2223 TAYLOR DR 2020-06-30 - Laserfiche WebLink

GeoTest Services,Inc. October 24,2014 Jacobson Deck and Garage Improvements,Everett,WA Job No. 14-0554 Erosion Control All clearing and grading activities associated with the proposed improvements will need to incorporate Best Management Practices (BMPs)for erosion control in compliance with current City of Everett codes and standards. All areas disturbed by construction practices should be vegetated or otherwise protected to limit the potential for erosion as soon as practical during and after construction. Areas requiring immediate protection from the effects of erosion should be covered with either plastic, mulch or erosion control netting/blankets. Areas requiring permanent stabilization should be seeded with an approved grass seed mixture, or hydroseeded with an approved seed-mulch-fertilizer mixture. We recommend that appropriate silt fencing be incorporated into the construction plan for erosion control. Limited Tree Removal and Low Growth Vegetation Management GTS observed a large maple in the northwest corner of the property and at the top of the slope that was estimated to be 80 feet tall. The maple was located less than 5 feet from the top-of-slope condition and tree roots were exposed on the slope below the base of the trunk. GTS observed historic evidence of soil erosion and soil creep in close proximity to the tree, extending to both the upper, flat portion of the lawn and on the steep slope. When trees topple or fall on sloping properties, they typical damage other trees and disturb large areas on the slope. It is GTS's opinion that a selective tree topping/tree removal program should be considered for the maple tree above the top-of-slope condition and for those trees on the slope. A tree topping program may improve near- surface slope stability due to the reduction in the size of the tree wind sail and therefore reduction in root wedging of the soil. A selective tree removal program benefits slope stability through the removal of trees that would otherwise topple due to the proximity to the top-of-slope condition or soil loss/erosion, resulting in large uprooted tree trunks that are readily susceptible to erosion and sloughing once the soils are exposed to the elements. Selective tree removal also improves slope stability by removing weight (the tree)from the slope. As part of any vegetation management program, GTS recommends that removed trees be replanted with low-growth vegetation that allows for vegetative cover without significant weight on the slope. An arborist should be contacted to assist with a landscaping plan and be given an opportunity to formulate opinions on which trees are the best candidates for selective topping and/or removal. Where trees are removed, GTS recommends leaving the stump and root system in place. The root structure will continue to provide soil support until new plantings can be established on the slope. Vegetation management efforts on slopes are likely to require a permit to work within geologically hazardous areas. No tree topping or tree removal activities should be performed without approval from the City of Everett and without appropriate mitigation in place at the time of tree topping/removal activities. Vegetation management activites without approval from the City is likely to result in fines, civil penalties, and/or sanctions against the offending party. GTS also recommends that adjacent property owners be informed of any planned activities prior to the start of vegetation management activities. Page 5of.6��