3005 PANAVIEW BLVD 2016-01-01 MF Import

July 10,1997 2 973-1164 2 SITE DESCRIP'TION '� Yout house is located in a rnsidential neighborhood outside of Everett,Washington,as shown on Figure 1,Site Vicinity Map. The neighborhood was located on an upland ridge eaet of I-5 ov.rlooking the Snohomish River Valley to the east. Your house was situated with the backyard located on the east side of the lot,facing the Snohomish River Valley. The honse is a one atory wood frame structure with a daylight basementfacing the backyard. The backyard was aituated at the crest of a steep ravine with a small stream at the bottom The natural ravine slopes wern between 35 to 40 degrees and wern densely � vegetated with brush and trees. The mud/debris failure was located on the east-facing slope of the ravine in your backyard approximaMly?A to 75 feet horizontally frnm the back of your house,as shown on Figure 2,Site Plan. The ground surface of the slide had been mvered with plastic after the slide had occurred. A wire fence had also been installed along the crest of the slope above the slide. The fence and the plastic were rnmoved forour geotechnical inveatigation. The main or upper-most scarp (break in ground surface) extended south of your property line onto the adjacent lot,the Lund residence(3007 Paiuview). The type of alide that occurred on your properly is termed a mud or debris • flow,which is characterized by the rapid downslope movement of saturated,loose surficial soila. A portion of the slope area in your yard adjacent to the north edge of the �' mud/debris flow slumped up to about a foot but did not flow down the hill. A similar � but much larger slump occurred in your neighbors yard on the south side of the mud/debris flow. That slump dropped vertically about five to six feet. • The geo�lry of the alope failure we observed in May was rnlatively unchanged at the ture of our field investigation in June. The inclination of the natural slope in the vicinity � of the failure was approximately 35 to 40 degrees and densely vegehated with trees and shrubs. The mud/debris flow was approximately 25 to 30 feet in width and extended downslope to the vicinity of the creek Tension cracks and minor slumping were � observed in the m.�in scarp area on the north side of the mud/debris flow(on your lot). • The slope of the failure at the main scarp,which is the uppermost breakin the ground surEace,wae about 40 degreea. The inclination of the middle portion of the failure was about 15 to 7A degrees and the surface was hummocky with a minor vegetative mver oE •� small shrubs and trees and scattered grasses. There is a small bench or break in slope within the mud/debris flow approximately 50 feet downslope from the main scarp. The � thiclatese of the material that failed in the mud/debris flow was only about one to two -� feet Several groundwater seeps were located within the mud/debris flow,and are shown on Figure 2,Site Plan. A groundwater seep is a surficial discharge of goundwater with relatively low flow velocities. — Golder Associates