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REF_ C, F . Fit-
CC
This agreement made this llth day of February , 19 85 , by
and between King County, a political subdivision —of the tate o WasFii gton,
hereinafter termed the Grantor, and the City of Renton , hereinafter termed
the Grantee.
WITNESSETH:
STORM DRAINAGE EASEMENT
That for and in consideration of mutual benefits, the Grantor herein does
by these presents grant unto the Grantee, its successors and assigns,
easements and right of way over, through, under, across and upon the following
described property, situated in King County, Washington, to wit:
EASEMENT "A"
That portion of the Northwest 1/4 of the Southeast 1/4 of Section 16,
Township 23 North, Range 5 East, W.M., King County, Washington, being a
strip of land 15 feet in width having 7.50 feet on each side of the
centerline described as follows:
COMMENCING at the Southeast corner of said subdivision; thence N 1004'23"
E along the East line thereof 170.21 feet to the POINT OF BEGINNING of
said easement and centerline; thence S 55°41'00" W 50.00 feet; thence S
78000'00" W 87.00 feet; thence N 80°00'00" W 150.00 feet; thence S
67040'00" W 195.00 feet; thence S 53037'48" W 112.05 feet; to the South
line of said subdivision and the terminus of said centerline. '
LO Purpose: Easement "A" The Grantee shall have the right to construct,
O reconstruct, operate, maintain, and repair its storm drainage pipe line
with necessary appurtenances over, under and upon the above described strip of
land.
r;]
in EASEMENT "B"
GO
That portion of the Northwest 1/4 of the Southeast 1/4 of Section 16,
Township 23 North, Range 5 East, W.M., King County, Washington, being a
strip of land 40 feet in width described as follows:
The South 40.00 feet of the West 800.00 feet of the Northwest 1/4 of the
Southeast 1/4 of Section 16, Township 23 North, Range 5 East, W.M., King
County, Washington.
Purpose: Easement "B" The Grantee shall have the right to construct,
reconstruct, operate, maintain, and repair an open storm drainage ditch and
service road within the above described strip of land.
The Grantor and Grantee herein, by accepting and recording this easement
mutually covenant and agree to the terms and conditions described in detail in
Appendix "A" attached hereto and by this reference made part of this
agreement.
DATED this llth day of _February 1985 .
°n tin KING COUNTY, WASHINGTON
By
e e
TITLE
oun xecu i v e
w ►- o y
cr m DATE JA N 2 9 1985-
Filed Fo� �r , Ft, ^jse.st Of
cord
Page 1 `
r:nt �' �� F oput, Division
King Co y C; __ '.�.--
STATE OF WASHINGTON)
COUNTY OF KING ) ss
On this day personally appeared before me
to me known to be the T County Executive of g County, Washington,
the person who signed the a o and foregoing instrument for King County for
the uses and purposes therein stated and acknowledged to me that he signed the
same as the free and voluntary act and deed of King County and that tie was
authorized to so sign.
GIVEN under my hand and official seal this
1Tff .
CITY OF RENTON
STATE OF WASHINGTON)
COUNTY OF KING ) ss
day o
�V
&44-'61 0, A�-
i h an or tie
State of 'Wash i nator, r"!§ te,i na
a t Z)
Barbara7 Y. Shinpoch
TITLE Mavor
DATE February 8, 1985
ATTEST �er��
City Clerk
On this day personally appeared before me ine Motor
to me known to be the person who signed the above an en foregoing ins or
the uses and purposes therein stated and acknowledged to me that he signed the
same as the free and voluntary act and deed of the Representative of City
and that he was authorized to so sign.
GIVEN under my hand and official seal this 8th day of February ,
1985 .
f NOTARY-P I in and for the
State of ington residing
? a t
APPROVED AS TO FORM & LEGALITY:
BY /
De 0 uty-'PIo�
DATE /U
Page 2
37/SDE2
APPE14DIX "A"
Terms and conditions applicable to easements "A" and "B" granted by King
County.
1. PERMIT REQUIRED: Before any work is performed under this agreement,
Grantee must o ainaright of way construction permit or a special use permit
from the Real Property Division. To obtain said permit, Grantee shall submit
complete plans and specifications of the proposed project including details of
landscaping, and comply with any and all other provisions as more specifically
set forth in the permit application.
2. DAMAGES: In the event that any damage of any kind is caused by
Grantee ink course of performing any act authorized by this easement,
Grantee shall immediately reimburse the damaged party to the full extent
necessary to restore said party to the position he would have held absent said
damage.
3. ASSESSMENTS: Neither Grantor, nor its property shall be subjected to
any charge, assessment or expense arising from, growing out of, or in any way
attributable to, the use, occupance, or actions authorized herein, whether
within or without the confines of Grantor's property. If Grantor or its
property is legally subjected to any such charge, assessment or expense,
Grantee shall pay Grantor, as additional compensation for the rights granted
in this instrument an amount of money equal to any such charge, assessment or
expense paid by the Grantor.
4. HOLD HARMLESS: The Grantee agrees to protect and save King County,
its elected an -appointed3 officials and employees while acting within the scope
LO of their duties as such, harmless from and against all claims, demands and
causes of action of any kind or character, including the cost of defense
thereof, arising in favor of the Grantee's employees or third parties on
account of personal injuries, death or damage to property arising out of the
premises herein or in any way resulting from the acts or omissions of the
cc Grantee and/or its agents, employees or representatives.
5. HIRING AND EMPLOYMENT: In all hiring or employment made possible or
resulting from this agreement, there shall be no discrimination against any
employee or applicant for employment because of sex, age, race, color, creed,
national origin, marital status or the presence of any sensory, mental, or
physical handicap, unless based upon a bonafide occupational qualification,
and this requirement shall apply to but not be limited to the following:
employment, advertising, lay-off or termination, rates of pay or other forms
of compensation, and selection for training, including apprenticeship. No
person shall be denied or subjected to discrimination in receipt of the
benefit of any services or activities made possible by or resulting from this
agreement on the ground of sex, race, color, creed, national origin, age,
except minimum age and retirement provisions, marital status, or the presence
of any sensory, mental or physical handicap. Any violation of this provision
shall be considered a violation of a material provision of this agreement and
shall be grounds for cancellation, termination or suspension in whole or in
part of the agreement by the County and may result in ineligibility for
further County agreements.
6. RESERVATIONS: Grantor reserves to itself, licensees, lessees,
successors and assigns, the right not only to continue to keep and use or
operate all other facilities or structures now upon or beneath the surface of,
or above, the said described premises, but also the right to install and use
or operate other facilities and structures, provided that said installations
may be made without substantial interference with the use of the said premises
as provided in this instrument.
7. ASSIGNMENT: Neither this easement nor the rights of the Grantee
hereunder shall e assignable in whole or in part without the prior written
consent of the Grantor. All the provisions, conditions, requirements and
regulations herein contained shall be binding upon the successors and assigns
of the Grantee and all privileges of the Grantee shall be given to such
successors and assigns if they were specifically mentioned.
Page 1 of 2
37/SDE3
8. TERMINATION AND ABANDONMENT: If the use of the easement on the
premises described in—f is ins rument for the purposes expressed herein shall
be abandonded or discontinued, or if the Grantee violates any provision of
this instrument, the said easement shall thereupon cease and terminate, and
Grantee shall surrender or cause to be surrendered to Grantor, to its
successors or assigns, the peaceable possession of the said described
premises, and title to the said premises shall remain in Grantor, or its
successors or assigns, free and clear of all rights and claims of Grantee.
Upon termination of the easement for any reason, Grantee shall remove at his
expense all facilities placed on said property by Grantee and restore the
premises to a condition which is equivalent in all respects to the condition
existing prior to installation of the facilities or to a condition which is
satisfactory to Grantor. If Grantee has not accomplished removal and
restoration at the end of a ninety day period following the effective date of
revocation, termination or abandonment, Grantor may acomplish all of the
necessary work and charge all of the costs to Grantee.
9. RESTORATION AFTER INSTALLATION: Following any construction, Grantee
shall return the rantor ss property to its original condition by fixing any
damage Grantee's construction caused to Grantor's property, including but not
limited to property damage to slopes, shrubbery, landscaping, fencing, roadway
or structures.
10. EMERGENCY SITUATIONS: In the event of an emergency, Grantee shall
take immediat—'— e steps to perform any necessary repairs, and in the event
Grantee fails so to do, Grantor may perform said necessary repairs at the sole
1.1*1 cost and expense of Grantee.
C
LO 11. OTHER APPLICABLE LAWS: Grantee shall comply with all federal, state
Ljand local laws, and assume all cost and expense and responsibility in
connection therewith, without any liability whatsoever on the part of Grantor.
Gp
Special terms and conditions:
1. The final design of the Sunnydale Mobile Home Park detention facility
has been approved for a maximum five (5) year release rate equal to 0.764
cubic feet per second and a twenty-five (25) year storm detention volume equal
to 45,916.0 cubic feet. Any increase in discharge rate shall require prior
approval by the King County Department of Public Works.
2. The improving and upgrading of the drainage ditch for the purpose of
enhancing storm water runoff shall be completed by the City of Renton within
four (4) years of the acquisition of the necessary rights in land owned by the
Estate of Anna McMahon referred to in special use permit #FS-122-83.
Page 2 of 2 37/SDE4
C
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ROADWAY AND UTILITIES 05f Z`
RE►: F 4.150
E A S E t•1 E N T r:ASHL.L
#t0648 E
***44. 50
55
THIS INSTRUMENT, made this 31st day of October__ 19 83
Ly and between Union Avenue Company,_^a Limited Partnership, organizer.
Under the la;13 of Washington, hereinafter called "Grantor(s) ," and the
C'TTY OF RENTON, a Municipal Corporation of King County, Washington
c,,.veinafuer called "Grantee."
WITNESSETH:
That said, Grantors) , for and in consideration of the surn of
10_00 _ _ _ paid by Grantee, and other valuable
con_ideration, do by these presents, grant, bargain, sell, convey, and
warrant unto the said Grantee, its successors and assigns, an easement
for roadway and public utilities (including water and sewer) with N
necessary appurtenances over, throuLh, across and upon the followint;
described property in King County, Washington, more particularily
described as follows.
The East 30.00 feet, the South 30.00 feet and the South 698.55
feet of the I -lest 30.00 feet of the Northeast 1/4 of the Southeast
1/11 of Section 16, Township 23 North, Range 5 East, W.m.
EXCEPT the North 330.00 feet of said Northeast 1/4 of the
Southeast 1/4,
Said heretofore mentioned grantee, its successors or assigns, shall have
the right, without prior notice or proceeding at law, at such times as may be
necessary to enter upon said above described property for the purpose of construct-
ing, maintaining, repairing, altering or reconstructing said roadway and utilities,
or making any connections therewith, without incurring any legal obligations or
liability therefore, provided, that such construction, maintaining, repairing,
altering or reconstruction of said roadway and utilities shall be accomplished in
such a manner that the private improvements existing in the right(s)-of-way shall
not be disturbed or damaged, they will be replaced in as good a condition as they
were immediately before the property was entered upon by the Grantee.
The Grantor shall fully use and enjoy the aforedescribed premises, including
the right to retain the right to use the surface of said right-of-way if such use
does not interfere with installation and maintenance of the roadway or utilities.
However, the grantor shall not erect buildings or structures over, under or across
the right-of-way during the existence of such roadway and utilities.
This easement, shall be a covenant running with the land and shall be bind-
ing on the Grantor, his successors, heirs and assigns. Grantors covenant that they
are the lawful owners of the above properties and that they have a good and lawful
right to execute this agreement.
Union Avenue Company
tt! � v ffnn
enehal P r n e r
FILED FOR RECORD AT REQUEST OF
OFFICE OF THE CITY CLERK
RENTON MUNICIPAL BLDG. -73r
200 MILL AVE SO.
RENTON, WA 98055
►.lct'� 9♦ :h'r1 �Ib! C•�4 �'0i txv:#"��1lfb'�O� V Y
510N OF
v C01UP�1 Y
-4;2j
deputy
Page 1 of 2
STATE OF WASHINGTON)
)ss
COUNTY OF KING )
I, the undersigned, notary public in and for the State of
Washington hereby certify that on this 31st day of October
19 83 personnally appeared before me---
--- --
to me known to be the individual(s) described in and who executed tho
foregoing instrument, and acknowledged that _ _-`
hesigned a,rW
sealed the same as his free and voluntary act and deed or the
uses and purposes therein mentioned.
of ry Public iri and: 430pb
Washington, resldinb,'`3�;�
d••�iaX3
p STATE OF WASHINGTON) 1
� )ss
r4 COUNTY OF )
This is to certify that on this day of _ 19
before me, the undersigned, a Notary Public, personally appeared
_and _
respectively of Metropolitan Savings and Loa_n Association of Seatt 'L--,...a
Washington Corporation to me known to be the individuals who execur,,�;l
the within dedication and acknowledged to me that they signed and
sealed the same as their voluntary act and deed for the uses and
purposes therein mentioned and on oath stated that they were authorr':aed
to execute said instrument and that the seal affixed is the corpOrcL";e
seal of said corporation.
WITNESS my hand and official seal the day and year first above
written.
Notary Public in and fur, the ;t.-.�t,, ut
Washington, residing; at
Page 2 of 2
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City of Renton
200 Mill Avenue South
Renton. WA 98055-2189
Fi LC
Po. A-6,#(tu
Consulting Engineers and Scientists
91 S ITT January 30, 1995
F EB -1 i995
Cl TY OF RENTON
Attention: Ronald J. Straka
Engineer►ng Dept`
Re: Sunnydale Mobile Home Park
Dear Mr. Straka:
We are enclosing the following invoice for services performed on the above -referenced
project:
December 31, 1995 Invoice No. G-1 $1,265.91
Sincerely,
Harza Northwest, Inc.
Albert Lio
Project Manager
Aich,udBielefeld
Engineering Geologist
Encl: as stated
2353 130th Avenue N.E., Suite 200 Plaza West 9600 S.W. Oak Street, Suite 350
Bellevue, Washington 98005 Portland, Oregon 97223
Tel: (206) 882-2455 Fax: (206) 883-7555 Tel: (503) 244-6922 Fax: (503) 244-6914
IL
INVOICE
HARZA NORTHWEST, INC.
2353 130TH AVENUE N.E.
SUITE 200
P.O. BOX C-96900
BELLEVUE, WASHINGTON 98005
TELEPHONE (206) 882-2455
-7555
City of Renton (`' DATE: December 31, 1994
200 Mill Avenue South INVOICE NO: G-1
Renton, WA 98055-2189 FEB 1 i995
CONTRACT
CITY OF RENTON REFERENCE: City of Renton Letter
Lngineerinu Dept- Dated 12/1/94
H: Docs: 94-1094
PROJECT NUMBER AND DESCRIPTION:
Sunnydale Mobile Home Park (7160G)
Professional Services (November 27,
1994 - December 31, 1994)
Name Hours
Billed Rate
Total
R.Bielefeld 7.0
$107.69
$753.83
S.Criswcll 2.0
36.98
73.96
A.Liou 4.0
108.28
433.12
Total Professional Services
Direct Costs
Electronic Computer (In -House)
$5.00
Total Direct Costs
TOTAL AMOUNT DUE
COT �:''JRRENCE
T IAVDATE
PC— 2-1
Current Period
$1,260.91
5.00
$1,265.91
WKi96LYVOICFSk?160G-I.DOCN01!30M%I 1.20 AM
! ' ^ p A Consulting Engineers and Scientists
December 12, 1994
City of Renton File: 716OG
200 Mill Avenue South Ser: 94-627
Renton, WA 98055-2189 Purchase Order # 87664
Attention: Ronald J. Straka, Engineering Supervisor
Dear Sir:
Per our conversations regarding costs and invoicing for the Sunnydale Mobile Home
park slope consultation, it is our understanding that you will issue a Purchase Order for
this work. Depending on need for review of the mobile home park's consultant report this
work may go into 1995.
We estimate that this work will require a total of 16 hours of services all inclusive
and recommend a value not to exceed $1,600.00 inclusive of the following:
Field visit
Report, draft and final
Consultants review
Clerical.
This work would be billed when completed in January 1995.
If this is not satisfactory, please call me at (206) 882-2455.
Z O
RJB/sdc
2353 130th Avenue N.E., Suite 200
Bellevue, Washington 98005
Tel: (206) 882-2455 Fax: (206) 883-7555
Very truly yours,
Haarrza Northwest, Inc.
Ri/ard J. ielefeld
Engineering Geologist
Plaza West 9600 S.W. Oak Street, Suite 350
Portland, Oregon 97223
Tel: (503) 244-6922 Fax: (503) 244-6914
032856 HARZA NW INC 87664 01/30/95
Vendor No. I Vendor Name .1 PO Date
6 CITY OF RENTON
r�l
HARZA NW INC
2353 130TH AV NE #200
BELLEVUE, WA 98005
Purchase Order
ORIGINAL
Chapter 116, Laws of 1965
City of Renton Certification
I, the undersigned, do hereby certify under penalty of perjury, that the
materials have been furnished, the services rendered, or the labor
performed as described herein, and that the claim is a just, due and
unpaid obligatio a inst the City of Renton, and that I am authorized to
authenticate a cer t id claim:
Signed
PLNG/BLDG/PUB WKS UTILITY SYS
FERKINGSTAD, LINDA
Qty
Unit
Description
Unit Price
Est. Amount
Account Number
WO/Func
Amount
Sunnydale Mobile Home Pk I
1,600.00
E 401.000000.018.5380.0030.41.000148
62011/5430
1,600.00
a 1 i 19 c �G-�-h o.�- .Q IvJ • G l l�/ 3 r l
II
�
f, 2(05 . a 1
1
Authorized By
1,600.00
1,600.00
Accounts Payable Div. • 200 Mill Ave. S. • Renton, WA 98055 • Phone (206) 235-2618 • Fax (206) 235-2513
DP 3119 11/94
FILE
Consulting Engineers and Scientists
December 12, 1994
City of Renton File: 716OG
200 Mill Avenue South Ser: 94-627
Renton, WA 98055-2189 Purchase Order # 87664
Attention: Ronald J. Straka, Engineering Supervisor
Dear Sir:
Per our conversations regarding costs and invoicing for the Sunnydale Mobile Home
park slope consultation, it is our understanding that you will issue a Purchase Order for
this work. Depending on need for review of the mobile home park's consultant report this
work may go into 1995.
We estimate that this work will require a total of 16 hours of services all inclusive
and recommend a value not to exceed $1,600.00 inclusive of the following:
Field visit
Report, draft and final
Consultants review
Clerical.
This work would be billed when completed in January 1995.
If this is not satisfactory, please call me at (206) 882-2455.
Very truly yours,
Harza Northwest, Inc.
Ri" and J. ielefeld
Engineering Geologist
RJB/sdc
2353 130th Avenue N.E., Suite 200 Plaza West 9600 S.W. Oak Street, Suite 350
Bellevue, Washington 98005 Portland, Oregon 97223
Tel: (206) 882-2455 Fax: (206) 883-7555 Tel: (503) 244-6922 Fax: (503) 244-6914
Fl -,
c.
Earl Clymer, Mayor
December 12, 1994
Sterling Coast Management Inc.
5339 Prospect Road #261
San Jose, CA 95129
CITY OF RENTON
Planning/Building/Public Works Department
Gregg Zimmerman P.E., Administrator
SUBJECT: SLINNYDALE MOBILE HOME PARK
SLOPE FAILURE WEST OF DETENTION POND
Dear Property Owner:
On Wednesday morning, November 30, 1994, City maintenance crews visited the
Sunnydale Mobile Home Park property and observed an erosion failure approximately
30 feet west of the northern corner of the detention pond. The failure location is at
the top of a steep slope. A section of land approximately 10 feet in diameter failed
and slid about 20 feet down the side slope.
The City crew observed stormwater runoff from the property coming down the gravel
access road from the asphalt road and flowing to the slope failure location. The gravel
on the south side of the road was washed away and a 2 to 4 inch deep erosion gully
had formed. Stormwater runoff from the flat area west of the detention pond may
have also flowed to the failure location. A garbage dumpster was also located at the
top of the slope that failed, which may have similarly contributed to the cause of the
slope failure.
The 18-inch corrugated metal pipe for stormwater drainage from the site is located
east of the failure location. A high pressure City water main and easement is located
along the west side of the detention pond and in the access road. The water utility
has temporarily cut off flow to the high pressure water main. The water main could
fail if the landslide erodes the soil around the water main which supports the pipe.
Other utilities downhill from the slide include a Seattle City Light power line and a high
pressure petroleum pipeline.
On Friday morning, December 2, 1994, City personnel and an engineering consultant
visited the site to determine the possible cause of the slope failure. They did not
observe any water flowing out of the bottom of the slope failure area. The
consultant's opinion was that the failure was caused by surface water saturating the
soil, causing the soil to lose strength and fail at the side of the slope. Further surface
water flow caused additional slope failure and erosion of the failed area.
The mobile home park's stormwater collection system, the detention pond, and the
discharge pipe from the control manhole are all part of a private stormwater drainage
system. The property owners are responsible for the maintenance and repair of the
stormwater system.
The City recommends that you take the following steps to repair the slope failure,
correct the stormwater runoff problems, and prevent the slope failure from damaging
public utilities:
1. Take immediate action to prevent surface water runoff from draining to the failure
area and causing additional slope failure. Additional slope failure could result in
damage to the private stormwater system and the City water main.
200 Mill Avenue South - Renton, Washington 98055
Sunnydale Mobile Home Park
Page 2
2. Retain a registered licensed civil engineer experienced in soil engineering and/or a
registered geotechnical engineer to inspect the slope failure site and private
stormwater system. The consulting engineer should prepare a plan to repair and
stabilize the slope failure area and prevent damage to the adjacent utilities. The
engineer should determine the exact location of the water main and show that the
proposed repair will support the design load from the maintenance access road,
City water main and private storm systems. The consulting engineer should also
be present during construction of the slope failure repair. This will allow the
engineer to provide technical assistance to the construction contractor and to
ensure that construction is completed as recommended by the consulting engineer.
3. The consulting engineer should review the existing private stormwater collection
system and develop plans to modify the collection system to prevent on -site runoff
from causing additional slope failure which could result damage to private and
public utilities. The 18-inch pipe in the failure area should be inspected to ensure
that it is not leaking. The potential for surface water runoff to travel down the
gravel access road should be eliminated. Runoff from the flat area around the
detention pond should be collected and routed into the existing stormwater system.
4. The slope repair and stormwater system modification plans are required to be
submitted to the City for review and approval. The slope repair plan should
include, at a minimum, a letter report describing the type of repair and how the
repair work will be completed, along with any necessary repair details showing how
the slope failure repair will be constructed by a contractor. The slope failure plan is
required to be stamped and certified by a Washington State registered professional
engineer.
5. The City will issue a Grade and Fill Permit and a Construction Permit for the repair
of the failed slope and storm system improvements. Chapter 10, Mining,
Excavation, and Grading Ordinance of the City Code authorizes the City to review
and issue permits for any grading of 500 cubic yards or less. This situation does
not qualify for an exemption under the Ordinance, since the proposed fill will be
greater than 1 foot in depth and will be placed on a slope steeper than 5 to 1 . The
City will provide an expedited review of plans, since further slope failure could
damage private and public utilities and threaten public safety. The permit for
repairs will be a no -fee permit.
Please contact Ron Straka, Surface Water Utility Engineering Supervisor, at (206)
277-5548 to discuss the repair of the slope failure and to establish a time for a
meeting with you, or your representative, and your consulting engineer to arrange for
the review and approval of plans to solve this problem.
Sincerely,
Gregg Zimmerman, P.E., Administrator
Planning / Building/ Public Works Department
H:DOCS:94-1 107:DWC:ps
CC: Larry Warren Ron Olsen Jack Crumley i t s� �yrtsr GU
Neil Watts Ron Straka &Ail R.
It
CRY of RENTON
RECE,vm �; , Earth Consultants Inc.
DEC2 91994 it C➢eotechnical Engineers. Geologists & Environnwntal Scientists
December 28," TDW-- E-1894-4
Sunnydale Mobile Home Park
375 Union Avenue Southeast
Renton, Washington 98059
Attention: Gail Roy
Subject: Site Reconnaissance
Slope Failure West of Lot 170
Sunnydale Mobile Home Park
Renton, Washington
Mrs. Roy: '2.�; 2- 7 -7 - (J/,.-
�fz5- 277- 4/3&4 Fi\,
As requested, we have evaluated a slope failure west of Lot 170. The scope of our
evaluation was outlined in our proposal dated December 21, 1994. Earth Consultants, Inc.
(ECi) previously developed recommendations for site development and performed density
tests during grading operations in 1983.
During our site reconnaissance on December 27, 1994, we observed the failure to be at
the top of a steep slope approximately thirty feet west of the northern corner of the
detention pond behind Lot 170. A section of land approximately fifteen feet in diameter
failed and slid down the side slope. A dumpster rests approximately twenty feet from the
top of the slope in the failure area. The soils in the failure area consist of silty sand with
gravel and silty gravel. We estimate that the original slope gradient was approximately
0.75H:1 V in the area of the failure.
During our visit we also observed a two to four inch deep erosion gully on the south side
of a gravel access road located between Lots 169 and 170. A letter from the City of
Renton, dated December 12, 1994, indicated that a city maintenance crew observed
water running down the erosion gully to the failure location. At the time of our visit we
did not observe any water running in the erosion gully. However, we did observe heavy to
moderate groundwater seepage coming from the soils exposed by the slope failure. The
seepage was observed in the failure area approximately twelve to fifteen feet from the top
of the slope. We also observed a storm water manhole to the north of the slope failure.
The manhole revealed an eighteen (18) inch corrugated metal pipe oriented in the
northeast -southwest direction running about half full. The pipe appears to cross or be in
the immediate vicinity of the failure location.
1805 - 136th Place N.E., Suite 201, Bellevue, Washington 98005
Bellevue (206) 643.3780 Seattle (206) 464-1584 FAX (206) 746.0860 lacoma (206) 272-6608
L
Sunnydale Mobile Home Park E-1894-4
December 28, 1994 Page 2
During our site visit we noticed that a water utility east of the failure area was located
with blue paint. The utility line location marks were approximately ten feet from the failure
area. We anticipate that the utility is at least eighteen inches below the ground surface.
Based on the conditions observed, it appears that there is adequate support for the water
line at this time.
We also observed a slide scarp approximately six feet in diameter located approximately
thirty feet to the north of the subject failure. The slide scarp was located ten to fifteen
feet from the top edge of the slope. Based on the ground cover (leaves and small brush),
it appears this slide occurred approximately one to two years ago. In addition, vegetation
patterns on the slope in the vicinity of the failure area indicate that some areas are
unstable. Additional slides should be expected. Based on our observations, we anticipate
that they will be relatively small and isolated. In our opinion, additional slides should pose
a minimal risk to the overall stability of the slope provided the recommendations contained
in this letter are followed.
Based on the conditions described above, it appears that the subject failure was induced
by a combination of surface water and groundwater infiltrating and saturating the soil,
causing the soil to lose strength and fail. The weight of the dumpster may have also
contributed to the failure.
As previously mentioned, most of the surface water appeared to travel to the failure
location from the erosion gully in the access road. Some surface water may have also
come from the flat area west of the detention pond. It is difficult to determine the origin
of the groundwater. Some natural groundwater seepage may exist, however,
groundwater seepage could also come from leaking utility lines (i.e. 18" CMP). The 18"
utility line should be checked for leaks prior to any slope repair operations. The storm
water collection system should be evaluated by the original designer, Group Four, Inc.
Surface water runoff should be diverted from the top of the slope to minimize the potential
for further slope failures.
Earth Consuhants, Inc.
Sunnydale Mobile Home Park
December 28, 1994
E-1894-4
Page 3
In our opinion, the slope repair operations should consist a series of terraced rockeries.
The rockeries should be no greater than four feet in height and should be backfilled with
free draining material (i.e. quarry spalls, ballast, etc.). All loose soil left by the slide should
be removed from the failure area. The bottom of the rockeries should be keyed into
competent native soil at least eighteen (18) inches. The sides of the rockeries should also
be keyed -in to competent native soil at least twelve (12) inches. The rockeries should be
constructed in accordance with the attached Associated Rockery Contractors Standard
Rockery Construction Guidelines.
An ECI representative should be on -site during the repair work to verify that the slope
repair operations are in accordance with the recommendations contained in this letter.
If you have any questions or need additional information, please call.
Sincerely,
EARTH CONSULTANTS, INC.
Ja on Black
aff Engineer
2�
Kyle R. Campbell
Manager of Geot
JB/KRC/kc
Exroi7Es,Il,ylaCo
Attachment: ARC Guidelines
zI a_"5I"
Earth Consultants, Inc.
agmaeiated Vaehery eawteactaw
P.O. Box 1794 Woodinville, Washington 98072
(206) 481-3456 or (206) 481-7222
ASSOCIATED ROCKERY CONTRACTORS
STANDARD ROCKERY CONSTRUCTION GUIDELINES
1.01 Introduction:
1.01.1 Historical Background: These standard rockery construction guidelines have been developed in an effort
to provide a more stringent degree of control on rockery materials and construction methodology in the Pacific
Northwest. They have been assembled from numerous other standards presently in use in the area, from expertise
provided by local geotechnical engineers, and from the wide experience of the members of the Association of
Rockery Contractors (ARC).
1.01.2 Goal: The primary goals of this document are to standardize the methods of construction for rockery walls
over four feet in height, and to provide a warranty for the materials used in construction and the workmanship
employed in construction. This standard has also been developed in a manner that makes it, to the best of ARC's
knowledge, more stringent than the other standards presently in use by local municipalities.
2.01 Materials:
2.01.1 Rock Ouality: All rock shall be sound, weathering resistant, angular ledge rock. The longest dimension
of any individual rock should not exceed three times its shortest dimension. Acceptability of rock will be
determined by laboratory tests as hereinafter specified, geologic examination and historical usage records.
All rock delivered to and incorporated in the project shall meet the following minimum specifications:
a. Absorption
b. Accelerated Expansion (15 days)
(CRD-C-148) *1, *2
c. Soundness
(MgSO4 at 5 cycles)
(CRD-C-137)
d. Unconfined Compressive Strength
ASTM D 2938-79 (reapproved 1979)
Not more than 2.0% for igneous and metamorphic rock types.
Not more than 3.0% for sedimentary rock types.
Not more than 15% breakdown
Not greater than 5% loss
Intact strength of 15,000 psi, or greater for igneous and
metamorphic rocks, and 8000 psi orgreater for sedimentary rock
*1. The test sample will be prepared and tested in accordance with Corps of Engineers Testing procedure CRD-C-
148, "Method of Testing Stone for Expansive Breakdown on Soaking in Ethylene Glycol." Test requirements of not
more than 15 percent breakdown will be computed by dividing the number of individual pieces of initial sample
suffering breakdown (that is, separating into two or more pieces) by the total number of initial pieces in the sample.
*2. Accelerated expansion tests should also include analyses of the fractures and veins found in the rock. Many
problems associated with rockery failures are related to the rock fractures and veins found within the rock and not the
rock itself.
2.012 Frequency of Testine: Quarry sources for rockery rock shall begin a testing program when either becoming
a supplier or when a new area of the source pit is opened. The tests described in Section 2.01.1 shall be
performed for every four thousand (4000) tons for the first twelve thousand (12000) tons of material blasted and
removed to establish that specific rock source. The tests shall then be performed once a year or at an apparent
change in material. If problems with a specific area in a pit or with a particular material are encountered, the
initial testing cycle shall be restarted.
2.013 Rock Density: Recognizing that numerous sources of rock exist, and that the nature of rock will vary not
only between sources but also within each source, the density of the rock shall be greater than one hundred fifty-
five (155) pcf. Typically, rocks used for rockery construction shall be sized approximately as follows:
Rock Size Rock Weieht
Small to large 50-200 pounds
one man
Small to large 200-700 pounds
two man
Small to large 700-2000 pounds
three man
Small to large 2000-4000 pounds
four man
Five Man 4000-6000 pounds
Six Man 6000-8000 pounds
Two and one-man rock, and sometimes smaller, are often used to fill surface gaps along the top of the completed
rockery to create an aesthetically pleasing surface. This is an acceptable practice provided none of the events
described in Section 3.01.5 occur, and that the owner prevents people from climbing or walking on the completed
rockery.
In rockeries over eight feet in height, it should not be possible to move the large sized rocks (four to six -man size)
with a prybar. If these rocks can be moved, the rockery should not be considered capable of restraining any
significant lateral load. However, it is both practical and even desirable that smaller rocks, particularly those used
for "chinking" purposes, can be moved with a prybar to achieve the "best fit".
2.01.4 Submittals: The rock source shall present current geologic and test data for the testing for the minimum
guidelines described in Section 2.01.1 on request by either the rockery contractor, the client, or the applicable
municipality.
3.01 Rockery Construction:
3.01.1 General: Rockery construction is a craft and depends largely on the skill and experience of the builder.
A rockery is a protective system which helps to retard the weathering and erosion process on an exposed cut or
fill soil face. While by its nature (the mass, size and shape of the rocks) it will provide some degree of reten-
tion, it is not a designed or engineered system in the sense a reinforced concrete retaining wall would be
considered designed or engineered. The degree of retention achieved is dependant on the size of rock used; that
is, the mass or weight, and the height of the wall being constructed. The larger the rock, the more competent
the wall. To accomplish this, all rockeries in excess of four feet in height should be built on a "mass" basis.
To provide a competent and adequate rockery structure, all rockeries constructed in front of either cuts or fills
in excess of eight feet in height should be bid and constructed in accordance with these standard guidelines and
the geotechnical engineers supplemental recommendations. Both the standard guidelines and the supplemental
geotechnical recommendations should be provided to prospective bidders before bidding and the start of
construction.
The same geotechnical engineer should be retained to monitor rockery construction and to verify, in writing, that
the rockery was constructed in general accordance with this ARC standard and with his supplemental recommenda-
tions, in a professional manner and of competent and suitable materials.
3.01.2. Geotechnical En ineem The geotechnical engineer retained to provide necessary supplemental rockery
construction guidelines shall be a practicing geotechnical/civil engineer licensed as a professional civil engineer in
the State of Washington who has at least four years of professional employment as a geotechnical engineer in
responsible charge, including experience with fill construction and stability and rockery construction. The
geotechnical engineer should be hired either by the rockery contractor or the client.
3.013 Responsibility: The ultimate responsibility for rockery "design" and construction should remain with the
rockery builder. However, rockeries protecting moderate to thick fills, with steep sloping surfaces above or below
them, with multiple steps, with foundation or other loads affecting them, protecting sandy or gravelly soils subject
to ravelling, with seepage or wet conditions, or that are more than eight feet in height, all represent special
conditions and require consultation and/or advice from qualified experts.
3.01.4 Workmanship: All workmanship is guaranteed by the rockery contractor and all materials are guaranteed
by supplying quarry for a period of six years from the date of completion of erection, providing no modification
or changes to the conditions existing at the time of completion are made.
3.015 Changes to Finished Product: Such changes include, but are not necessarily limited to, excavation of
ditches or trenches within a distance of less than 1.5 times the rockery height measured from the toe of the
rockery, removal of any material from the subgrade in front of the rockery, excavation and/or removal of material
from any location behind the rockery within a distance at least equal to the rockery's height, the addition of any
surcharge or other loads within a similar distance of the top of the rockery, or surface or subsurface water forced,
directed, or otherwise caused to flow behind the rockery in any quantity.
3.01.6 Slopes: Slopes above rockeries should be kept as flat as possible, but should not exceed 2:1 (Horizon-
tal:Vcrtical) unless the rockery is designed specifically to provide some restraint to the load imposed by the slope.
Any slope existing above a completed rockery should be provided with a vegetative cover by the owner to help
reduce the potential for surface water flow induced erosion. It should consist of a deep rooted, rapid growth
vegetative mat and typically will be placed by hydroseeding and covered with a mulch. It is often useful to overlay
the seed and mulch with either pegged in -place jute matting, or some other form of approved geotechnical fabric,
to help maintain the seed in -place until the root mat has an opportunity to germinate and take hold.
3.01.7 Monitoring: All rockeries constructed against cuts or fills in excess of eight feet in height shall be
periodically monitored during construction by the geotechnical engineer to verify the nature and quality of the
materials being used are appropriate, that the construction procedures are appropriate, and that the wall is being
constructed in a generally professional manner and in accordance with this ARC standards and any supplemental
recommendations.
On completion of the rockery, the geotechnical engineer shall submit to the client, the rockery contractor, and to
the appropriate municipality, copies of his rockery examination reports along with a final report summarizing
rockery construction.
3.01.8 Fill Compaction: Where rockeries are constructed in front of a fill, it is imperative that the owner ensure
the fill be placed and compacted in a manner that will provide a competent fill mass. To achieve this goal, all
fills should consist of relatively clean, organic and debris free, granular materials with a maximum size of four
inches. Ideally, but particularly if placement and compaction is to take place during the wet season, they should
contain no more than five percent fines (silt and clay size particles passing the number 200 mesh sieve).
All fills should be placed in thin lifts not exceeding ten inches in loose thickness. Each lift should be compacted
to at least 95 percent of the maximum dry density, as determined by ASTM Test Method D-1557-78 (Modified
Proctor), before any additional fill is placed and compacted. In -place density tests should be performed at random
locations within each lift of the fill to verify this degree of compaction is being achieved.
3.01.9 Fill Construction and Reinforcement: There are two methods of constructing a fill against which to build
a rockery. The first, which typically applies to rockeries of less than eight feet in height, is to overbuild and then
cut back the fill. The second, which applies to all rockeries in excess of eight feet in height, is to construct the
fill using a geogrid or geotechnical fabric reinforcement.
Overbuilding the fill allows for satisfactory compaction of the fill mass out beyond the location of the fill face to
be protected. Overbuilding also allows the earthwork contractor to use larger and more effective compaction
equipment in his compactive efforts, thereby typically achieving a more competent fill mass. Cutting back into
the well compacted fill also typically results in construction of a competent near vertical fill face against which to
build the rockery.
For the higher rockeries the use of a geogrid or geotechnical fabric to help reinforce the fill results in construction
of a more stable fill face against which to construct the rockery. This form of construction leads to a longer
lasting and more stable rockery and helps reduce the risk of significant long term maintenance.
This latter form of construction requires a design by the geotechnical engineer for each specific case. The vertical
spacing of the reinforcement, the specific type of reinforcement, and the distance to which it must extend back into
the fill, and the amount of lapping must be determined on a rockery -by -rockery basis.
3.01.10 Rockery KevwaN- The first step in rockery construction, after general site clearing and/or general
excavation, is to construct a keyway in which to build the rockery. The keyway shall comprise a shallow trench
of between twelve (12) and eighteen (18) inches in depth, extending for the full length of the rockery, and inclined
back slightly towards the face being protected. It is typically dug as wide as the rockery (including the width of
the rock filter laver).
If the condition of the protected face is of concern, the keyway should be constructed in sections of manageable
length, that is of a length that can be constructed in one shift or one days work.
The competency of the keyway subgrade to support the rockery shall be verified by probing with a small diameter
steel rod. The rod shall leave a diameter of between three -eights and one-half inch, and shall be pushed into
the subgrade in a smooth unaided manner under the body weight of the prober only.
Penetration of up to six inches, with some difficulty, shall indicate a "competent" keyway subgrade unless other
factors in the geotechnical engineer's opinion shall indicate otherwise. Penetration in excess of six inches, or of
that depth with ease, shall indicate a "soft" subgrade and one that could require treatment. Soft areas of the
subgrade can be "firmed up" by tamping a layer of coarse quarry spalls into the subgrade.
3.01.11 Ke=av and Rockery Drainage: On completion of keyway excavation, a shallow ditch or trench, approxi-
mately twelve (12) inches wide and deep, should be dug along the rear edge of the keyway. A minimum four -
inch diameter perforated or slotted ADS drain pipe, or equivalent approved by an engineer, should be placed in
this shallow trench and should be bedded on and surrounded by a free -draining crushed rock. Burial of the drain
pipe in this shallow trench provides protection to the pipe and helps prevent it from being inadvertently crushed
by pieces of the rockery rock. This drain pipe should be installed with sufficient gradient to initiate flow, and
should be connected to a positive and permanent discharge.
Positive and permanent drainage should be considered to mean an existing, or to be installed, storm drain system,
a swale, ditch or other form of surface water flow collection system, a detention or retention pond, or other
stable native site feature or previously installed collection system.
3.01.12 Rockery Thickness: The individual rockery thickness, including the rock filter layer, should be at least
40 percent of the rockery height. Unless otherwise specified in writing, the individual rocks should be arranged
in a single course which, when measured to include the filter layer, is equal to the required rockery thickness.
ii
3.01.13 Rock Selection: The contractor should have sufficient space available so that he can select from among
a number of stockpiled rocks for each space in the rockery to be filled. Rocks which have shapes which do not
match the spaces offered by the previous course of rock should be placed elsewhere to obtain a better fit.
Rock should be of a generally cubical, tabular or semi -rectangular shape. Any rocks of basically rounded or
tetrahedral form should be rejected or used for filling large void spaces.
Smaller rocks (one to two -man size, or smaller) are often used to create an aesthetically pleasing "top edge" to
a rockery. This is acceptable provided none of the events described in Section 3.01.5 occur, and that people are
prevented from climbing or walking on the finished rockery. This is the owner's responsibility.
3.01.14 Rock Placement: The first course of rock should be placed on firm unyielding soil. There should be full
contact between the rock and soil, which may require shaping of the ground surface or slamming or dropping the
rocks into place so that the soil foundation conforms to the rock face bearing on it. As an alternative, it is
satisfactory to place and tamp crushed rock into the subgrade to tighten it up. The bottom of the first course
of rock should be a minimum of twelve (12) inches below the lowest adjacent site grade.
As the rockery is constructed, the rocks should be placed so that there are no continuous joint planes in either
the vertical or lateral direction. Each rock should bear on at least two rocks below it. Rocks should be placed
so that there is some bearing between flat rock faces rather than on joints. Joints between courses should slope
downward towards the material being protected (away from the face of the rockery).
3.01.15 Face Inclination: The face of the rockery should be inclined at a gradient of about 1:6 (Horizontal: -
Vertical) back towards the face being protected. The inclination should not constructed flatter than 1H:4V.
3.01.16 Voids: Because of the nature of the product used to construct a rockery, it is virtually impossible to avoid
creating void spaces between individual rocks. However, it should be recognized that voids do not necessarily
constitute a problem in rockery construction.
Where voids of greater than six inches in dimension exist in the face of a rockery they should be visually examined
to determine if contact between the rocks exists within the thickness of the rockery. If contact does exist, no
further action is required. However, if there is no rock contact within the rockery thickness the void should be
"chinked" with a smaller piece of rock. If a void of greater than six inches exists in the rear face of the rockery,
it should be "chinked" with a smaller rock.
3.01.17 Filter Laver. In order to provide some degree of drainage control behind the rockery, and as a means
of helping to prevent loss of soil through the face of the rockery, a drainage filter shall be installed layer between
the rear face of the rockery and the soil face being protected. This filter layer should be at least twelve (12)
inches thick; and for walls in excess of eight feet in height, it should be at least eighteen (18) inches thick. It
should be composed of four inch minus crushed rock, or other material approved by the geotechnical engineer.
If one of the rockery rocks extends back to the exposed soil face, it is not necessary that the filter rock layer
extend between it and the soil face.
In the event seepage is encountered emanating from a protected face, we recommend the use of a well -graded
filter layer. We do not recommend the use of a geotechnical fabric for other than coverage of relatively small and
isolated seepage areas because it has been the industry's experience that the filter fabric tends to clog rapidly.
This quickly leads to a buildup of hydrostatic pressure which can subsequently cause failure and collapse of the
rockery and is to be avoided.
This clogging is apparently due to the virtual impossibility of achieving full contact between the soil face, fabric
and rock filter material. If full surface contact cannot be achieved, there is often a tendency for the soil materials
to flush from the protected face into the "pockets" in the fabric which leads to the aforementioned clogging.
5
3.01.18 Surface Drainage: It is the owner's responsibility to intercept surface drainage from above the rockery
and direct it away from the rockery to a positive and permanent discharge well below and beyond the toe of the
wall. Use of other drainage control measures should be determined on a case -by -case basis by the geotechnical
engineer prior to bidding on the project.
1/27/89
Gp ilLt.i( CU� So .
3.2 p F'v ro R
,235- �1Sgo
013 3-nrz_,
Consulting Engineers and Scientists
City of Renton
P.O. Box 626
100 S. 2nd Street
Renton, Washington 98057
Attention: Lawrence I Warren, City Attorney
Subject: Sunnydale Mobile Home Park
Slope Erosion
Renton, Washington
Dear Sir:
WARREN KELLOGG d!RBEr~
;JEAN & FONTES, r S.
December 12, 1994
File: 716OG
Ser: 94-616
As requested, Harza is pleased to provide the following results of our field
observations for the above mentioned slope failure. This letter report was requested by
Mr. Ronald I Straka, Engineering Supervisor Department of Planning/Building/Public
Works, City of Renton. The failure is located at the top of the west -facing slope which
forms the west side of the Sunnydale Mobile Home Park located off of Union Avenue SE.
Access to the location is provided by entering the mobile home park, turning left on the
first street from the entrance and continuing to the end of the drive to a gravel lane which
accesses the stormwater detention pond and the top of the Cedar River Canyon. The
distance from Union Avenue SE to the failure location is approximately 1,000 feet.
Location
The failure is located on the northwest side of a southwest trending ridge that forms
the low end of the mobile home park. The canyon crest is situated almost 280 feet above
the Cedar River Valley floor. The average slope in the vicinity of the failure is over 40
percent (City of Renton Map No. 370). The area above the bluff crest covered by the
mobile home park is approximate 12 acres in area and generally drains towards the
detention system location. During periods of high intensity rainfall, it is likely that
stormdrain collectors are overtaxed and runoff flows down the streets and over the bluff
crest. The point of failure observed is one of the low areas along this portion of the bluff.
Site Conditions
The failure is believed to lie wholly within the property of the mobile home park.
Eroded debris has broken the chain link fence bordering the Seattle City Light right-of-
way. An estimated 200 cubic yards of debris has been washed downslope. Structures
2353 130th Avenue N.E., Suite 200
Bellevue, Washington 98005
Tel: (206) 882-2455 Fax: (206) 883-7555
Plaza West 9600 S.W. Oak Street, Suite 350
Portland, Oregon 97223
Tel: (503) 244-6922 Fax: (503) 244-6914
12/L3�7U
City of Renton
December 12, 1994
Page 2
located within the area of possible influence consists of the mobile home park storm drain
located within 10 feet (upslope) of the top of the failure (scarp); a City of Renton high
pressure (100 psi), 12-inch diameter water main located approximately 10 feet upslope of
the failure scarp; a detention pond (privately owned) located 50 feet upslope of the scarp;
a City of Renton sanitary sewer main located about 180 feet south of the failure; Seattle
City Light powerline right-of-way with one tower located about 400 feet south and a
second about 500 feet north of the failure; and a high-pressure petroleum line located
within the power line right-of-way downslope of the failure approximately 100 feet. A
thrust block supporting the City's high pressure waterline is located about 20 feet north of
the scarp.
The importance of these facilities and their proximity to the erosion scarp reflect a
need for prompt repair of the failure. The method of repair is recommended for speed,
ready and permanent drainage of the adjacent slope and a high level of resistance to future
washouts within the immediate vicinity of the failure.
A garbage dumpster was washed into the failure when the slope gave way. The
dumpster had been located adjacent to the access road at the top of the slope. Conditions
prior to failure are unknown so it can not be ascertained whether the dumpster location or
operation contributed to the failure. The failure does not appear to be a top -of -slope
loading failure; therefore, in our opinion the dumpster was not involved in initiating the
failure.
Slope Conditions
The site observations found that the top of the Cedar River bluff is formed by soil,
construction debris, organics and random fill pushed over the edge during past
development. While much of the area is covered by blackberry brambles, a raised berm
has been partially erected along much of the bluff to prevent over -slope runoff of
stormwater. This effort has been only marginally successful. It is our opinion that the
failure is the result of over -bank stormwater flow and erosion. At the head of the failure
scarp and under the access road, a resistant conglomerate layer which has impeded erosion
is located at a depth of about four feet. This layer is underlain by a massive claystone
(glacial till) that is exposed to the lower end of the failure. There is no evidence of
landsliding-wedge failure or rotational failure.
The fill soils consisting of loose sand and gravel with large quantities of organic
debris which overly the in situ base materials are saturated. Within the failure zone the fill
soil is seeping groundwater at a rate of about 1/2 to 1 gallon per minute. Examination of
exposures along the bluff crest revealed that large amounts of fill, construction debris and
vegetation comprise the slope cover on the upper 35 feet of the bluff. This material when
saturated will be mobilized by the slightest disturbance.
City of Renton
December 12, 1994
Page 3
The City of Renton water main was not exposed by the erosion failure. Any
additional erosion resulting from more overflow of storm runoff has the potential for
eroding closer to the water main and increasing the risk of failure. The City should verify
the water main and thrust block location. Periodic inspections should be made to assure
that the failure is not enlarging until the site is repaired especially during periods of
rainfall.
Probable Cause of Failure
The probable cause of failure was saturation of the slope sediments triggered by the
overtopping of the slope by stormwater runoff coming from the mobile home park to the
east and from the access road from the south. Most of the runoff appears to have flowed
along the gravel access road from an overtopped stormdrain collector in the paved
roadway. A secondary cause of saturation may be subsurface seepage from the detention
pond. The conglomerate and sand layers overlying the massive claystone may form an
ideal seepage blanket.
Observations of the upper drainage area extended to the paved street within the
mobile home park. The drainage system collectors, manholes and downslope discharge
pipe were clean. There was no evidence of vegetation, sedimentation or debris which
could have impeded flow. Flow at the manhole adjacent to the detention pond was, by
visual observation, equal to the flow at the manhole located downslope in the power line
right-of-way. The storm drain system appeared to be fully operational at the time of our
visit. Surface soil scour on the gravel access road and the trail along the west side of the
detention pond indicated rather high volume and velocity flows.
The degree of saturation of the adjacent slopes could not be determined. The lower
powerline right-of-way is not soggy -indicating no excessive seepage. There is evidence of
recent (1-2 years) slope failures of a small scale both above and below the right-of-way.
No evidence of wedge or rotational slope failure was observed - no deep seated
failure. Rotational failure would have been likely to have occurred if a surcharge such as a
truck (dumpster) or massive groundwater saturation had occurred. Most movement on
these canyon walls are small progressive rotational failures and long, shallow mass
movement failures such as observed in this case.
Recommended Mode of Repair
Because of the site conditions just described, we are recommending that immediate
repairs be instituted. Repairs should be initiated by removal of the dumpster now wedged
in the failure channel. A chainlink fence should be secured across the bottom of the
erosion channel and quarry spalls end dumped into the channel from above. The 2-inch to
City of Renton
December 12, 1994
Page 4
4-inch rock should be allowed to flow downslope and lodge behind the chainlink fencing.
Backfll the channel to a height slightly above the present top -of -slope. No cleanout of the
channel is required.
This mode of repair will result in a high density (higher than adjacent soils) steep
sloped but well drained backfill. The loose pack will allow settlement of the rock mass
which should be accommodated by overfilling the top -of -slope. Seepage passages from
the adjacent bank will be provided and overbank flow will be slowed and filtered by the
rock mass. Slow percolation of surface runoifwill minimize future erosion. Also, in the
event that the detention pond is leaking at an excessively high rate, this rock filter will
provide a relief outlet.
The quality of quarry spalls need not be high. Black Rock Quarry or the andesitic
rock from Issaquah area which degrades slowly on exposure will be suitable. The
resulting fines will reduce flow velocities with time but the mass will still act as a
satisfactory drain.
In addition to this repair, we recommend that the gravel drive leading from the
paved road be regraded to slope eastward from the stormdrain manhole to the storm drain
collector in the street. If this is not feasible, install a collector northwest of the pond at the
bottom of the access road. The curb adjacent to the existing collector in the street should
be raised to confine street runoff more successfully. Elimination of this runoff and the
placement of quarry spalls in the failure zone will minimize future degradation of the
slope.
Closure
We recommend that the mobile home park retain a registered geotechnical engineer
to observe the site and provide recommendations to the owner regarding repairs.
Recommendations should be reviewed by the City and repairs supervised by the engineer
or his representative. We consider the above recommendations to be minimal but
sufficient for the site conditions. Site conditions at the mobile home park and along the
rest of the canyon crest are conducive to sporadic slope failures. Only expenditures of
large sums of money would reduce the risk to very low levels. Immediate protection from
additional erosion is essential.
Long term observation and reevaluation evaluation of the site is warranted because
of the proximity of several utility services. Observation of seepage from the base of the
erosion channel on a regular basis is recommended. Consideration of shallow observation
borings on the south and west side of the detention pond drilled to the depth of the
claystone (about 20 feet) is suggested. These borings would provide early warning of
saturation of the slope. In addition, these borings would provide soil parameters for a
slope stability analysis if distress is found in the future. Rotational failure of steep slopes is
City of Renton
December 12, 1994
Page 5
always a possibility and presence of the several utilities on this terrain constitutes a
significant long-term risk which can be minimized by maintaining drainage.
These procedures would be in the best interest of the City, mobile home park owners
and the petroleum pipe line owner. A cost sharing plan to accomplish this program would
be appropriate. However, the City is the most likely entity to carry out the task and
continue the observations into the future.
Very truly yours,
Harza Northwest, Inc.
d/e'
Ri rd I Bie
Principal Engineering Geologist
RJB/sdc
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"A Tradition
of Excellence"
STEWART TITLE COMPANY
OF WASHINGTON, INC.
CUSTOMER SERVICE
DATE: B TIME: TOTAL # OF PAGES `o
PREPARED FOR:
REGARDING:
Enclosed Please Find The Following Items Per Your Request:
Listing Package
Tex Information
Map
spy Deed/Contract/Mortgage
Owner/Address
—CC &R's
Prepard by:
Phone 343-1323 Fax: 343-1334
PLEASE REMEMBER TO SPECIFY STEWART TITLE COMPANY ON ALL YOUR
PURCHASE AND SALE AGREEMENTS
Thank you for givinq Stewart Title Company the opportunity to be of service.
nwnw.sa rn 1111PPa
The infanywion providod s not a moult ofb Tde Geamh end ie not beeed an a complete e+ernirveoon of the public reoordy
3ewert Title Company dlsclevris any liaoilq as to the surnriency ens/cr eaect of the documents desrnbed in the profile.
Stawaet This Company • 1201 Third Aranua, 62101K Seattle, WA 99'101 - (200) 112a-1040
9 /1 9:irs� SU 90�-31111 A .413.LS : K:11 : t6-8 -�i= AIS=,18 Lti3S
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CHII:llGc7't'1'fLE )NSURANC:t COWANY
moo N.E. ath nAnT, SUITE 11.60
arT.1.mm, xasxIMOTON 98006
*I117+ R1'.tX)IIIII;P 1kr'MRNT0 .
SUNNYDALE MORTLE HOME PARR
STATUTORY WARRANTY DEED
'i
'II I GRAh"IOIt
IINTnN avr.NU¢ COMPANY, A LIMITED PARTNERSHIP, A NASHINUTUN LInI710 PARTIIGROIITT r ( I
ror and in consldlrllltun ur j
TEN DOLLARS AND OTHER GOOD AND VALunsLG CONS:bERhTTON II
I
in hand paid, CVnvcyS and wai 1 anlf to I
9t1NNY0ALF MODII.r. NONE PARK, A CALIFWNIA GENERAL PART"390111P
i
the fnllawing Wxdbcd Mal catXe elluslAW in ILA;Qussty 14 IITNe Voile. ^r Watfi> rnC I
I
ARR ATTACHED RIDER NARKED "LXIITDIT 'A" Poll THE LNUA), DE9CttIPTS011 AND "M •Et123M TOe•
wR7cN Is aY TRIS Q9vvrf.MCF WE A PART'KEMP.
D;ucd: H.+rch 23, 1992
UNION AVENUE WMPANT 1
r 1
u . by
RIZR7+AD—F-W�A. �7TNERAL rAnTnr.r, o
q $TAIL Or wwxNOTom 00
COUNTY OF XING
V O� th. J�' A.y �r "ONi , 1992 before me, the anderal9rleA a Notary
o` a "'_
•� PvLI 1c, personally �Ppoared Riehar� P. T.,wnr<n and saL7.y C. Leman to Ina ltrtovn to be the
x genorAl par, �r U1110,1 Avenve Company, a Llelted 9arr.nornhio and acknowledaad the
nnLd instrument to be ene tree en nct and deed of •ald genwralparEnwrlla)
:or the unwe and purrvees thero,Y+iMoj Viffell+ n0 on oath I.Lated that thaY wre
e•.,thori—A tn o=acvte the as t�,1'4LCiNfi181rtt,.:o}I' half of ula partnaranip.
I ` 91,
w On mf h {U s„d �rf)ciol�eesS'haQS�a�lt,r.,,t>+e Aay anA year 11HL above written.
I
f"j/iJJ� 1 //y1. thy[ °�' N c
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LI!GAL DeSCAIP'CIOx
The land+rfrrrrn In is 011RICJ in Iht SIRIC Vf Wu1+IMg10n, COUnry d RING and Is desuibrd
t'
s, fntlmn,
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PARCEL Ai
1
4 ,
•reE NOuru¢6sr puu¢ruZ OF THE SOIITHY.AST QUARTER )! SECTION 26, 1VwHSn1Y 23 NORTH,
" I
RISNCS S, EAST, WILLAIQTTE NRPTRTAN, TN XIRG CDUNTY, WASMINCTOMI
'
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EXCEYT TH6 HuRTH 330 rAZT T1115REOF)
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TIr•*'IVEa Yt:N AN YASEHLTNT FOR INcRES6, EGRESS, UTILITIES AMU ROW rVRPOSRS OVER
„
THU HALT 30 FEET or THE NORTH JIM FRRT OF TILE NORTHEAST QUARTER 0► THE SOUTHEAST
•;�'� ,• ::, I
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QUAR:ER or EAID SECTION 161 AND
.
TOGETHER WITH AN EAS'dHBNT FOR CONSl'RUL7f'%o, REPLACING, 1tECOnSTRV01'IHC, IErPROV2MC,
RrpAIRIHr: AND UAINTAINING A ROAD FOR EMERGENCY VIIHICLL ACCXSS tTJIIIl, u::DLR nxD
• . ,; .;'..1
1' " �'
Acn000 TEAT MnTTOH or THE NORTH 330 FEET OF THE 190RTI:uAST QUARTER OF THE
•� ''� •'
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•' '�^"j,:'�,; '.•'':.'w• :•
SOUTHEAST (OUARTLR AMD THE SOUTHEAST QUAPTOR OF THE NORTHEAST QHAaTEa OF SAID
.
SECTION 16, DESCRIDED AS FULLUwSf
•
COKXItmCINC AT THK ROnT MST COR"YER OF SAID NORTH 330 FEET1
•:,�';..: • • 4 '•'
riaEMcn MORTIS O1 DIIOREEL 0e'43' 2A4T Ar.own THE W29T LINE OF SAID SURDIVISIDN
237.12 FaaT To THE TItUE P0119T Or. DDa1HR2NO;
a'i,-i,.;., ,:,.'.; ••;
TrrsNCE NORTH '!1 OLUY_as 04'2_' FAST Co"TIMVInn Tra7N0 r.ATn tTUR OR.aa M•RT TO THE
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SOUTHWEST CORNER OF SAID SOUTHEAST QUARTER Or "HE NORIHEAST QVARTERI
"s ••• "" - ;,
?YYNC2 NORTH MI OROAERS 02103' EAST A,IL)NC THE WEST LINE Of SAID UUOUIVI9IOM
;,,til•�';•;%,,yy''••' •,,,,,;�::'
•�ia'1
220. 00 POET,
,,Al;r r.'?hR. ,:,k;;'e�,;.,,'; L.:
THKNCL SOUTH NA DEGR1SE3 59'57' EAOT 30.00 PEET1
TREKCY SOUTH 01 DEORLES 01'U3_ wl':3T 327.0', rrtT;
THENCE' (aAR?R .10 DEGREES 21'45' WEST 16.5E FEET1
TltrNcr NORTH 90 DECRRRS SS'1'1n VRST 29.67 FEET TO THE TRUE POINT OF 3KINNIN01
EXCEP: ANY MOHILL Oil WUFAcTVRED MON73 LOCATED THcnEOMr
"'' '• ';•."'%;: , ., -: I• , 1..'''
THAT PORTION OF THE NORTH 330 FEET OF Twe NORTHEAST QUARTER OF THE SOUTHEAST
�'S':a`' ,as',„'•�
+
QUARTER OF SECTION 16, 2VeN6HIF 23 NORTH, RAHOD 5 HAGT, NILLANSTTZ 101727nTAN, IN
XING COUNTY, wASHINCT021, DESCRIBED AS ►OLL94st
1jEr1INMINO AT THE eOu2jjwEsT OcRwan or rATO WORTH 330 F27T1
� .'.;::n '. • ..'`' `, ..'.
:HENCE NORTH 1 DrOREE3 04'23" EA9? ALONO THE WL9T LIKE OF earn RIIRnIVISION 217.I2
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FEE T /
TucWrs AOIITH BB DEGREES 55137' FAST 29.47 FEET)
• ":
T1I11gDE SOUTH 30 D£OncEs 21'dS' RAaT 277.61 FEET TO THE SOUTH LINE OF THE NVMrN
..,. .. ..,. fi...i
330 FEET or EASO SUNDIVI92001
THENCE NORTH HY UEUYLES 00'3S" MUST ALOHO SAID DIN! 174.26 FERT TO TNI PIITHT f7F
BPOINNINGI
EXCrn ANY MOBILE Oa wANUFACPURrn NoMR.4 LOCATED TMERF,ON.
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weer. Vc,; 328n02
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' T&swxvN?, mNDR„NRD IN UN:TBD STATES DIAUICT COURT AIID TNi RRIa19 A11D' :''
CONDITIONS TRIAROV, +�'•::,, "'u'.• .".,.(,;;•
IN FAVOR vil UKITNO OTAT99 Or AHBnTcA
PORPOSR: ELx1;;TxIQ POWER TRANSMISSION LINGO,
AREA nrrscTCD,
CAU52 917wnvo.
ACCESS ROADS AND THE RIGHT TO CUr BRUSH
AND TPEES ADJOINING
A 200 FOOT STRIP Of LANn Argo" A
WZSTF_RLY PORTION OF nATM P"HIARL AND
OTHER PROPERTI
148
W6 VOTE ACCORDING TO DF.CRSB 9K'1'SRED OCTODER :, 17C8, IN RING OOVNTY
SUPERIOR COURT CAUSE NUMBER 86-2-0974E-6. THE OWNLR 01bAIU EASIMEIRT
OTftITS NAV CAUSE TO BE REMOVED OR DESTROYTD TNT SNIMXING POOL AND WAULNu
POOL LYING VITUIN THP FASEwP.NT VITA. .
EASEMENT A,,tJ TEE TERN5 AND CONDTTIONS THCAtOP,
CAANTFR• PUGET SOUND POWER 6 LIGHT :OMYANT
P•7ArO0Lr TAANaRTRSION LINE
AHGA Aerii'T'EDI T11A wr.CT 10 PERT Or THE BAST 79 r7rT of
PARCEL A
DRronorDI JUNE 29, 1946
nECOADINO NUODWR! 1593697
EASEMENT A3D THE TEAMS AND COND/TIONS Tns"url
GTtAN?E6,
OLYMPIC PIPE LINE COMPANY, A DELAWARH
.,:»q' :y�• ;wFMs,,..; r,,^.. 4i."Yyi'Y
k;``.'.,,'.:,.:a , , ...:. ,,
CORPORATIOY
•,': ,.
PURPOSE,
PIPELIKa POT( TELL^ TrLANSPOATATION OT OIL
;t
:';r;w `„' ::• , ':;d+;:" a,; '� ;JII
1,,.
AND CAB
..,
, y x r. •J ;K.�Si• �' .'•.
AI7TA ►PPS!'TPR.
A WISTERLY PORTION OF SKID PREMISIS
I
REOOR)ED:
rr R11I7ARY 14, 1973
RP.COROINU NUMBER:
75021406oa
LAG:.NLtIT, COwOBY.lICD IN r"a
cnnNTv RL'PC'AIOA CODA' AND :'HE TERMS AND
;ur'
�V'rDITIOTS 2MERlOT,
IN FAVOR OFI
CITY VF REKTOK
Dr1DDn.cr.,
SANITARY SEVER AND TRUNK LIKE
•.
An?A AFFECTED,
TRR EAST 30 FEETI TNT SOUTH 10 FEET OF
.- '' 1
•..
THE DOUTw 6o FIrT ANn Tfil• WRRT 100 PITT
;W.' •' ;
Of TItD QOUTH GO rEE7 0P 9AQ"..L A
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ran5f' NCHDeAI
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UNnFnCROVND UTILITY RA9rHF.NT
AN,) THR TERMS AND CONDITIONS THEREOF:
,
�',..•'I"`•,;..,
'•'•{'
•, .•.;I'•�'•"
GRANTEE:
QOUND r0•+En C LIOUT COMPANY
rURPOSE,
ELE(7L'x1C TRANSMISSION AND/OR DIDThIDl14'20N
/•'„ i
AnsA ArrrcrtM,
A RIGHT OF WAY 7 FEET TN WIDTH AS CONSTRTICTED
oR To al cow9TDUrTPD WITHIN PARCEL D AND
i
OTIIDR rnOPLRTY
• .
RECORDIC,
uVrODER 1a, 1171
, • .'
RwCORDING NUriBEP.,
7910180683
CONTAIN.^, COVENANT rAONIAITINC
v nEASEMENT
92AUCTUDrc 3 O 1[ to 2D OR OTHER
,
AL1'1V1TI1;3 WI12Cll MIC11T ENDANO'o'R
Tlln "Y'UnOROUND 9YA TRR-
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f
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9 /r -: U29 SEA 90�-11.11.1 INV.tKs : K: TT : M-8 -�T: Ks:Ag INNS
ZASEM"T AND THE TERMS
AND CONDITIONS TRZREQFI
OnANTIt
cj?v 0,., RENTON
PUBLIC OTILIT129 J!NrLf!nTV111 WATER AND SEWER)
WITH NEC933ARY ArPUnTtNhmCES
AREA AFFECTWDi
AS CONSTRUCTED ACROSS PARCEL 5 AND OTIMn
PROPERTY
RECORDCD;
XLUQKU,hQ NUMSSRI
7111190n93
eAqR74mmT AND THE 7p.rjM9
hNr) CONDITIONS TKEREO?t
GRAFT11.9 i
PLIGET 0OUND POWER I LICHT l!T)MVIKY
FURPOSRI
U"CTRIC TMNSM133loN AND DTCTfttAUTTON LIVE
ARTA Arp7mol
THE EAST 30 FRET Or rhkCEL A AMD h RIGHT Or
WAY 10 FEET IN WIDTH AS CONSTRUCTED OR IV NO
O*gSTpUcTrn Acnnt.Q A PORTION Or PWZL A
RECORDED1
CcTobgrl 31 1103
RECORDING NUMBERI
Tmr. Tp.7tmA
KNM MNDITToma TReltror,
PACIFIC NORTHWEST BELL TELEPHONE COMPANY
C"NTEE;
UNDERGROUND COKKUNICATXQN LLKSS
4
It-royo mp t.IvD 10 FEET IN WIbTR AS
ISTAbLISMfD ACK003 PARCEL A
RECOADEDt
NOVEMBER 3, ivej
RECORDING NUMBER:
831103092
XASLKENT ANU 'IMI; ISRM3
AND CONDITIONS THEREOPI
DISCLOSED BY:
DEED
Punposr,
vnAn FOR RM90C.RNCY VEMICLTS
hPr2CT3:
rAnCCL 5
k16GUNUxul
utCXXSER 29, 1983
EASEMEM-r An THE TERMS
AND CONDITIONS THEncor;
GRANTEEt
CITY OF RENTON
WITtO T.TMX WITH NECESSARY APPURTENANCES
AREA Arroafmo.
POnTIONO OF PAACAL A
Axwkb&u I
MAY 11, 1954
RECORDING NUMBER..
840SI10646
rA7rK911T AND THE TERMS
AND CONDITIONS T1ll!RtOr4
GRANTEE:
CITY OF RENTON
PURPOclpt
SANITARY SEWER WITH NECESSARY APPURTENANCES
AREA AFPrCTEDt
ACAUS rORTrONS op PARcrL A.
RECORDED i
MAY 11, 1904
RECORDING NUMBER:
84Qb110641
CA=Mr,rJT AND Tfir
CIANTFti
AND CONDITIONS THERGOr-
CITY Or RENTON
PURPOSEt
ROADWAY AND PUBLIC UTILITIEn WITH ncissm
XPPURTINANCES
AnvA AvrreTrn,
Tilt EAST 30 PIT? TUT 91,111TU in TPVT Awn Till
8OUT11 410.19 FEET Or THE W29T 30 FRET OF
PARCEL A
AECOPDKDi
FAY I I , 1904
trenRorNa NUMRFRI
8405110548
7w.
9 /S ;:TfsZ SEA 9H —11111 ISVMIIS : U:IT : t6-8 -�T:
MIS: Ao INNS
ariFl TAW
GRANTEE: CITY M RENTON •,I
I'Unt•OCE, WATER LINE WITM NtC556ART APPVRTENARCE9 �, •'.j
AREA AftaCTEDI A STRIP OF LAND 20 FEET IN WIDTH ACROSS A i
WESTERLY PORTION 0? SAID PREMISES !„ ,
RECORDED: NARCM 12, 1991
RECORDINO NUMBED. 0703130543
t
I
SAID EASEMENT SUPRRCRnRQ VkArwVMT RernRDED UNO[R URM&DINO NUM9?R 06I0111967.
1
. ezearssoNC. AND RE3ttRVATI4N9 CONiAlNlU IN DBND FROM THE STATE Of WASYINCTOft,
i
WHERYt1Y THE GRANTOR EXCEPTS AND RESERVES ALL OIL, GASES, COAL, ORES, MINERALS,
FOSSILS, ETC., AND THE RIGHT of ENTRY fUR ORCWTHO, nrvrtnotNr. Alan VAR[INn TRY
111
•
RAMP ANn ORnVIDINO TNAT SUCH AIOHT9 SHALL NOT BE pXEROICIID VNTIL PROVI010N ttAO
�
DEEP MADD MR PULL PAYMENT Of ALL DAMAGES 5USTAINED By REASON OF SUCH ENTRY;
�•,�>'•.•', �^ •'.+
RECORDED UNUKK RECORDING NURSER 6166392.
'�';'••'•'�'i '
nTRHT OF STATE 01 WASNINOTON OR ITS SUCCE680nb, 6UDJDOT TO TAYNI7NT OP
•;"':•7,t,
COMPENSATION THERItORE, TO ACQUIRE RIGHTS Ot WAY FOR PALVATE RAILROADS, SKID
ROADS, FLUXES, CANALS, WATER COURSES OR OTHER EASEMEIITS FOR TRANSPORTING AND
�-
MOVING TIMBER. STONY, MINERALS AND OTHIR runnrtr.Tn vPekm THT4 AND O'IMEit
'a
DRODERTY, f14 RES>tim:4 IN DYED AEPERPtto TO ADOV3,
HBSTRICTIONS CONTAINED IN INSTRUMENT AS HERETO ATTACHED,
P.RCORREOt LEPTBMDL"n 0, 1D03
RECORDING NUMBER, $309990705
r' • ' "� ;^��i%+iPi
RESTRICTIONS AND COVSNANT6 CCNTAINL'D IN AOREBMENT RDC11RDINO T1t$ U9E or THE
TRANSMISSION LINE, RIGHT or WAt, AS HEAETO ATTACHED,
•�"".''�°�ti' �;{
r!;'
Rr•.mRDEDe APRIL 4, 1994
�Y''�e,,.
RECORDI110 NUMBER,: 0404040630
•;!�
LCASK, AND THE TERMS AND CONDITIONS THEREOF, �•
'�1
t,> csnR, UNION AVENUE COMPANY
:I
L:
LEaeEE, ATKTManM WAlHCR 4P.2VICR, INC.-
tOR A TERM Of� YBARB CLUB B:ITENSI0118
RECORDED, rEBHVARI 22, 190a
!• y
RECORDING NUMBERt 8402220929
TH£ MonlLF IIOM6 OR MANUFACTURED HOME (AS DEFINED IN HCM 46.04.302) LOCATED OR
,�•�•;:,'
TO DD LOCATED ON THE ALA:, PROPi<R?v MRSCRIBF.D HEREIN IS SUBJECT TO LICENSING
AhU '1'1'Li.Y REGISTRATION AY THE DEPARTMRNT Of MOTOR VEHICLI9 Pt,RcitAHT TO RCN.
#
46.12.290.
" I
ANY LIEN AAISINC PRGM clipr. OR m,;vRASION OF USt OF A MOBILE HOME PARR AS
'.tr•;;�• '•,�
AUTHORIZED VNDER cHAPTDR 171, EESBION LAWS Or I99G, U!NATR SUBSTITUTE BILL N0.
2907 AND R.C.W. 5V,21.020, AS AMENDED.
tt tfdtiAO MIJ! IMSURAW.H COMPANY I
I
9 /9 9:lrs� 2U 90�-31111 IN .1lls : OC IT : M-8 -�I: 1ls--A8 lAas
CITY OF RENTON
MEMORANDUM
DATE: December 1, 1994
TO: Ron Olsen
FROM: Ron Straka��
SUBJECT: Sunnydale Mobile Home Park Slope Failure
The following is a list of immediate action taken to date in response to the above
referenced problem.
No.
ACTIONS TAKEN
DATE
WHO
STATUS
1.
Slope Failure Discovered. Threat to City
11/30/94
Wastewater
Done
Utilities assessed (water line). Steps
Maintenance &
taken to minimize risk to City Utilities
Surface Water
(shut water line down), Property and
Engineering
utility ownership researched.
2.
City Insurance Claims adjuster inspected
11/30/94
Wastewater
Done
site, information on potential claim
Maintenance &
prepared.
Claims
Adjuster
3.
Selected Harza NW from Annual
12/1/94
Surface Water
Done
Engineering Consultant Contract list to
Utility
investigate the cause of the slope failure.
Engineering
Transmitted letter requesting their
services. Set-up work order number to
track project costs (W.O.# 62011.
December 1, 1994
Page 2
4.
Met with Denny Mellott (206) 255-7503 of
12/1/94
Surface Water
Done
New Line Construction who was hired to
Utility
repair the slide by the Sunnydale Mobile
Engineering &
Home Park operator. More field
Wastewater
investigation is needed to determine if
Maintenance
the storm line has separated due to the
slide. Method to fix problem should be
designed by a P.E. Contractor will not
proceed until source of the problem and
a solution is identified.
5.
Contacted the Operator of the Sunnydale
12/1/94
Surface Water
Done
Mobile Home Park (375 Union Ave. SE
Utility
Renton Wa. 98059), Gail Roy, at 277-
Engineering
0165 to notify them of the problem,
recommend that they take temporary
measures to prevent the slide from
becoming worse, hire a P.E. to develop
engineering plans to fix the problem and
protect the City Utilities for our review
and approval, to contact neighboring
property owner(s) of slide and to take
12/2/94
Pending
steps to solve the problem. Conversation
followed up with a letter
6.
Field Inspect the downstream storm
12/2/94
All
Pending
system with Wastewater Maintenance,
Surface Water Utility Engineering Section
and Harza Northwest
ACTIONS.DOC/RJS
k
4.R wAL
Earl Clymer, Mayor
December 1, 1994
Albert Liou, P.E.
Senior Civil Engineer
Harza Northwest, Inc.
2353 130th Avenue NE - STE 200
Bellevue, WA 98055
CITY OF RENTON
Planning/Building/Public Works Department
Gregg Zimmerman P.F., Administrator
SUBJECT CITY OF RENTON ANNUAL CONSULTANT CONTRACT-SUNNYDALE MOBILE HOME
PARK SLOPE FAILURE INVESTIGATION
Dear Mr. Liou:
The City of Renton requests Harza Northwest, Inc. to perform consultant services in
accordance with the approved annual consultant contract. The work will be done on a
time and material's basis at the hourly rates established and agreed upon in the
approved annual consultant contract.
The scope of work includes investigating a slope failure at the Sunnydale Mobile Home
Park in Renton. Enclosed is a vicinity map. Construction plans showing existing
utilities (water, sewer and storm) located in the vicinity of the landslide will be
provided prior to your field investigation. The primary objectives of the investigation
should include, at a minimum, the following:
• Investigate and determine the cause of the slope failure
• Assess the stability of the slope
Assess the threat to existing utilities in the vicinity of the slope failure
Recommend methods for stabilizing the slope and protecting the existing
utilities
• Perform technical reviews of engineering plans to stabilize the slope.
Please provide an estimate of the cost associated with performing the above -
referenced work. We are interested in initiating the investigation as soon as possible,
since existing utilities are threatened by the landslide. If you have any questions
regarding this subject, please contact me at (206) 277-5548
yinrely,
Ronald J. traka, P.E., Engineering Supervisor
Surface Water Utility
H:DOCS:94-1094:RJS:ps
CC: Ron Olsen
Jack Crumley
Enclosure
200 Mill Avenue South - Renton, Washington 98055
TIIIS PAPER CONTAINS 50% RECYCLED MATERIAL, 10% POST CONSUMER
THE CITY OF RENTON
DEPARTMENT OF
PLANNING/BUILDING/PUBLIC WORKS
FOURTH FLOOR
200 MILL AVENUE SOUTH
RENTON, WASHINGTON 98055-2189
FAX: 235-2541
To: 1-1 o 0 4�'f!2--D
Company: /h5�eZ+4- /ViJ
Phone: gg2 -Z,5�5T
Fax: 91 32 _75f—
From:
Company:
Phone:
Fax:
Date:
Pages including this
cover page:
9)17
Cie 1�4- d /0,7 /-'-Yl
27 ?
Z3S = z S¢ l
2
Comments:
1-
w�� see- y6v Q
p2�
Ithol— A /'�- /'4 eo,- d7" /4� /-5
eP7 121Z /y i — % ' `
FINAL DECLARATION OF NON -SIGNIFICANCE
Application No(s):
Environmental Checklist No.:
Description of Proposal:
Proponent:
Location of Proposal:
Lead Agency:
PMH-045-83; FMH-046-83
ECF-038-83
Applications for preliminary and
final mobile home park approval
to allow development of a 203-lot
mobile home community,
comprising single and double wide
units on a 30-acre parcel to be
called "Sunnydale Mobile Home
Community".
Oakhurst Development
Corporation
Located on the west side of Union
Avenue S.E. at S.E. 4th Street,
and directly south of the "Leisure
Estates" mobile home park.
City of Renton Building & Zoning
Department
This proposal was reviewed by the ERC on July 6, 1983 and July 13, 1983, following a
presentation by Roger Blaylock of the Building & Zoning Department. Oral comments
were accepted from: Ronald Nelson, Paul Lumbert, David Clemens, Jerry Lind, Richard
Houghton, Robert Bergstrom, Roger Blaylock, Ed Wooten, James Hanson and Donald
Monaghan..
Incorporated by reference in the record of the proceedings of the ERC on application
ECF-038-83 are the following:
1. Environmental Checklist Review, prepared by: Richard F. Loman, DATED June 23,
1983.
2. Applications: Preliminary Mobile Home (PMH-045-83) and Final Mobile Home
(FMH-046-83).
3. Recommendations for a declaration of non -significance: Fire Prevention Bureau,
Police Department, Parks & Recreation Department, Building & Zoning
Department, Utility Engineering Division.
More information: Policy Development Department
Acting as the Responsible Official, the ERC has determined this development does not
have a significant adverse impact on the environment. An EIS is not required under RCW
43.21C.030(2)(c). This decision was made after review by the lead agency of a complete
environmental checklist and other information on file with the lead agency.
Reasons for declaration of environmental non -significance:
This final declaration of non -significance is issued subject to the following conditions
being complied with:
1. Payment of $6,000 to mitigate traffic impacts on the N.E. 4th Street
Corridors between Union Avenue N.E. and Sunset Boulevard N.E.
2. The applicant shall provide a positive outfall for storm water drainage from
the subject site to the Cedar River. This shall specifically include written
approval from the King County Department of Public Works.
st Final Declaration
1983
3. The applicant shall construct a five (5) foot wide, hard surface walkway from
the northern boundary of the subject site northward to N.E. 4th Street, and it
shall be specifically located on the east side of Union Avenue N.E. north of the
proposed plat of Fernwood North. The walkway is to be located and installed
in accordance with plans and specifications approved by the Department of
Public Works, said plans and the improvements to include necessary associated
drainage appurtenances.
4. Three basketball/sports courts with an average size of forty (40) feet by eighty
(80) feet shall be constructed in disperse locations throughout the mobile home
park.
5. The secondary emergency access issue shall be resolved prior to the public
hearing.
6. The property owner shall grant a perpetual easement to the City of Renton for
roadway and utility purposes over the following parcels:
a. The southern thirty (30) feet of the subject site.
b. The eastern thirty (30) feet of the subject property adjacent to the City
of Seattle property.
C. That property located in the southwestern corner of the subject site,
which lies underneath the powerlines and south of the northern margin of
the western access road as shown in revised plans received by the
Building and Zoning Department on June 24, 1983. (The property owner
shall bear the total cost of relocating any recreation facilities, when the
roadway is finally constructed.)
SIGNATURES:
Id G. Nelson
ing and Zoning Director
R%hard C. Houghton
Public Works Director
PUBLISHED: July 18, 1983
APPEAL DATE: August 1, 1983
David R. Clemens
Policy Development Director
39
ENVIRONMENTAL CHECKLIST REVIEW SHEET
ECF - 038 - 83
APPLICATION No (s) : PRELIM. MOBILE HOME PK. (PMH-045-83)FINAL MOBILE HOME PK. (FMH-046-8
PROPONENT: 0A1QRITLFZP Df--.Vl-:T,OPMFW MRPORATTON
PROJECT TITLE: SUNNYDALF. MOBILE HOME JNITY
Brief Description of Project: APPLICATION FOR PRELIMINARY MOBILE, HOME : PARK
APPIWAL TO ALLOW DLVL; D1M--Xr OF A 2 - Bim. HOME octt JNITY, COI�RISING SIIa LE
AND DOUBLE WIDE UNITS ON A 30 ACRE PARCEL.
TfiE PROPERTY IS LOCATED ON THE WEST SIDE OF UNION AVE. S.E. AT S.E. 4th S'I'.,
LOCATION: AND DIRECTLY SOUTH OF T9IE "LEISURE ESTATES" MOBILE 1 K1% - PARK.
SITE AREA: 30 ACRES BUILDING AREA (Gross): -
DEVELOPMENT COVERAGE (t): -
1)
2)
3)
4)
5)
6)
7)
8)
IMPACT REVIEW NONE MINOR MAJOR MORE
INFO
Topographic
Direct/Indir
Water & Wat
Plant Life:
Animal Life:
Noise:
Light & Glar
Changes:
ect Air Quality:
er Courses •
X
X
X STORM
X
X
X
e:
X
Land Use; North:
MOBILE HOME PARK
East : SINGLE FAMILY RESIDENTIAL
South: UNDEVEI,OPID
West: UNDEVELOPED
Land Use Conflicts: MINOR
View Obstruction: MINIMAL
9) Natural Resources:
10) Risk of Upset:
11) Population/Employment:
12) Number of Dwellings: 203
X
X
X
X
13) Trip Ends (ITE):
Traffic Impacts:
14) Public Ser
15) Energy:
16) Utilities:
17) Human Heal
18) Aesthetics:
19) Recreation:
20) Archeology/
vices : X FIRE
X
X
the X
X
X
History: X
Signatures:
C. Cc
Robald G. Nelson tMvid R. Clemens
j Building & Zoning Director Policy Development Director
Richard C. Houghton.,'
Public Works Director
PUBLISHED: JULY 18, 1983
APPEAL DATE: AUGUST 1, 1983
:SS
0-81
Signatures:
C. Cc
Robald G. Nelson tMvid R. Clemens
j Building & Zoning Director Policy Development Director
Richard C. Houghton.,'
Public Works Director
PUBLISHED: JULY 18, 1983
APPEAL DATE: AUGUST 1, 1983
:SS
0-81
THE CITY OF RENTON
DEPARTMENT OF
PLANNING/BUILDING/PUBLIC WORKS
FOURTH FLOOR
200 MILL AVENUE SOUTH
RENTON, WASHINGTON 98055-2189
FAX: 235-2541
To: Richard Bielefeld
Company: Harza NW U
Phone: (206) 882-2455
Fax: (206) 883-7555
From: Ronald J. Straka, P.E. ��
Company: City of Renton
Phone: (206) 277-5548
Fax: (206) 235-2541
D, 87(0101
Date: 12/09/94
Pages including this
cover page: 4
Comments:
Richard: Enclosed are my review edits regarding your report on the Sunnydale Mobile Home Park slope
erosion. Please review and call me if you have any questions regarding my comments. The
following is a summary of my comments:
1. Transmit the report to me via the City Attorney's office: Lawrence J. Warren, City Attorney; City of Renton;
Post Office Box 626 - 100 S. 2nd Street; Renton, Washington 98057.
2. The storm system on the Mobile Home Park is a private storm system owned by the property owner.
3. Note that the high pressure water main is a City of Renton water main.
4. The Water Utility has performed a Utility Locate on the water line. The water line is approx. 10 feet from the
start of the scarp and a thrust block is approx. 20 feet north of the scarp.
5. Note that the Mobile Home Park's detention facility is private storm facility. the sanitary sewer main is a City
of Renton facility.
6. If you feel that you can, the report should include information on the field observations about the on -site and
offsite storm system. For example "The storm system on the mobile home park property and the storm
system offsite did not appear to cause the slope erosion and appeared to be operational during the site
observation visit."
7. The report doesn't mention any thing about the garbage dumpster. It should be noted in the Site Conditions
section. Could have the fact that the dumpster was located exactly where the slope failure occurred
contributed to the failure (additional weight of the dumpster and live loadings due to a garbage truck
accessing the top of the slope to collect garbage from the dumpster? If so, mention in the Probable Cause of
Failure section.
8. If you can, please include a discussion about the water main and any recommendations of follow-up actions
that the city should take (see edit comments on your report).
9. Dan Carey doesn't think that the road can be regraded to drain in the opposite direction due to elevation
differences. A new catch basin connected to the existing storm system at the bottom of access road may be
more feasible (see edit comments on your report).
10. The City will have to require the property owner to hire a registered geotechnical engineer to develop a letter
report with repair details showing how the repair will be accomplished for our review and approval. we will
also probably want the engineer to supervise (be present) during the construction of the repair to make any
necessary field design changes. You may want to include some of this in your Closure section of the report.
11. In your long term evaluation, are you suggesting that the City do this? If so, please indicate.
12/05/94 16:15 FAX 206 883 7555 HARZa NW [a001
NORTHWEST, INC. Engineers and SdentiSts
From: A. J , )g,' e /r � lo(
2353130th Ave. N.E.. Suite 200
Bellevue. Washington 98005
FAX: (206) 883-7SSS (206) a52.2a55
Project: /s /p_ I'4I��.�rr �k
Charge # N q 4 13 3
Operator
MESSAGE
1.6
File:
Date: / 2 - s --9 4
.: T ::::::T L::.:
To Fax* C o 6 23 -i 2 — 4/
AttendoR — A uk41d J, S ,.r u 4
Company, C to
Page of
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Post -it "routing request pad 76"
ROUTING - REOUEST
Please
❑ READ To-
�
❑ HANDLE
❑ APPROVE ll 24—
and
❑ FORWARD v� A
❑ RETURN ` \
❑ KEEP OR DISCARD
❑ REVIEW WITH ME
rh t
o
Date �—
r
12/05/94 16:16 FAX 206 883 7555 HARZA MV
16002
Consulting Engineers and Scientists
December 5, 1994
City of Renton
200 NO Avenue South File: N941331P
Renton, WA 98055 Ser: 94-616
Attention: Ronald I Straka, P.E., Engineering Supervisor
Subject: Sunnydale Mobile Home Park
Slope Erosion
Renton, Washington
Dear Sir. -
As requested, Harza is pleased to provide the following results of our field
observations for the above mentioned slope failure. The failure is located at the top of the
west -facing slope which forms the west side of the Sunnydale Mobile Home Park located
off of Union Avenue SE. Access to the location is provided by entering the mobile home
park, turning left on the first street from the entrance and continuing to the end of the
drive to a gravel lane which accesses the stormwater detention pond and the top of the
Cedar River Canyon. The distance from Union Avenue SE to the failure location is
approximately 1,000 feet.
Location
The failure is located on the northwest side ofa southwest trending ridge that forms
the Iow end of the mobile home park, The Canyon crest is situated almost 280 feet above
the Cedar River Valley floor. The average slope in the vicinity of the failure is over 40
percent (City of Renton Map No. 370), The area above the bluff crest covered by the
mobile home park is approximate 12 acres in area and generally drains towards the
detention system location. During periods of high intensity rainfall, it is likely that
stormdrain collectors are overtaxed and runoff flows down the streets and over the bluff
crest. The point of failure observed is one of the low areas along this portion of the bluff.
Site Conditions
The failure is believed to be wholly within the property of the mobile home park. �5dn4ya&/'
Eroded debris has broken the chain link fence bordering the Seattle Light right-of-way.,,,
An estimated 200 cubic yards of debris has been washed downslide. Structures located
within the area of possible influence consists of the GStorm Drain located
within 10 feet (upslope) of the top of the failure (scarp); a*gh pressure (100 psi), 12-inch
2353 130th Avenue N.E., Suite 200 Plaza West 9600 S.W. Oak Street, Suite 350 CI U Bellevue, Washington 98005 Portland, Oregon 97223
Tel: (206) 882.2455 Fax: (206) 883-7555 Tel, (503) 244-6922 Fax: (503) 244-6914
•12/05/94
16:16 FAX 206 383 7555 HaRZA NW
City of Renton
December 5, 1994 Ito,
Page 2
12
diameter water main located approximately 30 feet upslope of the failure scarp, the mobile
home park)idetention pond located 50 feet upslope of the scarp; avianitary sewer main
located about 180 feet south of the failure; Seattle City Light powerline right-of-way with
one tower located about 400 feet south and a second about 500 feet north of the failure;
and a high-pressure petroleum line located within the power line right-of-way downslope
of the failure approximately 100 feet.
\,
Slope Conditions
The site observations found that the top of the Cedar River bluff is formed by soil,
construction debris, organics and random fill pushed over the edge during past
development. While much of the area is covered by blackberry brambles, a raised berm
,�1 N
has been partially erected along much of the bluff to prevent over -slope runoff of
Z�
stormwater. This effort has been only marginally successful. At present, the failure zone
is the result of over -bank stormwater flow and erosion. At the head of the failure scarp
�
and under the access road, a resistant conglomerate layer has impeded erosion at a depth
a
of about four feet. This layer is underlain by a massive claystone (glacial till) that is
exposed to the lower end of the failure. There is no evidence of land sliding -wedge failure
�h
or rotational failure.
The fill soils, loose sand and gravel with large quantities of orgaiuc debris, overlying
the in situ base materials are saturated. Within the failure zone this soil is seeping about
1/2 to 1 gallon per minute. Examination of exposures along the bluff crest revealed that
N.
large amounts of fill, construction debris and vegetation comprise the slope cover on the
upper 35 feet of the bluff. This material when saturated will be mobilized by the slightest
disturbance.
Probable Cause of Failure
The probable cause of failure was saturation of the slope sediments triggered by the
overtopping of the slope by stormwater runoff coming from the mobile home park to the
1�.
east and the access road located to the south. Most of the runoff appears to have flowed
along the gravel access road from an overtopped stormdrain collector in the paved drive
\
upslope. A secondary cause of saturation may be subsurface seepage from the detention
\
pond. The conglomerate and sand layers overlying the massive claystone may form an
ideal seepage blanket for this location.
$�
The degree of saturation of the adjacent slopes could not be determined. The lower
powerline right-of-way is not soggy -indicating no excessive seepage. There is evidence of
recent (1-2 years) slope failures of a small scale both above and below the right-of-way.
Z 003
12 /05 /94 16 : 1 i FAX 206 88.1 555 HARZA tilt'
Z 004
City of Renton
December 5, 1994
Page 3
No evidence of wedge or rotational slope failure was observed - no deep seated
apt° joy h 4V ',,,failure. Most movement on these canyon walls are small progressive rotational failures
and long, shallow mass movement failures such as observed in this case. j ``- L�
w" ,fie. C,+i of ��o.� ,ram _k�. vn .� i v4t e.. „p l?j jw J�veke %Jell cPJIJ l� �"``•tn"'J
ty -f7 .•i. `r�,� G,+y s� .,�J �n.,�.j r� tie �,�. of r+�- w-4f- ,n,..—
�( Recommended Mode of Repair
G i r-y �i� chi sE �,., . � /7� 7�C-.- �✓, ,Fi .+V+ .., 6 �u r� �.f..saw ..r . n
Because of the site conditions just described, we are recommending that minimal but
immediate repairs by instituted. Repairs should be initiated by removal of the dumpster
now wedged in the failure channel. A chainlink fence should be secured across the bottom
of the erosion channel and quarry spalls end dumped into the channel from above. The 2-
inch to 4-inch rock should be allowed to flow downslope and lodge behind the chainlink
fencing. Backfill the channel to a height slightly above the present top -of -slope. No
cleanout of the channel is required.
This mode of repair «•ill result in a high density (higher than adjacent soils) steep
sloped, well drained backf.11. the loose pack will allow settlement of the rock mass which
should be accommodated by overfilling the top -of -slope. Seepage passages from the
adjacent bank will be provided and overbank flow will be slowed and filtered by the rock
mass. Slow percolation of surface runoff will minimize future erosion. Also, in the event
that the detention pond is leaking at an excessively high rate, this rock filter will provide a
relief outlet.
The quality of quarry spalis need not be high. Black Rock Quarry or the andesitic s 2�
rock from Issaquah area which degrades slowly on exposure will be suitable. The � �� "I.
resulting fines will reduce flow velocities with time but the mass w611 still act as a ��,«� t '�i
satisfactory drain. �' "'1
In addition to this repair, we recommend that the gravel drive leading from the
paved road be regraded to slope eastward from the stormdrain manhole to the storm drain ,e
collector in the streetx All R;s z S `1 { �u I I°r
,^ 1hC� rorJ ,1a �,vyx«- l n^� — Elww�e' 0
'iv^bfF t^4o -N..� ��ar...� SY�fc�no-�„vS, k1.11 '�rt,ve I'�JV►O � r+,r
Closure�+ar+ fA- . ht f�owi..' over a•vp po �n r� 5+�� �l t c�.�cf ro•d .
�e
We recommend that the mobile home park retain a registered geotecluucal engineer ° P "^ • t
to observe the site and provide recommendations to the owner regarding repairs. We �' H" - S-
consider the above recommendations to be minimal but sufficient for the site conditions. G rofI ►p• d
Site conditions at the mobile home park and along the rest of the canyon crest are �wc�
conducive to sporadic slope failures. Only expenditures of large sums of money would
reduce the risk to very low levels_ Immediate protection from additional erosion is
essential.
l4Y- M,a�r J k�,� �,� <<ry zcv��N c svf.�n� �>+�l•.c%,��
12/05/9.1 16:17 FAX 206 883 7555 HARZA : tit' Z005
City of Renton
December 5, 1994
Page 4
Long term evaluation of the site is warranted because of the proximity of several
utility services_ Observation of seepage from the base of the erosion channel on a regular
basis is recommended. Consideration of shallow observation borings on the south and
west side of the detention pond drilled to the depth of the claystone (about 20 feet) is
suggested. These borings would provide early warning of saturation of the slope.
Rotational failure of steep slopes is always a possibility and presence of the several utilities
on this terrain constitutes a significant long-term risk which can be minimized by
maintaining drainage.
Very truly yours,
Harza Northwest, Inc,
Richard J. Bielefeld
RJB/sdc