A. 
Design guides. All subdivisions shall be designed and improvements made by the developer consistent with the requirements of this article. Design and construction shall:
(1) 
Reduce, to the extent reasonably possible, the following:
(a) 
Volume of cut and fill.
(b) 
Area over which existing vegetation will be disturbed, especially if within 200 feet of a river, pond or stream or having a slope of more than 15%.
(c) 
Number of mature trees removed.
(d) 
Extent of waterways altered or relocated.
(e) 
Visual prominence of man-made elements not necessary for safety or orientation.
(f) 
Volume and contamination of runoff.
[Added 8-10-2021]
(2) 
Increase, to the extent reasonably 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.
(c) 
Vistas from public ways.
B. 
Required cross section. Street construction shall conform to the required street cross section included as Exhibit A with these rules and regulations.[1] Grass strips and driveway entrances shall be so graded as to prevent surface water on the street from running onto private land.
[1]
Editor's Note: Exhibit A is included at the end of this chapter.
C. 
Extension. Reasonable provisions shall be made for extension of pavements and utilities to adjoining properties, including installation of water gates and manholes, if necessary. The developer shall not deny others connection to the water system, drainage or cable utilities, provided that they pay all costs of such connection and comply with all applicable requirements of the Town of Chelmsford or any relevant water districts.
D. 
Construction standards. In the event of any question as to construction details, specifications for the composition of material, workmanship and the method of applying materials or in the absence of established town standards, or if town standards are less demanding, standards of the Massachusetts Department of Public Works shall apply in each instance.
E. 
Compliance with Zoning Bylaw.[2] The location of buildings and other structures on land involved in subdivision or other plans submitted to the Board and the division of such land into lots shall comply with the Town Zoning Bylaw then in effect or with a variance granted by the Town Board of Appeals.
[2]
Editor's Note: See Ch. 195, Zoning.
F. 
No expense to town. All streets, footpaths, water mains and pipes, hydrants, fire alarm systems, drains, catch basins, culverts and other related facilities and municipal services shall be installed in subdivisions and completed in accordance with these rules and regulations and without expense to the town. Water mains and pipes (other than service pipes), hydrants and fire alarm systems will be installed by the appropriate water district or the town at the expense of the subdivider or will be installed by the developer and/or subdivider at his or her expense in accordance with specifications established by the water district and subject to its inspection, as directed by the Planning Board. In installing the fire alarm system within a subdivision, the developer shall connect the same to the town's existing fire alarm system at a location designated by the Fire Chief.
A. 
Horizontal design.
(1) 
Width of streets. All streets shall be designed so as to provide safe travel for vehicles and pedestrians. Streets shown on subdivision plans shall be classified as business streets, collector streets, minor streets or lanes, and minimum widths shall be the following:
Type of Street
Right-of-Way
(feet)
Pavement
(feet)
Business street
60
34
Collector street
60
30
Minor street
50
26
Lane
40
22
Off-street path
8
Varies
(2) 
Planned projections of streets into adjoining property. Streets within the subdivision shall be projected to connect with existing or proposed streets on adjoining property which come up to the boundary line.
(a) 
If adjoining property is not subdivided but is, in the opinion of the Board, suitable for eventual development, provision shall be made for proper projection of streets into such property by continuing appropriate streets within the subdivision to the exterior boundary thereof.
(b) 
Streets with temporary dead ends, laid out to permit future projection, shall conform to the provisions of alignment, width and grade that would be applicable to such streets if extended.
(3) 
Curvilinearity. Curvilinear street systems shall be used wherever feasible.
(4) 
Radii. The minimum center-line radii shall be 300 feet for business or collector streets, 150 feet for minor streets and 100 feet for lanes.
(5) 
Intersections. Street lines 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 60°. Wherever possible, street intersections shall be at least 150 feet apart. Intersections involving collector streets shall be spaced at least 400 feet apart. Curblines at intersections shall be cut back so as to provide for corner radii of not less than 30 feet at any intersection with a business or collector street and of not less than 20 feet at any other intersection. Intersections shall be located in locations that provide safe corner sight distances. Wherever possible, the sight distance shall conform to the following:
[Amended 9-28-1994]
Proposed Street
Intersecting Street
Sight Distance
(feet)
Lane
Lane
200
Any street
Minor, collector or business
300
(6) 
Dead ends. Permanent dead-end streets (a street, extension of a street or system of streets connected to other streets only at a single point) shall not serve more than 10 lots unless, in the opinion of the Board, they are necessitated by topography or other local conditions. If dead-end streets are approved, a turnaround with a radius of at least 62.5 feet to the outside of the layout will be required. Temporary dead-ends shall similarly provide for a turnaround, which may be located in part on easements over lots so long as contractual assurance is provided that upon extension of the street the terminated turnaround will be removed and replaced with loam and planting.
(7) 
Reserve strips. Reserve strips or barriers prohibiting access to streets or adjoining property will not be permitted.
B. 
Vertical alignment.
(1) 
Grades of streets. Grades of streets along the gutter line shall be not less than 1%. Vertical curves are required wherever the algebraic difference in grade between center-line tangents exceeds 1%. Maximum street grade and vertical curve length shall conform to the following:
[Amended 9-28-1994]
Type of Street
Maximum Grade
Forward Sight Distance
(feet)
Business or collector street
6%
200
Minor street
10%
150
Lane
12%
125
(2) 
Leveling areas. On any street where the grade exceeds 6% on the approach to an intersection, a leveling area with a slope of not more than 4% shall be provided for a distance of at least 50 feet from the nearest edge of the intersecting traveled way. The maximum center-line grade through a cul-de-sac shall be 5%.
[Amended 9-28-1994]
C. 
Roadway construction.
(1) 
Street grading. Stumps, brush, roots, boulders and like material shall be removed as necessary for the roadway and utilities. Wherever feasible, existing vegetation shall be retained and protected.
[Amended 7-8-1981]
(a) 
The full length and width of the proposed roadway pavement area shall be excavated or filled, as necessary, to a depth of at least 151/2 inches below the finished surface as shown on the profile. However, if the soil is soft and spongy or contains undesirable material, such as clay, sand pockets, peat, stones over six inches in diameter or any other material detrimental to the subgrade, such material shall be removed and replaced with suitable well-compacted material.
(b) 
No topsoil suitable for reuse shall be removed from the subdivision unless adequate topsoil will remain on site or is otherwise assured to provide all disturbed areas within the subdivision with a topsoil depth of at least four inches and there is also assurance that all streets from which topsoil is being removed will be brought to subgrade with approved materials within six months.
(2) 
Finished subbase.
[Amended 7-8-1981]
(a) 
Roadways shall be constructed with a foundation of at least eight inches compacted thickness of gravel borrow conforming to Massachusetts Department of Transportation Specification for Highways and Bridges M1.03.0, Type b. The source of this material (with a five-pound sample) shall be made available to the Planning Board engineer. Over this subbase material a four-inch layer of processed gravel conforming to the Massachusetts Department of Transportation Standard Specification for Highways and Bridges M1.03.1 shall be placed.
[Amended 8-10-2021]
(b) 
The gravel shall be spread in two layers, each of which shall be thoroughly watered and rolled true to line and grade with a roller of not less than 12 tons. Any depressions that appear during and after rolling shall be filled with additional gravel and rerolled until the surface is true and even. This surface shall be 31/2 inches below the proposed finished grade as shown on the profiles and have transverse grade conforming to that shown on the required cross sections.
(3) 
Finished pavement.
(a) 
After the treated roadway base has been subjected to the action of traffic for a time period specified by the Planning Board engineer, but not in excess of 30 days, a binder course of Class I-1 bituminous concrete shall be applied and compacted and rolled to a thickness of two inches with a true surface conforming to the cross section of the road. A second course of Class I-1 bituminous concrete top shall then be applied and compacted and rolled to a thickness of 11/2 inches (two inches for business streets) with a true surface conforming to the cross section of the road. Specifications for the composition of material, workmanship and the method of applying pavement material shall conform to the specifications of the town.
(b) 
Pavements shall be constructed for the full length of all streets within the subdivision shown on the plan. The center line of such pavements shall coincide with the center line of the street rights-of-way unless a minor variance is specifically approved by the Board.
(c) 
Minimum width of roadway pavements shall coincide with the requirements of Subsection A(1) of this section as determined by the Board.
(d) 
Minimum outside diameter of roadway pavement area within turnarounds on dead-end streets, if allowed, shall be 108 feet.
[Amended 9-28-1994; 8-10-2021]
A. 
General approach. Storm drains, culverts and related facilities shall be designed to permit the unimpeded flow of all natural watercourses, to ensure adequate drainage at all low points along streets, to control erosion and to intercept stormwater runoff along streets at intervals reasonably related to the extent and grade of the area being drained. To the maximum extent feasible, stormwater shall be recharged rather than piped to surface water. Peak volume and rate of runoff at the boundaries of the development must not be higher following development than prior to development.
B. 
Design basis. Storm sewers shall be based on a twenty-five-year storm, culverts for a fifty-year storm, detention basins for a 100-year storm with one foot of freeboard.
C. 
Design method. Design shall be based on Runoff Method, Soil Conservation Service Technical Release No. 20 (SCS TR-20). Refer to the Chelmsford DPW Stormwater Management Regulations for more details on design requirements. The stormwater design must meet all applicable Massachusetts DEP Stormwater Standards. Water velocities in pipes and gutters shall be between two feet and 10 feet per second and not more than five feet per second on ground surfaces. All undeveloped tributary areas shall be assumed to be fully developed in accordance with the Zoning Bylaw. The coefficient of runoff used shall not be less than 0.45 for subdivided areas.
D. 
Storm sewers. A catch basin to manhole drain configuration shall be used. All drain pipes shall be at least 12 inches inside diameter and made of reinforced concrete conforming to Massachusetts Department of Transportation specifications for Class III pipe or such higher class as may be required by depth of cover, which shall be not less than 24 inches, or high-density polyethylene (HDPE) pipe.
E. 
Structures. Generally, catch basins will be required on both sides of the roadway on continuous grade at intervals of not more than 250 feet. Catch basins shall be at least six feet deep and four feet in diameter (inside measurements), with a four-foot or greater sump below pipe invert, and shall be constructed of precast concrete units. Manhole covers and grates shall be in conformance with Massachusetts Department of Transportation specifications, designed and placed so as to cause no hazard to bicycles.
F. 
Waterways. Open brooks or tributary ditches which are to be altered shall be shaped to a cross section and gradient and provided with stream bottom hardening, all acceptable to the Planning Board.
G. 
Connections. Proper connections shall be made with any existing drains in adjacent streets or easements which prove adequate to accommodate the drainage flow from the subdivision. Runoff must be treated prior to connecting to the municipal drainage system. No increase in volume will be allowed to the municipal drainage system. In the absence of such facilities, or the inadequacy of the same, it shall be the responsibility of the developer to extend drains from the subdivision as required to properly dispose of all drainage from said subdivision in a manner determined to be proper by the Board.
A. 
The Board will not approve a subdivision plan unless water, suitable in the opinion of the Board for domestic use and fire protection, is certified by the developer's engineer to be available throughout the subdivision at a minimum standard of 500 gallons per minute open hydrant flow, with at least 20 pounds per square inch residual pressure. In addition, the Board may require the installation of booster pumps in dwellings to assure at least 20 pounds per square inch pressure throughout such dwellings.
B. 
In the event that a plan for a proposed subdivision is located in an area of town which, in the opinion of the Board, precludes the practicality of the obtainment of water supply from any water district, the Board will not approve such subdivision unless, in its opinion, upon advice of the Health Department, adequate groundwater is available at the site to supply suitable water for domestic use and, upon advice of the Fire Department, adequate provisions have been made for firesafety. Excavations made for water connections subsequent to paving shall be backfilled, compacted and surfaced under supervision of the Planning Board engineer so as to completely avoid differential settlement or displacement.
C. 
Sanitary sewers.
[Added 9-28-1994; amended 4-9-1997]
(1) 
Connection. The Planning Board will not approve a subdivision plan unless all plans submitted provide for construction of a municipal sewer system within the subdivision to be connected to the existing municipal sewer system, if available. In the event that the municipal sewer system is not available for reasonable connection of the subdivision, the Sewer Commission shall provide the proponent with a location and depth of the future connection to enable the proponent to design and construct a dry sewer line for future use by the town.
(2) 
Requirements.
(a) 
All engineering plans, designs and profiles for construction of the municipal sewer system within the subdivision shall be prepared by the proponent and shall meet all requirements and specifications of the Sewer Commission and shall be in general conformity with the existing municipal sewer system.
(b) 
All engineering plans, profiles and designs shall be reviewed by the Sewer Commission and its engineer at the proponent's expense, and a certification of approval shall be delivered by the applicant to the Planning Board prior to approval of the definitive subdivision plan. Failure to provide said certification shall be grounds to disapprove the definitive plan.
(c) 
The Planning Board shall not waive the provisions of this section without the written recommendation of the Sewer Commission that the construction of a sewer system within the subdivision is not feasible.
(3) 
Bonding.
(a) 
In determining the bonding for the project pursuant to MGL c. 41, § 81U, all costs of the sewer system, including off-site construction, shall be included and bonded.
(b) 
In the event that the location and depth of the sewer that will be servicing the subdivision are not available, the Planning Board may require the proponent to sufficiently bond the cost of the sewer line installation. The proponent will bear the cost of legal, consulting and testing fees required to arrive at an estimate for the bond.
(4) 
Sewer extension. The design and approval of the municipal sewer within the subdivision shall fall within the sole jurisdiction of the Sewer Commission. In the event that off-site construction is proposed to extend the existing sewer system to service the subdivision, the approval of the extension shall fall within the sole discretion of the Sewer Commission. Approval of the extension shall be evidenced by a fully executed sewer extension agreement between the proponent and the Sewer Commission, together with all state approvals and permits.
(5) 
Easements. The proponent shall provide all necessary sewer easements required by the Sewer Commission, and these shall be shown on the definitive plan. The final location of the sewer lines within the subdivision and the location of the connection to the municipal sewer shall remain in the sole jurisdiction of the Sewer Commission.
(6) 
Expenses. The proponent shall be responsible for reimbursement to the Sewer Commission of all costs and expenses incurred for legal and engineer consultants, inspection and testing.
A. 
Requirement.
[Amended 7-8-1981]
(1) 
All wiring, cables and other appurtenances of electric power, telephone and fire alarm systems shall be placed underground within the limits of the street right-of-way, except where such underground installations would cause undue hardship by reason of topography, subsoil conditions or other site peculiarities. The Planning Board may allow all or any part of the wiring, cables and other appurtenances to be placed above ground within appropriate easements.
(2) 
A plan shall be submitted for streetlighting of the proposed subdivision from an underground electrical distribution net. After approval by the Planning Board (fire, police and highway), the developer shall install the lighting prior to issuance of any occupancy permit.
B. 
Timing. All cable utilities shall be installed at the time of development.
C. 
Depth. Electric power cables shall be not less than 30 inches below finished grade.
D. 
Locations. Underground utilities shall be located as indicated on the required cross section. All underground utility systems, including power, communications and gas, shall have their aboveground appurtenances designed to avoid system interruption or damage in the event of flooding to base flood elevation.
A. 
Where required. Footpaths shall be installed on both sides of collector streets, on both sides of minor streets and lanes in the RC District, based on the Chelmsford Zoning Bylaw,[1] and on one side of minor streets and lanes in other residential districts, unless the Planning Board determines that no sidewalk is appropriate because a continuous system is infeasible or such walk would serve neither pedestrian convenience nor safety. Sidewalks will be required on one side of business streets.
[Amended 9-28-1994]
(1) 
In addition, the Planning Board shall, under conditions other than the above, require that the grading of the right-of-way be so executed as to make possible later additions of sidewalks without major regrading.
(2) 
Footpaths shall be not less than five feet in width, except four feet on lanes, and shall be located as close as is feasible to the street side line.
[1]
Editor's Note: See Ch. 195, Zoning.
B. 
Construction. All materials shall be removed for the full width of the footpath to a subgrade 101/2 inches below the finished grade as shown on the cross section, and all soft spots and other undesirable material below such subgrade shall be replaced with gravel (Massachusetts Department of Transportation Specification M1.03.0, Type b) and rolled. The excavated area shall then be filled with gravel (Specification M1.03.0, Type b) and rolled with a cross slope of not less than 1/4 inch nor greater than 3/8 inch to the foot. The footpath shall be constructed of bituminous concrete in two courses consisting of 11/2 inches of binder and one inch of finish. All bituminous concrete shall conform to Massachusetts Department of Transporation specifications, as amended.
[Amended 9-28-1994; 8-10-2021]
[Amended 9-28-1994]
Easements for water mains, storm drains, utilities and other purposes and their appurtenances shall be provided where such are located outside the street line and shall be at least 30 feet wide. Where a subdivision is traversed by a natural watercourse, drainageway, channel or stream, the Board may require that there be provided an easement or drainage right-of-way of adequate width to conform substantially to a line 15 feet distant from either side of the watercourse or stream. The Board may require the enclosure of any such watercourse or stream and, in the event of enclosure, may require an adequate easement to service the same. All utility (sewer, water, drain, etc.) pipes, structures and appurtenances shall be designed and constructed so as to be accessible by equipment necessary for the future operation and maintenance of the facilities.
A. 
Reservation of open space. Where it believes proper and subject to governing statutes, the Board may require the plan to provide open areas suitably located for parks, for playground or recreational purposes or for other required public facilities. Such areas shall not be unreasonable in area in relation to the land being subdivided and to the prospective public use of such land. The Board, by appropriate endorsement on the plan, may restrict the erection of a building or buildings upon such reserved areas for a period of three years without its written approval. Low-impact development (LID) features can be located within the open space.
[Amended 8-10-2021]
B. 
Preservation of trees. No trees over four inches in diameter shall be removed from a subdivision or a lot within a subdivision and no grading of a subdivision or a lot within a subdivision shall be undertaken until the Department of Public Works of the town has marked those trees of such size that may or shall be removed and those trees of such size that must be welled in order to ensure their preservation following grading.
[Amended 10-13-1999]
C. 
Shade trees. Such trees as are suitable, in the opinion of the Board, for preservation shall be preserved. Where, in the opinion of the Board, existing trees are inadequate, shade trees having a diameter of at least two inches and of a variety suitable, in the opinion of the Board, shall be planted. Such planted trees shall usually be spaced not more than 40 feet apart, in 1/2 cubic yard of topsoil satisfactory to the Board.
D. 
Planting space. There shall be a planting space between the curbline of the roadway and the footpath or street sidewalk. Said area shall be surfaced with not less than six inches of topsoil, which shall be seeded and rolled to the satisfaction of the Board. Low-impact develoopment (LID) features can be located within the right-f-way.
[Amended 8-10-2021]
E. 
Grading of slopes of streets. All slopes resulting from grading of streets are to be graded to a slope not steeper than 2:1 in cut and 3:1 in fill nor more than 3/4:1 in ledge. Slopes and other areas where topsoil has been removed shall be loamed with a topsoil satisfactory to the Board to a depth of at least six inches, seeded with a permanent grass mixture and rolled. In the event that such slopes cannot be contained within the street side lines, the subdivider shall reserve slope easements wherever feasible. If retaining walls are necessary in the opinion of the Board, they shall be constructed of reinforced concrete, stone, brick or other materials deemed suitable by the Board.
Bounds shall be placed at all angle points, at the beginning and end of all curves, at all intersections of streets and at such other places as may be required by the Board. Such bounds shall be of sound granite, not less than three feet long and not less then five inches square. The top of each bound shall be dressed and have a one-half-inch drill hole.
A. 
At front lot corners where a road bound is not required by the above, a granite bound not less than three feet long and not less than three inches square, with a one-half-inch drill hole, shall be set.
B. 
No permanent bounds shall be installed until all construction which would disturb or destroy bounds is completed.
[Amended 7-8-1981; 9-28-1994; 8-10-2021]
In some subdivisions, the Board may require infiltration trenches (see the required cross section detail[1]) along the edge of asphalt pavement for lanes, minor streets, collector streets and business streets. In all cases sloped granite curbing shall be required. All granite curbing, where required, shall be sloped granite curbing comparable to Massachusetts Department of Transportation Specification M9.04.2, Type SB. When used on a radius of 20 feet or less, curb shall be cut with radial joints. Workmanship and method of setting shall conform to the specifications of the Massachusetts Department of Transportation. Where curbing is not required, Class I bituminous concrete berms shall be placed in accordance with Massachusetts Department of Transportation Specification 470.
[1]
Editor's Note: See Exhibit A at the end of this chapter.
[Amended 9-28-1994; 8-10-2021]
Guardrails or similar devices for keeping vehicles on the road shall be installed where deemed necessary by the Board and shall be capable of withstanding without displacement the impact of an automobile traveling five miles per hour and of being readily seen by drivers. Guardrails shall conform to Massachusetts Department of Transportation specifications.
The developer shall furnish and erect street signs at the intersection of all new streets within a subdivision to designate the name of each street in the development, said signs to conform with those used by the town. From the time the construction of said street or streets is commenced until the time final approval is requested, a temporary sign of wood or masonite with appropriate letters may be used.
Before sale of a lot, the subdivider shall clean up any debris thereon caused by street construction and installation of utilities. All areas within a street destroyed or altered in construction operations shall be restored to vegetation or other finish satisfactory to the Board.
A. 
Safety.
(1) 
All precautions should be taken by the developer and the developer's subcontractors to observe common sense safety requirements. The Board designates the Planning Board engineer to report to the Board all unsafe activities in preparation of the subdivision.
(2) 
Holes greater than five feet in depth and soil piles higher than 10 feet or materials stacked in an unsafe manner shall not be allowed unless the area is adequately protected.
B. 
Inspections.
(1) 
Inspections shall be arranged for as outlined on Form H, Inspection Form.[1] The Planning Board engineer may authorize minor on-site departures from the street plan and profile and may issue a stop-work order effective for two weeks or until the next Planning Board meeting, whichever is sooner. No drainage or utility elements shall be backfilled or otherwise covered until authorized by the Planning Board engineer.
[1]
Editor's Note: Form H is available from the office of the Planning Board.
(2) 
No asphalt pavement shall be placed until a certified (by a registered professional engineer or registered land surveyor) as-built plan has been reviewed by the Planning Board engineer.
C. 
Compliance.
(1) 
It is the responsibility of the developer to ensure that the approved construction plans and these regulations are implemented. Use of qualified persons to furnish adequate and timely engineering supervision during construction is required. Surveillance and site visits by town officials shall not be construed as relieving this responsibility.
(2) 
Prior to release of security, a certificate by a registered professional engineer (civil) and a registered land surveyor acceptable to the Board must be obtained by the developer and filed, indicating that all improvements for which security is being released have been completed consistent with the approved plans and with these regulations.