At a minimum, a continuous low-profile, granite edging shall be provided as an integral part of all new streets. On cul-de-sac turnarounds and at intersections, vertical granite curbing shall be required. Vertical granite curb inlets with curb transition sections shall be required at the back of catch basins, on grades over six (6) percent, and at the intersections with arterial streets.
Driveway aprons and road pavement shall be installed at the same time. Aprons shall extend from the street to the street right-of-way line. In the event that the driveway aprons can not be installed at the same time as the street construction, it shall be the responsibility of the applicant to ensure that the driveway aprons are installed prior to the acceptance of the street by Town Counsel and the Board's Designee. If a lot is undeveloped, the applicant shall curb the frontage of the lot until such time as the lot owner obtains a street opening permit.
6.11.1 Requirement:
a) Sidewalks shall be required on both sides of the street along all arterials.
b) Sidewalks shall be required on one side of the street along all local and collector streets unless the Board determines pedestrian movement is otherwise accommodated.
c)Sidewalks shall be constructed at the same time as, and in conjunction with, the roadway.
6.11.2 Design Standards:
The design and construction of sidewalks shall be based upon the nature and density of development as shown in TABLE II. All sidewalks shall be set back a minimum of 5' from the edge of the roadway.
Footnotes:
1)Meandering- following existing terrain and major features such as stonewalls, large trees, or rock outcroppings, within the street right-of-way.
(2)Standard - uniform width parallel to the street.
6.11.3 Materials:
Where new sidewalks are to be constructed in short sections to connect existing sidewalks, the new sections shall be constructed of the same materials as the existing sidewalks.
6.11.4 ADA Requirements:
All sidewalks and ramps shall conform with the Americans with Disabilities Act (ADA). Wheelchair ramps shall be constructed in conformance with the current editions of the MHD Wheelchair Ramp Standards. Wheelchair ramps shall be cement concrete, except ramps in bituminous concrete sidewalks parallel to the street at the intersection.
6.12.1 Requirements:
Monuments shall be four feet long, 6 inch square concrete or granite, and shall be installed at all street intersections, at all points of change in direction or at curvature of streets, at two (2) property corners of all new lots and at any other points where, in the opinion of the Board, permanent monuments are necessary.
6.12.2 Monument Spacing:
Monuments located in the street right-of-way shall be spaced so as to be within sight of each other, the sight lines being contained wholly within the street right-of-way limits. The maximum interval shall be one thousand feet (1000').
6.12.3 Monument Materials:
Monuments shall be standard granite markers of not less than four feet (4') in length and not less than five inches (5") square, and shall have a drill hole in the center. If subsoil conditions prohibit installation of four (4') foot monuments, with advance approval by the Board, monuments meeting alternative specifications shall be installed. Monuments shall be set flush with the finished grade.
6.12.4 Monument Certification:
No permanent monuments shall be installed until all construction which would destroy or disturb the monuments is completed. Placement and location of bounds are to be certified by a registered professional land surveyor after installation of the street, and shall be shown on the "as-built" or record plans.
6.13.1 Installation:
All utility lines, and/or other subsurface facilities within the street rights-of-way shall be installed prior to the placement of the roadway subbase materials.
6.13.2 Identification:
The applicant shall provide and install utility identification tape for all underground utility installations. The tape shall be placed in the trench a minimum of twelve inches (12") above the pipe, conduit or cable and not less than twelve inches (12") below the finished grade.
Identification tape for utilities shall be traceable, durable, and either non-biodegradable plastic or metallic, and shall be approximately six inches (6") wide by four thousandths (.004) inches, or four mil, in thickness.
The following colors shall be used:
Orange - Gas
Yellow- Electric
Green- Communications (telephone, cable, fire alarm)
Blue - Water
Red- Sanitary Sewer
6.13.3 Easements:
Wherever necessary, the Board shall require perpetual, unobstructed easements for sewers, storm drains, power lines and water mains. Such easements shall be a minimum width of thirty feet (30'), centered on the utility, and shall be indicated on the Definitive Plan by metes and bounds.
I. Easements for water, sewer, electric, telephone lines and drainage piping or channels shall be provided at locations determined by the Board and the Department of Public Works for the provision or extension of utilities within the development or to adjacent properties. Such easements shall be no less than twenty (20) feet in width.
II. Where a subdivision is traversed by any open water course, drainage way, channel or stream, an easement shall be provided which substantially conforms to the lines of such features for the purpose of protection against encroachment or alteration. Such easements shall be at least thirty (30) feet in width, unless determined otherwise by the Board or Department of Public Works.
Where such easement or any part thereof crosses or appears on any subdivision lot in the development, the deed for said lot shall provide a restriction which shall run with the lot which prohibits any encroachment or alteration within such easement.
III. Utility easements into or crossing any open space or protected area shall be prohibited unless approved by the Board upon the recommendation of the Department of Public Works.
IV. Where easements have been approved entering into or crossing open spaces or protected areas they shall be restored to reflect as nearly as possible the conditions existing prior to the easement. Vegetative visual buffering required by the Planning Board in such easements shall be the responsibility of the developer and shall be reflected in the subdivision performance guarantee.
V. Easements for access to parks and conservation lands abutting a proposed subdivision may be required by the Board. These easements shall be at a width determined by the Board to be sufficient for their purpose but will not normally exceed 30 feet in width.
VI. The developer may be required to obtain off-site drainage easements when, in the Board's opinion, the subdivision will cause an increase or change in the surface water volumes or velocities, either through open channels or through culverts into or onto any abutting properties.
VII. Where the easement is accessible from the street, the side slope shall be no greater than four feet (4') horizontal to one foot (1') vertical. The first twenty feet (20') of the easement from the back of sidewalk, or edge of roadway, shall have a twelve inch (12") deep base of gravel subbase material beneath the topsoil to support maintenance equipment .
Storm water run-off shall be disposed of through a combination of storage and controlled release, as indicated in the Rules and Regulations Governing Storm Water Management (See Appendix V) Drainage systems shall be designed according to the following principles and criteria:
6.14.1 Peak Flows:
Property shall be developed in such a manner as to maximize storm water recharge on the site and to minimize direct overland run-off into adjoining streets and watercourses. Peak flows and run-off at the boundaries of the subdivision shall be no higher following development than before development, for the 10 and 100 year storm events.
6.14.2 Capacity:
Drainage systems shall have adequate capacity to carry all storm water run-off presently flowing through the subdivision, as well as to dispose of any additional run-off generated by the proposed development up to and including the run-off from a one hundred (100) year storm using the following methods: a) the flow from storms of up to a twenty-five (25) year frequency and a twenty-four (24) hour duration shall be conveyed through the storm drain system on the subdivision site. Storm drain piping and grate inlets shall be designed for a 25 year storm event; b) Detention facilities and culverts shall be provided to accommodate all run-off, up to and including the runoff generated by the one hundred (100) year, twenty-four (24) hour storm. As a minimum, detention basin routing calculations shall be prepared for the ten (10) and one hundred (100) year storm events.
6.14.3 Release Rate:
The combination of storage and design release rate shall not result in a storage duration of greater than seventy-two (72) hours. Maximum depth of storm water detention/retention areas shall be four feet (4').
6.14.4 Outlet Structures:
Outlet control structures shall be designed as simply as possible and shall require as little maintenance as possible for proper operation.
6.14.5 Emergency Overflow:
Each storm water detention area shall be provided with a method of emergency overflow in the event of a storm in excess of the one hundred (100) year frequency type.
6.14.6 Natural Patterns:
Natural drainage patterns shall be used wherever possible. All existing watercourses shall be left as existing unless approval to alter them is obtained through the Conservation Commission. All new open watercourses shall be protected from erosion with seeded, sodded, rip rapped, stone lined or other treatment required for the projected volume and velocity of flow.
6.14.7 Alteration:
Any alteration of land on the site shall be such that changes in existing patterns of drainage shall not affect properties outside the subdivision by increasing the amount or rate of peak flow as designated by the Wetlands Protection Act.
6.14.8 Structured Systems:
If soil conditions or topography make natural drainage systems impractical and existing drains in adjacent streets or easements have adequate capacity to accommodate the drainage flow from the subdivision, a structured system shall be used and appropriate connection to the existing Town drainage system shall be made.
6.14.9 Calculations:
Hydraulic calculations, prepared by a registered professional engineer, shall note the specific engineering and/or computer program to be used. Hydraulic calculations shall be submitted to substantiate all design features of any proposed drainage system. Computations for run-off shall be made in accordance with standard engineering practice, acceptable to the Board's Designee. Pipe systems shall be designed to provide self-cleaning flow velocities.
The hydrology calculations information shall include the following information, as a minimum:
1. Runoff area boundaries shown on a plan
2. Methodology used
3. C factors and I values used for existing and proposed conditions
4. Soil conditions / ground water
The hydraulic calculations shall show the following information, as a minimum:
1. Capacity and projected volume of each catch basin or other inlet grate
2. Pipe size calculation
3. Detention / retention pond calculations including outlet structure as applicable
4. Total suspended solid (TSS) removal rates
5. Infiltration calculations as applicable
6. Gutter flow calculations
7. Culvert analysis and calculation as applicable
6.14.10 Detention / Retention Basin Side Slopes:
Basin area side slopes shall be kept as close as possible to natural land contours, i.e. ten percent (10%) or less wherever possible. A maximum 3:1 side slope shall be constructed for the interior of the basin areas. For security purposes fencing may be required by the Board. Drainage basins shall be designed to facilitate access for maintenance vehicles and personnel.
6.14.11 Drainage Easements:
If it is necessary to carry drainage across lots within the subdivision, storm drainage easements shall be provided, of such width and construction as will be adequate to accommodate the volume and velocity of the run-off. However, no such easement shall be less than thirty feet (30') in width.
If a proposed drainage system would carry water across land outside the subdivision boundaries to an approved outfall, appropriate drainage rights shall be secured by the applicant at the applicant's expense, and shall be referenced on the Definitive Plan.
6.15.1 Installation:
The applicant shall be responsible for installing water facilities, including, but not limited to water supply, pipes, hydrants, hydrant markers, gates, valves, and all other related appurtenances, in accordance with the Regulations and Master Plan of the Water Department. Any extension of an existing pipe and construction of new pipes requires approval from the Water Department. Building service pipes and appurtenances from the system piping to the exterior line of the street right-of-way shall be constructed for each lot unless the Board of Health has approved individual wells. Said water facilities shall be shown on the definitive plan.
6.15.2 Fire Hydrants:
Fire hydrants shall be required for all a subdivisions. Fire hydrants, with hydrant markers, shall be located not more than five hundred feet (500') apart; shall be approved, in writing, as to location by the Fire Chief and the DPW; and shall be shown on the Definitive Plan.
6.15.3 Extensions:
Reasonable provisions shall be made for extension of the water system and pipes to adjoining property, including installation of water gates. Appropriate easements may be required.
6.15.4 Additional Alternative System of Water Supply/Fire Protection:
If the municipal water supply is available, but the minimum required flow is not available, in addition to extending the municipal water system, the applicant shall propose an alternative system for providing water supply for fire protection.
6.15.5 Municipal Water Supply Not Available:
If the municipal water supply is not available to the subdivision, the applicant shall propose an alternative method of providing water supply for fire protection. Water for fire fighting may be supplied by natural or man-made bodies of water. The surface of each pumping access point shall be adequate to support at least 42,000 pound gvw vehicles at all times of the year. Provisions shall be made so that such water suction points shall be visible and useable in all weather conditions. Each dry hydrant which may be exposed to damage by vehicular traffic shall be protected by suitable barriers.
