A.
Before final approval is granted for any subdivision, the developer
shall submit a complete set of plat construction detail sheets and
specifications to the City Engineer for evaluation. The details on
each sheet shall be numbered or lettered. Once approved by the City
Engineer, the developer shall not alter or vary the construction documents
without prior consultation with the City Engineer.
[Amended 5-24-2016]
B.
As a minimum, the plat construction detail sheets and specifications
shall incorporate the requirements of this chapter.
[Amended 1-24-2012]
A.
All utilities shall be installed on or before the completion of the
roadway base course. Work shall be constructed with the deepest utility
being installed first and working up to the road surface. The Community
Services Department shall be notified 72 hours prior to the start
of any construction. All subsurface work shall be visually inspected
by the City Engineer or designee prior to backfilling.
B.
These inspections shall be completed during normal working hours
within a twenty-four-hour period after notification. Covering work
before it has been inspected shall be sufficient cause for rejection.
Final testing of subsurface utilities for acceptance by the City shall
be completed prior to paving the road surface. All testing and inspections
shall be at the expense of the developer. Material samples and/or
product certification sheets shall be supplied to the City Engineer
or designee upon reasonable notice.
Utility and street improvements shall be provided by the subdivider
in accordance with the standards and requirements described hereinafter.
The standards contained hereinafter shall be considered as minimum
requirements, and nothing contained herein shall be construed to imply
that the subdivider cannot construct or provide improvements of a
higher quality.
A.
The developer shall provide permanent reference monuments along the
side of street rights-of-way and reference pins along the side of
any easement.
B.
Monument specifications.
(1)
Permanent monuments shall be of stone or reinforced concrete four
inches by four inches by 48 inches, with a drill hole in the center,
set in such a manner so that they will not be disengaged by frost;
if of concrete, the mix shall be Class A.
[Amended 7-27-2021]
(2)
All reference pins shall be of ferrous metal, 1/2 inch in diameter
or larger and a minimum of 24 inches in length. The pin may be solid,
hollow, round, square or any other standard configuration normally
used by surveyors. The pin shall be driven into the ground and shall
not protrude above the ground surface more than 1 1/2 inches.
[Amended 9-8-1987; 1-24-2012]
A.
General. In general, all new streets within the subdivision and all
work to be undertaken thereon shall be designed and constructed according
to the specifications adopted by the New Hampshire Department of Transportation.
All plans for such improvements shall be submitted for approval or
approval with modifications to the City Engineer.
B.
Grading roadway and side slopes. The roadway and side slopes thereof
shall be considered as part of a site's improvements and, as such,
shall be constructed substantially in accordance with the street cross-sectional
design standards. Side slopes shall not exceed one foot vertical rise
per every two feet of horizontal length without retaining structure
or other special considerations. If the depth of fill is over five
feet, the contractor may be required to perform certain operations
to ensure that major settlement will occur prior to continuing construction.
C.
All backfill in trenches and fill for roadbeds shall be thoroughly
compacted to 95% of optimum density, unless otherwise specified in
the approval specifications. All compaction is subject to testing
by the City Engineer or designee.
D.
Street construction standards. All streets within the jurisdictional
authority of the City, with the exception of state highways, shall
be improved in accordance with the following minimum criteria and
shall further be arranged and constructed in accordance with the provisions
set forth hereinafter:
(1)
Base course.
(a)
The depth of the base course shall be as shown on the standard
road cross section.
(b)
Base course shall not be constructed during freezing weather
or on a wet or frozen subgrade. Blading and rolling shall be required
to provide a smooth, even and uniformly compacted course true to cross
section and grade. A minimum slope of the finished base course shall
be 1/2 inch per foot or as may be required on curves or on superelevations.
(c)
Any portion of the base course material which is not accessible
to means of proper compaction with rolling equipment shall be compacted
thoroughly by methods satisfactory to the Community Services Department.
All yielding or unstable material shall be excavated as directed and
brought up to grade with satisfactory material.
(d)
At all times during construction, the subgrade and all ditches
shall be constructed and maintained so that the roadbed will be effectively
drained to prevent erosion.
(e)
The top four inches of the base course shall not contain stones
over three inches in diameter. The gravel pit shall be acceptable
to the City.
(f)
In areas with excessive clay, water or loam base, the depth
of the base course shall be more than the minimum depth. The base
course depth and required base drainage shall then be properly designed
by the subdivision engineer and approved by the City Engineer (e.g.,
by increasing base depth as needed or road underdrains, or both).
(g)
Design depth shall be based on current engineering practices,
using percolation results obtained during the wet season, soil-bearing
capacity and type.
(h)
Samples of all gravel materials and gradation analysis to be
used in project shall be submitted to the City Engineer's office upon
request.
(2)
Street paving.
(a)
Street paving shall be accomplished by placing a minimum of
four inches in two courses of hot asphalt concrete for streets that
are to become public streets. The minimum thickness of each course
shall be as shown on the standard cross section which shall be placed
with a self-propelled mechanical spreader and compacted with a minimum
ten-ton tandem roller. Paving shall be allowed between April 15 and
November 15 only and shall not be placed unless the atmospheric temperature
in the shade is above 40° F. and the mixture delivered to the
spreader has a temperature above 250° F. Pavement shall not be
placed on wet or frozen roadbeds. Unless otherwise specified, paving
regulations shall be the same as those specified in the State of New
Hampshire Department of Transportation Standard Specifications for
Road and Bridge Construction, adopted and approved, latest edition.
In special instances, when it has been determined that there is an
emergency situation, the above requirements may be waived by the Community
Services Director. The Planning Board shall be notified of any waivers
by the Director of Planning and Community Development.
(b)
The hot-asphalt concrete shall consist of the following materials:
the aggregate shall be as indicated in New Hampshire Department of
Transportation specifications; bituminous material shall be an asphalt
cement AC 85-20100, unless otherwise designated on the plans ordered;
and the percentage of bituminous material shall be determined at the
plant site to ensure proper control. This is in no way to relieve
the contractor from designing a road pavement for a higher classification
of traffic which would require a heavy pavement for strength or a
different design mix as approved by the Community Services Department.
(c)
The subdivider shall be required to improve arterial and collector
streets only to the width required by the current and immediate needs
of his subdivision, consistent with the standards and specifications
herein contained.
(d)
Alleys, where permitted or required, shall have not less than
a four-inch bituminous concrete surface and a sixteen-inch base course
as required for streets.
E.
Where a subdivision will create a public roadway, a sign shall be
erected on the site alerting those traveling the roadway that they
are on a roadway that is not accepted or maintained by the City of
Dover and they travel at their own risk. Said signage shall be located
and approved by the City Engineer or Director of Planning and Community
Development prior to land disturbance.
[Amended 8-26-2008; 1-24-2012]
All areas of a subdivision shall be graded to prevent ponding of water or eroding of property. In addition to the installation of curbs or gutters along the streets as required by § 157-46, storm sewers or other drainage appurtenances shall be constructed throughout the entire subdivision to carry off water from all inlets and catch basins and be connected to an adequate outfall. The stormwater drainage system shall be separate and independent of the sanitary sewer system and shall be in accordance with drainage laws of the State of New Hampshire. Included in the overall design shall be any work necessary in order to provide adequate and satisfactory drainage along the side of any existing street which is adjacent to the subdivision. The plans and specifications for the disposing of stormwater and the construction thereof shall be approved by the City Engineer. Manholes will be required upon request, to be located between catch basins.
A.
Design.
[Amended 5-24-2016]
(1)
Proper sizing of culverts, pipes, etc., shall be by acceptable established
engineering practice.
(3)
A sample set of the calculations used in sizing the various pipes
and a list of the variables used must be submitted to the City Engineer's
office. Failure to include this information could result in a delay
of the review process.
B.
Standards of construction.
(1)
All improvements shall meet the specifications of the American Association
of State Highway and Transportation Officials (AASHTO) in regards
to material and strength requirements.
(2)
Catch basins or drop inlets shall be equal to New Hampshire Standard
Type A with three-foot sumps or four-foot sumps with hoods, if required
by the City Engineer.
(3)
Minimum size pipe shall be 12 inches in diameter for storm drains.
Minimum size culvert shall be 15 inches in diameter.
(4)
All pipes shall be one of the following:
[Amended 5-24-2016]
Typical Use
|
RCP
|
HDPE
|
PVC
|
---|---|---|---|
Culverts
|
X
|
X
|
—
|
Storm drains
|
X
|
X
|
X
|
Drive culverts
|
X
|
X
|
—
|
Underdrain (6-inch)
|
—
|
X
|
X
|
NOTES:
| ||
X
|
=
|
Acceptable
|
RCP
|
=
|
Reinforced concrete pipe (Class III minimum)
|
PVC
|
=
|
Polyvinyl SDR 35 pipe
|
HDPE
|
=
|
High-density polyethylene
|
(5)
There shall be a three-foot minimum cover over all pipes.
(6)
Culvert headwalls/endwalls, when required, shall be either concrete
or mortar rubble masonry.
(7)
Erosion protection of ditches or pipe outlets shall be provided where
soil and/or velocity conditions warrant protection by paving or use
of stone.
(8)
No stormwater pipe, catch basin, drainage inlet or other pipes (floor
drains) used to drain surface water shall be connected to any sanitary
sewer system.
[Amended 1-24-2012]
A.
Each lot in the subdivision shall be provided at the property line
with a connection to the public sanitary sewer system. This connection
shall be shown with tie-in distances on the as-built plans. The construction
of the sewer system shall conform to the approved plans and specifications,
and all work must be properly inspected and approved by the City Engineer
or representative. In general, the design of municipal sewer lines
shall follow the guidelines presented in the Water Pollution Control
Federation Manual of Practice No. 9.
B.
In the case of a private wastewater disposal system, both a City
and a state permit are required. The system must be designed in accordance
with New Hampshire Department of Environmental Services requirements
and must be approved and inspected by the City and state. Backfilling
before either party has made the inspection will constitute grounds
for rejection. Such approval notwithstanding, the Planning Board,
on the advice of a sanitary system engineer of its own choice, may
approve or disapprove or approve with modifications such plans if
it deems such state-approved plans insufficient and may make additional
requirements. In no case will discharge of pollutants into surface
water or wetlands be permitted, nor will any system which utilizes
mechanical or powered devices be permitted unless a copy of a service
contract, prepaid at least 12 months in advance, giving the City or
any citizen thereof the power to call for repairs, or a bond in lieu
thereof, shall be submitted to the Planning Board, and after approval,
such contract shall be renewed annually. It shall be understood that
failure to renew and/or nonrepaired failure of such sewage system
shall be grounds for eviction of residents, whether owners or tenants,
unless and until the system is rendered functional.
[Amended 1-14-2020]
C.
An adequate sanitary sewer shall be designed by a qualified registered
engineer to handle all of the present and future development incorporated
in a subdivision. A manhole shall be installed at each change of alignment
in the pipe and/or beginning or end, as well as each change of grade,
but at intervals not to exceed 300 feet. Manhole frames and covers
shall be of heavy-duty type. Manholes shall be precast and watertight.
D.
Any sewer lift station required for a subdivision shall be designed
by a qualified registered engineer as to its capacity and type. Final
approval of the type of station shall be specified by the Community
Services Department. All manuals pertaining to said lift station (i.e.,
operation, service guaranty) shall be turned over to the City. All
lift stations shall be duplex, pump-type installations unless specifically
approved otherwise. The decision to accept any sewer lift station
is entirely a City option and shall be based on the recommendations
of the City Engineer, Community Services Director and the Dover Utilities
Commission to the Planning Board. The owner of a private system shall
maintain a service contract (contact information to be provided to
the City) with a licensed service provider to perform the required
maintenance. The service contract shall provide for an annual report
to the City Engineer detailing the condition of the system, and maintenance
report.
E.
All pipes shall be sized and have proper bearing material under them.
All trenches shall be opened by the developer for inspection by the
Community Services Department prior to approval. House connections
shall be made in a workmanlike manner, and tees shall be supplied
in the main. Should a tap be required, it shall be completed by use
of a mechanical tapping machine. All joints shall be tight-fitting
and sealed. Inspections shall be completed on a normal workday within
a forty-eight-hour period after notification. Lateral connections
shall be through a tee (wye) or cast-iron saddle. All joints of said
sewer system shall be cemented or consist of a suitable locking-type
joint to prevent the seepage of water either in or out. Minimum slope
of a sanitary sewer shall be established to maintain a minimum average
velocity of two feet per second.
F.
Materials selected for sewer construction shall be of the following
types:
G.
Construction standards shall be clearly emphasized in the specifications,
and attention shall be directed to the bedding material and backfill
requirements. Suitable compaction as required by the City Engineer
shall be provided. All sewer lines laid at a grade less than 0.01
shall be set with a laser. All lateral connections which use sewer
saddles shall be tapped with a mechanical tapping machine and suitably
sealed. All manholes shall be made watertight with brick inverts.
All joints between pipes and with manholes shall be cemented or consist
of an adequate locking-type joint to prevent water seepage in or out
of the system.
[Amended 9-8-1987; 1-24-2012]
A.
All subdivisions in the City of Dover shall provide municipal water
service when available or required by the Planning Board. Installation
of all water mains is subject to the approval of the Community Services
Department.
[Amended 1-14-2020]
B.
When City water is supplied, each lot shall have a separate connection
brought to the lot line, equipped with an outside stop and capped
until ready for use. All house service lines shall be connected to
the main by the use of tapped couplings. The developer shall provide
ties for the end of the service and the outside stop to the City Engineer's
office for each lot in the development.
C.
When City water is available and/or required, the system shall be
designed by a qualified registered engineer. Each system shall be
designed to handle the expected flows, domestic and fire, for present
and future development within the subdivision.
D.
In general, the design of City water mains shall follow the guidelines
prescribed by the American Waterworks Association (AWWA). In addition,
thrust blocks shall be supplied as necessary and gate valves shall
be provided on all sides of junctions with other mains. All waterlines
shall be installed with a minimum of five feet of cover. The minimum
size of a water main shall be eight inches in diameter. The water
main shall be sized to provide adequate fire flow to the proposed
development and any future development. The design size must be approved
by the City Engineer.
E.
Materials selected for water construction shall be American-made,
meet American Waterworks Association standards and shall meet the
following minimum requirements:
(1)
Pipe and fittings. All pipe shall be cement-lined ductile iron pipe,
Class 52. All fittings shall be ductile iron. All fittings and pipe
shall be American Waterworks Association standard Class 140, coal-tar
dipped or greater. All valve boxes shall be ductile iron and of the
sliding type, tar-coated, both inside and out. All gate valves shall
be Mueller or Clow and must open counterclockwise.
(2)
Hydrants. All hydrants shall be Eddy manufacture and subject to the
following additional details. All hydrants shall be of iron body.
All hydrants shall be the improved type with breakable flanges, painted
red body with silver reflective domes and nozzles. All hydrants shall
open counterclockwise, with the direction of opening cast on the head
of the hydrant. All hydrants shall have a valve opening of 5 1/4
inches, hose nozzles conforming to the national standard of nozzles
and 2 1/2 inches and steamer nozzle 4 1/4 inches. Hydrants
shall be long enough to accommodate a minimum bury of 5 1/2 feet
and equipped with six-inch pipe connections. All hydrants shall be
plugged.
F.
Construction standards shall be clearly emphasized in the specifications.
Attention should be directed to bedding and backfill requirements.
Various gates and other fittings shall be installed in conformance
with manufacturer's specifications. Hydrants shall be installed not
less than one foot nor more than three feet from the curb and so installed
that the center of the hydrant steamer nozzle shall be at least 18
inches above the finish grade. All hydrant gate valves shall be installed
with anchoring tees to the water main with the top of the box flush
with finish grade.
G.
The Director of Community Services shall be notified at least 48 hours prior to any construction involving water mains. All new pipes shall be inspected as provided by § 157-37. Tests to be performed shall include but not be limited to water sampling and testing for contamination.
[Amended 1-14-2020]
[Amended 1-24-2012; 7-27-2021]
All regulatory signs shall be installed in conformance with
the Manual on Uniform Traffic Control Devices. A permanent street
marker shall be placed at each intersection designating the names
of the streets entering said intersection and shall comply with the
specifications as provided by the City. All street signs shall be
of the approved size, color and type set forth by the Community Services
Department and shall be purchased at a nominal rate from the Department
or other suitable source of supply. The signs shall be installed at
the expense of the developer and done to the satisfaction of the Community
Services Department. If a roadway is to remain private, a private
sign marker shall be added to the street sign.
[Amended 1-24-2012; 12-18-2012]
For subdivisions that include the construction of a new road,
all utility lines for telephone and electric service shall be placed
underground in the right-of-way or in rear lot easements. Where telephone
and electric service lines are placed underground entirely throughout
a subdivided area, said conduits or cables shall be placed within
easements or dedicated public ways in a manner which will not conflict
with other underground services. They shall be a minimum of five feet
from any other utility. Wherever possible, underground services will
be placed under grassed areas rather than paved areas. Further, all
transformer boxes shall be located so as not to be unsightly or hazardous
to the public. Additionally, all streetlighting fixtures and poles
shall be approved by the Community Services Director or designee.
The most energy-efficient streetlighting shall be installed.
[Amended 8-11-1992; 11-28-1995; 12-18-2012]
A sidewalk is required on at least one side of a street in the
urban core and may be required by the Planning Board on both sides
of the street where it is deemed appropriate. Sidewalks shall be of
bituminous concrete or portland cement concrete. Bituminous concrete
shall not be less than 2 1/2 inches in thickness and placed over
a six-inch gravel base. Portland cement concrete sidewalks shall not
be less than four inches in thickness, reinforced by eight-by-eight,
six-by-six wire mesh and placed on a suitable base not less than 12
inches thick. Portland cement concrete sidewalks that cross driveways
shall be not less than six inches thick and meet all the standards
listed above. All sidewalks shall be five feet in width and constructed
adjacent to the property line within the street right-of-way. Sidewalks
shall be designed to be free from obstruction; all streetlights, street
trees, mailboxes, newspaper bins, trash receptacles, or any other
type of obstruction shall be placed in the grass area between the
sidewalk and the curb.
[Amended 8-11-1992; 11-28-1995]
A.
All new and improved streets within the urban core shall be provided
with granite curbs. When the curb forms one edge of a sidewalk, the
granite curbing shall be vertical and five inches by 17 inches. Curbs
used to define driveway entrances shall be tapered as per standard
road cross section graphic.
B.
Granite slope edge curb shall be installed as specified in Section
609 of the State of New Hampshire Standard Specifications for Road
and Bridge Construction, minimum cross section of stone to be four
inches by 12 inches.
[Amended 3-23-2010]
A.
Private roads shall be designed and constructed pursuant to the following
criteria:
3 and 4 Parcels
|
5 or More Parcels in R-12, R-20, R-40, RM-SU, RM-U or
Nonresidential Districts
| |
---|---|---|
Right-of-way width (feet)
|
30
|
50
|
Road width (feet)
|
16
|
24 to 32*
|
Base course
|
12 inches bank-run gravel (A)
|
12 inches bank-run gravel (A)
6 inches crushed gravel (B)
1 1/2 inch binder and inch topcoat (C)
3-foot gravel shoulder (D) (A road profile shall be submitted
with subdivision applications. Said profile shall be rendered by a
qualified registered engineer.)
|
NOTES:
| |
*
|
The width of the roadway shall be determined by the site's physical
characteristics and the layout and density of the proposed development.
|
D.
The physical constraints of a specific tract shall dictate the Board's
consideration thereon.
Changes in the terms and specifications contained in Planning
Board approval of the improvement aspects of a subdivision application
may be required in the event subsequent excavations reveal subsurface
conditions which require special attention, e.g., underground water
requiring side drains, etc. All such changes must be approved by the
City Engineer, Director of Planning and Community Development and
the Community Services Director.
[Amended 1-14-2003; 8-26-2008]
A.
The developer shall be responsible for submitting an as-built drawing
of the project to the City Engineer's office. The drawings shall include
all items as required in the final plan with as-built locations, dimensions
and sizes. Also included on the as-built drawings shall be water and
sewer locations, depths and ties. The as-built drawings shall be submitted
in Mylar and digital formats and shall be tied into the City's GIS
coordinate system.
B.
If a street is to become a public roadway, prior to the City Engineer
processing the request and advising the City Council on whether to
accept street or not, the developer shall be responsible for submitting
a recordable deed and any associated fees to the City Engineer's office.
Once the City Council has accepted the street, the developer shall
be notified, and the City Engineer shall record the deed with the
Strafford County Registry of Deeds within 10 days of acceptance. Upon
registration, a signed, original copy of the deed shall be filed with
the City Clerk's office and a copy submitted to the developer.
[Added 5-8-2018]
A.
The provisions of this section apply to the construction, reconstruction, alteration, surfacing or resurfacing of any driveway which intersects with the right-of-way of any City-owned, City-maintained way and/or other private way. Section 125-8 of the City Code, referring to permit requirements, applies to all paving contractors or related construction enterprises engaged in the retailing of driveway paving services to the general public within Dover's City limits.
[Amended 1-14-2020]
B.
It shall be unlawful to construct, reconstruct, alter, surface or
resurface any driveway in a manner which affects the size, elevation
or grade of such driveway until the Community Services Director has
reviewed and approved of such construction or alteration and has issued
a written permit for such work. No permit shall be required for any
existing driveway, entrance or approach unless the grade, elevation,
location or width of said driveway is changed. For purposes of this
section, any driveway so constructed, reconstructed, altered, surfaced
or resurfaced as indicated above which abuts or is clearly designed
to provide access to a public way as defined by RSA 259:125 shall
be presumed to be situated within the right-of-way.
(1)
Pursuant to this section, a written construction permit application
must be obtained from and filed with the Community Services Department
by any landowner or by his/her paving contractor, if he/she is employing
one, affected by the provisions of this section.
(2)
Before any construction or alteration work is commenced, said permit
application shall have been reviewed and approved and a construction
permit issued by the Community Services Director. Said permit shall:
(a)
Describe the location, area and width of the driveway, as well
as the entrance, exit or approach. The location shall be selected
to most adequately protect the safety of the traveling public.
(b)
Describe any drainage structures, traffic control devices and
channelization islands to be installed by the applicant.
(c)
Establish grades that adequately protect and promote street
drainage and permit a safe and controlled approach to the street in
all seasons of the year.
(d)
Include any other terms and specifications necessary for the
safety of the traveling public.
C.
The following construction standards must be adhered to for driveways:
(1)
Unless an all-season sight distance of 400 feet in both directions
along the street can be obtained, the Community Services Director
shall not permit more than one access to a single parcel of land,
and this access shall be at that location determined to be safest.
The Community Services Director shall not give final approval for
use of any additional access until it has been demonstrated that the
400-foot, all-season sight distance has been approved.
(2)
Within 20 feet of the point where the driveway intersects the public
right-of-way, the maximum slope of a driveway to four or fewer dwelling
units shall not exceed 12% and the maximum slope for other driveways
shall not exceed 8%.
(3)
With the exception of shared driveways, no driveway, including any
flare, shall be within five feet of a side property line.
(4)
The angle of the driveway with respect to the pavement edge shall
not be less than 60° to 90°, except that a smaller angle may
be used for entrance driveways along a divided street, permitting
only one-way operation of the driveway.
(5)
At rural intersections, the minimum distance between the nearest
edge of the driveway and the crossroad edge of pavement, measured
along the edge of pavement, shall be 100 feet. At urban intersections,
this minimum distance may be reduced to 25 feet. Driveways to be located
on the opposite side of T-intersections shall generally conform to
the urban intersection standard. The Community Services Director shall
have the authority to increase these distances if, in his/her opinion,
such action is necessary for the protection of traffic. The distances
may also be modified if justifiable on the basis of specific site
conditions, including lot size.
(6)
The type of construction where the driveway meets the edge of the
traveled way shall be commensurate with existing conditions with respect
to drainage and curb configuration and shall be subject to the approval
of the Community Services Director. The property owner shall be responsible
for the proper installation and maintenance of all drainage facilities
(driveway culvert, swale, etc.) and the driveway bed that lies between
the edge of the traveled way and the parcel's property line.
(7)
In no case shall the permitted driveway construction cause water
to stand on the pavement, shoulders or within the street right-of-way
limits. In those cases where property development increases drainage
runoff such that existing street drainage structures are insufficient
to adequately dispose of all drainage, the applicant will be required
to provide additional or larger drainage facilities to prevent any
ponding within the street right-of-way or adjacent lands thereto.
(8)
No construction permit shall allow a residential driveway entrance,
exit or approach to be constructed more than 22 feet in width.
D.
Where the Community Services Director finds that an unnecessary hardship
may result from the strict compliance with these regulations, he/she
may modify the above regulations so that substantial justice may be
achieved and the public interest secured, provided that such modifications
shall not have the effect of nullifying the intent and purpose of
this chapter.
[Amended 1-14-2020]