Chapter 10-36 DESIGN STANDARDS

Chapter 10-36
DESIGN STANDARDS

Sections:

10-36-010 Basic Requirements

10-36-020 Conformance with Master Plan

10-36-030 Protection of Natural Features

10-36-040 Access Through Another Municipality

10-36-050 Streets

10-36-060 Sidewalks

10-36-070 Storm Sewers

10-36-080 Open Spaces

10-36-090 Electric and Telephone Lines

10-36-100 Sanitary Sewers

10-36-110 Streetlighting

10-36-120 Curb Cuts

10-36-130 Common Driveways

10-36-140 Subdivisions in Floodplains

10-36-150 Fire Hydrants

10-36-160 Water Mains and Appurtenances

10-36-170 Monuments

10-36-010 Basic Requirements

A. The subdivider shall observe all design standards for land subdivision as hereinafter provided. These standards shall be considered minimum standards and shall be varied from or waived only as provided in § 10-48-010.

B. Provision for extension. Reasonable provision shall be made for extension of pavements and utilities to adjoining properties, including installation of watergates and manholes if necessary. The subdivider shall not deny others connection to the utilities, provided that they pay all costs of such connection.

C. Design and construction.

(1) Design and construction shall reduce, to the extent possible, the following features:

(a) Volume of cut and fill. Cuts or fills in excess of eight (8) feet or roadway locations resulting in lots being more than eight (8) feet above or below the grade of the roadway shall be substantiated by the submission of cross sections showing the proposed grading within two hundred (200) feet of the roadway on both sides. [Amended 1-14-1991]

(b) Area over which existing vegetation will be disturbed, especially if within two hundred (200) feet of a river, wetland or water body or in areas having a slope of more than fifteen percent (15%).

(d) Extent of waterways altered or relocated.

(e) Dimensions of paved areas, including streets, except as necessary to safety and convenience, especially in aquifer recharge areas.

(2) Design shall emphasize, to the extent possible, the following:

(a) Use of collector streets to avoid traffic on streets providing house frontages.

(b) Visual prominence of natural features of the landscape.

(d) All streets in the subdivision shall be designed so that, in the opinion of the Board, they will provide safe vehicular travel. Due consideration shall also be given by the subdivider to the attractiveness of the street layout in concert with the topography and natural features of the land in order to obtain the maximum livability and amenity of the subdivision. Street patterns derived solely for the purpose of providing maximum lot development will be cause for disapproval. [Amended 1-14-1991]

D. Easements.

(1) Where utilities cross lots or are centered on rear or side lot lines, easements shall be provided for a width of at least twenty (20) feet.

(2) Where a subdivision is traversed by a watercourse, drainage way, channel or stream, the Board shall require a stormwater easement or drainage right-of-way of adequate width and proper side slope as determined by the Town Engineer or Planning Board agent to conform substantially to the lines of such watercourse, drainageway, channel or stream, and to provide for construction or other necessary purposes. In no case shall the width be less than twenty (20) feet or the side slope be steeper than two (2) horizontal to one (1) vertical.

(3) Access easements to parcels to adjacent property shall be provided, if required by the Board, for use by emergency vehicles and for the benefit of the town. They shall have a minimum width of twenty (20) feet.

(4) Wherever possible, easements along rear lot lines shall be continuous to the street at the end of the block to potentially connect with the adjoining blocks in the shortest direct line.

E. Utilities.

(1) All required utilities, exclusive of transformers, shall be placed underground at the time of initial construction. Required utilities may include water, sewer, storm drainage, telephone, electricity, gas, wiring for streetlights, fire alarm systems and cable television, unless otherwise specified by the Board.

(2) Where adjacent property is not subdivided or where all the property of the applicant is not being subdivided at the same time, provisions shall be made for the extension of the utility system by continuing the mains the full length of streets and to the exterior limits of the subdivision at such grade and size which will, in the opinion of the Board, permit their proper extension at a later date.

(3) Connections for sewer, drain, water, gas, oil, electric and telephone service from the main structure in the way to the exterior line of the way shall be constructed for each lot whether or not there is a building thereon, except that the Board may waive such requirement, in whole or in part, in the case of a lot to be used for a park, playground or for any other purpose for which, in the opinion of the Board, such connections shall not be required.

10-36-020 Conformance With Master Plan

Any proposed subdivision shall be guided by the proposals and intentions of the Northborough Master Plan and the recommendations of the Conservation Commission, although deviations may be made to improve the general area of the subdivision and the town. With each proposed subdivision, the applicant shall provide written documentation specifying how the proposed project conforms to the Master Plan. [Amended 2-11-1991]

10-36-030 Protection of Natural Features

All natural features, such as trees, wooded area, watercourses, wildlife habitat, scenic points and historic spots, shall be preserved as much as possible. Any clearance, backfilling, cutting, thinning or other disturbance to trees twelve (12) inches diameter at breast height located within the minimum front setback distance or other natural vegetation shall be prohibited unless deemed proper by the Board. Tree wells or retaining walls should be installed when and as requested by the Board for suitable grading around trees. Tree wells or retaining walls shall be of such design to meet the standards as set forth in the Tree Experts Manual or some similar publication. The contractor shall take all reasonable precautions and provide all reasonable protection to prevent damage to all trees not designated for removal, relocation or replacement in the course of construction. [Amended 2-11-1991; 5-6-2003]

10-36-040 Access Through Another Municipality

In case access to a subdivision crosses land in another municipality, the Board may require certification from appropriate authorities that such access is in accordance with the Master Plan and subdivision requirements of such municipality and that a legally adequate performance bond has been duly posted or that such access is adequately improved to handle prospective traffic.

10-36-050 Streets

A. Location and alignment.

(1) Streets shall be continuous, of uniform width and in alignment with existing streets, as far as practicable.

(2) Provision shall be made for the proper protection of streets, if adjoining property is not subdivided.

(3) All curved streets must be designed to permit safe vehicular travel. A minimum two-hundred-foot-length stopping sight distance shall be provided. A minimum two-hundred-twenty-five-foot center-line radius shall be provided on all streets. [Amended 2-11-1991]

(4) Street lines at intersections shall be cut back so as to provide curb radii of not less than thirty (30) feet.

(5) Streets shall be laid out so as to intersect as nearly as possible at right angles.

(6) Rights-of-way shall be located a minimum of fifteen (15) feet from abutting property lines. [Amended 10-7-1997]

B. Width.

(1) The width of rights-of-way shall be fifty (50) feet.

(2) The Board may require street rights-of-way, which, in its judgment, may become primary streets, to be sixty (60) feet in width.

(3) The minimum width of the actual traveled way in a subdivision shall be determined by the Board with regard to the nature of the subdivision, but shall not be less than twenty-six (26) feet in any case. [Amended 5-6-2003]

C. Grades.

(1) The center-line grade of streets shall not be less than seventy-five hundredths percent (0.75%), not more than six percent (6%) for primary streets and not more than ten percent (10%) for secondary streets. [Amended 5-6-2003]

(2) Vertical curves shall be installed wherever the change in grade exceeds two (2) percent. All vertical curves shall be designed to accommodate a minimum stopping sight distance of 200 feet, at a design speed of 30 mph. All calculations shall be based on the formulas listed in the Highway Design Manual produced by the Commonwealth of Massachusetts, Department of Public Works. [Amended 5-6-2003]

(3) Where the grade of any street at the approach to an intersection exceeds four percent (4%), a leveling area shall be provided having not greater than two-percent grades for a distance of fifty (50) feet measured from the nearest right-of-way line of the intersecting street, wherever possible a low point in the proposed roadway shall be created to prevent stormwater flow onto an existing town road. [Amended 5-6-2003]

D. Dead ends.

(1) Dead-end streets shall not exceed five hundred (500) feet in length unless, in the opinion of the Board, a greater length is necessitated by topography or other local conditions. Any proposed street which intersects solely with a dead-end street shall be deemed to be an extension of the dead-end street.

(2) Dead-end streets within commercial and industrial areas shall be provided at the closed end with a turnaround having an outside pavement line diameter of one hundred (100) feet and a property line diameter of one hundred twenty (120) feet. Within residential areas, these diameters shall be ninety (90) feet and one hundred ten (110) feet, respectively. [Amended 5-6-2003]

(3) Hammerhead turnarounds may be substituted for circular turnarounds subject to the review and approval of the Board.

(4) Roads permanently designed to be five hundred (500) feet or less shall be paved to a twenty-six-foot width within a fifty-foot right-of-way. Temporary culs-de-sac designed to access abutting undeveloped property shall be paved to a width of thirty (30) feet within a fifty-foot right-of-way.

E. Adequate access from public way. When the physical condition or width of a public way from which a subdivision has its access is considered by the Board to be inadequate to carry the traffic expected to be generated by such subdivision, the Board may require the applicant to dedicate a strip of land for the purpose of widening the abutting public way to a width at least as great as that required within the subdivision and to make physical improvements to and within such public way to the same standards required within the subdivision. Any such dedication of land for the purpose of a way and any such work performed within such public way shall be made only with permission of the governmental agency having jurisdiction over such way, and all costs of any such widening or construction shall be borne by the applicant. [Amended 7-23-1990]

10-36-060 Sidewalks

Sidewalks shall be included on both sides of the street. Sidewalks shall be at least five (5) feet wide and shall be pitched toward the gutter at three-sixteenths (3/16) inch per foot. Such walks shall be constructed twelve (12) inches from the property line. A loam and grass area shall be constructed between the sidewalk and the traveled way. The width of this grass area shall be four (4) feet. For dead-end streets, if the Board decides that a sidewalk on one (1) side only is acceptable, the sidewalk must be the complete length of one (1) side and the full circumference of the cul-de-sac.

10-36-070 Storm Sewers

A. Catch basins.

(1) Catch basins conforming to the current issue of the Massachusetts Department of Public Works Standard Specifications for Highways and Bridges shall be installed on both sides of the roadway at intervals of not more than two hundred fifty (250) feet and at all low points and sags in the roadway and at points two and fifty hundredths (2.50) feet from points of curvature and points of tangency of the edge of pavement at all intersections where necessary. All catch basins shall include a six-foot granite guttermouth.

(2) Catch basins shall be provided with a minimum sump of forty-eight (48) inches. [Amended 5-6-2003]

(3) Catch basins shall connect directly into manholes. The use of Y-connections from catch basins into main storm sewers is strictly prohibited.

(4) Catch basins shall not be interconnected except in those instances where physical conditions in the field so dictate and except with the express approval of the Board.

(5) The drainage system shall be in accordance with DEP Stormwater Management Guidelines and the Town of Northborough’s NPDES Phase II General Permit as amended from time to time. [Amended 5-6-2003]

B. Manholes.

Manholes conforming to the current issue of the Massachusetts Department of Public Works Standard Specifications for Highways and Bridges shall be provided at all changes of alignment or grade and at intervals not to exceed two hundred fifty (250) feet. Drops shall be provided in accordance with the current issue of the Massachusetts Department of Public Works Standard Specifications for Highways and Bridges.

C. Pipes.

(1) The size of storm drainage pipe shall be in accordance with the drainage computations and shall be shown on the definitive plan. In areas where the groundwater table is high or where, in the opinion of the Board, perimeter drains and cellar drains should be installed, pipe sizes as determined by the drainage computation shall be increased by one (1) increment to provide additional capacity for carrying groundwater. If the developer chooses to leave the bottom third of his drainage pipe unsealed, then the pipe shall be bedded throughout its entire length in crushed stone to a depth of not less than six (6) inches beneath the pipe and to a height of not less than twelve (12) inches over the pipe and no less than fifteen (15) inches to the finished grade of the road surface. [Amended 5-6-2003]

(2) All storm drainage pipe within roadway areas shall be reinforced concrete and there shall be a minimum cover of thirty-six (36) inches over all pipe. Drainage pipes of a material other than concrete may be substituted in easement and off-street areas only when it may be advantageous to do so and only with the approval of the Town Engineer and the Planning Board.

(3) Capacity of drainage structures shall be determined on the basis of a twenty-five-year-storm intensity. Where natural drainage courses are obstructed, culverts or similar structures approved by the Board shall be installed to restore natural drainage. Capacity of these structures shall be determined on the basis of a fifty-year-storm intensity. Masonry headwalls and/or riprap shall be installed, as approved by the Board, to prevent erosion.

(4) All drainage computations shall be submitted to the Board for review.

(5) When recharge is proposed, soil evaluation tests shall be submitted with the drainage computations verifying the suitability of the existing soils. [Amended 5-6-2003]

D. All drainage systems shall be designed so that the rate of runoff after development shall not exceed the rate of runoff prior to development. [Amended 2-11-1991]

E. Stormwater management plan shall be approved by the Conservation Commission. [Amended 10-7-1997]

10-36-080 Open Spaces [Amended 4-15-2003]

A. The Planning Board shall determine the appropriateness of all open space areas within a proposed subdivision and shall make the final determination regarding the location of the open space area(s).

B. Open space areas shall be provided in all proposed subdivisions per MGL Chapter 41 Sections 81O and 81U.

C. The following criteria shall be used by the applicant in establishing the size and location of the open space area(s):

(1) Such areas shall be of reasonable size, contiguous and not less than five percent of the total parcel area, depending upon the location and quality of the land being set aside. The minimum area acceptable shall be 40,000 square feet.

(2) If the land set aside for public use is excessively steep or wet, is not safely accessible, or is not dry for at least ten months out of the year, the Board may require additional land to satisfy this requirement.

(3) Any open space area shall contain at least the minimum amount of frontage appropriate for that particular zoning district.

(4) In areas designated as open space on the definitive plan, no disturbance or alteration shall occur to said areas. If such areas have been environmentally damaged prior to the completion of the development, the Board may require the developer to restore or improve the condition and appearance of the open space areas, and may require the posting of a cash bond to ensure such restoration or improvement.

D. No building or structure shall be erected upon such open space area for a period of three (3) years.

10-36-090 Electric, Intelligence & Communications

A. All lines shall be installed underground as specified by the Board in accordance with the regulations of the electric company.

B. Service shall be supplied to each lot from each streetlight before the subgrade is prepared.

C. The Planning Board may permit transformers, switches and other such equipment to be placed on the ground in approved locations, screened from view.

10-36-100 Sanitary Sewers

Whenever the town’s existing sanitary sewers are within one thousand (1,000) feet of a proposed subdivision, the developer shall meet the requirements of the Board of Water and Sewer Commissioners, as specified in the Town of Northborough Regulations Governing the Discharge of Waters and Wastes into the Public Sewer System. The developer may be required to construct and connect to the public sewer at his expense and subject to the joint specifications of the Planning Board and the Water and Sewer Commissioners.

10-36-110 Streetlighting

A. Streetlighting including the purchase and installation of the poles and lights, shall be supplied by the subdivider. Lights shall be located in the rear grass plot or in the median, if there is one. If streetlights are located in the median, the Board may require pedestrian lighting placed in the grass plot. [Amended 10-7-1997]

B. Streetlighting design standards:

(1) Nominal spacing: maximum of five hundred (500) feet, less on curves and other areas where safety requires, as determined by the Planning Board, after review by the Chief of Police.

(2) Nominal monitoring height: twenty (20) feet.

(3) Lamp type and size: mercury or high-pressure sodium: one hundred (100), one hundred fifty (150) or one hundred seventy-five (175) watts.

(4) Light distribution: asymmetric (1ES Type II or III).

C. Industrial and commercial lighting design standards. All outside lighting and parking-lot lighting shall be white light on poles not to exceed twenty (20) feet in height and the intensity shall not exceed the minimum required by the Massachusetts Building Code. All lighting shall be located and shielded, if necessary, to prevent light from shining on adjacent property. Fixtures or equivalent are acceptable, providing that no glare reaches adjacent properties.

10-36-120 Curb Cuts

A. Driveways in subdivisions containing one- and/or two-family dwellings only shall be at least ten (10) feet, but not greater than twenty (20) feet wide and have a curb return at the roadway of between five (5) and fifteen (15) feet in radius.

B. Curb cuts of adjacent lots shall not be closer than thirty (30) feet unless otherwise approved to be closer by the Board.

C. The driveway opening shall be located at least thirty (30) feet from the point of curve of an intersection measured along the front lot lines.

D. The driveway opening shall be at least ten (10) feet from any existing or proposed structures located within the street right-of-way, such as transformers, hydrants, catchbasins, catchbasin throat stones and transition curbs, etc. [Amended 4-15-2003]

E. Maximum grade shall be twelve percent (12%), and, within fifty (50) feet of the street line, six percent (6%).

F. The minimum sight distance for a driveway entering onto a roadway shall be a minimum of two hundred (200) feet in each direction. [Amended 10-1-1990]

G. The minimum center-line radius shall be sixty (60) feet. [Amended 10-1-1990]

H. All driveways shall exit onto the frontage street. [Amended 5-2-1994]

I. Driveway pads, consisting of a twelve (12) inch depth of crushed stone for a length of 25 feet measured from the intersection of the roadway, shall be installed prior to site development and housing construction. [Amended 10-7-1997]

10-36-130 Common Driveways

A. A common driveway to serve more than one (1) lot may be granted by a Special Permit from the Planning Board. When two lots are served by a common driveway, the following standards shall be met. When more than two (2) lots are served by a common driveway, it shall meet the Town of Northborough’s minimum road standards in addition to the following standards. In no case shall more than five (5) lots be serviced by one (1) common driveway. [Amended 10-7-1997; 4-15-2003]

(1) Minimum width: paved or graveled width of eighteen (18) feet and an easement width of twenty-four (24) feet.

(2) Maximum grade: ten percent (10%), and within fifty (50) feet of the street line, six percent (6%).

(3) Curb cut: not nearer than sixty-five (65) feet from the center-line intersections of any right-of-way.

(4) Minimum center line radius: sixty (60) feet.

(5) The minimum sight distance for a driveway entering onto a roadway shall be a minimum of two hundred (200) feet in each direction. [Amended 10-15-1990]

(6) Common driveway easement shall be located a minimum of fifteen (15) feet from abutting property lines. [Amended 10-7-1997]

(7) House numbering as issued by the Town Assessor shall occur at the following locations: for public safety purposes, a sign displaying house numbers for all the homes serviced by the common driveway shall be located at the intersection of the common driveway and the public way; house number displayed at the intersection of each individual private driveway and the common driveway; and house numbers shall be located on the front of each individual home. [Amended 4-15-2003]

B. The design of common driveways shall assure adequate safety for emergency vehicles, water service, if available, including hydrants, and adequate drainage of surface waters and provision for turnaround for use in all seasons by emergency vehicles.

(1) If the proposed common driveway is located within 2000’ of the municipal water service, the applicant shall be responsible for extending the water service for fire protection purposes to the site. If the municipal water service is not located within 2000’ of the development, each home shall include an individual water sprinkler system. [Amended 4-15-2003]

(2) For fire protection purposes, the water line shall have minimum diameter of 8". [Amended 4-15-2003]

(3) Wands shall be attached to each fire hydrant. [Amended 4-15-2003]

(4) For public safety purposes, a turn-around shall be provided at the end of each common driveway. The design and dimensions of the turn-around shall be determined by the Board based on the topography, number of lots being served by the common driveway and the length of the common driveway. [Amended 4-15-2003]

(5) If the common driveway exceeds 500’ in length, additional measures for public safety may be required by the Planning Board. [Amended 4-15-2003]

C. A declaration of covenants, easements and restrictions for the use and maintenance of said common drives may be required by the Board and shall include arrangements satisfactory to the Board concerning: roadway maintenance, snowplowing, and rubbish collection. [Amended 4-15-2003]

D. For all common driveways, the rate of a post-development runoff shall not exceed the rate of predevelopment runoff. The drainage system must be approved by the Town Engineer and the Planning Board. [Amended 10-15-1990]

E. Not more than one certificate of occupancy shall be issued until the Planning Board certifies in writing that the common driveway has been completed in accordance with the standards of this section. [Amended 4-15-2003]

F. All common driveways shall exit onto the frontage street. [Amended 5-2-1994; 4-15-2003]

10-36-140 Subdivisions in Floodplains

All proposed subdivisions shall be reviewed to determine whether they will be reasonably safe from flooding. If any part of a subdivision is located within the Floodplain District established under the Northborough Zoning Bylaw, it shall be reviewed to assure that:

A. The proposed is designed consistent with the need to minimize flood damage.

B. All ways and public utilities such as sewer, gas, electrical and water systems shall be located and constructed to minimize or eliminate the risk of damage due to flooding.

C. Adequate drainage systems shall be provided to reduce exposure to flood hazards.

10-36-150 Fire Hydrants

A. Hydrants shall be provided every five hundred (500) linear feet along the traveled way or a portion thereof on one (1) side of each street unless a greater distance is approved by the Fire Department in writing. Hydrants should also be placed at each high and low point along the proposed way whenever possible for maintaining the water system. [Amended 5-6-2003]

B. A hydrant shall, in all cases, be installed at the terminal end of each water main.

C. A hydrant shall be located on each new main within five hundred (500) feet of the nearest supply main or a fraction thereof or, if no hydrants exist, within two hundred (200) feet of the connecting point where practical at all road intersections. [Amended 5-6-2003]

C. Hydrant type, size and make, direction and pitch of threads shall be approved by the Fire Department and the Water and Sewer Department.

10-36-160 Water Mains and Appurtenances [Amended 5-6-2003]

A. Water mains and appurtenances shall be sized and constructed to serve all lots on each street within a development in strict compliance with the specifications of the Water Commissioners. The minimum size water pipe allowable, excluding hydrant connections, shall be eight (8) inches in diameter except in those instances where the Water Commissioners shall specifically authorized the use of six-inch diameter pipe for short distances where it can be ascertained that extension of the proposed system is not possible.

B. If the proposed subdivision is located within 2000’ of the municipal water service, the applicant shall be responsible for extending the water service for fire protection purposes to the site. If the municipal water service is not located within 2000’ of the development, each home shall include an individual water sprinkler system.

10-36-170 Monuments [Amended 5-6-2003]

A. All horizontal changes in the proposed roadway and the beginning and end of each curve shall be marked with Granite monuments. (see Section 10-40 Construction Standards)

B. All easements shall have concrete monuments installed at each change in direction.

C. All lot corners shall be marked with iron pins.