[HISTORY: Adopted by the Common Council of
the City of Kingston 7-11-2017 by L.L. No. 6-2017, approved 7-28-2017. Amendments
noted where applicable.]
As used in this chapter, the following terms shall have the
meanings indicated:
Shade tree roots are found primarily in the top 12 inches
of soil. Tiny absorbing roots, responsible for most of the tree's
intake of water and nutrients, are in the top several inches of soil
and can grow horizontally for quite a distance. Bare-root shipping
saves these roots and protects them with hydrogel. It allows the shipping
of trees for less cost, with much less weight.
Diameter of trunk six inches above the root flare.
A mixture of organic matter, as from leaves, bark, manure,
food waste, etc., that has decayed or has been digested by organisms.
It is used to improve soil structure and provide nutrients. Good compost
should be dark brown to black, the color of 70% cocoa dark chocolate.
Individual pieces in the compost, when broken apart, should be the
same color inside as outside.
The water that has passed through the surface of the permeable
paving or soil pit and has either overflowed or has been recollected
in underdrain pipes. The excess water discharges to the storm sewer
network.
Roots that circle the main stem that encircle, or will in
the future encircle, the tree as it grows larger. Girdling roots limit
root infrastructure, leading to tree instability.
The rate at which stormwater moves through (drains) a soil
or particular location.
A mixture of Portland cement, fly ash, washed gravel and
water. The water to cementitious material ratio is typically 0.35
- 0.45 to 1 (NRMCA, 2004). Permeable concrete has greater void space
than traditional concrete, allowing water to infiltrate directly through
the pavement surface to the subsurface.
Mixed soil for use in planting trees. Planting soil shall
be created from combinations of existing soil, soil loam, sand and
organic matter.
A mixture of crushed gravel, soil, and clay. The soil allows
roots to grow by transferring compactive load from stone to stone
with the soil in between remaining uncompacted. The clay content serves
to retain moisture.
Will constitute the following: International Society of Arboriculture
(ISA) certified arborist or other equivalent professional certification
or attendance at a workshop sponsored by Cornell Cooperative Extension,
New York State Department of Environmental Conservation (DEC), United
States Forest Service (USFS), or equivalent covering tree planting,
pruning, and basic tree care.
A minimum three-foot-by-three-foot existing planting pit
whose surface may be mulched or covered by a tree grate. New tree
pits will have minimum dimensions of four feet by five feet by three
feet (LxWxH).
A.
Location of trees along sidewalks. A tree shall not be planted (or
replanted) unless a minimum approvable pedestrian travel width of
four feet adjacent to the tree is available, allowing for a minimum
three-foot-by-five-foot planting pit. Trees should be spaced approximately
30 feet apart, and approximately 15 feet from any hydrant, utility
pole, light pole, or other infrastructure, whenever practicable.
B.
Tree species and sizes to be used along sidewalks. See Kingston Tree
Commission guidelines for species, size to be no greater than 2.5
inches' caliper. Recommend bare-root trees when practicable.
Trees shall be obtained from a licensed nursery and shall be in good
health, free from structural flaws and girdling roots.
C.
Repairs to sidewalks in cases of upheaval due to tree roots. In all
cases in which a sidewalk has heaved due to tree roots, prior approval
for any work shall be obtained from the City of Kingston Tree Commission
through the DPW sidewalk permitting process.
D.
Planting trees along sidewalks. Two key ways to prevent sidewalk damage, reduce maintenance requirements, and maintain tree health are: to increase available space for roots, and to encourage healthy root structure. The following requirements address these issues for the long-term benefit of Kingston's streetscapes. For additional proper tree planting specifications, go to Chapter 373, Trees, of the Code of the City of Kingston.
(1)
For placement of trees in existing tree pits or tree lawn, the following
Virginia Tech Soil Profile Rebuilding Method should be used to break
up compacted soil:
(a)
Mix in four inches of compost to a depth of two feet.
(b)
Apply four inches of topsoil and mix in to a depth of six to
eight inches; topsoil shall have a minimum of 3% organic matter.
(c)
Plant tree in a hole three times the width and 1.5 times the
depth of the roots of the tree.
(d)
Rootball shall be planted on unexcavated or tamped soil to prevent
settlement. Root flare shall be aligned with finish grade.
(2)
Percolation tests shall be performed on a minimum of 10% of tree
pits (lawns) or at least one representative planting site for a particular
project, or on any areas of questionable drainage as required by a
City Forester or Arborist or other qualified and properly trained
City representative. If the percolation rate is found to be less than
two inches per hour, soil rebuilding or special drainage such as underdrains
may be necessary, to be determined through consultation with the City
of Kingston Tree Commission.
(3)
Where tree pits are installed in heavy pedestrian traffic areas or
along sidewalk segments with reduced width, tree grates or other surfacing
over tree pits may be necessary or desirable. Any tree grate or other
surfacing material to be installed over a tree pit along a sidewalk
shall be submitted to the Kingston Tree Commission and the Superintendent
of Public Works for approval.
(a)
Tree grates shall be designed to withstand a minimum of Class
B, medium-duty loading, and shall have a minimum center opening of
18 inches by 18 inches.
(b)
Porous paving solutions such as Flexi®-Pave or an equal
alternative may be proposed in lieu of a tree grate, subject to the
approval of the Superintendent of Public Works and the Planning Department.
(c)
Site furnshings for tree protection, such as tree fences, guards,
or other barriers, must be approved by the Planning Department and
the Kingston Tree Commission prior to installation.
(4)
In locations where tree pits or a narrow tree lawn exists between
the sidewalk and the street with adjacent private green space nearby,
and an existing tree is replaced due to sidewalk damage, or a new
tree is planted concurrent with sidewalk replacement, two sidewalk
slabs, each typically four feet by five feet (to five feet by five
feet) in size, shall be removed and no less than a thirty-inch depth
of structural soil, as defined above, placed under the replaced sidewalk
slabs. Applications for variance from these standards may be submitted
for review to the City of Kingston Tree Commission in consultation
with the Superintendent of Public Works.
(a)
Where practicable, permeable concrete shall be utilized as the
sidewalk material for the replacement slabs.
(b)
Seams between bluestone slabs and nonporous concrete should
be as tight as possible and sealed against water entry in order to
discourage surface roots.
(c)
Under special circumstances, a minimum of one five-foot-by-five-foot
slab with 36 inches of underlying structural soil, as defined above,
may be approved. Any requests for such approval shall be made to the
Superintendent of Public Works.
(5)
In areas of newly constructed concrete sidewalk with existing adjacent
trees or that will have newly planted trees, permeable concrete pavement
shall be used, where practicable, for a minimum of five linear feet
in each direction from the center of the tree. Applications for variance
from this standard may be submitted for review to the City of Kingston
Tree Commission in consultation with the Superintendent of Public
Works.
(a)
Permeable concrete is a mixture of Portland cement, fly ash,
washed gravel and water. The water to cementitious material ratio
is typically 0.35 - 0.45 to 1 [National Ready-Mix Concrete Association
(NRMCA), 2004]. A fine, washed gravel, less than 13 mm in size (No.
8 or 89 stone) is added to the concrete mixture to increase the void
pace. All permeable concrete pavement is to be laid at a minimum four
inches' thickness, with 20% - 25% void structure.
[1]
All permeable concrete to be used in sidewalk applications in
the City of Kingston shall meet ASTM C1688. A design mix reviewed
and stamped by a licensed professional engineer attesting to such
shall be submitted to the Superintendent of Public Works prior to
construction.
[2]
Permeable concrete may be poured on site, or precast modular
permeable concrete such as StormcreteTM (or equal) may be used. In areas outside of the minimum five-foot
sidewalk width, modular paver systems such as PaveDrain® (or equal)
may be installed. The design mix for any permeable concrete material
to be poured on site and/or product information regarding precast
materials must be submitted to the Superintendent of Public Works
for approval prior to construction.
[3]
All permeable concrete shall be placed on a minimum thirty-inch
depth of structural soil or other free-draining material as recommended
by NYSDOT and approved by the Superintendent of Public Works.
[4]
After installation, permeable concrete shall be tested according
to ASTM C1701-09 for permeability.
(b)
All areas of new sidewalk adjacent to new or existing trees
shall, where practicable, have a minimum volume of 75 cubic feet of
planting soil and 375 cubic feet of structural soil placed as the
base at a minimum 30 inches' depth. Appeals for variance from
these depth and volume requirements may be granted by the City of
Kingston Tree Commission.
E.
Planting soil.
(1)
NYSDOT Item 610.14000011, Structural Soil Mix.
(a)
Mix by dry weight to be 80% washed two-inch stone, 20% soil.
The soil shall be clay loam containing at least 20% clay to maximize
water and nutrient holding capacity with a small amount of hydrogel
to aid uniform blending of the two materials.
(b)
Submit mix prior to installation for approval by the Department
of Public Works.
(c)
A list of vendors of the above soil type can be obtained from
the City of Kingston Department of Public Works.
(2)
Planting soil shall be created from combinations of existing soil,
soil loam, sand and organic matter. All organic matter contents shall
be determined on a dry weight basis. Final soil blend should have
a pH between 5.5 and 7.5. It is to be mixed mechanically or by hand
in the following proportions:
