20 ATTACHMENT 3 - Laserfiche WebLink

Updated Arborist Report Sarvana Chilla, 3987 Stanley HortScience I Bartlett Consulting Page 8 Tree Preservation Guidelines The goal of tree preservation is not merely tree survival during development but maintenance of tree health and beauty for many years. Trees retained on sites that are either subject to extensive injury during construction or are inadequately maintained become a liability rather than an asset. The response of individual trees depends on the amount of excavation and grading, care with which demolition is undertaken, and construction methods. Coordinating any construction activity inside the TREE PROTEcrioN ZONE can minimize these impacts. The following recommendations will help reduce impacts to trees from development and maintain and improve their health and vitality through the clearing, grading and construction phases. Tree Protection Prior to and During Demolition 1. The construction superintendent demolition contractor shall meet with the Project Arborist before beginning work to discuss work procedures and tree protection. 2. For design purposes, the TREE PROTECTION ZONE for this project is defined as the dripline of any tree to be preserved. Any demolition and construction activity within this zone must be monitored by the Project Arborist. 3. In those areas close to construction including trees #11 - 15, install trunk protection devices such as winding silt sock wattling (see photo at right) or wood planks around trunks or stacking hay bales around tree trunks to the height of the lowest branch. Any low branches that are within the work zone also should be protected. Hay bales shall surround the tree as well as cover any surface roots greater than 3" diameter. 4. Maintain the existing irrigation system. If the existing irrigation system is not functional, have a temporary system installed (using soaker hoses or pvc laid on the ground and covered with mulch) as soon as possible to supply trees with water to help recovery and prepare it for impacts associated with the demolition and construction process. 5. Prune trees to be preserved to clean the crown of dead branches 1" and larger in diameter, raise canopy of tree #1, 10, 16 and 18 if needed for construction traffic as approved by the Project Arborist. Branches extending into the work area that can remain following demolition shall be tied back and protected from damage. All pruning shall be done by a State of California Licensed Tree Contractor (C61/D49) and Certified Arborist or Certified Tree Worker. Pruning shall be in accordance with the Best Management Practices for Pruning (International Society of Arboriculture, 2002) and adhere to the most recent editions of the American National Standard for Tree Care Operations (2133.1) and Pruning (A300). 6. Trees to be removed shall be felled so as to fall away from TREE PROTECTION ZONE of trees to remain and avoid pulling and breaking of roots of trees to remain. If roots are entwined, the Project Arborist may require first severing the major woody root mass before extracting the trees, or grinding the stump below ground. 7. Structures and underground features to be removed within the 10' of a tree shall use equipment that will minimize damage to trees above and below ground, and operate from outside the Tree Protection Zone. Tie back branches and wrap with protective materials to protect from injury as directed by the Project Arborist. The Project Arborist shall be on- site during all operations within the Tree Protection Zone to monitor demolition activity.