All land subdividers are required to construct certain public improvements, and to ensure the performance of this work, a bond will be required. All public improvements are to be constructed in accordance with the current standards, details, specifications and requirements of the Village of Lake Grove, and no work on any of the required public improvements is to be commenced by the subdivider or his agents until the construction plans and specifications have been approved by the Village Engineer. Such approval will include a stipulation that the village is to be notified at least 48 hours in advance of the work proposed, to allow scheduling of the necessary inspection by the village.
During the construction of the required public improvements and during the overall development of the entire subdivision, all existing village or county roads and streets and all adjoining private property shall be kept free of debris caused by the construction operations or by stormwater runoff from the development site. No existing street shall be damaged or have its normal traffic flow restricted or endangered in any way by equipment, material or vehicles connected with the sale or construction of a subdivision. Adequate parking and storage space for all vehicles, equipment and material required for the improvement of the subdivision shall be provided by the developer.
After completion of the public improvements covered by the performance bond and prior to the release of the bond, the subdivider's engineer shall amend the originals of the approved construction plans and indicate thereon the "AS BUILT" conditions so as to accurately reflect and show any deviations from the originally approved plans. The following certification shall also be placed on the "AS BUILT" plan:
The certification shall be dated, signed and sealed prior to submission.
Minimum public improvements shall be deemed to include clearing and grading of all new streets; paving of all streets; the installation of sidewalks in front of and in all new plots being developed by the subdivider; the installation of curbs on both sides of all new streets, whether or not the entire frontage along such new street is owned by the subdivider; adequate drainage facilities as approved by the village; sanitary sewers and/or treatment facilities as required by county authorities; street trees and landscaping; concrete monuments; street signs and park improvements. Additional improvements such as timber bulkheads, grading, retaining walls, sodded rear yard swale areas, fencing, screen planting, etc., may be required by the Planning Board if in its opinion such additional improvements are required in the interest of public health, safety or the general welfare of the present and future residents of the village.
Streets shall be of sufficient width, suitably located, related to the topography, adequately constructed to accommodate the expected traffic, afford access of fire-fighting, snow removal and road maintenance equipment, conform to the village's overall plan, cause no undue hardship to adjoining properties and provide for the orderly continuation of existing streets from adjoining properties and for the feasible projection of necessary streets into adjoining properties which are not yet subdivided. The creation of private streets will be permitted only when such streets conform to all of the criteria set forth for the creation of a public street. No street right-of-way less than 50 feet in width will be permitted, although wider rights-of-way may be required by the Planning Board if it deems it to be in the best interests of the village. Minimum permitted pavement width between faces of curb shall be 34 feet; all curbs shall have a six-inch reveal, and the top of curb shall be equal in elevation to the center line of the road for a fifty-foot right-of-way. At all street corners, the intersecting street lines shall be joined by a curve having a radius of 17 feet at the property line and 25 feet on the curbline. Whenever the algebraic difference of intersecting vertical curves exceeds 1%, a fifty-foot vertical curve shall be provided, and as the algebraic difference mounts in excess of 2%, the length of vertical curbs provided shall equal 25 times the algebraic difference. Center-line horizontal curves shall be at least 150 feet (minimum radius), and reverse center-line curves shall be separated by a minimum tangent length of 50 feet. Greater minimum radii or tangent lengths may be required if a minimum two-hundred-foot site distance cannot be obtained. A proposed cross section indicating the type of street paving, the width of pavement and the proposed curbs and sidewalks shall appear on all maps submitted. Such cross section shall also indicate the nature of all underground facilities to be installed in the right-of-way and the relative location of each in respect to the property lines and the depth of cover. The utilities shown shall include stormwater drains, sanitary sewers, water mains, underground gas and electric and any other systems proposed. In general, the materials permitted in the construction of these improvements shall be in accordance with the following tabulation:
Curb and sidewalk permitted. Curbs and sidewalks shall be constructed of concrete with a one-to-two-to-four mix which shall develop an average crushing strength of 4,000 pounds per square inch average, with 5% air entrainment, after 28 days. Sidewalks shall be at least four feet wide and set so that the back edge is six inches off the property line and two inches above the elevation of the top of the curb. They shall slope toward the street at the rate of 1/4 inch per foot. The walk shall be a minimum of four inches thick, except at the driveways, where it shall be six inches thick, extend to the back of curb and be reinforced with wire mesh. The curb shall be six inches wide, 18 inches deep, smooth wood-float finished and true to line and grade. At points where driveways provide access to the street, the curb shall be dropped so as to finish 11/2 inches above the flow line.
Water mains. Cast-iron or asbestos cement pipe of adequate strength will be permitted. All valve boxes must be accessible upon the completion of the final wearing course. All water mains and appurtenances shall be fully tested prior to the completion of the subbase preparation for the new pavement. The Board will be furnished with a layout showing the size and placement of the water mains and the location of the proposed hydrants for its review and approval. Water mains and appurtenances shall be as specified and approved by the water purveyor and the Suffolk County Department of Health, if required.
Sanitary sewers. Asbestos cement or cast iron, or other material approved by the governing county authorities.
Stormwater drains. Reinforced concrete pipe.
Manholes, catch basins and appurtenances. Precast or poured concrete with cast-iron frames or rings, and covers (heavy duty in paved areas) with catch basin inlets being of the combination curb and gutter inlet type.
The drainage plan includes detailed plans of all stormwater drainage facilities, street profiles and other utilities which may be required by the Board or other governmental agencies. These plans are considered to be an integral part of the final plat submission and are therefore the basis for the setting of the performance bonds and inspection fee. It is intended that all drainage problems within the limits of the subdivision will be completely resolved by the design as approved by the Board before any work is started. If in the event of an error on the part of the designing engineer, either of judgment or design, a drainage problem becomes apparent during the progress of the work or after the completion of the work, the Board reserves the right to stop the work and order the necessary changes to correct the situation. The Board shall be held blameless for any change so made.
The drainage plans must be prepared by a licensed professional engineer in conformance with the design criteria and standards contained herein and shall be submitted in final form, together with copies of the final plat, at least 15 calendar days prior to the date on which the final hearing is to be held. The final plat shall not be signed until the drainage plans are approved by the Village Engineer. The plans shall be prepared on Mylar sheets 24 inches by 36 inches in size. Overall plans may be scaled at one inch equals 20 feet or one inch equals 100 feet, or any convenient scale within this range. Overall location diagrams shall be provided on all plans. Profiles shall be scaled at one inch equals four feet vertical and one inch equals 40 feet horizontal. All plans shall be drawn in ink. Title boxes showing subdivision name, owner, design engineer, scale, and dates of preparation, submission, revision and approval shall be provided. Stormwater design calculation sheets must be submitted along with the plans and profiles. Overall plans covering the entire subdivision area must be provided. No section of an overall subdivision will be permitted to commence construction unless the performance bond includes provision for adequate disposal of the stormwater runoff from that section, even if this requires the immediate construction of some facilities which lie beyond the limits of the section under consideration. The plan shall indicate the following: storm sewer sizes, gradients, invert elevations and structures; manholes numbered in accordance with the design calculations, their type and invert elevation; catch basins, their type, the limits of their contributory watershed area and the area of the contributory watershed area in acres; valley gutters; stationing of road center lines at one-hundred-foot intervals and changes in grade and at catch basins or manholes; special structures; bulkheads and headwalls; recharge basins, including a separate detail of the basin scaled at one inch equals 40 feet, showing all corner grades, critical intermediate exterior grades, headwalls, sluices, bottom elevations, water level limit lines, manholes, pipe, fencing, gates and other pertinent data. The profiles must show all street names, all existing and proposed grades, intersecting streets, map lines or section lines, vertical curve data, stationing of all streets, structures, changes in grade and actual low points, all stormwater drains, structures and their lengths, types, invert elevations and gradients, and other underground utilities which will be within three feet of the proposed storm drains.
The drainage design criteria shall be as follows: For the collection system, use rational method (Q=AIR) where Q=discharge in cfs, A=tributary watershed area in acres, i=coefficient of runoff (justification for value used must be furnished), R=rainfall intensity in inches per hour as determined by R=120 over t 20 where t=the time of concentration in minutes. The pipes, conduits and ditches shall be designed in accord with Mannings formula. Recharge basins shall be designed to store the runoff resulting from an eight-inch rainfall, with a minimum runoff coefficient of 0.30. Test holes dug by a crane will be required in all proposed recharge basin sites. These holes must be dug to at least five feet below the bottom of the proposed basin or to five feet below the elevation at which suitable leaching soil is encountered, whichever of these two options results in the greater depth. If unsuitable soil is encountered at the proposed bottom elevation, it must be removed for the full depth to which good leaching material is encountered and then replaced with clean sand and gravel up to the proposed bottom elevation. All details of the required recharge basin construction shall be as shown in the details included with the aforementioned detailed construction specifications available from the Village Clerk. In fixing the required capacity of the recharge basin, allowances will be made for the dry well capacity provided at each residence. This capacity is fixed elsewhere in the village's construction requirements at the amount of water in cubic feet resulting from the fall of a one-inch rainfall over the entire roof area (horizontal projection) with 100% runoff. Manholes will be spaced at a maximum distance of 350 feet. All pipes shall be placed in a straight line between manholes. Pipes shall be located 10 feet off the center line on the south and east sides of the street. Gutter (overland) flows shall be limited to five inches in depth on the streets. All drainage easements shall be at least 16 feet in width. No more than two catch basins shall be interconnected without the use of a manhole. No natural brooks, streams, ponds, lakes or natural watercourses shall be filled in or drained. All drainage easements and recharge basins must be fixed by metes and bounds and dedicated to the village upon the completion of the necessary improvements.
Local, smaller systems may be permitted by the Village Engineer, Superintendent of Public Works and the Planning Board. If so, precast components providing a total of four inches storage minimum will be required.
The drainage plans submitted with the preliminary map need not include all of the details required for the final drainage plan, but consideration should be given to all of the final requirements at the time the preliminary map is submitted, so as to avoid or minimize changes in recharge basin areas and cuts within the beds of the streets. The preliminary map should include contours covering the entire site and for a distance of 200 feet beyond the site in all directions, at two-foot intervals, and the widths of any existing streets which abut or form a part of the subdivision. All plans shall be in the United States Coast and Geodetic Survey datum, and the plans shall so state this. The plan shall also contain a notation that all work will be done in accordance with the current standards, details, specifications and requirements of the Village of Lake Grove. The existence of streets, private rights-of-way, utility easements, drainage structures, other utility structures, marshes, streams, ponds and lakes, municipal facilities, such as sewage treatment plant or pumping stations, or wells and all available information pertaining thereto shall be included on all preliminary plans, together with indications that these features and facilities have been taken into consideration during the preparation of the preliminary plan.