Watershed Protection District

[Added 11-17-1997]

• 1. Purpose. The provisions herein governing the development and use of land in the Watershed Protection District, as defined in Subsection H.3. below, shall be minimum provisions, and shall be superimposed on the underlying zoning districts or parts of districts, and impose specified requirements in addition to, but not less than, those otherwise applicable for the underlying district, and shall consider any watershed protection management programs in neighboring areas. These provisions are established for the following purposes:
  • a) To protect, preserve and maintain the quality and quantity of drinking water supplies which are of substantial value as a public drinking water supply upon which the residents of the Town of Portsmouth and others depend by regulating the use and development of land adjoining water courses and/or primary water recharge areas;
  • b) To regulate or prevent uses of land within the Watershed Protection District having the potential to adversely affect the quality or quantity of the drinking water of the Town;
  • c) To locate all construction, land disturbance and drainage facilities at a maximum possible distance from drinking water reservoirs and their tributaries.
  • d) The Portsmouth Comprehensive Plan requires protective measures to ensure that our drinking water is plentiful and of the highest quality.
  • e) To protect the health, safety and general welfare of the public.

    It is intended that this section be interpreted in view of the paramount public interest involved in the protection of critical drinking water supplies.

• 2. Other regulations to apply. Except for the provisions of this section as they apply to the Watershed Protection District and in which such land is located, all other provisions of this Ordinance shall continue in full force and effect. Where there is a conflict between these provisions and those of the Portsmouth Land Development and Subdivision Regulations, these provisions shall prevail.

  Editor's Note: See Ch. 236, Land Development and Subdivision Regulations.

• 3. Designation of Watershed Protection District. The Watershed Protection District is that land area, the surface water and ground water from which have a direct or indirect effect on the quality of water in the primary water bodies of the watershed. The Watershed Protection District is defined as approximately that area bounded by Mill Lane on the north, thence proceeding south on Middle Road to its terminus on Union Street, thence proceeding east to East Main Road, thence proceeding south on East Main Road to the Middletown Town Line, thence proceeding west along the Town line to Jepson Lane, thence proceeding north along Jepson Lane to its terminus at Union Street, thence proceeding west on Union Street to its terminus at West Main Road, thence proceeding north to its intersection of Mill Lane.
  • a) Map III-1, which is derived from the "Water Quality Protection Plan for the City of Newport, December 1989", shall be used for determining inclusion in or exclusion from the Watershed Protection District, and shall supersede the written description above. The Zoning Officer shall determine from Map III-1 and on-site surface topography the location of a parcel or portion thereof in the Watershed Protection District.
  • b) Where the bounds of the Watershed Protection District are in doubt or in dispute, the burden of proof shall be upon the owners of the land in question to show where such bounds should properly be located. At the request of the landowner(s), the Town may engage a professional surveyor, hydrologist or soil scientist to determine more accurately the location and extent of the Watershed area and may charge the owner(s) for all or part of the cost of the investigation.
• 4. Designation of hydrological zones within the Watershed Protection District. The Watershed Protection District is composed of two subzones with differing permitted uses and other regulations, as approximated on Map III-2 herein. The reservoir/adjacent recharge zone "A" Zone, and an upland drainage area or "UD" Zone.
  • a) "A" Zone. The area close to the surface reservoir which is critical to the protection of surface and subsurface water supplies, and requires a high degree of protection from incompatible land uses.
    • (1) Within five hundred feet (500') from the edge of Lawton Valley Reservoir, St. Mary's Pond or Sisson Pond as determined by the methodology specified in the R.I. Freshwater Wetlands Act, and as certified by a professional engineer; and
    • (2) Areas of Stissing silt loam and Mansfield mucky silt loam (U.S. Soil Natural Resource Conservation Service "Se and Ma" soil types), as designated on the Soil Survey of Rhode Island 1981, as amended, the maps and definitions of which are hereby incorporated by reference to this Ordinance, as designated on the Watershed Protection District Map III-2, the locations of which may be confirmed by a soil scientist at the applicant's expense; and/or
    • (3) All streams, wetlands and their buffers that are determined by RIDEM application procedures to be tributaries to a drinking water reservoir, as defined in Subparagraph 4.c) below. Notwithstanding Subparagraph (2) above, wetland delineation, as defined by RIDEM regulations, shall be used to determine the exact bounds of the "A" zone within a parcel beyond the area designated in Subparagraph (1) above.
  • b) "UD" Zone. The watershed area designated which is contributory to surface water runoff to the primary water bodies either through surface water runoff or groundwater movement that is not in the "A" Zone.
  • c) The word "reservoir" shall be defined as Lawton Valley Reservoir, St. Mary's Pond, Sisson Pond, and Bailey's Brook.
  • d) Notwithstanding the provisions of Article III, Section D.1, where a lot is partially in the Watershed Protection District, that portion in the Watershed Protection District shall adhere to all requirements of this Section. Where a lot is partially in Zone "A" of the Watershed Protection District and partially in Zone "UD", the requirements of each zone shall be applied to that portion in the respective districts.
• 5. Permitted uses in Zone "A". The following are the only uses permitted in Zone A, regardless of uses allowed in the underlying zoning district. (There shall not be a listing of permitted uses in this district in the Use Tables in Article V.):
  • a) Conservation and management of soil, water, natural and wooded open areas and wildlife.
  • b) Public water lines and related facilities.
  • c) Public or private parks.
  • d) Single family houses and uses and improvements customarily accessory thereto.
  • e) Agriculture and outdoor recreation areas not including structures or impermeable surfaces, provided there are vegetated buffers around the primary impoundments that comprise the reservoirs.
  • f) Historic Monuments.
• 6. Prohibited uses in Zone "UD". Any use permitted in the underlying zoning district by right or by special exception is permitted as such, except for the following, which are expressly prohibited. (There shall not be a listing of permitted uses in this district in the Use Tables in Article V.)
  • a) Outdoor storage of junk or salvage materials.
  • b) Outdoor or underground storage of flammable, explosive or hazardous material as defined by RIDEM regulations, including petroleum, except as provided in Subparagraph 6.i) below.
  • c) Sewage treatment plant.
  • d) Incinerator.
  • e) Sanitary landfill.
  • f) Solid waste transfer station.
  • g) Vehicle washing establishment.
  • h) Uses which discharge wastewater other than surface water into other than an approved sewage disposal system.
  • i) Accessory uses to any principal use which involves any of the following practices:
    • (1) Storage or disposal of hazardous waste (including petroleum) as defined by Rules and Regulations for Hazardous Waste RIDEM 7/18/84, as amended;
    • (2) Placement of an ISDS within two hundred feet (200') of the surface water of a reservoir;
    • (3) Any underground storage of liquid fuel.
    • (4) Any above ground storage of liquid fuel in excess of three hundred (300) gallons for any residential use, except uses by public utilities subject to the provisions of RIDEM Oil Pollution Control Regulations. Above ground storage of liquid fuel in excess of three hundred (300) gallons for non-residential uses may be permitted provided that said storage is placed at a maximum feasible distance from the reservoirs and their tributaries, and that construction, containment and maintenance be in accordance with RIDEM Oil Pollution Control Regulations.
• 7. Prohibited uses in Watershed Protection District. The following uses are designated as a "Severe Threat to Water Quality" and are expressly prohibited from the Watershed Protection District:
  • a) Any use that would generate a wastewater discharge other than domestic sewage, including but not limited to:
    • (1) Photo processors.
    • (2) Furniture strippers.
    • (3) Laboratories.
    • (4) Dry cleaners.
    • (5) Laundromats.
  • b) Any use, storage or processing of a hazardous material, including but not limited to:
    • (1) Gas stations.
    • (2) Landfills.
    • (3) Oil distributors.
    • (4) Printers.
    • (5) Fertilizer, pesticide, or herbicide warehouse or storage, except storage conducted in accordance with the R.I. Pesticide Control Act, if applicable, or as permitted and regulated under the R.I. Pesticide Control Act or the R.I. Right to Farm Act.
    • (6) Auto body and auto repair shops.
  • c) A pre-existing nonconforming use or accessory use or a use previously permitted by Special Use Permit may be expanded by Special Use Permit if both the planned expansion and the prior use or accessory use meet the applicable State regulations on storage and use of hazardous materials, and both prior and planned storage of hazardous materials are not within three hundred feet (300') from the surface water of a reservoir or two hundred feet (200') from a tributary thereto, and an adequate enclosed containment system is provided.
• 8. Land use classification for uses not listed in Subsections 5, 6 or 7.

  Because this ordinance cannot anticipate every type of proposed use, other land uses within the Watershed Protection District are categorized by potential effects on water quality. For each of these proposed uses, the Zoning Board of Review shall determine the appropriate use classification. The Zoning Board of Review may require a set of mandatory protective measures (conditions) as part of any building or development permit according to the Use Classifications set forth below.

  The following categories, ranging from least to the most severe threat to water quality, apply:

  • a) Class 1 — No Risk

    Including but not limited to: Open space, passive recreation.

  • b) Class 2 — Slight Risk

    This category provides a substantial economic use to a landowner without posing a major risk to drinking supplies.

    Including but not limited to: Crops utilizing minimal amounts of fertilizers and pesticides including permanent pasture, hay crops and turf, low density residential [two (2) or more gross acres per dwelling unit], utility lines, and developed recreation.

  • c) Class 3 — Moderate Risk

    These uses require regulatory oversight and strict adherence to applicable mitigative measures to prevent contamination problems. Agricultural activities require application of an approved conservation plan and best management practices.

    Including but not limited to: Agricultural production including livestock, nurseries and orchards, corn, fruit and vegetables, medium density residential [one-quarter (1/4) to two (2) gross acres per dwelling unit], and commercial uses provided that total impervious surface is less than or equal to twenty-five percent (25%) of total lot area.

  • d) Class 4 — Higher Risk

    Threat of spills, leaks, or unauthorized discharge of domestic wastewater or hazardous materials from these land uses. Permitted with caution and with substantial mitigative measures.

    Including but not limited to: Institutional, high density residential [less than one-quarter (1/4) gross acre per dwelling unit], sand and gravel mining, appliance repair, commercial uses provided that no dimensional variance for total lot coverage per the provisions of Article VII., Section G. shall be permitted. Light industrial uses which do not require discharge of other than domestic wastewater, provided that no dimensional variance for lot coverage per the provisions of Article IV., Section B. shall be permitted. Uses which generate considerable wastewater and/or may utilize toxic or hazardous substances including, schools, hospitals, medical offices and nursing homes, motels/hotels, and car washes.

  • e) Class 5 — Severe Threat to Water Quality

    Uses which employ hazardous chemicals including but not limited to photo processors, furniture strippers, laboratories, printers, dry cleaners and laundromats, gas stations, oil distributors, auto body, underground fuel storage tanks, toxic chemical storage, except as provided under Subparagraphs 6.i) and 7.c) above, and commercial uses with impervious surface in excess of seventy percent (70%) of a lot are not permitted in the watershed protection area.

• 9. Mandatory development restrictions.
  • a) Stormwater drainage.

    For any subdivision adding or extending a street, discharge (including discharge via a stormwater basin) of stormwater into streams and wetlands that are determined by RIDEM application procedures to be tributaries to a drinking water reservoir, as defined in Subparagraph 4.c) herein, will not be permitted unless the applicant can provide adequate scientific and technical documentation and engineering plans which prove, to the satisfaction of the Town, that specific pollution controls and/or other mitigation measures and BMPs will completely eliminate any measurable impact to water quality. Said plans and documentation will become conditions of approval. The burden of proof rests on the applicant.

    • (1) Unless specified herein, all drainage facilities shall be designed and installed in accordance with Article X. of the Portsmouth Land Development and Subdivision Regulations.

      Editor's Note: See Ch. 236, Land Development and Subdivision Regulations.

    • (2) Calculations shall include estimated runoff from rooftops and driveways.
    • (3) A maintenance plan for each stormwater basin shall be filed.
    • (4) To the maximum extent practicable, stormwater shall be diverted to one (1) or more grass swales and other natural upland treatment facilities, rather than detention ponds located at the bottom of a hill. To the maximum extent practicable, stormwater shall be retained and allowed to infiltrate the soil on-site, rather than be discharged from the site.
    • (5) Storm water from the entire site shall be designed to remove eighty percent (80%) of total suspended solids. Storm water basins shall be designed in accordance with the RI Stormwater Design and Installation Standards Manual, and shall comply with Article X. of the Portsmouth Land Development and Subdivision Regulations.

      Editor's Note: See Ch. 236, Land Development and Subdivision Regulations.

    • (6) A maintenance guarantee, as provided in Article X. of the Portsmouth Land Development and Subdivision Regulations, shall be provided.

      Editor's Note: See Ch. 236, Land Development and Subdivision Regulations.

  • b) Septic systems regulations.
    • (1) Septic systems, including all leaching fields and other parts of a septic system, shall not be allowed within two hundred feet (200') of any water body or any stream or wetland that is determined by RIDEM application procedures to be tributary to a drinking water reservoir.
    • (2) A reserve area for replacement systems is mandatory in the watershed district. Said reserve area shall be subject to the same requirements as the main septic system. (Dual alternating leach fields, where the idle one is allowed to clean itself out over time, are encouraged.)
    • (3) Innovative/Alternative technology septic systems, as approved by RIDEM, which have been shown to greatly reduce nitrogen, pathogens, BOD and TSS, shall be used in all new construction within the "A" Zone. Such systems must have pressurized distribution to leach fields.
    • (4) All septic tanks installed after the effective date of this ordinance shall be certified watertight in accordance with ASTM standards, and guaranteed as such by the manufacturer.
    • (5) Galley systems are prohibited.
  • c) Sub-Drains on Lots: Installation of conduits such as tile, pipe, or tubing beneath the ground surface on a lot to divert ground water, to intercept or prevent water movement into a wet area, to relieve artesian 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 are prohibited if the individual and/or collective purpose is to obtain a septic system. Sub-drains are permitted in accordance with Article X. of the Portsmouth Land Development and Subdivision Regulations for other purposes, provided they are located at least twenty feet (20') from any portion of the septic system.
    • (1) Location and placement of developed areas. All development shall be situated as far from the reservoirs, tributaries, wetlands as reasonably possible. The Town shall consider soils and topography in making such decisions.
    • (2) At least fifty percent (50%) of each parcel within three hundred feet (300') of the surface water of a reservoir shall remain undisturbed.

    Editor's Note: See Ch. 236, Land Development and Subdivision Regulations.

• 10. Mandatory site design standards.

  Environmentally sensitive site design standards (best management practices) are required for all permitted uses, whether by special use permit or otherwise, in the Watershed Protection District. These standards are developed to optimize water quality, as opposed to technical "make do" compliance.

  The following measures shall be required, as applicable and feasible, in the best interests of protecting water quality:

  • a) Vegetated buffers must be maintained or planted around all critical environmental areas, including reservoirs, and their tributaries. Vegetated buffers ninety-five feet (95') in width shall be composed of the following:
    • (1) A strip of land fifteen feet (15') wide starting at the edge of the pond or stream bank, which shall be comprised of mature trees and shrubs that are to remain undisturbed. Outflow from subsurface drains must not be allowed to enter or pass through this area.
    • (2) Next to the fifteen foot (15') strip, a strip of land at least sixty feet (60') wide, which shall be comprised of trees and shrubs that may be managed as necessary. Outflow from subsurface drains must not be allowed to enter or pass through this area.
    • (3) Thence a strip of land at least twenty feet (20') wide, which shall be comprised of the devices designed to convert concentrated overland or piped flow to uniform shallow sheet flow.
    • (4) Specifications for these buffers shall be according to a publication entitled "Riparian Forest Buffers", U.S. Department of Agriculture. 1991. Trees and shrubs employed shall be selected based on a publication entitled "Sustainable Trees and Shrubs for Southern New England", University of Rhode Island, 1995.
  • b) Surface water runoff shall be directed toward areas covered with vegetation for surface infiltration.
  • c) Surface water runoff shall be directed toward the lesser restricted district where the property is located within two (2) or more districts, as feasible.
  • d) Parking lot controls, including pervious surfaces and drainage facilities shall be employed.
  • e) Buildings and impervious surfaces shall be set back at least one hundred fifty feet (150') from the inland edge of the reservoirs and their tributaries.
  • f) Minimize tree removal: Applicant must demonstrate why each area must be cleared. Priority shall be given to maintaining established trees. Existing natural buffers, as in 10.a) above, shall be maintained.
  • g) All grading, filling, excavation, tilling, or chemical use shall be set back at least one hundred feet (100') (or RIDEM regulations, whichever is greater, or per the R.I. Right to Farm Act if applicable) from the inland edge of the reservoirs and their tributaries.
  • h) Areas to be disturbed within three hundred feet (300') of any water body or wetland shall be clearly marked on approved plans. On site, prior to any construction activity, the areas to be disturbed shall be clearly delineated with stakes and ropes, or other appropriate material, and the downhill border of said area lined with staked hay bales in accordance with the Portsmouth Soil Erosion and Sedimentation Ordinance.

    Editor's Note: See Ch. 320, Soil Erosion and Sediment Control.

• 11. Design principles. The following design principles shall be employed for all developments in the Watershed Protection District:
  • a) Addressing Development Constraints with Respect to Site Features.
    • (1) Avoid slopes greater than fifteen percent (15%).
    • (2) Minimize impacts to groundwater.
    • (3) Recognize soil limitations.
    • (4) Avoid wetlands.
  • b) 'Sustainable Development' Principles.
    • (1) Design with topography and natural features.
    • (2) Creative preservation of open space.
    • (3) Compatibility with surrounding land uses.
  • c) Employing 'Mesi-scaping' Principles.
    • (1) Plant or preserve native vegetation to minimize need for irrigation and use of chemical additives.
  • d) Use of vegetative buffers.
    • (1) Create or restore vegetative buffers for non-point source pollution control and wildlife habitat.
    • (2) Link with existing buffer areas to protect stream and river corridors.
  • e) Orienting layout to minimize pollutant loading.
    • (1) Minimize roadways; locate roads to reduce de-icing requirements.
    • (2) Consider alternative ISDS/treatment systems, as approved by RIDEM.
• 12. Development plan review.
  • a) All proposed construction and development in the watershed, with the exception of individual single family houses and accessory uses, shall be referred to the Planning Board and shall undergo formal development plan review, per the above standards, and per the provisions of Article XI. Development Plan Review herein. Development of a single family house on a pre-existing lot shall be referred the Zoning Officer.
  • b) Environmental review assessment.
    • (1) A development requiring the construction of a street;
    • (2) A development requiring a storm water treatment pond; or
    • (3) A nonresidential development.
  • c) The Environmental Review Assessment shall contain appropriate supporting data on stormwater runoff and pollutant loading, setting forth the probable impact or effect of the proposed development on the water supply of the Town. In compiling such statement, the applicant shall consult with regional agencies having knowledge and authority in water quality protection, including but not limited to the Newport Water Department and the R.I. Dept. of Environmental Management, both of which shall receive notice of proposed development per the requirements of Article XIII Section C.2)b). The Environmental Review Assessment shall cover at least the subject areas listed herein for evaluation and conformance with pertinent local, state and federal performance standards.
  • d) The Environmental Review Assessment shall also contain a description of the existing environmental setting to include all manmade, natural and physiographic features within five hundred feet (500') of the property line including but not limited to wetlands or water bodies, topographic contours, vegetation and existing development.
  • e) Construction of one (1) single family house on a lot conforming to the minimum lot size and other provisions herein shall not be required to submit an Environmental Review Assessment.