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Proposed updates to the Illinois Urban Manual regarding Tree & Forest Ecosystem Protection.
PUBLIC NOTICE
Illinois Urban Manual (IUM)
Standard Update
U.S. Army
Corps of Engineers
Chicago District
IUM Standard NUMBERs: Tree & Forest Ecosystem Protection IUM #984, Tree Protection Augering, IUM # 991, Tree Protection, IUM # 990A (In moderately urbanized to open spaces, Tree Protection, IUM 990B ( In highly urbanized areas with existing Green and Gray Infrastructure conflicts).
COmment Period Begins: November 13, 2017
Comment Period Expires: December 13, 2017
DESCRIPTION OF STANDARD
The standards Tree & Forest Ecosystem Protection #994, Tree Protection-Augering,
#991, Tree Protection (In moderately urbanized to open spaces) # 990A, Tree Protection
(In highly urbanized areas with existing Green and Gray Infrastructure conflicts).
The associated drawings are now being updated by the IUM Technical Review Committee (TRC). The TRC is comprised of representatives of various regulatory agencies, consultants, developers, and other stakeholders. The Illinois Urban Manual is the primary technical manual for Erosion and Sediment Control in the State of Illinois, and is in the process of being updated as a result of advances in product development and associated operation and maintenance practices.
The Corps of Engineers and the IUM Technical Review Committee is requesting comments from erosion and sediment control professionals, developers, engineers, contractors, and all other interested parties on the enclosed attached standard. The comments will be reviewed by the Technical Review Committee prior to the finalization of the IUM update. The approved standard will be incorporated into the Illinois Urban Manual immediately upon approval by the IUM Steering Committee and Illinois Environmental Protection Agency.
Interested parties wishing to comment on the updated standard must do so in writing no later than December 13, 2017. It is presumed that all parties receiving this notice will wish to respond to this public notice; therefore, a lack of response will be interpreted as meaning that there is no objection to the "standard" as described.
All comments regarding the proposed standard must be submitted to the following person:
Rick McAndless
Illinois Urban Manuel Technical Review Committee Coordinator
North Cook County Soil and Water Conservation District
6640 Cosman Road
Elk Grove Village, IL 600007
Phone: (224) 875-7580
r.mcandless@northcookswcd.org
It should be noted that ALL comments received on this standard (via hard copy, or electronic) will only be accepted with the full name and address of the individual commenting.
This public notice is not a paid advertisement and is for public information only. Issuance of this notice does not imply Corps of Engineers endorsement of the standard as described.
If you have any questions regarding this public notice, please contact Kathy Chernich by telephone at (312) 846-5531, or email at kathy.g.chernich@usace.army.mil.
//ORIGINAL SIGNED//
Kathleen G. Chernich
Chief, East Section
Regulatory Branch
NOTICE TO POSTMASTERS:
It is requested that this notice be conspicuously and continuously posted until December 13, 2017.
PUBLIC NOTICE
Illinois Urban Manual (IUM)
Standard Update
U.S. ARMY
CORPS OF ENGINEERS
CHICAGO DISTRICT
IUM STANDARD NUMBERS:
Tree & Forest Ecosystem Protection IUM
#984, Tree Protection Augering, IUM # 991,
Tree Protection, IUM # 990A (In moderately
urbanized to open spaces, Tree Protection,
IUM 990B ( In highly urbanized areas with
existing Green and Gray Infrastructure
conflicts).
COMMENT PERIOD BEGINS:
COMMENT PERIOD EXPIRES:
November 13, 2017
December 13, 2017
DESCRIPTION OF STANDARD
The standards Tree & Forest Ecosystem Protection #994, Tree Protection-Augering,
#991, Tree Protection (In moderately urbanized to open spaces) # 990A, Tree Protection
(In highly urbanized areas with existing Green and Gray Infrastructure conflicts).
The associated drawings are now being updated by the IUM Technical Review Committee
(TRC). The TRC is comprised of representatives of various regulatory agencies, consultants,
developers, and other stakeholders. The Illinois Urban Manual is the primary technical manual
for Erosion and Sediment Control in the State of Illinois, and is in the process of being updated
as a result of advances in product development and associated operation and maintenance
practices.
The Corps of Engineers and the IUM Technical Review Committee is requesting comments from
erosion and sediment control professionals, developers, engineers, contractors, and all other
interested parties on the enclosed attached standard. The comments will be reviewed by the
Technical Review Committee prior to the finalization of the IUM update. The approved standard
will be incorporated into the Illinois Urban Manual immediately upon approval by the IUM
Steering Committee and Illinois Environmental Protection Agency.
-2Interested parties wishing to comment on the updated standard must do so in writing no later
than December 13, 2017. It is presumed that all parties receiving this notice will wish to
respond to this public notice; therefore, a lack of response will be interpreted as meaning that
there is no objection to the "standard" as described.
All comments regarding the proposed standard must be submitted to the following person:
Rick McAndless
Illinois Urban Manuel Technical Review Committee Coordinator
North Cook County Soil and Water Conservation District
6640 Cosman Road
Elk Grove Village, IL 600007
Phone: (224) 875-7580
r.mcandless@northcookswcd.org
It should be noted that ALL comments received on this standard (via hard copy, or
electronic) will only be accepted with the full name and address of the individual
commenting.
This public notice is not a paid advertisement and is for public information only. Issuance of this
notice does not imply Corps of Engineers endorsement of the standard as described.
If you have any questions regarding this public notice, please contact Kathy Chernich by
telephone at (312) 846-5531, or email at kathy.g.chernich@usace.army.mil.
//ORIGINAL SIGNED//
Kathleen G. Chernich
Chief, East Section
Regulatory Branch
NOTICE TO POSTMASTERS:
It is requested that this notice be conspicuously and continuously posted until December 13,
2017.
ILLINOIS URBAN MANUAL
PRACTICE STANDARD
TREE AND FOREST ECOSYSTEM PRESERVATION
(acre or sq. ft.)
CODE 984
(Source: IN Drainage Handbook)
DEFINITION
The preservation of contiguous stands
of trees from damage during
construction operations.
PURPOSE
The purpose of this practice is to
preserve contiguous forested areas and
stands of trees that have present and
future value for erosion protection,
wildlife habitat, landscape aesthetics
and other economic and environmental
benefits.
CONDITIONS WHERE PRACTICE
APPLIES
This practice applies on development
sites containing stands of trees.
CRITERIA
JULIE Before any work has begun, call
JULIE- (Joint Utility Locating Information
for Excavators) at 800-892-0123 at least
48 hours prior to any work being done.
Equivalent local authorities shall also be
contacted, where applicable.
DETERMINE THE CRITICAL FOREST
EDGE ZONE The Critical Forest Edge
Zone (CFEZ) is three foot outside the
perimeter of the dripline and/or leaf
canopy of the stand of trees to be
protected. The area within the CFEZ
shall be protected from damage during
construction operations.
WHEN TO START PRACTICE All
required protection measures shall be
installed prior to the commencement of
any site development activity and shall
remain in place and in working,
functional order until all site
development activities have ceased or
the surrounding area has been
stabilized and the site has been
inspected.
FENCING Per IUM Standard Drawing
IUM-690-A TREE PROTECTION
FENCING, trees to be protected per the
approved construction plan or by local
ordinance shall be protected with
fencing placed at the CFEZ. This area
shall be protected from damage during
construction operations.
984 - 1
Significant or historical trees to be
protected shall require chain link tree
protection fencing to be set at the CFEZ.
For projects without highly significant or
historical trees that will last for less than
a six-month duration, a non-treated
wood lath or wire-mesh fencing shall be
used and the fence securely anchored
to the posts.
For projects over a six-month duration
or trees that are considered significant
or historical trees, a chain link fence with
IUM Construction Specification 91
CHAIN LINK FENCE or better (as
approved by the local Forester per local
ordinances singularly or in tandem with
the project Engineer) shall be used.
IUM Standard Drawing IUM-690-A
TREE PROTECTION FENCING.
Fencing shall be a minimum of 4 feet in
height. For chain link fencing, metal
posts shall be placed 6 feet maximum
spacing on center (OC) and fencing
securely anchored to the posts.
from the fence 10 feet and shall be
continuous around the perimeter of the
fence. These erosion control measures
include, but are not limited to vegetative
filter strip, rolled excelsior blankets or
woodchip mulch with a minimum of 3
inches to a maximum of 5 inches deep.
Other methods may be used if approved
by the Professional Forester, Certified
Arborist or equivalent professional.
Installation shall cause no disturbance
to soils.
All foot or vehicular traffic or
construction activities shall be kept
outside of the CFEZ for the entire
duration of the construction.
As a precautionary measure, actions
shall be taken to disperse the load,
minimizing soil compaction and
mechanical root damage around the
CFEZ. These soil protection strategies
to be implemented by non-mechanical
methods such as:
No construction activities shall be
permitted within the CFEZ. In addition,
all roadways, parking areas, and
storage areas shall be located 10 feet
outside the CFEZ. Fences shall be
maintained to prevent clearing, grading
and development activities from
encroaching within the CFEZ.
Applying and maintaining 10 to
12 inches of woodchip mulch to
the area
Laying three-quarter inch
minimum thick plywood, beams,
commercial logging or road mats
over a four inch or greater layer
of woodchip mulch
SIGNAGE Notices shall be posted on
the fences prohibiting dumping and
disposal of waste near protected trees.
Signs shall be posted that identify the
fenced areas as CFEZ.
All methods and measures to be
installed shall be approved by the
Professional Forester or Certified
Arborist or equivalent.
SOIL EROSION CONCERNS Soil
erosion and sediment control measures
shall be installed outside the CFEZ to
prevent sediment from reaching the
CFEZ. Per IUM Standard Drawing IUM690-A, these measures shall extend out
Stone and woodchip mulch exceeding
four inches thick must be removed from
the CFEZ once the threat of soil or root
damage is passed. Any removal of
vegetation or spreading of woodchip
mulch materials within the CFEZ shall
984 - 2
be performed manually, and all efforts
should be made to protect the soil.
When working within the boundary of a
municipality, local authorities such as
the Urban Forester, City Arborist,
Municipal Forester, or Public
Works/Streets Department officials
should be contacted to determine locally
enforced tree protection/preservation
standards.
When utilities or other development
features necessitate underground
movement or excavation of the soil
within the CFEZ, follow criteria in IUM
Practice Standard Code 991 TREE
PROTECTION - AUGERING. There
shall be no trenching of any tree within
the protected area of the CFEZ. For
trees on the edge of the CFEZ that are
considered to be historic or significant, it
shall be required to provide additional
tree trunk protection per IUM Standard
Drawing IUM-690-C TREE TRUNK
PROTECTION.
Tree surveys should be required for all
parcels that contain mature woodlands,
groves, young woodlands or significant
trees. Tree surveys should identify the
location, size (caliper), dripline/leaf
canopy, species, and condition health
rating of all trees having a diameter at
breast height (DBH) of 12 inches or
more or as designated in the local
ordinance. Property line and hedgerow
trees should be included in the tree
survey. Required tree surveys and
inventories should be conducted by a
Professional Forester or Certified
Arborist.
NO CHANGES IN CONTOUR Special
care shall be taken to follow the natural
drainage patterns to avoid unnatural
flow to protected trees. Any changes to
topography can cause the tree to get
reduced or increased moisture over time
thus eventually killing the tree. Water
drainage patterns shall remain the
same.
Removal of topsoil around the tree is not
allowed. The original grade shall be
maintained. Any woody vegetation to be
removed around the trees to remain
shall be cut and not pulled out by
equipment to avoid root injury to the
remaining tree(s).
Note: Measures must be installed
according to a site-specific plan and in
accordance with all applicable local,
state, and federal laws and regulations.
CONSIDERATIONS
Preserving and protecting trees and
other natural plant groups often result in
more stable soil and aesthetically
pleasing development.
It is recommended that a Professional
Forester review the pre-construction
plan; supervise/inspect the on-site tree
protection operation; and review the site
for compliance during the postconstruction phase.
The CFEZ shall be shown on the plan
sheet to scale to provide a better basis
for site development evaluation.
It is recommended that a Professional
Forester, or Certified Arborist, Licensed
Landscape Architect or an agency
designee with biological, natural
resource or environmental credentials
select the trees to be preserved before
siting roads, buildings or other
structures.
If trees are to be removed, it is
recommended that a Professional
984 - 3
Forester or Certified Arborist should be
present to supervise the tree removals
to make recommendations to ensure the
dropped trees minimize damage to
protected trees.
All trees to be removed will be recorded
by stem diameter so the responsible
party can conduct natural area
mitigation by planting enough trees to
replace the trees on at least one for one
replacement schedule. A mitigation
plan for damaged trees should be
prepared in consultation with a
Professional Forester or Certified
Arborist and included with construction
plans and contract documents.
4. Frailty of resources without existing
trees
5. Potential for soil erosion with the
absence of the forest cover
6. The loss of aesthetic quality of the
site; existence of critical areas (such
as flood plains, steep slopes, and
wet lands)
7. Unique flora and fauna
8. Health and condition of the individual
trees and the forest ecosystem
9. Loss of habitat and flora and fauna
species diversity
10. Groups of trees to be saved on the
erosion control plan
11. Alteration of drainage patterns and
ground water tables.
Complete removal of all the trees on site
followed by total site compaction well
beyond the project perimeter/footprint is
not recommended since it negatively
impacts the ability of current and future
trees to grow.
For areas with mixed forest with
moderately or highly developed areas,
multiple standards may need to be
used.
For sites greater than 15 acres in size,
that are unique examples of biodiversity,
(as identified by authorized agencies/
commissions) or where the area will be
greatly impacted by the project and no
other viable option exists, a natural
resources team consisting of a Forester,
Soil Scientist, and Botanist should be
formed to determine the alternative that
least damages the resource.
Plans and specifications for tree and
forest ecosystem preservation shall be
in keeping with this standard and will
describe the requirements for applying
the practice. At a minimum include the
following items:
The following features should be
considered when developing sites in
and around wooded areas:
1. Rare and endangered species
2. Historical or archeological
significance
3. Quantity and quality of forested area
in the county or local governmental
area and the potential for forest
fragmentation
PLANS AND SPECIFICATIONS
1. Forested areas to be preserved.
2. Location and type of fencing to be
used to protect the trees.
3. Locations of construction areas,
traffic patterns and roadways,
storage areas and parking pads, and
the construction project in
relationship to the CFEZ to be
preserved.
4. Indicate verbiage on signs to be
attached to the fence and their types
and locations.
5. Identify soil sediment control
measures outside the CFEZ.
984 - 4
All plans shall include the installation,
inspection and maintenance schedules
with the responsible person clearly
identified.
IUM Standard Drawing IUM-690-A- B
TREE PROTECTION FENCING; IUM
Standard Drawing IUM-690-C TREE
TRUNK PROTECTION and IUM
Standard Drawing IUM-690-D TREE
ROOT PROTECTION FOR AUGERING
PRACTICES (Highly Urbanized Areas).
and other tree protection measures may
be used as the plan sheet.
Illinois Department of Natural Resources
Urban and Community Forestry Web
Page Technical Resources
http://www.dnr.illinois.gov/conservation/
Forestry/UrbanForestry/Pages/default.a
spx
OPERATION AND MAINTENANCE
American National Standards for Tree
Care Operations Trees, Shrubs, and
Other Woody Plant Maintenance Standard Practice (Pruning) ANSI A300
(Part 1)
On active construction sites protected
areas should be inspected at least every
7 days for compliance and any repairs
made as needed.
The protective signs and fences shall be
removed only after all construction work
has been finished, including final
grading and shaping of the site, and the
site has been inspected by a
professional forester for damages to the
trees.
Inspections shall include a listing of
trees with damage to trunks, mounding
of soil around the trunk, evidence of root
damage, and evidence of improper
pruning.
REFERENCES
Websites
International Society of Arboriculture
http://www.isaarbor.com/store/category.aspx?cid=91
USDA FS How to Prune Trees
http://na.fs.fed.us/pubs/detail.cfm?id=26
02
Morton Arboretum. 2015. Selecting
and Planting Trees. The Morton
Arboretum, Lisle, IL
http://www.mortonarb.org/treesplants/tree-and-plant-selection-0
Publications
American National Standards for
Institute, Inc. Safety Requirements for
Tree care Operations, Z133.1 most
current version.
American Association of Nurserymen,
2014. American Standards for Nursery
Stock. ANSI Z60.1. American National
Standards Institute, Inc., Washington
D.C.
Clark and Metheny, 1998. Trees and
Development: A Technical Guide to
Preservation of Trees During Land
Development. International Society of
Arboriculture, Champaign, IL
Fazio, J.R., ed., 2011. How to Save
Trees During Construction. Tree City
USA Bulletin #7. The National Arbor
Day Foundation, Nebraska City, NE
Fazio, J.R., ed., 2010. A Systematic
Approach to Building With Trees. Tree
City USA Bulletin #20. The National
Arbor Day Foundation, Nebraska City,
NE
984 - 5
Fazio, J.R., ed., 2013 How to Manage
Community Natural Areas. Tree City
USA Bulletin #27. The National Arbor
Day Foundation, Nebraska City, NE
Fazio, J.R Trenching and Tunneling
Near Trees, The National Arbor Day
Foundation, Nebraska City, NE
Gilman, Edward and Sharon Lilly. 2008.
Best Management Practices Tree
Pruning. International Society of
Arboriculture.
Gulick, Jennifer, Senior Urban Forester.
2015. Major Construction Impacts and
Methods to Minimize Damage. Davey
Resources Group.
Hightshoe. G.L.1988. Native Trees and
Shrubs and Vines for Urban and Rural
America. Van Nostrand Reinhold, New
York, NY 10003. 819 P.
Illinois Department of Natural
Resources, Division of Forest
Resources, 2015. Urban and
Community Forestry Program Tree
Planting Standards, Springfield, IL
Smiley, E. Thomas and Kelby Fite.
October 2016. Preserving Trees During
Construction Arborist News Volume 25
Number 5. International Society of
Arboriculture, Champaign, IL
Standard Specifications for Road and
bridge Construction, 2012. Illinois
Department of Transportation.
Tree Care Industry Association. 2015.
ANSI A300 Pruning Standards Part 1.
Tree Care Industry Association.
American National Standards Institute,
Inc.
Tree Care Industry Association. 2012.
ANSI A300 Construction Management
Part 5. Tree Care Industry Association.
Watson, G. and E.B. Himelick, 1997.
Principles and Practices of Planting
Trees and Shrubs. International Society
of Arboriculture, Champaign, IL
Wenger, K, 1996. The Forestry
Handbook. Society of American
Foresters, Bethesda, MD
Videos
International Society of Arboriculture.
ISA's Best Management Practices:
Managing Trees During Construction.
International Society of Arboriculture,
Champaign, IL
Root Injury and Tree Health. Illinois
Arborists, the Morton Arboretum, the
USDA Forest Service and the
International Society of Arboriculture.
Miller, Nancy, David M. Rathke and
Gary R. Johnson. 1999. Protecting
Trees form Construction Damage: A
Homeowner's Guide. University of
Minnesota Extension.
Trenching and Tunneling: A Video
Guide for Excavating Around Trees.
The Davey Resource Group. The
International Society of Arboriculture
and the Utility Arborist Association.
Morton Arboretum. 2015. Selecting
and Planting Trees. The Morton
Arboretum, Lisle, IL
Effects of Construction Damage to
Trees in Wooded Areas. Mark Timmons
and John Hartman. International Society
of Arboriculture.
Pirone's Tree Maintenance. 7th Edition
984 - 6
Avoidance of Construction Damage to
Trees on Wooded Lots. Mark Timmons
and John Hartman. University of
Kentucky Agricultural Communications.
September, 2017
urbst984.doc
984 - 7
ILLINOIS URBAN MANUAL
PRACTICE STANDARD
TREE PROTECTION - AUGERING
(each)
CODE 991
(Source: Tree City USA Bulletin No. 35)
DEFINITION
Underground construction such as utility
work by augering (tunneling) through an
individual tree's Tree Protection Critical
Root Zone (TPCRZ).
PURPOSE
The purpose of this practice is to
preserve trees with the use of augering
in place of trenching where green and
gray infrastructure conflict with
vegetation. By restricting trenching
around trees and mandating augering
around trees roots as a way to reduce
damage to and loss of individual trees
due to root severing.
It is to be applied where underground
construction involves a tree's Critical
Root Zone (CRZ) both above and below
ground.
CONDITIONS WHERE PRACTICE
APPLIES
This practice is to be applied to areas of
development that are in close proximity
with infrastructure and trees and where
these elements are in direct conflict.
CRITERIA
This standard is to be used with the IUM
Practice Standard Code 990A - TREE
PROTECTION In Moderately Urbanized
to Open Space Areas or IUM Practice
Standard Code 990B TREE
PROTECTION In Highly Urbanized
Areas with Existing Green and Gray
Infrastructure Conflicts or IUM Practice
Standard Code 984 -TREE AND
FOREST ECOSYSTEM
PRESERVATION.
LOCAL AUTHORITY When working
within the boundary of a municipality,
local authorities such as the
Professional Urban Forester, City
Arborist, Municipal Forester, contractual
Certified Arborist, Horticulturist, or
Public Works officials should be
contacted to determine locally enforced
tree augering requirements.
JULIE Before any work has begun, call
JULIE- (Joint Utility Locating Information
for Excavators) at 800-892-0123 at least
991 - 1
48 hours prior to any work being done.
Equivalent local authorities shall also be
contacted, where applicable.
DETERMINE THE TREE PROTECTION
CRITICAL ROOT ZONE Tree protection
starts with determining the Tree
Protection Critical Root Zone (TPCRZ)
or area where the majority of roots are
located and where tree protection
fencing shall be located. The TPCRZ is
located one foot outside the Critical
Root Zone (CRZ).
To determine the CRZ, one of the two
techniques shall be used. The first is by
using the definition of CRZ or two feet
outside the perimeter of the leaf canopy
or drip line of the tree to be protected
using the length of the longest branch in
feet as the radius of the circle. The
second technique is to determine CRZ
by referring to Table 1 Guidelines for
determining tree protection zone (TPZ)
radius for healthy, structurally sound
trees per the International Society of
Arboriculture (ISA) Best Practice for
Managing Trees During Construction.
This method measures the diameter (in
inches) at 4.5 feet above ground (DBH
diameter breast height) in combination
with the trees age and tolerance to
construction. See Table 2 - Species
Tolerance Ratings.
The contractor shall use whichever
method affords the greatest protection
for the tree or whichever creates the
larger CRZ area and then add an
additional one foot to create the TPCRZ.
DISTANCE FOR AUGERING Augering
shall be done at the TPCRZ or
according to the augering requirements
distance per Table 3 using the distance
and augering depth that best protects
the tree roots.
The TPCRZ area shall be protected
from damage during construction
operations using IUM Standard Drawing
IUM-690-B TREE PROTECTION
FENCING and IUM Standard Drawing
IUM-690-C - TREE PROTECTION
TRUNK PROTECTION and IUM
Standard Drawing IUM-690-D TREE
ROOT PROTECTION FOR AUGERING
PRACTICES
Per IUM Practice Standards 990A,
990B, and 984 all required tree
protection measures including fencing
and tree trunk protection, shall be
installed prior to the commencement of
any site development activity and shall
remain in working, functional order until
all site construction work has been
finished and the site inspected by a
Professional Forester for damages to
trees.
Protection measures, including fencing
and signage, shall follow criteria in IUM
Practice Standard Code 990A - TREE
PROTECTION In Moderately Urbanized
to Open Space Areas or IUM Practice
Standard Code 990B TREE
PROTECTION In Highly Urbanized
Areas with Existing Green and Gray
Infrastructure Conflicts.
Open trenching in the root zone of a tree
is prohibited except when the trenching
falls outside the TPCRZ.
Roots must not be removed from more
than one side of the tree in any given
year.
All excavation holes are to be covered in
a wet tarp or wet burlap and kept moist
for the duration of the construction
project to protect the roots from
desiccation (Roots drying out). In some
situations, it may be necessary to hand
991 - 2
dig trenches, employ water excavation
or an air spade to locate and preserve
the roots.
All trees located where there is
insufficient space to bypass the TPCRZ
must be augered. Augering activity
shall not occur on more than one side of
the tree and shall follow distance and
depth requirements in Table 3.
TABLE 3.AUGERING REQUIREMENTS
Tree
Diameter
(in.)
Depth of
Augering
(ft.)
1-4
Distance of
Augering
from Tree
Trunk each side
(ft.)
3
5-9
5
3
10-14
10
3½
15-19
12
3½
20 inches
or more
15
4
2½
ROOT CARE
The following shall be avoided:
1. Making deep cuts that sever a large
portion of the root system, depriving
the tree of water and increasing the
tree's chance of wind throw.
2. Compacting the soil within the area
not designated for augering.
3. Any other actions, (such as
depositing concrete wash which
hardens the surface area) within 10
feet of the TPCRZ.
If any roots are impacted during the
construction process they shall be
properly pruned. Consultation with a
Professional Forester or Certified
Arborist is required on all tree roots
greater than one half inches (1/2") in
diameter that are encountered in any
construction process because of future
potential liability.
The tree roots shall be cut cleanly with
an appropriate saw or pruning shear or
other tool specifically designed for
cutting wood. Axes or other such
chopping tools shall not be used.
Shovels or other tools designed for
digging shall not be used. All roots
impacted shall be properly pruned
according to the ISA pruning standard
and associated ANSI A300 standards
Part 1. The use of heavy equipment
such as a backhoe for tree root pruning
shall be prohibited.
CONSIDERATIONS
In some situations, hand digging of roots
or the use of an air spade or hydro
excavation tool is needed. In these
cases, burlap should be used to cover
up the exposed roots to help keep them
alive and from drying out.
When site soil resources have been
greatly altered, it is recommended that
soil restoration strategies be
implemented by non-mechanical
methods such as:
1. Scarifying compacted areas,
2. Adding top soil in areas of extreme
erosion,
991 - 3
3. Adding about 12 inches of well-rotted
leaf compost, and
4. Adding ground cover using
herbaceous vegetation or young
shrub vegetation. Use of native
species is encouraged.
PLANS AND SPECIFICATIONS
Plans and specifications for augering
operations shall be in keeping with this
standard and will describe the
requirements for applying the practice.
At a minimum include the following
items:
1. The individual trees to be
protected and the location of the
proposed auger tunnel.
2. The location and type of fencing
to be used to protect trees
indicating the distance for placing
the fencing around the TPCRZ.
3. Locations of roadways, storage
areas, truck clean-out areas, and
parking pads, in relationship to
the trees to be protected.
4. Types and locations of signs.
5. A mitigation plan for damaged
trees should be prepared in
consultation with a Professional
Forester or Certified Arborist and
included with the construction
plans and contract documents.
All plans shall include the installation,
inspection and maintenance schedules
with the responsible person clearly
identified.
OPERATION AND MAINTENANCE
The protective signs and fences will be
removed only after all construction work
has been finished and the site has been
inspected by a professional forester for
damages to the trees.
It is recommended that on-site
inspections be conducted during
construction. The requirements that
apply to field revisions notification and
approval process of changes to
augering type, size and location shall be
monitored to determine compliance with
augering specifications.
REFERENCES
Website
http://www2.champaign.isa-arbor.com/c
atalog/publications.html
Publications
Clark and Metheny, 1998. Trees and
Development: A Technical Guide to
Preservation of Trees During Land
Development. International Society of
Arboriculture, Champaign, IL
Fazio, J.R Trenching and Tunneling
Near Trees, The National Arbor Day
Foundation, Nebraska City, NE
Gulick, Jennifer, Senior Urban Forester.
2015. Major Construction Impacts and
Methods to Minimize Damage. Davey
Resources Group.
International Society of Arboriculture.
ISA's Best Management Practices:
Managing Trees During Construction.
International Society of Arboriculture,
Champaign, IL
Smiley, E. Thomas and Kelby Fite.
October 2016. Preserving Trees During
Construction Arborist News Volume 25
991 - 4
Number 5. International Society of
Arboriculture, Champaign, IL
Forest Service, and the International
Society of Arboriculture.
Watson, G. and E.B. Himelick, 1997.
Principles and Practices of Planting
Trees and Shrubs. International Society
of Arboriculture, Champaign, IL
Trenching and Tunneling: A Video
Guide for Excavating Around Trees.
Davey Resource Group, International
Society of Arboriculture, and the Utility
Arborist Association.
Videos
September, 2017
Root Injury and Tree Health. Illinois
Arborists, Morton Arboretum, USDA
991 - 5
urbst991.doc
Table 1. Guidelines for determining tree protection zone (TPZ) radius for healthy,
structurally sound trees per the ISA Best Management Practices: Managing Trees
During Construction.
Species
Tolerance
Relative
Tree age*
TPZ Multiplication
Factor
High
Young
Mature
Overmature
6
8
12
Medium
Young
Mature
Overmature
8
12
15
Low
Young
Mature
Overmature
12
15
18
DBH (inches) x TPZ Multiplication Factor = TPZ radius (inches)
Note: TPZ is the same as the CRZ in this standard.
*Consult with a local Professional Forester or Certified Arborist
991 - 6
TABLE 2. TREE Species Tolerance to Root Severance and Soil Compaction
TREE SPECIES
ROOT SEVERANCE Tolerance
Soil Compaction Tolerance
Basswood
Intermediate
Sensitive
Blue beech
Sensitive
Sensitive
Butternut
Sensitive
Intermediate
Paper birch
Intermediate
Sensitive
River birch
Tolerant
Tolerant
Boxelder
Tolerant
Tolerant
Ohio Buckeye
Intermediate
Intermediate
Catalpa
Intermediate
Tolerant
Kentucky Coffeetree
Intermediate
Intermediate
Eastern Cottonwood
Tolerant
Tolerant
Red-Osier Dogwood
Tolerant
Intermediate
American Elm
Tolerant
Intermediate
Slippery Elm
Tolerant
Intermediate
Hackberry
Tolerant
Intermediate
Hawthorn
Intermediate
Intermediate
Bitternut Hickory
Intermediate
Intermediate
Honeylocust
Tolerant
Intermediate
Ironwood
Sensitive
Sensitive
Black Locust
Tolerant
Sensitive
Red maple
Tolerant
Tolerant
Silver maple
Tolerant
Tolerant
Sugar Maple
Intermediate
Sensitive
Mountain ash
Tolerant
Intermediate
991 - 7
Black oak
Sensitive
Sensitive
Bur oak
Moderately Tolerant
Intermediate
Northern Pin Oak
Sensitive
Sensitive
Red Oak
Moderately Tolerant
Sensitive
Bicolor or Swamp Oak
Intermediate
Tolerant
White Oak
Sensitive
Sensitive
Wild Plum
Tolerant
Sensitive
Serviceberry
Intermediate
Sensitive
Black Walnut
Sensitive
Intermediate
Black Willow
Tolerant
Tolerant
991 - 8
ILLINOIS URBAN MANUAL
PRACTICE STANDARD
TREE PROTECTION
In Moderately Urbanized to Open Space Areas
(each)
CODE 990A
(Source: IN Drainage Handbook)
DEFINITION
ECOSYSTEM PRESERVATION for
information on preserving stands of
trees. Refer to IUM Practice Standard
Code 990B TREE PROTECTION IN
HIGHLY URBANIZED AREAS for areas
where the green and gray infrastructure
is highly intertwined.
The protection of individual trees from
damage during construction operations
in moderately urbanized or open space
areas.
PURPOSE
The purpose of this practice is to reduce
damage and loss of individual trees
during construction by implementing
pre- to post-construction tree protection
procedures.
CONDITIONS WHERE PRACTICE
APPLIES
This standard should be used when no
local ordinance exists or in tandem with
local tree protection ordinances.
This practice applies on development
sites containing individual trees and/or
adjacent offset trees that may be
affected by the onsite construction.
Refer to IUM Practice Standard Code
984 -TREE AND FOREST
CRITERIA
LOCAL AUTHORITY When working
within the boundary of a municipality,
local authorities such as the Urban
Forester, City Arborist, Municipal
Forester or Horticulturist, or Public
Works officials should be contacted to
determine locally enforced tree
protection/preservation standards.
JULIE Before any construction work has
begun, call JULIE- (Joint Utility Locating
Information for Excavators) at 800-8920123 at least 48 hours prior. Equivalent
local authorities shall also be contacted,
by the contractor.
DETERMINE THE TREE PROTECTION
CRITICAL ROOT ZONE Tree Protection
starts with determining the Tree
990A - 1
Protection Critical Root Zone (TPCRZ)
or area where the majority of roots are
located and where tree protection
fencing shall be located. The TPCRZ is
located one foot outside the Critical
Root Zone (CRZ).
wood lath snow fence or wire-mesh
fencing shall be used and securely
anchored to the posts.
To determine the CRZ, one of the
following two techniques shall be used.
The first is by using the definition of
CRZ or two feet outside the perimeter of
the leaf canopy or drip line of the tree to
be protected using the length of the
longest branch as the radius of the
circle. The second technique is to
determine the CRZ by referring to Table
1. Guidelines for determining the tree
protection zone (TPZ) radius for healthy,
structurally sound trees per the
International Society of Arboriculture
(ISA) Best Practice for Managing Trees
During Construction. This method
measures the diameter in inches at 4.5
feet above ground (DBH diameter
breast height) in combination with the
trees age and tolerance to construction.
See Table 2. for Species Tolerance
Ratings.
The contractor shall use whichever
method affords the greatest protection
for the tree or whichever creates the
larger CRZ area and then add an
additional one foot to create the TPCRZ.
FENCING Protect trees identified in the
approved construction plan or by local
ordinance with fencing using IUM
Standard Drawing IUM-690-A TREE
PROTECTION FENCING. The fencing
shall be located at the TPCRZ edge.
Protect this area from damage during
construction operations.
For projects without highly significant or
historical trees and that will last for less
than six-month duration, a non-treated
For projects lasting over a six-month
duration or for projects with trees that
are considered significant or historical,
install a chain link fence using IUM
Construction Specification 91 CHAIN
LINK FENCE or better (as approved by
the local Professional Forester per local
ordinances singularly or in tandem with
the project Engineer). Per the IUM
Standard Drawing IUM-690-A TREE
PROTECTION - FENCING, the fencing
shall be a minimum of 4 feet in height.
For chain link fencing, metal posts shall
be placed a maximum distance of 6 feet
on center (OC) and the fencing securely
anchored to the posts.
SIGNAGE Notices shall be posted on
the fences prohibiting dumping and
disposal of waste near protected trees.
Signs shall be posted that identify the
fenced areas as TPCRZ.
SOIL EROSION CONCERNS Outside
the TPCRZ, erosion and sediment
control measures shall be installed to
prevent sediment reaching the TPCRZ.
Per IUM Standard Drawing IUM-690-A,
these measures shall extend out from
the fence 10 feet and shall be
continuous around the perimeter of the
fence. These measures include, but are
not limited to vegetative filter strip, rolled
excelsior blankets and woodchip mulch
three to five inches deep. Other
methods may be used if approved by
the Professional Forester, Certified
Arborist or equivalent professional.
Installation shall cause no disturbance
to soils.
All foot or vehicular traffic or
construction activities shall be kept
990A - 2
outside of the TPCRZ for the entire
duration of the construction.
Woodchip mulch exceeding four inches
must be removed from the TPCRZ once
the threat of soil or root damage is
passed. Any removal of vegetation or
spreading of woodchip mulch materials
within the TPCRZ shall be performed
manually, and all efforts should be made
to protect the soil.
ROOT/SOIL MANAGEMENT No
construction activities, including the
placement of topsoil, shall be permitted
within the TPCRZ. Adding of woodchip
mulch shall be done manually as
specified in the contract, construction
plan or equivalent document. All
roadways, parking areas, and storage
areas, parking, maneuvering of
machinery, stockpiling of materials, or
any other construction activities shall be
located 10 feet outside any TPCRZ of
trees and plants designated to be
protected.
The contractor shall give sufficient
notice to the appropriate authorities
concerning any soil disturbance
activities that would occur adjacent to
the TPCRZ.
NO CHANGE IN CONTOUR Special
care shall be taken to follow the natural
drainage patterns to avoid unnatural
flow to protected trees. Any changes to
topography can cause the tree to
receive reduced or increased moisture
over time. Plans should consider the
implications of changes in drainage.
Changes in contour could also cause
run-off with salt or herbicides that could
kill or harm the trees and allow other
pollutants moving or settling near the
tree. Depending on tree species this
may eventually kill the tree.
Water drainage patterns should remain
the same. In drought years and
subsequent years, (depending on
ground water recharge), consideration
should be given to avoid reductions in
soil moisture and/or groundwater table
changes or increases or reductions
during and after construction.
Removal of topsoil around the tree is
prohibited. The original grade should be
maintained. Any woody vegetation to be
removed around the trees to remain
should be cut and not pulled out by
equipment to avoid root injury to the
remaining tree(s).
WHEN TO START PRACTICE All
required protection measures shall be
installed prior to the commencement of
any site development activity and shall
remain in place and in working,
functional order until all site
development activities have ceased or
the surrounding area has been
stabilized and the site has been
inspected. If at any time fencing has
been damaged, work shall be halted
and fencing replaced at Contractor's
cost. Once fencing has been replaced,
work shall commence. At no point
during site development shall protected
trees be left without fencing. The
protective signs and fences will be
removed only after all construction work
has been finished and the site inspected
by a Professional Forester, Certified
Arborist or equivalent for damages to
the trees.
TRENCHING IS PROHIBITED Creating
a trench through the tree roots within the
TPCRZ is prohibited. The alternative to
trenching is augering. See IUM Practice
Standard Code 991 TREE
PROTECTION - AUGERING.
990A - 3
BRANCH/ROOT PROTECTION AND
BRANCH/ROOT PRUNING Branches
or roots of protected trees impacted
outside the TPCRZ shall be pruned
according to the ISA Pruning Standard
and associated American National
Standards Institute (ANSI) A300
Standards. Sufficient advance
notification of trenching activities needs
to be given to the inspectors of the root
pruning. All root pruning shall be done
under the supervision of a Professional
Forester or an ISA Certified Arborist.
Pruning should meet or exceed ANSI
A300 or approved ISA Tree Care
Industry Standards. The appropriate
pruning tool should be used to make a
clean cut. The use of heavy equipment
such as a backhoe for tree root pruning
shall be prohibited. Axes, shovels, back
hoes or other such potential severing
devises not specifically engineered for
tree root pruning shall not be used.
Removal or breaking off branches of the
protected trees will not be allowed.
Certified Arborist in charge. The root
pruned trees shall be noted on the plans
by the Professional Forester or Certified
Arborist.
All tree roots impacted during
construction shall be properly pruned.
All tree roots greater than one half
inches (1/2") in diameter that are
encountered in any construction process
shall be cut cleanly with an appropriate
saw or pruning shear or other tool
specifically designed for cutting wood as
defined by ISA and ANSI standards.
All measures must be installed
according to a site-specific plan and in
accordance with all applicable local,
state, and federal laws and regulations.
In situations where roots, extending
outside the TPCRZ, are impacted or
need root pruning or special tree care is
required, all root pruning and associated
tree care shall be done by a
Professional Forester or Certified
Arborist per industry standards. In
these situations, root pruning, using an
approved mechanical root pruning saw,
shall be performed prior to digging as
directed by the Professional Forester or
Refer to Table 2." Tree Species
Tolerance to Root Severance and Soil
Compaction."
SEEK PROFESSIONAL ADVISEMENT
On construction sites where green and
gray infrastructure are highly
intertwined, use IUM Practice Standard
Code 990B TREE PROTECTION In
Highly Urbanized Areas With Existing
Green and Gray Infrastructure Conflicts
in consultation with a local Professional
Forester or Certified Arborist concerning
species tolerance to disturbance.
REMOVALS Trees not identified to be
protected per local ordinance or
construction plans may be removed per
the advisement of the local Professional
Forester or Certified Arborist in charge.
CONSIDERATIONS
Consideration should be given to post
construction protection of trees that
were designated as "protected trees"
during the construction activities. One
example is to create a Conservancy
Easement to preserve the trees that
were protected during construction
activities.
For highly significant trees consider
increasing the Tree Protection
Critical Root Zone (TPCRZ) to 2 to 3
times to further minimize impact to
tree roots. Also consider protecting the
990A - 4
tree trunk using IUM Standard Drawing
IUM-690-C TREE TRUNK
PROTECTION. Operations of the
equipment should not break the plane of
the fencing regardless of the type of tree
trunk protection installed.
9. Impact on property value and
aesthetic,
A Professional Forester or Certified
Arborist should be consulted for any
clearing of trees and any actions that
deviate from criteria within this standard.
On-site supervision is recommended.
11. Ability to moderate temperature
changes, provide shade and reduce
wind forces,
10. Ability to screen noise and visual
improprieties or ability to enhance
privacy,
The dripline/leaf canopy shall be shown
on the plan sheet to scale to provide a
better basis for site development
evaluation.
12. Per local ordinance and consultation
with the local Professional Forester
and/or Certified Arborist, determine if
the tree(s) within the project area
has historic, big, unique or protected
designation.
Consider the following when evaluating
trees to be saved:
Trees to be removed should be
evaluated using the following criteria:
1. In the opinion of the Professional
Forester or Certified Arborist,
there is a clear and reasonable
risk of failure that could cause
injury or property damage
including existing utility service
and no corrective measures are
feasible.
1. Species and condition (maintain a
diversity of moderate to slower
growing trees in good condition),
2. Above the minimum inches of tree
diameter as designated by local
ordinance,
3. Long-term suitability of the tree for its
present location,
4. Length of time to mitigate losses,
2. Tree is dead.
3. The tree is in poor condition with
several dead branches or major
crack(s).
5. Cost of mitigating tree losses,
6. Expected long-term maintenance
costs for the tree compared to other
trees of the same age/size,
4. Contiguous and fatal disease is
present as diagnosed by a
trained Entomologist, Plant
Pathologist or Professional
Forester.
7. Soil erosion prevention and
reduction of storm water runoff,
5. The tree is below the minimum
inches in diameter as designated
by local ordinance.
8. The number of other trees growing
under the same conditions and the
precedent that would be set by
removing the tree in question,
6. Current tree damage is beyond
repair or the tree is in extremely
990A - 5
poor shape due to storm damage
or previous mechanical injury.
7. There is a potential of the tree to
damage existing or future
hardscape features such as
driveways or sidewalks and there
is no gray infrastructure
alternative.
8. There is no feasible way to avoid
disturbing the soil around,
grading over or placing a
hardened surface within the
TPCRZ and the tree is an oak,
hickory, red bud, horse chestnut,
Kentucky coffee tree, larch,
honey locust, or conifer and after
consultation with a Professional
Forester there is agreement that
the tree would not survive the
impact of the disturbance.
Consultation is required prior to
using these criteria for tree
removal.
13. Trees that are non-native species
or invasive.
A mitigation plan for damaged trees and
removed trees should be prepared in
consultation with a Professional
Forester or Certified Arborist and
included with construction plans and
contract documents. A one for one tree
replacement policy or greater should be
implemented.
When site soil resources have been
greatly altered, it is recommended a soil
restoration strategy be implemented by
non-mechanical methods such as:
1. Scarifying compacted areas,
2. Adding top soil to the original grade
in areas of extreme erosion.
3. Adding about 12 inches of well-rotted
leaf compost,
9. Tree has a greater than 45degree lean toward traffic or
another target or it creates an
unsafe clearance or visual
barrier/sight line for pedestrians
or vehicular traffic.
4. Adding ground cover using
herbaceous vegetation, shrubs, and
trees. Use of native species is
encouraged.
10. Tree is a fast growing or a weak
wooded tree that is invasive such
as box elder, silver maple, tree of
heaven, Russian olive or black
cherry. Exceptions may be made
for large healthy specimens of
these species.
11. Tree is within five feet of a
structure or, when mature, will
have a canopy spread that will
overlap the structure. Consult
with a Professional Forester or
Certified Arborist.
12. The tree could be successfully
transplanted with a tree spade.
5. When trees are to be within 25 feet
of gray infrastructure, consider using
pervious paving materials or
installing aeration vents in
impervious paving. Use paving
materials requiring a minimum
amount of excavation such as
reinforced concrete vs. asphalt.
Design traffic patterns to avoid heavy
loads adjacent to trees. Specify
minimum subgrade compaction
under pavement near dripline.
For areas with mixed forest with
990A - 6
moderately or highly developed areas,
multiple standards may need to be
used.
protection on the plan.
8. Identify soil sedimentation and
protection for outside the TPCRZ.
PLANS AND SPECIFICATIONS
Plans and specifications for tree
protection shall be in keeping with this
standard and will describe the
requirements for applying the practice.
At a minimum include the following
items:
9. Include the installation, inspection,
and maintenance schedules with the
responsible party identified in all
plans.
1. Identify all existing trees by species,
location, diameter in inches (at 4 ½
feet above the ground) and
condition. Clearly indicate the trees
and/or branches to be removed and
those to be saved including their
TPCRZ. Pruning shall be done by a
Professional Forester or Certified
Arborist.
11. IUM Standard Drawing IUM-690-A
TREE PROTECTION - FENCING
and other Tree Protection Standards
(Tree Trunk Protection and
Auguring) may be used as detailing
on the plan sheets.
2. Contact JULIE during the planning
and design stages so that utilities
and their placement near trees can
be accurately placed on the plans.
The protective signs and fences can be
removed only after all construction work
has been finished, which includes a final
grading, shaping and stabilization of the
site, and a site inspection by a
Professional Forester for damages to
the trees.
10. Fees for non-compliance per local
ordinance should be noted.
OPERATION AND MAINTENANCE
3. Identify locations of roadways,
storage areas, truck clean-out areas
and parking pads, in relationship to
the trees to be protected.
4. Determine the TPCRZ and draw it to
scale on the plan sheet.
5. Identify location, type and height of
fencing to be used to protect trees,
including the distance for placing the
fencing around the TPCRZ.
6. Provide signage details including
verbiage to be used, type of
materials for signs and location of
signage on fencing.
On active construction sites, it is
recommended that trees be inspected
every 7 days for compliance.
Inspections shall include a listing of
trees with:
1. Damage to trunks,
2. Damage to branches,
3. Mounding of soil around the trunk,
7. Designate the TPCRZ and trunk
990A - 7
4. Evidence of root damage,
American National Standards for
Institute, Inc. Safety Requirements for
Tree Care Operations, Z133.1 most
current version.
5. Evidence of improper pruning,
6. Notice of unauthorized changes to
the topography, including trenching
mishaps and or augering location
revisions, and
American Association of Nurserymen,
2014. American Standards for Nursery
Stock. American National Standards
Institute, Inc., Washington D.C.
7. Other infractions to the site around
the trees such as chemical spills and
soil compaction.
REFERENCES
Fazio, J.R., ed., 2011. How to Save
Trees During Construction. Tree City
USA Bulletin #7. The National Arbor
Day Foundation, Nebraska City, NE
Websites
International Society of Arboriculture
http://www.isaarbor.com/store/category.aspx?cid=91
USDA FS How to Prune Trees
http://na.fs.fed.us/pubs/detail.cfm?id=26
02
Illinois Department of Natural Resources
Urban and Community Forestry
Website Technical References et. al.
https://wwwdnr.partner.illinois.gov/Cons
ervation/Forestry/UrbanForestry/Pages/
TRTreeProtectionMeasures.aspx
Morton Arboretum. 2015. Selecting
and Planting Trees. The Morton
Arboretum, Lisle, IL
http://www.mortonarb.org/treesplants/tree-and-plant-selection-0
Publications
American National Standards for Tree
Care Operations Trees, Shrubs, and
Other Woody Plant Maintenance Standard Practice (Pruning) ANSI A300
(Part 1)
Clark and Metheny, 1998. Trees and
Development: A Technical Guide to
Preservation of Trees During Land
Development. International Society of
Arboriculture, Champaign, IL
Fazio, J.R., 2010. A Systematic
Approach to Building With Trees. Tree
City USA Bulletin #20. National Arbor
Day Foundation, Nebraska City, NE
Fazio, J.R., ed., 2013. How to Manage
Community Natural Areas. Tree City
USA Bulletin #27. The National Arbor
Day Foundation, Nebraska City, NE
Fazio, J.R Trenching and Tunneling
Near Trees, The National Arbor Day
Foundation, Nebraska City, NE
Gilman, Edward and Sharon Lilly. 2008.
Best Management Practices Tree
Pruning. International Society of
Arboriculture.
Gulick, Jennifer, Senior Urban Forester.
2015. Major Construction Impacts and
Methods to Minimize Damage. Davey
Resources Group.
Hightshoe. G.L.1988. Native Trees and
Shrubs and Vines for Urban and Rural
990A - 8
America. Van Nostrand Reinhold, New
York, NY 10003. 819 P.
Illinois Department of Natural
Resources, Division of Forest
Resources, 2015. Urban and
Community Forestry Program Tree
Planting Standards, Springfield, IL
International Society of Arboriculture.
ISA's Best Management Practices:
Managing Trees During Construction.
International Society of Arboriculture,
Champaign, IL
Miller, Nancy, David M. Rathke and
Gary R. Johnson. 1999. Protecting
Trees from Construction Damage: A
Homeowner's Guide. University of
Minnesota Extension.
Morton Arboretum. 2015. Selecting
and Planting Trees. The Morton
Arboretum, Lisle, IL
th
Pirone's Tree Maintenance. 7 Edition
Smiley, E. Thomas and Kelby Fite.
October 2016. Preserving Trees During
Construction Arborist News Volume 25
Number 5. International Society of
Arboriculture, Champaign, IL
Tree Care Industry Association. 2015.
ANSI A300 Pruning Standards Part 1.
Tree Care Industry Association.
Tree Care Industry Association. 2012.
ANSI A300 Construction Management
Part 5. Tree Care Industry Association.
Watson, G. and E.B. Himelick, 1997.
Principles and Practices of Planting
Trees and Shrubs. International Society
of Arboriculture, Champaign, IL
Wenger, K, 1996. The Forestry
Handbook. Society of American
Foresters, Bethesda, MD
Videos
Root Injury and Tree Health. Illinois
Arborists, the Morton Arboretum, the
USDA Forest Service and the
International Society of Arboriculture.
Trenching and Tunneling: A Video
Guide for Excavating Around Trees.
The Davey Resource Group. The
International Society of Arboriculture
and the Utility Arborist Association.
September, 2017
urbst990A.doc
Standard Specifications for Road and
Bridge Construction. 2012. Illinois
Department of Natural Resources.
990A - 9
Table 1. Guidelines for determining tree protection zone (TPZ) radius for healthy,
structurally sound trees per the ISA Best Management Practices: Managing Trees
During Construction.
Species
Tolerance
Relative
Tree age*
TPZ Multiplication
Factor
High
Young
Mature
Overmature
6
8
12
Medium
Young
Mature
Overmature
8
12
15
Low
Young
Mature
Overmature
12
15
18
DBH (inches) x TPZ Multiplication Factor = TPZ radius (inches)
Note: TPZ is the same as the CRZ in this standard.
·
Consult with a local Professional Forester or Certified Arborist
990A - 10
TABLE 2. Tree Species Tolerance to Root Severance and Soil Compaction
TREE SPECIES
ROOT SEVERANCE Tolerance
Soil Compaction Tolerance
Basswood
Intermediate
Sensitive
Blue beech
Sensitive
Sensitive
Butternut
Sensitive
Intermediate
Paper birch
Intermediate
Sensitive
River birch
Tolerant
Tolerant
Boxelder
Tolerant
Tolerant
Ohio Buckeye
Intermediate
Intermediate
Catalpa
Intermediate
Tolerant
Kentucky Coffeetree
Intermediate
Intermediate
Eastern Cottonwood
Tolerant
Tolerant
Red-Osier Dogwood
Tolerant
Intermediate
American Elm
Tolerant
Intermediate
Slippery Elm
Tolerant
Intermediate
Hackberry
Tolerant
Intermediate
Hawthorn
Intermediate
Intermediate
Bitternut Hickory
Intermediate
Intermediate
Honeylocust
Tolerant
Intermediate
Ironwood
Sensitive
Sensitive
Black Locust
Tolerant
Sensitive
Red maple
Tolerant
Tolerant
Silver maple
Tolerant
Tolerant
Sugar Maple
Intermediate
Sensitive
Mountain ash
Tolerant
Intermediate
990A - 11
Black oak
Sensitive
Sensitive
Bur oak
Moderately Tolerant
Intermediate
Northern Pin Oak
Sensitive
Sensitive
Red Oak
Moderately Tolerant
Sensitive
Bicolor or Swamp Oak
Intermediate
Tolerant
White Oak
Sensitive
Sensitive
Wild Plum
Tolerant
Sensitive
Serviceberry
Intermediate
Sensitive
Black Walnut
Sensitive
Intermediate
Black Willow
Tolerant
Tolerant
990A - 12
ILLINOIS URBAN MANUAL
PRACTICE STANDARD
TREE PROTECTION
In Highly Urbanized Areas with Existing
Green and Gray Infrastructure Conflicts
(each.) CODE 990B
(Source: IN Drainage Handbook)
NOTE: Only use Practice Standard Code
990B when there are green and gray
infrastructure conflicts and when adequate
long-term monitoring of the trees exists.
This standard MUST BE USED ONLY IN
CONSULTATION with a PROFESSIONAL
FORESTER or CERTIFIED ARBORIST.
DEFINITION
The protection of individual trees from
damage during construction operations
in highly urbanized areas where there
are individual trees growing close to
gray urban infrastructure.
PURPOSE
The purpose of this practice is to reduce
damage to and loss of individual trees
during construction by implementing
these pre- to post-construction tree
protection procedures. Tree protection
fencing around the Tree Protection
Critical Root Zone (TPCRZ) as defined
below along with other soil, root and tree
protection measures shall be installed
with this standard in order to maintain
the health and integrity of the tree
resources on site.
CONDITIONS
APPLIES
WHERE
PRACTICE
This standard shall be used in lieu of no
local ordinance or in tandem with local
tree protection ordinances. When
possible, IUM Practice Standard Code
990A -TREE PROTECTION shall be
used instead of IUM Practice Standard
Code 990B. IUM Practice Standard
Code 991- TREE PROTECTIONAUGERING Standard should be used in
conjunction with this standard, as
needed.
This standard takes into consideration
trees next to roads and sidewalks where
there already exists an infrastructure
conflict that can be resolved without
compromise to either the green or gray
infrastructure.
This practice applies on development
sites that are highly urbanized, where
990B - 1
the green and gray infrastructure has
been developed or has grown in close
proximity and where there are individual
trees of importance that need to be
preserved.
Refer to IUM Practice
Standard Code 984 - TREE AND
FOREST
ECOSYSTEM
PRESERVATION for information on
preserving stands of trees. Refer to IUM
Practice Standard Code 990A for TREE
PROTECTION in Moderately Urbanized
Areas to Open Spaces for information
on tree protection in all other areas with
trees.
be protected using the length of the
longest branch as the radius of the
circle. The second technique determines
CRZ by referring to Table 1 Guidelines
for determining tree protection zone
(TPZ) radius for healthy, structurally
sound trees per the International Society
of Arboriculture (ISA) Best Management
Practices for Managing Trees During
Construction. This method measures
the diameter in inches at 4.5 feet above
ground (DBH diameter breast height) in
combination with the trees age and
tolerance to construction. See Table 2
for Species Tolerance Ratings.
CRITERIA
LOCAL AUTHORITIES When working
within the boundary of a municipality,
local authorities such as the Urban
Forester, City Arborist, Municipal
Forester or Horticulturist, or Public
Works officials should be contacted to
determine
locally
enforced
tree
protection/preservation standards.
JULIE Before any work has begun, call
JULIE- (Joint Utility Locating Information
for Excavators) at 800-892-0123 at least
48 hours prior to any work being done.
Equivalent local authorities shall also be
contacted, where applicable.
DETERMINING
THE
TREE
PROTECTION CRITICAL ROOT ZONE
(TPCRZ) Tree Protection starts with
determining the TPCRZ or area where
the majority of roots are located and
where tree protection fencing should be
located. The TPCRZ is located one foot
outside the Critical Root Zone (CRZ).
To determine the CRZ, one of the
following two techniques shall be used.
The first is by using the definition of
CRZ or two feet outside the perimeter of
the leaf canopy or drip line of the tree to
The contractor shall use whichever
method affords the greatest protection
for the tree or whichever creates the
larger CRZ area and then add an
additional one foot to create the TPCRZ
PROFESSIONAL ADVISEMENT IS
REQUIRED IN HIGHLY URBANIZED
AREAS. The TPCRZ is the area to be
protected less the area in conflict with
the gray infrastructure.
Any limited
space design protection measures shall
be made per the advisement of the local
Forestry Professionals and/or Certified
Arborist with tree protection training.
In situations where the green and gray
infrastructure can't be protected in its
entirety, the alternative plans must be
approved by the Professional Forester
or Certified Arborist. IN HIGHLY
URBANIZED AREAS where such space
for protecting the trees does not exist, a
Professional Forester and/or Certified
Arborist must be consulted for any
reduced Tree Protection or Fencing
Standards.
FENCING Per IUM Standard Drawing
IUM-690-B - TREE PROTECTION FENCING, trees to be protected per the
990B - 2
approved construction plan or by local
ordinance shall be protected with
fencing around the Tree Protection
Critical Root Zone (TPCRZ).
Trees to be protected shall require tree
protection fencing to be set at the
TPCRZ as described in the IUM
Standard Drawing IL-690-A-B - TREE
PROTECTIONFENCING and IUM
Construction Specification 91 CHAIN
LINK FENCE.
For projects without
highly significant or historical trees and
that will last for less than six-month
duration, a non-treated wood lath snow
fence or wire-mesh fence shall be used
and solidly anchored to the posts. This
area shall be protected from damage
during construction operations.
For projects over a six-month duration
or trees that are considered significant
or historical, a chain link fence with IUM
Construction Specification 91 CHAIN
LINK FENCE or better (as approved by
the local Forester per local ordinances
singularly or in tandem with the project
Engineer) shall be used. IUM Standard
Drawing
IUM-690-A-B
TREE
PROTECTIONFENCING.
Fencing
shall be a minimum of 4 feet in height.
For chain link fencing, metal posts shall
be placed 6 feet (maximum distance) on
center (OC) and the fencing solidly
anchored to the posts.
SIGNAGE Notices shall be posted on
the fences prohibiting dumping and
disposal of waste near protected trees.
Signs shall be posted that identify the
fenced areas as TPCRZ.
SOIL EROSION CONCERNS
In
HIGHLY URBANIZED AREAS, low use
areas inside the TPCRZ should be
mulched with three to five inches of
premium woodchip mulch.
In HIGHLY URBANIZED AREAS, if foot
or vehicular traffic or construction
activities cannot be kept outside of the
TPCRZ for the entire duration of the
construction, actions shall be taken to
disperse the load, minimizing soil
compaction and mechanical root
damage.
These actions to be implemented by
hand method include:
Applying a minimum of 12 inches
of woodchip mulch to the area,
Laying
three-quarter
inch
minimum thick plywood, beams,
commercial logging or road mats
over a four-plus inch layer of
woodchip mulch,
Any erosion control method used within
the TPCRZ shall be placed by hand and
encompass the area 4 inches out from
the tree trunk to three feet outside the
dripline of the tree, meeting the fence
line set at the TPCRZ. This area shall
be maintained to prevent clearing,
grading and development activities from
encroaching within the TPCRZ.
Outside the TPCRZ, erosion and
sediment control measures shall be
installed to prevent sediment from
reaching the TPCRZ. These measures
include but are not limited to vegetative
filter strips, woodchip mulch and rolled
excelsior blankets. Measures such as
woodchip mulch or excelsior blankets
shall be a minimum of 3 inches deep up
to 5 inches deep, extend out from the
fence 10 feet and shall be continuous
around the perimeter of the fence. Other
methods may be used if approved by
the Professional Forester, Certified
Arborist or equivalent.
990B - 3
Installation shall cause no disturbance
to soils. This area shall be maintained to
prevent
clearing,
grading
and
development activities from encroaching
within the protected TPCRZ.
TRUNK PROTECTION IS REQUIRED
IN HIGHLY URBANIZED AREAS For
sidewalk or other space limited areas,
additional Tree Trunk Protection shall be
used. Tree Trunk Protection shall be
implemented using IUM Standard
Drawing IUM-690-C TREE TRUNK
PROTECTION. This standard requires a
minimum of 2 inch x 8 inch x 8 foot
boards banded continuously around
each trunk to prevent scarring of the
trees shown on the plan or designated
by the Professional Forester or Certified
Arborist. Operations of the equipment
shall not break the plane of the fencing
regardless of Tree Trunk Protection
being installed.
ROOT PROTECTION STRATEGIES In
HIGHLY URBANIZED AREAS, the trees
along sidewalks or other concrete
barriers that are currently within the
dripline of the tree shall be enclosed
with chain link fence IUM Construction
Specification 91 CHAIN LINK FENCE
and the IUM Practice Standard Code
991 TREE PROTECTION AUGERING
shall be used in these cases. Other
root/soil management techniques listed
below can also be incorporated into the
job specifications.
TRENCHING IS NOT ALLOWED In
HIGHLY URBANIZED AREAS, do not
trench within the TPCRZ of the
protected tree. If there is a potential to
impact the critical root zone, then
augering must be used by following IUM
Practice Standard Code 991 - TREE
PROTECTION-AUGERING. Also use
IUM Standard Drawings IUM-690-C
TREE TRUNK PROTECTION and IUM
Standard Drawings IUM-690-D TREE
ROOT PROTECTION FOR AUGERING
PRACTICES (Highly Urbanized Areas).
In areas where green and gray
infrastructure are intertwined, there must
be consultation with a local Professional
Forester or Certified Arborist concerning
species tolerance to the construction
practices. Refer to Table 2 - Tree
Species Tolerance to Root Severance
and Soil Compaction has been added
as a reference.
ROOT/SOIL
MANAGEMENT
No
construction activities, including the
placement of topsoil manually, shall be
permitted within the TPCRZ. Adding of
woodchip mulch shall be done manually
as specified in the contract, construction
plan or equivalent document.
All
roadways, parking areas, and storage
areas,
parking,
maneuvering
of
machinery, stockpiling of materials, or
any other construction activities will not
be allowed upon unpaved areas located
within 10 feet of the TPCRZ of trees and
plants designated to be protected.
In HIGHLY URBANIZED areas where
the infrastructure is close to the trunk of
the tree and the roots are one half inch
or greater in diameter, trenches should
be excavated by hand, air spade or low
pressure hydro excavation. It is
mandatory to tunnel under woody roots
rather than cutting them.
WHEN TO START PRACTICE
All
required protection measures shall be
installed prior to the commencement of
any site development activity and shall
remain in place and in working,
functional
order
until
all
site
development activities have ceased or
the surrounding area has been
990B - 4
stabilized. If at any time fencing has
been damaged, work shall be halted
and fencing replaced at Contractor's
cost. Once fencing has been replaced,
work shall commence. At no point
during site development shall protected
trees be left without fencing.
NO CHANGES IN CONTOUR Special
care shall be taken to follow the natural
drainage patterns to avoid unnatural
flow to protected trees. Changes in
contour could also cause run-off with
salt or herbicides that could harm the
trees. Any changes to topography can
cause the tree to get reduced or
increased moisture over time thus
eventually killing the tree.
Water
drainage patterns should remain the
same.
Removal of topsoil around the tree is
prohibited. The original grade shall be
maintained. Any woody vegetation to be
removed around the trees shall be cut
out at the plant base by the appropriate
tools to avoid roots.
BRANCH or ROOT PROTECTION AND
BRANCH/ROOT PRUNING
In
situations where the plan, as approved
by the Professional Forester or Certified
Arborist, requires severing tree roots,
the root pruning shall be done using an
approved mechanical root pruning saw
or industry authorized pruning tool. The
appropriate pruning saws and tool(s),
specifically designed for cutting wood
are defined by the International Society
of Arboriculture pruning standard and
associated
American
National
Standards Institute ANSI standards. The
pruning cut shall be a clean cut. This
operation shall be performed prior to
digging where noted on the plans and
overseen by a Professional Forester or
Certified Arborist.
Roots of protected trees impacted
outside the fenced TPCRZ shall be
pruned according to the International
Society
of
Arboriculture
Pruning
Standard and associated American
National Standards Institute ANSI A300
Standards. All roots impacted shall be
pruned under the supervision of a
Professional Forester or Certified
Arborist and meet or exceed ISA, ANSI
A300 or approved Tree Care Industry
Standards. A Professional Forester or
Certified Arborist shall be onsite during
the entirety of root pruning. Note shall
be taken of any roots greater than ½
inch that are severed since this could
impact the safety and integrity of the
tree resources that the local unit of
government or person has to manage in
the future.
The use of heavy equipment such as a
backhoe for tree root pruning shall be
prohibited. Axes, shovels, back hoes or
other such potential severing devises
not specifically engineered for tree root
pruning shall not be used. Removal or
breaking off branches of the above
types of protected trees will not be
allowed.
REMOVALS Trees deemed by the local
Professional Forester or Certified
Arborist to be at risk for current or future
damage to a person or property should
be removed. Trees not identified to be
protected per local ordinance or
construction plans may be removed per
the advisement of the local Forester in
charge.
All measures must be installed
according to a site-specific plan and in
accordance with all applicable local,
state, and federal laws and regulations.
990B - 5
CONSIDERATIONS
For highly significant trees consider
increasing the Tree Protection Critical
Root Zone (TPCRZ) to 2 to 3 times to
further minimize impact to tree roots.
Also consider protecting the tree trunk
using IUM Standard Drawing IUM 690-C
TREE TRUNK PROTECTION in all
situations where the working conditions
are close enough that the tree trunk
might be impacted. Operations of the
equipment should not break the plane of
the fencing regardless of the type of tree
trunk protection installed
A Professional Forester or Certified
Arborist shall be consulted for any
clearing of trees and any actions that
deviate from criteria within this standard.
On-site supervision is recommended.
The dripline/leaf canopy shall be shown
on the plan sheet to scale, (not only by
symbol), to provide a better basis for
site development evaluation.
Trees to be saved should be evaluated
using the following criteria:
1. Species and condition (maintain a
diversity of moderate to slower
growing trees in good condition),
2. Above the minimum inches of tree
diameter as designated by local
ordinance.
3. Future potential safety and long-term
suitability of the tree for its present
location,
4. Length of time to mitigate losses,
5. Cost of mitigating tree losses,
6. Expected long-term maintenance
costs for the tree compared to other
trees of the same age/size,
7. Soil
erosion
prevention
and
reduction of storm water runoff,
8. The number of other trees growing
under the same conditions and the
precedent that would be set by
removing the tree in question,
9. Impact on
aesthetics,
property
value
and
10. Ability to screen noise and visual
improprieties or ability to enhance
privacy,
11. Ability to moderate temperature
changes, provide shade and reduce
wind forces,
12. Per local ordinance in consultation
with the local Professional Forester
or Certified Arborist, determine if the
tree(s) within the project area has
historic, big, unique or protected
designation. Consultation with the
local Municipal/Professional Forester
or Certified Arborist is required.
If the entire TPCRZ cannot be protected
and the area is reduced on one or more
sides, then consideration should be
given to increasing the TPCRZ on the
opposite side or remaining sides of the
tree in circumstances where this
strategy would benefit the trees
longevity.
Trees to be removed should be
evaluated using the following criteria:
1. In the opinion of the Professional
Forester or Certified Arborist, there is
a clear and reasonable risk of failure
that could cause injury or property
990B - 6
damage including existing utility
service and no corrective measures
are feasible.
2. The tree is dead.
3. The tree is in poor condition with
several dead branches or major
crack(s).
4. Contiguous and fatal disease is
present as diagnosed by a trained
Entomologist, Plant Pathologist or
Professional Forester.
5. Tree is below the minimum inches in
diameter as designated by local
ordinance.
6. Current tree damage is beyond
repair or the tree is in extremely poor
shape due to storm damage or
previous mechanical injury.
7. There is a potential of the tree to
damage existing or future hardscape
features such as driveways or
sidewalks and there is no gray
infrastructure alternative.
8. There is no feasible way to avoid
disturbing the soil around, grading
over, or placing a hardened surface
within the TPCRZ and the tree is an
oak, hickory, red bud, horse
chestnut, Kentucky coffee tree, larch,
honey
locust,
or
conifer.
Consultation with a Professional
Forester is required prior to using
these criteria for tree removal.
9. Tree has a greater than 45-degree
lean toward traffic or another target
or it creates an unsafe clearance or
visual
barrier/sight
line
for
pedestrians or vehicular traffic.
10. Tree is a fast growing or a weak
wooded tree that is invasive such as
box elder, silver maple, tree of
heaven, Russian olive or black
cherry. Exceptions may be made for
large healthy specimens of these
species.
11. Tree is within five feet of a structure
or, when mature, will have a canopy
spread that will overlap the structure.
Consult with a Professional Forester
or Certified Arborist.
12. The tree could be successfully
transplanted with a tree spade onto
another site.
13. Trees that are non-native species or
invasive.
14. Upon consultation with the local
forestry officials or a Professional
Forester or Certified Arborist, it is
determined that the increase in gray
infrastructure will severely limit water
supply and the new site condition
would not allow the tree to survive
and there is no way to change the
site plan to avoid or compensate for
these changes.
A mitigation plan for damaged trees and
removed trees should be prepared in
consultation
with
a
Professional
Forester or Certified Arborist and
included with construction plans and
contract documents. A one for one tree
replacement policy or greater should be
implemented.
When site soil resources have been
greatly altered, it is recommended a soil
restoration strategy be implemented by
non-mechanical methods such as:
990B - 7
1. Scarifying compacted areas,
At a minimum include the following
items:
2. Adding top soil to the original grade
in areas of extreme erosion,
3. Adding about 3-4 inches of woodchip
mulch,
4. Adding a structural soil system,
5. When trees are to be within 25 feet
of gray infrastructure pervious paving
materials should be used. Install
aeration vents in impervious paving.
Use paving materials requiring a
minimum amount of excavation such
as reinforced concrete vs. asphalt.
Design traffic patterns to avoid heavy
loads adjacent to trees. Specify
minimum
subgrade
compaction
under pavement near dripline.
6. If construction is during severe
drought
conditions,
consider
watering
the
tree
per
the
recommendations of a Professional
Forester or Certified Arborist.
For areas with mixed forest in
moderately or highly developed areas,
multiple standards may need to be
used.
1. Identify all existing trees by species,
location, diameter (at 4½ feet above
the ground) and condition. Clearly
indicate the trees and/or branches to
be removed and those to be saved
including their TPCRZ. All pruning
must be done by a Professional
Forester
or
Certified
Arborist
according to the ANSI A300 (Part 1)
standards.
2. Identify locations of roadways,
storage areas, truck clean-out areas,
and parking pads in relationship to
the trees to be protected.
3. Identify location, type and height of
fencing to be used to protect trees,
including the distance for placing the
fencing around the TPCRZ. The
TPCRZ must be drawn to scale on
the plan.
4. Provide signage detail including
verbiage to be used on the signs,
type of materials used for signs and
location of signs on fencing.
5. Designate the TPCRZ and tree trunk
protection on the plan.
6. Identify soil sedimentation and
protection measures outside the
TPCRZ.
PLANS AND SPECIFICATIONS
A Professional Forester and/or Certified
Arborist should be consulted in the
design and planning stages of the
project.
Plans and specifications for tree
protection shall be in keeping with this
standard and will describe the
requirements for applying the practice.
All plans shall include the installation,
inspection and maintenance schedules
with the responsible party identified.
Fees for non-compliance per local
ordinance should be noted.
IUM Standard Drawing IUM-690-A-B
TREE PROTECTION FENCING; IUM
Standard Drawing IUM-690-C TREE
990B - 8
TRUNK PROTECTION; IUM Standard
Drawing IUM-690-D TREE ROOT
PROTECTION
FOR
AUGERING
PRACTICES (Highly Urbanized Areas)
may be used as the plan sheets.
All damage to tree roots and branches
shall
be
pruned
according
to
International Society of Arboriculture
and Tree Care Industry Association
Pruning Standards.
For root management purposes a 25
foot protected area where no equipment
or activity is conducted outside the
TPCRZ will afford the tree the best
chance of survival.
REFERENCES
OPERATION AND MAINTENANCE
USDA FS How to Prune Trees
http://na.fs.fed.us/pubs/detail.cfm?id=26
02
The protective signs, fences and tree
trunk protection will be removed only
after all construction work has been
finished and the site has been inspected
by a Professional Forester for damages
to the trees.
On active construction sites, it is
recommended that trees be inspected
daily to every 7 days for compliance.
Inspections shall include a listing of
trees with:
1. Damage to trunks,
Websites
International Society of Arboriculture
http://www.isaarbor.com/store/category.aspx?cid=91
Illinois Department of Natural Resources
Urban and Community Forestry Web
Page Technical Resources
http://www.dnr.illinois.gov/conservation/
Forestry/UrbanForestry/Pages/default.a
spx
Morton Arboretum. 2015. Selecting
and Planting Trees.
The Morton
Arboretum,
Lisle,
IL
http://www.mortonarb.org/treesplants/tree-and-plant-selection-0
Publications
2. Damage to branches,
American National Standards for Tree
Care Operations Trees, Shrubs, and
Other Woody Plant Maintenance Standard Practice (Pruning) ANSI A300
(Part 1)
3. Mounding of soil around the trunk,
4. Evidence of root damage,
5. Evidence of improper pruning,
6. Notice of unauthorized changes to
the topography,
7. Other infractions to the site around
the tree such as chemical spills and
soil compaction.
American National Standards for
Institute, Inc. Safety Requirements for
Tree Care Operations, Z133.1 most
current version.
American Association of Nurserymen,
2014. American Standards for Nursery
Stock. ANSI Z60.1. American National
990B - 9
Standards Institute, Inc., Washington
D.C.
Community Forestry Program Tree
Planting Standards, Springfield, IL
Clark and Metheny, 1998. Trees and
Development: A Technical Guide to
Preservation of Trees During Land
Development. International Society of
Arboriculture, Champaign, IL
International Society of Arboriculture.
ISA's Best Management Practices:
Managing Trees During Construction.
International Society of Arboriculture,
Champaign, IL
Fazio, J.R., ed., 2011. How to Save
Trees During Construction. Tree City
USA Bulletin #7. The National Arbor
Day Foundation, Nebraska City, NE
Miller, Nancy, David M. Rathke and
Gary R. Johnson. 1999. Protecting
Trees from Construction Damage: A
Homeowner's Guide. University of
Minnesota Extension.
Fazio, J.R., ed., 2010. A Systematic
Approach to Building With Trees. Tree
City USA Bulletin #20. The National
Arbor Day Foundation, Nebraska City,
NE
Fazio, J.R., ed., 2013 How to Manage
Community Natural Areas. Tree City
USA Bulletin #27. The National Arbor
Day Foundation, Nebraska City, NE
Fazio, J.R Trenching and Tunneling
Near Trees, The National Arbor Day
Foundation, Nebraska City, NE
Gilman, Edward and Sharon Lilly. 2008.
Best Management Practices Tree
Pruning.
International
Society
of
Arboriculture.
Gulick, Jennifer, Senior Urban Forester.
2015. Major Construction Impacts and
Methods to Minimize Damage. Davey
Resources Group.
Hightshoe. G.L.1988. Native Trees and
Shrubs and Vines for Urban and Rural
America. Van Nostrand Reinhold, New
York, NY 10003. 819 P.
Illinois
Department
Resources,
Division
Resources,
2015.
of
Natural
of
Forest
Urban
and
Morton Arboretum. 2015. Selecting
and Planting Trees.
The Morton
Arboretum, Lisle, IL
Pirone's Tree Maintenance. 7th Edition
Smiley, E. Thomas and Kelby Fite.
October 2016. Preserving Trees During
Construction Arborist News Volume 25
Number 5. International Society of
Arboriculture, Champaign, IL
Standard Specifications for Road and
bridge Construction, 2012. Illinois
Department of Transportiation.
Tree Care Industry Association. 2015.
ANSI A300 Pruning Standards Part 1.
Tree
Care
Industry
Association.
American National Standards Institute,
Inc.
Tree Care Industry Association. 2012.
ANSI A300 Construction Management
Part 5. Tree Care Industry Association.
Watson, G. and E.B. Himelick, 1997.
Principles and Practices of Planting
Trees and Shrubs. International Society
of Arboriculture, Champaign, IL
990B - 10
Wenger, K, 1996.
The Forestry
Handbook.
Society of American
Foresters, Bethesda, MD
Videos
Root Injury and Tree Health. Illinois
Arborist
Association,
the
Morton
Arboretum, the USDA Forest Service
and the International Society of
Arboriculture.
Trenching and Tunneling: A Video
Guide for Excavating Around Trees.
The Davey Resource Group.
The
International Society of Arboriculture
and the Utility Arborist Association.
September, 2017
990B - 11
urbst990B.doc
Table 1. Guidelines for determining tree protection zone (TPZ) radius for healthy,
structurally sound trees per the ISA Best Management Practices: Managing Trees
During Construction.
Species
Tolerance
Relative
Tree age*
TPZ Multiplication
Factor
High
Young
Mature
Overmature
6
8
12
Medium
Young
Mature
Overmature
8
12
15
Low
Young
Mature
Overmature
12
15
18
DBH (inches) x TPZ Multiplication Factor = TPZ radius (inches)
Note: TPZ is the same as the CRZ in this standard.
Consult with a local Professional Forester or Certified Arborist
990B - 12
TABLE 2. TREE Species Tolerance to Root Severance and Soil Compaction
TREE SPECIES
ROOT SEVERANCE Tolerance
Soil Compaction Tolerance
Basswood
Intermediate
Sensitive
Blue beech
Sensitive
Sensitive
Butternut
Sensitive
Intermediate
Paper birch
Intermediate
Sensitive
River birch
Tolerant
Tolerant
Boxelder
Tolerant
Tolerant
Ohio Buckeye
Intermediate
Intermediate
Catalpa
Intermediate
Tolerant
Kentucky Coffeetree
Intermediate
Intermediate
Eastern Cottonwood
Tolerant
Tolerant
Red-Osier Dogwood
Tolerant
Intermediate
American Elm
Tolerant
Intermediate
Slippery Elm
Tolerant
Intermediate
Hackberry
Tolerant
Intermediate
Hawthorn
Intermediate
Intermediate
Bitternut Hickory
Intermediate
Intermediate
Honeylocust
Tolerant
Intermediate
Ironwood
Sensitive
Sensitive
Black Locust
Tolerant
Sensitive
Red maple
Tolerant
Tolerant
Silver maple
Tolerant
Tolerant
Sugar Maple
Intermediate
Sensitive
Mountain ash
Tolerant
Intermediate
990B - 13
Black oak
Sensitive
Sensitive
Bur oak
Moderately Tolerant
Intermediate
Northern Pin Oak
Sensitive
Sensitive
Red Oak
Moderately Tolerant
Sensitive
Bicolor or Swamp Oak
Intermediate
Tolerant
White Oak
Sensitive
Sensitive
Wild Plum
Tolerant
Sensitive
Serviceberry
Intermediate
Sensitive
Black Walnut
Sensitive
Intermediate
Black Willow
Tolerant
Tolerant
990B - 14
TREE PROTECTION - FENCING
(Moderately Urbanized to Open Space Areas)
Drip Line
2' Minimum CRZ
(Critical Root Zone)
1' Minimum TPCRZ (Tree
Protection Critical Root
Zone) or CFEZ (Critical
Forest Edge Zone) for
forested areas.
Snow Fence
Wire Mesh Fence
Chain Link Fence
SIDE VIEW
6' Max
Mi
n
Post
48"
1. Call J.U.L.I.E. (800-892-0123) for the
location of existing utilities 48 hours
prior to commencement of work.
24"
Ground
Surface
NOTES:
Max
Fence
2. The CRZ is located 2' from the
POST AND FENCE DETAIL
farthest outreaching branch (drip edge)
or the distance as determined by the
ISA trunk diameter method or whichever is greater.
3. The fence shall be located 1' from the Critical Root Zone (CRZ) of
the protected tree, thus creating the Tree Protection Critical Root
Zone (TPCRZ) and the Critical Forest Edge Zone (CFEZ) for forested
areas.
4. Fence Posts shall be either 6' steel posts @ 1.33Lbs./Ft. or 2" x 2"
nominal wood posts.
5. For projects without highly significant or historical trees and that
will last for less than 6 months duration, a non-treated wood lath
snow fence or wire mesh fencing shall be used with appropriate posts
that are securely anchored into the ground. For projects over 6
months in duration or trees considered significant or historical, a
chain link fence with Construction Specification Chain Link Fence IUM
91 or better (as approved by the local Forester per local ordinances
singularly or in tandem with the project Engineer) shall be used. Fencing
shall be a minimum height of 4'. For chain link fencing, metal posts shall
be placed 6' on center (OC) and the fencing securely anchored to the
post.
6. Outside the TPCRZ or CFEZ, erosion and sediment control measures shall
be installed to prevent sediment reaching the TPCRZ or the CFEZ. These
measures shall extend out from the fence 10' and shall be continuous
around the perimeter of the fence. These measures include, but are not
limited to vegetative filter strip, rolled excelsior blankets and mulch
with a 3" to 5" depth. Other measures may be used if approved by the
Professional Forester, Certified Arborist or Horticulturalist. Installation
shall cause no disturbance to soils.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-A
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
1
OF
1
09-14-2017
TREE PROTECTION - FENCING
(Highly Urbanized Areas)
3' TPCRZ and CFEZ
(for forested areas)
(Typ.)
Property Line
P
L
Existing Sidewalk
2' CRZ (Typ.)
(gray infrastructure)
Tree Canopy
Tree Trunk
Drip Edge or Line
(furthest reach
Fence Post
of canopy)
Fence at TPCRZ
Existing Street
2-3" (typical)
(gray infrastructure)
Back of Curb
AERIAL VIEW
(Large Tree)
Property Line
2' CRZ (Typ.)
P
L
Existing Sidewalk
3' TPCRZ and CFEZ
(gray infrastructure)
(for forested areas)
Tree Canopy
Fence Post
Drip Edge or Line
(furthest reach
Fence at TPCRZ
of canopy)
Tree Trunk
AERIAL VIEW
Back of Curb
(Small Tree)
2-3" (typical)
Existing Street
(gray infrastructure)
Notes:
1.
Call J.U.L.I.E. (800-892-0123) for the location of existing utilities 48
hours prior to commencement of work.
2. The CRZ is located 2' from the farthest outreaching branch (drip
edge) or the distance as determined by the ISA trunk diameter
method or whichever is greater.
3.
On sides of the tree not constricted by gray infrastructure, the
fence shall be located 1 foot from the Critical Root Zone (CRZ) of
the protected tree, thus creating the Tree Protection Critical
Root Zone (TPCRZ). The Critical Forest Edge Zone (CFEZ), for
forested areas, shall also be located at the TPCRZ.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-B
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
1
OF
2
09-14-2017
TREE PROTECTION - FENCING
(Highly Urbanized Areas)
Notes: (cont.)
4.
On sides of the tree where there is gray infrastructure conflict
the fence shall be 3 to 4 inches from the structure. Where the
structure is a sidewalk and the CRZ goes beyond the sidewalk to
the adjoining greenspace, the Tree Protection Fencing shall continue
to the CRZ without impeding the flow of the traffic of the sidewalk.
5.
Fence Posts shall be either 6' steel posts @ 1.33Lbs./Ft. or 2"
x 2" nominal wood posts.
6.
A chain link fence with Construction Specification Chain Link Fence
IUM 91 or better (as approved by the local Forester per local
ordinances singularly or in tandem with the project Engineer) shall
be used. Fencing shall be a minimum height of 4'. Metal posts shall be
placed 6' on center (OC) and fencing is securely anchored to the
ground.
7.
Outside the TPCRZ, erosion and sediment control measures shall be
installed to prevent sediment reaching the TPCRZ. These measures
shall extend out from the fence 10' and shall be continuous around
the perimeter of the fence. These measures include, but are not
limited to vegetative filter strip, rolled excelsior blankets and
woodchip mulch with a 3" to 5" depth. Other methods may be used if
approved by the Professional Forester, Certified Arborist or
Horticulturalist. Installation shall cause no disturbance to soils.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-B
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
2
OF
2
09-14-2017
*
6"
TREE TRUNK PROTECTION
Protective cloth
8' (mi
n.
)
(burlap or better)
Outer bands
Banding material
stapled to back
* Protective Cloth
extension
of boards
2" x 8" boards
1" maximum
8"
*
3"
(height varies)
8'-9" (mi
n.
)
SIDE VIEW
Protective cloth
for tree wrap
Notes
1.
The contractor shall provide 2" x 8" boards banded
continuously around each trunk with a protective cloth
(such as burlap or better) placed between the boards
and the tree to prevent scarring of the tree being
protected. The height of the boards is variable due to
height of tree being protected. Trees to be protected
shall be shown in the plans or designated by the
Professional Forester or Certified Arborist.
2. The protective cloth shall extend past both the top and
bottom of the boards as shown in the detail. Width of wrap
material varies. For fabric that does not meet the required
height, fabric shall overlap a minimum of 6" and shall be spliced
to avoid slippage.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-C
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
1
OF
1
09-14-2017
TREE ROOT PROTECTION FOR AUGERING PRACTICES
Drip Edge
CRZ
2'
1'
TPCRZ or CFEZ
A
B
B
4.5'
Entry Pit
Exit Pit
C
Root Envelope
Directional Drill
Straight Directional Drill
Sidewalk
Tree Trunk
AUGURING REQUIREMENTS
Curb and Gutter
B
A
4.
5'
A
(Diameter of
tree at 4.5'
above ground)
Tree
B
C
Distance
Depth of
Diameter of auguring augering
(inches) from tree
(feet)
trunk*
B
n
i
a
d
e
r
a
3
2 1/2
5-9
5
3
10-14
10
3 1/2
15-19
12
3 1/2
15
4
r
o
P
(feet)
1-4
M
k
w
a
y
each side
C
20
OR
TRENCHING AND TUNNELING ISOMETRIC VIEW
MORE
* dimension is from existing
ground to the top of
augering sleeve.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-D
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
1
OF
2
09-14-2017
TREE ROOT PROTECTION FOR AUGERING PRACTICES
Tree Trunk
Drip Edge
2'
Critical Root Zone (CRZ)
3'
Tree Protection Critical
Root Zone (TPCRZ)
ISOMETRIC VIEW OF CRZ AND TPCRZ
Notes
1. In highly urbanized areas, where the gray infrastructure is in
conflict with the green infrastructure, horizontal directional
drilling or tunneling is required. Trenching shall not be done within
the TPCRZ of the tree. Root pruning shall be employed as a last
resort when viable alternatives to severing the roots cannot be
found.
2. In areas of conflict, there shall be consultation with a Professional
Forester, Arborist or Horticulturist concerning species tolerance to
the practices, techniques and tools specifically used to protect the
tree's roots. Only tools designed specifically for root pruning shall
be used. Other tools, such as shovels, axes, backhoes and any other
tool not specific to root pruning shall be prohibited.
3. Roots must not be removed from more than one side of the tree in
any given year.
4. All excavation holes are to be covered in a wet tarp or wet burlap
and kept moist for the duration of the construction project to
protect the roots from desiccation (roots drying out). In some
situations, it may be necessary to hand dig trenches, employ water
excavation or an air spade to locate and preserve the roots.
5. Top soil shall be used to backfill the excavated area within one hour
of cutting roots and the tree shall be watered within 24 hours of
backfilling.
6. All roots impacted shall be properly pruned according to the
International Society of Arborculture (ISA) Pruning Standards and
associated American National Standards Insitute (ANSI) Standards.
Consultation with a Professional Forester, Certified Arborist or
Horticulturist is required on all tree roots greater than 1/2" in
diameter.
7. On site inspections conducted by a Professional Forester, Certified
Aborist or Horticulturist are recommended to determine compliance
with augering specifications.
REFERENCE
STANDARD DWG. NO.
Project
IUM-690-D
Designed
Date
Checked
Date
SHEET
Approved
Date
DATE
2
OF
2
09-14-2017