The subdivision shall be designed and constructed in accordance with these subdivision regulations and, as applicable, the latest edition of the following: Massachusetts Department of Transportation (MassDOT) Project Development and Design Guide (PD&DG), MassDOT Standard Specifications for Highways and Bridges (SSHB), MassDOT Construction Standard Details, Manual on Uniform Traffic Control Devices (MUTCD), AASHTO Green Book, ITE Handbook, AASHTO Roadside Design Guide, Americans with Disabilities Act (ADA), Massachusetts Architectural Access Board (MAAB), CMR 1 Chapter 18: Fire Department Access and Water Supply,[1] Town of Ayer Water Rules and Regulations,[2] Town of Ayer Sewer Use Regulation,[3] and Town of Ayer Stormwater Rules and Regulations.
A.
Location and alignment.
(1)
All streets in the subdivision shall be designed to provide safe pedestrian and vehicular travel. Due consideration shall also be given by the applicant to the attractiveness of the street layout in order to obtain the maximum livability and amenity of the subdivision.
(2)
The proposed streets shall conform to the Master Plan as adopted in whole or in part by the Board.
(3)
Provision satisfactory to the Board shall be made for the proper extension of streets, or for access to adjoining property which is not yet subdivided, or to the acres in adjoining subdivisions.
(4)
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.
(5)
Street jogs with center-line offsets of less than 150 feet shall be avoided.
(6)
The center-line radii of curved streets shall be designed in accordance with MassDOT PD&DG and AASHTO Green Book. The minimum center-line radii of curved streets shall be 250 feet. Greater radii may be required for principal streets.
(7)
Streets shall be laid out to intersect as nearly as possible at right angles for a minimum center-line length of 125 feet from intersection of center line. No street shall intersect any other street at less than 60°.
(8)
Street rights-of-way may not be closer than 20 feet to any existing side or rear property lines.
(9)
Streets entering opposite sides of another street shall be laid out preferably opposite one another. When an offset intersection layout is proposed, the spacing between the intersecting streets shall be at least 300 feet on the same side of the street (Figure 1) and at least 125 feet on the opposite side of the street (Figure 2). Intersection spacing is a function of stopping sight distance and must be designed in accordance with appropriate policies and guidance.
Figure 1 - Spacing on Same Side of the Street  |
Figure 2 - Spacing on Opposite Sides of the Street  |
(10)
Where the angle of intersection between two streets varies more than 10° from a right angle, the radius of the curve at the curbline at the obtuse angle shall be less and at the acute angle shall be correspondingly greater than the radius specified in Section VIII.B.5.a[1] below to the extent approved or required by the Board.
[1]
Editor's Note: So in original.
B.
Cross-section. The following are standards for the design and layout of subdivisions.
(1)
Design standards.
Table 1 | ||||||
|---|---|---|---|---|---|---|
Major Street | Secondary Street | Minor Street | Private Street | Common Driveway | ||
Non-residential | Residential | |||||
Right-of-way width (feet) | 60 | 50 | 50 | 40 | 40 | 30 |
Pavement width (feet) | 34 | 28 | 26 | 22 | 22 | 18 |
Number of sidewalks | 2 | 1 | 1 | 1 | 1 | 0 |
Number of planting strips | 2 | 1 | 1 | 1 | 1 | 0 |
Maximum grade | 5% | 7% | 7% | 9% | 9% | 10% |
(2)
Classification of streets.
(a)
Major street: a street which is being used or will be used as a thoroughfare between different portions of the Town.
(b)
Secondary street: a street intercepting several minor streets, and which may carry traffic from such minor streets to a major street or community facility, including the principal access/circulation streets of a residential subdivision and all streets of a commercial or industrial subdivision.
(c)
Minor street: a street used to provide access to abutting lots, and which is not intended for use by through traffic.
(d)
Private street: an otherwise minor street with various standards waived and thus not able to be accepted by the Town.
(e)
Common driveway: A driveway that allows access to up to three detached single-family dwelling units or buildings from a public or private street. Common driveways in new subdivisions shall have a maximum length of 150 feet.
(3)
All streets in a residential subdivision shall be assumed to be secondary streets unless the developer can prove by the design of the subdivision or deed restriction that the streets will not be extended to serve other adjacent properties in the future.
(4)
Sidewalks, pathways, crosswalks, and other areas intended for pedestrian travel shall meet the requirements of the latest edition of the ADA.
(5)
All subdivision street plans and designs shall consider appropriate accommodations for all transportation system users, including pedestrians, cyclists, transit users, and motorists. Complete streets are designed and operated to enable safe access for users of all ages and abilities. Street designs should be developed with consideration to the surrounding physical environment, land uses, as well as the location of existing and other planned infrastructure to support a multi-mode transportation network. The Town of Ayer has a Complete Streets Policy, and all subdivision designs must comply with it.
(6)
Minimum site distances shall be in accordance with the latest edition, including all supplements, of the MassDOT PD&DG and AASHTO Green Book and calculations shall be provided. Such sight distances shall be provided along the length of new streets and at the intersections of all new streets and at the intersections of new subdivision streets with existing Town public streets.
C.
Grade. Grades of streets shall be not less than 0.6%. Maximum grades are shown in Table 1. For intersection approaches within 100 feet of the intersection the grade shall not exceed 4%.
D.
Dead-end streets.
(1)
Dead-end streets shall not be longer than 650 feet, excluding turnaround circle.
(2)
Dead-end streets shall be provided at the closed end with a turnaround having an outside paved road diameter of at least 80 feet with a property line diameter of at least 100 feet.
(3)
At the discretion of the Planning Board, applicants may be required to provide an appropriately sized landscaped island or bioretention area in the center of culs-de-sac to reduce impervious areas, promote groundwater infiltration and enhance the aesthetics of the subdivision.
E.
Access control and intersections.
(1)
The minimum radius at the edge of the roadway shall be 30 feet for major and secondary streets and 25 feet for minor streets.
(2)
Curb openings shall be made at street intersections for wheelchair ramps in conformance with the requirement of the MAAB.
(3)
Intersection design shall be guided by Chapter 6, Intersection Design, of the MassDOT PD&DG and pertinent AASHTO and ITE guidelines.
(4)
All intersections shall be designed with the minimum sight distances as defined by the AASHTO Green Book for Stopping Site Distance and Intersection Sight Distance.
(5)
Driveways should be located to the best advantage regarding the roadway alignment, profile, sight distance conditions, etc.
(6)
The standards call for not more than two driveways for any one property. Additional drives should not be requested unless there is a clear necessity for them.
(7)
Residential driveways shall be at least 12 feet wide and have a curb return at the roadway of two feet in radius or a granite transition if vertical granite is used. Sloped granite, when used, shall transition into driveways avoiding sharp projections. Any two driveways shall not be within 30 feet of each other at their intersections with the front lot line.
(8)
The radii of a private drive may not extend beyond the applicant's property line.
(9)
Snow storage. All culs-de-sac or dead-end streets shall include provisions for snow storage in their design.
F.
(Reserved)
G.
Common driveways.
(1)
A maximum of three single-family homes or three lots may be served by a common driveway.
(2)
The design of common driveways shall assure adequate safety and access for emergency vehicles, water and sewer service, if available, including hydrants, and adequate drainage for surface waters and provision for turnaround for use in all seasons by emergency vehicles.
(3)
All house lots served by a common driveway shall have access on the street providing frontage for that particular lot. All common drives shall enter from the street providing frontage for each lot served by the common drive.
(4)
House numbers shall be placed on a clearly visible permanent sign located at the entrance to the common driveway on the street providing frontage and at the intersection for each individual driveway.
(5)
A declaration of covenants, easements and restrictions for the use and maintenance of said common driveways shall be required by the Planning Board and shall include arrangements satisfactory to the Board concerning roadway maintenance and snow plowing. Said covenants, easements and restrictions shall be recorded at the Registry of Deeds.
(6)
No occupancy permit for a residence to be served by a common driveway shall be issued until the Planning Board certifies in writing that the common driveway has been completed to the satisfaction of the Planning Board in accordance with the Town's Subdivision Rules and Regulations.
(7)
Common driveways shall meet the standards in Table 1 and shall be laid out to intersect public streets, as well as individual driveways served, as nearly as possible at right angles. No common driveway shall intersect a street or driveway at less than 60°.
(8)
Common driveways in new subdivisions shall have a maximum length of 150 feet and a minimum clear width of 20 feet.
H.
Curbs and berms. Vertical granite curbing shall be installed at street intersections along the circumference of the roadway for the full length of the rounded curve plus a straight transition section at each end of eight feet long. Hot-mix asphalt (HMA) berm shall be located along each edge of the roadway in areas not containing granite curbing. Driveway transitions shall be as described in Subsection E, Access control and intersections.
I.
Locations of driveways in respect to intersections. Wherever possible, drives are to be set back 50 feet or more from a street corner, to be measured between the nearest edge of the driveway and the crossroad edge of the pavement. At all intersections and particularly at signalized intersections, drives shall not be approved at street corners.
J.
Driveways on rotaries or roundabouts. Driveways located directly on a rotary or roundabout are not allowed.
K.
Bridges. Bridges shall be designed in accordance with the design criteria of MassDOT.
Drainage design shall be completed in accordance with the construction specifications of the Town of Ayer Stormwater Rules and Regulations, Massachusetts Stormwater Guidelines and the following provisions:
A.
Storm drains, culverts and related installations, including catch basins, gutters and manholes, shall be installed as necessary to provide adequate disposal of surface water from all streets, driveways, roofs and other impervious surfaces within the subdivision and adjacent land and so shown on a plan designed on the basis of a 100-year storm. The definitive plan shall provide for recharging groundwater with pretreated (if applicable) stormwater in an amount equal to or exceeding pre-development conditions. Stormwater management structures shall be employed to trap pollutants and pretreat stormwater flow into any off-site wetland, water body or stormwater management structures so that said flow will, in a 25-year storm, be no higher following development than it was prior to development. The Board may authorize an increase in the peak rate or volume of stormwater flow following the applicant's demonstration that such increase will cause no environmental harm or damage to public or private property. Where the only method of drainage is via public or private property, the applicant shall furnish plans, obtain easements where necessary in the Town's behalf and assume all financial responsibility for drainage of the area. All stormwater management structures proposed shall utilize best management practices as outlined in the current Ayer NPDES Phase II Stormwater Bylaw and associated regulations.
B.
Lots shall be prepared and graded in such a manner that development of one shall not cause detrimental drainage on another. If provision is necessary to carry stormwater to or across a lot, an easement or drainage right-of-way of a minimum width of 20 feet and proper side slope of at least 3:1 shall be provided. Stormwater management shall be designed in accordance with the specifications of the Ayer NPDES Phase II Stormwater Bylaw and associated regulations. Where required by the Stormwater Authority, the applicant shall furnish evidence as to any lot or lots for which adequate provision has been made for the proper drainage of surface and underground waters from such lot or lots.
C.
Proper connections shall be made with any existing drains in adjacent streets or easements. Where property adjacent to the subdivision is not subdivided, provision shall be made for proper projection of the stormwater management structures by continuing appropriate drains to the exterior boundaries of the subdivision at such size and grade as will allow for such projection.
D.
In no case shall less than twelve-inch pipe be used for surface water drainage, and such pipe shall be larger when deemed advisable by the Stormwater Authority.
E.
Catch basins shall be provided at changes in direction, and, as far as possible, the drain between catch basins shall be laid in a straight line. Maximum spacing of catch basins shall be 250 feet, unless otherwise authorized, in specific cases, by the Planning Board.
F.
In specific cases of streets of 250 feet or less in length, drains and catch basins shall be installed and constructed by the applicant as designated by the Planning Board where, in its opinion and as recommended by the Ayer DPW, it is reasonably necessary for the public interest.
G.
The stormwater management structures shall be laid out to the satisfaction of the Stormwater Authority, its engineering consultant, and the Ayer DPW. The Stormwater Authority and Ayer DPW shall require provision of such facilities and arrangements thereof as in their opinion are reasonably necessary. The installation of the stormwater management structures, including the methods of construction and the quality of materials used, shall conform to the then-current standard specifications of the Ayer DPW, and the Ayer NPDES Phase II Stormwater Bylaw and associated regulations.
H.
Catch basins shall have a minimum four-foot sump and be four feet in diameter (inside measurements) and furnished with a proper casting approved by the Superintendent of Public Works
I.
Detention basins. A dry detention basin is an impoundment or excavated basin for the short-term detention of stormwater runoff from a completed development that allows a controlled release from the structure at downstream, pre-development flow rates. Conventional dry detention basins typically control peak runoff for two-year and ten-year, twenty-four-hour storms. They are not specifically designed to provide extended dewatering times, wet pools, or groundwater recharge. Extended dry detention basins are modified conventional dry detention basins, designed to hold stormwater for at least 24 hours to allow solids to settle and to reduce local and downstream flooding. Dry detention basins and extended dry detention basins shall be designed in accordance with the requirements of the Massachusetts Stormwater Handbook.
B.
Hydrant location and spacing shall be installed per the Ayer Water Department Rules and Regulations as well as the specifications of the Ayer Fire Department.
C.
Where a public water system is located within 400 feet of the subdivision, the subdivider shall connect to the public water system. Where a public water system is not located within 400 feet, the subdivider may install private on-lot water systems and such systems shall be designed in conformity with the standards of the Board of Health.
D.
Community-type systems or the joint use of wells shall not be allowed except in cases where there is no reasonable alternative. Such systems shall be subject to the standards of MassDEP and the Ayer DPW.
E.
The Ayer DPW, in reviewing all proposed water facilities to be located in the Floodplain District established under the Zoning Bylaw,[2] shall require that new and replacement water supply systems be designed to minimize or eliminate infiltration of floodwaters into the system.
F.
Dead-end water mains shall be avoided to eliminate standing water, except upon the express written recommendation of the Ayer DPW. Easements for future extension of the water system shall be provided, except upon the express written recommendation of the Ayer DPW.
B.
Where a public sewer system is located within 400 feet of the subdivision, applicant shall connect to the public sewer system. Where a public sewer system is not located within 400 feet, the applicant may install private on-lot sewerage systems and such systems shall be designed in conformity with the standards of the Board of Health.
C.
Community-type systems or joint use of on-lot sewerage systems shall be subject to the approval of the MassDPH.
D.
The Ayer DPW, in reviewing any proposed sewer facilities in any Floodplain District area established under the Zoning Bylaw,[2] shall require that new and replacement sewer facilities be designed to eliminate infiltration of floodwaters into the system and discharge from the system into the floodwater.
A.
Easements for utilities across lots or centered on rear or side lot lines shall be provided where necessary and shall be at least 12 feet wide for electric and telephone and at least 20 feet wide for drainage, sewerage and water.
B.
Where a subdivision is traversed by a watercourse, drainageway, channel or stream, the Board may require that there be provided a stormwater easement or drainage right-of-way of adequate width to conform substantially to the lines of such watercourse, drainageway, channel or stream and to provide for construction or other necessary purposes.
C.
All easements will be "utility easements," which will allow for the construction and maintenance of any Town service for public utilities within the boundaries of the easement.
Before approval of a plan, the Board may also, in proper cases, require the plan to show a park or parks suitably located for playground or recreation purposes or for providing light and air. The park or parks shall not be unreasonable in area in relation to the land being subdivided and to the prospective uses of such land. This is in addition to the minimum required amount of open space per Chapter 300, Zoning, § 300-10.1, Subsection 10.1.3C.
Due regard shall be shown for all natural features, such as large trees, watercourses, scenic points, historic spots and similar community assets, which, if preserved, will add attractiveness and value to the subdivision.
A.
Wherever the grade of the approved street differs from the grade of the adjacent land or where otherwise necessary for public safety, in the area beyond the sidewalk or landscaped planting strip, the developer must erect retaining walls and guardrail fences or offer slopes no steeper than one foot vertical to three feet horizontal in fill and one foot vertical to two feet horizontal in cut to ensure proper protection and lateral support.
B.
No retaining wall may have a height above finished grade greater than five feet. Where necessary, a series of retaining walls may be constructed in a terraced effect, provided the horizontal distance between the outside face of one wall is at least four feet from that of the next wall.
C.
Landscaping must be provided on slopes and on the terraces between retaining walls to reduce the visual impact of the construction. Such walls, fences, slopes and planting are subject to the Board's approval as to location, design and dimensions and must be constructed in a manner satisfactory to the Ayer DPW.
All plans submitted to the Town for review must comply with the Town of Ayer Standard Detail Sheets on file at the Ayer DPW.