Table 1. Database of reported landslides that occurred during the 2001 - 2002 wet season in Seattle and neighboring areas.

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Table 1. Database of reported landslides that occurred during the 2001 - 2002 wet season in Seattle and neighboring areas.

Landslide	Reference Area	Description¹	Damage/hazard¹	Date/time of occurrence	Field Checked
Number				information (reference)	(Y/N)

1	1600 block of 10th Ave E.,	Reactivation of deep-seated landslide.	Residential area--extent of damage/	November 2, 2001 (City of Seattle, unpub.	Y
	Seattle	Large volume of groundwater seepage	hazard undetermined.	data, 2002)
		from site was noted. Possible human
		influence cited (broken water pipes)
		(City of Seattle, unpub. data, 2002)

2	Schuster Parkway, Tacoma	Shallow flows originated from steep	Blocked southbound lane. Maintenance	"Wednesday's [11/14/01] drenching	Y
		exposure near west side of Parkway.	required.	rain ….closed some roads….Several
				small mudslides blocked the southbound
				lane of Schuster Parkway, according
				to Tacoma Public Works officials.
				Crews worked from 7:30 a.m. to
				1:30 p.m. before they reopened the
				lane." (Tribnet.com, 11/15/01)

3	3000 block of W. Galer,	Shallow slide. Possible human influence	Damaged back of small beach home and	The slide occurred at approximately	Y
	Seattle	(cut/fill location). Slide area is	approximately 30 ft of roadway behind	8:00 a.m. on 11/14/01. The occupant
		approximately 40-ft long, 30-ft wide,	home. Additional movement could	of the home was nearly hit by the slide
		and 10 ft high.	result in more damage to structure.	as she was leaving the house that
				morning (Dennis Callahan, local
				resident, oral commun. 2002).

4	1800 block of West Lake	Shallow debris flow from slope	"The mudslide brought silt and water	"Bellevue road crews spent most of	Y
	Sammamish Parkway,	along east side of highway. Granular	down the hill to Mallard Lane, below	Wednesday [11/14/01] and part of
	Bellevue.	slide material flowed down a 50 - 60 ft	West Lake Sammamish Parkway, and	yesterday [11/15/01] trucking in tons
		high slope to residential area below.	affected at least three property owners	of quarry rock to stabilize the 1800
		Scar approximately 30-ft wide, 40-ft	below…..one home bore the brunt of the	block of the parkway, which was
		long, and as much as 10-ft deep. Human	slide, with up to a foot of mud oozing	weakened dangerously by a mudslide….
		influence cited (pluggged culvert	through the first floor of the house."	On Wednesday, a backup in the culvert
		apparently a major factor).	(Eastsidejournal.com., 11/16/01; see	caused flooding that provoked a
			SeattleP-I.com photo in 11/15/01	mudslide…." (Eastsidejournal.com.,
			online issue).	11/16/01).
			"The mud was 16 inches thick at some	"The slide in the 1800 block
			points on the road" (Eastsidejournal.com	[of West Lake Sammamish Parkway]
			11/15/01).	came just as the Eastside's commute
			The slope failure partly undermined	was winding down." (SeattleP-I.com,
			the east side of West Lake Sammamish	11/15/01).
			Parkway (see photo, Seattletimes.com.,
			11/15/01).

5	North Ferdinand St (near	Shallow debris flow on steep slope	Temporarily closed North Ferdinand	"Wednesday's [11/14/01] drenching	Y
	North 46th St), Tacoma	underlain by colluvium. Slide track	Street.	rain ….closed some roads….Mudslide
		is approx 10-ft wide and 30-ft long.		closed North Ferdinand Street about
				11:30 a.m., but crews reopened the
				road to North 46th Street three hours
				later." (Tribnet.com., 11/15/01)
* Descriptive information missing or insufficient.
¹ 1 ft = 0.3048 m
Table 1 cont'd

Landslide	Reference Area	Description¹	Damage/hazard¹	Date/time of occurrence	Field Checked
Number				information (reference)	(Y/N)

6	Opposite 12720 Riviera Pl. NE,	Shallow flow, 5 - 10 yds of material,	Debris covered or partly covered	A slide (5-10 yds of material)	Y
	Seattle	1-2 ft thick, track is 3-12 ft wide	Burk-Gilman trail.	occurred opposite 12720 Riveria,
		Fresh scar 6 - 10 ft below crest of		Report received at 4:45 p.m. on
		bluff.		11/14/01. Slide occurred at
				approximately 3:00 p.m. on 11/14/01.
				(Rex Allen, City of Seattle, oral
				commun. 2001).

7	Soos Creek Trail at SE 240th,	*	Blocked section of Soos Creek	"The first major rainstorm of the	N
	Kent		Trail.	season brought mudslides to Western
				Washington yesterday [11/14/01]…..
				Soos Creek Trail at Southeast 240th
				Street in Kent was closed when a
				mudslide blocked the path." (Seattle
				times.com, 11/15/01).
				"A mudslide blocked a section of Soos
				Creek Trail at Southeast 240th Street
				in Kent. Clean-up efforts had not
				started yesterday afternoon." (South
				countyjournal.com, 11/15/01).

8	West Valley Highway at 15th	*	One lane of West Valley Highway at	"Auburn officials reported that one	N
	Street NW, Auburn		15th Street blocked	lane of West Valley Highway at 15th
				Street was blocked by a small slide
				for about an hour early yesterday
				afternoon before an Auburn maintain-
				ance crew was able to clear it."
				(Southcountyjournal.com, 11/15/01)

9	Near Highway 522 at Paradise	Shallow debris flows from 30- to 40-ft	Debris flow(s) shut down westbound	"Several roads in the suburbs east of	Y
	Lake Rd., south Snohomish	high mound of fill. Human influence	lanes.	Seattle were closed Wednesday
	County.	noted (mound appears to be a remnant of		[11/14/01]….Highway 522 in south
		highway construction). Slope areas		Snohomish County was reopened to
		as much as 60 ft across covered with		traffic Wednesday night, several
		plastic to prevent further sliding/		hours after a mudslide shut down
		erosion.		westbound lanes, said state Department
				of Transportation spokeswoman
				Melanie Moores." (HeraldNet.com.,
				11/16/01).

10	Opposite 12582 Riviera Pl. NE,	Shallow slide scar exposes sand	Covered part of Burke-Gilman trail.	A slide (approximately 40 yds of	Y
	Seattle	above ledge of fine-grained material		material) occurred opposite 12582
		(siltstone?). Scar is 15-20 ft high,		Riviera Dr. NE between midnight and
		25-30 ft wide, and 1-3 ft thick.		7:00 a.m. on 11/15/01 (Rex Allen,
				City of Seattle, oral commun., 2001).

Table 1 cont'd

Landslide	Reference Area	Description¹	Damage/hazard¹	Date/time of occurrence	Field Checked
Number				information (reference)	(Y/N)

11	Opposite 13038 Riviera Pl. NE,	Shallow slide 10-15 ft high. Most	Covered part of Burke-Gilman trail.	Another slide opposite 13038	Y
	Seattle	active part on south end is 10-30 ft	Required maintenance.	Riviera Dr. NE occurred between
		wide. Trees had to be removed due		midnight and 7:00 a.m. on 11/15/01.





		the slide. Slide debris is fine-grained		(Rex Allen, City of Seattle, oral
		brown colluvium derived from horizon-		commun., 2001).
		tally bedded sediments. Total slide
		area is approximately 25-30 ft wide.
		Many drain lines cross slide area from
		bench above.

12	Opposite 11728 Riviera Pl. NE,	Small debris flow track 3-6 ft wide	May have covered part of Burke-Gilman	Slide opposite 11728 Riviera Dr. NE	Y
	Seattle	and ~20-30 ft high. Horizontally-	trail. Required maintenance.	occurred at or just before noon on
		bedded, brown natural sediments		11/15/01 (Rex Allen, City of Seattle,
		exposed in the scar. Deposit is several		oral commun., 2001).
		inches thick. Debris may have reached
		Burke-Gilman trail but has been cleared.
		Deposit consists of mixture of sand
		and fines with fragments of siltstone
		and claystone.

13	Opposite 12328 Riviera Pl. NE,	Minor slide where loose debris	No damage to structures.	Slide opposite 12328 Riviera Dr. NE	Y
	Seattle	may have slid off ledge.		occurred between noon and 5:00 p.m. on
				11/15/01 (Rex Allen, City of Seattle,
				oral commun., 2001).

14	Opposite 13200 Riviera Pl. NE,	*	*	"Slide opposite 13200 Riviera Dr. NE	N
	Seattle			occurred between noon and 5:00 p.m. on
				11/15/01." (Rex Allen, City of Seattle,
				oral commun., 2001).

15	Discovery Park, northwest	*	Slide/debris flow took out part of	Slide in Discovery Park occurred	N
	Seattle		trail.	on 11/15/01. The slide took out part
				of a trail (Mark Orth, City of Seattle.
				oral commun., 2001).

16	Opposite 13200 Riviera Pl. NE,	Enlargement of slide (that occurred on	Continued movement in the area may	New cracks have developed on hillside	Y
	Seattle	11/15/01) indicated by development	threaten fire hydrant and water line.	above slide that occurred on 11/15/01,
		of ground cracks 25-30 ft above slide		opposite 13200 Riviera Dr. NE. The
		on south side.		cracks are located 25-30 ft above
				slide. The new movement was reported
				at noon on 11/19/01 (Rex Allen,
				City of Seattle, oral commun., 2001).

17	12000 block of 42nd Ave. NE,	*	*	City received notificaton/request	N
	Seattle			regarding occurrence of landslide
				on 11/19/01 (unpub. City of Seattle
				database, 2/6/02)

18	3600 block of NW 65th Court,	Shallow slide. Human influence noted	Estimated $10,000 damage to retaining	"It [the retaining wall/fill failure]	Y
	Seattle	(approximately 15 ft of a 10-ft high	wall and yard. Maintenance required	occurred about 6:00 a.m. on 11/21/01.
		retaining wall, and fill behind wall,	to clear and reopen NW 65th Court.	I was outside at the time and heard the
		failed onto street).		noise". (Jana Davis, local resident, oral
				commun., 2002)
Table 1 cont'd

Landslide	Reference Area	Description¹	Damage/hazard¹	Date/time of occurrence	Field Checked
Number				information (reference)	(Y/N)

19	1900 block of 4th Ave. NW,	Shallow slide/garden wall failure.	Estimated $5,000 damage.	City received notificaton/request	Y
	Seattle	Possible human influence.		regarding garden wall failure on
				11/21/01 (unpub. City of Seattle
				database, 2/6/02).

20	12300 block of 25th Ave. NE ,	Shallow sloughing and water erosion	Minor damage to 25th Ave. NE.	City received notificaton/request	Y
	Seattle	near culvert damaged part		regarding road damage due to slide on
		of roadway. Possible human influence.		11/21/01 (unpub. City of Seattle
				database, 2/6/02).

21	Fay Road NE near SR 203,	*	Major highway maintenance and slope	"SR 203 has been reopened. The state	N
	approximately 4 mi south of		repair required.	highway was closed for 19 hours Friday
	of Duvall.			[11/23/01] when it was hit by several
				mudslides originating from blocked
				culverts along Fay Road northeast, east
				of SR 203. Crews have cleared debris
				from the roadway and removed unstable
				material from the slope located east of
				the roadway". (Eastsidejournal.com.,
				11/25/01)
				"The first slide covered one lane, but