4702 W GLENHAVEN DR 2020-06-16 - Laserfiche WebLink

Oskar Property Deck Limited CAO,Everett,WA Materials Testing&Consulting,Inc. July 17.2019 19B182 General Site and Slope Conditions: The project site is in a developed residential area southwest of the center of Everett, Washington. The neighborhood is developed with similar sized residences on 1/4-to '/2-acre lots. Residences of similar size, nature, and setback as the subject home border to the east and southwest of the site, as well as to the north of the site below the subject slope. Multiple larger forested tracts remain unworked running north to south in the project site vicinity and beyond,presumably undeveloped due to challenging topography and natural features. Pigeon Creek Number 2 is the closest surface water feature in the vicinity, located approximately 750 feet to the east of the project site. Puget Sound is the next closest major water feature, approximately one-half mile to the north of the project site and at a significantly lower elevation. Current conditions of the property include a single-family residence occupying the majority of the central upland site pad, and driveway access from the narrow southern end of the site at the cul-de-sac frontage. The residence is located near the top of a large and continuous slope bordering to the north and northwest. The site pad is approximately 40 feet in elevation above mean sea level according to topographic maps. The building area for the proposed deck extending from the northwest wall of the home is currently partially occupied with a concrete patio. Nearby vegetation on the upland pad behind the house includes manicured lawn and residential landscaping. A recent deck addition was completed at the northeast end of the house extending to approximately 13 feet from the slope (noted on Figure 2). The site slopes very gently north from the entry until reaching the critical area slope crest, then breaks downward. The primary slope descends to the north and northwest at approximately 30 degrees on average for at least 20 vertical feet to beyond the property limits. Previous direct profiling by MTC done on site nearby to the east indicates the slope is around 25 to 30 feet high in total. The primary slope to the northwest below the proposed deck was not readily accessible to traverse at the time of this study due to a chain-linked fence. The slope face was observed from the accessible area to be densely vegetated and appeared undisturbed, covered with large trees, shrubs, and flowering plants. The upper slope face below the crest bordering the residential yard is generally covered with unmaintained longer grasses. During reconnaissance, the upper part of the slope was observed directly as access allowed for indications of localized or larger-scale instability or major erosional issues that may influence the viability of the proposed deck project. No obvious features were observed that would indicate an active or recent failure,of the upper slope, such as tension cracks, exposed headscarps, jack-strawed or tilted trees, or downslope accumulations. Topography was generally consistent along the slope face and on the site pad near the crest. No obvious evidence of rotational or translational failures were observed on the slope in proximity of the proposed deck. The slope face did not exhibit bare areas or conspicuous regrowth patterns, and only minor evidence of surface soil creep was observed. Erosional hazard appears to be low due to the well-established forest vegetation. 3 ��