9.1 Monuments
9.1.1 Permanent monuments shall be set at all corners and angle points of the subdivision boundaries and at corners of each lot; also at all street intersections and points of curvature.
9.1.2 Monuments shall be stone, metal or concrete located in the ground at final grade level, and indicated on the Final Plan. After they are set, if stone or concrete drilled holes, 1/2 inch deep shall locate the point or points described above.
9.2 Street Signs
9.2.1 Streets which join or are in alignment with streets of abutting or neighboring properties shall bear the same name. Names of new streets shall not duplicate nor bear phonetic resemblance to the names of existing streets within the municipality and shall be subject to the approval of the Board.
9.2.2 Street name signs shall be furnished and installed by the subdivider. The type, size and location shall be to the approval of the Board.
9.3 Streets
9.3.1 Layout and Construction
9.3.1.1 Proposed streets shall conform, as far as practical, to such Comprehensive Plan or policy statement as may have been adopted, in whole or in part, prior to the submission of a Preliminary Plan.
9.3.1.2 In the case of dead-end streets, where needed or desirable, the Board may require the reservation of a fifty (50) foot wide easement in the line of the street or in any practical direction to provide for continuation of utilities or access of pedestrian traffic to the next street.
9.3.1.3 Construction of streets, sidewalks, bridges, culverts and surface drainage systems shall conform to applicable standards and specifications.
9.3.1.4 Grades of all streets shall conform, in general to the terrain, and shall not be less than one/half (1/2) of one (1) percent nor more than ten (10) percent in residential areas, but, in no case, more than three (3) percent within fifty (50) feet of any intersection.
9.3.1.5 Intersections of streets shall be at angles as close to ninety (90) degrees as possible and in no case shall two streets intersect at an angle smaller than sixty (60) degrees. To this end where one street approaches another between 60-90degrees, the former street should be curved approaching the intersection.
9.3.1.6 A dead-end street, or cul-de-sac, shall not exceed six hundred (600) feet in length and shall have a turnaround at the closed end in which the radius of the traveled way shall not be less than seventy-five (75) feet.
9.3.1.7 All streets shall be provided with adequate drainage facilities, having year-round effectiveness, that will provide for the removal of storm water thereby preventing flooding of the pavement and surrounding property, and these facilities shall be so constructed as to prevent erosion of the drainage-ways.
9.3.1.8 The reserved right-of-way for all residential streets shall be not less than fifty (50) feet in width, and the paved surface shall be not less than twenty-four (24) feet; the centerlines of the right-of-way and the paved surface shall coincide.
9.3.1.9 Side slopes of filled road beds shall not be steeper than one (1) vertical foot in every three (3) horizontal feet (1 to 3 or 33 and 1/3 percent). They shall be smoothly graded, loamed and seeded by the subdivider with "Soil Conservation Mix" and a viable and effective growth produced which will prevent erosion.
9.4 Cutting and Planting
9.4.1 Cutting and Removal of Natural Vegetation
9.4.1.1 Trees, natural undergrowth, topsoil and gravel or other soil deposits in their natural state at the time of the reapplication Inspection by the Board shall be considered a part of the subdivision and, except for the removal or rearrangement required for building construction, landscaping, parking lots, recreations areas and streets or for the removal of diseased and hazardous trees, shall not be removed except in accordance with specific agreement with the Planning Board.
9.4.1.2 Cutting Restrictions: On slopes of up to ten (10) percent, no restriction; on slopes greater than 10 percent and not exceeding twenty-five (25) percent, and over, measures at a height of twenty-four (24) inches above ground level at the base, is prohibited; and on slopes exceeding 25 percent, no cutting will be permitted. The Planning Board or its representative may grant such relief from this restriction as it deems reasonable or necessary. This restriction shall be covenanted in each deed and shall be perpetual, (applicable to subdivisions with slopes of over 10%).
9.4.1.3 It shall be the responsibility of the subdivider, in all landscaped areas created by filling or redistribution of available soil, to ensure that the earth is properly compacted, fertilized, seeded and a viable and effective growth produced thereon which will prevent erosion or slippage, or both, for a period of two (2) years after the sale of the property. No side slopes of any areas so obtained shall exceed forty (40) percent (1 foot vertically to 2.5 feet horizontally).
9.5 Storm Water Management Design Standards
9.5.1 Adequate provision shall be made for disposal of all storm water generated within the subdivision, and any drained ground water through a management system of swales, culverts, underdrains, and storm drains. The storm water management system shall be designed to conduct storm water flows to existing watercourses or storm drains.
A. Where a subdivision is traversed by a stream, river, or surface water drainage way, or where the Board feels that surface water runoff to be created by the subdivision should be controlled, there shall be provided easements or drainage rights-of-way with swales, culverts, catch basins or other means of channeling surface water within the subdivision and over other properties. This stormwater management system shall be designed by a Registered Professional Engineer.
B. Drainage easements for existing water-courses or proposed drainage ways shall be provided at least thirty feet wide, conforming substantially with the lines of existing natural drainage.
C. All components of the storm water management system shall be designed to limit peak discharge to predevelopment levels for every storm between the 2-year and the 25-year, 24hour duration, Type III storm frequencies, based on rainfall data for Portland, Maine. When the subdivision discharges directly to major water body as defined in the Town of Waterboro Zoning Ordinance, peak discharge may be increased from predevelopment levels provided downstream drainage structures are suitably sized, second modeling by TR-55 or TR-20 shows hydrologic impacts to be minimal, and water quality impacts are minimal. Existing water quality of a waterbody should be investigated to analyze the nitrate and phosphorus content. The plan should then analyze the project to see if nutrient loading will occur. If after review and
based on flow rates or potentially poor water quality, detention ponds may be required.
D. The minimum pipe size for any storm drainage pipe shall be four inches. Pipe shall be bedded on 3/4 inch stone, containing stones no larger than two inches. If the fill material is approved by the town, pipe may be bedded in that material and can be covered with a geotextile liner. No clay, loam, silt, mulch, stumpage, brush or other such materials should be used for backfill. Clay or loam cap maybe used by the designing engineer if surface percolation is not desired. Perforated pipes shall be bedded six inches below the invert of the outer diameter of the pipe to a minimum of six inches over the high point of the pipe. Solid pipe shall be bedded six inches under the pipe to the spring line of the pipe. No geotextile is required for solid pipe.
E. The Planning Board may require nutrient removal structures where maintaining water quality in downstream waters is deemed important.
F. Planning Board under advisement of a registered professional engineer or other qualified professional (York County Soil and Water Conservation District) shall have the authority to waive detention requirements where benefits to the public are minimal. This shall be determined on a case-by-case basis only.
9.5.2 The Planning Board may require nutrient removal structures where maintaining water quality in downstream waters is deemed important. The storm water management system shall be designed to accommodate upstream drainage, taking into account existing conditions and approved or planned developments not yet built and shall include a surplus design capacity factor of 25% for potential increases in upstream runoff.
9.5.3 Downstream drainage requirements shall be studied to determine the effect of the proposed subdivision. The storm drainage shall not overload existing or future planned storm drainage. Planning Board under advisement of R.P.E. or other qualified professional District/SES shall have the authority to waive detention requirements where benefits.
9.5.4 Catch basins shall be installed where necessary or required, and should be located at the curb line or the invert of a ditch as required.
9.5.5 Outlets shall be stabilized against soil erosion by stone riprap or other suitable materials to reduce storm water velocity. Wherever type storm drainage system is not within the right-of-way of a public street, perpetual easements shall be provided to the Town allowing maintenance and improvement of the system.
9.5.6 The subsurface drainage system maybe incorporated with the storm water drainage system if the system is designed to incorporate both systems.
9.5.7 Maintenance responsibility for detention and nutrient removal structures must be established.
9.6 Storm Drainage Construction Standards
9.6.1 Materials.
A. Reinforced Concrete Pipe. Reinforced Concrete Pipe shall meet the requirements of ASTM Designation C-76 (AASHTO M 189). Pipe classes shall be required to meet the soil and traffic loads with a safety factor of 1.2 on the .01 inch crack strength with a Class B bedding. Joints shall be of the rubber gasket type meeting ASTM Designation C 443-70, or of an approved preformed plastic jointing material such as "Ramnek". Perforated Concrete Pipe shall conform to the requirements of AASHTOM 175 for the appropriate diameters.
B. Asbestos Cement Pipe. Asbestos Cement Pipe shall meet the requirements of ASTM Designation C-428 (AASHTOM 189). Pipe classes shall be required to meet the soil and traffic loads with a safety factor of 1.5 on the crushing strength. Joints shall be of the rubber gasket type meeting ASTM Designation D-1869-63, or of an approved preformed plastic sleeve type.
C. Corrugated Metal Pipe. Corrugated Metal Pipe shall be bituminous coated meeting the requirements of AASHTO Designation M 190 Type C for iron or steel pipe or AASHTO Designation M 196 for aluminum alloy pipe for sectional dimensions and the type of bituminous coating. Pipe gauge shall be as required to meet the soil and traffic loads with a deflection of not more than 5%.
D. ABS Pipe. ABS (Acrylonitrile-butadiene-styrene) composite pipe and fittings shall conform to the requirements of AASHTO M264 and AASHTO M 265. Perforated pipe shall conform to the requirements of AASHTO M 36, Type III.
E. Corrugated Plastic Pipe. Corrugated Plastic Pipe shall conform to the requirements of AASHTO M-252.
F. Manholes. Manholes shall be of precast concrete truncated cone section construction meeting the requirements of ASTM Designation C 478 or precast concrete manhole block construction meeting the requirements of ASTM Designation C 139, radial type. Castings shall be square cast iron sized for the particular inlet condition with the gratings perpendicular to the curb line. Bases may be cast in place 3,000 psi 28 day strength concrete or may be of precast concrete, placed on a compacted foundation of uniform density. Metal frames and traps shall be set in a full mortar bed and with tops shall conform to requirements of AASHTO M103 for carbon steel castings, AASHTO M 105, Class 30 for gray iron castings or AASHTO M 183 (ASTM A 283, Grade B or better) for structural steel.
9.6.2 Drain inlet alignment shall be straight in both horizontal and vertical alignment unless specific approval of a curvilinear drain is obtained in writing from the Board, after consultation with the Municipal Engineer.
9.6.3 Manholes shall be provided at all changes in vertical or horizontal alignment and at all junctions. On straight runs, manholes shall be placed at a maximum of 400 foot intervals.
9.6.4 Upon completion each catch basin or manhole shall be cleaned of all accumulation of silt, debris or foreign matter and shall be kept clean until final acceptance.
9.7 Certification of Construction
9.7.1 Certification of Construction. "As built" plans shall be submitted to the Road Review Committee. Upon completion of street construction and prior to a vote by the Municipal Officers to submit a proposed public way to the legislative body, a written certification signed by a professional engineer registered in the State of Maine shall be submitted to the Municipal Officers at the expense of the applicant, certifying that the proposed way meets the design and construction requirements of these regulations and the Street Design and Construction Standards Ordinance for the Town of Waterboro.
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