Laserfiche WebLink
climbs at a 10+% grade and makes a through cut where the Baker property adjoins it. <br />The slopes of this cut range from almost solid rock to loose scree (talus). The cut slopes <br />had been laid back where the scree is present. The slopes appeared stable and at an angle <br />of repose. This is indicated by a scattering of clumps of grasses and forbs found on some <br />portions of the slope. At a few spots, the cuts have sloughed exposing the natural surface <br />and roots from existing trees located at the edge of the cut. <br />Survey stakes indicate the road right-of--way crosses the cut slope approximately midway. <br />Problem and Causal Agent: <br />At the northern end of the property (Lot 42) and just south of a draw, I was told, and <br />could observe, material (scree) had been excavated from the cut bank. The removal of <br />this material caused the slope to become unstable and exceed the angle of repose. Once <br />material was removed, scree above the borrow area sloughed down. The result of this <br />sloughing or raveling of the cut bank was a new 2-3 foot drop from the natural slope to <br />the cut slope which exposed roots of trees above the cut. <br />Three live Douglas-fir trees that have been affected by this action. These trees are <br />inventoried and described going from north to south. <br />Tree No. 1. Douglas-fir. A forked tree with measurements being 10" and 8" dbh <br />(diameter breast high). The tree is 5 feet back from the road cut and has a 2-foot drop to <br />the cut slope. Roots are exposed. <br />Tree No. 2. Douglas-fir. 16" diameter. Forty-three (43) feet tall. It is 12 feet <br />back from the road cut. There is an approximate 2-3 foot drop from the bank to the cut <br />slope. Roots are exposed. <br />Tree No. 3. Douglas-fir. 8" diameter. Twenty-two (22) feet tall. It is two feet <br />from the edge of the cut with a 3-foot drop to the cut slope. Roots are exposed. <br />With the removal of the natural material the slope has become unstable. The scree slope <br />will naturally try to reach an angle of repose and will ravel or slough back 10-12 feet to <br />reach the existing slope. The existing slope is approximately 48%. The new cut slope is <br />about 80%. As the bank sloughs off, more tree roots will be exposed and eventually the <br />existing trees will topple or slide down the bank. The speed at which this will happen <br />will have to be determined by a geologist. It may occur in a yeaz or may take ten or more <br />years, but based on my experience, it will eventually happen. Only the replacement of <br />the removed material or the construction of a retaining structure will stop this action. <br />Appraisal Procedure: <br />To determine the value of the loss, the "Guide for Plant Appraisals" 9"' edition, 2000, has <br />been used. The Council of Tree and Landscape Appraisers prepared this Guide and the <br />International Society of Arboriculture published it. Cost of Cure, Cost of Repair, <br />