§ 10-4.363. Tree protection requirements.

(a)

Location of protected trees. All protected trees, including those located outside of the development site, which may be impacted within 75 percent of their critical protection zone or by activity within a distance of three-fourths of the radius of the critical protection zone (measured from the trunk of the tree) by proposed development activities shall be physically located on-site and shown on a site plan submitted as part of the tree removal request in an environmental management permit application. In any portion of the project area where there are groups of trees or large numbers of protected trees, tree protection areas may be designated on the site plan and labeled as an "area not to be disturbed," in lieu of individual tree identification.

(b)

Critical protection zone preservation. During the development activity, all areas surrounding the tree trunk within a minimum of 75 percent of the radius of the critical protection zone of every protected tree not permitted for removal shall be protected from activities that may injure the tree, (such as cut and fill activities, building pad placements, road bed construction, construction material storage, driving or parking of heavy equipment, or trenching, etc.), except:

(1)

Roadway and utility construction shall require protection of a reduced minimum of 60 percent of the radius of the critical protection zone.

(2)

Where adequate mitigation is provided, as determined by the county administrator or designee, for any additional encroachment.

(3)

Where specific analysis is provided by the applicant or when tree characteristics or site conditions, such as previous disturbances, are such to indicate that there is no basis to assume adverse impact as a result of additional encroachment.

(c)

Barriers required. During development, including installation of irrigation systems or any other underground installations, protective barriers shall be placed around each protected tree not permitted for removal to prevent the destruction or damaging of roots, stems or crowns of such trees. The barriers shall remain in place and intact until such time as approved landscape operations begin; however, barriers may be removed temporarily to accommodate construction needs, provided that the manner and purpose for such temporary removal will not harm the tree and is approved by the county administrator or designee. The following are minimum requirements for barrier types:

(1)

Protective posts shall be placed so as to protect all areas within a minimum of 75 percent of the distance from the trunk to the critical protection zone boundary (i.e., three-fourths of the radius of the critical protection zone), for each tree not permitted for removal, except in right-of-way or utility placement areas, where posts shall be placed so as to protect a minimum of 60 percent of the radius of the critical protection zone where approved by the county administrator or designee.

(2)

Posts shall be of nominal two inches by four inches or larger wooden post, two inches outer diameter or larger pipe, or other post material of equivalent size; shall be strung with at least one one-inch by four-inch wooden stringer; and shall be clearly flagged.

(3)

Posts shall be implanted deep enough in the ground to be stable and to extend to a minimum height of four feet above ground.

(4)

Where the county administrator or designee determines that individual protective barriers are not needed in some areas for tree protection, such areas shall instead be clearly staked and flagged with readily visible markers.

(5)

Where development activity is permitted to occur within the radius of the critical protection zone of a protected tree, the county administrator or designee may require a protective girdling of at least the bottom four feet of the tree trunk base along with fencing or other approved techniques.

(d)

Tree protection techniques. Tree protection techniques found in the publication titled "A Technical Guide to Preservation of Trees During Land Development", or its successor, published by the International Society of Arboriculture, or equivalent techniques approved by the county administrator or designee, shall be used and shall be indicated in the environmental management permit application or site plan.

(e)

Tree credit availability. Credit towards tree replanting requirements of subsection 10-4.364(b) may be given for the preservation of an existing tree, provided that the protection criteria set forth in the foregoing subsections are met, and:

(1)

The tree shall not be damaged from skinning, barking, bumping and the like.

(2)

There shall be no evidence of active disease or insect infestation potentially lethal to the tree.

(3)

A minimum of 75 percent of the radius of the critical protection zone of each preserved tree shall be protected during development activities and maintained during and after development in a landscaped or natural state.

(4)

There shall be no impervious area or grade change within 75 percent of the radius of the critical protection zone of the tree.

(5)

Debris and invasive or exotic vegetation shall be removed by hand within 75 percent of the critical protection zone of the tree.

(6)

Tree mitigation techniques. It is the intent of this subsection to preserve mature trees and to promote tree safety. As an incentive to preserve existing trees, when the following arboricultural mitigation techniques are employed in their entirety, the county administrator or designee may defer the tree replacement requirements. No credit will be given and no debits will be charged for successfully mitigated trees. Additional arboricultural mitigation techniques not specified below may be approved when supported with scientific documentation. Documentation supporting proposed mitigation measures shall be submitted with the application for an environmental management permit. The information shall be reviewed and approved by the county administrator or designee. The mitigation plan shall be prepared and administered by the permittee's registered landscape architect or certified arborist. Documentation detailing the mitigation efforts prepared by the landscape architect or certified arborist shall be included in the environmental management plan compliance report prepared in accordance with subsection 10-4.208(b), by the permittee's landscape professional. Reconciliation of the deferred tree replacement requirements shall occur at time of submittal of the compliance report. If the arboricultural mitigation techniques are deemed sufficient by the county administrator or designee, the deferred tree replacement requirements shall be waived. The arboricultural mitigation techniques shall include, but not necessarily be limited to, the following:

(i)

Site monitoring. All tree protection procedures and activities shall be monitored and approved throughout the construction period by a registered landscape architect or certified arborist. Pesticide applications require a state commercial applicators license. Proof of application shall be available upon request to the county's environmental inspector.

(ii)

Watering. All protected trees shall be watered at a minimum rate equivalent to one inch of rainfall per week. Rate shall be dependent upon soil type. For trees that require root pruning, watering shall commence as far in advance as possible, prior to development activity, and shall continue through the completion of the project. Watering shall be adjusted as required by weather conditions. Care shall be taken to prevent water from soaking the base of trees and root collars. Soaker hoses are an acceptable method of irrigation during construction. Installed mechanical irrigation shall be on grade or placed parallel to the radial roots of the tree so as not to damage the trees root system.

(iii)

Mulching. Mulching shall be used throughout the project within the critical protection zone (CPZ) of protected trees to the greatest extent possible. Where construction machinery or vehicular traffic has to pass within the critical protection zone (CPZ), a layer of four to six inches of organic mulch shall be placed within the drive areas within the critical protection zone (CPZ). Additionally a minimum of five-eighths-inch plywood shall be placed over the mulch material positioned where vehicular traffic is proposed. Where possible, within the limits of the project, all critical protection zones (CPZs) of protected and desirable trees should be covered with a two- to three-inch layer of organic mulch or ground cover, as opposed to the placement of sod.

(iv)

Root pruning. Root pruning shall occur as far in advance as possible prior to site grading, earthwork, excavation or any other activity which may damage the roots of a tree proposed for mitigation, in all areas where demolition or new construction requires removal of existing roots (i.e. excavation/construction of footings, retaining walls, curbs, paving and base). Roots shall be cut with a mechanical trenching device to a minimum depth of 18 inches. Where possible, all trenching within the critical protection zone (CPZ) shall be done by hand or an air spade and followed immediately by a clean-cut hand pruning of all roots greater than three-fourths-inch diameter. Where it is not possible to hand trench, mechanical trenching may be approved by the city's environmental inspector. All pruned/cut roots shall be covered as soon as possible with topsoil, mulch, or other organic medium. Any root-pruning areas that cannot be protected by immediate backfill replacement shall be covered with burlap and wetted to retard soil/root dehydration. The cutting of all major support roots or roots greater than six inches diameter or within ten feet of the trunk collar, shall be reviewed in the field by the county's environmental inspector, a landscape architect or a certified arborist. This inspection shall determine if a tree designated to remain, may have to be removed due to the size of the cut and the possibility of the tree becoming a future liability.

(v)

Fertilization. Prescribed fertilization, if indicated through soil analysis, shall occur as far in advance of root pruning as possible (six to 12 months is most desirable). Commercial fertilizer applications shall be in accordance with the requirements of chapter 10, article XIV of the Land Development Code regarding fertilizer use, and performed by an individual holding a county approved best management practice training certificate.

(vi)

Soil aeration. Where soil compaction has occurred within the critical protection zone (CPZ) of protected and desirable trees on site, an aeration method, approved by the county administrator or designee or a certified arborist shall be required. The soil aerating method used shall be applied to a depth no less than eight to ten inches, below original grade and spaced no greater than 24-inches, staggered spacing. Based on soil analysis and compaction, it may be necessary to recommended that a high nitrogen (3-1-1 ratio) slow release fertilizer mixed with peat moss and gypsum or peat moss and sand (1-5-2 ratio) mix be back filled into the aeration holes. Commercial fertilizer applications shall be in accordance with the requirements of chapter 10, article XIV of the Land Development Code regarding fertilizer use, and performed by an individual holding a county approved best management practice training certificate.

(vii)

Pruning. Pruning and crown clearing shall be performed by a certified arborist in accordance with the currently adopted ANSI A300 Standards. Pruning and crown cleaning shall consist of the removal of all dead and diseased limbs as well as heavy concentrations of moss and vines that compete with crown foliage. Branch collar cuts over eight-inch diameter should be avoided but may be allowed to raise limbs in order to accommodate construction traffic, equipment and structures, as advised by a certified arborist.

(f)

Understory protection in canopy road tree protection zones. No underbrushing or other removal of understory vegetation shall be allowed within the canopy road tree protection zones, except when approved for legal access (provided no alternative exists) or for health, safety, or welfare of the public as specified in a vegetation management plan, submitted to and approved by the county administrator or designee, which outlines specific planting and maintenance operations designed to restore or maintain the natural vegetation component of a specific canopy road section. Each vegetation management plan shall be consistent with the objectives and intent of this article. Poisonous or noxious species shall be exempt from the requirements of this article. They shall be kudzu (Pueraria lobata), Chinese tallow (Sapium seberiferum), Silktree/Mimosa (Albizia julibrissin), chinaberry (Melia azedarach), Coral ardisia (Ardisia crenata), Heavenly bamboo (Nandina domestica), poison ivy/oak (Toxicodendron radicans/toxicarium), grape vine (Vitis spp.), Cherokee rose (Rosa laevigata), greenbrier (Smilax spp.), Virginia creeper (Parthenocissus quinquefolia) and any plant listed on Leon County's List of Invasive Exotic Plants. As a condition of the approval of a vegetation management plan, a satisfactory plan shall be presented by the applicant for the successful replacement of understory vegetation equal to the square footage of the area cleared. If protected understory vegetation is removed without an approved vegetation management plan or otherwise in violation of this chapter, the square footage of the required replant may be increased up to twice the size of the vegetation removal area at the discretion of the county administrator or designee. All removal and replanting shall be in conformance with the Canopy Roads Management Plan. In cases where the applicant can show that an area was maintained by mowing, pruning or other techniques on a regular basis, prior to January 15, 1990, such person may obtain approval of a vegetation management plan that may include continued maintenance of such existing lawn and shrubbery by submitting a letter of request to the county administrator or designee which includes a verified statement and description of the area to be subject to such a plan and the history of maintenance upon which the request is based. Minimal public road safety maintenance practices which must occur within canopy road tree protection zones shall not require a vegetation management plan if carried out pursuant to an approved general permit. Leon County is responsible for maintenance practices in the canopy road tree protection zones on county-maintained roads up to the right-of-way line. Private property owners are responsible for maintenance practices outside the right-of-way line.

(g)

Governmental approval. No development shall occur within 100 feet of the centerline of a canopy road without the express approval of the local government.

(Ord. No. 07-20, § 2, 7-10-07; Ord. No. 12-07, § 9, 5-8-12; Ord. No. 17-10 , § 4, 6-20-17)