HomeMy WebLinkAboutSWP273260 PROJECT REQUEST FORM
PLANNING/BUILDING/PUBLIC WORKS
DATE: 2-2 7-0 r CONTACT: l`7l - EXT.
FILE STATUS '4 NEW OR ❑ EXISTING: FILE CODE(PRI-xx-xxxx):
LOCATION My Work Space: ❑ File Bay Shelf#: 0 Other:
PROJECT NAME/FILE MLE: I We,e t1i e w C,� 7
(70 characters max)
DESCRIPTION OF rP� jROJECT: 1
UTILITY PERMIT# D LUA# D `f—�,3 / W O#
ADDRESS/-/STREET NAME(S): 3/La [�1Nc= 4^-O ccw'� L Al—,=
DEV: C l�1F I„)il rw►,S CNTR: ;OWN: ;CNSLT/ENG:_ C/>�jt/ �
OTHER ALIASES: ENS
Circle Size of Waterline: 10" 12" Circle One: New/Replace/Extension
Circle Size of Sewerline: 10" 12" Circle One: New/Replace/Extension
Circle Size of Stonnline: 1 S" 24" Circle One New/Replace/Extension
CHECK EACH DISCIPLINE INVOLVED IN PROJECT Ltr Drwg #of sheets
f� TED
(off site improvements) (inc ude TESC)
❑ TRO 0 0
(Signalization,Channelization,Lighting)
WWP ❑ 0
(sanitary sewer main,include basin naur)
WTR 0 0
(Mains,Valves,Hydrants) (inc.composite&HorizontalCtrl)
� swP da 0
(CIP only)(include basin name)
NA PLR (For Developer Files Only) (letter only)
PLEASE CIRCLE THE DISCIPLINES WHICH NEED TO SIGN MYLARS
WATER WASTEWATER SURFACE WATER TRANSPORTATION FIRE
FOR FILE htAIN`rAINANCE USE ONLY
File Codes File Alias Date Entered and Labels Made
_
�hf Ev
7-. 40 3a
American Engineering Corporation
`— Engineers Planners • Surveyors
Tech
nical Information Report
"Ridgeview Court"
' pity of Denton
Project Site Location:
327 Bremerton Avenue NE
Renton, NVA
May 12, 2005
Prepared For:
Ridgeview Court LLC
' /o: Ch Ef Williams
P.O. Blox 2401
Consulting Enyinccrs Kirkland, wa. 98033-2401
' Creative Solutions. . .
' Superior Service
AEC Job #0312
Ridg eview Court
Technical Information Report
City of Renton
Project Site Location:
327 Bremerton Avenue NE
Renton, WA
' Prepared For:
Ridgeview Court LLC
c/o: Cliff Williams
P.O. Box 2401
Kirkland, Wa. 98083-2401
Prepared By:
' American Engineering Corporation
Rob Stewart, E.I.T. / Cheryl Girard, P.E.
' May 12, 2005
J
5�
AEC Job No. 0312 C EX?iRES 0=-U5-2GG5—_1
King County Department of Development and Environmental Services
' DRAFT TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND
' PROJECT ENGINEER DESCRIPTION
Project Owner: Ridgeview Court LLC Project Name: Ridgeview Court
Address: c/o: Cliff Williams Location: Renton, Wa. (King County)
P.O. Box 2401
Kirkland, Wa. 98083-2401 Township: 23 North
Phone: (206) 933 - 1049 Range: 5 East
Project Engineer: Einar Gundersen NW '/< Section: 15
' Company: American Engineering Corp.
Phone/Address: (425) 881-7430
4032 148 nAvenue NE
Redmond. Wa. 98052
' Part 3 TYPE OF PERMIT Part 4 OTHER REVIEWS AND PERMITS
APPLICATION
❑ Subdivision ❑ DFW HPA ❑ Shoreline Management
' ® Short Subdivision ❑ COE 404 ® Rockery
❑ Grading ❑ DOE Dam Safety ® Structural Vaults
' ❑ Commercial ❑ FEMA Floodplain ❑ Other
❑ Other: ❑ COE Wetlands
Part 5 SITE COMMUNITY AND DRAINAGE BASIN
Community:
Newcastle Community Planning Area
Drainage Basin:
Cedar River Basin and Lower Cedar River Sub Basin
1
Part 6 SITE CHARACTERISTICS
❑ River ❑ Floodplain
❑ Stream ❑ Wetlands
❑ Critical Stream Reach ❑ Seeps/Springs
❑ Depression s/SwaIes ❑ High Groundwater Table
❑ Lake ❑ Groundwater Recharge
❑ Steep Slopes ® Other THIS SECTION N/A
Part 7 SOILS
Soil Type Slopes Erosion Potential Erosive Velocities
AqC 6%-15% slight to moderate medium
Additional Sheets Attached
Part 8 DEVELOPMENT LIMITATIONS
REFERENCE LIMITATION/SITE CONSTRAINT
® Level One Downstream Analysis
' ❑ See Section 3 for more details
❑
' ❑ Additional Sheets Attached
Part 9 ESC REQUIREMENTS
MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION AFTER CONSTRUCTION
® Sedimentation Facilities ® Stabilize Exposed Surface
® Stabilized Construction Entrance ® Remove and Restore Temporary ESC Facilities
® Perimeter Runoff Control ® Clean and Remove All Silt and Debris
' ® Clearing and Grading Restrictions ® Ensure Operation of Permanent Facilities
® Cover Practices ❑ Flag Limits of SAO and open space
® Construction Sequence preservation areas
' ❑ Other— ❑ Other
' Part 10 SURFACE WATER SYSTEM
❑ Grass Lined ❑ Tank ❑ Infiltration Method of Analysis
Channel
® Vault ❑ Depression 1998 KCSWDM
® Pipe System
❑ Energy Dissipator ® Flow Dispersal
❑ Open Channel
❑ Wetland ❑ Waiver
❑ Dry Pond
❑ Stream ❑ Regional
❑ Wet Pond Detention
Brief Description of System Operation: Runoff from the road way improvements roof areas and
yard areas will be collected and conveyed to the detention facility, and released at predeveloped
release rates per the City of Renton requirements Water Quality treatment will be provided in the
form of dead storage located below the live storage within the detention vault
Facility Related Site Limitations
Reference Facility Limitation
i
1 Part 11 STRUCTURAL ANALYSIS Part 12 EASEMENTS/TRACTS
® Cast in Place Vault ® Drainage Easement
❑ Retaining Wall ® Access Easement
® Rockery > 4' High ❑ Native Growth Protection Easement
1 ❑ Structural on Steep Slope ® Tract—Storm Drainage
❑ Other ® Other— Sewer Easement
Part 13 SIGNATURE OF PROFESSIONAL ENGINEER
I or a civil engineer under my supervision my supervision have visited the site. Actual site
conditions as observed were incorporated into this worksheet and the attachments. To the best of
' my knowledge the rmation provid ere is accurate.
Signed/Date
I
1
' TABLE OF CONTENTS
SECTION 1 PROJECT OVERVIEW...................................................................................................1
Figure1: Vicinity Map............................................................................................................................................2
Figure2: Site Map...................................................................................................................................................3
SECTION 2 CONDITIONS & REQUIREMENTS SUMMARY.......................................................4
SECTION 3 OFF-SITE ANALYSIS.....................................................................................................7
Figure3: Existing Conditions Map.........................................................................................................................8
Figure 4: Upstream Contributing Area Map...........................................................................................................9
Figure5: SCS Soils Map.......................................................................................................................................12
Figure6: Downstream Flow Map.........................................................................................................................14
Figure7: Downstream System Table.....................................................................................................................15
iSECTION 4 FLOW CONTROL& WATER QUALITY ANALYSIS AND DESIGN..................16
Figure8: Developed Conditions Map...................................................................................................................17
SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN..............................................25
SECTION7 OTHER PERMITS.........................................................................................................28
SECTION 8 ESC ANALYSIS AND DESIGN....................................................................................29
SECTION 9 BONDS SUMMARIES AND CO
VENANTS.................................. ...................31
SECTION 10 OPERATIONS AND MAINTENANCE MANUAL 2
1
t
American Engineering Corporation Page i
APPENDIX A
King County Community Planning Area Map
' King County Drainage Basin Map
Table 3.2.2. - Soil Types
Drainage Complaint List
APPENDIX B
Wetland Study by Alder NW dated March 13, 2003
APPENDIX C
Geotech Report by GeoGroup Northwest dated October 4, 2004
APPENDIX D
Rainfall Regions and Regional Scale Factor
Figure 5.3.4H from KCSWDM, riser inflow curves
King County Back Water Excel Spread Sheet
King County Back Water Outputs (Systems 1 to 8)
1 APPENDIX E
Operation and Maintenance Manual
' American Engineering Corporation Page ii
1 Technical Information Report for Ridgeview Court Mav 12, 2005
' SECTION 1 PROJECT OVERVIEW
' Project:
Ridgeview Court
1 AEC Job No. 0312
' Site Information:
1 The proposed project is to subdivide approximately 2.4 acres into 20 single-family
residences. The rectangular site is located within the City of Renton at 327 Bremerton
Avenue NE (KC Parcel No. 5182100042), see Figure 1: Vicinity Map. More
' generally, the site is located within the Northwest Quarter of Section 15 of Township
23 North, Range 5 East, W.M. The site is bordered by undeveloped parcels containing
single family residences to the north, south, and west, Bremerton Avenue NE to the
east, and the Post Office to the northwest.
Pre-developed Site Conditions:
The site contains a single-family residence, two detached buildings, and a gravel drive.
1 The single-family residence and detached buildings will be demolished as part of this
project. Runoff patterns for the site are generally from northeast to southwest with
slopes ranging from 2% to 25%. Ground cover on-site consists of pasture on the
southern portion of the site and forest on the northern portion on the site.
Post-developed Site Conditions:
The proposed development consists of 20 single-family lots with associated roads and
utilities and a separate tract for the stormwater detention facility, see Figure 2: Site
Map. Runoff from the roofs, driveways, upstream areas and frontage improvements
1 will be collected and conveyed to the stormwater detention facility and released at
predeveloped rates per the City of Renton requirements.
1
I
1
American Engineering Corporation Page 1
w
NE_. z a< LNE
r i!y,�s n' a12
T ,Sirs 0. 'A,J .} SJ < ..STM 9f NF S7H T M ST_ $IT s f � a REf?QN W y..4c � HEa TECRNICAL � 4ALC
' iTIH CT NE COLLEGE 4TH Q "' ST ..
GREENWOOD
N,
S z 140ORIAL ¢ NE 3RD CT, SE 129
PARK N- Pua'Siff),?NO PL'
NE 2ND ST NE E \3!s!y~ 132ND
_ .. - w 2N0 ST i
� i "SITE sF .1.7RD 5t
CTW N !sr sAf ;
LEISURE ¢' ham. t 5E 134TIl_'.
'� 0 51
.. SE
ESTATES :SE.IS! PLy�;_ � - 1 5TI4 SE
� - p,Y -
M P � T l35TI1
Wp3�s I.. ST n Sr
SE I 2ND Z. PL SE _ 136THsr
x st a I
SURRYUALE, SE SE 13BTH-_SL_
MWP "" Q� rwi
SE 411{ 'p AZN sf a
W Y s^s r <
SE _, 57H SE st
...Jf 6)H S'E ,ELIPLEMQiD L_�. yr
av 14157
Qo se 'A .PARK y
'VERVIEN !Krt[Wcn ST a
PARK as>se vase $ � � 142NO ST
c� !< SE
H-.
41 'K^ �Sr o;n
� SF!I
VICINITY MAP
' (NOT TO SCALE)
1
American Engineers • Planners • Surveyors R I D G EV I EW COURT
Engineering 4032 148th Ave. N.E.
Corporation Redmond. WA98052 VICINITY MAP
PHONE (425\881^ePY nG % 8.d 773 � PDT PROJECT NUMBER GATE SCALE FIGURE
\2003\0312 E g g\Dw g\E03l2FGlr g 10/OV200a 09-43 31 AM 0312 07-20-04 AS NOTED 1
NE 4th ST
_ N88'06'17"W 323.52'
90 18' 50 50'
90
C4 y) N
{ 90, n m 0 at I NO m � 25 30'
-+ i
01 1 1 16'
90'
a 50' 50'
CDN CDN L V
-�00 OA BOA � OU
T� 90' CDN I rmv ymv a�o
rn( N r00 I �< 20 mN< Of
-im�_a DDD Daa
�< I ImOy m0
aDn eDT� I �I NZ~ mZm J mZm W \\
rN•10m 111 mom Z y
90' Z ss
a, m
z 2b, ° 00
y Z M
o o� o
'Pa 59'
"�� I O
vs, 'y i' 96• 6' J I Z
ROAD "A" N
e D
I C
o p' n N C4 m
L4
107' p.
x
65
55' AA
CA
90'
20
_ nwi- I I M X r, 00 u I 50' 4+
> 50
` I '—i CDN CDN 90•
o '
m -m
-I 'D y 11
CAA jN<
x v y D D 01 rn D a a
��N*70i � m 0
-- NZt�
a
x Z L
Z N ��_65w61 S0' _- 9•���
M< N88'09'35"W 323.83 - ———
ma �I
m
r mo cA
M m my �-a
Z MCD AC y< I
a� ma
m
Dm
m s
z m
'1 Z
O
QD
x Q
Date
� O(5 IIr
1
O
RIDGEVIEW COURT 07 20 04 No ReNelone y
CHRIg7, . • Date 8
t-4 �¢�•ot'*Asti Frd American Engineers Planners Surveyors Scale AS SHOWN
p SITE MAP �:�� �a: Engineering 4032 1IM_401h Ave.NE.
Corporation Ro52 Q DfO- NEB
-
a44 'a"/ _ Designed
�' �`PS/Rb{aTSP,44y�• PHONE(425)881-7430 Fax(425)881-7731 RWS
O/✓AL LP,
E)OnVE3 DUET 30. Flte path$Noma Checked EG
PA2003\0312\Eng1neering\Deg\E0312F02.deg 05/12/2005 03,3444 PH PD
Technical Information Report for Ridgeview Court May 12, 2005
' SECTION 2 CONDITIONS & REQUIREMENTS SUMMARY
The 1998 King County Surface Water Design Manual Core and Special Requirements and
Hearing Examiner's Conditions are being met in the following manner:
' King County Surface Water Design Manual Core Requirements:
' 1. Discharge at the Natural Location
Runoff produced by the developed site will discharge at its natural location.
2. Off-site Analysis
See Section 3 of this TIR.
t3. Flow Control
' Calculations provided in Section 4 of this TIR conform to the requirements set forth in
the 1998 KCSWDM per City of Renton requirements.
4. Conveyance System
All conveyance systems proposed conform to the 1998 KCSWDM per City of Renton
requirements, see Section 5 of this TIR for additional information.
' 5. Temporary Erosion & Sediment Control
All TESC measures proposed conform to the 1998 KCSWDM per City of Renton
requirements, see Section 9 of this TIR for additional information.
' 6. Maintenance & Operations
A maintenance and operations manual will be provided after first review of the
construction/ final engineering drawings. Refer to Section 10 of this TIR for more
information.
' 7. Financial Guarantees & Liability
A bond quantity worksheet will be provided after first review of the construction/ final
engineering drawings. The project owner will provide bonding as necessary.
8. Water Quality
' Water quality calculations provided in Section 4 of this TIR conform to the 1998
KCSWDM per City of Renton requirements, see Section 4 of this TIR for additional
information.
1
American Engineering Corporation Page 4
Technical Information Report for Ridgeview Court Mav 12, 2005
1 King County Surface Water Design Manual Special Requirements:
1. Other Adopted Area-Specific Requirements
There are no area-specific requirements for this project site.
1 2. Floodplain/Floodwav Delineation
There are no King County classified streams or wetlands on-site (per the 1990 KC
Sensitive Area Map Folio).
3. Flood Protection Facilities
There are no flood protection facilities located on or directly adjacent to the site.
4. Source Control
' This site does not meet the threshold for source control requirements.
5. Oil Control
This site does not meet the threshold for oil control requirements.
i
1
1
1
American Engineering Corporation Page 5
i
' Technical Information Report for Ridgeview Court May 12, 2005
1 Hearing Examiner's Conditions:
This section will be updated once the conditions of approval are obtained.
American Engineering Corporation Page 6
Technical Information Report for Ridgeview Court May 12, 2005
SECTION 3 OFF-SITE ANALYSIS
rTASK 1 —STUDY AREA DEFINITIONS AND MAPS
1
Overview
This section of the TIR is a Level 1 Downstream Analysis per the King County Surface Water
Design Manual Section 1.2.2.1 and 2.3.1.1 as required by the City of Renton.
The proposed project (Ridgeview Court) is the subdivision of 2.5 acres into 20 new single family
residences. The site is located in the City of Renton at 327 Bremerton Avenue NE (KC Parcel
No. 5182100042), see Figure 1: Vicinity Map. More generally, the site is located within the
Northwest Quarter of Section 15 of Township 23 North, Range 5 East, W.M. Topography of the
site area generally slopes from northeast to southwest, see Figure 3: Existing Conditions Map.
There is one point of surface water outfall from the site. Therefore, the site consists of a single
basin. Please refer to Task 4 for more detailed information regarding runoff downstream of the
site.
r
' Upstream Drainage Analysis / Upstream Contributing Area
Per the surveyed topography there are approximately 0.26 acres of upstream area tributary to the
' site. The field investigation also confirmed the upstream contributing area, see Figure 4:
Upstream Contributing Area Map.
1
1
1
r
i
i
American Engineering Corporation Page 7
1
m
0
1
I
CLUSTER r
z 4 CLUSTER
EX rWr 1 ca i ORANGERIM
a
12' E PAINT DUSTING GARAGE I I GRAPHIC SCALE
12"L E-l06'.07 `, ,y� / _ I IY I 15 0 15 30 60
fir. $r •• / \ +. I
)ELE BOX(rrPf li � �''MM_ / � � i I I � t INCH=90 F[.
11
Hl
PP W/UC P, \ °•1�i_
APPROX. WA TER Ow •I PY(IYPI. a L' TYP R L04 \ \ pP. ry pp//S/W ..
V PP/ 0.
LOCH ROV �� I APPDX_,WATER
BREMERTON AVE. N. E. CURB CD
CURB l•ERr FACE NUIL80% \UGP PAINT ASPHALT ROAD SURFACE WATER P INTO -_ —
11-51
YELLOw STR/PE 7 ASPHALT PArL7l - 136TH AVE. S. E.
.,.a• .. �� ` _ _ N00'44'31-E \ 330.03' 1D MPH s/GN
`�� , - 4-� I, =40L- \ `: - / LOGATXTWIWATFR - o Z
402
PROPOSED DEV 90V 0 0
Ex 7rPE 1 CB - �' ♦ 1 / \ _ �� _108— x N w cD O£AD ENO SIGN RG/EZ-408. C 1 tt* ..r /i
t£ROCAL CURB FACE 1?"CUP E-,ID6.16 1 ,t \„gyp 5j , ` �� .. I!f Q Z C W
1 4JC✓.E4 - '�iT T
o` c` i1
1 i i y
x 1 I 9 A� V � �� /�� � } >
104
1 GRAVEL DRIVE
xl ��;: �\�; 1` SoNculsMRr , �\� � PASTURE' ,� � I�
II Xb
MODELED AS LAWN I 11 `'; w 1.21 �4C I I ( 3
c t t,gyp ` i$
0.07 AC j n
u a
406.3 J� \5� � ` / / / \ \� ` o
z
^ _ m w o Lt i
x �� I t'o
` < a
"
410
1-410
40,
`� , 1 11 �• 11 j ' o
\°°� l jI j1� mop
0 -
C C o
•` Q ivy �) I j j j��i it aWU €
x , I � !
,� FOREST .,
Qx 0.94/AC
Z I
---------------------------------- I f' ! `°�s TOTAL AREA= ONSITE + OFFSITE
m e xQ.
3b1$
IMPERVIOUS:
ONSITE=0.08 AC
*L OFFSITE=0.06 AC
xI TOTAL=0.14 AC
E-1
06 — - _ PERVIOUS: _ Z
4�' .404, �730.32' NOO-47.45-E r` ONSITE PASTURE=1.21 AC O
4 ONSITE FOREST=0.94 AC
1 Ex RUDED CUR o �I N
► I �V �0 Ao■ ONSITE LAWN=0.17 AC 1—+
NOT GAPPED 9 P-ONE ���0 OFFSITE FOREST=0.20 AC Ga
OHO I 0.70 W OF s s
v I OFFSITE PASTURE=0.25 AC Zo
' I
� I TOTAL=2.77 AC W
JOB NoW
0312
SHEET
FIG 3
0
CLUSTER •.,�, --�-� o
ff ,-CLUSTER
( l! ORANGE f
PAINTG f I I I \ GRAPHIC SCALE
8.0
t ace-ao n.
— TtZE Bar(rm) FIRE Mro s
PP wNc PAR w a /- t I m '0 1 i `?
qfP
APPROX. WATER N/$/W
LOCA ROM A• /1
ERTON AVE. N. E. cuRa cur 6
— 7 _ cuRe WRr FACE r
YELLOW VRLPE A
136TH AVE. S. E.
/ SPMAL r PA...
:.. .'.t• f.&OEWALK ••...- ,�', '.:..I •.� _ 00 '31'E 330.03'402 - • / APPox WA7FR TO MPH SIGN/
\ N * \ \ COCA. o p
CONC PAD PROPOSED OEV SiCN AV _ 'ARE
I
o-
I m a
0OFFSITE BREMERTO
b£RCAL L/RB FALL IMPERVIOUS=0.06 AC-
32-PASTURE=0.25 AC
TOTAL=0.31 AC VI
w
II
a
UPSTREAM
CONTRIBUTING
AREA (TYP)
g
I I OFFSITE -$�
FOREST AREA
I I 0.20 AC,,., \ \ I \ \
Z zfr to
\ 406 o p
\ � ` I
2
0m � W
mrn°' 9<Wu
€
T6 •`, I I I I I I I III,I IIONb33:-
Lr
IIIII�I II
=JI
I =y
6N;f�ts E�yy
_ z
E, E-I
400.E _ = Z — ,+o+,, f 30.32 N00'4T45'E /` N 1�
400—39g — > \ \ \ \ \\\`\\\\ E
pp' ExrnuoEo CURB �
REBAR MOT CAPPED
0.to'W OF P-LE
A. `I.P6,
TM
I I
I I �
a
Ica No
0312
;IEET
FIG 4
Technical Information Report for Ridgeview Court May 12, 2005
TASK 2 —RESOURCE REVIEW
Adopted Basin Plan
The site is located in the Lower Cedar River Sub-basin and Cedar River Basin (see King County
Drainage Basin Map in Appendix "A").
Community Plan
The site is located in the Newcastle Community Planning Area (see Community Planning Area
Map in Appendix "A").
Basin Reconnaissance Summary Report
A basin reconnaissance summary report could not be obtained for the Lower Cedar River Sub-
basin.
Critical Drainage Area
' The site is not located in a Critical Drainage Area as defined by the 1998 KCSWDM.
' Sensitive Area Map Folio (FEM A Maps)
' The King County Sensitive Area Maps from the internet did not show that the site contained any
wetlands, 100-year floodplains or seismic hazard areas, coal mine hazard areas, erosion hazard,
landslide hazard, and landslide hazard drainage area. Therefore, no mapped sensitive areas are
on or adjacent to the site.
The City of Renton maps show a small stream meandering down the center of the site. However,
field reconnaissance did not show any streams, channels, standing water or flowing water at the
time of the site visit. Therefore, no streams are present on the site. Furthermore the wetlands
report by Alder NW dated March 13, 2003, concluded that no wetlands or streams are present on
or adjacent to the site.
American Engineering Corporation Page 10
Technical Information Report for Ridgeview Court May 12, 2005
SCS Soils Survey
The SCS Soils Map of King County shows the soil on-site to be Alderwood Gravelly Sandy
Loam (AgC), see Figure 4: SCS Soils Map. This soil type is classified as till per Table 3.2.2.B
in the 1998 KCSWDM, see Appendix A for Table 3.2.2.B. The Soils report by Geogroup
Northwest dated October 4, 2004 generally agrees with the above mentioned soils description,
see Appendix C for more information.
' Wetland Inventory
There are no wetlands on or near the site. This is also confirmed by the wetland analysis by
Alder NW dated March 13, 2003, see copy of Wetland Study in Appendix B for more
information.
Drainage Complaints
Cindy Torkelson at WLR Stormwater Services Section was contacted regarding drainage
complaints within the downstream area. These findings are described in further detail below.
WLR Stormwater Services Section found several complaints within the area. However, none of
these complaints were located on or near the downstream flow path from the proposed discharge
of the site. Therefore, the developed runoff from this project should not create adverse
downstream effects. Please refer to Appendix A for the complaint list.
American Engineering Corporation Page 11
V
An
\,���.1 a � • Viler '�,;,�' '+•'-;,71. It.�V6 . ,� '� �•�•• ti's
• `:i 1� �/■ ■ .� ark, ii w: 7
_ 11 .8 'ngM . . =.
42,r .� Apr• I
1 Greenwood Ge1
EvC
O I, icy F:
n �4. ik� c , �"rw .: _J <rF -..�r� �
A �
eh 1YGRAVEL 'PIT
321:am
11144 it
' ,iY. I l _ -_ •' \\ „ S+.N „ w r •PSG• - A y
tRkE�• `,s �' �I � `�< �,, ( .;.� -ems ^
@
.
` ...;a4..' • .w.. �
(Jr \• `••''� !• .� J;�w4�',r..� ,E,.s, - .�Y�,t r ���:77,. •I I Sz'k t' g'O-J�L,„�,...s
•"i. '... �; •0' '� g4'I' �H ^. Ash �'..W,-_
- ,. S>.• ... '. '•`�•• .mot" b� '��;' ,.�r�,`ui._.
`"f �h� P.�, na#'.AS::'�Y'!3 •.-_ ��'� -,,-�•.1" r�5 .:""'�. �-''�.'i"a t r'•i¢��� n. y;
' ebr BMj37 Ak1 :: `PYd G - jNaj r .. r
Asa !& °, + 4 •; r� .�. � ,
'I' e;6���-� � •t \\\ B � � ��\r ` E QG•''('• '�. i t\_ ' � 1 s �. .;r d�"'r�{ ,r �`�,7 �
Ic
aA• .L,i�• a�/- �p e, pNg I }• �•
a SOIL LEGEND , u E o
•u
JI
Ur
a NB •
The first cooirol :etrer s•he init a one of the soil name. A second capital letter, Park
' }r
are
3, C E ar vel s res the cl "r' r sA
� � ass of slope. Symbols without a slope letter •.?rE � ,�
are those of necr;y level saQc. . S. *<� � ,
.._... SYMBOL NAME
t76 Aga Alderwood gravelly sandy loam,0 to 6 percent slopes AgC giderwood grovelly sandy loam,6 to 15 percent slopes _ _a___, _•:
Agc Alderwood gravelly sandy loam, 15 to 30 percent slopes A 6 e
' AkF Alderwood and Kitsao soils,very steep ( H
AmB Arenrs, Alderwood material,0 to 6 percent slopes
AmC Arenrs,Alderwood material,6 to 15 percent slopes• � } "
An Arenrs, Everett material•
AW
SeC 9eausire gravelly sandy loam,6 to 15 percent slopes r n I s
BeD Beeusire gravelly sendy loam, 15 to 30 percent slopes
e 6h Bellingham silt loam J' - _•.. �. r _ E1M I ;Ag9
' Br -Brisc or silt loam 27 i - •..
'A98 Su Buckley silt loamh492 I `
45 11
.`3 .va..'w N - •-Fj.� .71 rr .V�� .I
American Engineers • Planners • Surveyors RIDGEVIEW COURT
' Engineering 4032 148th Ave. N.E
Corporation Redmond, WA 98052 C S C C J S 0 I SOILS M A P
PHONE(425) 881-7430 Fa. (425) 881-7731 PROJECT NUMBER DATE- ••JJ SCALE FiGUR:
' P.\2003\0312\Engineering\Dwg\E0312rG5.d.g 07/20/2004 1123.06 AM PDT 0312 0/—20-04 AS NOTED 5
' Technical Information Report for Ridgeview Court May 12, 2005
TASK 3 — FIELD INSPECTION
' A site visit was made on July 8, 2004, during a partly sunny day with temperatures around 65
degrees. There had not been much rain in the previous few days.
The site is currently undeveloped and consists primarily of sparse forest on the northern portion
of the site and pasture type of vegetation on the southern portion of the site. The site can be
accessed from 136`h Avenue SE. The topography of the site generally slopes in the southwesterly
' direction into a low point. There were no visible drainage problems or recent unstable ground
activities observed on-site at the time of the field investigation.
TASK 4—DOWNSTREAM ANALYSIS DESCRIPTION
Drainage System Description
Runoff from the site sheet flows southwesterly into the low point of the site(Point A). Runoff
continues in the westerly direction in a very broad ditch (Point B) until entering a wetland (Point
' Q. Runoff leaves the wetland in the southwest direction and enters into a drainage channel
(Point D). The drainage channel originates in a larger wetland westerly of Point C. This larger
wetland is denoted as Point E on the map and is located near the intersection of the Union
' Avenue NE and NE 4th Street. However, once runoff from the site leaves the wetland
downstream of the project (Point C) and enters in the drainage channel (Point D), runoff flows in
the southerly direction. Runoff continues flowing southerly in this drainage channel (Point D)
until reaching a culvert (Point F). Runoff is directed into a 60-inch diameter structure (Point G)
and then under Bremerton Place NE to the east via a CMP culvert (Point H). This is where the
downstream analysis was terminated. However, runoff discharges on the southeast side of
Bremerton Place NE (Point I), entering Maplewood Creek (Point J), and appeared to continue
flowing in the southerly direction.
' Please reference Figure 6: Downstream Flow Map and Figure 7: Downstream System Table
more details on the downstream field investigation.
No downstream problems were observed at the time of the field investigation.
American Engineering Corporation Page 13
1
�w � w ww w ww w wi ww w w w �w ww w w w� w w
------ cIY Iy ,.. rFl•'6,L_ � ( V
h4 V5
o t vE oS�d uObYy �
o 6 6 +-
6 � t
Rl .8S LS . o a6f� 8f [l 9£ _ SI 41 ff z
ti r
~
"301 C9/
,u os o o °cl St 2y0 % kzi silk _ k y
P
yr OV'Gf9 � cr+ fl- •.�� �, t
-- N
` ���
-- 6(4fl 1� ' �'� '.II 6'y�Y- �• y'c � (' - + 1t SY 1'�
l It! 6
Val .3 ZI ' �: fl 41 SI " 91 LI 81 61 OC EI IL lZ CZ
�-- - [U OE9 a e1001 -• G09- p•Y09 4f11 I-SIIV S01 I( 201 4 !U ,y IIG fI-bE\ 111
r 4
---- -- (� - SZ o IZ OZ a� EI 81 �. 1I1:� ( 01
- Dk�--- of yZ -<v al 4RfS Y b tx ' ..
f4Z£I�
iL JV (LJ d� g�• � � �' , �/ �15fY �9. ,,�.., y ,'lF,.• W y �,.p�Y
w IZ p 'J }" 6F•`\ £z -Sly,e4 6
4 n 2Sil��a - - 2 0 n`.
OUIi t616
SEd!
6oi f z 1 _ o LZ 2 on o/, s
s__0� 19 c bps ?o
tf�/� U a 4 7i9 i - rt mite J)� ti
tlyit tr n~ 6i B[► >
m OVZ �1 (I Wct pU+ c0 WyZt 91 .� SI p1 tr f
A SZ.Z 01[ 8Z rn 04 , ��` s►iE ezq >ti fd t° N
5n M, 9 9t
v1D'J` J 9.0 n° - d(--- v !D I
" IV - 4 S9Z ty�� tilt s\4N r+ £9 b9 6
-- — c 11"CZ9 -- —.. 11 Z �. s 8 q�''�cs S v�. x
n --61T- c9
8£ 'YA 1 1 t -
1 ¢ v ,•i E9 -02
N 3 \ N -S6 �yl 29
` 4 tr d X. 19
-Is
(�1 'JH 9I '17 'LVl aAiy o iGt�
\\
\ oil -j20P
0S .1�s
r0\
''SI
Iv I l£ ££ K S 1 L4 " 81, 60 �s�9S LS IRSr`'� 6S1
_ 0--- li —- !_ E US I f l0 2 Y F' .0 I. 60.
NA NI a's sl S.a 01 1S ONZ
I I' !F 41121 E045 09 '
1.Iw.w -
1 W La 6H -08 YLV Ad US !
1 P K01
1w . VI ►B F� It V
/ �• I, L, n
l�.., - -. ------- -- --- --
�ZQ_...----: of � T7i - ---'il'02f`•'--- -- .- 19Z
U9
W
Y-E W P 1T
OS Ll u of o -----.—Y2t-- ---- - -
--'---•-------
T£I 0 18 N n -
h1
0918L9 dSAt
J (�
uY izu cof I czc 2f-(fd 2 e• _^F t z041V ---
1IWII cl210�st NO l r• A - --- cl
z> 4 A► oa l r
S . N118 \ W -
G
W w
a � 1
YL9'£Of I U .
1= 0C _
^'- IIiSOf 125fZf tv5t.\\�� /r_ u. W,„i -171
IWO
4G T OS �001 FOdEI . . f9212 09 C1 (£I
Z/OLf JU- -° mz o .n rn j � 690 6L01 d'S
- a sE !r '• . -
l
Ito-o uIz
Z ^ �
6 S ZO
o �jyCti
J )
7 Z
J' 4Z1 if I (i07110UZI
! OJ (( ❑ u v(9
! Yy l r
r f�1Z w 11
fin
/1r �)�i r3;nan•' I 1- - - I - I , 09
►" t\,:i
I$' 11 1ZCEL (i9 OF 122E2C •'Ltf —_.-_1Lj_'[t-k t1
_ 4�
8� -/..0 i..-1�*-.:-�•T-t ri-�3 _ -. .�. _ •I ...___.-•-er u• -_—.- _-'____- �:-_ __ �_-__ .rr._..'�•�
,A i.t6 IvN t.•I..49.ul--I -r`.-..11.p(. d... -- o l WPIZ
of
!st ool I' I • ' N�
V 2 c
1� _ t Q
pp 1 1 cn W
r, J �' m d\ I to � 1 1 I w t• �`I � 'V' 90'SW.� II �I
� V
----oci - - :)V SL'0 v
LI Z 01 L' 1'1 L; i ;xl 1 , z'FrI Inc•. __
' I
11 —z�C�II
-- �( Nit!� .d 3 1 1 Sj': J N 10 N 18 V
�d SZ r� 1 __ -._l I .hl
lIl
n �� 98 ,'�1 /'\1tYl V4Y ,i - ,I .�,.r.. ur: 1lt-'1
b RIDGEVIEW COURT Dale 07_2°-°4 No. Dote By
Rev1aOe,
y.e.I F GUN F
J n F 0, WASHis� American Engineers • Planners • Surveyors Scale AS SHOWN
o a DOWNS I'REAM FLOW MAP "I Engineering 4032148th Ave.N.E.
1. Corporation Redmond,WA 98052 D Dr.- NEB
Y� PO R 14013 O Designed
/l1 fSy.�C15TERE�G� PHONE(425)881-7430 Fox(425)881-7731 RWS
V� ONAL
File Poth R Name Checked
EM ES O4-05-2006 P-\2003\0312\Enpineerinq\D,g\E0312FG6.deq 07/20/2004 11!24-45 AM P01 E`'
r r r r r r r r lr r r r r r r r r r r
DOWNSTREAM ANALYSIS DRAINAGE SYSTEM TABLE
RIDGEVIEW COURT — CITY OF RENTON
Basin: Cedar River Subbasin Name: Lower Cedar River Subbasin Number: n/a
Symbol Drainage Drainage Slope Distance Existing Potential Observations of field
Component Type, Component from site Problems Problems inspector, resource
Name, and Size Description discharge reviewer, or resident
see map Type:sheet flow,swale, drainage basin,vegetation, % '/.ml= 1,320 ft. constrictions,under capacity,ponding, tributary area,likelihood of problem,
stream,channel,pipe, cover,depth,type of overtopping,flooding,habitat or organism overflow pathways,potential impacts
pond;Size:diameter, sensitive area,volume destruction,scouring,bank sloughing,
surface area sedimentation,incision,other erosion
A Discharge Point Runoff from site 2-25 0 none none No erosion problems
from Site
B Drainage Channel 4-6 ft Wide at top, +/- 2% 0-250 none none No erosion problems
2.5 ft Deep, 2:1 SS
C Wetland +/- 100 ft x 100 ft n/a 250-350 none none No erosion problems
D Drainage Channel 4-6 ft Wide at top, +/- 2% 350 - 1650 none none No erosion problems
2.5 ft Deep, 2:1 SS
E Wetland (not in 5 —6 Feet Wide, 4 n/a n/a none none No erosion problems
flow path) Feet Deep, 1:1 SS
F Culvert 12" Diameter(pipe +/- 2% 1650 - 1675 none none No erosion problems
type was not noted)
G Structure 60-Inch Diameter n/a 1675 none none No erosion problems
(2 - 12"pipes in
from channel)
H Culvert 36-Inch CMP +/- 2% 1675 - 1750 none none No erosion problems
I Outfall 36-Inch CMP n/a 1750 none none No erosion problems
J Creek (Maplewood) 24" diameter cone. ??? +1750 none none No erosion problems
Figure 7: Downstream System Table
Technical Information Report for Ridgeview Court May 12 2005
r SECTION 4 FLOW CONTROL & WATER QUALITY
ANALYSIS AND DESIGN
The calculations are based on the 1998 Kin Count Surface Water Design Manual K
g Y � ( CSWDM)
requirements, as adopted by the City of Renton. The site is located in the Cedar River Basin,
which requires a minimum of a Level 2 Flow Control analysis. Water quality features for the site
will be designed from the basic water quality menu.
' ExistingSite Hydrology
Y gY
' The site slopes to the southwest ranging from 2% to 25%, and becomes steeper along the
southern portion of the site. Vegetation on the site consists of sparse trees and underbrush in the
' northern portion of the site and shrubs and grasses in the southern portion of,the site, see Figure
3: Existing Conditions Map.
' The soil on the site is AgC, Alderwood Gravelly Sandy Loam and is classified as till soils by
Table 3.2.2.B in the 1998 KCSWDM, see Figure 5: SCS Soils Map.
' Developed Site Hydrology p y rology
' The proposed development will consist of 20 single family lots, an access tract with associated
roads and utilities, and also a separate storm drainage tract for the detention facility. The Public
Access Tract (Road A) will provide access to all of the lots from Bremerton Avenue NE. Runoff
from the roadways and lots will be conveyed to the detention vault located on the southwesterly
corner of the site. The detention vault will also include dead storage, which will provide water
' quality treatment for the project, see Figure 8: Developed Conditions Map.
' A runoff time series was created using the reduced 8-year data. The hourly series was used to
size the detention facility. The site is located within the Sea-Tac Region and has a scale factor of
1.0, refer to the Rainfall Regions and Scale Factor Map in Appendix D. The soils on site are
' Alderwood, therefore, a soil cover type of till was used.
American Engineering Corporation Page 16
m
I
CLUSTER`,` - a
lCLU'TER
a
ORANGE
PAINT
/ .._.,.._.,.,......,.� ( I 1� GRAPHIC Son 15 0 15 30
60
I rHce-ao n.
R Ago�o�--•—q0g-��uo ��)�L I` /
BREMERTON AVE. N. E. 12 13 /
-r UCP PAINT —LWP
scow srnrPE� � P " a' 138TH AVE. S. E. _
. .'.I VDEWALK \ - N00 f3jr 330.03 —
402 ! I I h
1
I I
I m
W
17 5
4 I s $ eo
-- I -- - - ' 4 406 W • a
I
- ------ C r R
5 14 ' t ' J I II� mc °a
1 7
fi
f I ?to" 33��°yam,
8 I
co
z x y I I I I I I 1 1 1
'I I! TOTAL AREA= ONSITE + OFFSITE W
a ey
i � bH31 Y15 EGA -
J II = 2.91 AC 3 pg0
x I I I I I I 9,D
-- --- I E �I T TR
IMPERVIOUS:
ONSITE ROADS/STRUCTURES=1.54 AC
OFFSITE ROADS (BREMERTON)=0.21 AC
emc. i 55 I a
ser TOTAL=1.75 AC a
•--:_ — - ;
- - = — _ �a0a., ! 30.32
00 N004T45*E .4 _ ._.-. __. \j
' EXTRUDEOCURB $ j \w \\\`\�\\ „ PERVIOUS: O Q
o ONSITE LAWN=0.86 AC p,
I I -u �9a J� \�,`• ' OFFSITE PASTURE=0.10 AC O Z
aio REw orVAR Ao LINE � • I OFFISTE FOREST=0.20 AC W W O
Ii TOTAL=1.16 AC W E
JOB NO.
0312
SHEET
FIG 8
Technical Information Report for Ridgeview Court Mav 12, 2005
Facility Design Methodology
The detention facility was sized by trial and error in accordance with the KCRTS detailed routing
' method, see Tables and KCRTS flow outputs below. The design intent for the detention facility
is to match the predeveloped peak durations for the 2-year, 10-year, and 50-year return periods to
half of the developed 2-year, 10-year, and 50-year respectively(Level 2 Flow Control Standard).
Existing Conditions: Total Area to be detained = 2.91 Acres
Offsite Area (Bremerton) = 0.31 Acres
Offsite Area(Contributing) = 0.20 ac
On-site Area=2.40 Acres
Impervious Surface:
On-site Impervious (structures) = 0.08 acres
Off-site Impervious (frontage) = 0.06 acres
Total Impervious = 0.14 acres
Pervious Surface:
On-site Till Grass = 0.17 acres
' On-site Till Pasture = 1.21 acres
On-site Till Forest = 0.94 acres
Off-site Pasture (Bremerton) = 0.25 acres
Off-site Forest (Contributing) = 0.20 acres
Total Pervious = 2.77 acres
Predeveloped KCRTS Output
Flow Frequency Analysis
Time Series File:predev.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) Period
0.211 2 2/09/01 15 :00 0.360 1 100.00 0.990
0.094 7 1/05/02 16:00 0 .211 2 25.00 0 .960
0 .200 3 2/28/03 3 :00 0 .200 3 10.00 0 .900
1 0.044 8 8/26/04 2 :00 0 .190 4 5.00 0.800
0.115 6 1/05/05 8 :00 0 .177 5 3 . 00 0 .667
0. 190 4 1/18/06 16:00 0 .115 6 2 .00 0.500
0.177 5 11/24/06 4 : 00 0.094 7 1.30 0 .231
i 0.360 1 1/09/08 6:00 0 .044 8 1.10 0.091
Computed Peaks 0.310 50.00 0.980
American Engineering Corporation page 18
Technical Information Report for Ridgeview Court May 12, 2005
Developed Conditions: Total Area to be detained = 2.91 Acres
Offsite Area (Bremerton) = 0.31 Acres
Offsite Area (Contributing) = 020 ac
' On-site Area= 2.40 Acres
Impervious Surface: ) �o✓vlvf)>
On-site Roads/Structures/Driveway = 1.54 acres
Off-site Roads = 0.21 acres
Total Impervious = 1.75 acres
Pervious Surface:
On-site Till Grass = 0.86 acres
Off-site Pasture = 0.10 acres
Offsite Forest (Contributing) = 0.20 acres
Total Pervious = 1.16 acres
Developed Area Output for site
Flow Frequency Analysis
Time Series File:dev.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
1 (CFS) (CFS) Period
0.515 6 2/09/01 2 :00 1.04 1 100.00 0.990
0.419 8 1/05/02 16:00 0 .658 2 25.00 0.960
0.616 3 2/27/03 7 :00 0.616 3 10. 00 0 .900
0.452 7 8/26/04 2 :00 0.547 4 5.00 0.800
0.544 5 10/28/04 16 :00 0.544 5 3 .00 0.667
0.547 4 1118106 16 :00 0.515 6 2 .00 0.500
0 .658 2 10/26/06 0 :00 0.452 7 1.30 0 .231
1.04 1 1/09/08 6:00 0.419 8 1.10 0 .091
Computed Peaks 0.910 50.00 0.980
Retention/Detention Facility
Type of Facility: Detention Vault
Facility Length: 110.00 ft
Facility Width: 48 .00 ft
Facility Area: 5280 . sq. ft
Effective Storage Depth: 6.25 ft
1 Stage 0 Elevation: 396.00 ft
Storage Volume: 33000. cu. ft
Riser Head: 6.25 ft
Riser Diameter: 12 .00 inches
Number of orifices : 2
Full Head Pipe
Orifice # Height Diameter Discharge Diameter
(ft) (in) (CFS) (in)
1 0.00 1. 10 0.082
2 2 .75 1.10 ✓ 0.061 4 .0
Top Notch Weir: None
Outflow Rating Curve: None
1 American Engineering Corporation Page 19
1 Technical Information Report for Ridgeview Court May 12, 2005
Stage Elevation Storage Discharge Percolation
(ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs)
0.00 396.00 0. 0 .000 0.000 0 .00
0.01 396. 01 53 . 0.001 0 .004 0 . 00
0.02 396.02 106. 0.002 0 . 005 0 . 00
0.03 396.03 158 . 0.004 0. 006 0 . 00
0 .05 396.05 264 . 0.006 0 .007 0 . 00
0.06 396. 06 317. 0.007 0.008 0 . 00
0.07 396. 07 370 . 0.008 0 .009 0 .00
0.08 396. 08 422 . 0.010 0 . 009 0 . 00
0.09 396. 09 475 . 0 .011 0 . 010 0 . 00
1 0.20 396.20 1056. 0.024 0 .015 0 . 00
0.30 396.30 1584. 0 .036 0 . 018 0 . 00
0.41 396.41 2165. 0.050 0 . 021 0 .00
0.52 396.52 2746. 0 .063 0 . 024 0 .00
0.62 396.62 3274. 0 .075 0 . 026 0.00
0 .73 396.73 3854 . 0.088 0 .028 0 .00
0. 83 396. 83 4382 . 0.101 0 .030 0 .00
0.94 396.94 4963 . 0.114 0 .032 0 .00 ,
1.05 397.05 5544 . 0.127 0 .034 0 .00
1. 15 397. 15 6072 . 0.139 0.035 0 . 00
1.26 397.26 6653 . 0.153 0 .037 0 .00
1.36 397 .36 7181. 0.165 0.038 0.00
1.47 397 .47 7762 . 0.178 0.040 0 .00
1.57 397 .57 8290. 0.190 0.041 0 .00
1.68 397.68 8870. 0.204 0.043 0.00
1.79 397.79 9451. 0.217 0 .044 0 .00
1. 89 397.89 9979. 0.229 0 . 045 0.00
2 .00 398 .00 10560. 0 .242 0 .046 0.00
2 . 10 398 .10 11088. 0.255 0 .048 0.00
2 .21 398.21 11669. 0 .268 0 .049 0.00
2 .32 398 .32 12250. 0 .281 0 . 050 0 .00
2 .42 398 .42 12778. 0 .293 0 .051 0.00
2 .53 398 .53 13358. 0 .307 0 .052 0.00
2 .63 398 .63 13886. 0 .319 0 . 053 0.00
2 .74 398 .74 14467. 0 .332 0 . 054 0.00
2 .75 398 .75 14520. 0.333 0 . 054 0.00
2 .76 398 .76 14573 . 0.335 0 .055 0.00
2 .77 398 .77 14626. 0.336 0 . 056 0.00
2 .78 398 .78 14678 . 0.337 0 . 057 0 .00
2 .80 398 . 80 14784. 0.339 0 . 059 0.00
2 .81 398 .81 14837. 0.341 0 . 061 0.00
2 .82 398. 82 14890. 0.342 0 . 064 0 .00
2 .63 398. 83 14942 . 0.343 0. 065 0.00
2 .84 398. 84 14995. 0.344 0 . 065 0.00
2 .95 398.95 15576. 0.358 0 .071 0.00
3 .05 399.05 16104. 0.370 0 .075 0 .00
3 .16 399. 16 16685. 0.383 0 .079 0 .00
3 .27 399.27 17266. 0.396 0 . 083 0 .00
3 .37 399.37 17794 . 0.408 0 .086 0 .00
3 .48 399.48 18374 . 0.422 0 .089 0 .00
3 .58 399.58 18902 . 0 .434 0.092 0 . 00
3 .69 399.69 19483 . 0.447 0.095 0 . 00
3 .80 399.80 20064. 0 .461 0 .097 0 .00
3 .90 399.90 20592 . 0.473 0.100 0.00
4 .01 400.01 21173 . 0.486 0 .102 0.00
4 .11 400.11 21701. 0.498 0.105 0 .00
4 .22 400 .22 22282 . 0.512 0 .107 0 . 00
4 .32 400.32 22810. 0 .524 0 . 109 0 .00
American Engineering Corporation Page 20
Technical Information Report for Ridgeview Court May 12, 2005
1 4.43 400 .43 23390. 0 .537 0 . 112 0 .00
4.54 400 .54 23971. 0.550 0 .114 0 .00
4 .64 400.64 24499. 0 .562 0. 116 0 .00
4 .75 400 .75 25080 . 0.576 0. 118 0.00
4 .85 400.85 25608 . 0 .588 0.120 0 .00
4 .96 400. 96 26189. 0.601 0.122 0 .00
5 .07 401.07 26770 . 0.615 0.124 0.00
5 .17 401.17 27298 . 0.627 0 . 126 0.00
5 .28 401.28 27878 . 0.640 0 . 128 0 .00
5 .38 401.38 28406. 0.652 0.129 0 .00
5 .49 401.49 28987. 0.665 0 .131 0 . 00
1 5 .60 401.60 29568 . 0.679 0 .133 0 .00
5 .70 401.70 30096. 0.691 0.135 0 . 00
5 .81 401. 81 30677. 0.704 0.136 0 .00
5 . 91 401. 91 31205 . 0.716 0.138 0.00
' 6.02 402 .02 31786. 0.730 0 .140 0 .00
6. 13 402 . 13 32366. 0.743 0 .142 0.00
6.23 402 .23 32894. 0.755 0 .143 0.00
6.25 402 .25 33000 . 0.758 0 .143 0.00
6.35 402 .35 33528 . 0.770 0 .453 0.00
6.45 402 .45 34056. 0.782 1.020 0.00
6.55 402 .55 34584 . 0.794 1.750 0. 00
6.65 402 . 65 35112 . 0 .806 2 .540 0 . 00
6.75 402 . 75 35640. 0 .818 2 .830 0 .00
Hyd Inflow Outflow Peak Storage
Target Calc Stage Elev (Cu-Ft) (Ac-Ft)
1 1.04 0 .35 0 .14 6.18 402 .18 32645. 0.749
2 0.66 ******* 0 .07 2 .92 398.92 15432 . 0.354
3 0.62 ******* 0.10 4.05 400.05 21374 . 0.491
4 0.54 ******* 0.04 1.55 397.55 8196. 0.188
5 0.55 ******* 0.10 4.03 400.03 21289. 0.489
6 0.51 ******* 0. 13 5.56 401.56 29383 . 0.675
7 0.45 ******* 0 .05 1.90 397. 90 10045 . 0.231
8 0 .42 ******* 0 . 05 2 .41 398 .41 12728 . 0.292
----------------------------------
Route Time Series through Facility
Inflow Time Series File:dev.tsf
Outflow Time Series File:rdout
Inflow/Outflow Analysis
Peak Inflow Discharge: 1.04 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.143 CFS at 16:00 on Jan 9 in Year 8
Peak Reservoir Stage: 6. 18 Ft
Peak Reservoir Elev: 402 . 18 Ft
Peak Reservoir Storage: 32645 . Cu-Ft
0.749 Ac-Ft
American Engineering Corporation Page 21
' Technical Information Report for Ridgeview Court May 12, 2005
Flow Duration from Time Series File:rdout.tsf
' Cutoff Count Frequency CDF Exceedence_Probability
CFS $ $
0.002 36511 59.542 59.542 40 .458 0.405E+00
0.006 2657 4.333 63 .875 36. 125 0.361E+00
1 0.009 3745 6. 107 69.982 30. 018 0 .300E+00
0.013 3058 4 . 987 74 . 969 25 .031 0.250E+00
0.017 2867 4 .675 79.644 20.356 0 .204E+00
0 .020 2599 4 .238 83 . 883 16. 117 0 . 161E+00
0.024 2129 3 .472 87.355 12 .645 0.126E+00
0.028 2075 3 .384 90.739 9.261 0. 926E-01
0.031 1376 2 .244 92 .983 7.017 0. 702E-01
0.035 1165 1. 900 94 .883 5.117 0 .512E-01
1 0.039 766 1.249 96. 132 3 . 868 0.387E-01
0.043 575 0. 938 97.069 2 .931 0.293E-01
0.046 588 0.959 98.028 1.972 0. 197E-01
' 0.050 366 0.597 98 .625 1.375 0.137E-01
0.054 315 0.514 99.139 0.861 0. 861E-02
0.057 87 0.142 99.281 0.719 0. 719E-02
0.061 19 0.031 99.312 0.688 0 .688E-02
0.065 14 0.023 99.335 0 .665 0.665E-02
0.068 64 0.104 99.439 0.561 0.561E-02
0.072 49 0.080 99.519 0.481 0.481E-02
0.076 36 0.059 99.578 0.422 0 .422E-02
0.080 21 0.034 99.612 0.388 0 .388E-02
0.083 17 0.028 99.640 0.360 0.360E-02
0.087 22 0 .036 99.675 0.325 0.325E-02
0.091 17 0. 028 99.703 0.297 0.297E-02
0.094 21 0.034 99.737 0.263 0.263E-02
0.098 34 0.055 99.793 0.207 0 .207E-02
0.102 36 0.059 99. 852 0. 148 0.148E-02
0. 105 17 0 .028 99.879 0. 121 0 .121E-02
0.109 11 0. 018 99. 897 0.103 0. 103E-02
0.113 10 0.016 99.914 0.086 0. 864E-03
0.117 14 0.023 99.936 0.064 0.636E-03
1 0.120 5 0.008 99.945 0.055 0.554E-03
0.124 10 0.016 99.961 0.039 0.391E-03
0.128 11 0.018 99.979 0.021 0.212E-03
0.131 9 0.015 99.993 0.007 0 .652E-04
1 Duration Comparison Anaylsis
Base File: predev.tsf
New File: rdout.tsf
Cutoff Units : Discharge in CFS
-----Fraction of Time----- ---------Check of Tolerance-------
Cutoff Base New $Change Probability Base New $Change
0.058 I 0 .71E-02 0.71E-02 -0 .2 I 0 .71E-02 0. 058 0.058 -0.2
0 .070 0.53E-02 0.53E-02 -1.5 I 0.53E-02 0.070 0 .070 -0.4
0.082 I 0 .41E-02 0.37E-02 -10 .2 I 0 .41E-02 0 .082 0.077 -5 .9
0.093 I 0 .30E-02 0 .27E-02 -10.3 0.30E-02 0.093 0 .090 -3 . 8
0. 105 0 .23E-02 0.12E-02 -46.4 I 0.23E-02 0 . 105 0.097 -8 .0
0.117 0. 16E-02 0 .62E-03 -62 . 0 I 0.16E-02 0.117 0 . 101 -13 .7
0.129 I 0.12E-02 0.15E-03 -87.3 0 .12E-02 0 . 129 0.107 -17.3
0.141 0. 86E-03 0.00E+00 -100. 0 0.86E-03 0.141 0. 113 -19.6
0.152 I 0.62E-03 0.00E+00 -100.0 0 .62E-03 0 . 152 0.117 -23 .2
0.164 I 0 .46E-03 0.00E+00 -100 .0 0.46E-03 0.164 0. 122 -25.4
0 .176 0.23E-03 0. 00E+00 -100.0 0.23E-03 0. 176 0.127 -28.0
0.188 0.15E-03 0.00E+00 -100 .0 0. 15E-03 0.188 0 . 129 -31.2
0.199 0 .65E-04 0 . 00E+00 -100.0 0.65E-04 0. 199 0.132 -33 .9
American Engineering Corporation Page 22
Technical Information Report for Ridgeview Court May 12, 2005
Maximum positive excursion = 0 .004 cfs ( 7.0%)
occuring at 0 .060 cfs on the Base Data:predev.tsf
and at 0 .065 cfs on the New Data:rdout.tsf
Maximum negative excursion = 0 .078 cfs (-37. 0%)
occuring at 0 .210 cfs on the Base Data:predev.tsf
and at 0 .132 cfs on the New Data:rdout.tsf
See below for image rdout and target. Note that rdout is within the 10% allowance per the target.
Therefore, the release rate out of the detention vault is per requirements set forth in the 1998
KCSWDM per City of Renton Standards.
T-
N
W rdout.dur
target.dur
CD
L
} o R ,
�• CN
0
L o vi 4 f
o
00
o
o
10 -5 10 _4 10 -1111 3 10 -Z 10 -� 10°
Probability Exceedence
1
American Engineering Corporation Page 23
Technical Information Report for Ridgeview Court May 12, 2005
Wetpool Sizing:
tV,=[0.9A;+0.25Atg+0.25Ap+ .01Ao](R) Where:
�v 0
_ [0.9(7 30) + 0.25 7,462 + ��� Vr =Runoff Volume from Mean Annual Storm
1 0.25( ;356) (0.039) (cfl
✓ 4 A; =Area of Impervious Surface (sf)
= 3,083 cfy �°� A,o=Area of Till Grass (sf)
�c rn AP=Area of Till Pasture (sf)
5 H G j� Ao=Area of Outwash Soils (sf) (N/A)
Vb=fV,. Vb =Required Wetpool Volume (cf)
f =Volume Factor(3.0 for basic ponds)
= 3.0 (3,083) = 9,249 cubic feet R =Rainfall from Mean Annual Storm(ft)
required (from KCSWDM Figure 6.4.1.A)
=0.039
Total Volume Provided in the Wet-Vault= 15,840 CF ( 110' x 48' x 3' )
1 American Engineering Corporation Page 24
Technical Information Report for Ridgeview Court May 12, 2005
SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND
DESIGN
Detention Vault Outlet Riser
1 The outlet riser for the combined detention / wet - vault facility has been sized per Section 5.3.4
of the 1998 KCSWDM. A 12-inch diameter riser, with 0.50 feet of head can convey 2.67 CFS.
The 100-Year Developed peak flow is 1.02 CFS, therefore a 12-inch riser will be adequate.
I = 3.782 DZ H
QORIFICE ( )( )
1 Where D = diameter(ft) — 1.00'
H =head (ft)—0.50'
Qoa1F10E = 3.782(1.002)(0.501/2) =2.67 CFS
See Figure 5.3.411 Riser Inflow Curves in Appendix D.
On Site Conveyance Calculations
The flows on site were found by using the rational method for checking the backwater of the
conveyance system, an acceptable method per the 1998 KCSWDM. Once the flows were
obtained, the King County Back Water Program was used to run the backwater analysis and the
pipes were sized to ensure no overtopping would occur. The storm drainage conveyance system
1 was sized to ensure that during the 25-Year 24-Hour storm event the conveyance system is able
to convey the flows without overtopping occurring. Furthermore, the conveyance system was
also checked to ensure that during the 100-Year 24-Hour storm events the system would function
1 adequately and no overtopping would occur at any of the structures. It was found that the system
does indeed function per the requirements set forth in 1.2.4 of the 1998 KCSWDM standards.
Refer to Table VLA - HGL vs. Rim and also inputs and outputs in Appendix D.
i
1
American Engineering Corporation Page 25
Technical Information Report for Ridgeview Court May 12, 2005
Rim Elev vs. HGL Elev Table
Table VLA -HGL vs. Rim
1 System
No. CB NO. RIM ELEV. 100-YR HGL ELEV FREEBOARD (FT)
1 1 2 402.85 402.40 0.45
1 3 403.27 402.76 0.51
1 4 404.51 403.45 1.06
1 5 406.46 403.65 2.81
1 6 408.59 403.73 4.86
1 7 408.83 403.76 5.07
1 8 404.89 403.84 1.05
1 9 404.89 403.84 1.05
2 1 404.18 402.24 1.94
3 14 403.64 402.77 0.87
4 13 403.69 402.78 0.91
1 5 17 405.25 403.46 1.79
6 15 404.51 403.58 0.93
6 16 405.25 403.59 1.66
7 10 409.50 405.40 4.10
7 11 409.76 405.48 4.28
' 8 12 402.45 402.41 0.04
i
1
1
1
1
i
American Engineering Corporation Page 26
Technical Information Report for Ridgeview Court May 12, 2005
' SECTION 6 SPECIAL REPORTS AND STUDIES
A wetlands study has been prepared by Alder NW dated March 13, 2003. Also, a geotechnical
report has been completed by GeoGroup Northwest dated October 4, 2004. No other reports or
studies pertaining to this project are known at this time.
1
i
American Engineering Corporation Page 27
Technical Information Report for Ridgeview Court May 12, 2005
SECTION 7 OTHER PERMITS
' A separate building permit will be required for the detention vault and rockeries greater than 4
feet. Furthermore, a demolition permit will be required for removal of all existing buildings on
site. No other permits are anticipated as part of this project at this time.
1
American Engineering Corporation page 28
Technical Information Report for Ridgeview Court Mav 12, 2005
' SECTION 8 ESC ANALYSIS AND DESIGN
' Several standard erosion control procedures will be utilized by the contractor to minimize the
amount of erosion and sedimentation perpetuated by the construction of the site. Some of the
measures include a rock-lined construction entrance, filter fabric fence, a temporary sediment
1 trap and standard ground cover practices. A construction sequence will also be used to minimize
the impacts of erosion due to construction. These items will be discussed in further detail when
the construction / final engineering plans and final TIR are submitted to the City of Renton for
review.
Clearing Limits: T he c learing 1 imits h ave b een c learly m arked and w ill s how the contractor
where site disturbances should occur.
Construction Entrance: A rock lined construction entrance will reduce the amount of sediment
transported off the site by construction vehicles.
Detain Flows: The permanent vault and or temporary sediment pond will be used to remove
sediment from the runoff generated by the disturbed areas during constriction. The vault has
been sized per 1998 KCSWDM requirements. Refer to Section IV for more information.
Sediment Controls: Filter fabric fence will be used as perimeter protection to reduce the amount
of sediment transported off the site.
' Soil Stabilization: Notes have been added to the engineering plans, describing how denuded
areas will be treated if left un-worked for longer than 7 days.
Slope Protection: Slopes will be protected once final grade has been achieved or left un-worked
for longer than 7 days.
Drain Inlet Protection: Catch Basin Inserts will be installed once the final storm system is
installed. Furthermore, inserts will be installed on all catch basins adjacent to the site on Forbes
Creek Drive as shown on the Engineering Plans.
Stabilized Channel Inlets and Outlets: If necessary, temporary and permanent BMP's may be
' required for pipe outlets and inlets. These BMP's may include but are not limited to filter fabric
fence, straw bales, or filter bags at pipe ends.
' Pollutant Control: With the BMP's mentioned above, the pollutants should be kept to a
minimum during the construction process.
' De-Watering Control: A temporary riser in the sediment pond or the permanent riser in the
vault will be used for the de-watering control. Refer to "Detain Flows"above for more
information.
' American Engineering Corporation Page 29
Technical Information Report for Ridgeview Court May 12, 2005
' BAIP's Maintenance: Temporary and permanent BMP's shall be maintained per the proper
maintenance standards.
' Construction Sequence: A construction sequence has been shown on the final construction
plans to aid the contractor in applying the different erosion control measures at the appropriate
stages during construction.
Sediment Trap Sizing:
SA=2 x Q10-year/ 0.00096
where SA= required surface area at top of riser
Q10-year= 0.607 cfs
SA= (2 x 0.607) / 0.00096 = 1,265 sf
As proposed the temporary sediment trap contains 1,655 SF at the maximum water surface (@
' elev. 403). Therefore, sufficient surface area has been provided.
Emergency Overflow Spillway Sizing:
L= [Q(IOOYR)/ ( (3.21)(H3/2) )] —(2.4) (H)
L=Length of spillway(6 foot min. allowed) - see below
Q(looYR)= 100 year developed flow— 1.02 cfs
H =Height above head - 0.2 ft
L= [1.02 / ( (3.21)(0.23/3) ) ] — (2.4) (0.2) = 3.1 feet
Since the developed site produces such small flows, the required length of the spillway structure
is below the minimum length (6-feet). Therefore the proposed spillway as designed has a length
of 6 feet.
American Engineering Corporation Page 30
' Technical Information Report for Ridgeview Court May 12, 2005
i SECTION 9 BONDS, SUMMARIES AND COVENANTS
' A bond quantity worksheet, and facility summary information will be provided to the City of
Renton after first review of the construction/ final engineering plans.
' American Engineering Corporation Page 31
f
' Technical Information Report for Ridgeview Court May 12, 2005
SECTION 10 OPERATIONS AND MAINTENANCE MANUAL
The storm drainage elements requiring maintenance attention include: detention vault, wetvault,
Type 1 and 2 catch basins, and all storm conveyance lines. The detention/wetvault facility
located within the separate public Tract shall be maintained by the City of Renton.
' The operation and maintenance guidelines can be found in Appendix E.
t
American Engineering Corporation Page 32
Q
w
j r '_�M1.- a •a, ° 1,I .. .rl li � � (- •J' __/
j li f
1 1�.�
I
.•'" � I, � i ,,, 1 _ � �':III _''•'.}�
1
/r tl
if
I
r t- m ��
r ... D
if
If
Fn
3
r^ � I -•Ij� i -_" �` �f ? ,T :-.;1��• 1' � /, ,i
+ I (, •`�. �J �r � f tl �j
j i t w_ � ) rlTt r, i •� rl 'r I�J t� ( � r � ,f 1 �i: . •
�..-�:.,�-- r el r r If "� rt ) j d tr r •i
.0 11
d_. ��i ��� r si ,'.1> ••c1 rl s T rti I
to
I � r( .q '•. i / o i
Ar
ol
r II Ir551ts ' i
C 0 /I 1
�� II � ,`,t rl is •t •�I'
Z I
a
m
M
C cn
L � 1
\—... � � � �III�� —�`\�� ^ `. d»nY Grer \ `• _ _ ���- -, - J _ ...- �_
T.
ISH
V A T 1 O 11.A E O" f S T"-
- L•—
Nont.folk
�\ - SROD,Wmh MrE1 ` t
drto�Gr ii _ `'0 t {
- : AIM 5
RIVER
PUGET �..Mall �-� - - -
�- �Or , /SeoeaAlm Piwr
3-1 t' .1�. _ �� A+YY'D wr. 'r i - F.......... - •_ •_-._ `a
sou
i -�- OSE Yee1n
Fbw 6. i _. Figure 2
DRAINAGE BASINS
1 = _ DRAINAGE - = j Mw t CITpiSEAT lE1UTE11SME0 King County
1985
-.;. Major Basin Boundary
Ji
} .y„ �•��._ .._.�_; •�» �l" �,GP. r, �.�• .� i Sub-Basin Boundary
�- •'� Source: King County Sensitive Areas
'"__ Map Folio,Wetlands Supplement
. { CT OF TACOMA WATERSHED - �•
+ _
BASIN - }
`E 0 1 2 3 4 5 6 7 a Miles
1:300,000 t/90
-� 3.2.2 KCRTS/RUNOFF FILES METHOD—GENERATING TIME SERIES
' TABLE 3.2.2.11 EQUIVALENCE BETWEEN SCS SOIL TYPES AND KCRTS SOIL TYPES
SCS Soil Type SCS KCRTS Soil Notes
' Hydrologic Group
Soil Group
—� Aiderwood (AgB, AgC, AgD) C Till
' Arents, Alderwcod Material (AmB, AmC) C Till
Arents. Everett Material (An) B Outwash 1
' Beausite (BeC, BeD, BeF) C Till 2
Bellingham (Bh) D Till 3
Briscot (Br) D Till 3
' Buckley (Bu) D Till 4
Earimont (Ea) D Till 3
Edgewick (Ed) C Till 3
Everett (EvB, EvC, EvD, EwC) A/B Outwash 1
Indianola (InC, InA, InD) A Outwash 1
Kitsap (KpB, KpC, KpD) C Till
' Klaus (KsC) C Outwash 1
Neilton (NeC) A Outwash 1
Newberg (Ng) B Till 3
Nooksack (Nk) C Till 3
Norma (No) D Till 3
Oroas (Or) D Wetland
' Cridia (Os) D Till 3
Ovall (OvC, OvD, OvF) C Till 2
Pilchuck (Pc) C Till 3
Puget (Pu) D Till 3
' Puyallup (Py) B Till 3
Ragnar(RaC, RaD, RaC, RaE) B Outwash 1
Renton (Re) D Till 3
' Salal (Sa) C Till 3
Sammamish (Sh) D Till 3
' Seattle (Sk) D Wetland
Shalcar (Sm) D Till 3
Si (Sn) C Till 3
Snohomish (So, Sr) D Till 3
' Sultan (Su) C Till 3
Tukwila (Tu) D Till 3
Woodinville (Wo) D Till 3
' Notes:
1. Where cuNvash soils are saturated or underlain at shallow depth (<5 feet) by glacial till, they should
be treated as till soils.
' 2. These are bedrock soils, but calibration of HSPF by King County DNR shows bedrock soils to have
similar hydrologic response to till soils.
3. These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water
' table. In the absence of detailed study, these soils should be treated as till soils.
4. Buckley soils are formed on the low-permeability Osceola mudflow. Hydrologic response is
assumed to be similar to that of till soils.
' 1998 Surface Wa[er Design Manual 9/1/98
3-25
JUL-21.2004 4:2�5PM KC WLRD N0.941 P.1/4 --
' Kinsz County Water and Land Resources 'AZ Rl Division
201 S Jackson St, Suite 600
' Seattle, WA 98104-3855
Date:FAX G
Number of pages including cover sheet:
To
From: Cindy_Torkelson
Fax: VVIR Stormwater Services Section
Phone: c� — Phone: 206-296-1900
Fax Number: 206-296-0192
IMPORTANT LEVEL 1 ANALYSIS NOTE: We do not send copies of certain
complaint types that are not relevant such as BCW, FI, FIR, FIH and WQA, and
we do not send CL and LS types. See key below. Type S 1, S2 and S3 will not be
faxed'due to size constraints.
The following is a list of complaint types received by the Water and Land Resources Division Drainage
Services Section. Complaint numbers beginning prior to 1990-XXXX have been archived and are no
' longer in our possession. They can still be retrieved, if necessary, but will take additional time and may
not be beneficial to your research due to their age, development which has occurred, etc. If you are
interested in reviewing the actual complaints, they can be pulled(time permitting) for your review.
' Copies can be obtained for$ .15 per page, and$2.00 per page for plans.
TYRO Keys:
of i(nvCsti ati n Tv Re of Problem
C Aetion Request DCA DeveloprncndConstruction
BCW Susiness'for Clean Water DDM Drainage-Miscellaneous
CCF R-spouse to Inquiry DES Drainage—Erosion/Sedirnenration
CL Claim DLE Drainage—Landslide/Earth Movement
EH Enforcement on Hold DTA Drainage Technical Assistance
' ER Bnfore mentRevie,v Qv'Q Drainage—General Inquiry
FCC,FCR,FCS Facility Complaints MMA Maintenance-Aesthetes
FI SWM, Fee Inquiry MMF Maintenance-Flooding
FIR SW-M Fee Review MMG Vaintenarcc-General
FIR SWM Fee on Hold MMM Maintenance-Mowing
' *IS Lawsuit NMI Maintenance—Needs Maintenance
RR Facility Engineering Review MNIAr Maintenance-Noxious Weeds
NDA Neighborhood Drainage Assistance SWT SWM Fee Questions
W'QC Water Quality Complaint WQB water Quality—Best Management Pnctieec
' «'QF Water Quality Enforcement WQD Wattr Quality—Dumping
WQR Water Quality Engineering Review WQI Water Quality—Illicit Connection
WQA Water Quality Audit REM SWNt Fee•Remcasurement
WQO Water Quality—Other GRT SW-MPce-Grant
' S1,S2,SN3 Engineering Studies NWD SWM Fee-Near Discount
"Subject to Public Disclosure requirements 1.Receipt of written request for documents 2.Review and approval by prosecuting Attoney's office
JUL-21.2004 4:25PM KC bJLRD NO.941 P.2/4
' No County Water and land nesouroas division-Drainaos Serulces Sectlon
Complaint Search Printed: 7/21/2004 2:30:44 PM
' compunt T}rpe Type of Problem Address of Problem
Number Code Communts H,oa P*
"49�5.9a36--C FLOG 13921 SE 138TH PL' SWAMP/SE 138TH PL/WfDEWAY HTS G56J2 1gA1.r11��r DRNG 13832 SE 131$TST BLKED
FLOG 14005 SE 133RD ST 656.2
DRNG 12808 138TH AVE SE 656,2
' & FLDG
•4 4 G. FLOG 14009 SE 128TH ST MAPL EWOOD HTS 656J2
656J2
OVR 16935 116TH AVE SE @ SE 132ND/144 T H AVE SE 656J2
' 883.es5a E, FLDG 13224 144TH AVE SE"
656,12
DVR 140YX SE 132ND,ST'.i' "- . .:.. FLOG
1gR5-141n« DRNG 14100 SE 132NO ST SE G56J2
E 84-1005IT0 ROADS 656J2
DRNG 14011 SE 132ND S7 SURFACE WATER' 656J2
..4.9g6.Q25R F G56J2
' F98&-OAS 1 656.12
COMMITTED DATE:IST QTR 1989. 656J2
V�-03A4--.E
-�386-63R�k-t DRNG 138TH AVE 5E SYSTEM SILTED 656J2
' PROS CRTD. 656J2 FLOG 13323 14�TH AVE SE WATER FROM SCHOOL 656,12
117=@Ys C FLOG 14639 SE 132ND ST STANDING WATER& MUD 556J2
' 19J7-03�8-C DRNG 13323 146TH AVE SE CO DIVERTED DRNG ONTO PROPERTY 656,12
t9ai, e4e5--e FLOG 13025 138TH AVE ' SE SEE 87-0463 OVER STREET 656J2
1987.0445 C FLDG 13837 SE 128TH$7. , FILLING OF LOT
1987-0445 ER FLOG 13837 SE 128TH ST 656J2
SEE 88-b3A4 PENTON. 87-0707 656J2
FLOG 13025 138TH AVE SE ON 1387H AVE SE 656J2
DRNG 14106 SE 135TH ST STRORM DRAIN FAILURE 656J2
i?89-eB3$--e DEBRIS 14003 SE 132NO ST DEBRI ON RD TO DET POND 656,12
3,C DRNG 13852 SE 128TH AVE DRAINAGE OF NEIGH60RS FILL/ROAD CO. 656.12
SETTLING 13120 138TH AVE SE SINK HOLE IN YARD 656J2
-9-49-09&1-42 FLDG/DVR 14011 SE 132ND ST SEE:86-0256 YAHN PH I 656J2
1858=04';L2� INQUIRY 14105 SE 133RC ST STATUS OF STUDY(YAHN STUDY) 656,12
188 $gS6'K' DRNG 14103 SE 132NO ST YAHN STUDY COMPLAINTS 656J2
FLOG 14639 SE 132ND ST DITCH OVERFLOW/STORM EVENT 656J2
1 '_C DRNG 14105 SE 133RD ST FLOODING IN NBRHD 658,12
1990-0512 C DRNG 13600 1387H AVE SE CROSS PIPE ERODING RAVINE 658,12
199A-656�-G DRNG 13323 1467H AVE SE DITCH ENDS/DIVERTED WATER 655J2
1998 e558-1=R DRNG 13323 148TH AVE SE XPIPE AND POND/DITCH ENDS 655J2
' FLOG 14105 SE 133RO ST COMPLETION OF STUDY 656J2
1° -1 O FLOG 14105 SE 133RD ST CAPACITY OF PLAT DRNG 856J2
t6gi-eeet--sTr DRNG 14105 S 133RD ST PUGET COLONY HOMES 656J2
' ;, Page 1 of 3
JUL-21.2004 4:26PM KC WLRL1 NO.941 P.3/4
Complaint Type Type of Problem Addrees of Problem
' Number Cade Comments Tbros Pape
1.99 -00✓� DRNG 14105 S 133RD ST CCF#191-32/YAHN STUDY/FLOODED YAP, 656J2
' 1391-6@96--SR DRNG 14105 SE 133RD ST C.CF#SWM0124 PUGET COLONY HOMES 656J2
4884-999 x DRNG 14105 SE 133RD ST CCF#SWM0124/OEVELOPEMEN
46--9- DRNG 14013 SE 133RD ST 656J2
PLUGGED 656J2
1991-t245—r. DRNG 14013 SE 133RD ST PLUGGED PUGET COLONY HOMES 656J2
FLOG 14011 SE 132ND OI JERSI 656J2
ON/CI,LVERT OVERFLOW
1991-0619 NDA. DRAINAGE 10403 147TH AVE SE STORM EVEN;- DNU FLOODING 656,12
' A FLOG 14105 SE 133RD ST CCF#491.32 NOT NDA PUGET COLONY H 656J2
489t-es FLOG 14105 SE 133RD ST CCF#491-32/PLAT DRAINAGE 656J2
't984�P A DRNG 14105 SE 133RD ST. CCF#591-2 NOT NDA PUGET COLONY HO 656,12
179t-t"0--C DRNG 14105 SE 133RD ST CCF#591-2 SAME OLD PROB 656J2
1994-9552—C`t FLOG 14105 SE 133RD ST- ^ - " - -CCF#591-2 DUE JULY 6564
" DRNG 14103 $E 132NO ST CCF#SWM 0520 NOT NDA PUBET COLON 656J2
49g4.9 �C DRNG 14103 SE 132NO ST CCF#SWM 052C MANY COMP 656,12
•139t-9ftl-� DRAINAGE 14105 SE 133RO ST NEIGHBORHOOD FLOODING 856,12
1131-0715—SR DRAINAGE 14105 SE 133RD ST PUGET COLONY HOMES 656,12
14Q4-4Z2Z--SR DRAINAGE 14105 SE 133RD ST CCF#591-37 PUGET COLONY HOMES 656,12
f-19 3- DRAINAGE 14105 SE 133ROST CCF#591-37
656,12
DRAINAGE 14024 SE 133RD ST /LAMB (CLAIM) 656.12
SR DRAINAGE 14024 SE 133RD ST /IAMB (CLAIM) NOT NDAP 056,12
4 - R DRNG/FLD 14103 SE 132NO ST CCF#SWM-0610 NOT NDAP 656.12
' 1694-=7-449A FLOODING 14103 SE 132ND ST CCF#591-39 NOT NDA PUGET COLONY 656,12
ti —X FLOODING 14103 SE 132ND ST CCF#591-39 656,12
1 —G DRAINAGE 14639 SE 132ND ST 656J2
189+-6868--SR DRAINAGE 14010 SE 134TH ST CCF#SWM0279 NOT NDAP 6562
1191-C858 DRAINAGE 14010 SE 134TH ST CCF#SWN10279/PUGET COLONY 656,12
I *9911 0885—x FLOODING 13405 142ND AVE SE CCF#SWh4-0854/DRAINAGE IMPROVEME e56,12
- FLOODING 13800 SE -28TH ST CCF#SWM-0852-N07 NDA-PUGET COLON 656J2
FLOODING 13600 SE 128TH ST CCF#SWM-0852WETLAND PROBLEMS 656J2
4994.6946--X DRAINAGE 14105 SE 133RD ST CCF#:'91-0822/GRANTING EASEMENTS 656,12
19844�X DRAINAGE 14105 SE 133RD CCF#SWM 1217/PROJECT SCHEDULE 656J2
t99s*tT9 C DIVERSON 137XX 144TH AVE SE POSS CLEARING VIOLATION 656J2
'199.34)Z24- C PONDING 12217 148TH AV SE POSSIBLE SAO ViOLATION/DITCH ENCRO 656.11
INQUIRY 14105 SE 133RD ST INFO ONLY 656H2
1494-944—J—' FLOG 14400 SE 136TH ST GROUND WATER UNDER ROADWAY 656,12
199s1-CQ -� DRNG 14600 SE 132ND ST CHKSTATSYCMDT 656.12
199e-fia&&—ER DRNG 14600 SE 132ND ST 656J2
19$6-9�63--e- VACATION 14010 SE 134TH ST DRAINAGE IMPACT FROM VACATION REQ 656H2
' �4955-8�86--C DISCHARG 14328 SE 128TH ST COMPLAINT REQU NO INV(g THIS TIME 656J1
4�-}--WQC DUMPING 12516 142NO AVE SE APPARENT PROPERTY DISPUTE 85611
r
Page 2 of 3
JUL.21.2004 4:27PM KC WLRD NO.941 P.4i4
1
Camplamt TyA8 Type of Arodlem Address of Problem
1 Humber cads comments Tbros Page
"9e-N4O�QC EROSION 14328 SE 128TH ST
CIP 140TH SE 132NO-135TH 656J1
SE REQUEST TO DO ASSESSMENT OF CONV 656H2
19943-�z9�--C MFLVIDTRS 128TH SE & 149TH AVE SE DOWNSTREAM IMPACT TO ROAD CROSS 6561-11
—C FLOG SE 128TH& 142ND A SE MAINTENANCE OF EXISTING CHANNNEL 65611
1 "' '—C FLOG 14105 SE 133RD ST PUGET COLONY HOMES
—-LQA Z-C-5--NDA FLOG 14105 SE 133RD ST 656J2
PUGET COLONY HOMES 656,12
4997 eei5 FLOG 14105 SE 133RD ST PUGET COLONY HOMES
' 1QQZXZ F R RID FENC 13845 SE 131ST ST TREE656J2
DAMAGED FENCE ROADS FACILITY 656H2
1�9'1"i•3T8-"C DRAINAGE 14004 SE 133RD ST LOCALIZED DEPRESSION PUGET COLON 656H2
' �39't'tST�—Iq' DRAINAGE 14004 SE 133RD ST LOCALIZED DEPRESSION PUGET COLON 6561-12
DRAINAGE 14005 SE 133RD ST LOCALIZED DEPRESSION PUGET COLON 6561-12
DRAINAGE 132XX 140TH AVE__ .,,OFFSITE CONVEYANCE DRAIN QUEST CH 656H2
19AZ-1850.5 0 QA BMP'S 14413 SE 128TH ST
1 C DRAINAGE 14454 SE 132NO$T 656.11
APPEARS PRE GRADING ACTIVITY NO PE 656,12
3Z—WQC WASHWAT 13224 144TH AVE SE APPARENT GREY WATER DISCHARGE 656,12
' I95Q-v0J4—n QR WQI 13224 144TH AVE SE APPARENT GREY WATER DISCHARGE 656J2
432 -09 015_ R DRAINAGE 14013 SE 133RD ST
""420Z—CL DRAINAGE 14004 SE 133RD ST 656H2
RECORD OF INQUIRY ONLY-NO CLAIM 656H2
CONSTRUC 14606 SE 136TH ST CONCERNS RE NEW DEVELP CITY OF RE 656J2
STND H2O 13741 148TH Pl. SE SOGGY BACKYARD SOURCE OF WATER 656,12
2 —C DCA 14100 SE 132NO ST' NO FIELD INV NECESSARY. REF'D TO SW 6561-12
—1;9 -CTe3' FCR MNM 14004 SE 133RD ST
DDM DAMAGED FENCE GATE AT UNOPENED R/ 656H2
13309 146TH AVE SE
,2WZ Q6—CL INQ 140t2 SE 133RD ST 656J2
:... . . -, FENCE DAMAGED 6Y TREE FALL. TREE G 656H2
2nn '—I DTA 140TH A & SE 132NO ST
2004-84eT—I DOM 14012 SE 133RD ST , 656J2
656H2
i
1
1 '
1
1
Paga 3 of 3
1
1
A
W
d
CJ ( 7J
1
AlderNW
March 13, 2003
Project No. 21803
Mr. Robert Wenzl
P. 0. Box 2401
Kirkland,Washington 98083-2401
Subject: Site Observations
' Property at 12905 136th Avenue SE
Renton,Washington
Tax Parcel No. 5182100042
' Dear Mr.Wenzl:
' As requested we have conducted a wetland evaluation study for the property located at 12905 136th Avenue SE, in
the City of Renton, Washington. The purpose of this work was to complete a site evaluation to make a determination
if wetland conditions are present on or immediately adjacent to the property.
Our scope of work included a site visit on February 19, 2003, at which time we completed our site evaluation. In
conducting our site evaluation, we followed the general procedures for the routine on-site methodology as outlined in
the March 1997 Washington State Wetlands Identification and Delineation Manual. This procedure involves analysis of
vegetation patterns, soil conditions, and near-surface hydrology in making a determination of wetland conditions.
PROCEDURES
For the purpose of this study, we used the wetland definition adopted b the Environmental Protection en PA
Y Agency(EPA)
and the Army Corps of Engineers (COE) for administering Section 404 of the Clean Water Act. According to this
definition,wetlands are:
"those areas that are inundated or saturated by surface water or groundwater at a frequency and
' duration sufficient to support, and that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil conditions. Wetlands generally include
swamps, marshes,bogs, and similar areas." (33 CFR 323)
' In Washington State, the Shoreline Management Act and Growth Management Act have amended this definition to
exclude some wetland situations by adding the following sentences to the wetland definition:
' 518 North 59t+ Street Seattle Washington -as ngton 98103• Phone (206)783 1036 email aldernwpaol.com
' Mr. Robert Wenzl
March 13, 2003
' Wetlands do not include those artificial wetlands intentionally created from non-wetland i s tes,
including but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention
facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands
created after July 1, 1990, that were intentionally created as a result of the construction of a road,
street or Highway. Wetlands may include those artificial wetlands intentionally created from non-
wetland areas to mitigate the conversion of wetlands.
Delineation procedures are based on diagnostic environmental indicators of wetland vegetation, wetland soils, and
1 wetland hydrology. These procedures, outlined in the Washing on State Wetlands Identification and Delineation
Manual (March 1997) are commonly known as a Triple Parameter Method. By definition, an area is designated as
wetland when there are positive indicators for all three parameters.
A listing of plant species has been developed for use in the methodology for delineating wetland areas. This listing
assigns plant species to one of five indicator status categories ranging from Obligate wetland species, which almost
always occur in wetlands, to Upland species, which rarely occur in wetlands. Under normal conditions, hydroph5tic
vegetation is determined to be present if more than 50 percent of the dominant species are in the Obligate (OBL),
' Facultative Wetland(FACW), or Facultative (FAC) indicator categories.
Diagnostic indicators of hydric soils are relaxed to soil saturation, which leads to anaerobic conditions in the soil.
Under these conditions, decomposition of organic material is inhibited and soil minerals are reduced, creating
characteristic soil colors that can be quantified by comparison with Munsell Soil Color Charts. A chroma of one or
less in unmottled soils or a chroma of two or less in mottled soils generally indicates a hydric soil. In addition, soils
that are saturated during the growing season satisfy a criterion for hydric soils. We used a hand auger to excavate
' shallow test pits to observe soil conditions to depths of 24 to 28 inches.
Wetland hydrology is defined as inundated or saturated soil conditions for at least 14 consecutive days during the
' growing season. If no water is present at the time of evaluation, other indicators may include topographic low points
or channels, flood debris, complete absence of vegetation, or presence of hydric soils.
' Standardized data forms are available to record observations on each wetland parameter. For this project, we
completed data forms for the Routine On-Site Determination Method at two representative locations on the site.
' Copies of these data forms are included with this report. The format of the data forms is based on the forms for the
Routine Wetland Determination from the Washington State Wetland Delineation Manual and the 1987 Corps
Wetland Delineation Manual. Additional observations of soils, vegetation and hydrology, beyond those reported on
the data forms were used in completing the site evaluation.
' SITE CONDITIONS
The subject property is a rectangular shaped property of approximately 2.3 acres. It is located at 12905 — 136th
Avenue SE in the City of Renton. There is an existing single family residence on the property along with several
outbuildings.
Project No. 21803
' Page No. 2
' Mr. Robert Wenzi
March 13, 2003
' The adjacent property to the south i l p perry s occupied by a construction company and is in use as equipment and material
storage yard. Adjacent properties to the north and east are occupied by single-family residences. The property off
the northwest comer is operated as a U.S. Postal Service facility and the property off the southwest property comer
is undeveloped.
Soils on the property and over much of the surrounding area are mapped as Alderwood gravelly sandy loam on the
(Soil Survey of King County, Washington, U.S. Soil Conservation Service, 1973). Alderwood soil types are
' included on the National Technical Committee on Hydric Soils listing of hydric soils. Our observations of soil
conditions across undisturbed sections of the property are generally consistent with the descriptions of the Alderwood
soil types. There has been grading and filling on the southern portion of the property,and on the area surrounding the
existing residence. Based on the growth of trees on the property it appears that the fill on the property was placed
more than 15 years ago.
Topographically, the property is generally slopes down from the south and north to a broad swale crossing the middle
section of the site.
' Vegetation on the site reflects the use of the property. The southern half of the property is grown up in a stand of
black cottonwood (Populus balsamifera) trees with an understory of Himalayan blackberry (Rubus discolor),
' hardhack spirea (Spiraea douglasii), with scattered Douglas fir (Pseudotsuga menziesii), and western red cedar
(Thuja plicata)trees present. The central low section of the property is occupied by dense Himalayan Blackberry.
' A system of graded driveways presently vegetated in short grasses loop around the property. There are scattered
standing Douglas fir, big leaf maple(Acer macrophyllum)on the site.
IThe attached Data Forms identify conditions on the southern section of the site. These locations were selected as low
areas on the site where vegetation was indicative of somewhat wetter conditions. As noted on the data forms soil
conditions were not indicative of long term saturation and there was no water table within the upper 18". Conditions
' noted on the data forms are representative of other areas across the southern and lower sections of the property.
Based on our site observations and the application of the wetland deterniination methodology, it is our interpretation
that there are no wetland areas or streams on the site or in the inunediate vicinity.
We trust the information presented is sufficient for your current needs. If you have any questions or require
additional information,please call.
' Sincerely yours,
ALDER NW
Garet P. Munger
Project Scientist
i Encl.: Vicinity Ma
_ P
Data Forms (3)
Project No. 21803
Page No. 3
DATA FORM
' ROUTINE ON-SITE WETLAND DETERMINATION
Describe General Site Property has been graded in the past and is Data Point No.: DP-1
Conditions: grown up in blackberry and young alder and
cottonwood.
' Site Disturbance? Location: Southern section of
property in low area
VEGETATION
Cz
ca
Dominant Plant Species.._ Cq Dominant Plant Species
Cz
1 Spiraea douglasii FacW S 8
2 Phalaris arundinacea FacW H 9
3 Graminae H 10
4 Populus balsamifera Fac T 11
5 12
' 6 1131
14
Percent of dominant species that are OBL, FACW, and/or FAC: 100
' Is the hydrophytic vegetation criterion met? Yes Rationale: More than 50'0 species hydrophytic
SOIL
Soil Type: Alderwood (old fill?) Hydric Soils List: No
' Histic Epipedon? no Mottles? No Gleyed? No
Matrix Color: IOYR414 Mottle Colors: Depth: 12"
Other hydric soil indicators: No
Is the hydric soil criterion met? No Rationale: Chroma greater than 2
1 HYDROLOGY
Is the ground surface inundated? no Surface water depth:
Is the soil saturated? No
Depth to free-standing water in probe hole: No
Other field evidence hydrology: No
Is the wetland hydrology criterion met? no Rationale: Non hydric soils
' WETLAND DETERMINATION
Are wetland criteria met? no
Rationale for wetland decision: Non hydric soils; no evidence of long term soil saturation on disturbed site
Project Name: Wenzl Renton Property A1derNW
Field Investigator(s): G.Munger 518 North 59th Street
Project No.: 021703 Date: 2/19/03 Seattle,Washington 98103
DATA FORM
ROUTINE ON-SITE WETLAND DETERMINATION
Describe General Site Property has been graded in the past and is Data Point No.: DP-2
Conditions: grown up in blackberry and young alder and
cottonwood.
Site Disturbance? Location:
VEGETATION
Dominant Plant Species U � L Dominant Plant Species
� Cz
C � C
1 Populus balsamifera Fac T 8
2 Phalaris balsamifera FacW H 9
10
4 11
5 1 1 1 1121
5 1 1 1131
14
Percent of dominant species that are OBL, FACW, and/or FAC: 100
Is the hydrophytic vegetation criterion met? yes Rationale: Greater than 50•16 species hydrophytic
SOIL
Soil Type: Alderwood (old fill?) Hydric Soils List: no
Histic Epipedon? no Mottles? No Gleyed? No
Matrix Color: JOYR413 Mottle Colors: - Depth:
Other hydric soil indicators: No soil is disturbed with some fill placed.
Is the hydric soil criterion met? No Rationale: Chroma greater than 2
HYDROLOGY
' Is the ground surface inundated? no Surface water depth: -
Is the soil saturated? No
' Depth to free-standing water in probe hole: Not in upper 18"
Other field evidence hydrology: No
Is the wetland hydrology criterion met? no Rationale: No water in upper 12", no evidence of saturation
' WETLAND DETERMINATIONAre wetland criteria met? No
Rationale for wetland decision: Non hydric soils; no evidence of long term soil saturation on disturbed site
Project Name: Wenzl Renton Property AlderNW
' Field Investigator(s): G.Munger 518 North 59th Street
Project No.: 021703 Date: 2119103 Seattle,Washington 98103
1
DATA FORM
ROUTINE ON-SITE WETLAND DETERMINATION
Describe General Site Prosperity has been graded in the past and is Data Point No.: DP-3
Conditions: grown up in blackberry and young alder and
cottonwood.
' Site Disturbance? Location: Low point of Swale
along east side ofprop.
VEGETATION
Dominant Plant Species Dominant Plant Species
1 Rubus discolor up/ S $
2 9
' 3 10
4 11
5 12
' 6 1 13
7 1 14
Percent of dominant species that are OBL, FACW, and/or FAC:
Is the hydrophytic vegetation criterion met? Rationale:
SOIL
Soil Type: Alderwood(old fill) Hydric Soils List: no
Histic Epipedon? no Mottles? No Gleyed? No
Matrix Color: 10YR4/3 Mottle Colors: - Depth:
Other hydric soil indicators: No
Is the hydric soil criterion met? No Rationale: Chroma greater than 2
HYDROLOGY
i Is the ground surface inundated? no Surface water depth:Is the soil saturated? No
' Depth to free-standing water in probe hole: Not in upper 18"
Other field evidence hydrology: no
Is the wetland hydrology criterion met? no Rationale: No water table present in upper 12"
' WETLAND DETERMINATION
Are wetland criteria met? no
Rationale for wetland decision: Non hydric soils; no evidence of long term soil saturation on disturbed site
Project Name: Wenzl Renton Property A1derNW
Field Investigator(s): G.Munger 518 North 59th Street
Project No.: 021703 Date: 2119103 Seattle,Washington 98103
DOSS; t5 oao °... 901', Q23
r'2='G �..G 178
-A76S C)"%4&0640 S,y,0335
6t2p H Pm CtiSAS� NE f.TH STD
' Yr- - -- - --- ..._-._ - -- — - -
2 9.d9 9t?4 623b 9QS• a•_ ENE fiTH.ST= SE_424TH 5T,Ct_
ZNE_STH.P� 9 ^5 ►�+� Z- =Gd30 9385 t90
_ .
g G37 t 3 -
-Q r- - _ _ CH'R} n�.. G'23 5tSS9 g �-
' �0? 2 C 4 Q. NESTH gT aZ w i l?�N.5.
.
O r IW
41 Z . y. _ -- - - Z_
d .— m Q '6 929 tr CU z
_
rn
9,64 rn 3 126TH ST m
' 5044 5'9Bth
Q 5°2dt n' =91E+S m
t 1M 28 9 'b6 was �. I
sto•
C030 2 9Qt2 -.0 77 -
Lz31 9:t7 S
e�339t97 9t Q 9t'2 9374. C-34Q rn 903
7440 -- - _
C� -
-- __ NE_4TH 57 ._ ---rn
3303 r M9SQ
-- - MI:- - ff o!
9r�8A
nc
9325' 4G89 7 0039 r 2 9t 2 -
- /its C44 gr - 9145
OQ48 & Sid0 Wot qp�c
72 9178
-- • SL:1 e w 9034 -T..--
QOt3_.
- 9124 0@tS+kT44. Ca42 a!: on"e,
-- -
- - 5,4r2 - - - _-`
4 2_ tai
9W Ocat
�2t 9020 9'25Ocw o-y 2 2 9075� Sr'�c2,'
Con fk.@5 Qlx i y °r
92tt ��jx
ono O 1A��8 02' .•. --- - --- _734g7_gL __-__ "_d08d °2tS 92f+5 0�3 �c3
cQ5? 42,3 9 f -- -- 92"8
9t•53 _ 211 '— �yJe �•J 02.0
NE2ND_gt __SE 432ND gT gng8 —QhJ ol°2
_ _9981 907ao5w 1L _C4470 -- -- --SE 132ND_5T _BE 432ND ST
a72++ _ w
40
0.
Nf 1ST PL [CtSQ SE 13.JRp
^rl.+32w
�f9 _ 02ta O7_C� n S'-- rn• 6 03.,3 r•,yst 50
5'02 ..-•-W j� gE tgT_- - SE.' rl3G °•$ - "3�r}- 134TK ST t
gls
;—
_._N=2 in, - : C.V-.T✓t.•.GJt�
r','6,� `-1:`J CPd?t+4S0 2
9;DT >:0270 YASHO L�SfiA rn�C SE_135TH BIT i
iQ280 - _ N ,SE Sfa4Q -- - -SE135Ty ST- >.--
o na GasG
9 -- _� a 3ti 'azm, .
— ex� a32e M
`!s64 9C78S ]OJda gE?JVD PL t_ V 9'29'a 00 0'4G _ p3?t, C►'M tf>vt+
-
jcJ20021ONBCOIINTY136THtST
he information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice.
ng County makes no representations or warranties,express or implied,as to accuracy,completeness,timeliness,or rights to the use of such
formation.King County shall not be liable for any general,special,indirect,incidental,or consequential damages including,but not limited to,
st revenues or lost profits resulting from the use or misuse of the information contained on this map.Any sale of this map or information on
is map is prohibited except by written permission of King County.
VICINITY MAP
ALD Wenzl—Renton Properly
i
ERNVV Renton, Washington
Project No.011703 1 Dote Feb, 2003 1 Figure 1
H
A
W
a
i
i
GEOTECHNICAL ENGINEERING STUDY
' PROPOSED RESIDENTIAL DEVELOPMENT
12905 136TH AVENUE SE
RENTON, WASHINGTON
G-1846
i
Prepared for
Mr. Robert Wenzl
Vineyards Construction, LLC
P.O. Box 2401
' Kirkland, WA 98083-2401
' October 4, 2004
GEO GROUP NORTHWEST, INC.
i13240 NE 20" Street, Suite 10
Bellevue, Washington 98005
' Phone: (425) 649-8757
Email: info@geogroupnw.com
1
' Geotechnical Engineers,Geologists
Group Northwest, Inc• &Environmental Scientists
October 4, 2004 G-1846
' Mr. Robert Wenzl
' Vineyards Construction, LLC
P.O. Box 2401
Kirkland, WA 98083-2401
SUBJECT: GEOTECHNICAL ENGINEERING STUDY
PROPOSED RESIDENTIAL DEVELOPMENT
12905 136TH AVENUE SE
RENTON, WASHINGTON
' Dear Mr. Wenzl:
Geo Group Northwest, Inc. has completed an investigation of subsurface soils at the above
referenced site in Renton, Washington. This work was performed in accordance with our
' proposal to you dated June 22, 2004.
Geo Group Northwest, Inc., explored subsurface soil conditions at the site by excavating eight
exploratory test pits on July 7, 2004. Soils encountered in the test pits on the southern half of the
site and near the existing residence consisted of loose to medium dense cobbly and gravelly silty
SAND fills with occasional debris overlying dense to very dense fine SAND or gravelly silty
SAND (till). The fills had thicknesses ranging from 1.5 feet to 10 feet at the test pit locations.
Soils encountered in the test pits located near the north property line and at the northwest corner
' of the site consisted of loose to medium dense fine SAND and gravelly/cobbly fine SAND
overlying dense gravelly silty SAND (till) at a depth of between one and three feet below the
ground surface.
Based on the results of our study, it is our professional opinion that the site is geotechnically
suitable for the proposed development. The proposed buildings can be supported on
' conventional spread footings bearing on the dense native site soils or on compacted structural fill
placed on top of the dense native soils. The loose site soils and fills are not suitable to support
foundations due to their loose and variable condition. Based on the findings from our soil
investigation at the site, we anticipate that the dense soil under the building areas is present
between 1.5 feet and 10 feet below ground surface (bgs).
' For the proposed residential development we recommend that the site be developed in
accordance with one of the following options:
13240 NE 20th Street, Suite 12 Bellevue, Washington 98005
' Phone 425/649-8757 FAX 425/649-8758
October 4, 2004 G-1846
' Proposed Residential Development - 12905 136"Ave. SE, Renton, Washington Page ii
' 1. The fills and loose site soils on the southern portion of the site and near the existing
house should be over-excavated and replaced with compacted structural fills. The
proposed homes may be constructed to bear on compacted structural fill placed on top of
' the dense site soils. This option would require a large amount of excavation and fill
placement across the entire southern and northeastern portions of the site. Because of the
' high-density of the proposed buildings and the predictable behavior of structural fill it is
our opinion that this option, over-excavation and structural fill replacement, is the
preferable option.
2. Alternatively, all homes located in the southern and northeastern fill areas may be
Y y
' supported by small diameter pipe piles driven into the dense site soils. Both the building
foundations and the proposed concrete floors should be structurally supported on pipe
piles for the buildings located in the anticipated fill area.
' The homes to be located outside of the anticipated fill areas, at the north and northwestern
portions of the site, may be constructed to bear on the dense native site soils or on compacted
' structural fill placed on top of the native dense site soils. We anticipate that the dense soils are
present at depths ranging from 1 to 3 feet below the ground surface. Please refer to the text of the
report for more specific recommendations regarding the site development.
We appreciate this opportunity to have been of service to you on this project. We look forward
to working with you as this project progresses. Should you have any questions regarding this
report or need additional consultation, please feel free to call us.
' Sincerely,
Geo Group Northwest, Inc.
ti1NM C$
zo„4
William Chang, P.E. o �F 20114
' Principal sSI�NAL:_ G
EXPIRES: 2/19/
' Geo Group Northwest, Inc.
1
' TABLE OF CONTENTS
JOB NO. G-1846
' 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page
. 1
1.1 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Scope of Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Geologic Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
' 2.3 Field Investigation 3
. . . . . . • . . • . . • • , . . ' . . . . . • • . . . . ' . • • . . . . , . . • • • . • . . • .
2.4 Soil Conditions 3
2.5 Groundwater Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1 3.0 CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 General 4
3.2 Site Preparation and General Earthwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2.1 Temporary Excavation and Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2.2 Structural Fill . . . . . . . . . . . . . . . . . . . . . 6
. . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Spread Footing Foundations . g
3.4 Pipe Pile Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5 Slab-on-Grade Floors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.6 Footing Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.7 Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.0 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
I5.0 ADDITIONAL SERVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
' ILLUSTRATIONS
Plate 1 - Site Vicinity
Plate 2 - Existing Site Plan
Plate 3 - Proposed Site Plan
' Plate 4 - Typical Footing Drain
APPENDIX A: TEST PIT LOGS
' Geo Group Northwest, Inc.
GEOTECHNICAL ENGINEERING STUDY
PROPOSED RESIDENTIAL DEVELOPMENT
12905 136TH AVENUE SE
RENTON, WASHINGTON
' G-1846
1.0 INTRODUCTION
1.1 Project Description
P
tThe project site is located at 12905 136`h Avenue SE in Renton, Washington, as shown on Plate
1 - Vicinity Map. 136`h Avenue SE is also referred to as Bremerton Avenue NE. The project
' parcel consists of an approximately 2.4 acre lot located on the western side of 1361h Avenue SE.
We understand that the proposed development will be called Ridgeview Court. We have been
provided with a preliminary site plan for the proposed site development by Nash, Jones,
Anderson Architects. According to the site plan the development will consist of 20 new single
family residences, as shown on Plate 3 - Proposed Site Plan. We understand that the existing
residence and outbuildings at the site will be demolished. An access road and cul-de-sac
turnaround is planned for the center of the lot. Finish floor elevations for the new buildings were
not provided. Based upon our discussions with Mr. Mike Johnson of Nash Jones Anderson we
understand that structural fills may be placed over the southern portion of the site to create a
more level site. Consequently, we understand that the main floors for the proposed buildings are
' planned to be at or above the present grade. We understand that a stormwater facility such as a
detention vault is planned for the western side of the site with excavations on the order of eight
feet below existing grade.
1.2 Scope of Services
' The tasks we completed for this stud were conducted in p y general accordance with the scope of
work presented in our proposal dated June 22, 2004. The scope of work included the following:
1. Field exploration with six to eight test pits;
2. Preparation of test pit logs containing subsurface soil and groundwater observations;
3. Preparation of a written geotechnical report with the following recommendations:
' Geo Group Northwest, Inc.
October 4, 2004 G-1846
iProposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 2
' • Allowable soil bearing capacity and foundation design criteria;
• Slab-on-grade floors and capillary break;
• Excavations, including temporary cut slope recommendations;
• Grading and earthwork;
• Drainage recommendations.
The results of our subsurface investigation and our recommendations regarding the proposed
development are summarized in the following report.
2.0 SITE CONDITIONS
2.1 Site Description
We have been provided with a topographic survey for the project site by American Engineering,
Inc.. According to the survey, a single story residence is located near the northeast corner of the
site, as shown on Plate 2 - Existing Site Plan. Based upon our discussions with the current
resident at the site, we understand that the residence has a basement, although it is not apparent
from the exterior of the house. A concrete rubble rockery is located just east of the existing
residence. According to the topographic plan the rockery has a maximum height of 5.5 feet. A
shed and shop building are located near the western property line. A gravel and dirt driveway
runs roughly parallel and in close proximity to the north property line. The remainder of the site
is undeveloped and highly vegetated by blackberry bushes and small deciduous trees. Some
tlarger evergreen trees are located on the northern portion of the property.
The site has a vertical relief of approximately 20 feet with an elevation of 416 at the north
property line and 396 near the southwest corner of the site. In general the topography on the
northern half of the site consists of a flat to gentle south-facing slope. A nearly level area is
located at the base of the gentle slopes and extends over the majority of the southern portion of
the site. The level area is bordered on the east by a small west-facing slope, the embankment for
136`h Avenue SE. On the south the level area is bordered by a berm which parallels the southern
property line. At the western edge of the property the level area drops off to another level area
on the adjacent western property, approximately eight feet lower.
1 Geo Group Northwest, Inc.
October 4, 2004 G-1846
Proposed Residential Development - 12905 1361h Ave. SE, Renton, Washington Page 3
tBased upon discussions with the current site resident and Mr Cliff Williams of Vineyards
Construction, LLC we understand that fills are known to have been placed at the southern berm
location and just to the east of the existing house, behind the existing rockery.
2.2 Geologic Overview
According to the Geologic Ma of the Renton Quadrangle, King County, Washington, by
Mullineaux, dated 1965, the surficial geology in the site vicinity is mapped as Ground Moraine
Deposits (Qgt). The ground moraine deposits consist of glacial till soils which are generally
described as an over-consolidated mixture of sand, silt and gravel which was deposited during
' the Pleistocene Fraser Glaciation period about 14,000 years ago.
2.3 Field Investigation
Geo GroupNorthwest Inc. explored subsurface soil conditions at the site b excavating and
p Y g
logging eight exploratory test pits TP-1 through TP-8 on July 7, 2004. The test pits were spaced
relatively equidistant across the site, as shown on Plate 2 - Site Plan.
The test pits were excavated to depths ranging between 4 and 10.5 feet below ground surface
(bgs). Soil samples at varying depths were collected, classified and returned to our laboratory
for moisture testing. The test pits were then backfilled with the excavated site soils and tamped
into place by the backhoe bucket.
2.4 Soil Conditions
Soils encountered in the test pits on the southern half of the site and near the existing residence
' consisted of loose to medium dense cobbly and gravelly silty SAND fills with occasional debris
overlying dense to very dense fine SAND or gravelly silty SAND (till). The fills had thicknesses
t ranging from 1.5 feet to 10 feet at the test pit locations. Soils encountered in the test pits located
near the north property line and at the northwest corner of the site consisted of loose to medium
dense fine SAND and gravelly/cobbly fine SAND overlying dense gravelly silty SAND (till) at a
depth of between one and three feet below the ground surface. We interpret the gravelly silty
SAND soils to be the glacial till soils discussed in the geologic literature. The following table
summarizes the depth to dense site soils at each test pit location:
Geo Group Northwest, Inc.
October 4, 2004 G-1846
Proposed Residential Development- 12905 136" Ave. SE, Renton, Washington Page 4
Test Pit Number Project Area Depth to dense native soil
ft
TP-1 Southeast 8
TP-2 East 3.5
' TP-3 South 7
TP-4 Southwest 10
TP-5 West 4
TP-6 Northwest 3
TP-7 North 1
TP-8 Northeast 7
Copies of the Test Pit Logs are presented in Appendix A: Test Pit Logs.
2.5 Groundwater Conditions
i
No groundwater seepage was encountered in the test pits. It should be noted that groundwater
conditions may fluctuate seasonally, depending on rainfall, surface runoff and other factors.
3.0 CONCLUSIONS AND RECOMMENDATIONS
1 3.1 General
Based upon the results of our study, it is our professional opinion that the site is geotechnically
suitable for the proposed development. The proposed buildings may be supported on
conventional spread footings bearing on the dense native site soils or on compacted structural fill
placed on top of the dense native site soils. The overlying loose to medium dense site soils and
1 fills are not suitable to support foundations. Because the existing fills are non-uniform in density
and consistency their settlement cannot be accurately predicted. For this reason we recommend
that either the fill soils be over-excavated or the buildings be supported on pile foundations. The
anticipated extent of the existing fills consists of the entire southern half and a portion of the
Geo Group Northwest, Inc.
October 4, 2004 G-1846
Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 5
1 northeastern corner of the property as shown on Plate 2 - Site Plan. Based upon our subsurface
exploration the fills and loose soils in the southern and northeastern portion of the site overlie the
dense site soils at depths ranging from 1.5 to 10 feet below the ground surface.
For the proposed residential development we recommend that the site be developed in
accordance with one of the following options:
1. The fills and loose site soils on the southern portion of the site and near the existing
house should be over-excavated and replaced with compacted structural fills. The
proposed homes may be constructed to bear on compacted structural fill placed on top of
' the dense site soils. This option would require a large amount of excavation and fill
placement across the entire southern and northeastern portions of the site. Because of the
high-density of the proposed buildings and the predictable behavior of structural fill it is
our opinion that this option, over-excavation and structural fill replacement, is the
preferable option.
r2. Alternatively, all homes located in the southern and northeastern fill areas may be
supported by small diameter pipe piles driven into the dense site soils. Both the building
I foundations and the proposed concrete floors should be structurally supported on pipe
piles for the buildings located in the anticipated fill area.
1 The homes to be located outside of the anticipated fill areas, at the north and northwestern
portions of the site, may be constructed to bear on the dense native site soils or on compacted
structural fill placed on top of the native dense site soils. We anticipate that the dense soils are
present at depths ranging from 1 to 3 feet below the ground surface.
3.2 Site Preparation and General Earthwork
The building pad areas should be stripped and cleared of surface vegetation and forest duff soils.
iSilt fences should be installed around areas disturbed by construction activity to prevent
sediment-laden surface runoff from being discharged off-site. Exposed soils that are subject to
erosion should be compacted and covered with plastic sheeting.
Under option #1, the entire southern half of the site and a portion of the northeastern corner of
the site should be over-excavated to the dense native site soils. The overlying loose fills may be
IGeo Group Northwest, Inc.
October 4, 2004 G-1846
Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 6
stockpiled at the site for use as structural fill provided that the anticipated debris is removed. We
recommend that Geo Group Northwest, Inc. be retained to verify that the over-excavation has
extended to the appropriate depth to remove all loose soils and fills.
Under option #2, the building pads would be excavated to the design elevations in preparation
for pipe pile installation.
3.2.1 Temporary Excavation and Slopes
Under no circumstances should temporary excavation slopes be greater than the limits specified
P ry P g p
in local, state and national government safety regulations. Temporary cuts greater than four feet
in height should be sloped at an inclination no steeper than 1H:1V (Horizontal:Vertical) in the
loose site soils. Temporary cuts in the dense site soils may be excavated no steeper than 1H:2V
provided that no seepage is encountered. Permanent cut and fill slopes at the site should be
inclined no steeper than 2H:IV.
' Surface runoff should not be allowed to flow uncontrolled over the top of slopes into the
excavated area. During wet weather exposed cut slopes should be covered with plastic sheeting
I during construction to minimize erosion. If groundwater seepage is encountered during
construction, excavation of cut slopes should be halted and the cut slopes should be re-evaluated
by Geo Group Northwest, Inc.
' 3.2.2 Structural Fill
All fill material used to achieve design site elevations below the building areas and below non-
structurally supported slabs,parking lots, sidewalks, driveways, and patios, should meet the
' requirements for structural fill. During wet weather conditions, material to be used as structural
fill should have the following specifications:
' 1. Be free draining, granular material containing no more than five (5)percent fines (silt and
clay-size particles passing the No. 200 mesh sieve);
' 2. Be free of organic material and other deleterious substances, such as construction debris
and garbage;
t3. Have a maximum size of three (3) inches in diameter.
Geo Group Northwest, Inc.
October 4, 2004 G-1846
IProposed Residential Development - 12905 1361h Ave. SE, Renton, Washington Page 7
All fill material should be laced at or near the optimum moisture content. The i
p p optimum
' moisture content is the water content in soil that enables the soil to be compacted to the highest
dry density for a given compaction effort.
The majority of the surficial site soils will be moisture-sensitive because they consist of fine
SAND with some silt soils. The site soils should be suitable for use as structural fill as long as
they are placed near their optimum moisture content. If these soils are too wet they will be very
tdifficult to compact because of their silt content. Alternatively, an imported granular fill
material may provide more uniformity and be easier to compact to the required structural fill
specification.
If the on-site soils are to be used as engineered structural fill, it will be necessary to segregate the
topsoil and any other organic- or debris-containing soil, because such soils would be unsuitable
for use as structural fill. Excavated on-site material that is stockpiled for later use as structural
' fill should be protected from rainfall or contamination with unsuitable materials by covering it
with plastic sheeting until it is used.
Structural fill should be placed in thin horizontal lifts not exceeding ten inches in loose
thickness. Structural fill under building areas (including foundation and slab areas), should be
compacted to at least 95 percent of the maximum dry density, as determined by ASTM Test
Designation D-1557-91 (Modified Proctor).
1 Structural fill under parking lots and sidewalks should be compacted to at least 90 percent
maximum dry density, as determined by ASTM Test Designation D-1557-91 (Modified Proctor).
Fill placed within 12-inches of finish grade should meet the 95% requirement.
' We recommend that Geo Group Northwest, Inc., be retained to evaluate the suitability of
structural fill material and to monitor the compaction work during construction for quality
' assurance of the earthwork.
j3.3 Spread Footing Foundations
i
1 Geo Group Northwest, Inc.
October 4, 2004 G-1846
1 Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 8
' The proposed buildings can be supported on conventional spread footings bearing on the dense
native site soils or on compacted structural fill placed on top of the dense native site soils. Based
1 on the findings from our soil investigation at the site, we anticipate that the dense soils are
present between 1.5 feet and 10 feet below ground surface at the building locations. We
recommend that over-excavation and re-placement with structural fill occur at the southern half
of the site and northeastern corner of the site, as discussed in the site preparation section of this
report.
tIndividual spread footings may be used for supporting columns and strip footings for bearing
walls. Our recommended minimum design criteria for foundations bearing on the dense site
soils or on compacted structural fill are as follows:
- Allowable bearing pressure, including all dead and live loads
Dense native soil =2,500 psf
Compacted structural fill =2,500 psf
' - Minimum depth to bottom of perimeter footing below adjacent final exterior grade= 18
inches
- Minimum depth to bottom of interior footings below top of floor slab = 18 inches
I - Minimum width of wall footings = 16 inches
1 - Minimum lateral dimension of column footings = 24 inches
- Estimated post-construction settlement= 1/4 inch
' - Estimated post-construction differential settlement; across building width= 1/4 inch
A one-third increase in the above allowable bearing pressures can be used when considering
short-term transitory wind or seismic loads.
Lateral loads can also be resisted by friction between the foundation and the supporting
compacted fill subgrade or by passive earth pressure acting on the buried portions of the
foundations. For the latter, the foundations must be poured "neat" against the existing
Geo Group Northwest, Inc.
October 4, 2004 G-1846
1 Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 9
undisturbed soil or be backfilled with a compacted fill meeting the requirements for structural
fill. Our recommended parameters are as follows:
- Passive Pressure (Lateral Resistance)
• 350 pcf equivalent fluid weight for compacted structural fill
• 350 pcf equivalent fluid weight for native dense soil.
- Coefficient of Friction (Friction Factor)
• 0.35 for compacted structural fill
• 0.35 for native dense soil
We recommend that footing drains be placed around all perimeter footings. More specific
details of perimeter foundation drains are provided below in Section 3.6 - Footing Drains.
3.4 Pipe Pile Foundations
' As an alternative to the mass over-excavation and structural fill scheme, each of the new homes
may be supported on small diameter pipe piles, commonly referred to as pin piles. The pipe piles
' should be used to support the new buildings as well as all building slabs, such as those for the
garage floors. Small-diameter pipe piles typically consist of 2 to 6 inch diameter steel pipe
driven to the appropriate refusal criteria into the dense site soils. We estimate that dense, native
soils may be present at 3.5 to 10 feet below the existing grade in the anticipated fill areas.
Pin piles can consist of two-inch diameter, Schedule 80 steel pipe. The allowable capacity of
these piles is three tons per pile when the piles are driven to refusal by using a 90-pound
jackhammer. The refusal criterion is defined to be less than one inch of pile penetration per
' minute of continuous driving for a period of three consecutive minutes. Alternatively, 3-inch or
4-inch diameter, Schedule 40, galvanized steel pipe can be used for supporting the proposed
1 structure. The refusal criteria for these larger pile sizes are substantially different from that for
2-inch piles. Also, the equipment needed to drive these larger piles is more powerful, as these
piles require more effort to drive and can attain higher bearing capacities. Table 1 below
presents a selection of available pile hammers, pipe sizes, allowable bearing capacities, and
installation refusal criteria recommended for supporting the residence foundations.
Table 1 - Pipe Pile Design Criteria
Geo Group Northwest Inc.
October 4, 2004 G-1846
Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 10
Pipe Pipe Hammer Hammer Refusal Allowable
Diameter Specification Weight Type Criterion Cavacitv
2 inch Schedule 80 90 pound Jackhammer 60 sec/inch 3 tons
' 2 inch Schedule 80 135 pound TB100* 40 sec/inch 3 tons
3 inch Schedule 40 650 pound TB225* 16 sec/inch 6 tons
4 inch Schedule 40 850 pound TB325* 16 sec/inch 9 tons
6 inch Schedule 40 1500 pound TB625* 16 sec/inch 12 tons
* = TeledyneTNI pneumatic hammer model number; criterion can be used for other equivalent
strength hammer
' The pipe piles are usually tied into the foundation by one of the following configurations:
A. Installing a steel plate on top of the pile which is located within the continuous or column
footings.
' B. Placing bent rebar into end of piles and tying to the continuous reinforcement in the
continuous or column footings.
' Our recommended parameters for passive pressure and coefficient of friction are the same as
those noted in Section 3.3 - Spread Footing Foundations.
3.5 Slab-on-Grade Floors
' Loose forest duff should be excavated from all slab subgrade areas. Slab-on-grade floors may be
constructed on top of the medium dense to dense native site soils or on top of compacted
structural fill placed on top of the competent site soils. The slab-on-grade floors should not be
constructed on top of the loose fills at the site. If the loose site soils and fills are not over-
excavated as discussed in scheme #1, then we recommend that the building concrete floors be
structurally supported by pipe piles.
To avoid moisture build-up on the subgrade, slab-on-grade floors should be placed on a capillary
break, which is in turn placed on the prepared subgrade. The capillary break should consist of a
' Geo Group Northwest, Inc.
October 4, 2004 G-1846
' Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 11
' minimum of a six (6) inch thick layer of free-draining crushed rock or gravel containing no more
than five (5) percent finer than the No. 4 sieve. A vapor barrier, such as a 6-mil plastic
membrane, is recommended to be placed over the capillary break beneath the slab to reduce
water vapor transmission through the slab. Two to four inches of sand may be placed over the
barrier membrane for protection during construction.
3.6 Footing Drains
' We recommend that drains be installed around the perimeter of the foundation footings. The
drains should consist of a four (4) inch minimum diameter, perforated or slotted, rigid drain pipe
laid at or near the bottom of the footing with a gradient sufficient to generate flow, as
schematically illustrated in Plate 4 - Typical Footing Drain Detail. The drain line should be
bedded on, surrounded by, and covered with a free-draining rock, pea gravel, or other free-
draining granular material. The drain rock and drain line should be completely surrounded by a
geotextile filter fabric, Mirafi 140N or equivalent. Once the drains are installed, the excavation
should be backfilled with a compacted fill material. The footing drains should be tightlined to
discharge into the storm water collection system.
Under no circumstances should roof downspout drain lines be connected to the footing drainage
system. All roof downspouts must be separately tightlined to discharge into the storm water
collection system. We recommend that sufficient cleanouts be installed at strategic locations to
allow for periodic maintenance of the footing drains and downspout tightline systems.
3.7 Pavements
The adequacy of pavements is strictly related to the condition of the underlying subgrade. We
recommend that all pavement subgrades be compacted by several passes of a large vibratory
drum roller prior to placement of the crushed rock base. Before paving, we recommend that the
subgrade be proof-rolled under the supervision of the geotechnical engineer to verify that the
subgrade is firm and unyielding at the time of paving. The proof-roll may be performed by
driving a fully loaded dump truck over the subgrade areas. If loose or yielding soils are
encountered it may be necessary to over-excavate and replace with compacted structural fill in
some areas. For firm and unyielding native subgrade soils we recommend the following
minimum pavement sections for driveways:
Geo Group Northwest, Inc.
October 4, 2004 G-1846
Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 12
Class "B" Asphalt Concrete (AC) 3 inches
Crushed Rock Base (3/4-inch minus) 6 inches
Or
' Concrete Pavement 6 inches
Crushed Rock Base (3/4-inch minus) 4 inches
' In accordance with the Washington State Department of Transportation Construction Manual,
transverse cracks will develop in concrete slabs at about 15 foot intervals along the length of
slabs and a slab wider than 15 feet may crack longitudinally. To control cracking of the
concrete, contraction joints should be installed. Contraction joints are weakened planes which
collect the cracking into a controlled joint, creating a maintainable joint in the slab, and
preventing random ragged cracks which spread and require expensive maintenance. We
recommend that contraction and construction joints be connected with#5 dowel bars, 30 inches
long, 18 inches on center. The contraction joints should be placed at maximum 14 foot intervals.
' 4.0 LIMITATIONS
This report has been prepared for the specific application to this site for the exclusive use of Mr.
' Robert Wenzl of Vineyards Construction, LLC and his authorized representatives. We
recommend that this report be included in its entirety in the project contract documents for use
by the contractor.
Our findings and recommendations stated herein are based on field observations, our experience
and judgement. The recommendations are our professional opinion derived in a manner
consistent with the level of care and skill ordinarily exercised by other members of the
profession currently practicing under similar conditions in this area and within the budget
constraint. No warranty is expressed or implied. In the event the soil conditions are found to
vary during site excavation, Geo Group Northwest, Inc. should be notified and the above
1 recommendation should be re-evaluated.
5.0 ADDITIONAL SERVICES
Geo Group Northwest, Inc.
October 4, 2004 G-1846
' Proposed Residential Development - 12905 1361h Ave. SE, Renton, Washington Page 13
We recommend that Geo Group Northwest Inc. be retained to perform a general review of the
final design and specifications of the proposed development to verify that the earthwork and
foundation recommendations have been properly interpreted and implemented in the design and
in the construction documents. We also recommend that Geo Group Northwest Inc. be retained
to provide monitoring and testing services for geotechnically-related work during construction.
This is to observe compliance with the design concepts, specifications or recommendations and
to allow design changes in the event substance conditions differ from those anticipated prior to
the start of construction. We anticipate the following construction monitoring inspections may
tbe necessary:
1. Site clearing and grubbing;
2. Over-excavation and structural fill placement in the southern half and northeastern corner of
the site;
3. Verification of bearing soil conditions for foundations;
4. Structural fill placement and compaction;
1 5. Slab-on-grade preparation;
6. Pipe pile installation (if required);
7. Subsurface drainage installation;
8. Proof-rolling of pavement subgrade areas.
We appreciate this opportunity to have been of service to you on this project. We look forward
to working with you as this project progresses. Should you have any questions regarding this
report or need additional consultation, please feel free to call us.
' Geo Group Northwest, Inc.
' October 4 2004
G-1846
' Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 14
Sincerely,
Geo Group Northwest, Inc.
Adam Gaston
Staff Engineer
ti1NM C�
'0 to
soy
William Chang, P.E. �•� '�c�stE
' Principal �IDNAL
EXPIRES: 2/ �l
Geo Group Northwest, Inc.
' ILLUSTRATIONS
G-1846
' Geo Group Northwest, Inc.
MR,
yyr_ �' 'h*t -�"rr=- C'� A6-aYr'•,,; i
1 t AV SHOA 1i. HL9r1 W� N N f�tl ��
a s i•n w 3s ld 1119/1
a 3s AY s.
-I �`� � r ��'16(kL 'Cl � e � NL9►1 04
x id 111,►[
+.m 35 AV Nlbbi
35 AV �3S AV t is s Q 'o.,
I:ii t, t t- t=•- N `N .4 , r
S � E••1 00 rip
--
77
M f r y r1 1si►12SC{�s y �— - Zr �..........�L7 S C7
NY l SE Pl •.�"_.� �".-• _./
��A+i
IY, �•rr,.F p u I r - 5 �Ils!` r ;: gc�h.: gym. 1 f »I �I IV fe f, �Y and ff �i I ^Loi III wS.,3�1 AV
-tHart
(3N Ad y
35 y}}}}'' ,ice r a 4,i/ `g? '� � :aPt• ~ .-i Q
yea : i n� 1�&`i� i r�� t.kl l •.h� � - * O �.",.:� U � H
3N Yb.• ' �'
:r�r�2d^ .f�Sv s' � y r� .I I s � �' ,�* � r�• � � Q �N-1 W
! v M Q05: _ :! < s' s t.' e *v'^ i 1 f i�.,/ -..; ✓ W
"i3S E - - - ------ r- in U
rsi
( ��,le,'� , 7x � / � ; , � I � �,�� {i�"';�; ,r /��;•�°C iri►eri I` �-a-^.• N� $i Q
wi
Ye inita8& � !r a v f, z.�"'�� s,� ���s- �'� 'S�iu}z, � , �, I' {•�'�b "s �• r k is�6aI ;6 QI
f j7°!7 J n« 4 � a�'^` .�`1c k Ja'D5,: Arrhs +. 7 t '�'• r �`' ''n rr� ,��.�
F ,.5. � ir1 ksa }.fp4 t w✓�1✓ Sf r TVit%4�w� �W�'IOEW n,� i $.
' �NI' _Av l' .rJa�nb' .wv t sl;aa11 AY SC
7y .xy
W uj,_ Sy r V
uI ei � ti' Y a x x.' a' , t n914 �+ start •yin,i
�001.
f.' r Y �! K s s 1 . ............p- 4pIP. • 'c
YF 4, NI
M' dllA7(I h to a. O iI mull�'�1a21 aG
30t♦N" 1 � 1 , ?�««u ftlHnd�tu �f i
tN AV
nuvt W t w '`+ Y , 1, tnNaol Sy .Hr w r
rrb invSv Ag��, Z .. ! `'�� '.- ��bb o-�
" Al t art 1 5,. `•z '9 }p&ti }e ae 1 °
th ,A `s.;AH 3q AV % i. ",,�:A ♦ $ �.:'' '� ,:,. o? I C\j.:3S 1 „ �.��' �b I 'rlY ,. r� `7
ln," o
+tir r r? I 13s
Yq.' by/ 3 N1 tt ktrFii ^ N 1 Q ^ 1s Av G,¢ �}
',Iy` frni�xnrtmr , 1�d .. fl n �P d ..JiP .�� `RF•�'.14r t#�``'�,ta /hrt h•y;r R �ISI7I I 'tt AY x..l rfi r
-L�:yo nY MiiNiN i�' � «"lfff_
>fr-`'Fc0. cr� -_ _ G. N� =�n�.� �' 4•��1..�l ✓i!.0019 � >.
K ,s{ yy 16 l c x C L. 1 a3a—al J t5
Sri h'n S r r J� 'f' '�.r >, 3S AV 111.6- u �y
"'S�+
aN Ad Y. �oriorins a`
2 fi w )SONUWU. py S g+ ., � js AV Olin
35.. iSW r , w. vl
nv �' ', (4q^`:�': . may o. •,!b ti
1 i, !" dd1'^.1::.�
Ii
U
t .
17-d
03ddV.2N10N ,bN2N ON go
o i
� ,
3„S1�,Lt.DDN Z£'0££ VOV x
t 3d
OAIDA
<
30N HN/7 N/Y/kl ,H
ZpV � ij
Y.tot 01
03HSFi
� X
x
N �
� x
All,
01.
x
_cl £'9D o
a AMUS 3"NIS x
x
Ady)00 ' Y
01 ONO N3 9 1 x
�81
c bo 9z's\=.7 9/m
a Di 6v_ ` x3
aYd ONO Z04
_ xoddY co-03.tc,t� oN 'w4clL
:.
-w --1 1421 Yd 17VNdSY-�
-- — — -
VL
_ 3JV.!1d31 Bd/l.�
hrllL Y007 d(L ad M
d3LYM A11—r �Ot
VDV
- (uf
(dAl)
d3L3)V aw YM
� b
a
� z
a
a �
c o
y x NOTE: SITE PLAN IS ADAPTED FROM TOPOGRAPHIC PLAN BY AMERICAN ENGINEERING
?' a
SITE PLAN
o r
0
Group Northwest, ItIC. PROPOSED RESIDENTIAL DEVELOPMENT
r a 12905136111 AVENUE SE
o �eotachnk:al Fnpinaera,anobplata,8
EnvirommntalSclanticta RENTON, WASIIINGTON
SCALE ,_ 1" =40'— DATE 7/14/04 MADE—AG C1IKI) WC A JOB No. G-1846 PLATE 2
N88106'17'W— 323,52'
•
25.
01
0 20'
' ti
-0-
m
co
z
0
50+21
to w
0 ,
20'
u)
co
0
' _mac �/' 9'+
T
------ ----
83,
d:
)jw-
NOTE: SITE PLAN IS ADAPTED FROM PLAN PROVIDED BY AMERICAN ENGINEERING. INC. 10/1104.
PROPOSED SITE PLAN
Group Northwest, Inc. PROPOSED RESIDENTIAL DEVELOPMENT
Geotechnical Engineers,Geologists.& 12905 136TH AVENUE SE
Environmental Scientists RENTON,WASHINGTON
]SCALE: I"=60' DATE: 10/4/04�LILDE. AG CHKD: WC JOB NO: G-1846 PLATE 3-F
6"to12"
BACKFILL WITH COMPACTED
NAT
IVE,RELATIVELY
L
INTERMEABLE SOIL
GEOTEXTILE FILTER FABRIC,
MIRAFI 140 N OREQUIVALENT
FREE DRAINING BACKFILL FOaTlhi
CONSISTING OF WASHED
ROCK OR CRUSHED ROCK
NiND UM 4 INCH DIAMETER
PERFORATED PVC PIPE
WITH POSITIVE GRADIENT
TO DISCHARGE
NOT TO SCALE
NOTES:
' 1.) Do not replace rigid PVC pipe with flexible corrugated plastic pipe.
2.) Perforated or slotted PVC pipe should be tight jointed and laid with
perforations or slots down,with positive gradient to discharge.
3.) Do not connect roof downspout drains into the footing drain lines.
TYPICAL FOOTING DRAIN DETAIL
(! � Group Northwest, Inc. PROPOSED RESIDENTIAL DEVELOPMENT
Geotechmcal Engineers,Geobgists,s 12905 136TH AVENUE SE
Environmental Solennsts RENTON,WASHINGTON
SCALE NONE DATE 7/26/04 MADE AG CHKD WC JOB NO. G-1846 PLATE 4
APPENDIX A:
' TEST PIT LOGS
1 G-1846
Geo Group Northwest, Inc.
LEGEND OF SOIL CLASSIFICATION AND PENTRATION TEST
UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)
MAJOR DIVISION GROUP SYMBOL TYPICAL DESCRIPTION LABORATORY CLASSIFICATION CRITERIA
'
CLEAN GW WELL GRADED GRAVELS,GRAVEL-SAND Cu-(D80/010)greater than 4
GRAVELS MIXTURE,LITTLE OR NO FINES DETERMINE Cc=(D302)/(D10"D60)between 1 and 3
I PERCENTAGES OF
GRAVELS (little or no POORLY GRADED GRAVELS,AND GRAVEL- GRAVEL AND SAND
(Mora Than Half fines) GP SAND MIXTURES LITTLE OR NO FINES FROM GRAIN SIZE NOT MEETING ABOVE REQUIREMENTS
COARSE- Coarse Grains DISTRIBUTION
GRAINED SOILS Larger Than No.4 CURVE ATTERSERG LIMITS BELOW
' Sieve) DIRTY GM SILTY GRAVELS,GRAVEL-SAND-SILT MIXTURES "A"LINE
GRAVELS CONTENT OF FINES or P.I.LESS THAN 4
(with some GC CLAYEY GRAVELS,GRAVEL-SAND-CLAY
EXCEEDS 12% ATTERBERG LIMITS ABOVE
fines) MIXTURES COARSE GRAINED "A"UNE
SOILS ARE or P.I.MORE THAN 7
' CLASSIFIED AS
SANDS CLEAN SW WELL GRADED SANDS,GRAVELLY SANDS, FOLLOWS: Cu=(060/010)greater than 6
SANDS LIITLE OR NO FINES Cc=(D302)/(1310•D60)between 1 and 3
(More Than Half
Coarse Grains pitlle or no POORLY GRADED SANDS,GRAVELLY SANDS, <5%Fine Grained:
' More Than Half by SP NOT MEETING ABOVE REQUIREMENTS
Weight Larger Smaller Than No. fines) LITTLE OR NO FINES GW,GP,SW,SP
Than No.200 4 Sieve)
>12%Fine Grained: ATTERBERG LIMITS BELOW
Sieve DIRTY SM SILTY SANDS,SAND-SILT MIXTURES GM,GC,SM,SC CONTENT OF "A"LINE
SANDS with P.I.LESS THAN 4
FINES
(with some 5 to 12%Fine EXCEEDS 12% ATTERBERG LIMITS ABOVE
fines) SC CLAYEY SANDS,SAND-CLAY MIXTURES Grained:use dual "A"UNE
symbols with P.I.MORE THAN 7
SILTS Liquid Limit ML INORGANIC SILTS,ROCK FLOUR,SANDY SILTS
(Below A-Line on <50% OF SLIGHT PLASTICITY 60
Plasticity Chart, [FOR
LASTICITY CHART A-Line
FINE-GRAINED Negligible Liquid Limit INORGANIC SILTS,MICACEOUS OR SOIL PASSING
SOILS Organic) >50gt MH DIATOMACEOUS,FINE SANDY OR SILTY SOIL NO.40 SIEVE
CH or OH
Liquid Limit INORGANIC CLAYS OF LOW PLASTICITY, x
CLAYS 40
(Above AYS on <30% CL GRAVELLY,SANDY,OR SILTY CLAYS,CLEAN Z
CLAYS
Plasticity Chart, } 30
Negligible Liquid Limit INORGANIC CLAYS OF HIGH PLASTICITY,FAT ~
Organic) >50% CH CLAYS IV— Z0 CL or OL
More Than Half by
Weight Smaller OL Liquid Limit ORGANIC SILTS AND ORGANIC SILTY CLAYS OF 0. MH or OH
Than No.200 ORGANIC SILTS& <50% LOW PLASTICITY 10
Sieve CLAYS 7 =Z7 OL M
(Below A Line on q
Placdcfly Chart) Liquid
i�%tt i iT
OH ORGANIC CLAYS OF HIGH PLASTICITY 0
D 30 2A 30 40 60 70 80 90 100 110
LIQUID LIMIT(%)
HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS
SOIL PARTICLE SIZE
GENERAL GUIDANCE OF SOIL ENGINEERING PROPERTIES FROM STANDARD PENETRATION TEST(SPT)
U.S.STANDARD SIEVE
' FRACTION Passing Retained SANDY SOILS SILTY&CLAYEY SOILS
Sieve Size Sieve Size Blow Relative Friction Blow Unconfined
(mm) (mm) Counts Density Angle Description Counts Strength Description
SILT I CLAY #200 0.075 N % m,degree N qu,tsf
SAND 0-4 0-15 Very Loose <2 <0.25 Very soft
FINE #40 0.425 #200 0.075 4-10 15-35 26-30 Loose 2-4 0,25-0.50 Soft
' MEDIUM #10 2 #40 0.425 10-30 35-85 28-35 Medium Dense 4-8 0.50-1.00 Medium Stiff
COARSE #4 1 4.75 #10 2 30-50 85-85 35-42 Dense 8-15 1.00-2.00 Stiff
GRAVEL >50 85-100 38-46 Very Dense 15-30 2.00-4.00 Very Stiff
FINE 19 #4 4.75 >30 >4.00 Hard
COARSE 76 19
COBBLES 78 mm to 203 mm Ad
Group Northwest, Inc.
BOULDERS >203 mm
Geotechnical Engineers,Geologists,&
ROCK >78 mm Environmental Scientists
' FRAGMENTS 13240 NE 20th Street,Suite 12 Bellevue,WA 98005
ROCK
>0.76 cubic meter in volume Phone(425)649-8757 Fax(425)649-8758 PLATE Al
1 TEST PIT NO. TP-1
LOGGED BY AG TEST PIT DATE: 7n104 GROUND ELEV. 404(+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
SM Forest Duff and moss(6-inches) S1 7.4
----- --------------------------------
-------------------
1 SM Brown gravelly/cobbly silty SAND,dry,medium dense(FILL)
est: 10%cobbles SZ 7.8
plastic sheeting and aluminum cans debris S3 7.6
5 SM dark brown,moist L
S4 9.7
----- plastic sheeting debris
--- ------------------------------------------------- -
SP Tan fine SAND with some silt,moist,dense I S5 8.9 NATIVE
10 grades to some medium grained SAND w/gravel,very dense 9'bgs
Sb 8.2
Total depth of test pit= 10 feet
No groundwater seepage
15
1 TEST PIT NO. TP-2
LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 400(+/-)
DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
Forest Duff(8-inches)
SP Brown fine SAND with some silt,moist,loose Probe 12-16"
_ -----__ S2 8.2
SP Gray fine SAND with some silt,moist,dense at 3.5 feet bgs
5 Probe 1-2"
SP moist to wet
S3 23.1
Total depth of test pit=7 feet
No groundwater seepage
1 10
1
15
TEST PIT LOGS
' = PROPOSED RESIDENTIAL DEVELOPMENT
Group Northwest, Inc. 12905 136TH AVENUE SE
Geotechnical Engineers,Geologists,& RENTON,WASHINGTON
Environmental Scientists
JOB NO. G-1846 DATE 7/7/04 PLATE A2
' TEST PIT NO. TP-3
LOGGED BY AG TEST PIT DATE: 7/7/04 GROUND ELEV. 400 (+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
SM Brown gravelly/cobbly silty SAND with debris,moist,medium
' dense(FILL) a S1 9.8
brick debris
5 buried log-24"diameter and brick debris S2 14.0 FILL
SM Dark gray silty SAND with some gravel,moist to wet,medium dense j S3 15.3
--- ----- -------------------------.---------------------------
SP Brown fine SAID with some gravels,moistdense 14.7 NATIVE
Total depth of test pit=7.5 feet
' 10 No groundwater seepage
' 15
TEST PIT NO. TP-4
LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 400 (+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
' SM Brown gravelly/cobbly silty SAND with plastic debris,moist, Sl 8.2
medium dense(FILL)
with re-bar debris
S2 11.0
with a boulder at Y bgs
5 FILL
SM with pipe debris S3 12.8
with significant amount plastic,asphalt,bicycle and tire debris
10 ----- ----------------------------------------------------
Sp Brown fine SAND with some silt,moist,dense S4 6.8 NATIVE
Total depth of test pit= 10.5 feet
No groundwater seepage
15
TEST PIT LOGS
' PROPOSED RESIDENTIAL DEVELOPMENT
Group Northwest, Inc. 12905 136TH AVENUE SE
Geotechnical Engineers,Geologists,& RENTON, WASHINGTON
' Env iro n nne n ta I Soientsts
JOB NO. G-1846 DATE 7/9/04 PLATE A3
' TEST PIT NO. TP-5
LOGGED BY AG TEST PIT DATE: 7/7/04 GROUND ELEV. 402 (+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
SM Brown silty SAND with some cobbles and gravel,dry,med. dense FILL
--- ---- --------------------------------------
- --------------
SP Brown gravelly fine SAND,dry,med. dense to dense S 1 4-3
NATIVE
dense I S2 4.6
5
SP Brown medium grained gravelly SAND,dry,very dense
S3 3.3
1 Total depth of test pit=7 feet
No groundwater seepage
10
15
' TEST PIT NO. TP-6
LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 407 (+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
' SP/ Brown fine SAND with some silt and gravel,loose to medium dense
S 1 12.9
SM
--- ---- ---------------------------------------------------- S2 10.2
SM Tan gravelly silty SAND,moist,dense(TILL),some cementation
5
Total depth of test pit=4.5 feet
' No groundwater seepage
10
15
_ TEST PIT LOGS
A` PROPOSED RESIDENTIAL DEVELOPMENT
(! Group Northwest, Inc, 12905136THAVENUE SE
1
Geotechnical Engineers,Geologists,& RENTON,WASHINGTON Environmental Scientists
JOB NO. G-1846 DATE 7/9/04 PLATE A4
' TEST PIT NO. TP-7
LOGGED BY AG TEST PIT DATE. 7/7/04 GROUND ELEV. 410 (+/-)
DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
SP/ Brown gravelly/cobbly fine SAND with some silt;dry,dense at 1'
' SM bgs. S 1 3.9
--- ----- ----------------------------------------------------
SM Tan gravelly silty SAND,moist,cemented,very dense(TILL) I S2 7.6
9 Total depth of test pit=4 feet
No groundwater seepage
' 10
15
' TEST PIT NO. TP-8
LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 408 (+/-)
' DEPTH SAMPLE Water OTHER TESTS/
ft. USCS SOIL DESCRIPTION No. % COMMENTS
SP/ Brown gravelly fine SAND with some silt,dry, loose
' SM S l 3.9 probe 2'
with glass and tire debris,caving,very loose FILL
5
--- ----- ----------------------------------------------------
SM Gravelly silty SAND moist,dense at 7'bgs S2 7.6 NATIVE
Total depth of test pit=8 feet
10 No groundwater seepage
House occupant indicates fills placed here in 1960
15
r
TEST PIT LOGS
1 PROPOSED RESIDENTIAL DEVELOPMENT
# Group Northwest, Inc. 12905 136TH AVENUE SE
' Geotechnical Engineers,Geologists,& RENTON,WASHLNGTON
Ew ironmental ScienCsts
JOB NO. G-1846 I DATE 7/9/04 1 PLATE A5
A
A
W
ST 1 .0/
ST 1.0 LA0.8 LA0.9 LA 1.0 LA1.2
ST 1 .1 - ` UISN COUNTY
suoNo
i fr.,-�. r -'soTwEt4 w000lNvly:i
y \ H KING COUNTY
RESP jr� �......_...
f __ PEOYCNO
� RE MOND, �
C% I
' I CI(RNAT
Cl
+� GP-YOE __ •'_7
s KUL
E7LoC f / ; ELLEVUE
847
r EAUJ< +1 �tA1cE�
MERCER [ ONpNANELAND
Ifi b - FALL
1.4
If
i
SEATTLE�.� PRESTO d�snocuAlule',
ak r 1 `-1 f.l-r PdM L'ti�i
I mEsgAaU�
—,Vr P
UPPER ,
PPESTON ` N1
L_ TO ,1
auRIEN.I i ru ILA�
0
1 Q ATA - � oRuoNr
J`I
�aaa CY S TAC-1 %7 I. _ I' FERRIaron
i -
LANDSBURG
CID
YA.Aon
stool C�
V l 1
.......n_--+-_.. v— _....—..
hid
[. / / �� unosauPo
AUEURN' -^ Dll_"` �YL K
,IAM ND
ST 1.1 EJEPAL WAY i
j PACIn 1KING COUNTY
PIERCE COUNTY
ST 1.0
.a
iNuueuv�,
ST 1 .0/ --_.1
Rainfall Regions and LA 0.8
Regional Scale Factors LA 0.9
LA 1.2
Incorporated Area LA 1.0
' ...cam River/Lake
Major Road
' SECTION 5.3 DETENTION FACILITIES
Riser Overflow
The nomograph in Figure 5.33.4.H can be used to determine the head (in feet) above a riser of given
diameter and for a given flow (usually the 100-year peak flow for developed conditions).
FIGURE 5._.4.H RISER INFLOW CURVES
100 -----------
72 54 48
42
i
I j i 1 i i i I I i i
36
i
33 I t
30
I 27 I
' 24
1010
21 Ic
1
� � )
0 18 w ;
0 i
I r
a� 10 Loo�
I I 15 w l
i t I I I I
12
i t
� IAll, I I I i I
i .
1040
I
� li
1
c
O.S 1 0
0.1 HEAD IN measulred from crest of riser)
Q, j,=9.739 DH..2
Q o,itiee=3.782 D 2H 1/2
Q in cfs, D and H in feet
Slope change occurs at weir-orifice transition
' 9/l/98 1998 Surface Water Design Manual
5-50
PIPE SIZING CHART, 100-YEAR CONVEYANCE DESIGN, FORBES CREEK 11, CHAFFEY HOMES AEC#0448, 4-8-05
BY: RWS
' PERV TRIB I C.
PEAK Q AREA DWNSTR UPSTRM
MP PERV IMPERV AVG Tc ACTUAL Q V PIPE DWNSTR UPSTRM PIPE PIPE PIPE HYDRAULIC Q FULL
SYSTEM DWNSTRM UPSTRM AREA AREA TO RAINFALL DESIGN OF DWNSTR UPSTRM INVERT INVERT Q-FULL V Q
AREA TO C. C. W/ Tc Ar,00 Bf,� P,00 If,� DESIGN AT DESIGN NO.PER RIM ELEV RIM ELEV LENGTH SLOPE SIZE "N" RADIUS "R" Q
NO. CB CB TO CB CB INTENSITY SYSTEM PIPE CB CB ELEV ELEV (CFS) FULL RATIO
(AC) CB(AC) (AC) TO CB TO CB TO CB VFULL USED „)f„ STRUCTURE (CFS) (SF) (FPS) KCBW (FT) (FT) (FT) (FT) (FT) (FT/FT) (IN) (FT) DESIGN
1 VAULT CB2 0.00 0.06 0.06 0.25 0.90 0.90 8.6 8.6 2.61 0.63 3.82 0.67 2.58 0.14 4.98 1.77 2.82 VAULT CB2 N1 402.20 394.50 402.85 1 397.42 51 0.0573 18.00 0.014 0.375 14.0 7.9 2.8 0.16
1 CB2 CB3 0.00 0.00 1 0.00 0.25 0.90 #DIV/0! 8.5 8.5 2.61 0.63 3.82 0.68 2.60 1 0.00 4.27 1.77 2.42 C132 CB3 N2 402.85 397.42 403.27 398.50 51 0.0212 18.00 0.014 0.375 8.5 4.8 2.0 0.38
1 CB3 CB4 0.00 0.03 0.03 0.25 0.90 0.90 8.3 8.3 2.61 0.63 1 3.82 0.69 2.63 1 0.07 3.10 0.79 3.95 CB3 CB4 N3 403.27 1 399.00 404.51 400.20 54 0.0222 12.00 0.014 0.250 3.4 4.3 1 1.1 1.13
1 CB4 CB5 0.13 0.13 0.26 0.25 0.90 0.58 8.1 8.1 2.61 0.63 3.82 0.70 2.68 0.40 1.45 0.79 1.85 CB4 CB5 I N4 404.51 400.20 406.46 401.66 65 0.0225 12.00 0.014 0.250 3.4 4.3 2.3 0.38
1 CB5 CB6 0.01 0.03 0.04 0.25 0.90 0.74 7.8 7.8 2.61 0.63 3.82 0,71 2.73 0.08 1.05 0.79 1.34 CB5 C136 N5 406.46 401.66 408.59 401.84 36 0.0050 12.00 0.014 0.250 1.6 2.0 1.5 0.30
1 CB6 CB7 0.01 0.02 0.03 0.25 0.90 0.68 7.5 7.5 2.61 0.63 3.82 0.73 2.80 0.06 0.81 0.79 1.03 CB6 C137 N6 408.59 401.84 408.83 402,01 34 0.0050 12.00 0.014 0.250 1.6 2.0 2.0 0.08
1 CB7 CB8 0.04 0.09 0.13 0.25 0.90 0.70 7.2 7.2 2.61 0.63 3.82 0.75 2.86 0.26 0.75 0.79 0.96 C137 CB8 N7 408.83 402.01 404.89 402.59 116 0.0050 12.00 0.014 0.250 1.6 2.0 2.1 0.53
1 CB8 CB9 0.09 0.15 0.24 0.25 0.90 0.66 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.49 0.49 0.79 0.63 CB8 CB9 N8 404.89 402.59 404.89 402.89 1 31 0.0097 12.00 0.014 0.250 2.2 2.8 4.5 0.00
2 VAULT CB1 0.26 0.27 1 0.53 0.25 1 0.90 0.58 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.97 0.97 0.79 1.24 VAULT CB1 N1 403.25 395.00 404.18 399.28 29 0.1476 1 12.00 0.014 0.250 8.7 11A 9.0 0.00
3 CB3 CB14 0.14 0.17 0.31 0.25 0.90 0.61 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.59 0.59 0.79 0.75 C133 C814 IN 403.27 399.00 403.64 399.64 39 0.0164 12.00 0.014 0.250 2.9 3.7 4.9 0.00
4 CB3 CB13 0.14 0.17 0.31 0.25 0.90 0.61 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.59 0.59 0.79 0.75 C63 CB13 N1 403.27 399.00 403.69 399.69 69 0.0100 12.00 0.014 0.250 2.3 2.9 3.9 0.00
=am WPM am
6 CB4 CB15 0.00 0.43 0.43 0.25 0.90 0.90 6.5 6.5 2.61 0.63 3.82 0.80 3.07 1.19 1.46 0.79 1.86 CB4 CB15 N1 404.51 400.20 404.51 400.51 31 0.0100 12.00 0.014 0.250 2.3 2.9 1.6 4.37
6 CB15 CB16 0.06 0.08 0.14 0.25 0.90 0.62 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.27 0.27 0.79 0.35 C815 CB16 N2 404.51 400.51 405.25 401.25 11 0.0673 12.00 0.014 0.250 5.9 7.5 21.6 0.00
7 CB6 CB10 0.00 0.04 0.04 0.25 0.90 0.90 6.8 6.8 2.61 0.63 3.82 0.78 2.99 0.11 0.16 0.79 0.21 CB6 CB10 N1 408.59 401.84 409.50 405.19 130 0.0258 12.00 0.014 0.250 3.6 4.6 22.2 1.91
7 CB10 CB11 0.00 0.02 0.02 0.25 0.90 0.90 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.06 0.06 0.79 0.07 CB10 CBI N2 409.50 405.19 409.76 405.37 18 0.0100 12.00 0.014 0.250 2.3 2.9 40.2 0.00
8 CB2 CB12 0,00 0,20 1 0.20 0,25 0.90 0,90 6.3 6.3 2.61 0.63 1 3.82 0.82 3.13 1 0.56 0.56 0.79 0.72 CB2 C612 Ni 402.20 395.00 404.18 399.28 1 29 0.1476 12.00 1 0.0141 0.250 1 8.7 1 11.1 15.5 0.00
Pery Imp
Total 0.88 1.73
0.88 1.73 2,61
Total Area= 2,61
i
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sysl.bwp
' Surcharge condition at intermediate junctions
Tailwater Elevation:402 .2 feet
' Discharge Range:4. 96 to 4.98 Step of 0.01 [cfs]
Overflow Elevation:404 . 89 feet
Weir:NONE
Upstream Velocity:l. feet/sec
' CB Z
PIPE NO. 1: 51 LF - 1811CP @ 5 .73% OUTLET: 394 .50 INLET: 397 .42 INTYP: 5
JUNC NO. 1: OVERFLOW-EL: 402 . 85 BEND: 0 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.16
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
' 4.96 4 .99 402 .41 * 0 .012 0 .86 0.44 7.70 7.70 4 .88 4.99 1.16
4.97 4 .98 402 .40 * 0.012 0.86 0.44 7.70 7.70 4. 88 4.98 1.17
4.98 4.98 402 .40 * 0 .012 0.86 0.44 7.70 7.70 4.88 4.98 1.17
C-g 3
PIPE NO. 2 : 51 LF - 18"CP @ 2 .12% OUTLET: 397.42 INLET: 398 .50 INTYP: 5
JUNC NO. 2 : OVERFLOW-EL: 403 .27 BEND: 90 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.38
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
4 .28 4.26 412 .76 * 0.012 0. 80 0.52 4.99 4.99 3 .98 4.26 1.29
4 .28 4 .26 402 .76 * 0 .012 0.80 0.53 4 .98 4.98 3 .98 4.26 1.30
4.29 4.26 402 .76 * 0.012 0 .80 0.53 4.98 4 .98 3 .98 4.26 1.30
CA y
PIPE N0. 3 : 54 LF - 1211CP @ 2 .22% OUTLET: 399.00 INLET: 400.20 INTYP: 5
JUNC NO. 3 : OVERFLOW-EL: 404.51 BEND: 0 DEG DIA/WIDTH: 2 .0 Q-RATIO: 1.13
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
3 .10 3 .25 403 .45 * 0.012 0 .76 0.53 3 .76 3 .76 2 .91 3 .25 1.25
3 .10 3 .25 403 .45 * 0.012 0 .76 0 .53 3 .76 3 .76 2 .91 3 .25 1.25
3 .11 3 .25 403 .45 * 0.012 0.76 0 .53 3 .76 3 .76 2 .91 3 .25 1.26
PIPE N0. 4 : 65 LF - 1211CP @ 2 .25% OUTLET: 400 .20 INLET: 401.66 INTYP: 5
JUNC NO. 4 : OVERFLOW-EL: 406.46 BEND: 90 DEG DIA/WIDTH: 4 .0 Q-RATIO: 0 .38
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
1.45 1.99 403 .65 * 0 .012 0 .52 0.35 3 .25 3 .25 1.89 1.99 0.75
1.46 1.98 403 .64 * 0.012 0.52 0 .35 3 .25 3 .25 1.88 1.98 0.75
1.46 1.98 403 .64 * 0.012 0.52 0.35 3 .25 3 .25 1.89 1.98 0.75
i
' PIPE NO. 5 : 36 LF - 12"CP Q 0.50% OUTLET: 401.66 INLET: 401.84 INTYP: 5
JUNC NO. 5 : OVERFLOW-EL: 408.59 BEND: 90 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.30
LQ L
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
1.05 1. 89 403 .73 * 0 .012 0.44 0.44 1.99 1.99 1.84 1.89 0.62
1.06 1. 88 403 .72 * 0 .012 0.44 0.44 1.98 1.98 1. 83 1.88 0.62
1.06 1.88 403 .72 * 0.012 0.44 0.44 1.98 1.98 1. 83 1.88 0.62
cb 7
PIPE NO. 6: 34 LF - 12"CP Q 0.50% OUTLET: 401.84 INLET: 402 .01 INTYP: 5
JUNC NO. 6: OVERFLOW-EL: 408 . 83 BEND: 0 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.08
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.81 1.75 403 .76 * 0.012 0.38 0.38 1.89 1. 89 1.74 1.75 0.51
0.81 1.73 403 .74 * 0.012 0.38 0.38 1.88 1.88 1.72 1.73 0.51
0.81 1.74 403 .75 * 0 .012 0.38 0.38 1.88 1.88 1.73 1.74 0.51
co 8
PIPE NO. 7 : 116 LF - 12"CP Q 0.50% OUTLET: 402 .01 INLET: 402 .59 INTYP: 5
JUNC NO. 7: OVERFLOW-EL: 404 . 89 BEND: 90 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.53
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.75 1.25 403 . 84 * 0.012 0.37 0.36 1.75 1.75 1.22 1.25 0.51
0.75 1.22 403 . 81 * 0.012 0.37 0.36 1.73 1.73 1.20 1.22 0.51
' 0.75 1.23 403 . 82 * 0.012 0.37 0.36 1.74 1.74 1.20 1.23 0.51
L Q
Q t
PIPE NO. 8 : 31 LF - 12"CP Q 0.97% OUTLET: 402. .59 INLET: 402 .89 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.49 0.95 403 . 84 * 0.012 0 .30 0.25 1.25 1.25 0.95 0.94 0.38
0.49 0.93 403 .82 * 0.012 0.30 0.25 1.22 1.22 0.93 0.92 0.38
0.49 0.94 403 .83 * 0.012 0.30 0.25 1.23 1.23 0.94 0.93 0.38
' Sys rz-,n
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys2 .bwp
tSurcharge condition at intermediate junctions
Tailwater Elevation:402.2 feet
Discharge Range:0. 95 to 0.97 Step of 0 .01 (cfs]
Overflow Elevation:404.18 feet
Weir:NONE
Upstream Velocity:l. feet/sec
PIPE NO. 1: 29 LF - 1211CP @ 14.76% OUTLET: 395.00 INLET: 399.28 INTYP: 5
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.95 2 .96 402.24 * 0.012 0.41 0.18 7.20 7.20 2 .94 2.96 0.49
0.96 2 .96 402.24 * 0.012 0.42 0.18 7.20 7.20 2.94 2.96 0.49
0.97 2 .96 402.24 * 0.012 0.42 0.18 7.20 7.20 2.94 2.96 0 .49
0.98 2 .96 402.24 * 0.012 0.42 0.18 7.20 7.20 2 .94 2 .96 0.50
- vt-T
S�sa
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys3 .bwp
tSurcharge condition at intermediate junctions
Tailwater Elevation:402 .76 feet
1 Discharge Range:0.57 to 0.59 Step of 0.01 [cfs]
Overflow Elevation:403 .64 feet
Weir:NONE
Upstream Velocity:l. feet/sec
PIPE NO. 1: 39 LF - 1211CP @ 1.64% OUTLET: 399.00 INLET: 399.64 INTYP: 5
' Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
0.57 3 .13 402 .77 * 0.012 0.32 0.23 3 .76 3 .76 3 .13 3.13 0.41
' 0.58 3 .13 402 .77 * 0.012 0.32 0.24 3.76 3 .76 3.13 3.13 0 .41
0.59 3 .13 402 .77 * 0.012 0.32 0.24 3.76 3 .76 3'.13 3 .13 0.42
I
sYs� � y
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys4 .bwp
' Surcharge condition at intermediate junctions
Tailwater Elevation:402 .76 feet
Discharge Range:0.57 to 0.59 Step of 0.01 [cfs]
Overflow Elevation:403 .69 feet
Weir:NONE
Upstream Velocity:l. feet/sec
ce 13
PIPE NO. 1: 69 LF - 1211CP @ 1.00% OUTLET: 399.00 INLET: 399.69 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.57 3 .09 402 .78 * 0.012 0.32 0.26 3 .76 3 .76 3.09 3.09 0.41
0.58 3 .09 402 .78 * 0.012 0.32 0.27 3 .76 3 .76 3 .09 3 .08 0.42
0.59 3 .09 402 .78 * 0.012 0.32 0.27 3 .76 3 .76 3.09 3 .08 0.42
r
S�rsT�M�
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys5.bwp
' Surcharge condition at intermediate junctions
Tailwater Elevation:403 .45 feet
Discharge Range:0 .1 to 0 .11 Step of 0 .01 [cfs]
Overflow Elevation:405 .25 feet
Weir:NONE
Upstream Velocity:l. feet/sec
jc a tZ
PIPE NO. 1: 11 LF - 12"CP @ 9.55% OUTLET: 400.20 INLET: 401.25 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.10 2 .21 403 .46 * 0 .012 0.13 0.07 3 .25 3 .25 2 .21 2.19 0.11
0.11 2 .20 403 .45 * 0 .012 0.14 0 .07 3 .25 3 .25 2 .20 2.19 0.12
L
1
1
SyS�M
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys6.bwp
Surcharge condition at intermediate junctions
Tailwater Elevation:403 .45 feet
Discharge Range:1.44 to 1.46 Step of 0 .01 [cfs]
Overflow Elevation:405 .25 feet
Weir:NONE
Upstream Velocity:l. feet/sec
GBI�
PIPE NO. 1: 31 LF - 1211CP @ 1.00% OUTLET: 400.20 INLET: 400 .51 INTYP: 5
( JUNC 110. 1: OVERFLOW-EL: 404 .51 BEND: 90 DEG DIA/WIDTH: 2 .0 Q-RATIO: 4.37
Q(CFS) HW(FT) HW ELEV. * N FAC DC DN TW DO DE HWO HWI
*******************************************************************************
1.44 3 .07 403 .58 * 0.012 0.51 0 .43 3 .25 3 .25 2 .99 3 .07 0.74
1.45 3 .07 403 .58 * 0 .012 0.52 0 .43 3 .25 3 .25 2 .98 3.07 0.74
1.46 3 .07 403.58 * 0 . 012 0 .52 0.43 3 .25 3 .25 2 .98 3 .07 0.75
C� lG
PIPE NO. 2 : 11 LF - 1211CP @ 6.73% OUTLET: 400.51 INLET: 401.25 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.27 2 .34 403 .59 * 0.012 0.22 0. 12 3 .07 3 .07 2 .34 2 .33 0.24
0.27 2 .33 403 .58 * 0.012 0 .22 0.12 3 .07 3 .07 2 .33 2.31 0.24
0 .27 2 .33 403.58 * 0 .012 0 .22 0.12 3 .07 3 .07 2 .33 2 .32 0.24
L
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys7.bwp
Surcharge condition at intermediate junctions
Tailwater Elevation:403 .73 feet
' Discharge Range:0 . 14 to 0.16 Step of 0 .01 (cfs]
Overflow Elevation:409.76 feet
Weir:NONE
Upstream Velocity:l. feet/sec
! co /0
PIPE NO. 1: 130 LF - 1211CP @ 2 .58%- OUTLET: 401.84 INLET: 405.19 INTYP: 5
JUNC NO. 1: OVERFLOW-EL: 408 .59 BEND: 90 DEG DIA/WIDTH: 2 .0 Q-RATIO: 1.91
Q(CFS) HW(FT) HW ELEV. * N FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.14 0 .19 405.38 * 0.012 0.16 0.11 1.89 1.89 0.16 ***** 0.19
0.15 0.20 405.39 * 0.012 0.16 0.11 1.89 1.89 0 .16 ***** 0.20
0.16 0.21 405.40 * 0.012 0.17 0.12 1.89 1.89 0.17 ***** 0.21
! « J/
PIPE NO. 2 : 18 LF - 1211CP @ 1.00�; OUTLET: 405.19 INLET: 405.37 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.05 0 .10 405 .47 * 0 .012 0.09 0.08 0 .19 0 .19 0.09 ***** 0.10
0.05 0.10 405.47 * 0.012 0.10 0 .09 0.20 0.20 0.10 ***** 0.10
' 0.05 0 . 11 405 .48 * 0.012 0 .10 0 .09 0.21 0.21 0.10 ***** 0.11
1
t
S�Sg
BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:sys8 .bwp
Surcharge condition at intermediate junctions
Tailwater Elevation:402 .4 feet
Discharge Range:0.54 to 0.56 Step of 0.01 [cfs]
Overflow Elevation:402 .45 feet
Weir:NONE
Upstream Velocity:l. feet/sec
PIPE NO. 1: 24 LF - 1211CP @ 2 .00% OUTLET: 397.92 INLET: 398.40 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.54 4 .01 402 .41 * 0.012 0.31 0.22 4.48 4.48 4 .01 4.01 0.39
0.55 4 .00 402 .40 * 0.012 0.31 0.22 4.48 4 .48 4 .00 4.00 0.40
0.56 4.01 402 .41 * 0.012 0.32 0.22 4.48 4 .48 4'01 4.00 0.40
1
W
A
W
' APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY NIAIIvTAINED DRAINAGE FACILITIES
NO. 3- CLOSED DETENTION SYSTEMS (PIPES/TANKS)
rMaintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Performed
Storage Area Plugged Air Vents One-half of the cross section of a vent is blocked at Vents free of debris and
any point with debris and sediment sediment
Debris and Accumulated sediment depth exceeds 10%of the All sediment and debris
Sediment diameter of the storage area for'h length of storage removed from storage area.
vault or any point depth exceeds 15%of diameter.
Example:72-inch storage tank would require cleaning
when sediment reaches depth of 7 inches for more
than Yz length of tank.
Joints Between Any crack allowing material to be transported into All joint between tank/pipe
Tank/Pipe Section facility sections are sealed
Tank Pipe Bent Any part of tank/pipe is bent out of shape more than Tank/pipe repaired or replaced
Out of Shape 10%of its design shape to design.
Manhole Cover Not in Place Cover is missing or only partially in place.Any open Manhole is closed.
manhole requires maintenance. 11
Locking Mechanism cannot be opened by one maintenance Mechanism opens with proper
Mechanism Not person with proper tools.Bolts into frame have less tools.
Working than'/z inch of thread(may not apply to self-locking
lids.)
Cover Difficult to One maintenance person cannot remove lid after Cover can be removed and
Remove applying 80lbs of lift. Intent is to keep cover from reinstalled by one maintenance
sealing off access to maintenance. person.
Ladder Rungs King County Safety Office and/or maintenance person Ladder meets design standards
Unsafe judges that ladder is unsafe due to missing rungs, allows maintenance person safe
' misalignment, rust,or cracks. access.
Catch Basins See"Catch Basins"Standards No.5 See"Catch Basins"Standards
No.5
i
1
1
1
t
1
1
1
1998 Surface Water Design Manual 9/1/98
A-3
APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAI.NED DRAINAGE FACILITIES
NO. 4- CONTROL STRUCTUREIFLOW RESTRICTOR
Maintenance Defect Condition When Maintenance is Needed Results Expected When
Component Maintenance is Performed
General Trash and Debris Distance between debris build-up and bottom of All trash and debris removed.
(Includes Sediment) orifice plate is less than 1-1/2 feet
Structural Damage Structure is not securely attached to manhole wall Structure securely attached to
' and outlet pipe structure should support at least wail and outlet pipe.
1,000 Ibs of up or down pressure.
Structure is not in upright position(allow up to Structure in correct position.
10%from plumb).
Connections to outlet pipe are not watertight and Connections to outlet pipe are
show signs of rust. water tight;structure repaired or
replaced and works as
designed.
Any holes—other than designed holes—in the Structure has no holes other
structure. than designed holes.
Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as
designed.
Gate cannot be moved up and down by one Gate moves up and down easily
maintenance person. and is watertight.
Chain leading to gate is missing or damaged. Chain is in place and works as
designed.
Gate is rusted over 50%of its surface area. Gate is repaired or replaced to
meet design standards..
Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and works as
missing,out of place,or bent orifice plate. designed.
' Obstructions Any trash,debris,sediment,or vegetation Plate is free of all obstructions
blocking the plate. and works as designed.
Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions
' potential of blocking)the overflow pipe. and works as designed.
Manhole See"Closed Detention Systems"Standards No.3 See"Closed Detention Systems'
Standards No.3
Catch Basin See"Catch Basins"Standards No.5 See'Catch Basins"Standards
No.5
9/1/98 1998 Surface Water Design Manual
A-4
' APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
NO. 5 - CATCH BASINS
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is performed
General Trash&Debris Trasn or aeons of more than 1/2 cubic foot which is No Trash or debris located
(includes Sediment) located immediately in front of the catch basin immediately in front of catch
opening or is blocking capacity of the basin by basin opening.
more than 10%
I
Trash or debris(in the basin)that exceeds 1/3 the No trash or debris in the catch
' depth from the bottom of basin to invert the lowest basin.
pipe into or out of the basin.
Trash or debris in any inlet or outlet pipe blocking Inlet and outlet pipes free of
more than 1/3 of its height. trash or debris.
Dead animals or vegetation that could generate No dead animals or vegetation
odors that could cause complaints or dangerous present within the catch basin.
gases(e.g.,methane).
Deposits of garbage exceeding 1 cubic foot in No condition present which
volume would attract or support the
breeding of insects or rodents.
Structure Damage to Comer of frame extends more than 3/4 inch past Frame is even with curb.
Frame and/or Top Slab curb face into the street(If applicable).
Top slab has holes larger than 2 square inches or Top slab is free of holes and
cracks wider than 1/4 inch(intent is to make sure cracks.
all material is running into basin).
Frame not sitting flush on top slab,i.e.,separation Frame is sitting flush on top
of more than 3/4 inch of the frame from the top slab.
slab.
Cracks in Basin Wails/ Cracks wider than 1/2 inch and longer than 3 feet, Basin replaced or repaired to
Bottom any evidence of soil particles entering catch basin design standards.
through cracks,or maintenance person judges that
structure is unsound.
Cracks wider than 1,'2 inch and longer than 1 foot No cracks more than 1/4 inch
at the joint of any inlet/outlet pipe or any evidence wide at the joint of inlet/outlet
of soil particles entering catch basin through pipe.
cracks.
Sediment/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to
Misalignment more than 2 inches out of alignment. design standards.
1998 Surface Water Design Manual 9/1/9S
A-5
' APPENDIX A STANDARDS FOR PRIVATELY MAIN7AINED DRAINAGE FACILITIES
NO. 5- CATCH BASINS (CONTINUED)
( Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is performed
=ire Hazard Presence of chemicals such as natural gas,oil and No flammable chemicals
gasoline. present.
Vegetation Vegetation growing across and blocking more than No vegetation blocking opening
1090 of the basin opening. to basin.
Vegetation growing in inlet/outlet pipe joints that is No vegetation or root growth
more than six inches tall and less than six inches present.
' apart.
Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than
per three feet of basin length. surface film.
' Catch Basin Cover Cover Not in Place Cover is missing or only partially in place.Any open Catch basin cover is closed
catch basin requires maintenance.
Locking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper
Not Working person with proper tools.Bolts into frame have less tools.
than 1/2 inch of thread.
Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one
Remove applying 80 lbs.of lift;intent is keep cover from maintenance person.
sealing off access to maintenance.
Ladder Ladder Rungs Ladder is unsafe due to missing rungs,misalignment, Ladder meets design standards
Unsafe rust,cracks,or sharp edges. and allows maintenance person
safe access.
Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design
(If Applicable) standards.
Trash and Debris Trash and debris that is blocking more than 20%of Grate free of trash and debris.
grate surface.
Damaged or Grate missing or broken member(s)of the grate. Grate is in place and meets
Missing. design standards.
NO. 6 DEBRIS BARRIERS (E.G.,TRASH RACKS)
Maintenance Defect Condition When Maintenance is Needed Results Expected When
Components Maintenance is Performed.
rGeneral Trash and Debris Trash or debris that is plugging more than 20%of Barrier clear to receive capacity
the openings in the barrier. flow.
Metal Damaged/Missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more
Bars. than 3/4 inch.
' Bars are missing or entire barrier missing. Bars in place according to
design.
Bars are loose and rust is causing 50%deterioration Repair or replace barrier to
to any part of barrier. design standards.
9/1/98 1998 Surface Water Design Manual
A-6
APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
NO. 7- ENERGY DISSIPATERS
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Components Maintenance is Performed.
External:
Rock Pad Missing or Moved Only one layer of rock exists above native soil in Replace rocks to design
Rock area five square feet or larger,or any exposure of standards.
native soil.
Dispersion Trench Pipe Plugged with Accumulated sediment that exceeds 2000 of the Pipe cleaned/flushed so that it
Sediment design depth. matches design.
' Not Discharging Visual evidence of water discharging at Trench must be redesigned or
Water Properly concentrated points along trench(normal condition rebuilt to standards.
is a'sheet flow"of water along trench). Intent is to
prevent erosion damage.
' Perforations Over 1/2 of perforations in pipe are plugged with Clean or replace perforated pipe.
Plugged. debris and sediment.
Water Flows Out Maintenance person observes water flowing out Facility must be rebuilt or
' Top of"Distributor" during any storm less than the design storm or its redesigned to standards.
Catch Basin. causing or appears likely to cause damage. s
Receiving Area Water in receiving area is causing or has potential No danger of landslides.
Over-Saturated of causing landslide problems.
Internal:
Manhole/Chamber Wom or Damaged Structure dissipating flow deteriorates to 1/2 or Replace structure to design
Post.Baffles,Side original size or any concentrated wom spot standards.
of Chamber exceeding one square foot which would make
structure unsound.
Other Defects See"Catch Basins"Standard No.5 See"Catch Basins"Standard No.
5
' 1998 Suriaee Water Design Manual 9/1/9S
A-7
tAPPENDIX A 'v1AIN7ENA:XiCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
' NO. 8- FENCING
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Components Maintenance is Performed
General Missing or Broken Any defect in the fence that permits easy entry Parts in place to provide adequate
Parts to a facility. security.
Erosion Erosion more than 4 inches high and 12-18 No opening under the fence that
inches wide permitting an opening under a exceeds 4 inches in height.
fence.
Wire Fences Damaged Parts Post out of plumb more than 6 inches. Post plumb to within 1-1/2 inches.
' Top rails bent more than 6 inches. Top rail free of bends greater than
1 inch.
Any part of fence(including post,top rails,and Fence is aligned and meets design
fabric)more than 1 foot out of design alignment. standards.
Missing or loose tension wire. Tension wire in place and holding
fabric.
Missing or loose barbed wire that is sagging Barbed wire in place with less than
more than 2-1/2 inches between posts. 3/4 inch sag between post.
Extension arm missing,broken,or bent out of Extension arm in place with no
shape more than 1 112 inches. bends larger than 3/4 inch.
Deteriorated Paint or Part or parts that have a rusting or scaling Structurally adequate posts or
Protective Coating condition that has affected structural adequacy. parts with a uniform protective
coating.
Openings in Fabric Openings in fabric are such that an 8-inch- No openings in fabric.
diameter ball could fit through.
NO
. - GATES
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Performed
General Damaged or Missing Missing gate or locking devices. Gates and Locking devices in
Members place.
Broken or missing hinges such that gate cannot Hinges intact and tubed.Gate is
be easily opened and closed by a maintenance working freely.
person.
Gate is out of plumb more than 6 inches and Gate is aligned and vertical.
more than 1 foot out of design alignment.
' Missing stretcher bar,stretcher bands,and ties. Stretcher bar,bands and ties in
place.
Openings in Fabric See"Fencing"Standard No.8 See"Fencing"Standard No.8
1 9/1/98 1998 Surface Water DesiLm Manual
A-8
' .APPENDIX A MAINI-EINANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
' NO. 10- CONVEYANCE SYSTEMS (PIPES & DITCHES)
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Performed
Pipes Sediment&Debris Accumulated sediment that exceeds 20%of the Pipe cleaned of all sediment
diameter of the pipe. and debris.
Vegetation Vegetation that reduces free movement of water All vegetation removed so water
through pipes. flows freely through pipes.
Damaged Protective coating is damaged;rust is causing Pipe repaired or replaced.
more than 50%deterioration to any part of pipe.
' Any dent that decreases the cross section area of Pipe repaired or replaced.
pipe by more than 2000.
Open Ditches Trash&Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from
square feet of ditch and slopes. ditches.
Sediment Accumulated sediment that exceeds 20%of the Ditch cleaned/flushed of all
design depth. sediment and debris so that it
matches design.
Vegetation Vegetation that reduces free movement of water Water flows freely through
through ditches. ditches.
' Erosion Damage to See"Ponds"Standard No. 1 See"Ponds"Standard No.1
Slopes
Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design
Place or Missing(If the rock lining. standards.
Applicable).
Catch Basins See"Catch Basins:Standard No.5 See"Catch Basins"Standard
No.5
Debris Barriers See"Debris Barriers"Standard No.6 See"Debris Barriers'Standard
(e.g.,Trash Rack) No.6
NO. 11 - GROUNDS (LANDSCAPING)
Maintenance Defect Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Performed
General Weeds Weeds growing in more than 20%of the landscaped Weeds present in less than 5%
(Nonpoisonous) area(trees and shrubs only). of the landscaped area.
' Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation
vegetation. present in landscaped area.
Trash or Litter Paper,cans,bottles,totaling more than 1 cubic foot Area clear of litter.
' within a landscaped area(trees and shrubs only)of
1,000 square feet.
Trees and Shrubs Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than
broken which affect more than 25%of the total 51%of total foliage with split or
foliage of the tree or shrub. broken limbs.
Trees or shrubs that have been blown down or Tree or shrub in place free of
I knocked over. injury.
Trees or shrubs which are not adequately supported Tree or shrub in place and
or are leaning over,causing exposure of the roots. adequately supported;remove
any dead or diseased trees.
1998 Surface Water DesiSn Manual 9/i/98
A-9
APPENDIX A VIAINTENAINCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
NO. 12 -ACCESS ROADS/ EASEMENTS
' Maintenance Defect Condition When Maintenance is Needed Results Expected When
Component Maintenance is Performed
General Trash and Debris Trash and debris exceeds 1 cubic foot oer 1,000 Roadway free of debris which
square feet i.e.,trash and debris would fill up could damage tires.
one standards size garbage can.
Blocked Roadway Debris which could damage vehicle tires(glass Roadway free of debris which
or metal). could damage tires.
Any obstruction which reduces clearance above Roadway overhead dear to 14 feet
road surface to less than 14 feet high.
Any obstruction restricting the access to a 10 to Obstruction removed to allow at
12 foot width for a distance of more than 12 feet least a 12 foot access.
or any point restricting access to less than a 10
foot width.
Road Surface Settlement, Potholes, When any surface defect exceeds 6 inches in Road surface uniformly smooth
Mush Spots, Ruts depth and 6 square feet in area. In general,any with no evidence of settlement,
surface defect which hinders or prevents potholes,mush spots,or ruts.
maintenance access.
Vegetation in Road Weeds growing in the road surface that are Road surface free of weeds taller
Surface more than 6 inches tall and less than 6 inches than 2 inches.
tall and less than 6 inches apart within a 400-
square foot area.
Modular Grid Build-up of sediment mildly contaminated with Removal of sediment and disposal
Pavement petroleum hydrocarbons. in keeping with Health Department
recommendations for mildly
contaminated soils or catch basin
sediments.
Shoulders and Erosion Damage Erosion within 1 foot of the roadway more than 8 Shoulder free of erosion and
Ditches inches wide and 6 inches deep. matching the surrounding road.
Weeds and Brush Weeds and brush exceed 18 inches in height or Weeds and brush cut to 2 inches
hinder maintenance access. in height or cleared in such a way
as to allow maintenance access.
9/1/98 1998 Surface Water Design Vfanual
A-10
APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES
NO. 13-WATER QUALITY FACILITIES (CONTINUED)
D.)Wetvaults
Maintenance Defect Condition When Maintenance is Needed Results Expected When
' Component Maintenance is Performed
Wetvault Trash/Debris Trash and debris accumulated in vault,pipe or Trash and debris removed from
Accumulation inlet/outlet,(includes floatables and non- vault.
floatables).
' Sediment Accumulation Sediment accumulation in vault bottom that Removal of sediment from vault.
in Vault exceeds the depth of the sediment zone plus 6-
inches.
' Damaged Pipes Inlet/outlet piping damaged or broken and in Pipe repaired and/or replaced.
need of repair.
Access Cover Cover cannot be opened or removed,especially Pipe repaired or replaced to
Damaged/Not Working by one person. proper working specifications.
Vault Structure Vault:Cracks wider than 1/2-inch and any No cracks wider than 1/4-inch at
Damaged evidence of soil particles entering the structure the joint of the inlet/outlet pipe.
through the cracks,or maintenance/inspection Vault is determined to be
personnel determines that the vault is not structurally sound.
structurally sound.
Baffles Baffles corroding,cracking,warping and/or Repair or replace baffles to
showing signs of failure as determined by specifications.
maintenance/inspection staff.
' Access Ladder Damage Ladder is corroded or deteriorated,not functioning Ladder replaced or repaired to
properly,missing rungs,has cracks and/or specifications,and is safe to
misaligned. use as determined by inspection
personnel.
1998 Surface Water Design Manual 9/1/98
A-13