Town of Marblehead, MA Design Standards

All subdivisions shall adhere to the principles of compatible land use, sound planning, and good engineering and shall meet the requirements of public safety, including reasonable precautions against possible natural disasters, traffic safety and convenience, adequate water supply, stormwater drainage and protection against flooding, and sanitary sewage disposal, and shall be designed with due regard to the rights, health and welfare of the residents of the Town, including the future residents of such subdivisions.

It is a policy of the Town and a major objective of the Board that all subdivisions designed and improvements made by the subdivider shall accomplish the following:

(1)

Reduce, to the extent reasonably possible:

(a)

Volumes of cut and fill and excessive grading.

(b)

Area over which existing vegetation will be disturbed (especially within 100 feet of wetlands).

(c)

The number of healthy, mature trees removed.

(d)

The extent of waterways altered or relocated.

(e)

Visual prominence of man-made elements which are not necessary for safety or orientation.

(f)

Erosion and siltation; soil loss or instability.

(g)

Flood damage.

(h)

The number of driveways exiting onto existing streets.

(i)

Disturbance of important wildlife habitats, outstanding botanical features, geologic features, and scenic or historic places.

(j)

Visibility of building sites from existing streets.

(k)

Blockage of vistas through new development.

(l)

Removal of stone walls.

(m)

Alteration and obstruction in groundwater or surface water or naturally occurring chemical constituents.

(2)

Increase, to the extent reasonably possible:

(a)

Vehicular use of collector streets to avoid traffic on streets providing house frontages.

(b)

Visual prominence of natural features of the landscape.

(c)

Legal and physical protection of views from public ways.

(d)

Street layout facilitating solar orientation of houses.

(e)

Use of curvilinear street patterns.

(f)

Attractiveness of the street layout in order to obtain maximum livability and amenities of the subdivision.

(g)

The ability to safely pass through the way during construction.

(h)

The preservation of the open rural character of the Town.

(i)

Water quality, both groundwater and surface water.

Compliance with other requirements. All subdivisions shall be laid out so as to conform to these rules and regulations and to the requirements of other boards and officials of the Town acting within their jurisdiction.

Wetlands protection. The Board may condition its approval of a definitive plan upon the issuance of an order of conditions from the Marblehead Conservation Commission or the Massachusetts Department of Environmental Protection.

Compliance with Marblehead Zoning Bylaws. All proposed streets and ways shall comply with the Town's Zoning Bylaws in effect at the time of plan application. All proposed lots shall comply with those dimensional requirements set forth in the same Zoning Bylaws.[1]

[1]

Editor's Note: See Ch. 200, Zoning.

Earth removal. The approval of a definitive plan by the Board shall not be construed as authorizing the removal of earth material from the premises, even though the approval is in connection with the construction of streets shown on the definitive plan. All earth removal within subdivisions shall be in accordance with the Town's Zoning Bylaw for earth removal.

Access through another town. Any access to a proposed subdivision through another town shall require the certification of that town that the street is in accordance with the rules and regulations of that town's planning board, and that the bond posted is adequate, and that the access is adequate for the expected traffic. The entire street shall be designed in accordance with the most restrictive specifications.

Street connection. Subdivisions containing 16 or more lots shall have at least two noncontiguous connections with a street or streets, either existing or shown on an approved subdivision plan, for which a performance guarantee has been filed with the Board. These two noncontiguous connections shall be separated by a distance of at least 600 feet.

Board's prerogative. Where the design standards and/or construction specifications as described in these rules and regulations are not specific enough, it shall be the Board's prerogative to impose design and/or construction requirements as deemed necessary and proper. If in the opinion of the Board the proposed design is inadequate given the specific site conditions, the Board shall specify the appropriate requirement(s) for design and/or construction.

All streets in the subdivision shall comply with policies and standards per the American Association of State Highway and Transportation Officials (AASHTO) publication, "A Policy on Geometric Design of Highways and Streets" (latest edition). Major streets should, as far as practicable, provide for the continuation or projection of existing principal streets.

Classification of streets.

(1)

Major street: a street which, in the opinion of the Board, is being used or will be used as a thoroughfare between different portions of the Town of Marblehead, or which will otherwise carry a heavy volume of traffic (generally 1,500 vehicle trips per day). The design speed shall be 50 miles per hour.

(2)

Secondary street: a street intercepting one or more minor streets and which, in the opinion of the Board, is used or will be used to carry a substantial volume of traffic (generally 400 vehicle trips per day) from such minor street(s) to a major street or community facility, and normally including the principal entrance street of a large subdivision or group of subdivisions, and any principal circulation street within such subdivision. The design speed shall be 40 miles per hour.

(3)

Minor street: a street which, in the opinion of the Board, is being used or will be used primarily to provide access to abutting lots, carrying fewer than 400 vehicle trips per day (but greater than 150 vehicle trips per day) and/or less than 3,000 feet in length, and which will not be used for through traffic. The design speed shall be 30 miles per hour.

(4)

Lane: a street which, in the opinion of the Board, is being used or will be used primarily to provide access to a small number of abutting lots, carrying 150 (or fewer) vehicle trips per day. Lanes are typically used, but not limited to, dead-end streets. The design speed shall be 20 miles per hour.

Street design.

(1)

Location.

(a)

Reserve strips prohibiting access to streets or adjoining property shall not be permitted, except where, in the opinion of the Board, such strips shall be in the public interest.

(b)

Proper provision, suitable to the Board, shall be made by means of easements for the projection of streets and ways, or for access to adjoining property which is not yet subdivided.

(c)

Street jogs with center-line offsets of less than 150 feet shall be avoided.

(d)

Streets shall be laid out so as to intersect as nearly as possible at right angles. No street shall intersect any other street at less than 60º.

(e)

Proposed subdivision streets intersecting major (or secondary streets) shall have a minimum sight distance of 300 feet measured from the driver's seat stopped at the intersection looking in either direction to oncoming traffic.

(f)

Streets shall be laid out so as to intersect at intervals which permit the block size to be in the range of 600 to 1,200 feet in length. In lieu of actual construction of cross street, the Board may approve an easement for a future street.

(2)

Horizontal alignment.

(a)

The center line of the pavement shall coincide with the center line of the way.

(b)

The minimum center-line radii for horizontal curves shall be as follows:

[1]

Major streets: 530 feet.

[2]

Secondary streets: 290 feet.

[3]

Minor streets: 125 feet.

[4]

Lane: 100 feet.

(c)

Reverse horizontal and vertical curves are allowed for minor streets and lanes and do not require separation by tangents between the curves. Major and secondary streets require a one-hundred-foot tangent be placed between the reverse curves, except where the radius of curvature for both curves is greater than 1,060 feet for major streets and greater than 580 feet for secondary streets.

(d)

Wherever possible, center-line horizontal curve (beginning and end of curve) points shall coincide with center-line vertical curve (beginning and end of curve) points.

(e)

The distance between curbline and property line at any intersection shall be the same as along the approach portions of the intersecting streets. Property lines at street intersections shall be rounded (or cut back) accordingly to comply with this regulation. The curb radius at all intersections shall not be less than 25 feet, with the exception that the intersection of two major streets shall have a curb radius not less than 50 feet.

(3)

Width. The minimum width of pavements and rights-of-way shall be as follows:

(a)

Major street: 70 feet right-of-way and 34 feet pavement.

(b)

Secondary street: 60 feet right-of-way and 28 feet pavement.

(c)

Minor street: 50 feet right-of-way and 24 feet pavement.

(d)

Lane: 40 feet right-of-way and 24 feet pavement.

(4)

Grade.

(a)

The maximum and minimum longitudinal center-line grades shall be as follows:

[1]

Major streets: 5% maximum, 0.5% minimum.

[2]

Secondary streets: 6% maximum, 0.5% minimum.

[3]

Minor streets: 8% maximum, 0.5% minimum.

[4]

Lane: 10% maximum, except that on north facing slopes the maximum shall be 8%, 0.5% minimum.

(b)

Where curves and grades combine to create potentially dangerous driving conditions, the Board will require a suitable amount of superelevation of the curves or other protection mechanisms.

(c)

The minimum length of a vertical curve shall not be less than 100 feet.

(d)

On any street intersection, a leveling area with a center-line slope of not greater than 2% shall be provided for a distance of at least 100 feet from the nearest edge of intersecting road pavement.

(e)

All changes in grade exceeding 0.5% shall be connected by vertical curves. The minimum length of a vertical curve shall be designed in accordance with the following AASHTO standards:

	Safe Sight Stopping Distance (feet)	K Value for Crest Vertical Curves (feet)	K Value for Sag Vertical Curves (feet)
Major streets	400 to 475	110 to 160	90 to 110
Secondary streets	275 to 325	60 to 80	60 to 70
Minor streets	200	30	40
Lanes	125	10	20

NOTE: Length of vertical curve (L) = K (g1% - g2%)

For measuring safe sight stopping distance, the height of the eye is 3.5 feet and the height of the object is 0.5 foot.

(5)

Dead-end streets (cul-de-sac).

(a)

Dead-end streets (or streets connected to a throughway at only a single point, whether temporary or permanent) shall be not longer than 500 feet and not shorter than 250 feet measured from the center line of the intersecting street, along the actual center line of the cul-de-sac, to the center point of the cul-de-sac. Refer to cul-de-sac schematic in the Appendix.[1] A greater length requires a special permit from the Marblehead Zoning Bylaw.[2]

[1]

Editor's Note: The appendix material is on file at the Planning Board office.

[2]

Editor's Note: See Ch. 200, Zoning.

(b)

Dead-end streets shall provide (at the closed end) a turnaround having an outside roadway diameter of at least 100 feet and a property line diameter of at least 130 feet.

(c)

The unpaved portion of a cul-de-sac shall have a minimum radius of 50 feet and shall be landscaped except where trees or shrubs exist or where desirable natural features exist to be preserved. This cul-de-sac island shall be curbed as per § 258-20F(7)(a).

Utility design.

(1)

General.

(a)

All storm drains and electric and telephone facilities (exclusive of transformers) within the limits of a way shall be placed underground per utility company specifications in locations shown on typical street cross section (Appendix) and shall be installed after the way has been excavated to subgrade.

(b)

Connections for 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 where the lot shall be a designated open space or playground or used for any other purpose for which such connections shall not be required.

(c)

Where adjacent property is not yet subdivided or where the applicant's property is not being subdivided at the same time, provision shall be made for the extension of the utility system by continuing mains the full length of the streets to the exterior limits of the subdivision at such pipe slope and size as will permit their proper extension at a later date.

(2)

Lighting. The subdivision shall supply streetlighting which will be located on a suitable post which may be of concrete, wood or aluminum and at a height of 15 feet or more as approved by the Board. The streetlighting shall be designed in accordance with the current edition of the I.E.S. Lighting Handbook or designed to standards acceptable to the Board. Luminaries shall be of the indirect, shielded type. Streetlights shall be located at each intersection and at the closed end of each cul-de-sac.

(3)

Storm drainage system.

(a)

A complete and adequate storm drainage system shall be so laid out and of sufficient size as to permit unimpeded flow of all natural waterways, provide adequate drainage of all surface and subsurface water of the street system so that water does not accumulate thereon, intercept stormwater runoff from the adjoining land and eliminate unnatural accumulation of water on any portion of the subdivision or surrounding property.

(b)

A watershed analysis shall be performed by a registered civil engineer (and submitted with the definitive plan) for pre- and post-development conditions to show flooding impacts for the one-, ten-, and one-hundred-year storm events using SCS TR-55 and/or TR-20 stormwater modeling methods. The design of the stormwater management system for the subdivision shall not increase the volumes or rates of discharge off site. Note that if the stormwater discharge point is within 100 feet of wetlands, the Conservation Commission must also approve the design per the Massachusetts Wetlands Protection Act.[3]

[3]

Editor's Note: See MGL c. 131, §§ 40 and 40A.

(c)

Detention/retention ponds shall be designed by a registered civil engineer and based on the latest edition of Urban Hydrology for Small Watersheds, Technical Release No. 55 by the Engineering Division, Soil Conservation Service, United States Department of Agriculture. The SCS TR-55 method (or SCS TR-20 where applicable) shall be used to generate hydrographs used in the design of detention and/or retention ponds or similar water storage facilities and/or structures.

(d)

The storm drainage system shall include catch basins, manholes, culverts, drain lines, leaching systems, headwalls, flared ends and such other structures as may be required to complete the system. Grassed swales are considered as part of the storm drainage system. Calculations for determining the size of street drains (pipes between CBs and MHs) shall be designed using the Rational Method for the ten-year design storm. Calculations for culverts shall be designed using Hydraulic Design Series No. 5 for the twenty-five-year storm when the contributing watershed area is less than 50 acres and the fifty-year storm when the watershed area is 50 acres or more.

(e)

Catch basins shall be located, one on each side of the crowned roadway, and at all low points, and at intervals of not more than 400 feet and at or near the corners of the roadway at intersecting streets. Each catch basin shall connect directly to a manhole and shall be per MDPW standards. Catch basins shall not be located at a driveway entrance.

(f)

Manholes shall be located at all drain line changes in direction, either horizontally or vertically, and at the intersection of two or more drain lines, or located so that no drain line of a length greater than 400 feet would exist without either a catch basin or manhole. Each manhole shall be per MDPW standards.

(g)

All culverts shall have a field stone headwall at each end per MDPW standards. All outfall pipes shall have a field stone headwall (for pipes exceeding fifteen-inch diameter) or a flared end section (for twelve- and fifteen-inch diameter pipes) per MDPW standards. Scour protection (in the form of stone for pipe ends per MDPW standards) shall be provided as required to reduce velocity of discharge to below two feet per second and to minimize erosion.

(h)

In areas where the finished grade of the roadway is less than four feet above the water table or in other areas where, in the opinion of the Board, the subgrade must be drained, a system of subdrains may be required. The subdrain system shall have a positive outfall and be designed per MDPW standards.

(i)

All drain lines shall be reinforced concrete Class III or better and a minimum of 12 inches in diameter and shall be laid on a slope of not less than 0.5%. The minimum design velocity shall be two feet per second (self-cleaning velocity) and the maximum design velocity shall be 10 feet per second. Provision shall be made for the disposal of surface water intercepted or collected by the system in such manner that no flow is conducted over Town ways, or over land of others, except that flow rate and flow quantity which previously existed in that location.

(j)

Stormwater shall be directed to enter the most environmentally suitable area.

(k)

The minimum earth cover on top of drain lines and culvert pipes is three feet. Ductile iron drain pipe or concrete encasement may be substituted for a reduction in cover.

(l)

Where applicable, backwater effects shall be taken into account in the design of the storm drainage system.

(m)

Culverts or drains proposed to have bar grates to prevent debris from entering at their inlets shall be designed with their inlet capacity reduced 25%. Bar grates shall be provided on the inlet and outlet ends of all pipes over 15 inches in diameter.

(n)

Culvert and drain design shall be based on a Manning roughness coefficient "n" equals 0.013.

(o)

Individual lot grading and drainage shall be designed and constructed in such a manner that development of one lot will not be detrimental (or cause flooding or erosion of soils) to another lot or any abutting property.

(p)

The Board may require the subdivider to eliminate or remove any other stormwater flowing to and from the proposed subdivision which is otherwise not taken care of.

(q)

Street drainage shall be designed such that pipes flow without surcharge.

(r)

Grassed swales within the road right-of-way may be designed. The swales shall be able to carry the ten-year storm without spillage on abutting property. The minimum longitudinal slope shall be 0.5% and the maximum shall be designed so that velocities do not exceed three feet per second. The use of grassed swales should be designed to retain the "first flush" where possible, thus reducing the size of the required detention and retention basins.

(s)

Design criteria for stormwater leaching basins shall be the same as that criteria established in Title V.

(4)

Fire protection. Provision shall be made for fire protection for the proposed buildings within a subdivision per the requirements and specifications of the Town Fire Department.

(5)

Easements. The following easements shall be referred to on the plan (by bearings and distances) and run with the title of land:

(a)

Utility easements. Easements for utilities carrying underground wires (where required) running across lots or on rear or side lot lines shall be provided where necessary and shall be at least 20 feet wide.

(b)

Drainage easements. Where a subdivision is traversed by a watercourse, drainageway, channel or stream, the Board may require a stormwater easement or drainage right-of-way of adequate width (20 feet minimum) and proper side slope and surface to facilitate maintenance.

(c)

Access easements. Access easements and rights-of-way to a park, open space and/or conservation land or for use by emergency vehicles shall be secured for the benefit of the Town and shall be a minimum of 25 feet wide.

(d)

Footpath easements.

[1]

Footpath easements shall be secured where applicable for the benefit of the Town and shall be at least 10 feet wide.

[2]

Location of footpaths. When streets in excess of 750 feet in length are incorporated in the subdivision (or in other cases per the discretion of the Board or Conservation Commission), footpaths shall be laid out and constructed to connect the subdivision street with an adjacent street, public land, or park at a point approximately midway between streets, intersections or turnarounds.

(e)

Sight distance easements. Where there is the possibility of a sight obstruction at an intersection or curve, an easement shall be secured for the Town which will ensure proper safety of pedestrian and vehicular traffic.

(f)

Slope easements. Where terrain outside the right-of-way warrants additional grading to meet the intent of these rules and regulations, a temporary slope easement shall be established for the construction of the slope and any retaining structures. Following its construction, the slope easement shall be disbanded and the owner of such slope shall maintain the slope and structures to ensure no trespass of eroded material onto the way or abutting property.