Agenda - Parks and Recreation Commission - 09/08/1994

Home

A. Planning and considerations. Tree space is the most critical factor in tree protection throughout the development process. The root system of trees can easily extend 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-specimen) trees scattered throughout a site. This will 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. 4. Construction site activities such as parking, material storage, concrete washout, hole placement, 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 City Forester. 6. Appropriate disease control measures for the protected zone shall be implemented. ....... B. Protective Barriers. 1. Active protective tree fencing shall be installed along the outer edge of and completely surrounding the critical root zones of ali specimen trees or stands of trees, or otherwise designated tree protective zones, prior to any building construction. 2. These fences will be a minimum four (4') feet high. Four (4') feet orange polyethelyne laminar safety fencing is preferred. Twine or safety ribbon are not allowed. 3. Passive forms of tree protection may be utilized to delineate tree save areas which are remote from areas of land disturbance. These areas must be completely surrounded with continuous rope or flagging (heavy mil - minimum four [4"] inches wide). All passive tree protection must be accompanied by "Keep Out" or "Tree Save" signage 4. All tree protection zones should be dekign, ated as such with "Tree Save Area" signs posted visibly on all sides of the fenced area.~ These signs are intended to inform subcontractors of the tree protection process. Signs requesting subcontractor cooperation and compliance with tree protection standards may be required for site entrances.