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Sec. 23-101. - Definitions.#
Unless specifically defined within this Article, specific terms and phrases are defined within Article II, Definitions.
(Reg. No. 2026-1, 1-6-26)
Sec. 23-102. - General development design.#
The purpose of good development 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 town. To promote this purpose, land development projects, subdivisions, and development plan review projects shall conform to the standards contained in this section, which are designed to result in a well-planned community without adding unnecessarily to development costs.
I.
Site analysis.
a.
Site analysis. An analysis of the development site and nearby areas, containing the information specified in attachment 3 of these regulations, 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 preapplication meeting and shall be presented by the developer during the first stage of review. Such an analysis may be required by the planning board for minor developments and 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.
Contents of site analysis. Such a site analysis shall include written and/or graphic analysis of the following characteristics of the development site: soils; agricultural lands; wetlands; coastal features; topography; ecology; existing vegetation, structures and road networks; visual features; past and present use of the site; historical and archaeological burial sites; and a preliminary assessment describing the potential effects of the proposed project on the natural resources of the site.
II.
General standards.
a.
Buildings, site improvements, and parking areas should be designed to preserve and minimize changes to existing topography and the loss of mature vegetation. Areas of environmental sensitivity should be avoided. Development should take advantage of natural features to reduce the need for regrading, cuts, and fills while ensuring an efficient site layout. Where feasible, existing topography and landscape features should be integrated to enhance site design and support stormwater management, balancing functionality with minimal disturbance to the natural landscape. To the maximum extent practicable development shall be located [to] minimize negative impacts and alteration of natural features, existing topography, mature vegetation, historic and cultural resources, historical and archaeological burial sites, and areas of scenic value which contribute to the character of the town
b.
Where possible, the developer should consider the following specific areas for undeveloped open space or lot areas in the design of the development:
(1)
Unique and/or fragile environmental areas;
(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)
Agricultural lands;
(4)
Historically significant structures and sites, as listed on federal or state lists of historic places;
(5)
Historical and archaeological burial sites, as defined in G.L. ch. 23-18 and chapter 50, section 50-8 of the Tiverton Town Code;
(6)
Habitats of endangered wildlife, as identified on applicable federal and/or state lists;
(7)
Lands within the 100-year flood zone, or wave velocity zone; and
(8)
Steep slopes in excess of twenty-one percent (21%) as measured over a ten-foot interval unless appropriate engineering measures concerning slope stability, erosion and resident safety are taken.
c.
The development shall be laid out to avoid adversely affecting groundwater and aquifer recharge; to reduce cut and fill; to avoid unnecessary impervious cover; to prevent flooding; to provide adequate access to lots and sites; and to mitigate adverse effects of traffic, drainage and utilities on neighboring properties. In addition, no ground disturbance or excavation shall occur within twenty-five (25) feet of the outer boundary of a known historical and archaeological burial site.
d.
Wetlands and significant natural features should be preserved in their undisturbed form, ensuring that flooding potential is not increased and stormwater entry and discharge points are designed to minimize erosion. Water quality features such as bioswales, retention, and detention basins should be integrated into the overall site design, leveraging existing topography and natural features while maintaining a strong emphasis on aesthetics and visual impact.
e.
Design of the development shall take into consideration all existing town and regional plans for the surrounding communities.
f.
Applicability of general standards. General design standards are delineated above to ensure that developers consider certain qualitative values in the design of their developments. The goal of stating such standards is to have developers take reasonable measures to preserve the environment, the natural resources and the scenic beauty of the town, so that Tiverton remains a desirable place to live and work. Because some standards as stated are subjective, however, common sense must prevail in their application. The obligation of the developer is to consider the standards and use them to the degree practical in the design of the development. The obligation of the planning board is to be reasonable in judging whether there has been sufficient consideration of the standards. If it is determined by the planning board that insufficient consideration has been given to the standards, the burden shall be on the planning board to provide objective evidence to support their finding. Applications subject to Conservation Development shall comply with the additional standards provided in Article XVII.
III.
Development density.
a.
Constraints to development. When calculating the maximum number of allowed lots or units on any parcel, constraints to development as defined in these regulations, shall be deducted from the total acreage of the parcel, and from the minimum area of each lot required under zoning. Such land may be included in any lot in a development, provided, however, that such land shall not be counted toward the minimum lot size. See Article V Section 3 of the zoning ordinance.
b.
Yield plan. When a rural residential development, Conservation Development, comprehensive permit development, or any other non-conventional development is proposed, the number of developable units or lots shall be the number of lots which would be permitted under a conventional application determined by the submittal of a yield plan, as defined in these regulations, and accepted and approved by the Planning Board.
c.
Yield plan standards. Yield plans shall be prepared at each phase of the development and shall conform to the following:
(1)
Yield plans shall show all areas with constraints to development, proposed streets and drainage facilities, easements and rights-of-way, and house lots designed according to the dimensional standards required by the zoning ordinance and specifically Article V of the Tiverton Zoning Ordinance, and including minimum lot areas free of land with constraints to development.
(2)
All streets and all house lots shall meet the general design standards contained in this Article, including minimum contiguous areas of land suitable for development, as defined in these regulations.
(3)
The location of the well and on-site wastewater disposal system shall be shown on each lot.
(4)
The yield plan must be drawn to scale and be a realistic layout reflecting a development pattern that could reasonably be expected to be implemented, taking into account all site characteristics, including soil suitability for on-site wastewater disposal, and all applicable state regulations and local development standards. In addition to meeting all dimensional requirements, the yield plan shall not assume that any waivers or other relief from the zoning and subdivision regulations will be granted, including waivers or variances from RIDEM with respect to OWTS requirements. The applicant shall have the burden of proof with regard to the reasonableness and feasibility of the design and of the engineering specifications for such yield plan, provided, however, that the Planning Board's determination of the basic maximum number of viable lots shall be conclusive.
d.
Land unsuitable for development. Unsuitable land is defined in article II of the Tiverton zoning ordinance and is to be excluded when calculating the allowable density of a subdivision or other land development project. Land deemed unhealthful for residential purposes in the judgment of the planning board, following consultation with the Rhode Island department of health and/or the department of environmental management, will not be approved for subdivision. For the purposes of these regulations, unsuitable land shall also include land upon which building is prohibited or impractical, such as utility easements, historical sites, historical and archaeological burial sites, habitats of species of state concern, and stormwater drainage components (detention/retention ponds, swales).
IV.
General site design standards.
a.
Site, circulation, parking and landscaping standards:
1.
Visual screening of refuse areas, service and storage yards and exterior work areas shall be accomplished by use of walls, appropriate fencing, plantings or a combination of these.
2.
Mechanical equipment and utility hardware on the roof or ground adjacent to the building shall be screened from public view with materials harmonious to the building, or with landscaping.
3.
All permanent utility lines shall be located below grade.
4.
The design and size of exterior lighting, when used, shall be compatible with the building and the adjacent areas, and shall not adversely affect neighboring residential properties.
5.
The layout and design of all means of vehicular and pedestrian circulation, including interior drives, parking areas and walkways, shall provide for safe interior circulation and separation of pedestrian, vehicular and service traffic.
6.
All sites shall provide safe means of vehicular ingress and egress from a public road with access drives and parking areas designed to ensure that vehicles are not required to back out onto public roads.
7.
The number of site entrances should be the minimum necessary for effective traffic control, and sharing of access driveways and parking areas by adjoining properties should be considered where possible. Where practical, sites should provide internal circulation links to adjoining sites.
8.
The parking area shall be adequately surfaced and maintained. Parking spaces required in connection with the dwelling uses need not be permanently surfaced.
9.
Provisions for pedestrian movement, in the form of sidewalks or walkways, shall allow for safe access between parking areas and retail establishments.
10.
Lighting requirements: Lighting fixtures used to illuminate the parking area shall be of the proper type to minimize light spill and placed so as to prevent unwanted light trespass onto adjoining properties.
b.
Building location and design standards:
1.
Primary building entrances shall be prominently located, easily identifiable, and relate to human scale. Buildings shall be designed and oriented with an emphasis on the primary street on which they front.
2.
Buildings located on corner lots shall incorporate design elements that are respectful of their orientation.
3.
Facades should blend with other buildings in the surrounding area, with compatible facade proportions, fenestration and general architectural style, or otherwise be compatible with the historic character of the town. Building sides without windows are discouraged and if done, corrected with architectural details.
4.
Architectural elements which create variety, interest and texture are encouraged. Elements which are out of portion to the overall building, such as exaggerated dormers, should be avoided.
5.
Buildings should have the same materials, or those that are architecturally harmonious, used for all walls and other exterior building components.
6.
Additions or alterations to existing buildings should be complementary in scale to the original structure, and architectural details, including materials, colors and textures shall be treated so as to be compatible with the original architectural style of the building, provided that such details preserve and enhance the character of the surrounding area.
V.
Landscape design and tree preservation.
a.
Reasonable landscaping shall be provided at site entrances, in public areas, in parking lots and adjacent to buildings. The type and amount of landscaping required shall be allowed to vary with the type of development.
b.
The plant, tree species, 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, shall be diverse in height, form and color, and shall be disease-resistant. The use of grass that require minimal watering and fertilization is encouraged, particularly in areas that are ecologically sensitive.
c.
Vegetated buffer areas may be required where necessary to avoid adverse impacts from adjacent uses.
d.
Existing stone walls should be preserved and incorporated into the site and landscape plan where practical. Development should prioritize the least naturally sensitive or significant portions of the site to protect natural features such as stone walls, significant trees, ponds, and streams. If a stone wall must be relocated or disturbed due to traffic flow or public safety concerns, the planning board may require its restoration, relocation, or rebuilding, ensuring connections with adjacent stone walls to the greatest extent possible.
e.
Landscape/tree preservation plan. The planning board shall require that a landscape plan be submitted to the board when it determines that existing landscaping is insufficient; where the site of the proposed development has been disturbed so as to require significant new vegetation; or where additional landscaping is necessary to protect, preserve or enhance significant visual characteristics of the site. If a landscape/tree preservation plan is required by the board, the applicant shall be advised of this requirement at the preliminary plan stage of a minor land development or subdivision, and at the master plan stage of a major land development or subdivision. Such plans shall include location of all landscaped areas with the proposed trees, shrubs, or other plant or ground covering material with information on the size, type and spacing. If said plan is required, it shall be stamped by a registered Rhode Island landscape architect.
f.
Maintenance agreement. A landscaping maintenance agreement may be required that provides for maintenance of plantings, utilizing acceptable horticultural practices and for replanting of new material where required plants have not survived.
VI.
Commercial and industrial development design.
Any applicant undergoing land development review or development plan review of any proposed non-residential development shall submit the information required in the checklist for the appropriate stage of review. Commercial and industrial developments shall be designed according to the same principles governing the design of residential developments: buildings shall be located according to topography, with environmentally sensitive areas avoided to the maximum extent practicable; factors such as drainage, noise, odor, lighting and surrounding land uses considered in siting buildings; sufficient and safe access shall be provided; and adverse impacts buffered. In addition, the planning board shall apply the standards for site and landscaping requirements for off-street parking contained in section 1, article X, special provisions of the town zoning ordinance in reviewing proposed new, expanded or redeveloped commercial and industrial uses.
(Reg. No. 2026-1, 1-6-26)
Sec. 23-103. - Control of stormwater runoff.#
Stormwater runoff is responsible for transporting eroded sediments, nutrients, petroleum hydrocarbons, heavy metals, pesticides, road salts, pathogens and other pollutants to receiving waters. To reduce the impact of these pollutants and to control the flooding impact of stormwater runoff, the requirements of this section for drainage system design shall be met. Drainage systems shall be constructed in accordance with the specifications contained in the appendix.
I.
General standards.
a.
Impervious surfaces and site disturbance should be reduced to the greatest extent possible, and as much natural undisturbed vegetation as possible shall be retained.
b.
Natural drainage patterns shall be maintained whenever possible.
c.
The developer is encouraged to incorporate natural elements into the drainage design whenever possible. These elements (grass swales, wet basins) collect and transport stormwater, but also mitigate pollution, reduce sedimentation and provide visual amenities and potential wildlife habitat.
d.
Storm drains, culverts, catch basins and related facilities shall be designed to ensure adequate drainage at all low points along streets, to prevent additional water from flowing onto adjacent properties and to intercept stormwater runoff along streets at intervals reasonably related to the extent and grade of the area being drained.
e.
A proposed drainage system shall be designed to accommodate stormwater such that post-construction conditions do not result in peak runoff increases in rate or volume from pre-construction conditions.
f.
Lots/assigned areas/parcels shall be prepared and graded consistent with drainage within the development and in such a manner that development of the lots shall not cause detrimental drainage on another lot, adjacent parcels or areas outside the development.
g.
Where any part of a drainage system is proposed for location outside the public street right-of-way, provisions shall be made for future maintenance and approved by the planning board.
h.
All necessary easements to off-street watercourses shall be obtained by the developer.
i.
Adequate physical access for maintenance purposes shall be provided in and around all drainage facilities. When determined to be necessary by the planning board, a detention pond shall be provided with a suitable means of protection around its perimeter, such as fencing or vegetation.
II.
Stormwater management plans.
a.
A stormwater management plan must be submitted for all proposed land development projects and subdivisions as required by the appropriate submittal requirements. The principal emphasis of stormwater management shall be the reduction of land disturbance and impervious surfaces, the preservation of vegetated buffers, and the use of proven techniques to control peak discharge rates, reduce runoff volumes and improve water quality.
b.
The design of a stormwater management plan and drainage system shall be undertaken by a professional engineer. The stormwater drainage calculations, runoff rates and system design shall be based on the application of the appropriate method as follows:
(1)
Rational method. This method is the preferred method for small systems of one acre or less, where no wetlands, ponds or other storage depressions are present and where drainage is towards the point of analysis. It is also the preferred technique for pavement drainage calculations needed to size drainage components in highway, industrial and commercial applications.
(2)
TR-55. This is the preferred method for calculating runoff volumes, peak discharge rates and flood storage requirements for site developments between one acre and 2,000 acres.
(3)
TR-20. This method is used for large complex watersheds, multiple watershed projects and systems beyond the scope of the TR-55 method.
(4)
Other methods. Other methods may be accepted by the planning board, provided the applicant submits all necessary information for the review process.
c.
A stormwater management plan shall be based upon the Rhode Island Stormwater Design and Installation Standards Manual (except as modified by these regulations) and must contain the following:
(1)
A description of best management practices (BMPs) for the proposed development. These BMPs must be illustrated on detailed site plans and described within the written plan. Structural BMPs shall be designed as amenities for the development which add open space, recreation, wildlife habitat and screening between different land uses, while also providing peak discharge rate control and pollutant reduction.
(2)
A maintenance schedule for each BMP.
(3)
A written narrative that describes the proposed measures to reduce peak discharge rates, maintain sheet flow (where possible) and improve water quality. This narrative must demonstrate that all flood control and water quality performance will be met.
(4)
An assessment of the structural integrity of the proposed stormwater system to withstand discharge from a two- to 100-year storm.
d.
Where deemed appropriate, the planning board may require land disturbance envelopes for each lot as part of the stormwater management plan.
III.
Stormwater performance standards and requirements.
a.
Section 2 of the State of Rhode Island Stormwater Design and Installation Standards Manual is incorporated by reference into these performance standards.
b.
A continuous drainage system will be installed and connected to a natural or manmade watercourse or to an existing piped storm drainage system. The ultimate destination of such continuous drainage is a permanent natural body of water or wetland. Where the planning board determines that such ultimate destination is impractical, the board shall require the construction of a retention area capable of accommodating proposed stormwater volumes based on a 100-year frequency rainfall.
c.
The discharge from any stormwater facility must be conveyed through properly constructed watercourses to provide for nonerosive flows during all storm events. The proposed stormwater conveyance system, consisting of open channels, catch basins, pipes, etc., shall, at a minimum, accommodate runoff from a 25-year frequency storm.
d.
Proposed projects must control and maintain post-development peak discharge rates from the two-, ten- and 25-year storm events at predevelopment levels.
e.
When deemed necessary by the planning board, downstream analysis of the 100-year storm event shall be required. Where warranted, control of the peak discharge rate for the 100-year storm shall be required to mitigate downstream impacts.
f.
Where detention, retention and infiltration systems are required, their design shall provide that, under a 50-year frequency storm, peak runoff and stream flows at the boundaries of the development will be no higher following development than prior to development.
g.
At a minimum, eighty percent (80%) of total suspended solids (TSS), as calculated on an average annual basis, must be removed from the development's stormwater. A volume calculated by multiplying one (1) inch by the impervious surface area contained within the contributing drainage area, and incorporated into a properly designed, installed and maintained BMP will result in the above reduction in TSS. Additional volumes must be incorporated into the BMP to store expected sediment loads. The additional sediment volume must be consistent with the individual BMP maintenance schedule.
h.
Wet ponds must have a permanent pool volume equal to the water quality volume described in [subsection] III.g above.
i.
Extended detention dry ponds must detain the water quality volume over a 36-hour period (brim drawdown time).
j.
Infiltration methods must be designed to retain and exfiltrate the water quality volume over a maximum 72-hour period.
k.
Where site conditions restrict the construction of BMPs that will meet these design criteria, the applicant must explain within the stormwater plan narrative how the eighty percent (80%) TSS removal rate will be obtained.
(Reg. No. 2026-1, 1-6-26)
Sec. 23-104. - Viewshed protection.#
Preliminary and final plans must evaluate the impact of the proposed development on scenic viewsheds. To the extent practicable, and consistent with the intended function of the proposed development, any impairment of viewshed quality must be avoided or minimized. New developments should maintain existing viewsheds by avoiding the destruction of existing wooded/vegetative buffers along arterial and limited-access streets. In addition, visual buffers between new structures and such streets shall be provided. Visual buffers between residential and commercial/industrial areas shall be provided as well.
(Reg. No. 2026-1, 1-6-26)
Sec. 23-105. - Soil erosion and sediment control.#
Soil erosion and sediment control plan. A plan to control erosion and sedimentation during construction, consistent with the requirements of the current town soil erosion and sediment control ordinance, chapter 65 of the Town Code, shall be submitted.
(Reg. No. 2026-1, 1-6-26)