21.72.070 Tree Protection Measures.
A. Tree Protection Measures. To ensure long-term viability of trees and stands identified for protection, permit plans, and construction activities shall comply with the following minimum required tree protection:
1. All minimum required tree protection measures shall be shown on the tree protection and replacement plan.
2. All construction activities, including staging and traffic areas, shall be prohibited within five feet of the drip line of protected trees.
3. Tree protection barriers shall be installed five feet beyond the drip line of significant trees to be protected prior to any land disturbance.
4. Tree protection barriers shall be a minimum of four feet high, constructed of chain link, or polyethylene laminar safety fencing or similar material, subject to approval by the Administrator. On large or multiple-project sites, the Administrator may also require that signs requesting subcontractor cooperation and compliance with tree protection standards be posted at site entrances.
5. Where tree protection areas are remote from areas of land disturbance, and where approved by the Administrator, alternative forms of tree protection may be used in lieu of tree protection barriers, provided that protected trees are completely surrounded with continuous rope or flagging and are accompanied by “Tree Save Area – Keep Out” signs.
B. Preventative Measures. In addition to the above minimum tree protection measures, the applicant shall support tree protection efforts by employing, as appropriate, the following preventative measures, consistent with best management practices for maintaining the health of the tree:
1. Pruning of visible deadwood on trees to be protected or relocated;
2. Application of fertilizer to enhance the vigor of stressed trees;
3. Use of soil amendments and soil aeration in tree protection and planting areas;
5. Ensuring proper water availability during and immediately after construction.
C. Alternative Methods. The Administrator may approve the use of alternative tree protection techniques if a protected tree will be protected to an equal or greater degree than through the techniques listed above.