2720 59TH ST SW 2022-06-21 - Laserfiche WebLink

GEOENGINEERS Memorandum 17425 NE Union Hill Road Suite 250,Redmond,WA 98052,Telephone:425.861.6000,Fax:425.861.6050 www.geoengineers.com To: Tom Hood, PE, City of Everett From: Debra Overbay, PE and Cody Gibson PG, GeoEngineers, Inc. Date: February 28, 2022 File: 0661-133-00 Subject: Geotechnical Memorandum 2702 59th Street SW Landslide Assessment INTRODUCTION This memorandum presents a summary of our geotechnical evaluation of the recent landslide that occurred within the private property of 2702 59th Street SW. The site is located in the southwest portion of the City of Everett on the east side of Powder Mill Gulch.The recent landslide extends across two residences (2702 and 2710 59th Street SW). Most of the slope failure and visible displacement are in the backyard of the private property at 2702 59th Street SW. We understand that the landslide occurred following a rain-on-snow event in late December,and that noticeable additional movement has not been visually observed since the initial slide.Our services were requested by you to complete a site visit and preliminary qualitative assessment of the landslide. SITE OBSERVATIONS We visited the site on January 24, 2022. The failure is a rotational arcuate-shaped landslide extending approximately 200 feet from east to west with a scarp height of approximately 1 to 5 feet.The main body • of the slope failure is within and below the 2702 59th Street SW property and is slightly back tilted towards the scarp (refer to Photos r 1 and 2). A broken perforated, drain pipe and an irrigation pipe were exposed within the scarp. The scarp on the western property (2710) 'j,,:e4. ; extends through a collapsed shed and to the east side of the walkway. • The approximate location of the scarp is shown in Figures 1 and 2. ry w.4 � w ,1• ,= i "'TS Photo 1.Looking West at Head Scarp o to'4 , and Exposed Pipes Photo 2. Fence at 2702,Cleared Area with Debris Downslope