Agenda - Council - 09/27/1994 - Laserfiche WebLink

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VI. Tree and $iI¢ Related Disturbances. ~"~ 'x~.),~ ? A. Tree protection zones, specimen trees or stands of trees designated to be saved must be protected from the following damages which may occur during all phases of }and disturbance and construction processes. t. Direct physical root damage. This most frequently occurs during site cleating and grading operations where transport (feeder) roots are cut, torn or removed. 2. Indirect root damage. Most frequently, this results from positive grade changes, temporary storage of fill material, the sedimentation or erosion materials, soil compaction, and soil chemical changes. 3. Trunk and crown disturbance. These disturbances are generally mechanical in nature and are either caused directly by clearing and grading machinery, or indirectly by debris being cleared and falling into trees marked for protection. Soil Contamination Exposure to heat or toxic vapors Exposure to disease vectors 7 VI1. Methods of Tree Pro{ecfion. A. Planning and considerations. Tree space is the most critical factor in tree protection throughout the development process. The root system of trees usually extends beyond the drip line of the tree canopy . The root system within the drip line region is generally considered to be the critical root zone. Disturbance within this zone can directly affect a tree's chances for survival, With reference to root zones, the following standards shall apply: .. 1. The use of tree save islands and stands is encouraged rather than the protection of individual (non-specirnen) trees scattered throu~ghout a site. This wilt facilitate ease in overall site organization as related to tree protection. 2. The protective zone of specimen trees or stands of trees or otherwise designated tree save areas shall include no less than the total area beneath the tree(s) canopy as defined by the farthest canopy drip line of the tree (s). In some instances, the City Forester may require a protective zone in excess of the area defined by the tree's drip line. 3. Layout of the project site utility and grading plans shall accommodate the required tree protective zones. Utilities must be placed along corridors between tree protective zones. Common bury of utilities or tunneling may be recommended. 4. Construction site activities such as parking, material storage, concrete washout, hole placemenl, etc., shall be arranged so as to prevent disturbances within tree protective zones. 5, No disturbance shall occur within the protective zone of the specimen trees or stands of trees without prior approval by the Git5, Forester. 6. Appropriate disease control measures for the protected zone shall be implemented.