The SUBDIVIDER shall observe the following general requirements
and principles of land SUBDIVISION.
The PLAN shall conform with the HUDSON Master Plan, the Official Map, if and when one is adopted, Chapter
334, Zoning, and any other pertinent state or local laws or regulations.
The PLANNING BOARD may require use of a shared ACCESS road where
two or more SUBDIVISIONs are being proposed, which SUBDIVISIONs shall
be considered a single parcel of land for this specific purpose, even
though acquired by more than one conveyance or held nominally by more
than one OWNER.
All utility installations, modifications, easements and other pertinent elements of the PLAN shall conform to §
276-13 of the LAND USE REGULATIONS.
All stormwater planning and management shall comply with Chapter
290 of the LAND USE REGULATIONS. In addition:
A. LOTs shall be laid out and graded to eliminate flood or stagnant
water pools.
(1) Where a building foundation is less than one foot above finished
road grade, suitable mechanical or natural drains shall be installed,
subject to approval of the Selectmen. The type of construction and size of pipe shall be clearly
designated on the final plot plan, as approved by the BOARD.
(2) No water shall be permitted to run across a STREET on the surface,
but shall be directed into catch basins and piped underground in a
pipe of adequate size, approved by the Selectmen, in writing.
B. Where feasible, stormwater should be directed to enter the nearest
open STREAM channel.
(1) Stormwater runoff, except in areas where the LOT size is 40,000 square
feet or larger, or where it is in already existing open STREAM channels,
shall not be permitted to flow upon the surface for a longer distance
than 4,000 feet before it enters the underground system.
(2) Catch basins shall be located on both sides of the roadway in continuous
grades at intervals of not more than 400 feet at all sags in the roadway
and near the corners of the roadway at intersecting streets.
C. A STORMWATER MANAGEMENT PLAN shall be prepared including and using the following guidelines. NOTE: In preparing the STORMWATER MANAGEMENT PLAN, please refer to and comply with the requirements provided in Chapter
290, Stormwater Management and Erosion Control, of these LAND USE REGULATIONS.
(1) No STORMWATER RUNOFF in excess of rates existing prior to new construction
shall be allowed to be discharged onto a public way or into a public
drainage system unless there is sufficient capacity to handle the
additional runoff. All drainage shall be designed to achieve a zero-increase
in runoff for both peak and volume where practicable.
(2) The direction of flow of runoff through the use of arrows.
(3) The location, elevation and size of all catch basins, dry wells,
drainage ditches, swales, retention basins and storm sewers. If infiltration
systems are proposed as part of a stormwater management plan, test
pit and percolation test data in the vicinity of the proposed infiltration
system(s) must be provided.
(4) Engineering calculations used to determine drainage requirements
shall be based upon minimum storm frequency design events as follows:
(a)
Ten-year storm event for closed drainage systems and local roadside
ditches.
(b)
Twenty-five-year storm event for culverts, major ditches and
swales and detention ponds.
(c)
Fifty-year storm event for bridges.
(5) Certification by a licensed professional engineer. (See RSA 310-A.)
(6) Any other specific study, calculation or investigation as requested
by the Town Engineer.
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[NOTE: Generally speaking, the stormwater drainage PLAN is probably the single most important element of the entire SITE PLAN. Yet, traditionally, it has been one of the most neglected elements. The Hudson PLANNING BOARD recognizes that only a professional engineer, licensed in accordance with RSA 310-A, can certify the adequacy of proposed drainage plans. APPLICANTs are expected to make the same recognition or to discuss this matter with the PLANNING BOARD. The PLANNING BOARD emphasizes that the criteria listed in § 289-20C(1) through (6) are minimum requirements stated for these general regulations. It is expected that the Town Engineer shall have the latitude to more precisely define the criteria once a specific proposal is before the PLANNING BOARD.]
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Before approval of a SUBDIVISION PLAN, the BOARD shall review
said PLAN for open space requirements to consist of parks, playgrounds
or permanently reserved open space. The open space shall not be unreasonable
in area and generally shall consist of 10% or less of the total area.
Open space areas shall be deeded to the TOWN OF HUDSON and shall be
so indicated on the final SUBDIVISION PLAN.
Due regard shall be shown for all natural features, such as
large trees, watercourses, scenic points, historic spots and similar
community assets which, if preserved, shall add attractiveness and
value to the SUBDIVISION.
Reserve strips of land which, in the opinion of the BOARD, show
an intent on the part of the SUBDIVIDER to control ACCESS to land
dedicated or to be dedicated to public use shall not be permitted.
Remnants of lots below usable size left over after subdividing
a large tract shall be added to adjacent lots rather than remain as
unusable parcels.