The following improvements will be required
except where this chapter specifically waives the requirement or when
the Land Use Board waives the requirement by specific resolution in
conjunction with hardship, peculiar situations or special development
provisions:
|
Required For All Roads Except Local Class
II
|
Required For Local Class II
| |
|---|---|---|
|
Paved streets
|
Yes
|
Yes
|
|
Curbs and gutters
|
Yes
|
Yes
|
|
Sidewalks
|
Yes
|
No
|
|
Water mains and fire hydrants
|
If available
|
No
|
|
Sanitary waste disposal
|
Yes
|
Yes
|
|
Storm drainage
|
Yes
|
Yes
|
|
Street signs
|
Yes
|
Yes
|
|
Streetlighting
|
Yes
|
No
|
|
Street and shade trees
|
Yes
|
Yes
|
A.
Street design
standards. The following minimum standards shall be required for all
streets other than county or state roads and highways constructed
in Harmony Township:
(1)
Horizontal
alignment shall have:
|
Street Class Major Collector
(feet)
|
Minor Collector
(feet)
|
Class I & II Local
(feet)
| |
|---|---|---|---|
|
Minimum center-line radius
|
600
|
500
|
300
|
|
Minimum tangent between reverse curves
|
200
|
160
|
120
|
|
Intersection radius (curb returns)
|
40
|
30
|
25
|
|
Minimum intersection radius shall be determined
by the highest street class in the intersection, and the right-of-way
line shall be concentric thereto.
| |||
(2)
Vertical
alignment.
(a)
Vertical
alignment shall have:
[1]
Minimum
grade of five-tenths percent (0.5%).
[2]
Maximum
grade of 6% (8% on local streets).
[3]
Maximum grade for less than 200 feet may exceed Subsection A(2)(a)[2] by 2%.
[4]
Maximum
grade within 100 feet (measured from near side curbline) of an intersection
of 4%.
(b)
All changes
in grade shall be connected by vertical curves, including grade changes
at intersections.
(c)
The length
(L) in feet of a vertical curve shall be related to the algebraic
difference in the percent of grade (A) and a constant according to
the following formula:
|
L=KA
|
|---|
|
The minimum "K" values shall be as follows:
|
|
Street Class
|
Crest Curve
|
Sag Curve
|
|---|---|---|
|
Major collector
|
145
|
100
|
|
Minor collector
|
65
|
60
|
|
Local
|
28
|
35
|
|
Intersection (stop conditions) (Rounded by PC/PT
of curb returns)
|
3
|
3
|
(3)
Stopping
sight distances shall be at least:
|
[Based on height of drivers eye of 3.75 feet
above road surface. Height of object five-tenths (0.5) feet above
road surface.]
|
|
Street Class
|
Sight Distance
(feet)
|
|---|---|
|
Major collector
|
350
|
|
Minor collector
|
275
|
|
Local
|
200
|
(5)
In regulating
subdivisions, these provisions shall be considered the minimum requirements
generally consistent with the public welfare, and the Board, in consultation
with the Township Engineer, shall modify or extend these provisions
in appropriate cases as may be deemed necessary for the public good.
Modifications to these standards shall be based on A Policy On Design
of Urban Highways and Arterial Streets, latest edition, published
by the American Association of State Highway Officials, or other published
basis.
(6)
Standards
for all other roads shall be determined by the appropriate authorities.
(7)
Required
curbing and construction types for street improvements. Curbing and
construction types for street improvements shall be in accordance
with the following requirements:
(a)
Pavement construction shall conform with Chapter 410, Streets and Sidewalks, of the Harmony Township Code.
(b)
Curb construction shall conform with Chapter 410, Streets and Sidewalks, of the Harmony Township Code.
(c)
These
provisions shall be considered minimum requirements generally consistent
with the public welfare, and the Township Engineer shall modify or
extend these provisions in appropriate cases as may be deemed necessary
for the public good.
B.
General street
improvements.
(1)
Driveway
aprons.
(a)
All driveways
or other parking areas shall have driveways aprons extending from
the curbline to the front of the property line.
(b)
Driveway
aprons shall be of concrete having a thickness of six inches where
sidewalks are required or of six inches of bituminous concrete where
no sidewalks are required and shall have widths as follows:
|
Residential
|
Width Minimum
|
Maximum
(Feet)
|
|---|---|---|
|
Single driveway
|
8
|
20
|
|
Double driveway
|
16
|
20
|
|
Other uses
|
25
|
40
|
(2)
Sidewalks.
(a)
All sidewalks
shall be four inches thick and at least four feet wide, constructed
of one course of concrete, except that a sidewalk forming part of
a driveway apron shall be six inches thick at grade with abutting
sidewalks, and of the same construction material as abutting sidewalks.
(b)
All sidewalks
shall be located one foot within the street right-of-way.
(3)
Street signs.
Street signs shall be provided by the subdivider conforming to current
Township standards.
(4)
Street trees.
(a)
Street
trees shall be provided in all subdivisions.
(b)
Trees
shall be of nursery stock of an approved species, grown under the
same climatic conditions as at the location of the development. They
shall be of symmetrical growth, free of insects, pests and disease,
suitable for street use and durable under the maintenance contemplated.
(c)
The average
trunk diameter measured at a height of six feet above the finished
grade level shall be a minimum of two to three inches, depending on
good practice, with reference to the particular species to be planted.
(d)
Trees
shall be planted at intervals of from 40 to 60 feet apart (depending
upon the species) along both sides of the street and at least 1.5
feet from any sidewalk, curb, gutter or other right-of-way improvement
as provided for in this regulation, whether such improvement is proposed
to be built or not.
(e)
All planting
shall be done in conformance within street rights-of-way shall be
finish-graded, properly prepared and seeded or sodded with lawn grass
in conformance with good nursery and landscape practice.
(5)
Planting
strips. All planting strips within street rights-of-way shall be finish-graded,
properly prepared and seeded or sodded with lawn grass in conformance
with good nursery and landscape practice.
(6)
Shade trees.
(a)
Shade
trees shall be provided in all subdivisions.
(b)
Trees
shall be of nursery stock of an approved species grown under the same
climatic conditions as the location of the development. They shall
be of symmetrical growth, free of insects, pests and disease, suitable
for residential use and durable under the maintenance contemplated.
(c)
The average
trunk diameter measured at the height of six feet above finished grade
level shall be a minimum of one to two inches, depending on good practice,
with reference to the particular species to be planted.
(d)
Trees
shall be planted on each residential lot at the rate of one tree for
each 5,000 square feet of lot area or recreation space, provided that
this requirement may be reduced by the number of existing trees retained
in good condition on the lot, except that trees within tree rows along
the periphery of the lots or tract shall not be included in this determination.
A.
Sanitary sewers.
B.
Water mains and
fire hydrants.
C.
Streetlighting
shall be guided by the following minimum requirements:
|
Street Class
|
Minimum Average Maintained Footcandles
|
Uniformity
(average to minimum)
|
|---|---|---|
|
Major collector
|
0.5
|
6:1
|
|
Minor collector
|
0.3
|
___
|
|
Local
|
0.2
|
___
|
D.
Other utilities
shall be designed to meet the requirements of the operating utility
but shall be designed to be serviced for repair or additional installation
without disruption to streets.
A.
Grading and drainage
system plan.
(1)
A preliminary
grading and drainage system plan shall be a part of the preliminary
plat. It shall indicate in general terms a proposal for an adequate
system of drainage structures to carry off and store or discharge
the stormwater runoff and natural drainage water which originates
not only within the property boundaries but also that which originates
beyond the property boundaries. It should perpetuate existing drainage
patterns.
(2)
The public
improvement and utilities plan and profiles shall show the final drainage
plan, site grading and street profiles.
(3)
No stormwater
runoff or natural drainage water shall be so diverted as to overload
existing drainage systems or create flooding or the need for additional
drainage structures on other private properties or public lands without
proper and approved provisions being made for taking care of these
conditions. Watersheds with drainage areas over (1/2) square mile
come under the jurisdiction of the New Jersey Department of Environmental
Protection. Approval of this agency must be secured for any culvert
or bridge crossing falling into this category. Copies of any correspondence
with the Department of Environmental Protection shall be supplied
to the Township Engineer.
B.
Collection system.
(1)
The quantities
of water for which the collection system shall be designed shall be
in accordance with the Rational Method of design using the following
formula:
|
Q = CIA
| |
|
Where:
| |
|
"Q" is the required capacity, in
cubic feet per second, for the collection system at the point of design.
| |
|
"A" is the tributary drainage area,
in acres, and shall include areas tributary from outside sources as
well as from within the site itself.
| |
|
"C" is the coefficient of runoff
applicable to the drainage area and shall be based on consideration
of soil conditions, average slope of the drainage area and degree
of ultimate development of the area, but in no case shall be less
than the following coefficients:
|
|
Usage
|
Density
(units per acre)
|
Topography
| |||
|---|---|---|---|---|---|
|
Flat
(0-10%)
|
Rolling
(10-20%)
|
Hilly
(Over 20%)
| |||
|
Residential
| |||||
|
High density
|
4-6
|
0.50(0.40)
|
0.55(0.45)
|
0.60(0.55)
| |
|
Medium density
|
1-4
|
0.45(0.35)
|
0.50(0.40)
|
0.55(0.50)
| |
|
Low density
|
Fewer than 1
|
0.40(0.30)
|
0.45(0.35)
|
0.50(0.45)
| |
|
Impervious surfaces
|
0.90
|
0.90
|
0.90
| ||
|
Undeveloped woodland
|
0.30(0.20)
|
0.35(0.25)
|
0.50(0.45)
| ||
|
Pasture and grassed areas
|
0.30(0.20)
|
0.36(0.20)
|
0.42(0.37)
| ||
|
Cultivated fields
|
0.50(0.50)
|
0.60(0.50)
|
0.72(0.62)
| ||
|
The above runoff coefficients assume that clay
soils (sand gravel soils coefficients indicated in parenthesis) are
present and that paved areas (parking) have been provided, and any
deviation from these factors would result in an adjustment in "C"
values. Determination of nonlisted uses shall be a subject of special
study and approved by the Township Engineer.
|
|
"I" is the rainfall intensity, in inches per
hour, and shall be determined from the graph entitled "Rainfall Intensity
Duration for Essex and Union Counties," copies of which are on file
with the Township Clerk and is made a part hereof. The minimum time
of concentration shall be 10 minutes, which shall be used as the initial
Tc for all roadway drainage systems.
|
(2)
The following
intensities shall be used to determine "Q."
(3)
Pipes or
conduits shall be designed using Manning's equation for velocity:
|
V = 1.486 R 2/3 S 1/2
|
|
"R" is the hydraulic radius of the conduit flowing
full.
|
|
"n" is Manning's roughness coefficient, which
shall be as follows:
|
|
Concrete pipe
|
0.012
| |
|
Corrugated metal, 2 2/3 x 1/2 inches corrugations
| ||
|
Plain or fully coated
|
0.024
| |
|
Paved invert
|
0.020
| |
|
Fully paved
|
0.012
| |
|
3 x 1 inches corrugation
|
0.027
| |
|
6 x 2 inches corrugation (field bolted)
|
0.032
| |
|
"n" for other materials shall be as recommended
by the Township Engineer.
|
|
"S" is the slope of the energy gradient, in
feet per foot, and shall generally be considered as being the same
as the slope of the invert of the pipe (So); however, such slopes
shall be checked against the available hydraulic gradient whenever
the system flows full or where the system discharges into a body of
water.
|
(4)
Velocity.
(a)
Wherever
possible to ensure a self-cleansing velocity, pipes shall be placed
on grades that will provide a minimum velocity of three feet per second
when flowing on-fourth (1/4) full. The following table indicates minimum
grades to accomplish this:
|
Desirable Minimum Gradients for Concrete
Pipe
| |
|---|---|
|
Diameter
(inches)
|
Slope N=0.012
|
|
15 (minimum permissible)
|
.008
|
|
18
|
.006
|
|
24
|
.005
|
|
30
|
.004
|
|
36
|
.003
|
|
42
|
.002
|
|
48
|
.0016
|
|
54
|
.0014
|
|
60
|
.0012
|
|
66
|
.0011
|
(b)
Where
steep grades are encountered, full-flow velocities over 15 feet per
second should be avoided by the use of drop manholes or inlets in
the line.
(5)
Alignment.
(a)
Manholes
or inlets shall be provided in drain lines not more than 350 feet
apart and wherever branches are connected or sizes are changed and
wherever there is a change in alignment or grade.
(b)
Alignment
of pipes shall be in a straight line between manholes or inlets, except
that radius pipe may be used in pipes over 60 inches in diameter,
provided that a manhole or inlet is incorporated at not more than
five-hundred-foot intervals.
(6)
Inlet spacing
and headwalls.
(a)
Inlet
spacing shall be such as to permit a spread of water to the edge of
the traveled way, edge of shoulder for rural roads or edge or parking
lane (eight feet maximum) for urban roads during a storm with an intensity
of three inches per hour. Inlet spacing may vary up to 350 feet, depending
on the contributory drainage area and the longitudinal and cross slopes
of the roadway. Inlets at intersections shall be located to intercept
water before it crosses the intersection or crosswalk area, and inlets
shall not be placed in the crosswalk area. Pairs of inlets shall be
placed at low points.
(b)
Inlets
intercepting swales or in parking areas shall be designed such that
not more than six inches (three inches in parking areas) shall pond
over an inlet during a storm with an intensity of three inches per
hour.
(c)
Pipelines
starting or ending in ditches, streams or other bodies of water shall
terminate with either a headwall or a flared end section. Riprap or
other suitable material shall be' provided to prevent erosion.
C.
Open channel
flow. Where brooks, ditches, swales or other channel flows are used,
they shall be designed by the use of Manning's equation as indicated
for collection systems above, with the following considerations:
(1)
The friction
factor (n) shall be:
|
Unlined
| |
|---|---|
|
Earth, uniform section
|
0.018-0.027
|
|
Earth, nonuniform section
|
0.025-0.040
|
|
Earth, not maintained
|
0.080-0.012
|
|
Lined
| ||
|---|---|---|
|
Concrete
| ||
|
Finished
|
0.015
| |
|
Rough
|
0.25
| |
|
Riprap
|
0.35
| |
(2)
Design velocities
should be limited to a nonerosive velocity and shall be determined
based on an analysis of the soil conditions, but in any case shall
not exceed the following;
|
Materials
|
Velocity
(feet per second)
|
|---|---|
|
Fine sand to fine loam
|
2.5 to 3.5
|
|
Stiff clay to hardpan
|
3.75 to 6.00
|
|
Concrete-lined ditch
|
15
|
|
Velocities shall be controlled by use of check
dams or baffles where necessary.
| |
(3)
A ditch or
brook right-of-way of sufficient minimum width to include a ten-foot
access strip in addition to the width of the ditch or brook from bank
top to bank top shall be offered for dedication to the Township for
drainage purposes. Such right-of-way shall be shown on the drainage
plan and on the final plat.
(4)
Swales shall
be provided in residential areas so that an area not in excess of
the minimum lot area in the subdivision shall drain without being
intercepted. This requirement may be varied for wooded sites or pervious
soils.
(5)
Swales shall
be provided in other areas so that not less ban one impervious acre
shall drain without being intercepted.
(6)
Jute mesh
slope protection shall be used in swales or grassed ditches. Paved
ditches shall be used where the velocity exceeds the erosive velocity.
(7)
Side slopes
for a drainageway shall be as follows:
|
Facility
|
Maximum Side Slope
|
|---|---|
|
Channel
|
2:1
|
|
Ditch
|
4:1
|
|
Swale
|
6:1
|
D.
Minimum cover
and structural considerations.
(1)
All pipe
shall be concrete, unless specific unique design considerations exist
for the use of other types of materials and then only with the approval
of the Township Engineer.
(2)
Minimum cover
for reinforced concrete pipe shall be based upon a depth of cover
of two feet from top of pavement to top of pipe.
(3)
Minimum cover
for corrugated metal pipe shall be based upon a depth of cover of
one foot from top of pipe to top of pavement or upon manufacturer's
recommendations, whichever is greater.
(4)
Maximum cover
for pipe shall be based on rational analysis through use of Marston's
formula. For reference, see the booklet "Reinforced Concrete Pipe
Culverts," issued by the United States Department of Commerce, and
manufacturer's recommendations for flexible pipe.
(5)
Standard
strength reinforced concrete pipe shall conform to Class 3, Wall B,
and extra strength reinforced concrete pipe shall conform to Class
4, Wall B, of ASTM Specifications C-76 of AASHO Designation M-170.
Strengths for corrugated metal pipe shall be as required by the New
Jersey State Highway Department Standard Specifications, current edition
and amendments.
(6)
Box culverts
shall be designed in accordance with AASHO recommendations.
E.
Design criteria
not covered herein.
(1)
Criteria
not incorporated herein necessary for design shall be based on recommendations
incorporated with Hydraulic Engineering Series circulars published
by the Federal Highway Administration and ASCE Publication. "Design
and Construction of Sanitary and Storm Sewers," current edition, and
as approved by the Township Engineer.
(2)
Design methods
prepared by the Soil Conservation Service may be used for drainage
design with the approval of the Township Engineer.
All work shall be done in conformance with the
current construction standards of the Township of Harmony, or in lieu
thereof, the current edition of the New Jersey State Highway Department
Standard Specifications for Road and Bridge Construction, 1961, with
amendments and revisions thereto, and with the New Jersey Department
of Transportation standard construction details.
