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4735 Bayview Lane <br />Everet4 Washington Geotechnical Report <br />Existing Site Conditions <br />The far eastern portion of the subject property contains the upper portion of the steep sided ravine <br />that descends down to Narbeck Creek. This slope is on the order of 80 feet tall with slope gradients <br />that appear to range from 1H:1 V to .75H:1 V. The slope face is generally heavily vegetated with <br />both coniferous and evergreen trees and native understory. The trees are generally mature and <br />straight with little to no leaning or pistol butting of the trunks. Some of the deciduous trees exhibit <br />some lean but is likely due to seeking sunlight as opposed to soil creep. The trees are missing at <br />the top of the slope in the center of the parcel. Reportedly, from a neighbor, this is due to a small <br />surficial landslide that occurred within the recent past. The top of the slope area is riddled with <br />mountain beaver burrows which likely contributed to the surficial instability in this area. There <br />are no visual indications of any deeper slope movement. Due to the steepness and heavy vegetation <br />on the slope face we were unable to traverse the slope. However, observation of both sidewalls of <br />the ravine did not disclose any vegetation that would indicate ground water daylighting on the <br />slope face in this area. To the best of our knowledge there are no other landslides within 200 feet <br />of the parcel. <br />The western approximate one-third of the parcel is nearly level. The central portion of the site, <br />from the top of the steep ravine to the existing house, forms a broad ravine that slopes gently <br />downward toward the Narbeck Creek drainage ravine at an inclination of about 10 percent. The <br />north and south sidewalls of the broad ravine slope downward at inclinations of 18 to 24 percent. <br />Our field evaluation did not find any slopes 25 percent or greater on the site other than the very <br />steep slope area along the drainage ravine. A flat area along the south property line appears to be <br />an old driveway that leads to an RV parking area The parking area was leveled by constructing <br />an approximate 30-inch-tall concrete rubble wall near the top and backfilling with loose fill soils. <br />The far eastern portion of the site is classified by the City of Everett as both a very high landslide <br />hazard and a high erosion hazard area. The portion of the site from the top of the steep slope <br />westward to the existing house is classified as a moderate landslide hazard on the city Landslide <br />Hazard Map. However, our field evaluation and measurements of slope angles indicates that there <br />are no slopes in this area of the site that are at least 25 percent slope gradient. Also, the underlying <br />soils are comprised of dense, granular glacial till or glacial drift. As such, it is our opinion these <br />gentle sloping areas should be classified as low landslide hazard instead of moderate landslide <br />hazard. The existing residence is located about 130 to 140 feet from the top of the very high <br />landslide hazard area. <br />Based on visual observation only of nearby properties, there are no obvious indications of springs, <br />seeps or other surface expressions of ground water on or off site within 200 feet of the project area <br />or that have the potential to affect or be affected by the planned construction. <br />Mappings and Other Nearby Studies <br />Gary A. Flowers, PLLC <br />5205 23`tl Avenue W Everett, Washington 98203 206-819-4304 <br />2 <br />