Blt Handbook

8/4/2019 Blt Handbook

1/98

Gwinnett County

Buffer, Landscape and Tree

Ordinance & Handbook

Gwinnett County, Georgia

Department of Planning & Development446 West Crogan Street, Lawrenceville, GA 30045

678-518-6000www.gwinnettcounty.com

Revised December 2007Reprinted December 2008

2004 Award Recipient from the Georgia Urban Forest Council2004 Award Recipient from the Georgia Urban Forest Council2004 Award Recipient from the Georgia Urban Forest Council2004 Award Recipient from the Georgia Urban Forest Council


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Gwinnett County

Buffer, Landscape and TreeOrdinance & Handbook


Department of Planning & Development

1st

Printing: July, 2000

Adopted December 22, 1992

Amended October 26, 1999

Second Amendment May 22, 2001

Third Amendment August 26, 2003

Fourth Amendment December 11, 2007

Copyright 2008 By Gwinnett County Government, Department of Planning & Development.


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Table of Contents TOC.1

Gwinnett County Buffer, Landscape and Tree Ordinance & Guidelines

Table of Contents

1. Intent, Purpose and Title.

1.1. Intent. 1

1.1. Purpose. 1

1.2. Title. 2

2. Definitions.

2.1 Definitions of Words and Phrases. 3

3. Buffer Regulations.

3.1 Applicability. 10

3.1 Standards for Permanent Buffers. 10

3.2 Standards for Construction Buffers. 13

4. Landscape Regulations.

4.1 Applicability.

4.2 Landscape Strip Planting Requirements. 16

4.3 Off-Street Surface Parking Lot Planting

Requirements. 18

4.4 No-Access Easement Screening Requirements. 19

5. Tree Preservation and Replacement Regulations.

5.1 Applicability and Exemptions. 20

5.2 Permits. 23


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Gwinnett County Buffer, Landscape and Tree Ordinance & Guidelines

5.3 Tree Density Requirements. 26

5.4 Tree Preservation and Replacement Requirements. 30

5.5 Tree Species Lists. 31-Appendix

5.6 Specimen Trees 32

6. Plan and Plat Specifications.

6.1 Water-Efficient Design Consideration. 38

6.2 Buffer and Landscape Plan Specifications 39

6.3 Tree Preservation and/or Replacement

Plan Specifications 40

7. Compliance.

7.1 Artificial Materials Prohibited 43

7.2 Warranty or Maintenance Surety. 43

7.3 Inspection. 43

7.4 Performance Surety. 43

7.5 Continuing Maintenance. 44

8. Enforcement, Violation and Appeals.

8.1 Enforcement. 46

8.2 Violation and Penalty. 46

8.3 Appeals, Modifications and Waivers. 46

9. Adoption.

9.1 Repeal Clause. 48

9.2 Severability 48

9.3 Amendment.


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Appendix

A.1 Canopy Tree Species List

A.2 Parking Lot and Street Tree Species List

A.3 Understory Tree Species List

A.5 Table A-Summary of Applicability and Exemptions

A.7 Table B-Credit for Existing Trees

A.8 Table C-Credit for Specimen Trees

A.9 Table D-Credit for Replacement Trees

A.10 Table E-Specimen Tree Plan Review Items

Figures-Table of Contents

Figure 1 Buffers I-1

Figure 2 Tree Types I-2

Figure 3 How to Measure a Tree I-3

Figure 4 Multi-Stemmed Trees I-4Figure 5 Tree Protection Plan View I-5

Figure 6 Tree Protection I-6

Figure 7 Ten (1) Foot Wide Landscape I-7

Figure 8 Five (5) Foot Wide Landscape Strip I-8

Figure 9 Parking Lot Requirements I-9

Figure 10 Easement Exclusion I-10

Figure 11 Examples of Permit Cards 1-11

Figure 12 Individual Lot Tree Planting I-12Figure 13 Street Trees I-13

Figure 14 Correct Planting Method I-14

Figure 15 Tree Roots I-15

Figure 16 Why Tunneling Saves Trees I-16

Figure 17 Where Can I Find More Information? I-17

Figure 18 Measuring to Determine a Specimen Tree I-18

Figure 19 Critical Root Zone I-19

Figure 20 Easements and Critical Root Zones I-20Figure 21 Removal of Vegetation Under a Specimen Tree I-21

Figure 22 Show Specimen Trees on Which Plans? I-22

Figure 23 Tree Save Signs in English & Spanish I-23

Figure 24 Formula for Specimen Tree Replacement I-24

Figure 25 Avoid Tree/Sign Conflicts I-25


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Figure 26 Dripline & Root Zone I-26

Figure 27 Summons I-27


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Page I

Introduction

Single Family Detached Residence Zoning DistrictsIn the single family detached residence zoning districts (RA-200, R-140, R-LL, R-100, R-100M, R-100 CSO, R-75, R-75M, R-75CSO, R-60, R-L, and R-ZT), there are three (3) requirements. All three(3) requirements must be met prior to approval of a final plat. Street trees may be counted towardmeeting the overall tree density unit requirement. Trees may be either preserved or planted. Preservedtrees are measured at 4.5 feet from the ground. Newly planted trees are measured 6 inches from theground.

Requirement. Two Trees Per Each Lot

Minimum size 2 inches in diameter.

Located anywhere on lot.

Planted trees must be selected from Tree Species List. (Appendix A).

Preserved trees must have protective fencing at the dripline.

Requirement. Street Trees

Trees must be 3 inches in diameter (measured at 6 inches from ground level).

Plan required which indicates species, placement, size, and number of trees.

Trees planted three (3) feet from curb and within right-of-way.

One tree is required for every 50 feet of street frontage. Twice the length of street in feet

calculates number of required trees, but trees can be spaced differently for best placement. Planting required along both sides of new streets.

Developer/subdivider plants trees and provides warranty for one (1) year.

Planting done when construction is complete.

Property owners association responsible for care & maintenance.

Street trees must be selected from Parking Lot and Street Tree list.(A.2)

Planning & Development staff prepared this document to assist with the administration of this ordinance. Itspurpose is to provide the user with the legal interpretative language in a plain, easy to understand comparativeformat. The legal text is found on the left side of each page and the interpretive text is found on the right side.We hope that you find this document helpful. The staff appreciates any comments or suggestions you may haveconcerning this document. Comments can be forwarded to staff at 678.518.6000.

Summary of Buffer, Landscape, and Tree Ordinance


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Page II

Requirement. 16 Tree Density Units (TDU) per acre

Tree Preservation and Replacement Plan (TPRP) required.

Planted trees must be selected from Tree Species List.

Preserved trees must be in groups of three (3) or more to obtain credit.

Street trees may be counted toward meeting the TDU credit.

Multifamily and Non-Residential Developments

Office, commercial, industrial, multifamily, and other non-residential developments (such aschurches) have landscaping requirements as follows:

Overall Site

Tree Preservation and Replacement Plan (TPRP) required. Sixteen (16) Tree Density Units per acre.

(Exception: Activity Center/Corridor Overlay District requires 20 Tree Density Units per acre).

Irrigation is not required but recommended. A ten (10) foot wide landscape strip is required along road frontage(s). Ratio is one (1)

Tree per 25 feet and one (1) shrub per 25 feet of strip length. Where required, 5-foot wide landscape strips required with one (1) tree and one (1) shrub for

each 50 linear feet. Plants in landscape strips may be grouped or clustered. Compliance with Tree Preservation and Replacement Plan (TPRP) prior to obtaining a

Certificate of Occupancy (CO). Land Disturbance Permits (LDP) for clearing, clearing andgrubbing, and grading only also requires compliance with the TPRP.

Parking Lots

One (1) tree per every 7 parking spaces.

Every parking space within 60 feet of the trunk of a tree.

For canopy trees, the planting island size is at least 200 square feet. If shared with othertrees, 80 square feet for each additional tree is required.

For understory trees, planting island size is at least 100 square feet. If shared with othertrees, 40 square feet for each additional tree is required.

Minimum sizes:

Deciduous trees-2 inch diameter. (Deciduous trees lose their leaves each fall.)

Evergreen trees-6 feet high.

Trees are measured:

- 6 inches from ground for newly planted trees.- 4.5 feet for existing trees.

Painted or striped islands larger than 50 square feet not allowed.

Areas within islands must have vegetated or mulched ground covers.

Trees must be selected from Parking Lot and Street Tree list. (A-2)


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Gwinnett County Buffer, Landscape and TreeOrdinance and Guideline

G: \BLT Ordinance Revised 2008 Page 1

Article 1

Intent, Purpose and Title

1.1. Intent.

1.1.1. This ordinance shall apply to all properties orportions thereof located within the unincorporated areasof Gwinnett County, Georgia, to the extent of the provisions contained herein. The Board ofCommissioners hereby finds that the protection andpreservation of trees, the planting of new trees and otherlandscape material, and the provision of buffers betweendissimilar uses as part of the land development process isa public purpose and provides for the public health andgeneral welfare.

1.2. Purpose.

1.2.1. The purpose of this ordinance is to preserveand enhance the County's natural environment. This isaccomplished through the preservation, protection and planting of trees and other landscape material,particularly those trees recognized herein as canopy andunderstory trees, and the provision of natural and/or planted buffers between dissimilar uses as part of theland development process. The ordinance is intended tofurther the County's policy that all development siteswhere trees are most commonly removed will achieveupon project completion a uniform standard related to

tree coverage, landscaping and buffers. In addition, treesare recognized for their importance in shading andcooling, noise and wind reduction, prevention of soilerosion, production of oxygen, dust filtration, fosteringair quality through carbon dioxide absorption, providingwildlife habitat, and contributing to the aesthetic andeconomic value of real property.

1.2.2. This ordinance is also intended to further theCounty's policy of encouraging all individuals or firmswho propose to develop land, and which are required tomeet the requirements of this ordinance, to consider theuse of water-efficient landscaping principles and

techniques (xeriscaping).

Tree Ordinance Guidelines


What is the purpose of the Buffer,

Landscape, & Tree Ordinance?

This ordinance is to preserve, protect

and provide for preservation and

replanting of trees, buffers, andlandscaping for properties in the

unincorporated areas of

Gwinnett County.

Why should I plant trees?

Trees: Shade and cool our atmosphere,

Reduce noise and wind;

Control soil erosion;

Reduce storm water run-off;

Produce oxygen;

Filter dust and other particulate

matter from the air

Improve air quality through

carbon dioxide absorption; Provide wildlife habitat; and,

Contribute to the aesthetic and

economic value of real property.


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1.3. Title.

1.3.1. This ordinance shall be known as "The Buffer,Landscape, and Tree Ordinance of Gwinnett County,Georgia" and may be referred to generally as "TheBuffer Ordinance," or "The Landscape Ordinance," or"The Tree Ordinance," or, as used herein, "thisOrdinance."

When was it adopted?

The Tree Ordinance was first adopted

by the Gwinnett County Board of

Commissioners in 1987. Major

revisions were made in 1991, with the

latest revisions approved in 1999,

2003 and 2007. A copy was placed onthe county web site in 2005.

Vision Statement:

Gwinnett County should continue

to be a place where people want to

work, live and play because itoffers and protects the varied

aspects that comprise quality of

life. One of those aspects is the

countys natural environment.

This ordinance protects existing

trees, encourages replacement and

enhancement of the communitys

tree canopy, and promotes healthy,

sustainable and desirable

surroundings for current andfuture generations.


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Article 2

Definitions

2.1. Definitions of Words and Phrases

2.1.1. In construing the provisions hereof and themeaning of each and every word, term, phrase, or partthereof, where the context will permit, the definitions ofwords as contained in Zoning Resolution supplementedby the following, shall apply:

Buffer: Land area used to visibly separate one use fromanother through screening and distance, to shield orblock noise, light, glare, or visual or other conditions, tominimize physical passage to non-similar areas, or toreduce air pollution, dust, dirt, and litter.

a. Natural, Undisturbed Buffer*: Land area inwhich there is no disturbance and no grading allowed,

except for approved perpendicular access and utilitycrossings.

b. Enhanced Buffer*: Land Area in which thereis no disturbance with the exception for disturbancerelated to additional required plantings, specific to thezoning case and for approved perpendicular access andutility crossings.

c. Landscaped Buffer*: Land Area in whichgrading is allowed and revegetation to a bufferstandard is required specific to zoning case. Replantedper approved landscape plan.

* Per Buffer, Landscape, and Tree Ordinance 3.2.3,Buffers in which vegetation is non-existent or isinadequate to meet the screening requirements of theBuffer, Landscape, and Tree Ordinance shall beplanted with supplemental plantings so as to providean effective visual screen.

d. Construction Buffer: Land Area in whichthere is no disturbance until a Certificate ofOccupancy has been issued on the building lot atwhich time the Construction Buffer is removed.

e. Stream Buffer: The area of land immediatelyadjacent to the banks of state waters in its natural stateof vegetation, which facilitates the protection of waterquality and aquatic habitat. The definition of streambuffer is governed by Georgia Law (O.C.G.A.)12-17-3(2).

What is a Buffer?

Buffers are intended to separate one

use from another through screening

and distance to block noise, light,

glare or other nuisances, They also

reduce air pollution, dust, dirt and

litter.

Buffer widths vary depending upon

the zoning district and conditions ofzoning.

Figure1. Buffers

-PUBLIC STREET-

-PU

BLIC

STREE T

-

C-2 O-I

75BUFFER50BUFFER

R-75


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Canopy Tree:

A tree that, under normal forest conditions, will composethe top layer or canopy of vegetation and generally willreach a mature height of greater than 40 feet.

What is a canopy tree?

Canopy trees:

Grow taller than 40 feet in height at

maturity;

Are typically spaced 40 feet apart, witha minimum of 25 feet between trees if

planted in groups.

Some examples include oak, hickory,

pine and maple trees.

What is a small tree?

Small trees:

Grow to less than 40 feet in height at

maturity;

May be planted under (or within 20

feet of) overhead power lines; and,

Are typically spaced 30 feet apart, with

a minimum of 20 feet between trees if

planted in groups.

Some examples include dogwood and

flowering cherry tree.

Figure 2. Tree Types

DRIP LINE OFTREE

SMALL MATURING TREE

(SMALL)

DRIP LINEOF TREE

GREATERTHAN40

LESSTHAN

40

60 OR MORE

GROUND LEVEL

LARGE MATURING TREE

(CANOPY)


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Clearing: The removal of vegetation from a property,whether by cutting or other means.

Construction Buffer: Land Area in which there is nodisturbance until a Certificate of Occupancy has beenissued on the building lot at which time the ConstructionBuffer is removed.

County: Gwinnett County, Georgia.

Critical Root Zone: The minimum area beneath a treethat must be left undisturbed is Critical Root Zone(CRZ). The CRZ is a concentric circle centering on thespecimen trees trunk with a radius equal in feet to 1.5times the number of inches of the trunks diameter at breast height (4.5). Example: the CRZ radius of atwenty inch (20) diameter tree is 30 feet.

Department: The Gwinnett County Department ofPlanning and Development, as established by the

Gwinnett County Board of Commissioners, and asoperated through the actions and administration of theappointed director of said department or his/herdesignee.

Development Regulations: The adopted regulations providing for the subdivision and development of realproperty within Gwinnett County, Georgia, as amendedfrom time-to-time by the Board of Commissioners ofGwinnett County.

Diameter, Tree: The diameter of a tree measured asfollows: 1) for existing preserved trees, at a point 4.5 feet

above the ground; 2) for new replaced trees, at a point 6inches above the ground.

How do I determine a trees size?

Figure 3. How to Measure a Tree

NEWLY PLANTED TREES

GROUND LEVEL

EXISTING TREES

(1) For newly planted trees:

Measure tree diameter 6 above ground level.

(2) For existing trees:

Measure tree diameter 4-1/2 above ground level.

Note: Minimum size: 2 planted tree.

(1) (2)

6

4 6


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Director: The director of the Department of Planning andDevelopment or his/her designee.

Dripline: A line on the ground established by a verticalplane extending from a tree's outermost branch tips downto the ground; i.e., the line enclosing the area directlybeneath the tree's crown from which rainfall would drip.

Floodplain, 100-Year: Those lands subject to flooding,which have at least a one percent probability of floodingoccurrence in any calendar year; and specifically, thefloodplain as shown on the Flood Boundary andFloodway Map as prepared by the Federal EmergencyManagement Agency (FEMA).

Grading: The placement, removal, or movement of earthby use of mechanical equipment on a property.

Hardwood Tree: Any tree that is not coniferous (conebearing) or needle bearing.

Land Disturbing Permit (LDP): Any permit other than aBuilding Permit issued by Gwinnett County thatauthorizes clearing or grading activities on a site orportion of a site. This permit may be a Clearing, Clearingand Grubbing, Grading, or Development Permit asdefined and authorized by the Development Regulationsof Gwinnett County.

Landscape Strip: Land area located within the boundaryof a lot and required to be set aside and used forlandscaping upon which only limited encroachments are

authorized.

Modification: A type of administrative appeal that maybe granted by the director only where specificallyauthorized in this ordinance.

How do I measure a

multi-stemmed tree?

Figure 4. Multi-Stem Trees

Why are roots important?

Roots are important for survival of the

tree. They provide for the uptake of

water & nutrients and for physical

support. If construction activity

crushes or severs roots close to a tree,

the tree may become unsafe to leave

standing. Protecting the soil aroundthe drip line will help protect the

roots.

8MinimumHeight

TYPICAL MULTITYPICAL MULTITYPICAL MULTITYPICAL MULTI----STEM TREESTEM TREESTEM TREESTEM TREE

Note: Trees may not be accepted if they

have been sheared or rounded over.

TREEFORM3-5TRUNKS

MAXIMUM.

HEIGHT IS

MEASURED ONSINGLE LARGESTSTEM.

GROUND LEVEL


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Monetary Compensation Monies: A dollar amount fora tree or trees that is stored in the tree bank.

Monetary Compensation Value: A unit ofmeasurement, that when multiplied by the tree densityunit allows a given dollar amount for a tree or trees tobe stored in the tree bank.

Screening: A method of shielding or obscuring oneabutting or nearby structure or use from another byopaque fencing, walls, berms, densely plantedvegetation, or the like.

Shrub: A woody plant of relatively low height, asdistinguished from a tree by having several stems ratherthan a single trunk.

Softwood Tree: Any coniferous (cone bearing) tree.

Specimen Tree: Any tree that meets one or more ofthe identification criteria listed in Section 5.6. It is based on the trees size, type, condition, location orhistorical significance. See Section 5.6 for specificcriteria defining specimen trees.

Timber Harvesting: The felling, loading and transportingof timber products (pulpwood, etc.). The term "timberharvesting" may include both clear cutting and selectivecutting of timber.

Tree Bank: (Option One) Actual trees are planted or(Option Two) a place of storage of monetary

compensation for trees.

Tree Banking: (Option One The process of plantingactual trees or (Option Two) the process of storingmonetary compensation monies for trees. The processwill result in the planting of trees at a site within thesame commission district in which the development islocated.

Tree Canopy Calculation: A number given in squarefeet to a tree or group of trees that reflect the overallcanopy at maturity of that tree or trees. See AppendixA Tree Species Lists for the square feet and Section

5.3.3 for calculation requirement.

Tree Density Unit (TDU): A credit assigned to a tree, based on the diameter of the tree, in accordance withtables contained in this ordinance.

What is Open Space?

Open Space is defined in the Zoning

Resolution as: A parcel or area of

land set aside, designated, or reservedfor public use or enjoyment of owners,

occupants and their guests of land

adjoining or neighboring such open

space.

What are TDUs?

TDUs (Tree Density Unit) are based on

the trees size. Density is achieved by

retaining existing trees and/or

planning new ones. Existing trees and

replanted trees have different credit

values. For example: a newly planted

2 diameter tree is credited with .5

TDUs while a 3diameter existing

tree receives the same credit. Credits

are partly based on tree survivability

potential.

The intent of the ordinance is to

establish uniform tree coverage. The

density standards are:

16 TDUs (tree density

units/acre), in general; or,

20 TDUs for overlay districts.


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Tree Density Standard (TDS): The minimum number ofTree Density Units per acre which must be achieved on aproperty.

Tree: Any self-supporting woody perennial plant,usually having a main stem or trunk and many branches,and at maturity normally attaining a trunk diametergreater than 3 inches at any point and a height of over 10feet.

Tree Protection Area (TPA): Any portion of a sitewherein are located existing trees which are proposed tobe preserved in order to comply with the requirementsof this ordinance. The Tree Protection Area shall includeno less than the total area beneath the tree canopy asdefined by the drip line of the tree or group of treescollectively.

Tree Preservation and/or Replacement Plan (TP/RP): Aplan that identifies Tree Protection Areas where existingtrees are to be preserved and where proposed

replacement trees are to be planted on a property to meetminimum requirements, as well as methods of tree protection to be undertaken on the site and otherpertinent information.

Tree Thinning: Selective cutting or thinning of treesonly for the clear purpose of good forestry managementin order to protect said forest from disease or infestationand in no way shall be construed as clear cutting.

Small Tree: A tree that, under normal forest conditions,grows to maturity beneath overstory trees and willgenerally reach a mature height of at least 10 feet but

less than 40 feet.

How can I meet the tree density

standard?

Trees planted to fulfill the parking lot

landscape and landscape strip require-

ments may also be credited towardsfulfilling the tree density require-

ments. Alone, these trees may satisfy

the tree density standard

Or it may be necessary to provide

additional trees.

What is a TPA?

ATree Protection Area (TPA) has: Minimum of 3 existing trees; and,

Tree protection devices at the

drip line.

What is a TP/RP?

A Tree Preservation or

Replacement Plan (TP/RP):

Required for non-residential andmulti-family projects.

Required for one and two family

subdivisions.

What is a small tree?

Small trees:

Grow to less than 40 feet in

height at maturity; and, May be planted under (or within

20 feet of) overhead power lines.

Some examples include dogwood

and flowering cherry trees.


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Xeriscaping: A method of landscaping utilizingmaterials which are water-efficient (refer to Article 6 ofthis ordinance for principles and techniques).

Zoning Buffer: A buffer required by the ZoningResolution or as a condition of zoning, special use orvariance approval for a specific property.

Zoning Resolution: The Zoning Resolution of GwinnettCounty, Georgia, as amended from time-to-time by theBoard of Commissioners of Gwinnett.

Where can I find the recommended

tree species?

A listing ofrecommended species of

both canopy and small trees is

found in Appendix A.

How do I know which trees to

choose?

Tree Selection:

Tree types, canopy or small

trees, must be indicated on the

landscape plan submitted for

approval. Tree species must be selected

from the tree species list found

in Appendix A.

Other species may be used if

approved by the director or the

directors designee.


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Article 3

Buffer Regulations

3.1.1. Applicability.

3.1.1. Buffers shall be required between dissimilardistricts or uses in accordance with the provisions of theZoning Resolution or as a condition of zoning, specialuse or variance approval.

3.2. Standards for Permanent Buffers.

3.2.1. Width of Buffers.Buffers shall meet the minimum width requirementscontained in the Zoning Resolution, except as authorizedto be reduced by the applicable buffer reduction process,

as follows:a. As specified in the Minimum Buffer StripRequirement Table; or, b. As specified in a residential zoning district fora permitted non-residential use (e.g. a church, temple,synagogue, etc.): or,c. As required by a condition of zoning, specialuse, or variance approval.

3.2.2. Screening Requirements.

a. Buffers shall be natural, undisturbed, and freeof encroachments except as authorized by a condition of

zoning, special use or variance approval, or as authorizedherein, and shall contain the existing tree cover andvegetation as well as any supplemental plantings orreplantings as may be required.

b. Buffers shall be of such nature and density soas to screen activities, structures and uses on the propertyfrom view from the normal level of a first story windowon an abutting lot and shall further provide a year-roundeffective visual screen.

c. Buffers required along side property lines shallextend to a street right-of-way line unless otherwise

required by the director in order to observe the sightdistance requirements contained in the DevelopmentRegulations, or as authorized by a condition of zoning,special use, or variance approval.

d. In situations where the required buffer width ispartially or completely contained within an existingeasement (e.g. power or natural gas transmission, etc.),the screening requirements of this Ordinance shall bemet outside of the easement area.

What is a buffer?

Why are they important?

Natural, undisturbed buffers are

required between dissimilar zoning

districts (i.e. between residential and

non-residential zoning districts).

Abuffer is intended to separate one

use from another through screening

and distance and to block noise, light,

glare and other nuisances. It reduces

air pollution, dust, dirt and litter.

County ordinances also require stream

buffers. These aid erosion and storm

water runoff control and are described

in more detail in the Zoning

Resolution.

Typically, a buffer is 25-75 feet in

width and is located where non-residential zoning is adjacent to

residential zoning. Stream buffers

are located adjacent to streams.

The width of a buffer must meet:

The minimum requirements of

the Zoning Resolution; or,

As specified in the conditions of

rezoning, Special Use, orvariance approval.

Abuffer should remain natural and

undisturbed unless enhancement is

necessary.


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3.2.3. Supplemental Plantings.

a. Buffers in which vegetation is non-existent oris inadequate to meet the screening requirements of thisOrdinance shall be planted with supplemental plantingsso as to provide a year-round effective visual screen.

b. Supplemental plantings and replantings shallconsist of evergreen and deciduous trees adaptable to theregion. Deciduous trees shall be 2 inches in diameterand evergreen trees shall be at least 6 feet in height.Evergreen trees planted shall be a minimum of 6 feetin height at time of planting and shall be a specieswhich will achieve a height of at least 20 feet atmaturity. The tree types shall be from Appendix ATree Species List. All shrubs planted shall be a largegrowing species, shall be a minimum of 3 feet in

height at time of planting and shall be a species whichwill achieve a height of at least 10 feet at maturity.

c. All supplemental plantings shall be installed toallow for proper plant growth and maintenance.

d. All supplemental plantings in buffers shall belimited to 33% of one genus of tree. Calculations arerequired on Tree Preservation/ Tree Replacement Plan.

e. Leyland Cypress, Cuppressus leylandii maybe used in supplemental replanting in buffers and shallnot exceed 33% of total buffer trees. Leyland Cypress

is not allowed to fulfill regulatory densityrequirements. Leyland Cypress can be used forscreening purposes.

Structures must be located no closer

than 5 feet to any required buffer,

except stream buffers. Some examples

of structures are walls, parking lots,

and the curb & gutter.

What if the buffer has little or no

vegetation?

A buffer must be planted or replanted

where sparsely vegetated to provide

an effective visual screen. Typically,

this requirement is satisfied by

planting a mixture of evergreen and

deciduous trees and shrubs. It isrequired that no more than 33% of a

single genus be used. Requirements

are for evergreens to be 6 feet high

and deciduous trees to be 2 inches dbh

at time of planting.

Usually, a 50-foot wide buffer would

require four (4) rows of replanted

trees.


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3.2.4. Non-Vegetative Screening.

a. Non-vegetative materials utilized to satisfy thescreening requirements of this Ordinance, in addition tothe use of existing vegetation and/or supplementalplantings, may consist of walls, fences, earthen berms orany combination thereof.

b. If walls or fences are to be utilized, theirplacement and installation shall be such so as to causeminimal disturbance of existing vegetation and locatedso as to provide an effective visual screen.

3.2.5. Disturbance or Encroachments.

a. Ditches, swales, storm water conveyancefacilities, storm water detention ponds, sanitary sewerconveyance facilities, similar facilities, and anyassociated easements, shall not encroach into a bufferexcept that necessary access and utility crossings (e.g.

storm water or sanitary sewer pipes) may encroach intothe buffer as near to perpendicular as practical.

b. Supplemental plantings or replantings ofvegetation, or authorized non-vegetative screeningdevices shall be authorized to encroach into a bufferprovided there is minimal disturbance of any significantexisting vegetation.

c. Land disturbance is authorized in areas of abuffer that are devoid of significant vegetation providedthat the final grade and replantings of vegetation meetthe screening requirements contained herein.

d. Dying, diseased or dead vegetation may beremoved from a buffer provided minimal disturbanceoccurs. Vegetation thus removed shall be replaced wherenecessary to meet the screening requirements containedherein.

3.2.6. Protection During Land Disturbing Activities.

a. During authorized land disturbing activities,buffers shall be clearly demarcated and protected prior tocommencement of, and during, construction.

b. The method of demarcation and protectionutilized shall be in accordance with best managementpractices or as required by the department.

How do buffers help with storm

water management?

Buffers:

Slow down the flow of water;

Prevent erosion;

Filter out particulates in the

water before entering streams; Reduce stream temperatures;

Provide habitat for wildlife; and,

Help prevent pollutants from

entering streams.


21/98



3.3. Standards for Construction Buffers.

3.3.1. Where Required.

Construction buffers shall only be required wherespecifically provided as a condition of zoning, specialuse or variance approval.

3.3.2. Time Constraints.

Construction buffers shall only be in effect during theconstruction period of a project and shall terminate upon project completion. In the case of a residentialsubdivision, a construction buffer shall terminate uponeach individual lot with the issuance of a Certificate ofOccupancy for the principal dwelling.

3.3.3. Disturbance or Encroachments.

a. Construction buffers shall be natural,undisturbed and free of encroachments except asauthorized by a condition of zoning, special use orvariance approval, or as authorized herein.

b. The encroachment of ditches, swales,stormwater conveyance facilities, stormwater detention ponds, sediment basins, sanitary sewer conveyancefacilities, similar facilities, and any associated easements,into a construction buffer shall not be authorized exceptthat necessary access and utility crossings (e.g. storm

water or sanitary sewer pipes), and natural bottomdetention ponds (sediment basins must be located outsideof the construction buffer) and their appurtenantstructures which require no grading and removal of trees,may encroach upon the construction buffer.

c. If the construction buffer on a residential lot isdevoid of existing trees and vegetation, and a tree surveyis submitted to document this situation prior toconducting land disturbing activities (including clearing)on the lot, then the department may authorize theencroachment of a building or structure into theconstruction buffer for a distance not to exceed 10 feet.

What is a construction buffer?

Aconstruction buffer is a type of

buffer that is temporary and only

remains in effect during the

construction of a project.

Please refer to any conditions of

zoning which may apply to the project.

Construction buffers are typically

indicated on final subdivision plats.

What does a Tree Protection Area

look like?

Figure 5. Tree Protection Plan View

DISTURBED / ACTIVEDISTURBED / ACTIVEDISTURBED / ACTIVEDISTURBED / ACTIVECONSTRUCTION AREACONSTRUCTION AREACONSTRUCTION AREACONSTRUCTION AREA

BUFFER / TREE SAVE AREABUFFER / TREE SAVE AREABUFFER / TREE SAVE AREABUFFER / TREE SAVE AREA

BUFFER/TREESAVEAREA

BUFFER/TREESAVEAREA

BUFFER/TREESAVEAREA

BUFFER/TREESAVEAREA

P/L

P/L

P/L

P/L

P/LP/LP/LP/LROWROWROWROW

B/LB/LB/LB/L

ORANGE TREE PROTECTIONORANGE TREE PROTECTIONORANGE TREE PROTECTIONORANGE TREE PROTECTIONFENCINGFENCINGFENCINGFENCING


22/98



3.3.4. Protection During Land Disturbing Activities.

a. During authorized land disturbing activities,construction buffers shall be clearly demarcated and protected prior to commencement of, and during,construction.

The method of demarcation and protection utilized shallbe in accordance with best management practices or asrequired by the department.

3.4. Required Buffers:

a. Street Frontage Buffer is required for newsingle family residential subdivision developmentszoned R-100 Modified, and R-60:Fifty feet (50) in width. The street frontage buffershall remain undisturbed and natural, except forentrance features, necessary street constructionactivities, right of way crossings, and corner right of

way miters or radii. If the required street frontage buffer is void of vegetation, it shall be replanted toprovide an effective visual screen, which may includelandscape berms and decorative fences. The landscape plan shall be submitted, reviewed and approved byStaff Landscape Architect or designee prior toissuance of a development permit. Trees in the StreetFrontage Buffer can be counted toward meeting treedensity units. No Access easements, as described inSection 4.4, shall be included within the StreetFrontage Buffer and shall be landscaped as part of andin accordance with the Street Frontage Bufferrequirements.

b. The Director is herby authorized to grant amodification for compliance with this section.

How can I protect trees during

construction?

Figure 6. Tree Protection

1. No soil disturbance or compaction,construction materials, traffic,trenching, burial pits or other landdisturbing activity are allowed inthe tree protection zone.

2. Tree protection barriers shallextend around the trees with aradius equal to or greater than thedrip line.

3. All tree protection barriers shall beinstalled prior to any grading,construction or other land-disturbing activity. They shall beconstructed using orange safetyfencing on metal posts.

4. Fencing maybe orange plastic orfabric.

Note:

Dead trees and scrub growth shall becut flush with adjacent grade duringthe landscape installation phase.

Orange safety fenceattached to metalposts.

Remove all barriersupon completion ofproject.

No grubbing allowedunder the drip line.

Drip Line Drip Line

4


23/98



Article 4

Landscape Regulations

4.1. Applicability.

4.1.1. Nonresidential and Multi-Family Uses. Nonresidential and multi-family uses shall provide forand maintain landscape plantings on-site as follows:

a. In a Landscape Strip at least 10 feet in widthadjacent to any street right-of-way abutting the propertyand running the length of the entire property frontage;and,

b. In areas adjacent or internal to off-streetparking lots that are required by the Zoning Resolutionto contain more than 5 off-street parking spaces; and,

c. As required by a condition of zoning, specialuse or variance approval.

d. The director is hereby authorized to grant amodification of up to 50% of the 10 foot landscape stripwidth provided the strip is not required by a condition ofzoning, special use, modification, variance or waiverapproval

What is a landscape strip and why

is it important?

Nonresidential and multi-family

developments require a 10-foot wide

landscape strip adjacent to road

rights-of-way and running the entire

length of the property.

Landscape strips:

Filter water runoff; Break up the long expanse of

pavement; and,

Enhance the beauty of the site.

Existing trees that are saved after

development may be utilized to satisfy

this requirement provided they are

located within the boundary of the

landscape strip. Existing trees mayalso be counted toward the

requirement provided they are

protected as shown in Figure 6.


24/98



4.1.2. Residential Subdivisions

Residential subdivisions shall provide for andmaintain landscape plantings on-site as set forth inSection 4.4 in the following circumstances:

a. In no-access easements that are by theDevelopment Regulations along the line of doublefrontage lots abutting upon a major thoroughfare; and,

b. As required by a condition of zoning, specialuse, modification, variance or waiver approval.

4.2. Landscape Strip Planting Requirements.

4.2.1. Ten (10) Foot Wide Landscape Strips.

Landscape Strips which are required to be 10 feet inwidth shall contain landscaping and plantings withinor adjacent to the strip as follows:

a. One (1) tree for each 25 linear feet of striplength shall be provided. Deciduous trees shall be atleast 2 inches in diameter and evergreens trees shall be6 feet in height at time of planting. Trees shall be aspecies native or suitable to this region.

b. One (1) shrub for each 25 linear feet of striplength shall be provide. Each shrub shall be a speciesnative or suitable to this region.

c. Trees and shrubs required herein may beplanted and spaced singly or in groups as authorized

by the Director so long as the total number ofplantings is achieved.

d. The remaining ground area shall be sodded,seeded or hydroseeded with grass, and / or plantedwith groundcover species and / or provided with otherlandscaping material, or any combination thereof..

In one and two-family residential

developments, a landscape strip may

be required as a condition of zoning or

within a no-access easement along

double frontage lots. This is primarilyto prevent vehicular access from the

collector street directly to the

property.

How many plants are required in a

10-foot wide landscape strip?

The number of trees is determined by

the amount of road frontage. Within

the landscape strip, one tree per 25linear feet of property frontage is

required. These trees may be grouped

or clustered; they do not need to be

spaced 25 feet on center.

Figure 7. 10-Foot Wide Planting Strip

The specified ratio indicates the

number of trees and shrubs to beplanted.

The plants may be grouped orclustered.

3 Trees

Example: Red MapleR / W

1 TreeExample: Pin Oak

10-0

1 TreeExample: Pin Oak

120-0

2ShrubsExample:

Dwarf BurfordHolly

3ShrubsExample:

Dwarf BurfordHolly

P/L

P/L

P/L

P/L

PARKING LOTPARKING LOTPARKING LOTPARKING LOT

GRASSGRASSGRASSGRASS

P/LP/LP/LP/L


25/98



4.2.2 Five (5) Foot Wide Landscape Strips.

Landscape Strips which are required to be 5 feet inwidth shall contain landscaping and plantings withinor adjacent to the strip as follows:

a. One (1) tree for each 50 linear feet of striplength shall be provided. Deciduous trees shall be atleast 2 inches in diameter and evergreen trees shall beat least 6 feet in height at time of planting. Trees shallbe a species native or suitable to this region.

b. One (1) shrub for each 50 linear feet of striplength shall be provided. Each shrub shall be a speciesnative or suitable to this region.

c. Trees and shrubs required herein may beplanted and spaced singly or in groups as authorizedby the Director so long as the total number of requiredplantings is achieved.

d. The remaining ground area shall be sodded,seeded or hydroseeded with grass, and / or providedwith other landscaping material, or any combinationthere of.

4.2.3. Landscape Strips Wider than 10 Feet.

Tree and shrub quantities in landscape strips that arerequired to be wider than 10 feet by a condition ofzoning, special use, variance or waiver approval shall be proportional to their width (e.g. a 20 foot widelandscape strip would require two (2) trees and two (2)shrubs for each 25 linear feet of strip length).

How many plants are required in a

five-foot wide landscape strip?

The number of trees is determined by

the amount of landscape strip length

the entire length of the property line.

Within the 5-foot wide landscape strip,

one tree per 50 linear feet of landscape

strip length is required. These trees

may be grouped or clustered; they do

not need to be spaced 50 feet on

center.

Figure 8. Five-Foot Wide Planting Strip

Additional landscape strips of

varying widths may be required as a

condition of approval by any board or

administrative action. Unless planting

details are specifically described by

the conditions, these strips shall

adhere to the planting specifications

proportional to their width.

The specified ratio indicates the number oftrees and shrubs to be planted. The plantsmay be grouped or clustered.

PARKING LOTPARKING LOTPARKING LOTPARKING LOT

GRASSGRASSGRASSGRASS

2 TREESEXAMPLE:

RED MAPLE

3SHRUBSEXAMPLE:

FORSYTHIA

1 TREEEXAMPLE :WILLOW OAK

5555

P/LP/LP/LP/L


26/98



4.2.4. Encroachments Into Landscape Strips.

Required Landscaped Strips shall not be encroachedupon by parking spaces, driveway surfaces or storm

water detention facilities except that driveway crossingsmay traverse such strip as near to a perpendicularalignment as practical. Signs may also be located insuch strip.

4.3. Off-Street Surface Parking Lot PlantingRequirements.

4.3.1. Quantity, Spacing and Planting Standards.Off-street surface parking lots which are required tocontain more than 5 parking spaces shall contain

landscaping and plantings as follows:

a. Trees shall be provided and maintainedadjacent to, and in the interior portions of, parking lots ina ratio of one (1) tree for each seven (7) parking spaces.In addition, every parking space shall be within 60 feetof the trunk of a tree.

b. Deciduous trees shall be at 2 inches in diameterand evergreen trees shall be at least 6 feet in height.Canopy trees listed in Appendix "A", Parking Lot &Street Trees Species List shall be selected, planted, andmaintained. Any plantings beyond the minimumrequirements may come from any of the species lists.

c. The minimum planting area or island for eachcanopy tree shall be at least 200 square feet. If sharedwith other trees, 80 square feet for each additional treeshall be added.

d. The minimum planting area or island for eachunderstory tree shall be 100 square feet. If shared withother trees, 40 square feet for each additional tree shallbe added.

e. Trees shall be planted in areas surroundingthe perimeter of the parking lot and/or shall be planted

in planting areas or islands internal to the parking lot.Trees may be planted and spaced singly or in groups.Each planting area or island shall not be less than 4feet in width in any direction.

Why do we need trees in a parking lot?

Parking lot landscaping:

Increases shade and cools the parking

area

Reduces stormwater run-off andpollutants; and,

Lessens evaporative emissions from

parked cars.

What are the requirements?

Trees are planted within parking lots at a

ratio of 1 tree for every 7 parking spaces. It

is not specified that an island must be

provided but requires a minimum number of

trees to be planted. Trees must be selected

from the Parking Lot and Street Trees

Species list. (A.2)

Figure 9. Parking Lot Planting

Requirements

Landscape Islands:* Minimum 10 feet wide

(back of curb to back of curb)* Minimum 200 square feet per tree

Note: Landscape strip and / or buffer treescan be counted toward the 60 foot requirement.

PUBLIC

STRE ET

PUBLICSTRE ET

PUBLIC

STRE ET

PUBLICSTRE ET

OR

60 Radius

120


27/98



f. Ground areas shall be sodded, seeded orhydroseeded with grass and/or planted withgroundcover species, and/or provided with otherlandscaping material, or any combination thereof.

g. Paved or striped islands greater than 50square feet shall not be allowed. These areas shallcontain landscape plantings.

h. Topping trees is not allowed. Trees removedor having had their tops cut after compliance with thissection shall be replaced with the equivalent inches ofremoved trees.

1. Trees removed due to disease or insectinfestation upon the written advice and findings ofthe County Extension Service or the GeorgiaForestry Commission shall be replaced in

accordance with the minimum standards containedin the ordinance.

2. Appropriate pruning and healthy treemanagement shall be according to the standards asfollowed by the International Society ofArboriculture.

i. Director is hereby authorized to grant amodification of tree species in cases of powereasements.

j. No more than thirty-three percent (33%) of all

proposed trees to be planted may be of any one genus.

4.4. No-Access Easement Screening Requirements.

4.4.1. No-access easements which are required by the Development Regulations, or as a condition ofzoning, special use or variance approval, shall bescreened as follows:

a. Planted with a single line of evergreen trees atleast 6 feet in height and spaced no greater than 10 apart;or,

b. Contain a solid or decorative fence at least 4feet in height; or,

c. Contain such other landscaping treatments orgrade changes that will produce a partial screening effectas authorized by the director.

.

Where are trees planted in parking lots?

Trees must be planted within the

interior area so that each parking

space is within 60 feet or less fromthe trunk of a tree. The intent of the

ordinance is to have some part of each

parking space within 60 feet of a

tree.

Internal landscape space and trees are

required as follows:

Minimum planting area for each

canopy tree is at least 200

square feet. If shared with other

trees, 80 square feet per tree is

added.

Minimum planting area for each

small tree is at least 100 square

feet and if shared with other

trees, 40 square feet per tree is

added.

Planting area must be at least 4 feet

in width in any direction.


28/98



Article 5

Tree Preservation and Replacement Regulations

5.1. Applicability and Exemptions.

5.1.1. This article shall apply to any activity on real property which requires the issuance of a LandDisturbing except as excluded in this section. Table A:Summary of Applicability and Exemptions, at the end ofthis section, summarizes those activities which areexempt from the provisions of this ordinance and thosefor which a Tree Preservation and/or Replacement Planmust be approved prior to issuance of a Land DisturbingPermit.

5.1.2. Grandfathered Projects.

a. This article shall not apply to any portion of a

property included within the limits of a valid LandDisturbing Permit issued prior to the effective date ofthis ordinance, provided that all time constraints relatingto the permit issued shall be observed. In no event shallany grandfathered project be extended for a greater timeperiod than 24 months from the date of enactment of thisordinance.

b. Projects which were included within the limitsof a Land Disturbing Permit issued prior to June 23,1987, which was the effective date of the TreeOrdinance, shall be grandfathered from the requirementsof this article to the extent of the time constraints

imposed upon said permit by the DevelopmentRegulations.

c. The requirements of this article may be waivedby the department for a Land Disturbing Permit which isto proceed with development of a larger project, at least75% of the land area of which has already received apermit or permits initiating clearing or grading activitiesprior to June 23, 1987 which was the effective date ofthe Tree Ordinance.

5.1.3. Horticultural or Agricultural Operations.

a. All plant or tree nurseries and botanicalgardens shall be exempt from the terms and provisions ofthis ordinance in relation to those trees which are beinggrown for relocation and continued growth in theordinary course of business, or for some public purpose.

b. All orchards of trees in active commercialoperation shall be exempt from the terms and provisionsof this ordinance for bona fide agricultural purposesonly.

When is this ordinance applicable?

All new or redeveloped residential

construction; and,

All new or redeveloped non-residential

construction.

What are Grandfathered projects?

The ordinance has grandfathering

provisions to help minimize difficulties

with projects already underway or

partially developed.


29/98



c. Land clearing or clearing and grubbingactivities for clearly agricultural purposes in the RA-200zoning district shall be exempt from the provisions ofthis ordinance.d. Timber harvesting (selective cutting or clear-cutting) for pulpwood or saw timber shall be exemptwithin the RA-200 zoning district. In other zoningdistricts, such activities shall be authorized only inaccordance with the issuance of a Land DisturbingPermit under the requirements of this ordinance.

5.1.4. Removal of Disease or Insect Infestation.Upon the written advice of the County ExtensionService or the Georgia Forestry Commission inaccordance with commonly accepted forestry practicesand a finding of disease or insect infestation, the directormay authorize the removal of trees to prevent thetransmission of disease or infestation, to prevent thedanger of these trees falling, or to prevent potentialinjury to life and property. The owner/developer, prior

to the removal of these trees, shall notify the director,identifying the location of the infested property, and shallsubmit to the director the written finding of the CountyExtension Service or Georgia Forestry Commission.

5.1.5. Tree Thinning.Upon the written advice and findings of the CountyExtension Service or Georgia Forestry Commission, thethinning of trees (selective cutting only) in zoningdistricts other than RA-200, solely for the purpose ofgood forestry management, may be permitted uponauthorization by the Director and shall require thesubmittal and approval of a Tree Preservation and/or

Replacement Plan. Permits authorizing tree thinningshall be limited to the following:

a. The property shall have been initiated forrezoning by Gwinnett County, rather than the propertyowner, from RA-200 to its present zoning classification.

b. The property shall not have been subdivided.The property shall have the same configuration sinceJune 9, 1970 when the comprehensive Zoning Tax Mapswere adopted.

c. A 75 foot undisturbed buffer (not a zoning

buffer) shall be provided and maintained along the entire perimeter of the property, including road frontages,during the land disturbing activity, except for authorizedaccess crossings.

d. The property shall be required to meet a TreeDensity Standard of 24 units per acre upon completion ofauthorized land disturbing activities.


30/98



5.1.6. Zoning Buffer Exclusion.Existing trees proposed to be retained preserved, andnew trees proposed to be planted, in order to meet the buffer requirements of the Zoning Resolution orconditions of zoning, special use or variance approvalshall not be considered in fulfilling the requirements ofthis ordinance.

5.1.7. Easement Exclusion.Properties possessing natural gas, petroleum or electric

power transmission easements, or major sanitary sewermain (greater than 8 inches in diameter) or water main(greater than 16 inches in diameter) distributioneasements, may exclude the land area contained in theeasement from the total acreage of the property infulfilling the Tree Density Standard provided that noimprovements (e.g. parking lots, tennis courts,driveways, storm water detention facilities, etc.) areproposed within the easement. If any improvements are proposed within the easement, then the land area so

utilized within the easement for the improvements, plusan additional 10-feet of land area surrounding theimprovements, shall be used to fulfill the Tree DensityStandard.

5.1.8. Lake and Pond Exclusion.Properties with a lake or pond greater than one (1) acrein size may exclude the land area contained in the lakeor pond from the total acreage of the property infulfilling the Tree Density Standard.

If my site contains an easement,

how do I determine the number of

trees required?

Figure 10. Easement Exclusion

Tree Density Requirements

Four (4) acres - .30 acres buffer -

.2 acres power line easement

4 - (.3+ .2) = 3.5 acres

3.5 acres x 16 TDU/acre = 56 TDU

Easement that contains improvements

must have an additional 10 foot of land

area surrounding improvements.(See Section 5.1.7)

BUFFER :BUFFER :BUFFER :BUFFER :0.300.300.300.30ACRESACRESACRESACRES

PROPOSED BUILDINGPROPOSED BUILDINGPROPOSED BUILDINGPROPOSED BUILDINGPROPOSEDPROPOSEDPROPOSEDPROPOSEDDETENTIONDETENTIONDETENTIONDETENTION

PONDPONDPONDPOND

PROPOSED PARKINGPROPOSED PARKINGPROPOSED PARKINGPROPOSED PARKING

POWEREASEM

ENT

POWEREASEM

ENT

POWEREASEM

ENT

POWEREASEM

ENT

0.200.200.200.20

ACRES

ACRES

ACRES

ACRES

10101010 LANDSCAPED STRIPLANDSCAPED STRIPLANDSCAPED STRIPLANDSCAPED STRIP

StreetStreetStreetStreet

Orange Safety FencingOrange Safety FencingOrange Safety FencingOrange Safety Fencing TOTAL SITE:TOTAL SITE:TOTAL SITE:TOTAL SITE:4444ACRESACRESACRESACRES

R / WR / WR / WR / W


31/98



5.2. Permits.

5.2.1. Land Disturbing Permit Required.Land disturbing activities shall not commence untilsuch activities have been authorized by issuance of anappropriate Land Disturbing Permit under the provisions of the Development Regulations. Once aFinal Plat has been recorded, land disturbing activitieson residential lots shall not occur until a BuildingPermit has been obtained.

5.2.2. Tree Preservation and/or Replacement PlanRequired.For projects not exempt from the provisions of thisordinance, and not included under subsection 5.2.3. or5.2.4. below, a Tree Preservation and/or ReplacementPlan shall be submitted along with the Tree CanopyCalculation, and the other documents required by theDevelopment Regulations for the issuance of aClearing, Clearing and Grubbing, Grading, or

Development Permit.

a. Tree Preservation and/or Replacement Plansincluding the Tree Canopy Calculation, and relateddocumentation shall be reviewed by the departmentfor conformance to the provisions of this ordinancealong with and at the same time as all other plansrequired for a requested Land Disturbing Permit underthe provisions of the Development Regulations.

b. Clearing, grading and development activitiesshall conform in all respects with the approved TreePreservation and/or Replacement Plan. Any revisions

to the proposed development of a property, and anychanges reflected in a subsequently submitted permitapplication, shall be shown on a revised TreePreservation and/or Replacement Plan and beapproved as part of the new or revised permit prior tothe commencement of such changed activities.

5.2.3. Limited Land Disturbing Projects.Projects which propose only limited developmentactivities may be issued a Land Disturbing Permitwithout a Tree Preservation and/or Replacement Planunder the following circumstances:

a. Nonresidential subdivisions shall not berequired to submit a Tree Preservation and/orReplacement Plan if the proposed land disturbingactivities are strictly limited to those directly related tothe provision of the streets and storm water drainageand detention facilities, placement of required soilerosion and sedimentation controls, the installation of public or private utilities, and other requiredimprovements expressly required by the county or by a

Figure 11. Examples of Permit Cards

C. Building Permit

(Yellow Background) Residential

B. DevelopmentPermit

A.LandDisturbancePermit

Clearing,Clearing & Grubbing,or Grading

(Green Background)

(Orange Background)

SAMP

LE


32/98



condition of zoning, special use, modification, waiveror variance approval.

b. Residential recreation areas, and individualmulti-family residential and attached townhomes (noton individual lots), and nonresidential projects (not

involving the subdivision of the property) may beallowed to undertake activities limited to clearing orclearing and grubbing only, without approval of a TreePreservation and/or Replacement Plan, if the proposedland disturbing activities are limited to those portionsof the property outside of all minimum yard areasrequired by the zoning district, all buffer areas required by the Zoning Resolution or conditions of zoning,special use, modification, waiver or variance approval,and any area within the 100-year floodplain, except forcurb cut access into the property and for the placementof required soil erosion and sedimentation controls.Additional areas may be designated by the department

to remain undisturbed as may be reasonably requiredwith consideration given to the proposed use of theproperty, as well as adjacent properties, in accordancewith the County's Land Use Plan. The limits ofclearing or clearing and grubbing shall be establishedno closer to the boundaries of all said undisturbedareas than the driplines of the trees that are locatedwithin said areas.

For any property for which a Tree Preservation and/orReplacement Plan was not required prior to issuance ofa Land Disturbing Permit under the provisions of thissection, all areas required to be undisturbed shall beprovided with protective tree fencing along the limitsof clearing or grading which adjoin existing trees inaccordance with the provisions found in subsection5.4.1. These measures shall be in place prior to beginning clearing or grading activities, and shall bemaintained throughout the land disturbing period.

5.2.4. Residential Lots and Subdivisions.Owners and/or developers of residential lots andsubdivisions shall comply with this article by plantingstreet trees in all residential subdivisions and 2 trees per lot, as a part of providing 16 TDUs per acre.Existing trees shall be counted toward the TDUs.

a. Individual Lot Trees.A minimum of two (2) trees, at least 2 inches indiameter, shall be planted or preserved on eachindividual lot prior to the issuance of a Certificate ofOccupancy. Roots within the drip line area of preserved trees shall remain undisturbed or the treecannot be counted as a required tree. Planted treesshall be a species listed on Appendix "A" Canopy orSmall Tree Species Lists of this ordinance. The

What are the requirements for

trees in single family detached

residential areas?

Two trees per lot * (preserved or

planted), and;

Street trees ** and;

16 Tree Density Units (TDU) per

acre.* Trees may be planted anywhere on

the lot.

** Street trees may be counted toward

meeting the overall site TDUs.

Figure 12. Individual Lot Tree Planting

1. Trees must be a minimum of 2 in size.Preserved tree may be any species and musthave protective fencing for credit.

2. Planted trees must be selected from theTree Species List.

Protective fencingfor preservedtree. 2

Preserved Tree.

2Planted Tree.

Street Trees

Street

Side Walk

R.O.W. Line


33/98



b. Street Trees.Underground utilities are required when planting streettrees. Street tree requirements are as follows:

1. Street trees shall be at least 3 inches indiameter. The quantity of trees shall be one (1) tree per each 50 linear feet of street (both sides of the

street). Trees shall be planted in the street right-of-way. Trees shall be located at least 3 feet from the back of curb unless a modification is granted by thedirector. Street trees listed on Appendix "A" A.2Parking Lot & Street Tree Species List shall beselected, planted and maintained. Maximumallowable genus of street trees to be 33% of entiresubdivision or one genus per street. Street trees counttowards meeting the 16 TDU/ Acre

2. Developers shall enter into a performancesurety agreement with the department guaranteeingtree planting within 2 years of the date of recording of

the Final Plat. The director is authorized to grant amodification from the time limit. The performancesurety shall be provided at the time of recording theFinal Plat. In addition, a Street Tree Planting Planshall be submitted to and approved by the departmentprior to planting by the developer. Street tree plantingshall be delayed from June through August.

3. Street trees shall be maintained and cared for by the property owner adjacent to the tree except insubdivisions in which the property owners association provides maintenance and care. Maintenance shallinclude replacement and trimming as necessary. Amaintenance responsibility statement shall be provided

on the Final Plat. A modification may be granted bythe Director for genus and species substitution forStreet Trees.

c. 16 TDU/ Acre and Tree Protection Areas.Prior to the issuance of a Development Permit, a TreePreservation Plan shall be prepared and approved forresidential subdivisions indicating compliance with theTree Density Standard of 16 Tree Density Units peracre. Preserved trees shall be grouped together in TreeProtection Areas (including driplines or critical rootzones whichever is greater) consisting of at least three(3) trees. Preserved individual 12 inch or greater

diameter trees may also receive credit provided theyare protected by a Tree Protection Area (includingdripline or critical root zone whichever is greater).Planted and preserved trees count toward Tree DensityUnits per Acre.

Figure 13. Street Trees

What is the Street Tree Program ?

Trees must be 3 inches in diameter

(measured at 6 inches from ground level);

Trees are planted 3 feet from curb

within right-of-way;

Planting required along both sides

of new streets;

Number of trees is determined by

linear feet of street (1 per 50 feet)

on each side of the street;

Plan is required that indicates

species, placement, size, and

number of trees; and,

Trees can be spaced for best placement.

Trees must be selected from Parking Lot

and Street Trees Species list.

Planted trees must be nursery stock,

Not dug up from the wild.

From Street to Tree.

6 4

10

3

Side Walk

Property Line-

Grass StripBack of Curb


34/98



5.3. Tree Density Requirements.

5.3.1. Tree Density Standard

On each property for which a Tree Preservation and/or Replacement Plan is required, existing trees shallbe retained and new trees shall be planted such that the

property shall attain or exceed a Tree Density Standardof 16 Tree Density Units per acre, exclusive of anyacreage within a zoning buffer and any trees requiredto be preserved or planted within a zoning buffer andexcept any other land area allowed to be excluded bythis article. Trees, both existing and new, shall bereasonably distributed throughout the site, withemphasis on tree groupings to achieve aesthetic resultsfollowing professional landscaping standards. Treesmay be retained or planted for credit within a publicstreet right-of-way if granted authorization by theDepartment of Transportation.

5.3.2. Tree Density Standard Calculation.

The Tree Density Standard shall be calculatedby summing the following credits and dividing by thetotal acreage of the project included within the limitsof the permit application (but excluding any acreageincluded within a zoning buffer and other land areaallowed to be excluded by this article).

a. Credit for existing trees proposed to bepreserved on the site shall be calculated by multiplyingthe number of trees (by diameter) times the unitsassigned in TABLE B, CREDIT FOR EXISTING

TREES. Credit shall be given all trees preserved on aproperty having a diameter of 3" or more, except treeslocated in a zoning buffer.

b. Credit for new trees proposed to be replacedon the site shall be calculated by multiplying thenumber of trees (by diameter) times the units assignedin TABLE D, CREDIT FOR REPLACEMENTTREES. Credit shall be given for all new treesreplaced on a property except for trees less than 1 inchin diameter and new trees planted in a required zoningbuffer. Multi-trunked trees shall only be given credit by measuring the single largest trunk and not thecumulative total of the various trunks. Tree-formshrubs shall not be given credit for satisfying therequired Tree Density Standard.

c. Credit for specimen trees preserved on thesite shall be calculated by multiplying the number oftrees (by diameter) times the units assigned in TABLEC, CREDIT FOR SPECIMEN TREES. Credit shall begiven for all specimen trees preserved on a propertyexcept for those located in a required zoning buffer

How do I correctly plant a tree?

Figure 14. Correct Planting Method

Note: Proper planning will assure an

adequate supply of trees. Contact a

nursery wholesaler in advance of

beginning your project.

Open burlap at the top of the root ball.Plant a balled and wrapped in burlap treein a hole at least twice the size of itsroot ball. Planted trees must benursery stock.


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where partial credit may be given. A specimen treelocated within a buffer with a critical root zoneextending beyond the buffer is allowed partialcredit toward Tree Density Units. The partial creditis based on the percentage of CRZ that is outsideof the buffer. For example given: a 30" specimentree's CRZ extends by 20% over the buffer line thenthe developer receives 20% of the credit for a 30"existing specimen tree (19.6 x .20 = 3.92 TDU's)."To determine the percentage of CRZ outside of the

buffer simply measure the area of the CRZ circle.Then measure the area of CRZ outside of the buffer.Divide the smaller number into the larger number andthat is your percentage of CRZ. For example: given aspecimen tree's CRZ is 6,000 square feet, 1,200 Sq. Ft.is outside of the buffer. Divide 1,200 by 6,000 andthe answer is .2. In other words, 20% of the CRZ isoutside of the buffer.

d. Additional credits shall be granted under the

following circumstances:(1) For specimen trees see Section 5.6 and Table C.(2) Existing trees to be preserved within a minimum

yard area (as required by the applicable zoningdistrict) or within a 100 year flood plain shall begranted a bonus credit of 50 percent of the unitsassigned in Table B unless the tree is located in azoning buffer.

e. There shall be no more than 33% of any onegenus of tree for overall site. Provide all calculationson plan.

5.3.3 Tree Canopy Calculation.

The Tree Canopy Calculation is required for all newdevelopments and existing developments addingstructural or site improvements as defined in Section5.1.

a. The Tree Canopy shall be calculated byassigning square feet of canopy to each tree proposedand each tree preserved. Square feet of canopy can befound in Appendix A Tree Species Lists. Stands ofthree or more trees can be computed with polygonsand given in terms of square feet. Include buffer trees,

landscape strip trees, parking lot trees and any treepreserved or replaced. Add the total square feet ofcanopy. Take the total site acreage and convert that tosquare feet. Divide the total square feet of canopy intothe total square feet for the site and list it as apercentage. Provide calculations on the TreePreservation/ Replacement plan. There is nominimum or maximum tree canopy percentagerequired at this time.

Tree Canopy Calculation

Example:

Qty Botanical Name

CanopyArea insquare

feet

TotalCanopyarea insquare

feet

10Fraxinuspennsylvanica

1,800 18,000

27Juniperusvirginiana

800 21,600

14Quercuscoccinea

1,800 25,200

8 Nyssa aquatica 800 6,400

23 Pinus taeda 300 6,900

6Existing oakhardwoods

1,800 10,800

Existing(mixture ofsoftwoods andhardwoods)

polygon 23,400

TOTAL 112,300

4.0Acres

Total siteacreage

174,240

Percentage oftotal site canopy

112,300divided

by

174,240

64%

Example of Tree Canopy Calculations


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5.3.4 Tree Bank:

The intent of the Buffer, Landscape, and TreeOrdinance requirements is to ensure that at least aminimum number of trees are replaced and/ or preserved on newly developed or re-developed sites.Only in the event the site tree density or recompensetree requirement cannot be met on site due to hardshipis a Tree Bank an alternative option fulfilled in one oftwo ways.

Trees used to meet requirements for parking lot,landscape strip, Street Frontage Buffer, or bufferreplanting cannot be used towards the Tree Bank.Only trees that are required to meet site density can beused for the Tree Bank.

a. Option 1, Actual Trees: Contribute an equalamount of required trees in the form of actual trees to

the Gwinnett County Tree Bank. If Actual Trees are analternative for the development, then the followingcriteria shall be observed:

1. Submit a site plan, drawn to scale, showing alocation for the planted trees. Provide calculations onthe plan for tree density or recompense trees from thedeveloped site. State the size, genus, species, andquantity of trees to be planted. Each tree must be 2inches in diameter at a minimum.

2. The site for the trees shall be within the samecommission district in which the development is

located.

3. Trees must be Grade A quality based on theAmerican Association of Nurserymen publicationAmerican Standards for Nursery Stock. Trees shallhave straight trunks and dense foliage and be free frominjury, pests, disease or nutritional deficiencies.

4. Trees are to be maintained and guaranteed forone full year after planting by the developer. Anytrees that die during the one year time period must bereplaced by the developer. Standards for transplantingshall be in keeping with those established by the

International Society of Arboriculture, as included inthe "Tree and Shrub Transplanting Manual," latestedition, or similar publications.

b. Option 2, Monetary Compensation for Trees:If Option 1, Actual Trees, is not desirable then theMonetary Compensation for Trees Option is anotheralternative. If the Monetary Compensation for Treesis an alternative for the development, then thefollowing criteria shall be observed:

The Tree Bank is an option if all the

required trees for tree density and / or

recompense cannot be met on site.

OPTION ONE: plant trees on another

site within the same commission district.OPTION TWO: provide monetary

compensation for tree density units that

cannot be met on site.

Directors approval is required prior to

using the Tree Bank.

What Plans are required to submit to

the Director for the Tree Bank

OPTION ONE?

1. Provide a site plan drawn to scale ofproposed site where trees are to be

planted.

2. Show any public utility easements onsite plan.

3. Provide tree density calculations onsite plan of developed site and,

4. State how many tree density unitscannot be met on the developed site.

5. Show locations where trees will beplanted, on the site plan.

6. Obtain property owners signature onroute sheet.

7. State the Commission District ofdeveloped site.

8. State the Commission district ofplanted site.

9. Provide Quality Note on plan Section5.3.3 a (3).

10.Provide a Note of Guarantee for oneyear on site plan Section 5.3.3 a (4).

11.Obtain appropriate signatures on routesheet.


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1. Provide Tree Density calculations on the TreePreservation/ Tree Replacement Plan. Show the totalamount of tree density units that cannot be met on site.

2. Multiply the tree density units that cannot bemet on site by the Monetary Compensation Value. Theproduct of those two numbers shall be provided on theTree Preservation/ Tree Replacement Plan. Contact theCounty Certified Arborist or Staff LandscapeArchitect for the current Monetary CompensationValue.

3. Provide a certified check in the amount of the product given on the Tree Preservation/ TreeReplacement Plan made out to Gwinnett County.Give the certified check to a Development ReviewSection Planner along with a copy of the TreePreservation Tree Replacement Plan.

5.3.4.1 Standards for administering these alternativecompliance methods.

a. The Director must review and approve allrequests for alternative compliance. In no instanceshall the alternative compliance options be used to

comply with any other ordinance requirement than thetree density or specimen tree requirement.

b. The site development permit shall be issuedafter the Director has approved the request for eithercompliance option and received the necessarydocumentation and funds.

What Plans are required to

submit to the Director for the

Tree Bank OPTION TWO?

1. Tree Preservation / TreeReplacement Plan showing:

The tree density units met on

site

The tree density units NOT

met on site

The specimen trees location on

plan

The critical root zone of the

specimen trees

Any calculations for

recompense units for specimen

tree removal.

2. Route Sheet (Application Form)for Directors signature.


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5.4. Tree Preservation and ReplacementRequirements.

5.4.1. The following guidelines and standards shallapply to trees proposed to be preserved for credittoward meeting the minimum required Tree DensityStandard on a property.

a. Tree Protection Areas.

The root system is generally within the dripline orcritical root zone. To protect these critical roots, aTree Protection Area shall be established around eachtree or group of trees to be retained.

(1) The Tree Protection Area shall include noless than the total area beneath the tree canopy asdefined by the dripline or critical root zone of the treeof the tree or group of trees collectively.

(2) Layout of the project site utility and grading plans shall avoid disturbance of the Tree ProtectionArea.

(3) Construction site activities such as parking,materials storage, concrete washout, burnhole placement, etc., shall be arranged so as to preventdisturbances within Tree Protection Areas.

b. Protective Barriers.

(1) Protective tree fencing shall be installedbetween buffers and Tree Protection Areas and areas

proposed to be cleared, graded, or otherwise disturbedon the site, prior to any land disturbance.

(2) All Tree Protection Areas are recommendedto be designated as such with "tree save area signs" posted in addition to the required protective fencing.Signs requesting subcontractor cooperation andcompliance with tree protection standards arerecommended for site entrances.

(3) All Tree Protection Areas must be protectedfrom soil sedimentation intrusion through the use ofsilt screens or other acceptable measures placed up-

slope from the tree protection area.

(4) All protective tree fencing and all erosioncontrol barriers must be installed prior to andmaintained throughout the land disturbing and

Why is the root zone so important?

Most of the trees roots lie in the top

12 inches of soil. Roots of a plant

absorb water, gases, and nutrients

from the soil and atmosphere. Roots

also provide stability and support the

tree.

On a construction site, under-ground

damage to the roots is not easily

noticed. Depending on the type of

damage and species of tree, the

damage may not be obvious for 2-3

years, and death of a tree may not

occur for as long as 7 years.

Figure 15. Tree Roots

NOT TRUE:This artistsconcept regrettablyshows how manypeople envision atrees root system.Most species do noteven have a taproot, and only underrare circumstanceswould roots appearlike this.

MORE LIKELY:Roots spread wheresoil conditions allowaccess to soilnutrients, moistureand sufficient air.This results inabout 85 percent ofa trees roots beingin the top 18 inchesof soil.

Tree roots are not anunderground reflection of the crown.

DripLine-


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construction process, and should not be removed untilfinal landscaping is installed.

c. Encroachment

If encroachment into a Tree Protection Area occurs

which causes irreparable damage to the trees, the TreePreservation and/or Replacement Plan shall be revisedto compensate for the loss. Under no circumstancesshall the developer be relieved of responsibility forcompliance with the provisions of this ordinance, norshall plan revision activities stop the department frominstituting action for violation of this ordinance.

5.4.2. Replacement trees proposed to be planted forcredit toward meeting the minimum required TreeDensity Standard on a property shall comply with thefollowing:

a. The spacing of replacement trees must becompatible with spatial site limitations and withresponsible consideration towards species size whenmature.

b. Trees selected for planting shall be a specieslisted on Appendix "A" Canopy or Small Species Listof this ordinance. Standards for transplanting shall bein keeping with those established by the InternationalSociety of Arboriculture, as included in the "Tree andShrub Transplanting Manual," latest edition, or similar publications. Refer to the American Association of Nurserymen publication "American Standard for Nursery Stock" (ANSI Z60, 1973) for plant materialquality specifications. Refer to the "Manual of WoodyLandscape Plants" (Michael Dirr, 1983, Castle Books)or similar publications for information on tree speciessite requirements.

c. Trees selected for planting must be free frominjury, pests, disease, nutritional disorders or rootdefects, and must be of good vigor, so as to assure areasonable expectation of survivability.

5.5. Tree Species Lists.

Tree species lists are found in Appendix "A" of thisordinance. The director is authorized toadministratively add and delete species to both lists.Except as specifically approved by the director as amodification, only the trees listed shall be given credittowards meeting the requirements of this article.

Why Tunneling Saves Trees

Figure 16

Where can I find more

information?

Figure 17

(And the Gwinnett County Cooperative Extension Service)

Tree species lists for canopy and small

trees are located in the Appendix. The

director or the directors designee can

add or delete sp

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