The Hampton Planning Board prescribes the following rules and regulations to control the subdivision of land pursuant to Chapter
674:35-36, New Hampshire Revised Statutes Annotated, 1955, as amended. As provided in said Laws, no subdivision either public or private shall be authorized in the Town until its character and extent has been submitted and approved by the Hampton Planning Board.
The objects of the Subdivision Regulations are to:
• Provide against such scattered or premature subdivision
of land as would involve danger or injury to health, safety, or prosperity
by reason of the lack of water supply, drainage, transportation, schools,
fire protection, or other public services, or necessitate the excessive
expenditure of public funds for the supply of such services;
• Provide for the harmonious development of the municipality
and its environs;
• Require the proper arrangement and coordination of streets
within subdivisions in relation to other existing or planned streets
or with features of the official map of the municipality;
• Provide for open spaces of adequate proportions;
• Require suitably located streets of sufficient width
to accommodate existing and prospective traffic and to afford adequate
light, air, and access for firefighting apparatus and equipment to
buildings, and be coordinated so as to compose a convenient system;
• Require, in proper cases, that plats submitted to the
Planning Board for approval shall show open space or park land suitably
located for recreational or conservation purposes;
• Require that proposed parks shall be of reasonable size
for neighborhood playgrounds or other recreational or conservation
uses;
• Require that the land indicated on plats submitted to
the Planning Board shall be of such character that it can be used
for building purposes without danger to health;
• Assure conformance with local Zoning Ordinances and provide
such additional areas as may be needed for each lot for on-site sanitary
facilities; and
• Include provisions which will tend to create conditions
favorable to health, safety, convenience or prosperity.
For the purpose of these regulations, certain words used herein
are defined as follows:
ABUTTER
Means any person whose property is located in New Hampshire
and adjoins or is directly across the street or stream from the land
under consideration. For purpose of receiving testimony only, and
not for purpose of notification, the term abutter shall include any
person who is able to demonstrate that his land will be directly affected
by the proposal under consideration. For purposes of receipt of notification,
in the case of an abutting property being under a condominium or other
collective form of ownership, the term abutter means the officers
of the collective or association, as defined in RSA 356-B:3, XXIII.
For purposes of receipt of notification, in the case of an abutting
property being under a manufactured housing park form of ownership
as defined in RSA 205-A:1, II, the term abutter includes the manufactured
housing park owner and the tenants who own manufactured housing which
adjoins or is directly across the street or stream from the land under
consideration.
[Amended 3-21-2007]
BOARD
Means the Planning Board of the Town of Hampton.
COMPLETED APPLICATION
Means a final subdivision plat and application form submitted
with all other information and materials required by the Board to
enable it to proceed with consideration and to make an informed decision.
CONDITIONAL APPROVAL
Means approval of a subdivision plan application by a majority
of the Board, with conditions that must be met prior to and/or after
final approval.
DOUBLE FRONTAGE LOT
Means a lot that fronts upon two parallel streets or that
fronts upon two streets that do not intersect at the boundaries of
the lot.
[Amended 9-17-1997]
DRIVEWAY, COMMERCIAL
Means a way open to vehicular ingress and egress on private
commercial or industrial property providing access to a street. This
definition shall not apply to private streets.
[Added 12-17-1997]
DRIVEWAY, RESIDENTIAL
Means a way open to vehicular ingress and egress on private
residential property providing access to a street. This definition
shall not apply to private streets.
[Amended 12-17-1997]
DRIVEWAY WIDTH
Means the narrowest width of a driveway measured perpendicular
to the driveway.
[Amended 12-17-1997]
ENGINEER
Means a person licensed in accordance with Chapter 310-A,
Section 2-27, New Hampshire Revised Statues Annotated, 1955, as amended.
FINAL APPROVAL
Means all precedent conditions have been met, and the subdivision
plan has been signed by the Chairman and recorded at the Registry
of Deeds.
IMPERVIOUS SURFACE
Means any modified surface that cannot effectively absorb
or infiltrate water.
LOW IMPACT DEVELOPMENT
Means an innovative stormwater management approach that is
modeled after nature utilizing decentralized micro-scale controls
that mimic a site's predevelopment hydrology.
PRECEDENT CONDITIONS
Means conditions placed on a subdivision plan approval by
the Board that must be met prior to final approval of the plan. These
conditions must be met prior to issuance of a building permit.
PLAT
Means the final map, drawing or chart on which the subdivider's
plan of subdivision is presented to the Board for approval, and which,
if approved, will be submitted to the Register of Deeds of Rockingham
County for recording.
PRE-APPLICATION REVIEW
Means the two optional steps, Preliminary Consultation and
Design Review that an applicant may follow prior to filing a completed
application.
[Amended 5-20-1992]
PRIVATE ROAD (OR STREETS)
Means a way open to vehicular ingress and egress established
as a separate tract for the benefit of certain, adjacent properties.
This definition shall not apply to driveways.
[Amended 12-17-1997]
RESIDENT INSPECTOR
Means the person hired to oversee and inspect the actual
construction to ensure that all work is installed in accordance with
the approved plans and specifications.
SELECTMEN
Mean the Selectmen of the Town of Hampton.
STREET
Means, relates to, and includes street, right-of-way, avenue,
road, boulevard, lane, alley, viaduct, highway, freeway, and other
ways.
SUBDIVISION
Means the division of the lot, tract, or parcel of land into
two or more lots, plats, sites, or other division of land for the
purpose, whether immediate or future, of sale, rent, lease, condominium
conveyance or building development. It includes re-subdivision and
when appropriate to the context, relates to the process of subdividing
or to the land or territory subdivided. The division of a parcel of
land held in common and subsequently divided into parts among the
several owners shall be deemed a subdivision. It further applies to
any combination of and to any subdivision of any convertible land,
convertible space, or unit.
SUBSEQUENT CONDITIONS
Means conditions placed on a subdivision plan approval by
the Board that must be met after final approval, and prior to occupancy
being granted (unless otherwise stated in the approval).
SURVEYOR
Means a person licensed in accordance with Chapter 310-A,
Sections 53 - 74, New Hampshire Revised Statutes Annotated, 1955,
as amended.
TOWN ENGINEER
Means a person or firm designated by the Town to perform
such duties as may be determined by the Town.
The following items must be submitted in order for the Board
to consider it a complete application. An applicant must submit a
waiver request as outlined in Section VIII for any information not
provided with the application.
A. Application. A properly filled out and signed application, using
the most current application form available.
B. Abutters and all parties to be notified.
1. On a separate paper, the correct names and mailing addresses of the
following individuals shall be listed:
a. Abutters as defined in RSA 672:3 and these regulations;
b. The owner(s) of record (and applicant, if different);
c. All holders of conservation, preservation or agricultural preservation
restrictions;
d. Every engineer, architect, land surveyor or soils scientist whose
professional seal appears on the plan.
2. Mailing labels, in triplicate, shall be provided. Said labels to
contain the correct names and addresses of a through d above.
[Amended 7-16-2014]
C. Fees. A check made payable to the Town of Hampton equal to the required
fees.
D. Subdivision Plan. All subdivision applications (including lot line
adjustments and condominium conversions) shall submit seven (7) copies
of the subdivision plan in the format outlined in this section. An
original mylar in permanent ink of the subdivision plan plat will
be required prior to final approval of the plat.
1. Sheet size in conformance with the requirements of the Rockingham
County Register of Deeds.
2. Scale: 1" = 100', 1" = 80', 1" = 60', 1" = 50', 1" = 40', 1" = 30',
1" = 20', or 1" = 10' as appropriate.
3. Margin of at least 1/2" outside rules border lines on three sides
and at least 2" along the left side for bindings.
4. Proposed subdivision layout and site improvements including (but
not limited to) streets, pavement, buildings, and storm drainage facilities.
5. Proposed subdivision name, plan number, date of plan and any revision
dates.
6. Current owner(s) of record (and applicant, if different), and all
abutters and all holders of conservation, preservation, or agricultural
preservation restrictions keyed to plan.
[Amended 12-17-1997]
7. Name, license number, and seal of the NH registered Land Surveyor,
plus name, seal, and address of engineer.
8. North arrow and location (locus) map.
9. Tax map and parcel numbers for the existing lot(s) and proposed lots,
as determined by the Tax Assessor.
[Amended 9-6-1995]
10. Zoning District(s) and lines.
11. Lot line and other setbacks as listed in current Zoning Ordinance.
12. Adequate space for the necessary endorsement by the proper authorities.
13. The property lines of the entire lot and divided lot including angles
or bearings of the lines, dimensions and the lot area of the entire
lot and divided lots, prepared and stamped by a registered New Hampshire
Land Surveyor.
15. All existing and proposed monuments required by these regulations
that are adjacent to and in the subdivision.
16. Title and deed references.
17. Easements and other encumbrances.
18. All variances and special exceptions granted by the Board of Adjustment
for the parcel involved and the dates granted.
[Amended 5-20-1992]
19. Name(s) of proposed street(s) as approved by the Board of Selectmen.
E. Detailed plan. A detailed plan or set of plans shall be provided
and shall include the information listed below. The detailed plan
information may be combined with the subdivision plan if it does not
clutter the plan or create a hard-to-read plan. Lot line adjustments,
which do not create additional lots or increase the development potential
of a lot, are not required to submit a detailed plan.
[Amended 3-21-2007]
1. Existing topographic contours at two-foot intervals and proposed
contours after grading. Include benchmarks and datum used.
2. Natural features such as water courses, ponds, wetlands and appropriate
setbacks, rock ledges, tree lines and other essential features.
3. FEMA Flood Insurance Rate Map (FIRM) flood zone and 100-year flood
elevation contour.
4. Location and width of existing and proposed streets and roads, with
grades, typical cross-sections, and road profiles for proposed streets.
See Appendix A - Town of Hampton Typical Cross-section.
5. Utilities on and adjacent to the tract including location, size and
invert elevation of sanitary and stormwater sewers; location and size
of water mains; location of gas mains, fire hydrants, electric and
telephone poles and streetlights. If water mains and sewer are not
on or adjacent to the tract, indicate the direction and distance to,
and the size of the nearest one of each.
6. Where the topography or other conditions are such as to make it difficult
for inclusion of any facilities mentioned above within the areas to
be dedicated to the public, the preliminary layout shall show the
boundaries of proposed permanent easements to be located over or under
private property. Such easements shall be not less than 20 feet in
width and shall have satisfactory access to existing or proposed public
ways.
7. Stormwater management plan, including location of all structural
best management practices including but not limited to catch basins,
culverts, drainage pipe, drain manholes, outlets, and subsurface treatment;
method of storage and discharge, and three (3) copies of calculations.
The calculations shall be consistent with the NH Stormwater Manual
requirements and include water quality, volume and flow, groundwater
recharge volume, peak flow control for flood control purposes, channel
protection, effective impervious cover, certification of no adverse
effects on downstream drainage facilities, design storm frequency
analysis for pre- and post-construction runoff and assessment of pre-
and post construction water quality treatment.
8. Location of existing and proposed fencing, fire hydrants, utility
locations, and streetlights. Details of the streetlights, if other
than those approved by the electric company, must be shown.
9. A landscaping plan that includes the type, extent and location of
proposed landscaping and open space areas. The plan should also indicate
any existing "natural" landscaping areas to remain.
10. The location, size and design of any proposed signs.
11. Where the layout submitted covers only a part of the subdivider's
entire holding, a sketch of the prospective future street system of
the unsubmitted part shall be furnished and the street system of the
submitted part will be considered in the light of adjustments and
connections with the street system of the part not submitted. Approval
of the submitted area does not guarantee approval of the unsubmitted
area.
12. The centerline of all streets shall be shown on the plan together
with the centerline stationing. The stationing shall show all points
of curvature and all points of tangency so that at a later date independent
engineers may accurately lay out all the highways within the subdivision
and check their work without any reference other than the recorded
plan.
13. If necessary, the provision for the extension of roads and utilities
onto adjacent properties.
14. Soil erosion and sedimentation control plan.
F. Other Items Required as Applicable. The following items shall be
submitted with the application, as applicable.
1. Location and results of test pits and location of primary and secondary
leach bed sites as required by NH DES.
2. High Intensity Soil Mapping.
3. Wetland analysis/report, stamped by a licensed NH Soils or Wetland
Scientist.
4. Any state or federal permits required.
5. Any written waiver request as outlined in these regulations.
The special requirements outlined in this section may be required
by the Board, and will be assessed on a case-by-case basis.
A. Traffic Impact Analysis.
1. Purpose.
The review of any subdivision conducted by the Board under these
regulations shall ascertain that adequate provisions have been made
by the owner or his/her authorized agent for traffic safety. To facilitate
this review, the Board may require the developer to submit a traffic
impact analysis when deemed necessary due to the size, location or
traffic-generating characteristic of the development.
Traffic Impact Analysis shall address each of the following:
a. Traffic circulation and access, including adequacy of adjacent streets
and intersection, entrances and exits, traffic flow, sight distances,
curb cuts, turning lanes, and existing or recommended traffic signalization.
b. Pedestrian safety and access.
c. Off-street parking and loading.
d. Emergency vehicle access.
2. Independent Review. The Board may retain the services of a consultant
qualified in traffic planning to review the traffic impact analysis
and to ensure that adequate provisions are made in the development
plan to reduce or eliminate those impacts. The Board may further require,
pursuant to RSA 676:4(g) that the developer reimburse the Town for
reasonable costs of this review. No plan shall be approved until such
fees, if applicable, are paid in full.
3. Guidelines for Content of a Traffic Impact Analysis.
a. Proposal.
i.
Size and type of development defined as either gross square
feet in commercial or industrial developments OR number of units in
residential or other overnight accommodation developments.
ii.
Location Map, with Proposed Driveways.
b. Traffic Data.
i.
Manual counts per peak hour data. This data must be gathered
at or near time of analysis.
ii.
Twenty-four hour machine counts (an average weekday). Machine
counts on record may be used if taken less than two years prior to
the analysis.
c. Traffic Analysis.
i.
Assumptions used (i.e., growth rates, committed improvements,
and other proposed developments).
ii.
Trip generation volumes determined using the Institute of Transportation
Engineers (ITE) "Trip Generation Manual" as amended. Refer to ITE
code numbers. Trip generation volumes not obtainable using manual
must be documented.
iii.
Required Level of Analysis:
•
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All analyses must be completed for existing conditions, existing
conditions plus 10 years (no build), opening year, and opening year
plus 10 years (build).
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•
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Analysis for each proposed driveway at its intersection with
an existing street must conform to "Transportation Research Circular
212" Intersection Capacity Analysis.
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•
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Assignment of generated traffic to surrounding road network.
Analysis of adjacent road network and intersection for roadway and
intersection capacity. (Note: For roadway capacity analysis, techniques
developed in the Highway Capacity Manual, as amended are recommended.
For intersection capacity analysis techniques developed in "Transportation
Research Circular 212" are recommended).
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d. Conclusions. Summary of improvements by location, including but not
limited to:
i.
Additional pavement widths and markings for right and left turn
lanes;
ii.
Additional traffic lanes; and
iii.
Intersection signalization.
B. Performance and Maintenance Surety.
1. The Board may accept performance surety in lieu of the subdivider's
completion of street work and other required improvements prior to
the final approval of the subdivision plat. The surety shall be in
an amount, as estimated by the applicant's engineer and as reviewed
and approved by the Department of Public Works, and in a form satisfactory
to the Board to insure the construction and installation of such improvements.
[Amended 5-20-1992]
2. The Board may accept as a surety, one of the following:
a. Certified check, bank check, or savings account passbook properly
endorsed to the Town of Hampton.
b. Irrevocable Letter of Credit written so as to be self-calling.
c. Performance bond written so as to be self-calling.
[Amended 5-20-1992]
3. A performance agreement for any improvements and for compliance with
any condition shall be submitted and is subject to review and approval
by Town Counsel as to proper legal form and enforceability. The cost
of this review shall be borne by the subdivider.
4. As improvements are completed, the surety may be reduced based on
the following schedule. Prior to release of funds, the applicant shall
submit a written request to the Planning Board that includes certification
by the engineer of work completed to date.
a. Fifty percent (50%) of any surety filed with the Board for the benefit
of the Town for satisfactory completion of the streets, drainage,
sewage and water lines, and all other facilities and improvements
shown upon said subdivision plan, may be released to the subdivider
when the following are completed and accepted:
i.
Approval of the underground utilities, including sewer and stormwater
lines;
ii.
Application of binder paving.
iii.
Installation of sedimentation measures and slope stabilization.
b. Subsequent reductions in the surety amount may be made once the following
are completed and accepted. The amount of reduction shall be based
on the original cost estimate of work, but shall not exceed 90% of
original surety amount.
i.
Completion of final paving and loaming and seeding the right-of-way;
ii.
Submittal of "as-built" plans and profile, prepared by a surveyor
and an engineer, on a reproducible wash-off-mylar, with three (3)
blueline copies, scale of 1"=50' on sheets of 22" x 34", showing all
property lines, edges of pavement, sewer laterals at the property
line and mains (with ties from permanent features) and all utilities
located by station and offset from the final base line stationing
of the sanitary sewer if present, if not, then from the center line
of the right-of-way;
iii.
Final cleanup, including removing sediment from all catch basin
sumps;
iv.
Completion of any punch list items determined by the Department
of Public Works;
v.
Installation of monumentation and submittal of certificate of
monumentation;
vi.
Installation of streetlights, street name signs, stop signs,
and/or other required traffic signs;
vii.
Submittal of a deed from the subdivider to the Town for all
rights-of-way and easements, acceptance of the deed by the Board of
Selectmen and subsequent recording of said deed(s) at the Registry
of Deeds.
c. Ten percent (10%) of the original surety amount shall be retained
as maintenance surety for one (1) year after the date of conveyance
to insure the continued proper operation and integrity of the subdivision
streets, stormwater management system, sewer and water lines, and
all other facilities and improvements. Should any improvement fail
or need repair, the Town shall be able to draw on this surety as reimbursement
of costs.
5. In situations where the developer completes the improvements prior
to final approval of the subdivision plan, a 1-year maintenance bond
as listed above will still be required.
6. The acceptance of a deed, as provided above, by the Board of Selectmen,
and subsequent recording, shall acknowledge the formal dedication
of the streets, and maintenance thereafter shall be the responsibility
of the Town.
[Amended 5-20-1992]
C. Off-Site
Improvements for New Development and Redevelopment.
[Added 10-19-2022]
1. Consistent
with NH RSA 674:21 V(j), the Planning Board may determine that improvements
to off-site public roads, drainage, water, and/or sewer infrastructure
will be necessary for the occupancy of any portion of the development
subject to subdivision and/or site plan approval. In such case, the
applicant shall be required to pay their fair share for upgrading
of the public facilities to an extent necessary to protect the public
interest.
2. For the
purposes of this section, "off-site improvements" are those improvements
necessitated by a development, but which are located outside the boundaries
of the property that is the subject of a subdivision and/or site plan
application.
3. The amount
of any such exaction for off-site improvements shall be a proportional
share of the municipal improvement costs and one that is reasonably
related to the benefits accruing to the development from the improvements
financed by the exaction. The Planning Board, in consultation with
the Department of Public Works, shall determine the necessary improvements
and the appropriate exaction fee.
4. As an
alternative to paying an exaction for off-site improvements, the developer
may elect to construct the necessary improvements, subject to bonding
and timing conditions as may be reasonably required by the Planning
Board.
5. Any exaction
imposed pursuant to this section shall be assessed at the time of
Planning Board approval of the development necessitating an off-site
improvement.
6. The Town
shall refund the balance of any exaction funds that have not been
appropriated for their dedicated purposes within six years of the
date of collection.
7. The Planning Board shall have the discretion to accept an applicant-proposed donation, in a mutually agreeable amount, as an alternative. The donation shall be utilized for the same purposes as an exaction fee, or for other transportation and/or utility-related projects, consistent with the Master Plan and/or Capital Improvement Plan. A donation would not be subject to a refund pursuant to Subsection
6 above.
All subdivision plans requiring the construction of a sanitary
sewer, drainage system or roadway will require review by the Department
of Public Works. The Board may also request review by the designated
Town engineer, at the expense of the developer, in order to see that
they comply with the Town's Master Plan, best engineering practices,
and Federal, State and Town regulations.
A pre-construction conference will be mandatory prior to the
beginning of any construction of a subdivision involving municipal
improvements. It shall be called by the developer. In attendance will
be representatives of the Public Works Department, Police and Fire
Departments, all utility companies involved, and the developer's engineer,
contractor, resident inspector, and any state and/or federal officials,
as necessary.
A. Street Design and Construction Standards. The subdivider shall observe
the following general requirements and principles of street and highway
design and construction:
1. The arrangement of streets in the subdivision shall provide for the
continuation of the principal streets in adjoining subdivision or
for their proper projection, when adjoining property is not subdivided.
Subdivision streets shall be designed so as to not create any double
frontage lots.
[Amended 9-17-1997]
2. No street or highway right-of-way shall be less than fifty (50) feet
in width and may be required to be more if a greater street width
is warranted in the opinion of the Board. All streets shall have a
paved width of at least 28 feet as outlined in Appendix A. The apportioning of the street width among roadway, sidewalks,
and possible grass strips shall be subject to the approval of the
Board.
3. All streets shown on the plan shall be constructed in accordance
with the typical cross-section in Appendix A.
[Amended 12-17-1997]
a. Permits for residential driveways more than one hundred fifty (150)
feet in length shall only be issued following recommendation by the
Hampton Fire Department and approval by the Planning Board.
b. Commercial driveways: The width shall be as recommended by the Town
of Hampton Fire Department.
c. Private roads shall be built to the same quality standards as town-accepted
roads. The width of the roadway shall be as recommended by the Town
of Hampton Fire Department.
d. Variation from the accepted standards as shown in Appendix A may
only be granted with a written waiver, as outlined in these regulations.
4. No dead-end or cul-de-sac streets shall be extended from another
dead-end or cul-de-sac street without elimination of the first circular
right-of-way.
[Amended 5-20-1992; 12-17-1997]
a. Dead-end or cul-de-sac streets shall be subject to the approval of
the Board in each case and, shall terminate with a circular right-of-way
of not less than one hundred eighteen (118') feet in diameter and
a paved diameter of not less than ninety-six (96') feet.
b. Dead-end or cul-de-sac streets shall be a minimum length of 300 feet
and a maximum length of 1200 feet, measured along the centerline stations
from the right-of-way line at the existing street to the center of
the cul-de-sac.
5. Intersecting property lines at street intersections shall be joined
by such curve as prescribed by the Board in each case.
6. Grades of all streets shall conform in general to the terrain and
shall, so far as practicable, not exceed 5% for major streets and
8% for minor streets. No street shall have a grade of less than 0.5%.
7. Whenever, in the construction of a new subdivision, pavement on an
existing Town street is disturbed due to the inclusion of any utility,
the road surface will be replaced using the following method. The
excavated ditch will be replaced with clean bank-run gravel to an
elevation of 9" (nine inches) below the finished grade; 6" (six inches)
of gravel, New Hampshire Standard Specification 304.4; 95% (ninety-five
percent compaction; a 2" (two inch) tight binder in the trench with
a 1" (one inch) overlay wearing course to the entire width of the
road.
8. A resident inspector will be required for all subdivisions requiring
the construction of a road. It shall be the responsibility of the
developer's engineer to provide the resident inspector, subject to
the approval of the Director of Public Works. It shall be the responsibility
of the resident inspector to see that the subdivision is in fact constructed
in accordance with the approved plan. The developer's engineer shall
certify, at the completion of the work, that the work has been completed
in accordance with the approved plans and specifications. All required
test results shall be submitted to the Director of Public Works. If
during construction, the resident inspector discovers any errors or
changes that will require a deviation from the approved plan, he will
notify the engineer and the Director of Public Works of same.
9. When required, street name signs, stop signs, and/or other traffic
signs shall be shown on the plan and installed by the developer.
B. Sewage and Septic System Standards.
1. When public (Town) sewer is available or within a reasonable distance to the proposed project site, the plans must show a sewerage system in all streets and connection therewith to the public sewer. The Board shall have final ruling when determining if public sewer is "within reasonable distance." New sewer lines shall comply with all of the provisions of Chapter
406, Article II, Sewer Use and Construction. In areas not serviced by the public sewer system, the Board may allow private septage sewerage disposal systems that meet the requirements of the New Hampshire Department of Environmental Services (DES). No subdivision shall be approved by the Board for either a public or private sewerage system without approval of the New Hampshire DES, as required by State regulations.
2. Any subdivision designed using a pumping station that ultimately
would be the property of the Town shall require a cost comparison
analysis showing the cost effectiveness of at least the following
three (3) alternates:
c. Common force main with privately owned pumping systems.
The cost comparison analysis shall be for a period of 20 years
into the future. The analysis shall include, but not be limited to,
all capital costs and operation and maintenance costs over the 20
years. The decision as to allowing or disallowing a pumping station
will be made by the Board based on the most cost effective alternative.
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C. Stormwater Management. A stormwater management plan will be required
for all approved subdivision plans except as exempted by vote of the
Planning Board. The design and maintenance of stormwater management
systems shall conform to the appropriate Best Management Practices
in the most recent edition of the NH Stormwater Manual. The following
standards shall apply:
[Amended 3-21-2007]
1. The USDA NRCS method TR-55 Urban Hydrology for Small Watersheds shall
be used for estimating stormwater runoff. (The Rational method is
not acceptable for storm water analysis except for static analysis
of storm drains.)
2. Low Impact Development practices, which are designed to mimic natural
hydrology by reducing impervious surfaces and stormwater runoff and
increasing groundwater recharge and pollutant removal, shall be used
to the extent practicable unless the applicant can document infeasibility
to the satisfaction of the Planning Board.
3. Stormwater runoff analysis shall include modeling of 2-year, 10-year,
25-year, 50-year and 100-year 24-hour rainfall events. The peak rate
of runoff after development shall match the existing condition runoff
for these events to the extent possible. Stormwater systems shall
be designed to accommodate developed conditions, including any roads
and potential lot coverage of structures, driveways, etc.
4. Stormwater management systems for roadways that consist primarily
of catch basins, manholes and storm drain piping shall be designed
to accommodate a 25-year 24-hour storm event. Swales, ponds, bioretention
and infiltration systems and other structures subject to erosion or
potential flooding shall be designed to be stable during a 100-year
storm event. Outlets from storm drainage systems shall be designed
to be consistent with the NH Stormwater Manual and ensure discharge
velocities do not cause erosion. The Planning Board may require energy
analysis (hydraulic grade line analysis) of storm drain systems if
deemed necessary.
5. A stormwater management plan shall be prepared for any use that will
render an area impervious for more than 15% or 10,000 square feet
of any lot.
6. The peak rate of runoff discharged from the site shall not exceed
the existing discharge rate. Existing patterns of runoff across site
boundaries shall not be changed.
7. Stormwater management for the site shall emulate the natural hydraulics
and conveyance system of the site to the extent feasible. Stormwater
discharge from the site should occur at the natural drainage points
as determined by topography and existing drainage patterns.
8. The Stormwater Management Plan for the development or redevelopment
of the site shall be designed and stamped by a New Hampshire Registered
Professional Engineer and be sized to be consistent with the NH Stormwater
Manual requirements addressing the following:
a. Water Quality Volume (WQV) - The WQV is the amount of stormwater
runoff produced during rain events that shall be treated through appropriate
BMPs. The WQV represents the volume of runoff produced from the first
one inch of rainfall falling on impervious surfaces. On average and
on an annual basis, 90% of all runoff is produced by storms that produce
one inch of rainfall or less.
b. Water Quality Flow (WQF) - represents the flow rate (expressed in
cubic feet per second) associated with the runoff produced from the
first 1 inch of rainfall and is typically used in combination with
the WQV to size of the water quality treatment practices such as rain
pre-treatment devices.
c. Groundwater Recharge Volume (GRV) - As a means of maintaining the
pre-development groundwater recharge volume from the site, the design
shall include infiltration practices that enable groundwater that
relates to the site's hydrologic soil conditions.
d. Peak Flow Control for Flood Control Purposes - Consistent with NH
DES requirements in the NH Stormwater Manual, drainage calculations
shall be conducted to show that the post-development flow rates for
all flows leaving the site do not exceed the pre-development flow
rates for 2-year, 10-year, 25-year, 50-year and 100-year, 24-hour
design storms The applicant shall also demonstrate no adverse impact
to downstream properties for proposed development within an identified
100-year floodplain.
e. Channel Protection - Post-development flow shall comply with one
of the two following criteria:
i.
If the runoff volume for a 2-year, 24-hour storm volume has
not increased over the pre-development storm volume, then the post-development
peak rate for the 2-year storm needs to be no greater than the pre-development
peak flow.
ii.
If the runoff volume for a 2-year, 24-hour storm will increase
then the post-development peak rate of flow for the 2-year, 24-hour
storm shall be controlled to less than 50 percent of the peak flow
rate of the 2-year, 24 hour storm or to the 1-year, 24-hour pre-development.
f. Effective Impervious Cover (EIC) - Calculate the effective impervious
cover and determine if project falls under the "1065" rule. If not,
confirm whether project will be required to prepare a pollutant loading
and meet water quality requirements under antidegradation requirements.
g. Certification of No Adverse Effects on Downstream Drainage Facilities
- The applicant's engineer (registered professional engineer) shall
determine and certify that any additional runoff produced from the
proposed development will not have any adverse impact or overload
any existing downstream facilities either on public or private property.
The following certification statement shall be included on the site
plan:
"I certify that any additional runoff related to the proposed
development on this site will not have any adverse effects on any
open or closed, public or private downstream drainage facilities or
natural resources, under the proposed design assumptions and considerations."
h. Design Storm Frequency - The post-development peak flow rate shall
not exceed the pre-development flow rate for the 2-year, 10-year,
25-year, 50-year and 100-year storm events for all flows leaving the
site.
9. Catch Basins - All catch basins shall be designed with a minimum
3-foot sump. Commercial sites that have the potential for oil and
gasoline spills shall have catch basins equipped with inverted hood
outlets.
10. French or trench type drains shall not be allowed for the purpose
of draining surface water from any street that will, or has the potential
to, become the property of the Town.
11. Components of a stormwater system within a proposed Town-owned right-of-way
(ROW) shall be reviewed and approved by the Department of Public Works
(DPW) or its designee. DPW shall provide comment to the Planning Board
whether components of the system within the ROW are closed or open.
Detention ponds shall not be located within the ROW.
12. Any structural stormwater BMP located outside of the proposed ROW
shall be contained on one lot. This lot must remain a buildable lot,
and shall meet all requirements for a lot as outlined in the Town's
Zoning Ordinance. If an applicant demonstrates that locating the stormwater
component or facility on one lot would not be the best solution to
comply with all of the other requirements of this section, the applicant
may request a waiver of this requirement.
13. The Planning Board may, at the applicant's expense, have the stormwater
management plans reviewed by an independent engineer designated by
the Board.
14. The Planning Board shall, at the applicant's expense, require phased
inspections of the proposed stormwater management system. The frequency
and extent of these inspections will be determined by and under the
direction of the Director of Public Works.
15. A Stormwater Management Operation and Maintenance Plan (O&M Plan)
that ensures adequate long-term operation and maintenance of stormwater
Best Management Practices (BMPs) shall be prepared for the stormwater
management system. The plan shall establish the functional, financial
and organizational mechanisms for ongoing operation and maintenance
of the stormwater management system that insures that it continues
to function as designed. The plan shall address the following:
a.
All components within land deeded to the Town for ROW shall
be the responsibility of the Town once accepted by the Town, to include
but not limited to: pipes, ditches, catch basins, shoulders, etc.
b.
Closed pipes extending out from the Town ROW may be the responsibility
of the Town once accepted by the DPW and Town and located within an
easement running to the Town for that purpose. As-constructed plans
must be provided to the Town before acceptance.
[Amended 3-21-2007]
c.
Subsurface infiltration systems and open systems, to include
but not limited to: swales, ditches, level spreaders, filter strips,
dry ponds and wet ponds, outside of the ROW shall be the sole responsibility
of and shall be maintained by the owner of the lot on which they are
located. If a system extends over more than one lot, or is on a lot
owned in common, then the applicant shall demonstrate which lot owner(s)
or what association shall be responsible for maintenance.
[Amended 3-21-2007]
d.
Stormwater management BMPs shall, at a minimum, follow the recommendations
of the New Hampshire Stormwater Manual, as amended. The Town reserves
the right to correct deficiencies in such drainage systems resulting
from improper or inadequate maintenance if, in the opinion of the
Town, there is a threat to the safety or property of the general public
from such deficiencies.
e.
The O&M Plan shall include details of the inspection and
maintenance requirements of the stormwater Best Management Practices.
The plan shall identify the party(ies) responsible for implementing
the O&M Plan once construction is complete.
f.
Annual O&M Report and Certification - The property owner
or association identified as responsible for the operation and maintenance
of the stormwater management system shall provide a report on activities
performed throughout the year and a certification that the system
continues to function as designed. The annual report and certification
shall be submitted to the Town Planner by December 31st of each year.
16. Those portions of a proposed stormwater management system not within
Town ROW but proposed to be maintained by the Town shall be located
within a drainage easement per Appendix C and shall be subject to acceptance by the Town. Privately
maintained systems that do not connect to a Town-maintained system
are not required to be the subject of an easement.
[Amended 3-21-2007]
17. Easement widths and building setbacks for detention ponds shall be
as follows:
a.
The easement area shall cover the entire pond and extend 5 feet
from the toe of the exterior slope.
b.
The easement area shall extend 5 feet from the emergency overflow.
c.
Any pond not abutting the ROW shall provide a 15-foot wide access
easement from the ROW to the pond.
d.
The pond shall be set back from proposed or existing septic
systems 75 feet, unless reduced by the State of New Hampshire, Department
of Environmental Services Subsurface Systems Bureau.
18. Easement widths and building setbacks (BSB) for pipes and channels
shall be as follows:
For Pipes
|
---|
ID (inside diameter)
|
Easement Width
|
Building Setback
|
---|
ID ≤ 36"
|
15 feet
|
5 feet from easement
10 feet from pipe
|
36" < ID ≤ 60"
|
20 feet
|
7.5 feet from easement
10 feet from pipe
|
ID > 60"
|
ID plus 10 feet either side
|
10 feet from easement
|
For Channels and Swales
|
---|
W (top width of channel)
|
Easement Width
|
Building Setback
|
---|
W ≤ 10 feet
|
20 feet
|
10 feet from top of slope
|
10 feet < W ≤ 30 feet
|
W plus 10 feet each side
|
10 feet from easement
|
W > 30 feet
|
W plus 15 feet each side
|
To be determined by Planning Board. Minimum 10 feet from top
of slope.
|
19. The Planning Board may waive the requirements of this section for
a detailed drainage analysis for subdivisions if:
a.
No road construction is proposed;
b.
In its judgment such an analysis is otherwise not required because
of the size and scope of a project; and
c.
A waiver is deemed to be in the best interest of the Town.
D. Fire Protection.
1. Hydrant locations for subdivisions, relocations or additions to existing
water mains shall be spaced so that no structure is more than 600
feet along a street front from a hydrant.
2. No hydrants which have been approved for a development shall be operative
until construction with combustible materials begins. The installation
of concrete foundations is allowed prior to hydrants being operational.
Hydrant(s) may be placed into service up to seven (7) days prior to
construction with combustible materials. Combustible materials shall
be as defined by the Town adopted BOCA Basic National Building Code.
3. The Chief of the Fire Department or his designee may require hydrants
to be operational before construction of the subdivision begins.
4. Hydrants shall be installed so that there will be not less than 18
inches from the bottom of the steamer connection to the finish grade.
5. The Fire Department will make recommendations for hydrant locations
to the Planning Board within the time specified in the written request.
When final plans are approved by the Planning Board, a copy of the
plan showing hydrant locations shall be forwarded to the Fire Department.
The Fire Department will follow-up with a letter to the Town Manager
requesting approval for the hydrant(s) installation.
E. Erosion and Sediment Control Regulations.
1. General.
For the purpose of controlling soil erosion and sedimentation
in surface waters resulting from site construction and development,
the Board may require an erosion and sediment control plan for any
subdivision it deems necessary, and a plan shall be required for any
disturbance greater than or equal to one (1) acre. For the purposes
of this requirement, "disturbance" is defined as follows: the clearing,
grading and/or excavating of land. Exclusions from this definition
include: disturbance that results from routine maintenance that is
performed to maintain the original line and grade, hydraulic capacity,
or original purpose of the site (such as ditch maintenance), or activities
that are excluded from permitting by the Clean Water Act (e.g., agricultural
and silvicultural activities).
These requirements are subject to the waiver process as outlined
in these regulations. A waiver may only be granted if:
a. No new construction and/or disturbance is proposed; or
b. If the project receives a waiver from the USEPA General Permit Discharges
from Large and Small Construction Activities.
2. Standards. The following standards shall be applied in planning for
erosion and sediment control:
a. Whenever practical, natural vegetation shall be retained, protected
or supplemented. The stripping of vegetation will be done in a manner
that minimizes soil erosion.
b. The disturbed area shall be kept to a minimum and shall be protected
from erosion during the winter months.
c. Measures shall be taken to control sediment and retain it within
the project area. To the extent possible, sediment in runoff water
shall be trapped and retained within the project area.
d. Final vegetation and permanent erosion control structures shall be
installed as soon as possible following disturbances on the site.
e. Off-site surface water shall either be diverted around, or conducted
safely through, the project area.
f. All sediment control plans shall conform to the Best Management Practices
(BMPs) described in the in the most recent edition of the Stormwater
Management and Erosion and Sediment Control Handbook for Urban and
Developing Areas in New Hampshire (the Green Book) and the Best Management
Practices for Urban Stormwater Runoff (the Little Green Book).
g. The plans shall include methods for controlling wastes such as discarded
building materials, concrete truck wash out, chemicals, litter, and
sanitary wastes. These plans shall conform to the restrictions required
by the EPA Storm Water Phase II Program.
3. Responsibility For Installation/Construction. The applicant shall
bear final responsibility for the installation and construction of
all erosion and sediment control measures required by the provisions
of this section. Where erosion and sediment control plans call for
the construction of permanent erosion or sediment control measures,
the Board may require a bond or other surety sufficient to provide
for the actual construction and installation of such improvements
within a period specified by the Board.
F. Lot Monumentation.
1. Street construction. In situations where a public road is proposed,
the subdivider shall install concrete or granite monuments at least
four feet in length and four inches in diameter with suitable drill
hole at the center point, at the beginning and end of each curve at
each street intersection on the right-of-way. The subdivider shall
further install additional concrete or granite monuments along street
lines within the subdivision such that two permanent concrete or granite
monuments, one rear and one fore, are visible from each other concrete
or granite monument within the subdivision.
2. Lot corners. In situations where monumentation does not exist, a
minimum one-inch diameter iron pipe monuments shall be set at all
lot corners in the subdivision to establish the boundary lines of
lots upon the ground with reasonable permanence. Each monument shall
be set two to six inches above the finished grade of the surrounding
property. Where appropriate, one-inch-deep drill holes may be set
in an existing stone wall or in ledge, in lieu of a required monument.
When it is impossible or impractical to set a boundary monument on
a corner, it shall be set in compliance with NH Land Surveyors Administrative
Rules.
3. Wetland buffers and boundaries.
a. Granite or concrete monuments, at least four feet in length and four
inches in diameter with suitable drill hole at the center point shall
be set along the defined edge of wetlands.
b. Conservation Commission disks, approximately 4 inches in diameter,
shall be placed along the edge of wetland buffers, conservation easements
and conservation land. In situations where Conservation Commission
disks cannot be installed, an alternate method of buffer edge demarcation
may be approved by the Board.
c. The location and placement of monumentation and markers shall be
determined by the Planning Board and made a condition of approval.
The developer shall bear the cost of installation of the monument
and disks.
4. For situations in which installation of monuments cannot comply with
paragraphs 1 & 2 of this section, a licensed land surveyor may
substitute an alternate monument as long as the monument complies
with the NH Code of Administrative Rules, Board of Licensure for Land
Surveyors Administrative Rules, LAN 503.08, as amended (authorized
by RSA 310-A:53).
5. To insure the installation of monuments required by the subdivision
plan, the subdivider shall meet the following requirements:
a. If the subdivision involves the construction of a roadway, a surety
shall be collected and held until all monumentation has been installed
and certified.
b. If the subdivision does not involve the construction of a roadway,
all monumentation shall be in place prior to final approval of the
subdivision plan.
6. Once in place, a form certifying that the monumentation has been
accurately installed shall be filed with the Planning Board by the
subdivider. The form shall contain the signature and seal of the licensed
land surveyor that certified the placement of the monumentation.
[Amended 9-6-1989; 9-5-1990]
[Amended 5-20-1992; 11-4-2020]
All subdivision proposals and proposals for other developments
governed by these Regulations having lands identified as Special Flood
Hazard Areas as shown on the current effective FEMA Flood Insurance
Rate Maps and associated Flood Insurance Study shall meet the following
requirements:
1. Subdivision proposals and proposals for other developments shall
be located and designed to assure that all public utilities and facilities,
such as sewer, gas, electrical and water systems are located and constructed
to minimize or eliminate flood damage and adequate drainage is provided
to reduce exposure to flood hazards.
2. Subdivision proposals shall include base flood elevation data.
3. In riverine situations, prior to the alteration or relocation of
a watercourse, the applicant for such authorization shall notify the
Wetlands Bureau of the New Hampshire Department of Environmental Services
and submit copies of such notification to the Board, in addition to
the copies required by RSA 482-A:3. Further, the applicant shall be
required to submit copies of said notification to those adjacent communities
as determined by the Board, including notice of all scheduled hearings
before the Wetlands Bureau.
Within the altered or relocated portion of any watercourse,
the applicant shall submit to the Board certification provided by
a registered professional engineer assuring that the flood capacity
of the watercourse can and will be maintained.
4. Where new replacement water and sewer system (including on-site systems)
are proposed in special flood hazard areas, the applicant shall provide
the Board with assurance that new and replacement sanitary sewage
systems are designed to minimize or eliminate infiltration of floodwaters
into the systems and discharges from the systems are located to avoid
impairment to them or contamination from them during flooding.
5. All necessary permits have been received from those governmental
agencies from which approval is required by Federal or State law,
including Section 404 of the Federal Water Pollution Control Act Amendments
of 1972, 33 U.S.C. § 1334.