Division 51A-10.100. In General.


In this article

(1) AGE CLASS means a distinct group of trees originating from a single natural event or regeneration activity (i.e., a 10-year age class), as used in inventory management.

(2) ANSI A300 means the American National Standard for Tree Care Operations, including all parts, as amended.

(3) APPROVED TREE LIST means the list of replacement and landscape trees approved by the director.

(4) ARTIFICIAL LOT means an area within the building site that is delineated by the building official or the director of park and recreation for the sole purpose of satisfying the requirements of this article (see Section 51A-10.122)


(A) a tree growing on a property boundary line between two private lots resulting in joint ownership by the adjacent property owners when the trunk exists on each property; o

(B) a tree that has 20 percent or more of its tree canopy cover extending over a property line into an adjacent building site.

(6) BROWNFIELD means a building site, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant

(7) CALIPER means the thickness of a tree trunk measured in inches. (Refer to 10.105)

(8) CANOPY TREE means a species of tree that normally bears crown foliage no lower than six feet above ground level upon maturity.

(9) CLASS 1 TREE means a tree located in a primary natural area or a geologically similar area within 50 feet above the escarpment zone.

(10) CLASS 2 TREE means a tree that is not otherwise classified as a Class 1 tree or Class 3 tree.

(11) CLASS 3 TREE means Arizona ash, black willow, cottonwood, hackberry, honeylocust, mesquite, mimosa, mulberry, ornamentals, pinus spp., Siberian elm, silver maple, sugarberry, or a small tree.

(12) CLEARING means any activity that removes or seriously injures one or more trees or the vegetative ground cover of one or more trees, such as root mat removal or topsoil removal

(13) COVERED SOIL AREA means an area of soil that is under nonpermeable pavement and is designed to accommodate tree root growth.

(14) CRITICAL ROOT ZONE means the circular area of ground surrounding a tree extending a distance of one foot per diameter inch of the tree, measured from the tree trunk or stem

(15) DEVELOPMENT IMPACT AREA means the area of land or vegetation alteration within a property including, but not limited to, clearing, grading, excavating, filling, and any construction site operations, paving, or any other installation

(16) DIAMETER means the thickness of a tree trunk (Refer to 10.105)

(17) DRIP LINE means a vertical line that runs from the outermost point of the crown of a tree to the ground.

(18) ENHANCED PAVEMENT means any permeable or nonpermeable decorative pavement material intended for pedestrian or vehicular use approved by the director. Examples of enhanced pavement include, but are not limited to, brick or stone pavers, grass paver, exposed aggregate concrete, and stamped and stained concrete.

(19) EVERGREEN TREE OR SHRUB means a tree or shrub of a species that normally retains its leaves throughout the year.

(20) FACADE PLANTING AREA means the portion of a lot abutting a storefront, office, or mixed-use building facade.

(21) FLOOD PLAIN means any land area susceptible to inundation by the hundred-year frequency flood.

(22) FOREST STAND DELINEATION (“FSD”) means a comprehensive assessment of the conditions of a property using multiple types of information, including, but not limited to, a tree survey, aerial imagery collected from private or public sources, natural resources assessments, topographic maps, management plans, a map of conservation areas, land use maps, etc., to provide the required data to determine tree replacement requirements and forest conservation objectives. (REVIEW: Helpful Resources - Step-by-Step Guide to Taking Urban Forest Inventory Measurements; FIREMON Tree Data Sampling)

(23) GRADING means any digging, scooping, removing, depositing or stockpiling, of earth materials.

(24) GREEN INFRASTRUCTURE means the ecological framework of trees and vegetation used in conjunction with engineered systems for the effective and resilient processes of stormwater management, climate adaptation, urban heat abatement, biodiversity, improved air quality, clean water, and healthy soils, for sustainable social, health, and economic benefits of the urban community.

(25) GROUND COVER means natural mulch, or plants of species that normally reach a height of less than three feet upon maturity, installed in such a manner so as to form a continuous cover over the ground.

(26) HABITAT PRESERVATION AND RESTORATION AREA means a designated area on a landscape plan dedicated to the restoration and preservation of an undeveloped site through active or passive management practices.

(27) HISTORIC TREE means a tree, or grove of trees, that has been recognized by resolution of the city council as having cultural or historical significance.

(28) HUNDRED-YEAR FREQUENCY FLOOD means the flood having a one percent chance of being equaled or exceeded in any given year. This flood is based upon the drainage area being fully developed to current zoning limitations

(29) INTERIOR ZONE means the area of a lot not included in a street buffer zone or a residential buffer zone

(30) INVASIVE PLANT means a plant that has been classified as invasive to the Dallas region by Texas Parks and Wildlife or the Texas Department of Agriculture.

(31) LANDSCAPE ARCHITECT means a person licensed to use the title of "landscape architect" in the State of Texas in accordance with state law.

(32) LANDSCAPE AREA means an open soil area covered by natural grass, ground cover, stone aggregate or river rock, or other plant materials for the purpose of landscaping or the growth and establishment of trees and other vegetation.

(33) LANDSCAPE BUFFER STRIP means a landscape area that serves a buffer function.

(34) LARGE SHRUB means a shrub that normally reaches a height of six feet or more upon maturity.

(35) LARGE TREE means a tree species that typically attains a height and canopy width of at least 50 feet at maturity, or as classified by the director

(36) LEGACY TREE means a large or medium tree planted in a landscape area in accordance with Section 51A-10.104 and Section 51A-10.135.

(37) LOT means:

(A) a "lot" as defined in Section 51A-2.102; and

(B) an "artificial lot" as defined in this section.

(38) LOT WITH RESIDENTIAL ADJACENCY means any of the following:

(A) A building site containing a multifamily use that is adjacent to or directly across:

(i) a street 64 feet or less in width; or

(ii) an alley;

from private property in a single family, duplex, townhouse, CH, or RTN district or a residential planned development district.

(B) A building site containing a nonresidential use that is adjacent to or directly across:

(i) a street 64 feet or less in width; or

(ii) an alley;

from private property in an agricultural, single family, duplex, townhouse, CH, multifamily, manufactured housing, or RTN district, or a residential planned development district.

(C) An artificial lot containing a multifamily use if the lot is less than 200 feet from private property in a single family, duplex, townhouse, CH, or RTN district, or a residential planned development district.

(D) An artificial lot containing a nonresidential use if the lot is less than 200 feet from private property in an agricultural, single family, duplex, townhouse, CH, multifamily, manufactured housing, or RTN district, or a residential planned development district

(39) MEDIUM TREE means a tree that typically attains a canopy height of at least 30 feet and a width between 15 feet and 50 feet in width at maturity, or as otherwise classified by the director.

(40) NONPERMEABLE COVERAGE means coverage with any pavement that is not "permeable pavement” as defined in this section.

(41) NURSERY STOCK means a plant grown in or obtained from a nursery

(42) OPEN SOIL AREA means an unpaved area of soil.

(43) PEDESTRIAN PATHWAY means an area intended for use by pedestrians or non-motorized vehicles that is physically or visually distinguishable from parking and driving surfaces by concrete curbs, wheel stops, or other permanent barriers, landscape barriers, or a change in surface materials such as pavers, patterned concrete, or flagstones.

(44) PERMEABLE PAVEMENT means director approved paving systems, pavers, or other structural surfaces that allow stormwater infiltration.

(45) PREVIOUSLY DEVELOPED SITE means a building site that has been substantially altered through paving, construction, or other activity that requires or required permitting or licensing through a regulatory agency.

(46) PRIMARY NATURAL AREA means an ecologically sensitive area including 100-year flood plain and riparian areas, wetlands or 50-foot wetland buffer, perennial and intermittent streams measured to 50 feet above top of bank, and the escarpment zone.

EPA:(Seasonal streams (intermittent) flow during certain times of the year when smaller upstream waters are flowing and when groundwater provides enough water for stream flow. Runoff from rainfall or other precipitation supplements the flow of a seasonal stream. During dry periods, seasonal streams may not have flowing surface water. Larger seasonal streams are more common in dry areas.)

(47) PRIVATE PROPERTY means any property not dedicated to public use, except that "private property" does not include the following:

(A) A private street or alley.

(B) Property on which a utility and public service use listed in Section 51A-4.212 is being conducted as a main use.

(C) A railroad right-of-way.

(D) A cemetery or mausoleum.

(48) PROTECTED TREE means:

(A) a tree of any species that has a minimum diameter of eight inches that is not classified as unprotected in this article;

(B) any tree in a stand which projects a tree canopy over a building site when identified within a forest stand delineation review; or

(C) a tree that was planted as a replacement tree.

(49) REMOVE OR SERIOUSLY INJURE means an intentional or negligent action that will more likely than not cause a tree to decline and die within five years of the act. Actions that constitute removing or seriously injuring a tree include, but are not limited to: cutting down a tree; excessively pruning or topping a tree; compacting the soil above the root system of a tree; changing the natural grade above the root system of a tree; damaging the root system or the trunk of a tree (such as by operating machinery near, or by clearing or grading the area around, the trunk of a tree); failing to repair an injury to a tree from fire or other causes, which results in or permits tree infections or pest infestations into or on the tree; applying herbicidal or other lethal chemicals; and placing nonpermeable pavement over the root system of a tree.

(50) RESPONSIBLE PARTY means the property owner and any other person or entity responsible for removing or seriously injuring a protected tree.

(51) REPLACEMENT TREE means a tree that is planted in accordance with Section 51A-10.134.

(52) ROOT PATH means a path constructed using aeration or drainage strips providing roots a route under pavement from a tree to an adjacent landscape area.

(53) SCREENING means screening that complies with Section 51A-4.602, except as those regulations may be expressly modified in this article.

(54) SECONDARY NATURAL AREA means undisturbed areas on a building site other than primary natural areas.

(55) SIGNIFICANT TREE means a protected healthy tree whose age, size, unique type, or natural or historical character are of special importance to the city, and meets the following species and size requirements:

(A) Post oaks with a minimum diameter of 12 inches.

(B) Trees of the following species having a minimum 24-inch diameter: American elm, bois d’arc, cedar elm, chittamwood, common persimmon*, eastern red cedar, green ash, all other oaks, pecan, all walnut species, and white ash.

*Common persimmon, aka American persimmon (Diospyros virginiana). Chittamwood, aka gum bumelia (Bumelia lanuginosa).

(56) SMALL TREE means a tree that typically attains a maximum height of 30 feet at maturity or is classified as a small tree by the director.

(57) SOIL means a medium that plants will grow in.

(58) STAND means a group of trees or other growth occupying a specific area that is sufficiently similar in species composition, size, age, arrangement, and condition, to be distinguishable from adjacent forest.

(59) SUSTAINABLE DEVELOPMENT INCENTIVE (“SDI”) means a method of compliance that applies sustainable development, tree preservation practices, and tree mitigation reductions.

(60) TOPPING means the reduction of tree size using internodal cuts without regard to tree health or structural integrity.

(61) TREE CANOPY COVER means the amount of ground area directly beneath a tree’s crown to the drip line or the combined crowns of a stand of trees, measured in square feet.

(62) TREE REMOVAL PROPERTY means the lot, parcel, right-of-way, or tract of land where a protected tree will be or has been removed or seriously injured.

(63) TREE SURVEY means a report that meets all of the requirements for a tree survey in Section 51A-10.132.

(64) UNPROTECTED TREE means the following:

(A) Callery pear (all cultivars)

(B) Chinaberry.

(C) Chinese tallow.

(D) Ilex species (except for yaupon holly and Possumhaw holly.)

(E) Palm (all plants in Palmae).

(F) Tree-of-heaven or Ailanthus.

(G) Other trees listed as invasive plants.

(H) Trees with a diameter of less than 10 inches at the point on the trunk 4.5 feet above the ground, located on a lot with an existing single family or duplex use that is occupied at the time of removal.

((H) - Item-derived from 2017 Texas State legislation to address protected trees on homeowner lots.)

(65) UNRESTRICTED ZONE means the area on a lot where tree mitigation is not required. (Refer to 10.134(b)).

(66) URBAN STREETSCAPE means the pedestrian-oriented street environment between the back of curb and building facade for frontages that have a required front yard of 15 feet or less in depth. (Refer to 10.125(b)(1)).

(67) WATER COURSE means a natural or constructed channel for the flow of water.