Miami Beach Tree Preservation and Protection Requirements

(1) Tree protection requirements, in general and during construction. (a) General. All reasonable steps shall be taken to prevent the destruction or damaging of trees for which no tree work permit has been issued during site development and construction on private or public property. Any owner, tenant, contractor or agent thereof who fails to provide tree protection, as set forth herein, shall be subject to enforcement as provided in section 46-67. Trees destroyed or incurring major damage must be replaced by trees of equal environmental value, as specified by the environment and sustainability department, prior to the issuance of the certificate of occupancy or certificate of use, unless removal of the trees has been authorized pursuant to a tree work permit. Tree protection zones must be established for all trees that remain in place on-site and for any trees relocated within or to the site. When proposed development activities may damage the root systems or canopies of trees to be retained or relocated on-site, alternatives to the proposed activities or effective protective measures, shall be identified and used. (b ) Permit/construction drawings. All permit and construction drawings of the site shall show the tree protection zones, as prescribed by the environment and sustainability department, as shaded areas that are accurately drawn to scale and labeled as such on the drawings. The tree protection zones shall be shown on all drawings that include any underground utility installations, including, but not limited to, irrigation, plumbing, electrical, telecommunication or streetlight lines. The tree protection zones shall be shown on all drawings that include structural installations that will require excavation (s) , and for above-ground installations that may include, but is not limited to, such as walkways, street lights, overhead wires or other types of infrastructure. (2) Tree protection specifications. The following tree protection specifications must be adhered to, in general, and as a condition of approval of the site plan for any project. The environment and sustainability department may require supplemental protection measures to ensure the protection of trees. The environment and sustainability director and his/her designee shall have the authority to enter the subject property to ensure compliance with required tree protection measures. (a) Protective barriers. (i) Placement. Protective barriers shall be placed at the drip line of each tree, cluster of trees, or preservation area, and in no case less than ten feet from the trunk of any protected tree, tree cluster or preservation area. In situations where trees have been transplanted to the project site, the protective fencing shall be placed no closer to the tree than a point one to two feet outside the root ball, or at the drip line, whichever is greater. The fenced tree protection zones shall be extended where necessary to protect tree canopies roots. If trees are to be preserved in place and root pruning is required to accommodate new construction, the root pruning locations shall be identified and approved by the environment and sustainability department, and fencing shall be installed one to two feet beyond the edge of the root ball. The installation of the fencing shall be coordinated with any phased root pruning that must occur. Tree maintenance measures must defined in the general notes of the approved construction plans or a report from an ISA Certified Arborist and or ASCA Registered Consulting Arborist prior to any root pruning or transplanting. (ii) Timing and duration. All protective barriers shall be installed prior to the start of any construction or site development, including tree removal, demolition or land-clearing activities, and shall remain in place throughout all phases of construction. Protective barriers shall be maintained in place until development is completed, and shall not be removed until the environment and sustainability department inspects the site and authorizes their removal. (iii) Barrier specifications. Sturdy temporary barriers shall be installed around all tree protection zones. Barriers shall be a minimum of four feet high, and shall be constructed of continuous chain link fence with metal posts at eight-foot spacing, or of two-by-four-inch posts with three equally spaced two-by-four-inch rails. Posts may be shifted to avoid roots. (b) Activities within tree protection zones enclosed by protective barriers. (i) Understory plants within areas surrounded by protective barriers shall be protected. (ii) No oil, fill, equipment, building materials, building debris, or any other material shall be placed within the areas surrounded by protective barriers. (iii) No disposal of any waste material such as paints, oils, solvents, asphalt, concrete, mortar, or any other material shall occur within the areas surrounded by protective barriers. (iv) Natural grade shall be maintained on areas surrounded by protective barriers. In the event that the natural grade of the site is changed as a result of site development such that the safety of the tree may be endangered, tree wells or retaining walls are required. (v) Only hand digging and grading activities will be permitted within the tree protection zone. All surrounding areas must be graded to a point that meets the outside of the tree protection zone. (vi) Underground utility lines, including, but not limited to, irrigation, plumbing, electrical, or telecommunication lines, shall be placed outside the areas enclosed by protective barriers. If such placement is not possible, disturbance and root damage shall be minimized by using techniques such as tunneling, hand digging, excavation with an air spade, or the use of overhead utility lines. (vii) No vehicles or equipment shall be permitted within areas surrounded by protective barriers. (c) Construction of fences, walkways and walls. Fences, walkways and walls shall be constructed to avoid disturbance to any tree to remain in place onsite in the vicinity of construction activities. Post holes and trenches located close to trees shall be dug by hand and adjusted as necessary, using techniques to avoid damage to major roots system. (d) Attachments prohibited. No attachments, signs, chains, ropes, or wires other than those of a protective or non-damaging nature shall be attached to any trees on publicly owned or controlled property, in general, or during any proposed site development or construction. (3) Root cutting. The cutting of roots with a diameter of two inches or larger is prohibited, unless there is no feasible alternative, as determined by the environment and sustainability director or his/her designee. The city may require that construction activities, such as trench lines and walkway construction, be redirected away from tree root zones. Root cutting shall be done according to approved techniques as outlined herein: (a) Trees shall be evaluated by the environment and sustainability director to determine whether the root cutting will destabilize the tree or cause unacceptable damage to the tree. (b) Root cuts shall be made, at minimum, a distance from the trunk equivalent to three times the tree’s trunk diameter at four and one-half feet above ground unless unavoidable because of sidewalks, pavement, or other infrastructure. Root cuts must be made at a distance from the trunk equivalent to five times the tree’s DBH or greater in all other circumstances. (c) Roots may not be torn off with power equipment, and cut roots shall not be left with ripped, ragged or shredded ends. Roots must be cleanly severed with sharp hand tools or power root saws. (d) When tunneling or otherwise avoiding roots is not possible, the trench shall be carefully excavated by hand or machine and, when a root with a diameter of two inches or greater is encountered, a final clean cut shall be made with a saw. The cut shall be made flush with the side of the trench closest to the tree. The root pruning trench shall be backfilled with soil. (e) When adjacent to new curbing, uncurbed paved areas, or areas of grade changes, roots shall be cut no more than 18 inches towards the tree from the back of the curb, the edge of the pavement, or the point of intersection of old and new grades, respectively. After root pruning, no excavation for the installation of forms or for any other reason may be performed any closer than six inches outside of the root pruning cut. The root pruning trench shall be backfilled with soil. (4) Tree relocations. (a) Irrigation must be present and applied effectively for two to four weeks prior to root pruning, through the period of root pruning, and after root pruning and transplantation until the tree has been completely reestablished at the new planting space. Irrigation shall be operated automatically with water being applied directly to and just outside of the remaining intact root system. Watering frequency shall be such so as to insure that free water is available to the root system at all times. Any temporary disruption in automatic operation shall be supplemented by hand watering. (b) There should be no canopy pruning or a minimum of canopy pruning before or after root pruning. Dead, diseased or damaged branches shall be pruned at this time. (c) The root system of a tree to be relocated shall be well-watered before the tree is dug and lifted to ensure that the tree is properly hydrated, and to improve cohesiveness of the root ball. (d) All transplanting and relocating of trees or palms shall be done in compliance with standards set forth in the most recently published edition of the American National Standards Institute ANSI A-300 Standards. This requirement includes all procedures, techniques, standards for minimum root ball size, and any other standards included in ANSI A-300 Standards. (e) Relocated trees shall be braced in such a fashion as to not scar penetrate perforate or otherwise inflict damage to the tree. (5) Tree pruning. (a) Tree pruning is to be performed in accordance with ANSI A-300 Standards and good horticultural practices. Hatracking, girdling spiking or any other pruning activities that effectively destroy a tree (s) are prohibited. The city may require that construction activities minimize negative impacts to tree canopy. (b) Any tree service performing palm or tree pruning activities not solely limited to removal of dead palm fronds on private or public property within the city must have an individual present onsite to perform or oversee the work who is either an ISA certified arborist or an ASCA registered consulting arborist in good standing. (c) Trees shall be pruned in the following manner: (i) All cuts shall be clean, flush and at junctions, laterals or crotches. Cuts shall be made as close as possible to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub. Tree limb reduction cuts shall be the preferred option with tree limb removal cuts preformed only as a last resort. (ii) Removal of dead wood, cross branches, branches with poor angles of attachment and thinning of suckers shall be accomplished simultaneously without any reduction in crown. (iii) Pruning of lateral branches that results in the removal of more than one-third of all branches on one side of a tree shall not be permissible unless allowed per subsection 46-62 (5) (c) . (iv) Lifting of branches or tree thinning shall be designed to distribute over half of the tree mass in the lower two-thirds of the tree. (v) No more than 25 percent of a tree’s living canopy shall be removed within a one-year period. (vi) Tree canopy removal of greater than 25 percent may only be considered under the following criteria as outlined herein:a.The tree is located in the proposed building footprint area or yard area where a structure or improvement shall be placed and unreasonably frontage (within the city’s required setback) , shall not be considered to be located within the building footprint or yard. Trees on the public right-of-way shall not be considered for removal of more than 25 percent of a tree’s canopy as a result of restriction to or from ingress or egress to the garages or parking on the site, provided however, that if there is no other reasonable access to and from the structure or to the property from the public right-of-way, as determined by the environment and sustainability director and his/her designee the urban forester. Authorization to remove more than 25 percent of a tree’s canopy including right-of-way trees must be received prior to issuance of a building permit.b.The tree is diseased or damaged; creates hazardous conditions; interferes with utility service; creates unsafe vision clearance; or materially impairs the structural integrity of an existing structure.c.If tree pruning is required to facilitate a construction project, the environment and sustainability department may require that the property owner provide a written report from an ISA certified arborist and/or ASCA registered consulting arborist before making any determinations in conjunction with this section. The environment and sustainability department may also require monitoring by an ISA certified arborist and/or ASCA registered consulting arborist during construction to assure proper tree pruning practices are implemented. (6) Tree maintenance. The maintenance of right-of-way trees and palms shall be the responsibility of the adjacent property owner to maintain in accordance of subsection (5) . (7) Exceptions. Exceptions to the requirements of subsections (1) and/or (2) and/or (3) of this section shall be approved only when the property owner receives specific written authorization from the environment and sustainability director or his/her designee. The environment and sustainability director or his/her designee shall not issue written approval, unless he/she determines that the affected trees can be adequately protected and maintained without meeting the requirements of these subsections, or that, due to exceptional circumstances, it is not practical or reasonable to meet the requirements of this section.