There is a mutual responsibility between the subdivider and the Subdivision Agent to divide the land so as to improve the general use pattern of the land being subdivided.
The Subdivision Agent shall not approve the subdivision of land if, from adequate investigations conducted by all public agencies concerned, it has been determined that, in the best interest of the public, the site is not suitable for platting and development purposes of the kind proposed.
A. 
To ensure that residents will have sufficient land upon which to build a house which is reasonably flood-free, the Agent may require the subdivider to provide elevation and flood profiles sufficient to demonstrate the land to be completely free of the danger of floodwaters.
B. 
A benchmark must be located in or near any division of land that is adjacent to any floodplain, approved by the Agent for location and delineated on the plat with reference to the location and elevation.
All required improvements shall be installed by the subdivider at the subdivider's cost. The subdivider's performance bond shall not be released until all construction has been inspected and approved by the appropriate engineers. All improvements shall be in accordance with the following requirements:
A. 
Streets. All streets in the proposed subdivision shall be designed and constructed in accordance with the following minimum requirements by the subdivider at no cost to the locality:
(1) 
Alignment and layout. The arrangement of streets in new subdivisions shall make provision for the continuation of existing streets in adjoining areas. The street arrangement must be such as to cause no unnecessary hardship to owners of adjoining property when they plat their own land and seek to provide for convenient access to adjoining areas. The streets shall be extended by dedication to the boundary line of such property. Half streets along the boundary of land proposed for subdivision will not be permitted. Wherever possible, streets shall intersect at right angles. In all hillside areas, streets running with contours shall be required to intersect at angles of not less than 60°, unless approved by the Subdivision Agent upon recommendation of the Highway Engineer. The subdivider shall also dedicate additional right-of-way as required by the Virginia State Department of Transportation for future improvements.
(2) 
Service drives. Whenever a proposed subdivision contains or is adjacent to a limited access highway or expressway, provision shall be made for a service drive or marginal street approximately parallel to such right-of-way at a distance suitable for an appropriate use of the land between such highway and the proposed subdivision. Such distances shall be determined with due consideration of the minimum distance required for ingress and egress to the main thoroughfare. The right-of-way of any major highway or street projected across any limited access highway or expressway shall be of adequate width to provide for the cuts or fill required for any future separation of grades.
(3) 
Approach angle. Major streets shall approach major or minor streets at an angle of not less than 80°, unless the Agent, upon recommendation of the Highway Engineer, shall approve a lesser angle of approach for reasons of contour, terrain or matching of existing patterns.
(4) 
Minimum widths. The minimum width of proposed streets measured from lot line to lot line shall be as specified by the Virginia Department of Transportation for acceptance into the State Secondary System.
(5) 
Construction requirements. All streets shall be constructed to requirements as specified by the Virginia Department of Transportation for acceptance into the State Secondary System. At the time of filing the preliminary plat, the subdivider shall also present to the Subdivision Agent complete plans and specifications for soil erosion and sedimentation controls.
(6) 
Culs-de-sac. Generally, minor terminal streets (culs-de-sac) designed to have one end permanently closed shall serve no more than 20 lots. Each cul-de-sac must be terminated by a turnaround of not less than 100 feet in diameter.
(7) 
Alleys. Alleys should be avoided wherever possible. Dead-end alleys, if unavoidable, shall be provided with adequate turnaround facilities as determined by the Subdivision Agent.
(8) 
Private streets and reserve strips. There shall be no private streets platted in any subdivision. Every subdivided property shall be served from a publicly dedicated street. There shall be no reserve strip controlling access to streets.
(9) 
Names. Proposed streets which are obviously in alignment with other already existing and named streets shall bear the names of the existing streets. In no case shall the names of proposed streets duplicate existing street names, irrespective of the use of the suffix street, avenue, boulevard, driveway, place, land or court. Street names shall be approved by the Subdivision Agent. Names of existing streets shall not be changed except by approval of the governing body.
(10) 
Identification signs. Street identification signs of a design approved by the Highway Department shall be installed at all intersections, readable from either side.
B. 
Monuments. All monuments required by this chapter must be installed by the subdivider and shall meet the minimum specifications hereinafter set forth. Upon completion of subdivision streets, sewers and other improvements, the subdivider shall make certain that all monuments required by the Agent are clearly visible for inspection and use. Such monuments shall be inspected and approved by the Agent before any improvements are accepted by the governing body.
(1) 
Concrete monuments. Concrete monuments four inches in diameter or square, two feet long or iron pipes, or their equivalent, with a flat top shall be set where lot lines intersect streets or no more than 10 feet set back from said street and at all points where the street line intersects the exterior of the subdivision, and at right angle points, and points of curve in each street.
(2) 
Iron pipe (or equivalent). All other lot corners shall be marked with iron pipe not less then 1/2 inch in diameter and 24 inches long and driven so as to be flush with the grade line. When rock is encountered, a hole shall be drilled four inches deep in the rock, into which shall be cemented a steel rod 1/2 inch in diameter, the tip of which shall be flush with the grade line.
C. 
Water facilities. Where public water is available, the service shall be extended by the subdivider to all lots within a subdivision, including fire hydrants in accordance with the design standards and specifications for water construction and improvements in the County and meeting the approval of the Subdivision Agent.
D. 
Sewerage facilities. Where public sewerage facilities are available, the service shall be extended by the subdivider to all lots within a subdivision, and septic tanks will not be permitted. Every subdivision shall be provided by the subdivider with satisfactory and sanitary means of sewerage collection and disposal in accordance with the design standards and specifications for sewerage construction and improvements meeting the approval of the Subdivision Agent and the Health Official.
E. 
Private water and/or sewerage facilities. Nothing in this regulation shall prevent the installation of privately owned water and/or sewerage facilities in areas where public water and/or sewerage facilities are not available; provided, however, that such installations must meet all the requirements of the State Water Control Board, the State Health Department and any other state or local regulation having authority over such installation.
F. 
Lot size. The minimum lot size in any area shall be in accordance with Chapter 148, Zoning.
G. 
Septic tanks. The Agent shall not approve any subdivision where sanitary sewers are not provided until the Agent shall have received, in writing, from the Health Official a statement to the effect that each lot proposed in the subdivision is satisfactory for the installation of septic tanks and drainfields, as well as a 100% reserve drainfield replacement area for each drainfield, and that such approval by the Agent is only with the understanding that where septic tanks are to be installed, these must be approved on an individual lot basis by the Health Official.
H. 
Flood control and drainage. The subdivider shall provide, when requested, all information needed to determine what improvements are necessary to properly develop the subject property, including contour intervals, drainage plans and flood control devices. The subdivider shall also provide plans for all such improvements, together with a surveyor, or provide plans for all such improvements, together with a surveyor or engineer's statement that such improvements, when properly installed, will be adequate for proper development. The Highway Engineer shall then approve or disapprove the plans. The subdivider shall also provide any other information required by the Highway Engineer.
I. 
Fire protection. Fire hydrants in a subdivision at locations approved by the Agent shall be installed by the subdivider, provided that central or public water is available.
J. 
Easements. The Agent may require that easements for drainage through adjoining property be provided by the subdivider. All utility easements for overhead facilities shall be a minimum of 30 feet wide along all roads and a minimum of 15 feet wide along each side property line or as designated on the plat. Utility easements for underground facilities shall be a minimum of 15 feet wide along all roads and a minimum of eight feet alongside each property line or as designated on the plat. A separate ten-foot easement for all sewer force mains, including private force mains to remote drainfields, shall be required. No utility easement shall be permitted to have a slope greater than 2:1. Wherever cuts and fills adjacent to highway rights-of-way are greater than 2:1, the utility easement shall be located beyond the steep slope.
K. 
Plans and specifications. The subdivider shall submit two prints of the plans and specifications for all required physical improvements to be installed, which prints shall be prepared by a surveyor or engineer, and shall be submitted to the Agent for approval or disapproval within 45 days. If approval is granted, one copy bearing certification of such approval shall be returned to the subdivider. If disapproved, all papers shall be returned to the subdivider with the reason for disapproval in writing.
L. 
Part of a tract. Whenever part of a tract is proposed for platting and it is intended to be subdivided into additional parts in the future, a sketch plan for the entire tract shall be submitted with the preliminary plat.
In addition to the area and width requirements already specified, lots shall be arranged in order that the following considerations are satisfied:
A. 
Shape. The lot arrangement, design and shape shall be such that lots will provide satisfactory and desirable sights for buildings and be properly related to topography and conform to requirements of this chapter. Lots shall not contain peculiarly shaped elongations solely to provide access to other roads unless approved by the governing body.
B. 
Location. Each lot shall abut a street dedicated by the subdivision plat or an existing publicly dedicated street or a street which has become public by right of use. If the existing streets do not conform to the requirements of § 128-19A(4), the subdivider shall make provisions in the deeds to the lots for all buildings to be so constructed as to permit the widening by dedication of such roads or streets to the minimum requirements.
C. 
Corner lots. Corner lots shall have extra width sufficient for any required building lines on both streets as determined by the Subdivision Agent.
D. 
Side lines. Side lines of lots shall be approximately at right angles or radial to the street line.
E. 
Remnants. All remnants of lots below minimum size left over after subdividing of a tract must be added to adjacent lots or otherwise disposed of rather than allowed to remain as unusable parcels.
F. 
Separate ownership. Where the land covered by a subdivision includes two or more parcels in separate ownership, and lot arrangement is such that a property ownership line divides one or more lots, the land in each lot so divided shall be transferred by deed to single ownership simultaneously with the recording of the final plat. Said deed is to be deposited with the Clerk of the court and held with the final plat until the subdivider is ready to record the same, and they both shall then be recorded together.
Where created by the subdivision of land, all new blocks shall be of modern design and shall comply with the general requirements hereinafter set forth:
A. 
Length. Generally, the maximum length of blocks shall be 1,200 feet, and the minimum length of blocks upon which lots have frontage shall be 500 feet.
B. 
Width. Blocks shall be wide enough to allow two tiers of lots, except where fronting on major streets, unless prevented by topographical conditions or size of the property, in which case the Agent may approve a single tier of lots.
C. 
Orientation. Where a proposed subdivision will adjoin a major road, the Subdivision Agent may require that the greater dimension of the block shall front or back upon such major thoroughfare to avoid unnecessary ingress or egress.
A. 
The subdivider shall furnish a performance bond, which can be a cash bond or equivalent, letter of credit, a surety bond of a surety company or a certified check payable to the Treasurer of Northumberland County, in an amount equal to the total cost plus maintenance for a period determined by the governing body, of the improvements required in the foregoing § 128-19, so as to guarantee they will be installed within a designated reasonable length of time in a manner acceptable to the governing body and to ensure that such improvements will be properly maintained for a period determined by the governing body. Said bond or check shall accompany the final plat, as provided in § 128-10, when it is submitted to the governing body.
(1) 
In the absence of a performance bond or check, no final plat shall be approved or recorded until the required improvements have been installed and approved by the governing body or until a maintenance bond has been posted.
(2) 
Before undertaking any improvements required in the foregoing § 128-19, the subdivider shall submit four copies of his or her proposed plans and specifications to the governing body and receive written approval thereof (by the governing body or the person authorized by the governing body to approve such plans and specifications) by the return of one copy with such approval endorsed thereon. No such approval shall be given without prior written approval of the Highway Engineer and/or the Health Official, as may be appropriate. Said plans and specifications shall have been prepared by a qualified surveyor or engineer, registered by the Commonwealth of Virginia. Of the copies retained, one shall be forwarded to the Highway Engineer and one to the Health Official, when appropriate, and the remaining copy or copies to be filed with the governing body's copy of the final plat.
(3) 
The governing body or its authorized agent may make such inspections during and after final installation of the improvements required herein as shall be deemed necessary, and no installation shall be accepted as completed until approved by the governing body or its authorized agent.
B. 
Policy with respect to hard surfacing subdivision roads and the eligibility of subdivision roads to be taken into the state secondary system of highways.
(1) 
Roads must be constructed to state specifications, and all construction work, except for the bituminous surface treatment or its equivalent, must be completed to each lot within 60 days after closing of the sale of such lot. An extension of the sixty-day requirement may be granted by the Board of Supervisors in the event that the divider demonstrates that a substantial hardship exists in completing the road within 60 days. The developer shall post with the County a performance bond in an amount equal to the Department of Highway's estimate to condition and surface treat and maintain the roads are hard surfaced to state specifications and are accepted into the State Secondary System of Highways. However, when any road or portion thereof qualifies for the State Secondary System of Highways, it must be constructed and turned over to the Virginia Department of Transportation within 90 days or within such time as agreed upon by the Board of Supervisors and or authorized agent.
(2) 
If the performance bond is a cash bond, it shall be posted with the County and be deposited by the Treasurer of the County into a special savings bank account, to the end that the interest there from when added to the principal would apply to the escalation in costs of conditioning and surface treating the streets or roads.
(3) 
The eligibility of subdivision roads to be taken into the State Secondary System of Highways will be based on the requirements of the Virginia Department of Transportation standards for subdivision roads in effect from time to time; however, this will not be the final criteria. The final authority to request the Virginia Department of Transportation shall be within the sound discretion of the governing body.