas shall enhance aesthetics and provide habitat for native flora and fauna.

C. Application. Upon application for minor or major subdivision or land development project, the best practices of bioretention shall be applied. All new residential infill lots, all residential subdivisions on a per-site basis, all mixed residential and commercial areas on a per-structure basis, commercial parking lots, all industrial and hazardous uses, retrofit applications for existing lots, new highways and roads, and the retrofit of existing local roads shall be designed to meet all State of Rhode Island standards and must be approved by the Town Engineer prior to preliminary plan submission. Sizing of the bioretention areas shall be determined by the amount of impervious cover proposed for the individual sites. The Planning Board shall make a determination on a site-by-site basis as to the feasibility of bioretention practices. The Planning Board shall have the authority to modify the requirements herein to address site specific constraints and possible water contaminants.

§ A261-31 Construction methods and specifications.

A. Specifications.

(1) Construction of streets shall be in accordance with the Typical Cross Section of a street contained herein and the Standard Specifications for Road and Bridge Construction (1971 edition) published by the State of Rhode Island, Department of Public Works, Division of Roads and Bridges unless otherwise noted. Drinking water systems shall be constructed in accordance with the Town of Westerly, Department of Public Works, Water Main and Services Construction Specifications Manual. Wastewater sewer systems shall be constructed in accordance with the Town of Westerly, Department of Public Works, Manual of Standards and Specifications for the Construction of Sewer Collection Systems. Drainage systems shall be constructed in accordance with the Town of Westerly, Manual for Standard Specification for Miscellaneous Drainage Systems.

(2) The above technical manuals are adopted by reference to these regulations.

B. Soil erosion and sediment control. All soil erosion and sediment control measures required by these regulations shall be constructed in accordance with the standards and procedure set forth in the Rhode Island Soil Erosion and Sediment Control Handbook, prepared by the United States Department of Agriculture Soil Conservation Service, the Rhode Island Department of Environmental Management and the Rhode Island State Conservation Committee, 1989, and any amendments thereto. Said handbook is adopted by reference to these regulations.