The Athens-Clarke County (ACC) Community Tree Management Ordinance was adopted in 2005 “with the intent of regulating the quantity, quality and distribution of trees within Athens-Clarke County.” The ACC tree ordinance is comprehensive, and includes both public and private tree management provisions.
In ACC tree canopy cover has been steadily increasing since the adoption of their tree ordinance. Assessments completed in 2001 of 1991 and 2001 tree cover showed a decrease in tree canopy from 53 percent to 49 percent over the 10-year period. In 2005 tree canopy was again measured and remained at 49 percent. Subsequent measurements of tree canopy have shown a steady increase since then. Today Athens-Clarke County’s tree canopy cover is 63 percent! The tree canopy cover goal stated in the tree ordinance is 45 percent.
ACC measures tree canopy cover regularly using GIS and a permanent dot grid placed over the latest aerial photographs of the county. The same dots, in the same locations, are analyzed for each measurement year.
ACC includes in their tree ordinance, by reference, an extensive Athens-Clarke County Tree Species List. ACC has also produced a Field Guide to Community Tree Management Ordinance, which summarizes the ordinance for those working in the field.
TREE ORDINANCE ADMINISTRATION
The ordinance establishes two staff positions to administer and enforce the ordinance, an arborist in the Planning Department and a community forestry coordinator in the Landscape Management Division. The staff responsibilities as described on the County’s website are summarized below.
The Athens-Clarke County Arborist is responsible for the successful implementation of the Community Tree Management Ordinance during the development process. The Arborist reviews tree management plans and notices of timber harvesting, and also inspects properties before, during and after development to ensure that trees are conserved and planted in accordance with the tree ordinance. The Athens Clarke County Arborist’s scope of work includes helping individuals with:
- Creating a Tree Management Plan
- Timber Harvesting
- Tree Removal
- Trees in Environmental Areas
- Tree Programs for Green Schools
ACC Community Forestry Coordinator
Landscape Management Division of the Central Services Department
The Athens-Clarke County Community Forestry Coordinator is responsible for coordinating the Community Tree Program. Components of this program include: management of all trees on Athens-Clarke County streets and properties, administration of the Community Tree Management Ordinance, and providing natural resource related education and outreach to county residents. The Athens-Clarke County Community Forestry Coordinator’s scope of work includes:
- Public Tree Care
- Forest Management
- The Landmark Tree Program
- Neighborhood Forest Assessments
- Utility Pruning Standards
- The Community Tree Council
- Street Tree Ownership and Management
TREE ORDINANCE COMPONENTS
Applicability and Exemptions: The ordinance applies to all real property in Athens-Clarke County. It does exempt single-family residential properties after a certificate of occupancy has been issued, except when substantial improvements are made on those properties and require a development permit.
Tree Board Establishment: The ordinance establishes the Athens-Clarke County Community Tree Council (CTC), with 15 voting members. The CTC meets monthly.
Special Tree Categories: The ordinances defines two categories of special trees. First, protected trees include all public trees, all trees conserved or planted to meet tree ordinance requirements, and all Landmark Trees. While lots in subdivisions are required to have trees as they are built out, the trees on single-family residential lots, after the certificate of occupancy has been issued, are not considered protected trees.
Landmark Trees are trees that have been officially designated as landmarks by the Landscape Management Division. These trees are owner-nominated and must meet one or more criteria for age, size, species, form, character, history, location or association with historic events, persons or landmarks.
Tree Removal Requirements: Tree removal requirements vary based on whether or not there is an approved site plan or tree management plan approved for the site, the size of the lot, the location of the lot, and the number of trees being removed. There is a Tree Removal Review Process flow chart provided on the County’s website to assist individuals in determining whether or not they need approval to remove a tree.
Prior approval for tree removal or a timber harvesting notification is required for:
- Sites with an approved site plan or tree management plan;
- Trees within a Tree Preservation Area (unless they are listed as “do not plant” in the ACC Tree Species List);
- Lots greater than 1 acre in size and removal of more than 5 trees;
- Trees in an overlay district or environmental area; and,
- Trees on the public right-of-way.
Click here to download a copy of ACC’s Timber Harvest Application form.
Tree Density Requirements: ACC utilizes tree canopy cover as their method for requiring tree density on development sites.
New developments, existing developments adding structural or site improvements, developments requiring preliminary plats and developments for which a land disturbance activity permit is required, have to contribute a minimum amount of tree canopy cover. Existing single-family residential lots that appear on a preliminary plat that were approved prior to the adoption of the ordinance are exempt. The percentages of tree canopy cover required are based on the zoning district.
For most zoning districts, the requirements include a minimum amount of conserved tree canopy, with planted tree canopy making up the remainder of the requirement where necessary. Amounts required range from 0% to 60%, depending on the district. The total amount of tree canopy conserved on a site plus that credited to newly planted trees, is divided by the total area of the site to arrive at the percent tree canopy cover for the site.
Planted trees, at the time of planting, are given credit for the future amount of tree canopy cover that can be expected for the species at maturity, under urban conditions, as listed in the tree species list. Large canopy trees (willow oak, for example) are given 1,600 square feet of credit; medium canopy trees (red maple, for example) are given 900 square feet of credit; small canopy trees (dogwoods, for example) are given 400 square feet of credit; and very small canopy trees (crapemyrtles, for example) are given 150 square feet of credit.
Conserved trees are given the greater of their actual tree canopy cover as measured on the ground within the dripline, or the future canopy credit listed in the tree species list. Landmark Trees that are conserved are given twice the standard amount of tree canopy cover credit, either actual or future.
In addition to tree canopy cover, ACC has requirements for street trees in new developments, and trees in parking lots. The trees planted to satisfy street tree and parking lot tree requirements count toward the total tree canopy cover requirements of the site.
Streetscape Trees: Along road frontages, one (1) tree is required for every 30 feet of frontage, and existing healthy trees greater than 2 inches DBH must be incorporated into the streetscape where feasible. The spacing of street trees can be variable, but must average every 30 feet.
Street trees must be planted on private property, within 10 feet of the lot line for medium or large canopy trees, and 5 feet for small canopy trees. With approval of the community forestry coordinator, street trees may be planted on the public street right-of-way.
Parking Lot Trees: A minimum of one (1) canopy tree per seven (7) parking spaces is required. Approved parking lot canopy trees are listed in the tree species list.
Parking lot trees must be planted within 10 feet of the edge of the parking lot pavement, but no closer than 3 feet to the edge of pavement. A parking lot consisting of fewer than ten spaces may incorporate the required parking lot trees around its perimeter.
Adequate rooting area must be provided for large canopy trees planted in interior islands or peninsulas. A single medium canopy tree may be planted in an island or peninsula with minimum dimensions of 9 by 18 feet (the size of a single parking bay), or 2 medium canopy trees may be planted in an area with minimum dimensions of 9 feet by 36 feet (the size of a double parking bay). Conserved trees may qualify for parking lot canopy trees with the approval of the Athens-Clarke County Arborist.
ACC is one of several communities that has required standards for a minimum amount of open soil surface area around a tree planted in a paved area, such as a parking lot. They have requirements for soil quality as well. See “unique features” below for more information on ACC’s soil quantity and quality standards.
Alternative Compliance: ACC has no tree banking provisions or a tree fund for providing alternative compliance options. However, they have a couple of options for creating future forest areas. See “unique features” below for a description of these alternative compliance options.
The ACC tree ordinance includes two unique features–alternative compliance through the establishment of future forest areas and required standards for soil quantity and quality.
For sites that cannot meet the tree conservation requirements, the ordinance allows for the establishment of forest regeneration areas or future forest areas. These alternatives can be used when a site must be completely graded for engineering purposes. In these cases, a percentage of the site equal to the required amount of conserved tree area must be set aside and either planted with seedlings to regenerate a “native” forest, or left open to produce a future native forest through natural regeneration.
Site preparation standards for tree planting include soil quantity and quality specifications. First, a certain amount of open soil surface area must be maintained around each newly planted tree, according to the tree’s expected mature size, as follows:
- Large trees – 400 square feet
- Medium trees – 225 square feet
- Small trees – 150 square feet
- Very small trees – 75 square feet
Secondly, the soil in tree wells, parking lot landscape islands and perimeter planting areas, as well as in all planting sites on a development, must meet the following standards:
- Soil must be well-aerated to a depth of 8 inches, except that in tree planting islands surround by pavement it must be well-aerated to a depth of 18 inches;
- The soil must contain at least 5 percent organic matter;
- The soil pH must be within a range of 5.8 to 7.0.
An approved structural soil mix containing 80 percent rock aggregate, 15 percent mineral soil, and a sticking agent may be used within parking lots and other paved areas to increase the rooting volume available to trees.
Where permeable or porous pavements are used within a parking lot or other paved area the open soil surface area required may be reduced by up to 20 percent.
In addition to the ACC web pages and documents highlighted above, the ACC website provides some additional information to help designers and developers with the implementation of the tree ordinance.
Resources for Designers includes tips for creating a tree management plan, standard notes and detail, and information on calculating critical root zones.
The ACC website also includes a document that outlines the procedures for requesting a variance from the tree ordinance. Click here to view the document.
In 2001, ACC produced a Best Management Practices for Community Trees document that is used in public tree management, but it also serves as a guide for activities required by the tree ordinance.
Published November 2017