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F-010 Drainage Reports EMERIO ENGINEERING•SURVEYING• DESIGN Drainage Report Lot 1 of 5 Lot Subdivision at Tax Map 251E 07CA Tax Lot 100, 2902, 3000 Lake Oswego, Oregon Emerio Project Number: 0980-001 City of Lake Oswego Permit Numbers: LU 23-0002 Date: 12/23/2022 Rev 1: 09/14/2023 p PROF ��G N 81153PE te—DocuSigned by: LP7zi ER G� :y EXPIRES: 12/31/2023 Prepared For: Prepared By: Kelly McCall Joshua Ayers, PE Renaissance Homes Emerio Design, LLC 16771 Boones Ferry Road 6445 SW Fallbrook PI, Suite 100 Lake Oswego, Oregon 97035 Beaverton, Oregon 97008 kmccall@renaissance-homes.com joshua@emeriodesign.com (503) 746-8812 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Table of Contents: APPENDIX A (1) Vicinity Map APPENDIX B (1) Soil Classification Map-"Soils Survey for Clackamas County" (2) Curve Number Table (3) Infiltration Tests (Rapid Soil Solutions, July 8, 2021 and May 18, 2022) (4) HydroCAD Plot (5) StormTech SC-740 Chamber Specs APPENDIX C (1) Site Map 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Project Overview and Description The project site is located on the south side of SW Baleine Street between the southeast corner of the intersection of SW Kimball Street & Baleine Street and the southwest corner of the intersection of Inverurie Road. The existing condition is a large undeveloped lot. Five lots will be created with a new single-family home and attached garage on each lot. All new impervious area to be created by this project on this lot will be directed to new onsite stormwater systems. This report addresses the stormwater management for Lot 1 and includes the analysis of the shared driveway. Refer to Appendix C(1) for site map. The property is zoned R-7.5 (Residential, 7,500 SF lots) with a lot size of 9,605 SF. The proposed project will address the following elements of the Lake Oswego Stormwater Management Manual: Site Assessment and Feasibility Analysis, and Onsite Stormwater Management. Site Assessment and Feasibility Analysis: The proposed site is composed of Salem silt loam, hydrologic soil group B. Preliminary investigation by Rapid Soil Solutions on July 8, 2021, measured infiltration rates of 3 in/hr at 8 feet below ground surface. At a test pit closer to the shared driveway and southern lots 4 and 5 of the development, infiltration testing was performed on May 11, 2022, and yielded a measured rate of 720 in/hr at 5 feet below ground surface. During field exploration groundwater was not encountered in test pits; however, Portland area groundwater mapping shows groundwater to be approximately 40 feet below ground surface. Onsite stormwater management is proposed for this site. Onsite Stormwater Management — Shared Driveway: To achieve onsite stormwater management for the shared driveway, a drywell system located in an easement on Lot 4 is proposed to infiltrate 100% of the driveway runoff during the 10-year 24-hour design storm. A lynch style catch basin with an 18-inch sump will provide pretreatment prior to the DEQ defined UIC (drywell). Reference drywell system dimensions and modeling data below. Input Data: Impervious Area: 8,095 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.00 Feet Drywell Bottom Elevation: 219.00 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.0 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.14 CFS Peak Flow Rate in Infiltration Device: 0.14 CFS Peak Water Surface Elevation: 218.99' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 5' below finish grade. Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. Onsite Stormwater Management — Lot 1: The site assessment meets requirements that allow on-site stormwater management and infiltrating 100% of the 10-year 24-hour design storm. To achieve onsite stormwater management, an infiltration system of StormTech SC-740 chambers is proposed to receive roof runoff. The driveway will be graded to drain to a trench drain that routes to a lynch style catch basin/silt trap before entering the chamber system. Infiltration Chamber Analysis: The StormTech SC-740 chambers are modeled to infiltrate 100% of the design storm roof and driveway runoff using HydroCAD V10.0 Stormwater Modeling Software. This analysis appears in Appendix B(4). The chambers will be in an alignment of one lengthwise row of three chambers. The design storm used in the model is the 10- Year 24-Hour storm with a depth of 3.2 inches in a Type 1A distribution. Reference StormTech SC-740 system dimensions and modeling data below. Input Data: Impervious Area: 3,463 SF Curve Number: 98 Time of Concentration: 5 Minutes StormTech SC-740 Quantity: 3 EA Assumed Finish Grade: 224.00 Feet StormTech Chamber Invert: 216.50 Feet Drain Rock Invert: 216.00 Feet Drain Rock Length: 24.98 Feet Drain Rock Width: 6.25 Feet Drain Rock Height: 3.50 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 3.0 Inches/Hour Design Infiltration Rate: 1.5 Inches/Hour Factor of Safety: 2 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Design Storm: Type 1A, 10-year Design Storm Depth: 3.20 Inch in 24-hours Output Data: Peak Flow Rate from Impervious Area: 0.059 CFS Peak Flow Rate in Infiltration Device: 0.012 CFS Peak Water Surface Elevation: 218.86 Feet Draw Down Time: 5 hours from end of storm As shown in the model results, the peak water surface elevation for this design storm event is 2.86 feet above the invert of the StormTech chambers, within the rock section. See attached specifications from the manufacturer in Appendix B(5). Overflow Discharge: In the event of flows greater than the capacity of the StormTech chamber system, flows will bubble up at the downspout connection and flow overland east across the north yard and adjacent lots toward an existing wetland. UIC Review with Oregon DEQ: This project will use a UIC system that receives runoff from residential driveway areas for the onsite Lot 1 system as well as the shared driveway system; therefore, registration and approval with DEQ is required under Authorization by Rule requirements. Pretreatment of the driveway areas will be achieved by providing the minimum required 18 inches of sump below the snout in a silt trapped basin. Engineering Conclusions Based on the results of this analysis, the proposed stormwater system meets the 2020 City of Lake Oswego Stormwater Management Manual standards. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Appendix A: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix A(1) Vicinity Map I 1 t. -.�:.�.�[ifSllYStd]Spfil1�.RJ..._.I ` � �� \ L \ • .nt I, , Al r,J.., rl '. - ,• /',,,khan Sl,d ••. _ l nl SITE 1,r,,nl K I Lae h I _ P.�0.13121 f,l :^�akl,Ja Village it F;Tfi-E,e1 Meetesaorl ` 1-n :N Shal.uspeale Sr.::::-.) 1 / o: Lake Wove _ `,L 1� Iinga n ft catic.,w..,y Elenrn Wry ,'�'I SI ,I,La,'�_'p;,_-_-_. I. •;r.l t School I • . T'" -fwT, 'f'^• +`✓, 0 �` rll ,ye= _ IC".— ti0eP_: I C R Lakr, .I eye 1 hl '� FIIW - _ n �. P, we,.a cc,., rol W.71j,/,0. y j v a �� - 1 II j. :! Manton,, I '' t 3 r ,r a. i rr•Rarfi 1�o°Io} .., i i �` p1\ r i i 4 j 1-1 I; - —3 �• C . F 0' b i Ll jl'- .,rh of Pam, .II—ll. .l Pr i t 2 j I 4 Lyn old Spnnre 1 -..L f 1 ' ''very„ Nabeal AP Vilest �,^ r / Vol n'. ,r,,,i,r,.1 W.., i ! _ p1 ',., Chapman Way eS • wJ e :' ,,, - ew \ Cobb .,Itrl r' rr. 4 ,y� b r"� Way .n ! 1 e ey �[n j(,. p�\ - ..Vn,w"x,a sl 1 wlCh $t • The Children: Z i �1 7 'h. T \ 11 en St Se [O• \'' l Hiul A<atkeny �O�a `. Ln wlllo 11'•. I L 9J VV F-"'st Cl , I J U I _) T f N�.t o Jrt 6W I 7f h\�J//.,..LJeLIs 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix B(1) Soil Classification Map . .-zfq, rIr% -.1;•k - ...c,.., , . , — .. ., -.... .,14 -- -, - ..' _-.-r.•--ii.k.g-,-..i'l 111.''.4•%•••44.VA •'•'la. . 1...,' - 4,04-,, S.•ticL 't •.-,"•' .,..A. .s".E• 4C0IMI,I M NP-- .'..,-- 4 r p ---- . . 4 • . - • . e *, r . IMW C1a i.161. ,. it1. ,, AV' i 1.* ... . ..vs* r w`ik, - .., ' ....4..,: sr lir : II s-'i :; '`‘) ‘1,.., '.. .i!.•*, ....Ill. ; . '4'. •.' 1 " . . . ,. • ..h ' ' . . , . ", -: ! - ..1... s • I, 7'. . • - ' _ __ • 4. . VI , 4' t• is. • f 11: - - l'i..,. V...• '1 44,'' . 'Al•----' • - '' : . ''Y' :!,;.7,'..tl 4"--'••••It ' ••••,,-• , • :'sy ir . ' 'l'' ' :S.. . • .. 1.' ;••,1%, i' ' ( .1414....; '. ' NI, ) . •, — al .4:-.. isw '04.,44,y" "e, • ,... , ' lir, • 41 ...- . , 'v. -) .0'• ,ie,.. ........L :i ..e - ., . . "A• • ' ---d: :Iiiikeki, .4! 1•• ).. -. .. lir ..-ti. . I. t N• ' i- I •c.'" .' " A •• lig4 1 .• liNillir%t. '' . . l) Table. tiyilealaini soil Group simian.ny nap ism 0 Summary by Map Unit-dackainas County Area,Oreuott(011010) Summary by Map Unit—Clackamas County Area,Oregon(OR610) 4 Map unit symbol Map unit name Ratins Acres in A01 Percent of A01 25 Cove silty day barn D 0.7 31.5% 76B Salem silt loam,0 to 7 percent slopes B 1.4 68.5% Totals for Area of Interest 2.1 100.08/0 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B(2) Curve Number Table RUNOFF CURVE NUMBERS (TR55) Table 2-2a: Runoff curve numbers for urban areas RUNOFF CURVE NUMBERS (TR55) _ Table 2-2a: Runoff curve numbers for urban areas 1 Cover description CN for hydrologic soil group Average percent impervious Cover type and hydrologic condition area2 A B C D Fully developed urban areas (vegetation Use CN = 89 for Cove silty established) clay loam — Open space (lawns, parks, golf courses, cemeteries, etc.) 3: Poor condition (grass cover <50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover >75%) 39 1 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding Use CN = 79 for Salem silt - right-of-way) loam Paved; open ditches (including right-of-way) 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: _ Natural desert landscaping (pervious areas only) 4 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: _ Commercial and business 85 89 92 94 95 _ Industrial 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 6445 SWFallbrook Place,Suite too • Beaverton,OR 97008 • emeriodesign.com Matt Boggs APPENDIX B(3) Project Manager New Look Development E—Matt@NewLookDev.com P—(503)577-2646 8 July 2021 Re: Infiltration testing at empty lot next to 15868 SW Kimball Street, Lake Oswego OR Field Investigation: Rapid Soil Solutions (RSS) has attempted to performed one (1) infiltration tests. Figure 1 below shows the project site location. Soils found on site match those in by DOGMI. RSS found dry stiff fine-grained soils SW Baleine St 1— cn rn 15811 15825 15879 15868 Figure 1 Infiltration Testing: RSS performed the testing as per the City of Lake Oswego storm water manual. RSS shows on our infiltration sheet the pre-soak and testing. RSS found the rate to be 3in/hr. Groundwater Based upon the Portland area ground water map it is 40ft below the site. fix. ,l ? 7 .? USGS 5098 The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, I ‘rp PROic r G�N�F,Qs�O ' 19744 PE i2 •REGON 1/(Y15, 94\ -� ��1 C. MPN4' EXPIRES: 3 /-!di Z Mia Mahedy, PE GE. Rapid SoiloI irtions IIIC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results - — 1 4 ', t•• - « - . , HA#1 'er f‘. v... J . IL 111. . . -"47 . •Aii: ...._4:3 4 .Ilt N `i Preliminary Information SW Kimball St,Lake Performed By: Location: Oswego, OR; east of (Supervised by Mia Olenka Duncan 15868 SW Kimball St Mahedy,PE,GE) Date&Time: 7/6/21 at 12:30 Gm Instrument Used: Hand au:er Weather: 80°,mostly sunny Depth: 8 ft HA#1 A 4 hour presoak was started at 8:30 am with 16"of water. All 16"had drained at the end of the presoak, and the test was be_un at 12:30 .m. Soil Profile Detail Depth(ft) Description 0-1' Topsoil 1-3' Barely damp medium brown clayey silt 3-3.5' Coarse gravel with fine grained clay/silts 3.5-8' Barely damp beige clay Time Measurement(inches) Level Refilled To(inches) Rate (inches/hour) 12:30 - 16 - 1 10.75 - 10.5 1:30 8.5 12.5 4.5 2 10.5 13 4 2:30 11 - 4 3 6.25 11.5 9.5 3:30 10 - 3 Site Infiltration Rate(inches/hour) 3 Rapid I SoilSolOtions INC 503-816-3689 I mia@rapidsoilsolutions.com APPENDIX B(4) 0 <4B> LI 1 Share Drive U U A AN3 SC-740 chambers Drywell Subcat Reach 'on• Link Routing Diagram for 0980-001 Baleine HydroCAD Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1: Lot 1 Runoff = 0.059 cfs @ 7.88 hrs, Volume= 856 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description 3,463 98 roof impervious 3,463 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1 : Lot 1 Hydrograph 0.065= •Runoff 0.06 10.059 cfs @ 7.88 hrs Type IA 24 1r-- 0.055 005_ 10yearRainfalI 320"-- 0.045_ Runoff Area=3,463 sf 0.04- Runoff Val Ume=856Hcf 3 0.035, j Runoff''Depth=2.97" " O025= Tc=5.0 min 0.02= C V=0i98 0.015 � �� 0.01 0.005 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 4B: Shared Drive Runoff = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 8,095 98 impervious, dwy 8,095 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4B: Shared Drive Hydrograph 0.15 I i I i i I I •Runoff I I0.139cfs@7.58hrsI I 0.14�' y _ i I T 24-hr-- 0.13 I I I 0.12_' __�_ j 1-0-year RairyfarC=3: 0"= 0.11'" Runoff Area=8,095 sf 0.1��) Runoff Volume=2,002 cf 0.09 Runoff Depths=2.97" �° 0.07 � Tc=�5.0 m i n 0.06_ CN=0/98 0.05 0.04='' I' %' 0.03 ' 0.02_' 1 0.010�/ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 sin 04804 ©2018 HydroCAD Software Solutions LLC Page 4 Summary for Pond 1 P: SC-740 chambers Inflow Area = 3,463 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.059 cfs @ 7.88 hrs, Volume= 856 cf Outflow = 0.012 cfs @ 10.87 hrs, Volume= 856 cf, Atten= 80%, Lag= 179.6 min Discarded = 0.012 cfs @ 10.87 hrs, Volume= 856 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.86' @ 10.87 hrs Surf.Area= 156 sf Storage= 239 cf Plug-Flow detention time=246.6 min calculated for 856 cf (100% of inflow) Center-of-Mass det. time= 246.6 min ( 911.7 - 665.1 ) Volume Invert Avail.Storage Storage Description #1A 216.00' 135 cf 6.25'W x 24.98'L x 3.50'H Field A 546 cf Overall - 138 cf Embedded = 409 cf x 33.0% Voids #2A 216.50' 138 cf ADS_StormTech SC-740 +Capx 3 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.12'L = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap 273 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 216.00' 1.500 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.012 cfs @ 10.87 hrs HW=218.86' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.012 cfs) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 5 Pond 1 P: SC-740 chambers - Chamber Wizard Field A Chamber Model= ADS_StormTechSC-740+Cap(ADS StormTech®SC-740 with cap length) Effective Size=44.6"W x 30.0"H => 6.45 sf x 7.12'L = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap 3 Chambers/Row x 7.12' Long +0.81' Cap Length x 2 = 22.98' Row Length +12.0" End Stone x 2 = 24.98' Base Length 1 Rows x 51.0" Wide + 12.0" Side Stone x 2 = 6.25' Base Width 6.0" Base + 30.0" Chamber Height + 6.0" Cover = 3.50' Field Height 3 Chambers x 45.9 cf = 137.8 cf Chamber Storage 546.4 cf Field - 137.8 cf Chambers = 408.5 cf Stone x 33.0% Voids = 134.8 cf Stone Storage Chamber Storage + Stone Storage = 272.6 cf = 0.006 of Overall Storage Efficiency = 49.9% Overall System Size = 24.98'x 6.25'x 3.50' 3 Chambers 20.2 cy Field 15.1 cy Stone 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 6 Pond 1 P: SC-740 chambers Hydrograph ❑Inflow 0.065_ - i 0.059cfs@788hrs i ❑Discarded Inflow Area=3,463 sf 0.06- i%0.055� Peak Elev=218.86' Storage=239 cf 0.045� 0.04-' 0.035J 3 0.03_ LL o 0.025� 0.02 z 1 A 0.0151' -_ 0.012 cfs@10.87 hrs 0.01 0.005�� 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Pond 6P: Drywell Inflow Area = 8,095 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf Outflow = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf, Atten= 0%, Lag= 0.9 min Discarded = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.99'@ 7.89 hrs Surf.Area= 22 sf Storage= 7 cf Plug-Flow detention time=0.9 min calculated for 2,002 cf(100% of inflow) Center-of-Mass det. time= 0.9 min ( 666.0 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.00' 17 cf 2.33'D x 4.00'H Drywell Inside#2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.00' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.00' 360.000 in/hr Exfiltration over Wetted area above 218.00' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.139 cfs @ 7.89 hrs HW=218.99' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.139 cfs @ 0.01 fps) Pond 6P: Drywell Hydrograph / ❑Inflow 0.15 0 Discarded 10.139 cfs%9hrs 1 Inflow Area=8,095 sf 0.1 LL 0.13 Peak Elev=218.99' 0.12 0.11= % Storage=7 cf '`- 0.08= ° 0.070.06 0.05 0.04= 0.03 0.02 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) APP DIX B(5) StormTech SC-740 Chamber siiii Designed to meet the most stringent industry providing signers stormTech® standards for superior structural integrity while providing designers with a cost-effective method to save valuable land and protect Detention•Retention•Recharge water resources. The StormTech system is designed primarily to Subsurface Stormwater Management" be used under parking lots thus maximizing land usage for commercial and municipal • applications. ACCEPTS 4"(100 mm) SCH 40 PIPE FOR OPTIONAL INSPECTION PORT �I_I�I_I�I_I�I_IiI_I�I�1111�1�1�1�1�1�1�1�1�1�1�1� 1, A ,1 A 1, 1111, A ,1.i StormTech SC-740 Chamber (not to scale) Nominal Chamber Specifications /! III �o Q�\ tat am Size LxWxH �� 85.4 x 51.0 x 30.0 / t ° ' JWJLWhii"PI*i (2170x1295x762mm) I J_ _ _ _ _1_1_1 _ _1_ 1 Chamber Storage L8 I_I_I_I_I_I_I—I_I_190.7 (2300 mm)I_I_I—I_I_I_II_ 45.9 ft3(1.30 m3) 24"(610 mm)DIA.MAX SC-740 Chamber (203 mm) Minimum Installed Storage* SC-740 End Cap 74.9 ft3(2.12 m3) H 85.4"(2170 mm)INSTALLED Weight 74.0 Ibs (33.6 kg) 30.0" Shipping (762 mm) 30 chambers/pallet 60 end caps/pallet ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 12 pallets/truck H 51.0"(1295 mm) •-I Typical Cross THE INSTALLED CHAMBER SYSTEM SHALL PROVIDE CHAMBERS SHALL MEET ASTM F 2922-12"STANDARD THE LOAD FACTORS SPECIFIED IN THEAASHTO LRFD SPECIFICATION FOR POLYETHYLENE(PE)CORRUGATED Section Detail BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR WALLSTORMWATER COLLECTION CHAMBERS." EARTH AND LIVE LOADS,WITH CONSIDERATION FOR (not to scale) IMPACT AND MULTIPLE VEHICLE PRESENCES. WELL GRADED SOIL/AGGREGATE 3/4-2"(19-50 mm)CLEAN,CRUSHED,ANGULAR STON MIXTURES,<35%FINES. COMPACT IN 6"(150 mm) LIFTS TO 95%STANDARD PROCTOR DENSITY SEE SC-740 CHAMBER THE TABLE OF ACCEPTABLE FILL MATERIALS. ADS 601 GEOTEXTILE OR EQUAL PAVEMENT SC-740 END CAP �///(/////////////. //////// // // / IGRANULAR ///////////////////////// ///// 1 11-1 I I—I I FOR UNPAVED INSTALLATION WHERE 96„ — III 11 RUTTING FROM VEHICLES MAY OCCUR, 1 18"(460 mm)(2440 mm) INCREASE COVER TO 24(610 MM) III— M N. MAX. �• lil`i,1'• 1'•i 1'•1'•i 1'•r1'1 ' 11 1'c l 1 1' 1tti i�1'9.1'.6' 150 mm MIN. .•1 441.�•1._A14j • /•1� •��I, •1,1.1.1.1 . •I..�Y. •.� •i1 i1. i1� �•� •i �. • i1 , A 1iV1: III 1 •11 0l l' All—T ��:`•l l 4 AL 1l0eI lt!'•l1. AeN fit 1.all — ro •o� 4.� �Io • 0>/ • 1 �� •o •0 30"(762 mm)SC-740 1 U 1 1 I i .j 1 •y • 1: 1I1I *Ore 11�ill No I.ik 1:•C 111-11:tc-1I o o �IoO11 o 0� `I�2;c o lA Ol 1 14741, I,.r•1 .l1'. '.rilN. �101•�� • 11 .��11. • •1 1 DEPTH OF STONE III 1, 1�.0•"10:•o Io •o 1� •o�10 YI �• : ,.;•, . o�y�o Io 0 0 Ao•j 1}-7' 1 1 : 1 1 1 1 •1 • 1 1 1 .".1.''V/. n.1...A.,.l • 1 OBE DETERMINED _ �x I:i _G ♦r_G.�x �x� xJ • �a_J i__�.ix_I - 1 e H I I1 I I1 I II 1I 1IIIIIIIIIIIIIIIIII—III —III III III—III—III—I 11—I 1 I III- BY DESIGN ENGINEER* EI I I 1—I I 1I I 1I I 1I I I I I I H 111-1 I I 11-1 1-1 11-1 I I-1 I I-1 I I_ 6"(150 mm)MIN. I 11-111 111 111111-11 I—III—III—III—III I 1 I—III III III—i I I—III—III—I I I DESIGN ENGINEER IS RESPONSIBLE FOR 51"(1295 mm)MIN. ENSURING THE REQUIRED BEARING CAPACITY 6"(150 mm)MIN. 12"MIN.(305 mm)TYP OF SUBGRADE SOILS* THIS CROSS SECTION DETAILS THE REQUIREMENTS NECESSARY TO SATISFY THE LOAD FACTORS SPECIFIED IN THEAASHTO LRFD BRIDGE MADE IN THE U.S.A. DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS USING STORMTECH CHAMBERS SC-740 Cumulative Storage Volumes Per Chamber Storage Volume Per Chamber Assumes 40%Stone Porosity. Calculations are Based Bare Chamber and Stone Upon a 6"(152 mm)Stone Base Under the Chambers. Chamber Stone Foundation Depth Storage in.(mm) Depth of Water Cumulative Total System ft3(m3) 6(150) 12(305) 18(460) in System Chamber Storage Cumulative Storage 1 StormTech SC-740 45.9(1.3) 74.9(2.1) 81.7(2.3) 88.4(2.5) Inches(mm) Ft3(m3) Ft3(m3) Note:Storage volumes are in cubic feet per chamber.Assumes 40%porosity for the 42(1067) 4 45.90(1.300) 74.90(2.121) stone plus the chamber volume. 41 (1041) I 45.90(1.300) 73.77(2.089) Amount of Stone Per Chamber 40(1016) Stone 45.90(1.300) 72.64(2.057) Stone Foundation Depth 39(991) Cover 45.90(1.300) 71.52(2.025) 38(965) 45.90(1.300) 70.39(1.993) ENGLISH TONS(CUBIC YARDS) 6" 12" 18" 37(948) + 45.90 1.300 69.26(1.961) StormTech SC-740 3.8(2.8 yd3) 4.6(3.3 yd3) 5.5(3.9 yd3) 36(914) 45.90(1.300) 68.14(1.929) METRIC KILOGRAMS(METERS) 150 mm 305 mm 460 mm 35(889) 45.85(1.298) 66.98(1.897) StormTech SC-740 3450(2.1 m3) 4170(2.5 m3) 4490(3.0 m3) 34(864)38 45.6941 (1.294)86 65.7546(1.862)25 Note:Assumes 6"(150 mm)of stone above,and between chambers. 33(838) 45.41 (1.286) 64.46(1.825) 32(813) 44.81 (1.269) 62.97(1.783) Volume of Excavation Per Chamber 31 (787) 44.01 (1.246) 61.36(1.737) Stone Foundation De th 29(737) 43.06(1.219) 57.89(1.639) 6"(150 mm) 12"(305 mm) 18"(460 mm) 29(737) 41.98(1.189) 57.89(1.639) 28(711) 40.80(1.155) 56.05(1.587) StormTech SC-740 5.5(4.2) 6.2(4.7) 6.8(5.2) 27(686) 39.54(1.120) 54.17(1.534) Note:Volumes are in cubic yards(cubic meters)per chamber.Assumes 6"(150 mm) 26(660) 38.18(1.081) 52.23(1.479) of separation between chamber rows and 18"(460 mm)of cover. The volume of 25(635) 36.74(1.040) 50.23(1.422) excavation will vary as the depth of the cover increases. 24(610) 35.22(0.977) 48.19(1.365) 23(584) 33.64(0.953) 46.11 (1.306) STANDARD LIMITED WARRANTY OF STORMTECH LLC("STORMTECH"):PRODUCTS 22(559) 31.99(0.906) 44.00(1.246) (A) This Limited Warranty applies solely to the StormTech chambers and endplates manufactured 21 (533) 30.29(0.858) 41.85(1.185) by StormTech and sold to the original purchaser(the"Purchaser").The chambers and endplates 20(508) 28.54(0.808) 39.67(1.123) are collectively referred to as the"Products." (B) The structural integrity of the Products,when installed strictly in accordance with StormTech's 19(483) 26.74(0.757) 37.47(1.061) written installation instructions at the time of installation,are warranted to the Purchaser against 18(457) ( ) (0.997)24.89 0.705 35.23 defective materials and workmanship for one(1)year from the date of purchase.Should a de- fect appear in the Limited Warranty period,the Purchaser shall provide StormTech with written 17(432) 23.00(0.651) 32.96(0.939) notice of the alleged defect at StormTech's corporate headquarters within ten(10)days of the discovery of the defect.The notice shall describe the alleged defect in reasonable detail. 16(406) 21.06(0.596) 30.68(0.869) StormTech agrees to supply replacements for those Products determined by StormTech to be 15(381) 19.09(0.541) 28.36(0.803) defective and covered by this Limited Warranty.The supply of replacement products is the sole remedy of the Purchaser for breaches of this Limited Warranty.StormTech's liability specifically 14(356) 17.08(0.484) 26.03(0.737) excludes the cost of removal and/or installation of the Products. 13(330) 15.04(0.426) 23.68(0.670) (C) THIS LIMITED WARRANTY IS EXCLUSIVE.THERE ARE NO OTHER RESPECT TO THE PRODUCTS,INCLUDING NO IMPLIEDWARRANTIES WITH WARRANTIES OF 12(305) 12.97(0.367) 21.31 (0.608) MERCHANT-ABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE. 11 (279) 10.87(0.309) 18.92(0.535) (U) This UNDERted Warranty only applies NO CIRCUMSTANCES,to the Products when the Products are installed SHALL THE PRODUCTS BE INSTALLED NinAa single layer. 10(254) 8.74(0.247) 16.51 (0.468) MULTI-LAYER CONFIGURATION. 9(229) 6.58(0.186) 14.09(0.399) (E) No representative of StormTech has the authority to change this Limited Warranty in any manner or to extend this Limited Warranty.This Limited Warranty does not apply to any person other than 8(203) 4.41 (0.125) 11.66(0.330) to the Purchaser. 7(178) 2.21 (0.063) 9.21 (0.264) (F) Under no circumstances shall StormTech be liable to the Purchaser or to any third party for prod- uct liability claims;claims arising from the design,shipment,or installation of the Products,or 6(152) 0 6.76(0.191) the cost of other goods or services related to the purchase and installation of the Products.For this Limited Warranty to apply,the Products must be installed in accordance with all site condi- 5(127) 0 5.63(0.160) tions required by state and local codes;all other applicable laws;and StormTech's written in- 4(102) Stone Foundation 0 4.51 (0.125) stallation instructions. (G) THE LIMITED WARRANTY DOES NOT EXTEND TO INCIDENTAL,CONSEQUENTIAL,SPE- 3(76) 0 3.38(0.095) CIAL OR INDIRECT DAMAGES.STORMTECH SHALL NOT BE LIABLE FOR PENALTIES OR 2(51) 0 2.25(0.064) LIQUIDATED DAMAGES,INCLUDING LOSS OF PRODUCTION AND PROFITS;LABOR AND MATERIALS;OVERHEAD COSTS;OR OTHER LOSS OR EXPENSE INCURRED BY THE 1 (25) y 0 1.13(0.032) PURCHASER OR ANY THIRD PARTY.SPECIFICALLY EXCLUDED FROM LIMITED WAR- RANTY COVERAGE ARE DAMAGE TO THE PRODUCTS ARISING FROM ORDINARY WEAR Note:Add 1.13 cu.ft.(0.032 m3)of storage for each additional AND TEAR;ALTERATION,ACCIDENT,MISUSE,ABUSE OR NEGLECT;THE PRODUCTS BEING SUBJECTED TO VEHICLE TRAFFIC OR OTHER CONDITIONS WHICH ARE NOT inch(25 mm)of stone foundation. PERMITTED BY STORMTECH'S WRITTEN SPECIFICATIONS OR INSTALLATION INSTRUC- TIONS;FAILURE TO MAINTAIN THE MINIMUM GROUND COVERS SET FORTH IN THE INSTALLATION INSTRUCTIONS;THE PLACEMENT OF IMPROPER MATERIALS INTO THE PRODUCTS;FAILURE OF THE PRODUCTS DUE TO IMPROPER SITING OR IMPROPER SIZING;OR ANY OTHER EVENT NOT CAUSED BY STORMTECH.THIS LIMITED WAR- RANTY REPRESENTS STORMTECH'S SOLE LIABILITY TO THE PURCHASER FOR CLAIMS RELATED TO THE PRODUCTS,WHETHER THE CLAIM IS BASED UPON CON- TRACT,TORT,OR OTHER LEGAL THEORY. 20 Beaver Road,Suite 104 I Wethersfield I Connecticut 106109 860.529.8188 1888.892.2694 I fax 866.328.8401 I fax 860-529-8040 I www.stormtech.com Op Printed in U.S.A. ©Copyright.All rights reserved.StormTech LLC,2007 Printed on recycled paper r66) S16-090508 Appendix C: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Z O NOTES: HCD o W Z LU I. THE EXISTENCE AND LOCATION OF ANY UNDERGROUND UTILITIES OR W Q <O Ce STRUCTURES SHOWN ON THESE PLANS ARE OBTAINED BY A SEARCH .— - ` O OF AVAILABLE RECORDS. TO THE BEST OF OUR KNOWLEDGE, THERE / 12 0 _ ARE NO EXISTING UTILITIES EXCEPT THOSE SHOWN ON THESE PLANS. / I... N THE CONTRACTOR IS REQUIRED TO TAKE DUE PRECAUTIONARY — \ \ O O o O MEASURES TO PROTECT THE UTILITY LINES SHOWN ON THESE DRAWINGS. THE CONTRACTOR FURTHER ASSUMES ALL LIABILITY AND / \ "/ -' W r Nw RESPONSIBILITY FOR THE UTILITY PIPES, CONDUITS OR STRUCTURES BALEINE ST > ( O SHOWN OR NOT SHOWN ON THESE DRAWINGS. VJ ( G G , I 0 N O (/) 2. INFILTRATION SYSTEM SHALL BE LOCATED A MINIMUM OF ID FROM M w w w 1w�:}'` w w"�� w / w \ w w w w w a O O BUILDINGS AND A MINIMUM OF 5'FROM PROPERTY LINES AS �• MEASURED FROM THE EDGE OF DRAIN ROCK \ / \ _ / . . \ \ W 2 F 3. BUILDING CRAWL SPACE DRAIN LINE TO BE DAYLIGHTED. I�/777� 3 \ /- _ - - Z Q O < 4. ROOF DRAIN CONNECTION SHOWN IN APPROXIMATE LOCATION. �� 1 �� / \. J X LJ REFER TO ARCHITECTURAL PLANS FOR ACTUAL LOCATION. I/✓ X < O l I _ 3 / PROPOSED(3)STORMTECH SC-740 CHAMBERS / GI I ,'�* 1 \ �� I m ~ I / - �- - FOR ROOF&DRIVEWAY DRAIN ONLY. CONNECT 1 I w� SITE NOTES: If/ ALL INCOMING PLUMBING TO LOWER PORTS. �' 0 ALL DIMENSIONS AND SQUARE FOOTAGE ARE ✓ /1 \ } r G., APPROXIMATE FIGURES. / I CONTRACTOR TO ENSURE DRIVEWAY SLOPE TO DRAIN �/ I PROPOSED 875G 1 �\ — AWAY FROM THE PROPOSED GARAGE AND SHEET FLOW / II ETAI CATCH HE EIET)) m (SEE D THIS SHE ip' TO TRENCH DRAIN AS SHOWN 3 - 2 i - ALL UTILITIES WILL BE INSTALLED UNDERGROUND \. / 1 1 W CONTRACTOR IS TO PROVIDE A "HUB & TACK" SURVEY �// ' \ / � 1p PRIOR TO SCHEDULING A FOOTING INSPECTION (/ W \ / — — Q ,1 3 I CONNECT TO ROOF \ J 6.'SLAB THICKNESS DRAIN SYSTEM '�y.•� `j ce a ✓ \ 0 O •, , €7.; G.91 INVERT _- 3 I 6"SLAB THICKNESS \ . , . ... . . . , • . . 1 TRENCH DRAIN DETAIL I/// I N.T.S. a 1 / 3 _ / \ V7 y /�' 0 12°MIN. SOLID SCREW ✓ / \ O N I� DOWN LID I/ 3/ _ O O LU O CC �I 2" ✓ I / 0 a yw,Lw 1 _ ��:1214IN. * J?I✓3°PIPE(MIN) I. / _,� o INLET 18"MIN. f//4 I�■ — — - I PIPE ELBOW OR HOOD) 1 / - N *THE BOTTOM OF THE INLET PIPE MUST NOT BE ✓ / \ I \ '0. LOWER THAN THE TOP OF THE OUTLET PIPE " " " " II//. . _ - 0.a 4 a 4 °i //�/' a d ,O , o I 1�. 4 r� / ` \ a / d / / 3 SILT TRAP BASIN DETAIL �-�v,� = �V.—�L\V��_V��L� j�_uVA. �A �Agjw��u�W� _� 0,$ _ lI H • ro ` _ _ _ __ __ ___ _ _LL __\C_�)Cu_n`_J/�_[_�)r�Ir ,/�[ }��_-/�[ ,)U_I,, J/� _ }� / /J�� }��/�'•�.I.}'�'•�•'_�.'. • I'r'.'•'•'• �pau�'E SC-740 STORMTECH CHAMBER INSTALLED PER - - - 1 - - \ �/��1��/ ��/ �„�uL�^�/\� ��/�� /�� /�� / )� /. \�/ LL Q MANUFACTURERS RECOMMENDATION 1 j r-• ` / �. m 2 II II- -II-II FG: 424.00' _ _ \ 4 II II II II II II II II II-I - 4 - as' III IY/ p 4 4 a \ 1)4 o 1 a 4 a a .6 g I I I 11, I I I I I I 111 11 11 L, a 4 a 4" I111=1111111111111111 L II V�'� Vw /w �/"� `v/ `� / `� �/ u v v 1 ✓ ooaoo�c�oochi- c�o��oo�ooLioo_ u�o�o/��ooLJo2�r" LJL 4 EL: 419.5'TOP OE ROCK //��/J _ _ L�_r� � � 2.5 -?Y - EL: 416.5'CHAMBER BASE ✓1 J - *'''*-'=''• °. - '- p $ a III II . . . . . . . . . . . . . . . . . . . . . . . . . . -".. EL: 416.0'INVERT OF ROCK --- - - ��` ° --" - '� Z,4 a5 1 II'fa I 11 11-111 1-11'I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III- - =11I=ii - a o DRAIN ROCK CONSISTING OF 1-1/2° L 15868 KIMBALL ST \ J/�� 1 ' TO 3 4°OPEN GRADED ROCK / ) - 4.25' / N ✓� TAX LOT 2901 GEOTEXTILE FABRIC ALL SIDES SHEET / m 10' 0 5' 10' 20' A o 1 o co STORMTECH SC-740 SECTION SCALE: 1" = 10' ZOFo Lz- N.T.S. C EMERIO ENGINEERING•SURVEYING• DESIGN Drainage Report Lot 2 of 5 Lot Subdivision at Tax Map 2S1E 07CA Tax Lot 100, 2902, 3000 Lake Oswego, Oregon Emerio Project Number: 0980-001 City of Lake Oswego Permit Numbers: LU 23-0002 Date: 12/23/2022 Rev 1: 09/14/2023 � c, I N FF 0 81153PE RcuS(ig�nedA by: C/O759,7295 g,,� s/5,Ly� q V P EXPIRES: 12/31/2023 Prepared For: Prepared By: Kelly McCall Joshua Ayers, PE Renaissance Homes Emerio Design, LLC 16771 Boones Ferry Road 6445 SW Fallbrook PI, Suite 100 Lake Oswego, Oregon 97035 Beaverton, Oregon 97008 kmccall@renaissance-homes.com joshua@emeriodesign.com (503) 746-8812 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Table of Contents: APPENDIX A (1) Vicinity Map APPENDIX B (1) Soil Classification Map-"Soils Survey for Clackamas County" (2) Curve Number Table (3) Infiltration Tests (Rapid Soil Solutions, July 8, 2021 and May 18, 2022) (4) HydroCAD Plots APPENDIX C (1) Site Map 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Project Overview and Description The project site is located on the south side of SW Baleine Street between the southeast corner of the intersection of SW Kimball Street & Baleine Street and the southwest corner of the intersection of Inverurie Road. The existing condition is a large undeveloped lot. Five lots will be created with a new single-family home and attached garage on each lot. All new impervious area to be created by this project on this lot will be directed to new onsite stormwater systems. This report addresses the stormwater management for Lot 2 and includes the analysis of the shared driveway. Refer to Appendix C(1) for site map. The property is zoned R-7.5 (Residential, 7,500 SF lots) with a lot size of 9,570 SF. The proposed project will address the following elements of the Lake Oswego Stormwater Management Manual: Site Assessment and Feasibility Analysis, Onsite Stormwater Management, and Design for Water Quality. Site Assessment and Feasibility Analysis: The proposed site is composed of Salem silt loam, hydrologic soil group B. Preliminary investigation by Rapid Soil Solutions on July 8, 2021, measured infiltration rates of 3 in/hr at 8 feet below ground surface. At a test pit closer to the shared driveway and southern lots 4 and 5 of the development, infiltration testing was performed on May 11, 2022, and yielded a measured rate of 720 in/hr at 5 feet below ground surface. During field exploration groundwater was not encountered in test pits; however, Portland area groundwater mapping shows groundwater to be approximately 40 feet below ground surface. Onsite stormwater management is proposed for this site. Onsite Stormwater Management — Shared Driveway: To achieve onsite stormwater management for the shared driveway, a drywell system located in an easement on Lot 4 is proposed to infiltrate 100% of the driveway runoff during the 10-year 24-hour design storm. A lynch style catch basin with an 18-inch sump will provide pretreatment prior to the DEQ defined UIC (drywell). Reference drywell system dimensions and modeling data below. Input Data: Impervious Area: 8,095 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.00 Feet Drywell Bottom Elevation: 219.00 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.0 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Design Storm Return Period: 10-Year Design Storm Depth : 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.14 CFS Peak Flow Rate in Infiltration Device: 0.14 CFS Peak Water Surface Elevation: 218.99' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 5' below finish grade. Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. Design for Water Quality — Lot 2: Water quality will be addressed for Lot 2 by routing all impervious areas to a flow- through planter box. The layer of growing medium (soil) within the planter will act as an orifice, limiting the flow of water as it infiltrates through this amended soil layer at a rate of 2.0 in/hr before collecting in an underdrain within a 12" rock layer. Per discussion with staff, flows will exit the planter box through a private lateral easement through the adjacent Lot 3 to the east and discharge to the delineated wetland area to the east. Flow-Through Planter Analysis: The flow-through planter was modeled using HydroCAD V10.0 Stormwater Modeling Software. This analysis appears in Appendix B(4). The water quality design storm used in modeling has a depth of 1 inch over 24 hours in a Type 1A distribution. Reference planter dimensions and modeling data below. Stormwater Modeling: Impervious Area: 3,728 SF Curve Number: 98 Time of Concentration: 5 Minutes Planter Surface Area: 63 SF Freeboard: 2" Minimum Storage Depth: 12" Topsoil Media Depth: 18" Amended Soil Infiltration Rate: 2.0 Inches/Hour Drain Rock Layer Thickness: 12" Drain Rock Void Ratio: 33% Design Storm: Type 1A, 10-year Design Storm Depth: 1 Inch in 24-hours 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Output Data: Peak Flow Rate from Impervious Area: 0.018 CFS Peak Flow Rate in Infiltration Device: 0.003 CFS As shown above, the planter is sized to meet water quality requirements for this project. Sizing was iterated to keep the peak water elevation just under the overflow outlet. Overflow Discharge: In the event of flows greater than the WQ capacity of the flow-through planter system, flows will reach the overflow outlet set 12" above the planter surface and be conveyed by pipe through and easement across Lot 3 and discharge to wetland. Engineering Conclusions Based on the results of this analysis, the proposed stormwater system meets the 2020 City of Lake Oswego Stormwater Management Manual standards. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Appendix A: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix A(1) Vicinity Map I 1 t. -.�:.�.�[ifSllYStd]Spfil1�.RJ..._.I ` � �� \ L \ • .nt I, , Al r,J.., rl '. - ,• /',,,khan Sl,d ••. _ l nl SITE 1,r,,nl K I Lae h I _ P.�0.13121 f,l :^�akl,Ja Village it F;Tfi-E,e1 Meetesaorl ` 1-n :N Shal.uspeale Sr.::::-.) 1 / o: Lake Wove _ `,L 1� Iinga n ft catic.,w..,y Elenrn Wry ,'�'I SI ,I,La,'�_'p;,_-_-_. I. •;r.l t School I • . T'" -fwT, 'f'^• +`✓, 0 �` rll ,ye= _ IC".— ti0eP_: I C R Lakr, .I eye 1 hl '� FIIW - _ n �. P, we,.a cc,., rol W.71j,/,0. y j v a �� - 1 II j. :! Manton,, I '' t 3 r ,r a. i rr•Rarfi 1�o°Io} .., i i �` p1\ r i i 4 j 1-1 I; - —3 �• C . F 0' b i Ll jl'- .,rh of Pam, .II—ll. .l Pr i t 2 j I 4 Lyn old Spnnre 1 -..L f 1 ' ''very„ Nabeal AP Vilest �,^ r / Vol n'. ,r,,,i,r,.1 W.., i ! _ p1 ',., Chapman Way eS • wJ e :' ,,, - ew \ Cobb .,Itrl r' rr. 4 ,y� b r"� Way .n ! 1 e ey �[n j(,. p�\ - ..Vn,w"x,a sl 1 wlCh $t • The Children: Z i �1 7 'h. T \ 11 en St Se [O• \'' l Hiul A<atkeny �O�a `. Ln wlllo 11'•. I L 9J VV F-"'st Cl , I J U I _) T f N�.t o Jrt 6W I 7f h\�J//.,..LJeLIs 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix B(1) Soil Classification Map --zir..1,1, PIF`: ....••.x:k ,V,"41%,.., ••• . . ' ''' 4 .:;• .14 "-- •r, . ,. -.! ...f.• ;. 't :- • •ftr-A ••iv •4,,. _ , ., _ A\ Ag.i. '...-.:4 - -4,. ., ... . ' • ,. r...t.AX .. . . . • ,,- s-4. a ... ,,. . . .. , *,.. ...... ...: 11....„71t. .,44.,„ . lotak .- pe....,- . •airarv-- ----I ...;. . ...... .r .. p, 40 4.1.4& i.-.4 ci4t. 4, .. ..., IL . .li s. . . 2- • i Pk 1 1•.:* .. ,i,. 1' . • % , I r 7:, t . . ! •.-. . . - _ __ iir . , . ... r i,,t - : ..S•,,•,, 4,41.•,- ',1 4.. .4 ' • - ' : ' '.Y. ".!--• tl 4"--.'- i• , . 1,,S i. • .4 P.11,:•' • ' •.65 .t le, . ..(' ,. ...•41.--3, : .:• •••• ,‘ ,..*, 3, • : .34.6.::: . .", - 14# ',VAS,. ,. . • ., .f '',.-r) • . , • . . - , . . 0 . .-t• 1).-''. '.. ) . ., — - ' tki,'• .ta . 4,6,A , . xi • 4C4V1/4..'-‘'I'•. .0'.4.; -"..L2__1111__Ik''' . 410. ::: ''• ..4,:: .;i.2,.=4•4 i . :•)•• . lir, _4. i •• - . i • • ' 01' -• ::•i4 • • ' . .10 -I P.,. .).• -• .. 1r A. . . . . \• . 1 ‘ A I . • "lt 11 . • ' '- ' '..' 11=1==i= ._ • I' . -i:- :, ,,,sic..._,.- ..e.. • •-- Tattle, limirologre Soil Group Summary fly Map IMP 0 summary by Map Unit-Oarkainas County Area,Oregon(011010) Summary by Map Unit—Clackamas County Area,Oregon(011610) 4 Mop unit symbol Map unit name Resins Acres in POI Percent of POI 25 Cove silty clay loam D 0.7 31.5% 76B Salem silt loam,0 to 7 percent slopes B 1.4 68.5% Totals for Area of Interest 2.1 100.0% 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B(2) Curve Number Table RUNOFF CURVE NUMBERS (TR55) Table 2-2a: Runoff curve numbers for urban areas RUNOFF CURVE NUMBERS (TR55) _ Table 2-2a: Runoff curve numbers for urban areas 1 Cover description CN for hydrologic soil group Average percent impervious Cover type and hydrologic condition area2 A B C D Fully developed urban areas (vegetation Use CN = 89 for Cove silty established) clay loam — Open space (lawns, parks, golf courses, cemeteries, etc.) 3: Poor condition (grass cover <50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover >75%) 39 1 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding Use CN = 79 for Salem silt - right-of-way) loam Paved; open ditches (including right-of-way) 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: _ Natural desert landscaping (pervious areas only) 4 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: _ Commercial and business 85 89 92 94 95 _ Industrial 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 6445 SWFallbrook Place,Suite too • Beaverton,OR 97008 • emeriodesign.com Matt Boggs Project Manager APPENDIX B(3) New Look Development E—Matt@NewLookDev.com P—(503)577-2646 8 July 2021 Re: Infiltration testing at empty lot next to 15868 SW Kimball Street, Lake Oswego OR Field Investigation: Rapid Soil Solutions (RSS) has attempted to performed one (1) infiltration tests. Figure 1 below shows the project site location. Soils found on site match those in by DOGMI. RSS found dry stiff fine-grained soils SW Baleine St 1— cn rn 15811 15825 15879 15868 Figure 1 Infiltration Testing: RSS performed the testing as per the City of Lake Oswego storm water manual. RSS shows on our infiltration sheet the pre-soak and testing. RSS found the rate to be 3in/hr. Groundwater Based upon the Portland area ground water map it is 40ft below the site. fix. ,l ? 7 .? USGS 5098 The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, I ‘rp PROic r G�N�F,Qs�O 19744 PE i2 •REGON 1/(}, 15, 94\ -� ��1 C. MPN4' EXPIRES: 3 /-!di Z Mia Mahedy, PE GE. Rapid SoiloI irtions IIIC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results - — 1 4 ', t•• - « - . , HA#1 'er f‘. v... J . IL 111. . . -"47 . •Aii: ...._4:3 4 .Ilt N `i Preliminary Information SW Kimball St,Lake Performed By: Location: Oswego, OR; east of (Supervised by Mia Olenka Duncan 15868 SW Kimball St Mahedy,PE,GE) Date&Time: 7/6/21 at 12:30 Gm Instrument Used: Hand au:er Weather: 80°,mostly sunny Depth: 8 ft HA#1 A 4 hour presoak was started at 8:30 am with 16"of water. All 16"had drained at the end of the presoak, and the test was be_un at 12:30 .m. Soil Profile Detail Depth(ft) Description 0-1' Topsoil 1-3' Barely damp medium brown clayey silt 3-3.5' Coarse gravel with fine grained clay/silts 3.5-8' Barely damp beige clay Time Measurement(inches) Level Refilled To(inches) Rate (inches/hour) 12:30 - 16 - 1 10.75 - 10.5 1:30 8.5 12.5 4.5 2 10.5 13 4 2:30 11 - 4 3 6.25 11.5 9.5 3:30 10 - 3 Site Infiltration Rate(inches/hour) 3 Rapid I SoilSolOtions INC 503-816-3689 I mia@rapidsoilsolutions.com Matt Boggs Project Manager New Look Development 7685 SW Cirrus Dr. 32F Beaverton, Oregon 97008 E—Matt@NewLookDev.com P—(503)577-2646 18 May 2022 Re: Infiltration testing for Kimball Street, Lake Oswego, OR Dear Mr. Boggs, Field Investigation: Rapid Soil Solutions (RSS) has performed a total of one (1) infiltration test. The figure below shows the site RSS found a mixture of fine-grained Missoula Flood Deposits, Off and fractured basalt. Testing was performed for future storm water design. Location shown below. o0 al, 15811 46 1 15825 $8 15879 - _ 15868 15921 Ael,, r Infiltration Testing and ground water Infiltration testing was performed as per the Lake Oswego Storm Water Manual 2018. The first hole was a test pit as the south side of the lot is fractured basalt and cobbles on 11 May 2022. The test was performed between proposed lots 4/5 and the rate was 720in/hr. See attached soils logs. Additional test holes were excavated between lots 1 and 2 and then on lot 3. Fine grained soils were found with the excavator. We returned on 13 May 2022 to hand excavate those holes using a hand augur for a better pre-soak and readings. RSS found the soils to be hard white elastic CLAY and when we excvated to a depth of 4ft and performed the four(4) hour pre-soak they did not drain at all. Ground water Based upon the USGS groundwater is within 40ft of the site. v.. urham1 I i-r USGS 2008-5059 Rapid I I So i L S o`w t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Test hole locations for lots 1-3 =• - Did not drain at all during FA ...,� e=-e� � ,, ` "m— ' .", . the pre-soak phase Q` _ e• - e e-- 4.#-=_ _ ' - .-eB�- a-- [ ; - —e 6 .- e. e. ®-- -- 0 0i= e, R �1 Q: HA#2, `.sue t1 e $. a =_ A; / ©j._bt - q - -, T.s • -; a _ . a. a-- a!-: 1 o �- _ ©-, e- , . -_r - ,,-.e. e- TI.. maw..*In --Conclusion RSS recommends onsite infiltration for lots 4 and 5. With lots 1-3 drainage being piped to storm water basin that is set aside on lot 4. The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, CEO PR0FF 4, Sol cr 19 44P O. 7•REGON ,- '1 GAY15 ` • 1 �41 C. MAN EXPIRES: /t- 2), /- Zdi 2_ Mia Mahedy, PE GE Rapid I I S o i L S o`V t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results .�, • {,-- .._ - .N N$7 .-. �� ,— i se- 5 S _ - �� .. -V -i .s.. vfva TL ua � _ Or- •- ,i-.. 0oit - - it so n - -, . a- °r ._ I-I .a. -- - - Preliminary Information Performed By: Location: Kimball Street (Supervised by Mia Rick Sands Mahedy, PE,GE) Date& Time: 5-11-22, 830 am Instrument Used: excavator Weather: cloudy Depth: 5 FT TP#1 0 lft Topsoil 1-4ft Damp, dark brown silty with cobbles 4-5ft Cobbles and fractured basalt Time Measurement(inches) Level Refilled To (inches) Rate(inches/hour) 8:30 12 8:31 0 12 8:32 0 12 8:33 0 — Site Infiltration Rate(inches/hour) 720in/hr Rapid Soil Sol lions INC 1 503-816-3689 mia@rapidsoilsolutions.com APPENDIX B(4) < 4B > Share Drive 6P Drywell ,. Subcat Reach 'on• Link 1 Routing Diagram for 0980-001 Baleine HydroCAD Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 4B: Shared Drive Runoff = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 8,095 98 impervious, dwy 8,095 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4B: Shared Drive Hydrograph 0.15 I i I i i I I •Runoff I I0.139cfs@7.58hrsI I 0.14�' y _ i I T 24-hr-- 0.13 I I I 0.12_' __�_ j 1-0-year RairyfarC=3: 0"= 0.11'" Runoff Area=8,095 sf 0.1��) Runoff Volume=2,002 cf 0.09 Runoff Depths=2.97" �° 0.07 � Tc=�5.0 m i n 0.06_ CN=0/98 0.05 0.04='' I' %' 0.03 ' 0.02_' 1 0.010�/ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Pond 6P: Drywell Inflow Area = 8,095 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf Outflow = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf, Atten= 0%, Lag= 0.9 min Discarded = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.99'@ 7.89 hrs Surf.Area= 22 sf Storage= 7 cf Plug-Flow detention time=0.9 min calculated for 2,002 cf(100% of inflow) Center-of-Mass det. time= 0.9 min ( 666.0 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.00' 17 cf 2.33'D x 4.00'H Drywell Inside#2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.00' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.00' 360.000 in/hr Exfiltration over Wetted area above 218.00' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.139 cfs @ 7.89 hrs HW=218.99' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.139 cfs @ 0.01 fps) Pond 6P: Drywell Hydrograph / ❑Inflow 0.15 0 Discarded 10.139 cfs%9hrs 1 Inflow Area=8,095 sf 0.1 LL 0.13 Peak Elev=218.99' 0.12 0.11= % Storage=7 cf '`- 0.08= ° 0.070.06 0.05 0.04= 0.03 0.02 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) Lo2 /2N=1 Planter Subcat Reach 'on. Link Routing Diagram for 0980-001 Baleine HydroCAD --N____ Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 2: Lot 2 Runoff = 0.018 cfs @ 7.90 hrs, Volume= 246 cf, Depth= 0.79" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr WQ Rainfall=1.00" Area (sf) CN Description * 3,728 98 roof impervious 3,728 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 2: Lot 2 Hydrograph 0.019= I ■Runoff 0.018= 10.018 cfs @ 7.90 hrs I 0.017 + T pelA24-hr- 0.015_ 1MIQ Rainfall=1 .00" 0.014 0.013 Runoff e Ara=3'1,728 sf-- �/ Runoff Vol-Lime=246 cf-- 0009_ r Runoff Depth=0.79" o 0.008_ / Tc=5 O-nin-- 0.007_ _ CN-OM98 0.005= / I I I 0.004= 'Z 0.003 0.002= 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Pond 2P: Planter Inflow Area = 3,728 sf,100.00% Impervious, Inflow Depth = 0.79" for WQ event Inflow = 0.018 cfs @ 7.90 hrs, Volume= 246 cf Outflow = 0.003 cfs @ 5.83 hrs, Volume= 246 cf, Atten= 83%, Lag= 0.0 min Primary = 0.003 cfs @ 5.83 hrs, Volume= 246 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 100.97' @ 13.36 hrs Surf.Area= 63 sf Storage= 61 cf Plug-Flow detention time=227.3 min calculated for 246 cf (100% of inflow) Center-of-Mass det. time= 227.2 min ( 939.7 - 712.5 ) Volume Invert Avail.Storage Storage Description #1 100.00' 76 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 100.00 63 0 0 101.20 63 76 76 Device Routing Invert Outlet Devices #1 Primary 100.00' 2.000 in/hr Exfiltration over Surface area #2 Primary 101.00' 6.0" Horiz. Orifice/Grate C= 0.620 Limited to weir flow at low heads Primary OutFlow Max=0.003 cfs @ 5.83 hrs HW=100.01' (Free Discharge) liii 1=Exfiltration (Exfiltration Controls 0.003 cfs) 2=Orifice/Grate ( Controls 0.000 cfs) 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 4 Pond 2P: Planter Hydrograph ❑Inflow 0.019- I0.018cfs. 7.90hrs I ❑Primary 0.018= Inflow Area=3,728 sf 0.017 0.016= Peak Elev=100.97' 0.015� 0.013_ Storage=61 cf 0.011 0 o.00s 0.008 0.007=0.006 0.005; // 0.005 , 0.003 cfs @ 5.83 hrs 0.003 0.001 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) Appendix C: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Z O NOTES: ,_ / H O 0 1. THE EXISTENCE AND LOCATION OF ANY UNDERGROUND UTILITIES ORLiJ \ / \ / \ \ / - W 00 ce STRUCTURES SHOWN ON THESE PLANS ARE OBTAINED BY A SEARCH / / ( G\ - / Q M O OF AVAILABLE RECORDS. TO THE BEST OF OUR KNOWLEDGE, THERE - ''�, ar� \ d U _ ARE NO EXISTING UTILITIES EXCEPT THOSE SHOWN ON THESE PLANS. G ,,��_"_7y THE CONTRACTOR IS REQUIRED TO TAKE DUE PRECAUTIONARY 1. I I I 004 / / I O MEASURES TO PROTECT THE UTILITY LINES SHOWN ON THESE\.��aS'►�� II G DRAWINGS. THE CONTRACTOR FURTHER ASSUMES ALL LIABILITY AND N +Nilj�,'�� W W w w / w \ w w wl W � I W r N W RESPONSIBILITY FOR THE UTILITY PIPES, CONDUITS OR STRUCTURES W' - \ BALEINEST \ /w / w w w wl w w \ w— > (/) C SHOWN OR NOT SHOWN ON THESE DRAWINGS. / / / / W (V O 2. INFILTRATION SYSTEM SHALL BE LOCATED A MINIMUM OF 10'FROM - _ / // .- a O O BUILDINGS AND A MINIMUM OF 5'FROM PROPERTY LINES AS \ / — - \ \ \ / U) Q (n W MEASURED FROM THE EDGE OF DRAIN ROCK / 1' �>/ — / _ — W b 3. BUILDING CRAWL SPACE DRAIN LINE TO BE DAYLIGHTED. - '�' I \\. Z_ X O J GI ..' —I- % 4 PROPOSED FLOW-THROUGH PLANTER BOX(64 SF) -10'PRIVATE STORM EASEMENT Q 4. ROOF DRAIN CONNECTION SHOWN IN APPROXIMATE LOCATION. I \ 4 I \ AA.- - FOR ROOF&DRIVEWAY DRAIN. SEE STANDARD W I— X Iy REFER TO ARCHITECTURAL PLANS FOR ACTUAL LOCATION. \ I / CITY OF LAKE OSW DETAIL SD9-12 I IIh — \ / / \ m < 0 G 1 } / _ I. 89 LF 4'ADS 0 2.0%MIN \ V SITE NOTES: 7 6.5' I i ALL DIMENSIONS AND SQUARE FOOTAGE ARE �� \ + \ i� / \ --- APPROXIMATE FIGURES. TA 8.5'G 1 —9.74' _, ,,,,_ _/____I ___s -2,4 i_ CONTRACTOR TO ENSURE DRIVEWAY SLOPE TO DRAIN 1 +� )q ,, I - I I � AWAY FROM THE PROPOSED GARAGE AND SHEET FLOW / 7j \ — /_____ . / m TO TRENCH DRAIN AS SHOWN 1 \ / ALL UTILITIES WILL BE INSTALLED UNDERGROUND 1 10 \ /. \1 = < G W CONTRACTOR IS TO PROVIDE A "HUB & TACK" SURVEY F � — / N ce PRIOR TO SCHEDULING A FOOTING INSPECTION CONNECINTOYROOF GROOF G 1 1 G o ° . ce I G I 1G G � (,) IG � G1 2 1 3 / 1✓7I. gill INLET PROTECTION 1 / 1. WATERPROOF (SEE NOTE 7) .-INCH / rc•`]' YYY111�/I!_! CONCRETE WALL / G`/j:.. PERFORATED PIPE FOR LAST iH OF FACILITY LENGTH. O F (SEE NOTE 6) O a WATERPROOF CONNECTION ly/ '•30-MIL LINER (SEE NOTE 3) O 0 / Z Lo N A (SEE NOTE 2) 4.1P TO APPROVED DISCHARGE POINT )D / - 0 1 G 2 O L - J i$ ii'� A. 1 w 1 _ L te a �� -��T�C�� H o R 1.5'MIN WIDTH FREEBOARD °. "' a 4 V �3'TO 6' a �_ a I .a \ N 0 G G 4. , z 1'�PONDING DEPTH ,,, •-MI I --- T, -- �: 2,2 / N LINE' MIN 1.5'SOIL MEDIA / ( I \\ / _ _ \ (5EE NOTE 8) Mil l-\�� I \��_�� ._uIV.�IU.�I�.A•raw -I-- \. �1�R,.� / v.� Irli (SEE NOTE 4) ✓�STORAGE LAYER. P_ •� ��' It_.'%�]' ��III / ��®�%/�L-��®r/� � � '�� I� � T \ -(5EE NOTES 5 h B) - - - },-+ y • � CQO�\�i ( � � � p( nor _ _ 1.. . . . . . . . `� I 17 E 1.5 ,AL :8 !��//�i!��/�y/�//�//�//�//�� , a w w, FOUNDATION DRAIN TOI APPROVED DISCHARGE `\ a / 'I I - m m~LL I: SECTION A-A I \ G 1. OVERFLOW ELEVATION MUST BE LOWER THAN INLET.SEPARATION FROM INLETS MUST BE MAXIMIZED. / - L1 DW \ OVERFLOW MUST S A BEEHIVE GRATE(SEE SD8-01 OR SDBF THE 1��V��1 IM�r lM�r 1��(�l��l IM2I II\�� I �I II\\ ` I/ �` r Q 2. LINER MUST BE INSTALLED ON ALL SIDES AND THE BOTTOM OF TXE PLANTER. J C_I Li Li ZJ LJ LJM �),1: LJ L� �/ 3. ALL PIPE PENETRATIONS INTO AND OUT OF THE PLANTER MUST BE WATERPROOF. _ _ _ _ ,t \ 4. 3-INCH CHOKER COURSE OF ROCK 'TO ' MUST COMPLY WITH ODOT SPECIFICATION 00430.11 S. STORAGE LAYER ROCK(1-)5"-N'MUST COMPLY WITH AASHTO/4.DEPTH 2'. 6. PERFORATED PIPE MUST COMPLY WITH DETAIL SD9-11. .'.' '.-.-.' ' '.-.-.'.'.-.-.-.'.'.-.%`.'.`.'.'.'.'.'.'.-.'.'.'.'.'.'.`.'.'.'.'.'.'.'.'.'.'.'.'.'.' .'.'.'.'.'.'.'.'.-.-. [ � / \ )�'jsy 7. INLET PROTECTION MUST BE CONCRETE PAD INSET 4'OR CLEAN CRUSHED ROCK�'-)4')THAT --- --- ---- -� - --- - - - - - - - - - - - - - - - - - - - - - _ - - , I I S COMPLIES WITH ODOT SPECIFICATION 00430.11 IS INSET 6 INCHES,AND IS UNDERLAIN WITH HIGH - "' '-'-"— \ ''" 0 DENSITY JUTE OR COCONUT COIR MATTING.MIN LENGTH AND WIDTH OF 1.5'. - 11\.� IL I / B. PRESCRIPTIVELY SIZED FACIUTIES MUST USE:1-FT PONDING DEPTH.1.5'SOIL MEDIA.AND 1-FT STORAGE LAYER. \ 'a /� / \ a DRAWING ADAPTED FROM CLEAN WATER SERVICES 15868 KIMBALL ST I(/\` s' CityoTLakeOswego FLOW THROUGH PLANTER TAX LOT 2901 \ 1± �D� E. \ ill.. Hogi�nringDivision SD9-12 I� / \ 1 YYY l.. ///��JJJ o e 'v EFFECTIVE DATE:SEPTEMBER 19,2020 NOT TO SCALE DRAWING NUMBERlil 'a' 4. 4 //� I / \I A7 i \. .c SHEET / m 10' 0 5' 10' 20' A o 1 OF SCALE: 1" = 10' Z m 0 4 C EMERIO ENGINEERING•SURVEYING• DESIGN Drainage Report Lot 3 of 5 Lot Subdivision at Tax Map 2S1E 07CA Tax Lot 100, 2902, 3000 Lake Oswego, Oregon Emerio Project Number: 0980-001 City of Lake Oswego Permit Numbers: LU 23-0002 Date: 12/23/2022 Rev 1: 09/14/2023 p PRO � F \��G � N EF `� O 81153PE E.87 DocuSigned by: A sy�gv . r EXPIRES: 12/31/2023 Prepared For: Prepared By: Kelly McCall Joshua Ayers, PE Renaissance Homes Emerio Design, LLC 16771 Boones Ferry Road 6445 SW Fallbrook PI, Suite 100 Lake Oswego, Oregon 97035 Beaverton, Oregon 97008 kmccall@renaissance-homes.com joshua@emeriodesign.com (503) 746-8812 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Table of Contents: APPENDIX A (1) Vicinity Map APPENDIX B (1) Soil Classification Map-"Soils Survey for Clackamas County" (2) Curve Number Table (3) Infiltration Tests (Rapid Soil Solutions, July 8, 2021 and May 18, 2022) (4) HydroCAD Plot APPENDIX C (1) Site Map (2) Flow-Through Planter Detail 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Project Overview and Description The project site is located on the south side of SW Baleine Street between the southeast corner of the intersection of SW Kimball Street & Baleine Street and the southwest corner of the intersection of Inverurie Road. The existing condition is a large undeveloped lot. Five lots will be created with a new single-family home and attached garage on each lot. All new impervious area to be created by this project on this lot will be directed to new onsite stormwater systems. This report addresses the stormwater management for Lot 3 and includes the analysis of the shared driveway. Refer to Appendix C(1) for site map. The property is zoned R-7.5 (Residential, 7,500 SF lots) with a lot size of 13,025 SF. The proposed project will address the following elements of the Lake Oswego Stormwater Management Manual: Site Assessment and Feasibility Analysis, Onsite Stormwater Management, and Design for Water Quality. Site Assessment and Feasibility Analysis: The proposed site is composed of Salem silt loam, hydrologic soil group B. Preliminary investigation by Rapid Soil Solutions on July 8, 2021, measured infiltration rates of 3 in/hr at 8 feet below ground surface. At a test pit closer to the shared driveway and southern lots 4 and 5 of the development, infiltration testing was performed on May 11, 2022, and yielded a measured rate of 720 in/hr at 5 feet below ground surface. During field exploration groundwater was not encountered in test pits; however, Portland area groundwater mapping shows groundwater to be approximately 40 feet below ground surface. Onsite stormwater management is proposed for this site. Onsite Stormwater Management — Shared Driveway: To achieve onsite stormwater management for the shared driveway, a drywell system located in an easement on Lot 4 is proposed to infiltrate 100% of the driveway runoff during the 10-year 24-hour design storm. A lynch style catch basin with an 18-inch sump will provide pretreatment prior to the DEQ defined UIC (drywell). Reference drywell system dimensions and modeling data below. Input Data: Impervious Area: 8,095 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.00 Feet Drywell Bottom Elevation: 219.00 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.0 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.14 CFS Peak Flow Rate in Infiltration Device: 0.14 CFS Peak Water Surface Elevation: 218.99' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 5' below finish grade. Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. Design for Water Quality — Lot 3: Water quality will be addressed for Lot 3 by routing all impervious areas to a flow- through planter box. The layer of growing medium (soil) within the planter will act as an orifice, limiting the flow of water as it infiltrates through this amended soil layer at a rate of 2.0 in/hr before collecting in an underdrain within a 12" rock layer. Per discussion with staff, flows will exit the planter box through 4" pipe and discharge onsite to the delineated wetland area to the east. Flow-Through Planter Analysis: The flow-through planter was modeled using HydroCAD V10.0 Stormwater Modeling Software. This analysis appears in Appendix B(4). The water quality design storm used in modeling has a depth of 1 inch over 24 hours in a Type 1A distribution. Reference planter dimensions and modeling data below. Input Data: Impervious Area: 3,653 SF Curve Number: 98 Time of Concentration: 5 Minutes Planter Surface Area: 62 SF Freeboard: 2" Minimum Storage Depth: 12" Topsoil Media Depth: 18" Amended Soil Infiltration Rate: 2.0 Inches/Hour Drain Rock Layer Thickness: 12" Drain Rock Void Ratio: 33% Design Storm: Type 1A, 10-year Design Storm Depth: 1 Inch in 24-hours 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Output Data: Peak Flow Rate from Impervious Area: 0.017 CFS Peak Flow Rate in Infiltration Device: 0.003 CFS As shown above, the planter is sized to meet water quality requirements for this project. Sizing was iterated to keep the peak water elevation just under the overflow outlet. Overflow Discharge: In the event of flows greater than the WQ capacity of the flow-through planter system, flows will reach the overflow outlet set 12" above the planter surface and be conveyed by pipe through and easement across Lot 3 and discharge to wetland. Engineering Conclusions Based on the results of this analysis, the proposed stormwater system meets the 2020 City of Lake Oswego Stormwater Management Manual standards. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Appendix A: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix A(1) Vicinity Map I \ L \ • ..I 1.�..._.._ ✓ ✓ ,`\Mtl 4•. _I l.il ...I. F'tI RMII.0.il .Iri 1, L, it Ai,-v4.., rl . - /',,,khan Sl,a �••�. _ nl SITE f,r,,nl K r-a., h I _ P.��p13121 f^I :^;,,kill,, Village _ '. .:ti ShaA..s ( i i- Palls-Ea;l Mentesaorl 1-n yearn S 1 °5 Lake Wove I L yl� Iluga n Rc a racy'm., Elementary • • ,'�'I sl `,•`�I"n;,.._� �,1.-;'�r.l t School I _ _l -_��) W Dods ,P • � 0' t-. f L� ePt 1 ..--4... 2 JI y,a ,, yy.. �!akadye= . T'_" I-fv'C".�'r'^• ti+`'✓ 0e P0_:�.` I C �: R Lakr, .I eye 1 ` l.'`? 1 FIIWnGA r.. i fW - \ll �. hl 'l FIIW ollaulfj.ra(? a j v \ 0 - II j. :6w Manrnna I } f. _fit f "G. i rr•®Rd Prp�" \eel o}�..� i, �` ' i i 4 j a j l I; - —3 �• C If k4 b i Ll j1'- .,rh or Pam' .II—ll. .l Pt. i 12 J I 4 Lamont ypnrev. 1 -..L f 1 '' ''very„ Natural Ar, Vilest PS \'\ \e ^, •I Ii Sam i;\ i ' _ p1'Ts '.7 Chapman W.lv ea /�c L: .�••.y��]ste � ri'r,.e✓, Y. rIFa bi r' r. Q \ ,y� wJ - roY i Cobb Way -nna rid I j I QW ey ..Vddw je , ''' Wler1 SI The Children, _ Z j t1 en St [� I Him Ararkeny in wlllo %1'•. L I )ace Fr�'st CI ', U I _ f N c.t o J r t -L7 I �f `!�\ ., .LJeL� s 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix B(1) Soil Classification Map � � •�. ~ ,f � � * t r.ft. iiic.. • - .14?fie t`� Y i '{4, . at - iiiP - ��y�pf�t� �t ,y, 'ILL' �-+ri' . .rr•�6�� ..� �/��pty �/ � � ,o ` f . r 1f► 7 .4.1'.try I e 01 .Y..'f .. isr.3JlA • +}" , • -Z! k,: s ,yv. "'.. 1 kiy, -*4 tir kAt-,. r.# 4,-- IV: .i. •,,,.., . . ...iffr" j or kit r. ' O. +l'}�fky iii, al r a, 4 •l•� ...AC.." .d,rt Tables nom..Soil Group Summary es Map[tail 0 Summary by Map Unit—Clackamas County Area,Oregon(O11610) Summary by Map Unit—Clackamas County Area,Oregon(OR610) 4 Map unit symbol Map unit name Resins Acres in Am Percent of AOI 25 Cove silty clay loam D 0.7 31.5% 76B Salem silt loam,0 to 7 percent slopes B 1.4 68.5% Totals for Area of Interest 2.1 100.00/0 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B(2) Curve Number Table RUNOFF CURVE NUMBERS (TR55) Table 2-2a: Runoff curve numbers for urban areas RUNOFF CURVE NUMBERS (TR55) _ Table 2-2a: Runoff curve numbers for urban areas 1 Cover description CN for hydrologic soil group Average percent impervious Cover type and hydrologic condition area2 A B C D Fully developed urban areas (vegetation Use CN = 89 for Cove silty established) clay loam — Open space (lawns, parks, golf courses, cemeteries, etc.) 3: Poor condition (grass cover <50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover >75%) 39 1 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding Use CN = 79 for Salem silt - right-of-way) loam Paved; open ditches (including right-of-way) 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: _ Natural desert landscaping (pervious areas only) 4 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: _ Commercial and business 85 89 92 94 95 _ Industrial 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 6445 SWFallbrook Place,Suite too • Beaverton,OR 97008 • emeriodesign.com Matt Boggs Project Manager New Look Development E—Matt@NewLookDev.com P—(503)577-2646 8 July 2021 Re: Infiltration testing at empty lot next to 15868 SW Kimball Street, Lake Oswego OR Field Investigation: Rapid Soil Solutions (RSS) has attempted to performed one (1) infiltration tests. Figure 1 below shows the project site location. Soils found on site match those in by DOGMI. RSS found dry stiff fine-grained soils SW Baleine St 1— cn rn 15811 15825 15879 15868 Figure 1 Infiltration Testing: RSS performed the testing as per the City of Lake Oswego storm water manual. RSS shows on our infiltration sheet the pre-soak and testing. RSS found the rate to be 3in/hr. Groundwater Based upon the Portland area ground water map it is 40ft below the site. fix. ,l ? 7 .? USGS 5098 The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, I ‘rp PROic r G�N�F,Qs�O ' 19744 PE i2 •REGON 1/(Y15, 94\ -� ��1 C. MPN4' EXPIRES: 3 /-!di Z Mia Mahedy, PE GE. Rapid SoiloI irtions IIIC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results - — 1 4 ', t•• - « - . , HA#1 'er f‘. v... J . IL 111. . . -"47 . •Aii: ...._4:3 4 .Ilt N `i Preliminary Information SW Kimball St,Lake Performed By: Location: Oswego, OR; east of (Supervised by Mia Olenka Duncan 15868 SW Kimball St Mahedy,PE,GE) Date&Time: 7/6/21 at 12:30 Gm Instrument Used: Hand au:er Weather: 80°,mostly sunny Depth: 8 ft HA#1 A 4 hour presoak was started at 8:30 am with 16"of water. All 16"had drained at the end of the presoak, and the test was be_un at 12:30 .m. Soil Profile Detail Depth(ft) Description 0-1' Topsoil 1-3' Barely damp medium brown clayey silt 3-3.5' Coarse gravel with fine grained clay/silts 3.5-8' Barely damp beige clay Time Measurement(inches) Level Refilled To(inches) Rate (inches/hour) 12:30 - 16 - 1 10.75 - 10.5 1:30 8.5 12.5 4.5 2 10.5 13 4 2:30 11 - 4 3 6.25 11.5 9.5 3:30 10 - 3 Site Infiltration Rate(inches/hour) 3 Rapid I SoilSolOtions INC 503-816-3689 I mia@rapidsoilsolutions.com Matt Boggs Project Manager New Look Development 7685 SW Cirrus Dr. 32F Beaverton, Oregon 97008 E—Matt@NewLookDev.com P—(503)577-2646 18 May 2022 Re: Infiltration testing for Kimball Street, Lake Oswego, OR Dear Mr. Boggs, Field Investigation: Rapid Soil Solutions (RSS) has performed a total of one (1) infiltration test. The figure below shows the site RSS found a mixture of fine-grained Missoula Flood Deposits, Off and fractured basalt. Testing was performed for future storm water design. Location shown below. o0 al, 15811 46 1 15825 $8 15879 - _ 15868 15921 Ael,, r Infiltration Testing and ground water Infiltration testing was performed as per the Lake Oswego Storm Water Manual 2018. The first hole was a test pit as the south side of the lot is fractured basalt and cobbles on 11 May 2022. The test was performed between proposed lots 4/5 and the rate was 720in/hr. See attached soils logs. Additional test holes were excavated between lots 1 and 2 and then on lot 3. Fine grained soils were found with the excavator. We returned on 13 May 2022 to hand excavate those holes using a hand augur for a better pre-soak and readings. RSS found the soils to be hard white elastic CLAY and when we excvated to a depth of 4ft and performed the four(4) hour pre-soak they did not drain at all. Ground water Based upon the USGS groundwater is within 40ft of the site. v.. urham1 I i-r USGS 2008-5059 Rapid I I So i L S o`w t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Test hole locations for lots 1-3 =• - Did not drain at all during FA ...,� e=-e� � ,, ` "m— ' .", . the pre-soak phase Q` _ e• - e e-- 4.#-=_ _ ' - .-eB�- a-- [ ; - —e 6 .- e. e. ®-- -- 0 0i= e, R �1 Q: HA#2, `.sue t1 e $. a =_ A; / ©j._bt - q - -, T.s • -; a _ . a. a-- a!-: 1 o �- _ ©-, e- , . -_r - ,,-.e. e- TI.. maw..*In --Conclusion RSS recommends onsite infiltration for lots 4 and 5. With lots 1-3 drainage being piped to storm water basin that is set aside on lot 4. The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, CEO PR0FF 4, Sol cr 19 44P O. 7•REGON ,- '1 GAY15 ` • 1 �41 C. MAN EXPIRES: /t- 2), /- Zdi 2_ Mia Mahedy, PE GE Rapid I I S o i L S o`V t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results .�, • {,-- .._ - .N N$7 .-. �� ,— i se- 5 S _ - �� .. -V -i .s.. vfva TL ua � _ Or- •- ,i-.. 0oit - - it so n - -, . a- °r ._ I-I .a. -- - - Preliminary Information Performed By: Location: Kimball Street (Supervised by Mia Rick Sands Mahedy, PE,GE) Date& Time: 5-11-22, 830 am Instrument Used: excavator Weather: cloudy Depth: 5 FT TP#1 0 lft Topsoil 1-4ft Damp, dark brown silty with cobbles 4-5ft Cobbles and fractured basalt Time Measurement(inches) Level Refilled To (inches) Rate(inches/hour) 8:30 12 8:31 0 12 8:32 0 12 8:33 0 — Site Infiltration Rate(inches/hour) 720in/hr Rapid Soil Sol lions INC 1 503-816-3689 mia@rapidsoilsolutions.com < 4B > Share Drive 6P Drywell ,. Subcat Reach 'on• Link 1 Routing Diagram for 0980-001 Baleine HydroCAD Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 4B: Shared Drive Runoff = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 8,095 98 impervious, dwy 8,095 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4B: Shared Drive Hydrograph 0.15 I i I i i I I •Runoff I I0.139cfs@7.58hrsI I 0.14�' y _ i I T 24-hr-- 0.13 I I I 0.12_' __�_ j 1-0-year RairyfarC=3: 0"= 0.11'" Runoff Area=8,095 sf 0.1��) Runoff Volume=2,002 cf 0.09 Runoff Depths=2.97" �° 0.07 � Tc=�5.0 m i n 0.06_ CN=0/98 0.05 0.04='' I' %' 0.03 ' 0.02_' 1 0.010�/ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Pond 6P: Drywell Inflow Area = 8,095 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf Outflow = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf, Atten= 0%, Lag= 0.9 min Discarded = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.99'@ 7.89 hrs Surf.Area= 22 sf Storage= 7 cf Plug-Flow detention time=0.9 min calculated for 2,002 cf(100% of inflow) Center-of-Mass det. time= 0.9 min ( 666.0 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.00' 17 cf 2.33'D x 4.00'H Drywell Inside#2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.00' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.00' 360.000 in/hr Exfiltration over Wetted area above 218.00' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.139 cfs @ 7.89 hrs HW=218.99' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.139 cfs @ 0.01 fps) Pond 6P: Drywell Hydrograph / ❑Inflow 0.15 0 Discarded 10.139 cfs%9hrs 1 Inflow Area=8,095 sf 0.1 LL 0.13 Peak Elev=218.99' 0.12 0.11= % Storage=7 cf '`- 0.08= ° 0.070.06 0.05 0.04= 0.03 0.02 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) Lo3 AN=1 Planter Subcat Reach 'on. Link Routing Diagram for 0980-001 Baleine HydroCAD --N____ Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 3: Lot 3 Runoff = 0.017 cfs @ 7.90 hrs, Volume= 241 cf, Depth= 0.79" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr WQ Rainfall=1.00" Area (sf) CN Description 3,653 98 roof impervious 3,653 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3: Lot 3 Hydrograph 0.019- I I •Runoff 0.018 _ I o.o17 cfs @ z90 hrs 0.017 , type IA 24-h r 0.016 - n 0.015; _ YYQa RajOaI1=.1 X „ 0.014 0.013 Runoff-Ara=_3,653-sf-- _ 0.012= _ 0.011 RunofVoFume=241 cf 0..01 Runoff depth=0.79"-- 0.008= 0/ Tc=5.0 min 0.007 0.006 CN=0/98-- 0.005 0.004 0.003 0.002 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Pond 3P: Planter Inflow Area = 3,653 sf,100.00% Impervious, Inflow Depth = 0.79" for WQ event Inflow = 0.017 cfs @ 7.90 hrs, Volume= 241 cf Outflow = 0.003 cfs @ 5.85 hrs, Volume= 241 cf, Atten= 83%, Lag= 0.0 min Primary = 0.003 cfs @ 5.85 hrs, Volume= 241 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 100.96' @ 13.33 hrs Surf.Area= 62 sf Storage= 60 cf Plug-Flow detention time=224.7 min calculated for 241 cf (100% of inflow) Center-of-Mass det. time= 224.7 min ( 937.2 - 712.5 ) Volume Invert Avail.Storage Storage Description #1 100.00' 74 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 100.00 62 0 0 101.20 62 74 74 Device Routing Invert Outlet Devices #1 Primary 100.00' 2.000 in/hr Exfiltration over Surface area #2 Primary 101.00' 6.0" Horiz. Orifice/Grate C= 0.620 Limited to weir flow at low heads Primary OutFlow Max=0.003 cfs @ 5.85 hrs HW=100.01' (Free Discharge) liii 1=Exfiltration (Exfiltration Controls 0.003 cfs) 2=Orifice/Grate ( Controls 0.000 cfs) 0980-001 Baleine HydroCAD Type IA 24-hr WQ Rainfall=1.00" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 4 Pond 3P: Planter Hydrograph ❑Inflow 0.019=' - o.on ds. zeo nrsl ❑Primary 0018 Inflow Area=3,653 sf 0.017=' 0016 Peak Elev=100.96' 0.015- _ Storage=60 cf 0.013 o 0.005 /A11'_ / i 0.003 0.003 ors @ 5.35 nrs 0.002=' 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) Appendix C: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com G \ \ i_ 0 NOTES: W w w w wy w w w w w •v� w w w w /,;v Z p W 3. THE EXISTENCE AND LOCATION OF ANY UNDERGROUND UTILITIES OR \ - 0 \ �� • / • • / \ / W O re STRUCTURES SHOWN ON THESE PLANS ARE OBTAINED BY A SEARCH // \ • \ \ \ • / 5 < M 0 OF AVAILABLE RECORDS. TO THE BEST OF OUR KNOWLEDGE, THERE \ \ - BALEINEST / i \ / \ / d t� ARE NO EXISTING UTILITIES EXCEPT THOSE SHOWN ON THESE PLANS. —• \ \ ti N THE CONTRACTOR IS REQUIRED TO TAKE DUE PRECAUTIONARY / - — — .- 0 O MEASURES TO PROTECT THE UTILITY LINES SHOWN ON THESE i DRAWINGS. THE CONTRACTOR FURTHER ASSUMES ALL LIABILITY AND I PROPOSED FLOW-THROUGH PLANTER BOX(64 SF) \ -10'PRIVATE STORM EASEMENT %- \ \ W N W RESPONSIBILITY FOR THE UTILITY PIPES, CONDUITS OR STRUCTURES FOR ROOF&DRIVEWAY DRAIN. SEE STANDARD / • • > COI- C • SHOWN OR NOT SHOWN ON THESE DRAWINGS. - CITY OF LAKE OSWEGO DETAIL SD9-12 11 / - \ - \ \ 0 N O N 2. INFILTRATION SYSTEM SHALL BE LOCATED A MINIMUM OF 10'FROM / /- � / — \ / \ / / G - / I_ I- d O O BUILDINGS AND A MINIMUM OF 5'FROM PROPERTY LINES AS 7 - } / \ � y/. \ U a WMEASURED FROM THE EDGE OF DRAIN ROCK / 6— + I I �.1 1�` \ 1 \• 89 LF 4"ADS®209,MIN \\\ I \ Z J J 3. BUILDING CRAWL SPACE DRAIN LINE TO BE DAYLIGHTED. \ \ i • / �( _ _ 9.74' / a 4. ROOF DRAIN CONNECTION SHOWN IN APPROXIMATE LOCATION. gg '� 19 I -----�cl — . ..- /\ - \ \ LLI \ 7. \. J I- �C LL 0 REFER TO ARCHITECTURAL PLANS FOR ACTUAL LOCATION. Y — I v /� / limd. v • N � � SITE NOTES: ` \ U ALL DIMENSIONS AND SQUARE FOOTAGE ARE �} \ / ` \ _ . \ \\ APPROXIMATE FIGURES. _ _ G CONTRACTOR TO ENSURE DRIVEWAY SLOPE TO DRAIN ` CONNECT TO ROOF G i— AWAY FROM THE PROPOSED GARAGE AND SHEET FLOW m TO TRENCH DRAIN AS SHOWN DRAIN SYSTEM ALL UTILITIES WILL BE INSTALLED UNDERGROUND 0 �IF1 21 \ X CONTRACTOR IS TO PROVIDE A "HUB & I \ \ WTACK" SURVEY M ce PRIOR TO SCHEDULING A FOOTING INSPECTION •7 W CONNECT TO ROOF 9' " - - ...., i.. DRAIN SYSTEM O Q . . . J G G GG 2 ..._ ---- 3 / PROPOSED FLOW-THROUGH PLANTER BOX(74 SF) c / FOR ROOF&DRIVEWAY DRAIN. SEE STANDARDCe / CITY OF LAKE OSWEGO DETAIL SD9-12 O I I G iNow u) '71/-� INLET PROTECTION O O / Z WATERPROOF (SEE NOTE 7) .CONNECTION �- �-INCH IG G k III III CONCRETE WALL % 'C:. PERFORATED PIPE FOR LAST \ OF FACILITY LENGTH. F (SEE NOTE 6) 7 L a F 0000 00 �o�U 1n WATERPROOF CONNECTIONL. 1n allSEE NOTE 3 ..�� 30-MIL LINER ( ) -I (�� 1��r O_ o TO APPROVED DISCHARGE POINT A I (SEE NOTE 2) �V ' i a V7 L : • 1►r � A • Ian a J — G A f G _,L,,:, N„. .. uu ,,1 \t L, \., ,\,,,)„, ,LL,Li \ .: , Is.-1.5'MIN WIDTH .,..L ,L FREEBOARD •� G \ . ,,, 40 G G s.: T'1'PONDING DEPTH \ CiLINE• MIN 1.5SOIL MEDIA / G � O(SEE NOTE8) .--- /,' 40 ` SEE NOTE 4) (S - I _ ' 1 I III • II I- STORAGE LAYER. I cl m 4 \ I II II II (SEE NOTES 5 3 8) cl c �i � .. i 4 , 0 � • •'� • •. ��/��. Uwe �Uw ---� a: 7 wl 7:8 4; ,v,/,/\/\/\/\/\/v\•,..„,,,,,,, _._•.,... -__.. .2:_-___...L.L...._-_ .2.;_,-__•.2..,..--. 0 1 I G G 41. OUN'ATION DRAIN SECTION /L /L TO APPROVED DISCHARGE • /y NOTES: SEI.I AQIY A-A POINT \a a ( \ / \ mo I. OVERFLOW ELEVATION MUST BE LOWER THAN INLET.SEPARATION FROM INLETS MUST BE MAXIMIZED. \ \\./\�— �'a--. 1—\� \ uA OVERFLOW MUST BE A BEEHIVE GRATE(SEE SD8-01 OR SDB-02). J1 / \ 2. LINER MUST BE INSTALLED ON ALL SIDES AND THE BOTTOM OF THE PLANTER. J�3. ALL PIPE PENETRATIONS INTO AND OUT OF THE PLANTER MUST BE WATERPROOF. J . ,)C G 4. 3-INCH CHOKER COURSE OF ROCK('TO 34")MUST COMPLY WITH ODOT SPECIFICATION 00430.11 \ - 5. STORAGE LAYER ROCK(14"-W")MUST COMPLY WITH AASHTO#4.DEPTH 2'. Ia - a- . ��I / \\ S 6. PERFORATED PIPE MUST COMPLY WITH DETAIL SD9-11. /� V 7. INLET PROTECTION MUST BE CONCRETE PAD INSET 4"OR CLEAN CRUSHED ROCK(3"-IS")THAT \ ° -D Y'i COMPLIES WITH ODOT SPECIFICATION 00430.11 IS INSET 6 INCHES,AND IS UNDERLAIN WITH HIGH a DENSITY JUTE OR COCONUT COIR MATTING.MIN LENGTH AND WIDTH OF 1.5'. N]O) -- - \ \ B. PRESCRIPTIVELY SIZED FACILITIES MUST USE: 1-FT PONDING DEPTH, 1.5'SOIL MEDIA,AND 1-FT �H \\ a G y SADAPTE LAROR. \a �' \ TAX LOT 200 0DRAWING ADAPTED FROM CLEAN WATER SERVICES I \ \ I / - \ 1 a. City of Lake Oswego FLOW THROUGH PLANTER SD9-12 �ry� lO 4 ' \ PA Engineering Division^on J EFFECTIVE DATE:SEPTEMBER 14,2020 NOT TO SCALE DRAWING NUMBER SHEET m 10' 0 5' 10' 20' A 7„/ o 1 I SCALE: 1" = 10' /OF m 0 4 EMERIO ENGINEERING•SURVEYING• DESIGN Drainage Report Lot 4 of 5 Lot Subdivision at Tax Map 2S1E 07CA Tax Lot 100, 2902, 3000 Lake Oswego, Oregon Emerio Project Number: 0980-001 City of Lake Oswego Permit Numbers: LU 23-0002 Date: 12/23/2022 Rev 1: 09/14/2023 PROFFs�i 81153PE r ,—DocuSigned by: REG(�N� f— EXPIRES: 12/31/2023 Prepared For: Prepared By: Kelly McCall Joshua Ayers, PE Renaissance Homes Emerio Design, LLC 16771 Boones Ferry Road 6445 SW Fallbrook PI, Suite 100 Lake Oswego, Oregon 97035 Beaverton, Oregon 97008 kmccall@renaissance-homes.com joshua@emeriodesign.com (503) 746-8812 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Table of Contents: APPENDIX A (1) Vicinity Map APPENDIX B (1) Soil Classification Map-"Soils Survey for Clackamas County" (2) Curve Number Table (3) Infiltration Tests (Rapid Soil Solutions, July 8, 2021 and May 18, 2022) (4) HydroCAD Plot APPENDIX C (1) Site Map 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Project Overview and Description The project site is located on the south side of SW Baleine Street between the southeast corner of the intersection of SW Kimball Street & Baleine Street and the southwest corner of the intersection of Inverurie Road. The existing condition is a large undeveloped lot. Five lots will be created with a new single-family home and attached garage on each lot. All new impervious area to be created by this project on this lot will be directed to new onsite stormwater systems. This report addresses the stormwater management for Lot 4 and includes the analysis of the shared driveway. Refer to Appendix C(1) for site map. The property is zoned R-7.5 (Residential, 7,500 SF lots) with a lot size of 13,550 SF. The proposed project will address the following elements of the Lake Oswego Stormwater Management Manual: Site Assessment and Feasibility Analysis, and Onsite Stormwater Management. Site Assessment and Feasibility Analysis: The proposed site is composed of Salem silt loam, hydrologic soil group B. Preliminary investigation by Rapid Soil Solutions on July 8, 2021, measured infiltration rates of 3 in/hr at 8 feet below ground surface. At a test pit closer to the shared driveway and southern lots 4 and 5 of the development, infiltration testing was performed on May 11, 2022, and yielded a measured rate of 720 in/hr at 5 feet below ground surface. During field exploration groundwater was not encountered in test pits; however, Portland area groundwater mapping shows groundwater to be approximately 40 feet below ground surface. Onsite stormwater management is proposed for this site. Onsite Stormwater Management: Both the shared driveway and the onsite Lot 4 impervious areas will achieve onsite stormwater management by the same methodology: a drywell system is proposed to infiltrate 100% of the driveway runoff during the 10-year 24-hour design storm. A lynch style catch basin with an 18-inch sump will provide pretreatment prior to the DEQ defined UIC (drywell). The shared driveway system will be installed in an easement on Lot 4. Reference drywell system dimensions and modeling data below. Shared Driveway Analysis Input Data: Impervious Area: 8,095 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.00 Feet Drywell Bottom Elevation: 219.00 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.0 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Infiltration Rate Factor of Safety: 2 Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.14 CFS Peak Flow Rate in Infiltration Device: 0.14 CFS Peak Water Surface Elevation: 218.99' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 5' below finish grade. Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. Lot 4 Areas Analysis Input Data: Impervious Area: 5,080 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.50 Feet Drywell Bottom Elevation: 219.50 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.50 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.087 CFS Peak Flow Rate in Infiltration Device: 0.087 CFS Peak Water Surface Elevation: 219.74' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 4.76' below finish grade. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at the downspout connections or catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. UIC Review with Oregon DEQ: This project will use a UIC system that receives runoff from residential driveway areas for the onsite Lot 4 system as well as the shared driveway system; therefore, registration and approval with DEQ is required under Authorization by Rule requirements. Pretreatment of the driveway areas is satisfied by providing the minimum required 18 inches of sump below the snout in a silt trapped basin. Engineering Conclusions Based on the results of this analysis, the proposed stormwater system meets the 2020 City of Lake Oswego Stormwater Management Manual standards. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Appendix A: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix A(1) Vicinity Map - ' 1 t. -. ia.�[ifSllYStd]Spfin�.RJ..._.I \ L \ ..I I.r..._.._ ✓/ ✓ ,\Mfl4 _11.1�.....� ...�. F,,,,,,II.tI^.II I .�^_._.._ SrV I�r11.iIJ it _ ..U,CCC'', ` _ y 'll•. "' P.* .ni I Ai. f�J.., rl t - ra,kha: SIB �..i. ry � r. If n1 SITE W 1,6 r•1 K Lae .... I _ P.j1p13121 P1 :^�aknJa Village '. F;TA-61;1 Mt:Metter, I n Sh.1A..sV•.r.. �; Lyle Wove A11r,J n Rc VV, nl JS1c� �,,Elean Wry 5t .Cra t Schod (( _ 1 W rods 'I � O` _ _ w�tt`eit ..-. \�` -\.µ a (+r Mye ; i2d e Lakrt` ` 'r l �t.J,,h oSe +, I .1`e rc . l I i r. r I �,-� ` a. tr IV f lw oA L ? Flrwdf .�. r,d' - - 1 it I w M.-taro., I ,, t _3r ,r a. i rr,Raa 1�eero}�•i ,, �= 1 P - 1 F i - n 1 rp Af. t• .r•. ` F C b�i " 1I'- .,rh ct Pam' .I�—ll. : .l . Pr. i t 2 j I 4 rt Lamold Spnlr, 1 -..L 1 "''' err„ Naheal AP, Vilest P� r / tvi o,. �r,,li�r,.1 W.., r _ v v '�7 Chapman War Ga /�c L: .�•.\��]Ito � ri'r,.e✓, Y. rIFt bo �t r' Q \ ,y� wJ• - rcY i Cobb Way -N I I Pia /! .I QW ey yVddw�x,d SI z , \v> Wren: Si • Tile Chlldrens _ ZI - Haven Sr [�— r Nqu1 A,a(bnly in W1110 41 1 l+ee Fiyetl CI , U I f N c.t o J r t �-L7 :� � I �f-_ `! //.,�.LJeL� �s 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix B(1) Soil Classification Map .„,f 1414 F.W`: ;.1,:k ,V714: •• ' ''' r:„ .,•14 -- : -Z. -.0(: ':. 4 '-`'.`mv-A -4. •4,,,,I. „k,.. .44b.; .. - .', A-;-„,• . P.- -... .-t- .. • "• - . -s- - , . .. . . :.,.. . ,.._1.4, A A.. . . . 4 ... 4. t a ...ASISIESIIIIMUMINI NC: 11.1111'.1.14.1.1.1"11 11.-4-•.:444 Zt.' i o 4.,,. :•7.114( .40. 4,, , . vr-.?..•.... 1 ea 1 t...ori,till 4' .. .,..i* , t . •., 4. ,..-, ' ...4t ...,, ..,_, i, r ----- - - , •• 0 t•- •941' • . t• , 1 . • 4f...•;...rt s 1- t•*e .; ....i. . . 41 . 0.. • '•• ; „--"*. . .' • '4,4:-‘774,:. 7 . ,j, "4r .:,,. - ,. • , „ ,., T.', Vt.- .:•v,• c,,,t'''.."-44,Ati: t• :I.,7' . 4..A ittl''%',•.i.--, ,,4 - - w- 42i. .i. ._.-..._.,.. ..• ir, . , . 4it.l 1.• •.!.41.. . . •, •il.. ;•* j, :.rlas ....1 -'' . 't.•70. 'c- v•' , . • • ' . ‘' • ' .,..A. .4::. .'•• ' Q4.kler ,isk "tt, • ,.... ., ' If., 41 —_ _ " . . • ' 9.1 ., . ... ,.. If" . ' 4111114 lir • .4 t °io' •"kirfr ft\• ' i. 1 ,•.. A • -'1V f •• ". • I:. ki:. ' il*.`t,, • .: 011111r-.4 ' \ . ' i • ' ilL4 •=1 ===ii. - .,_ i ...se..," .A. table, Itydraloon Soil Group—Summary By map Iiint (,, Summary by Map Unit—Clackamas County Area,Oregon(OR610) Summary by Map Unit—Clackamas County Area,Oregon(OR610) 0) Map unit symbol Map unit name Rating Acres in A01 Percent of A01 25 Cove silty clay loam D 0.7 31.5% 76B Salem silt loam,0 to 7 percent slopes B 1.4 68.5'!, Totals for Area of Interest 2.1 100.0% 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97oo8 • emeriodesign.com Appendix B(2) Curve Number Table RUNOFF CURVE NUMBERS (TR55) Table 2-2a: Runoff curve numbers for urban areas RUNOFF CURVE NUMBERS (TR55) _ Table 2-2a: Runoff curve numbers for urban areas 1 Cover description CN for hydrologic soil group Average percent impervious Cover type and hydrologic condition area2 A B C D Fully developed urban areas (vegetation Use CN = 89 for Cove silty established) clay loam — Open space (lawns, parks, golf courses, cemeteries, etc.) 3: Poor condition (grass cover <50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover >75%) 39 1 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding Use CN = 79 for Salem silt - right-of-way) loam Paved; open ditches (including right-of-way) 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: _ Natural desert landscaping (pervious areas only) 4 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: _ Commercial and business 85 89 92 94 95 _ Industrial 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 6445 SWFallbrook Place,Suite too • Beaverton,OR 97008 • emeriodesign.com Matt Boggs Project Manager APPENDIX B(3) New Look Development E—Matt@NewLookDev.com P—(503)577-2646 8 July 2021 Re: Infiltration testing at empty lot next to 15868 SW Kimball Street, Lake Oswego OR Field Investigation: Rapid Soil Solutions (RSS) has attempted to performed one (1) infiltration tests. Figure 1 below shows the project site location. Soils found on site match those in by DOGMI. RSS found dry stiff fine-grained soils SW Baleine St 1— cn rn 15811 15825 15879 15868 Figure 1 Infiltration Testing: RSS performed the testing as per the City of Lake Oswego storm water manual. RSS shows on our infiltration sheet the pre-soak and testing. RSS found the rate to be 3in/hr. Groundwater Based upon the Portland area ground water map it is 40ft below the site. fix. ,l ? 7 .? USGS 5098 The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, I ‘rp PROic r G�N�F,Qs�O 19744 PE i2 •REGON 1/(}, 15, 94\ -� ��1 C. MPN4' EXPIRES: 3 /-!di Z Mia Mahedy, PE GE. Rapid SoiloI irtions IIIC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results - — 1 4 ', t•• - « - . , HA#1 'er f‘. v... J . IL 111. . . -"47 . •Aii: ...._4:3 4 .Ilt N `i Preliminary Information SW Kimball St,Lake Performed By: Location: Oswego, OR; east of (Supervised by Mia Olenka Duncan 15868 SW Kimball St Mahedy,PE,GE) Date&Time: 7/6/21 at 12:30 Gm Instrument Used: Hand au:er Weather: 80°,mostly sunny Depth: 8 ft HA#1 A 4 hour presoak was started at 8:30 am with 16"of water. All 16"had drained at the end of the presoak, and the test was be_un at 12:30 .m. Soil Profile Detail Depth(ft) Description 0-1' Topsoil 1-3' Barely damp medium brown clayey silt 3-3.5' Coarse gravel with fine grained clay/silts 3.5-8' Barely damp beige clay Time Measurement(inches) Level Refilled To(inches) Rate (inches/hour) 12:30 - 16 - 1 10.75 - 10.5 1:30 8.5 12.5 4.5 2 10.5 13 4 2:30 11 - 4 3 6.25 11.5 9.5 3:30 10 - 3 Site Infiltration Rate(inches/hour) 3 Rapid I SoilSolOtions INC 503-816-3689 I mia@rapidsoilsolutions.com Matt Boggs Project Manager New Look Development 7685 SW Cirrus Dr. 32F Beaverton, Oregon 97008 E—Matt@NewLookDev.com P—(503)577-2646 18 May 2022 Re: Infiltration testing for Kimball Street, Lake Oswego, OR Dear Mr. Boggs, Field Investigation: Rapid Soil Solutions (RSS) has performed a total of one (1) infiltration test. The figure below shows the site RSS found a mixture of fine-grained Missoula Flood Deposits, Off and fractured basalt. Testing was performed for future storm water design. Location shown below. o0 al, 15811 46 1 15825 $8 15879 - _ 15868 15921 Ael,, r Infiltration Testing and ground water Infiltration testing was performed as per the Lake Oswego Storm Water Manual 2018. The first hole was a test pit as the south side of the lot is fractured basalt and cobbles on 11 May 2022. The test was performed between proposed lots 4/5 and the rate was 720in/hr. See attached soils logs. Additional test holes were excavated between lots 1 and 2 and then on lot 3. Fine grained soils were found with the excavator. We returned on 13 May 2022 to hand excavate those holes using a hand augur for a better pre-soak and readings. RSS found the soils to be hard white elastic CLAY and when we excvated to a depth of 4ft and performed the four(4) hour pre-soak they did not drain at all. Ground water Based upon the USGS groundwater is within 40ft of the site. v.. urham1 I i-r USGS 2008-5059 Rapid I I So i L S o`w t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Test hole locations for lots 1-3 =• - Did not drain at all during FA ...,� e=-e� � ,, ` "m— ' .", . the pre-soak phase Q` _ e• - e e-- 4.#-=_ _ ' - .-eB�- a-- [ ; - —e 6 .- e. e. ®-- -- 0 0i= e, R �1 Q: HA#2, `.sue t1 e $. a =_ A; / ©j._bt - q - -, T.s • -; a _ . a. a-- a!-: 1 o �- _ ©-, e- , . -_r - ,,-.e. e- TI.. maw..*In --Conclusion RSS recommends onsite infiltration for lots 4 and 5. With lots 1-3 drainage being piped to storm water basin that is set aside on lot 4. The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, CEO PR0FF 4, Sol cr 19 44P O. 7•REGON ,- '1 GAY15 ` • 1 �41 C. MAN EXPIRES: /t- 2), /- Zdi 2_ Mia Mahedy, PE GE Rapid I I S o i L S o`V t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results .�, • {,-- .._ - .N N$7 .-. �� ,— i se- 5 S _ - �� .. -V -i .s.. vfva TL ua � _ Or- •- ,i-.. 0oit - - it so n - -, . a- °r ._ I-I .a. -- - - Preliminary Information Performed By: Location: Kimball Street (Supervised by Mia Rick Sands Mahedy, PE,GE) Date& Time: 5-11-22, 830 am Instrument Used: excavator Weather: cloudy Depth: 5 FT TP#1 0 lft Topsoil 1-4ft Damp, dark brown silty with cobbles 4-5ft Cobbles and fractured basalt Time Measurement(inches) Level Refilled To (inches) Rate(inches/hour) 8:30 12 8:31 0 12 8:32 0 12 8:33 0 — Site Infiltration Rate(inches/hour) 720in/hr Rapid Soil Sol lions INC 1 503-816-3689 mia@rapidsoilsolutions.com APPENDIX B(4) < 4B > < 4A > Share Drive Lit 4 6P 7P Drywell D rywe l l Subcat Reach 'on. Link Routing Diagram for 0980-001 Baleine HydroCAD ---\___ Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 4A: Lot 4 Runoff = 0.087 cfs @ 7.88 hrs, Volume= 1,256 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 5,080 98 roof impervious 5,080 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4A: Lot 4 Hydrograph r T ,- 0.095- I I •Runoff 0.09 10.087 cfs @ 7.88 hrs I 0.085- F F Type IA 24- hr l' 10-year Rainfall=3.20" 0.075 0.07 Runoff Area=5,080 sf 0.065= - 0.06= / Runoff Volume=l,256 cf 3 °a05 ! Runoff Depth=2.97" = - O 0.045_ % , Li1 1 �1 r Tc=5.0 r i n 0.04= 0.035= CN=0/98 0.03 0.025: 0.020.015 0.01 0.005 / 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 4B: Shared Drive Runoff = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 8,095 98 impervious, dwy 8,095 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4B: Shared Drive Hydrograph 0.15 I i I i i I I •Runoff I I0.139cfs@7.58hrsI I 0.14�' y _ i I T 24-hr-- 0.13 I I I 0.12_' __�_ j 1-0-year RairyfarC=3: 0"= 0.11'" Runoff Area=8,095 sf 0.1��) Runoff Volume=2,002 cf 0.09 Runoff Depths=2.97" �° 0.07 � Tc=�5.0 m i n 0.06_ CN=0/98 0.05 0.04='' I' %' 0.03 ' 0.02_' 1 0.010�/ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 4 Summary for Pond 6P: Drywell Inflow Area = 8,095 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf Outflow = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf, Atten= 0%, Lag= 0.9 min Discarded = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.99'@ 7.89 hrs Surf.Area= 22 sf Storage= 7 cf Plug-Flow detention time=0.9 min calculated for 2,002 cf(100% of inflow) Center-of-Mass det. time= 0.9 min ( 666.0 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.00' 17 cf 2.33'D x 4.00'H Drywell Inside#2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.00' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.00' 360.000 in/hr Exfiltration over Wetted area above 218.00' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.139 cfs @ 7.89 hrs HW=218.99' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.139 cfs @ 0.01 fps) Pond 6P: Drywell Hydrograph / ❑Inflow 0.15 0 Discarded 10.139 cfs%9hrs 1 Inflow Area=8,095 sf 0.1 LL 0.13 Peak Elev=218.99' 0.12 0.11= % Storage=7 cf '`- 0.08= ° 0.070.06 0.05 0.04= 0.03 0.02 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 sin 04804 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Pond 7P: Drywell Inflow Area = 5,080 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.087 cfs @ 7.88 hrs, Volume= 1,256 cf Outflow = 0.087 cfs @ 7.91 hrs, Volume= 1,256 cf, Atten= 0%, Lag= 2.1 min Discarded = 0.087 cfs @ 7.91 hrs, Volume= 1,256 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 219.74' @ 7.91 hrs Surf.Area= 22 sf Storage= 10 cf Plug-Flow detention time= 1.8 min calculated for 1,256 cf(100% of inflow) Center-of-Mass det. time= 1.8 min ( 666.8 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.50' 17 cf 2.33'D x 4.00'H Drywell Inside #2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.50' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.50' 180.000 in/hr Exfiltration over Wetted area above 218.50' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.087 cfs @ 7.91 hrs HW=219.74' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.087 cfs) Pond 7P: Drywell Hydrograph 1 ❑Inflow 0.095 f I 0.087 cfs @ 7.88 hrs I __ ❑Discarded 0.09 Io.o87cfs@7.91 hrs l Inflow Area=5,080 sf 0008= Reak EIev=219.74' 0.075_ G 1 T L 0.07 / 1 . . Storage=10 cf 0.065= ; I I 1 1 0.06- II Y Y 0.055 0.05= / 1 1 T T 0 0.045= I I i i LL 0.035- 0.03_0.025 0.02All11111111" 0.015 0.005 , 1 , 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 4,8 50 Time (hours) Appendix C: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com z NOTES: 2 3GG // --- Z O o 0LLI 1. THE EXISTENCE AND LOCATION OF ANY UNDERGROUND UTILITIES OR G / W 0o Ie STRUCTURES SHOWN ON THESE PLANS ARE OBTAINED BY A SEARCH / 2 Q M O OF AVAILABLE RECORDS. TO THE BEST OF OUR KNOWLEDGE, THERE a V ARE NO EXISTING UTILITIES EXCEPT THOSE SHOWN ON THESE PLANS. / G 2- O ~o cNi O O THE CONTRACTOR IS REQUIRED TO TAKE DUE PRECAUTIONARY - tle�, MEASURES TO PROTECT THE UTILITY LINES SHOWN ON THESE u_ _IW N 0DRAWINGS. THE CONTRACTOR FURTHER ASSUMES ALL LIABILITY AND 1/1 0 W W RESPONSIBILITY FOR THE UTILITY PIPES, CONDUITS OR STRUCTURES SHOWN OR NOT SHOWN ON THESE DRAWINGS. O O _ / o cNi a o co O 2. INFILTRATION SYSTEM SHALL BE LOCATED A MINIMUM OF 10'FROM G10' 0 5' 10' 20' BUILDINGS AND A MINIMUM OF 5'FROM PROPERTY LINES AS - \ - / Q (/) W MEASURED FROM THE EDGE OF DRAIN ROCKG 0.1 2 1 SCALE: 1" = 10' Q QJ J 3. BUILDING CRAWL SPACE DRAIN LINE TO BE DAYLIGHTED. � Z 4. REFERROOF TO DRAIN ARCHIITECTURAL SHOWN PLANS I FORPACTUAL ALOCATION.TE ON D�--'' \--' 1. �D ID `'77D --"—`D J 1—'4. X LL / G .4ill H SITE NOTES: 0 _ \ U ALL DIMENSIONS AND SQUARE FOOTAGE ARE / \ D APPROXIMATE FIGURES. . / D \ 491/ 441(CONTRACTOR TO ENSURE DRIVEWAY SLOPE TO DRAIN i2/)DD-/Dji D �20 _ � � V GNOV m AWAY FROM THE PROPOSED GARAGE AND SHEET FLOW • • • • • • • • • • • • • • • • .. .. • —• — TO TRENCH DRAIN AS SHOWN _• •�•_•_• •_•_•_•// •_•_• •_• F....... . ..... . . .....r. ._._.:. . ._._. . G G• G ALL UTILITIES WILL BE INSTALLED UNDERGROUND D%1/ �T(' Y \ \ IX CONTRACTOR IS TO PROVIDE A "HUB & TACK" SURVEY I G , i_sG PRIOR TO SCHEDULING A FOOTING INSPECTION �a a\ w.4. I— WDD, o u�UD,LL'\uDD _:_�l. _ r 7 1 . 1 I I i G G PL 10'MIN.SEIBACK TO I \N 21 , I ,/ \ 7601, O BUILDING FOUNDATION . IIII II llII a IA"CESS MAANCE LID a D 224.0' \ 1� G / \ II III IIII I�I11: I II IIIII'II IIII II f L, a ` /\ / \ = .; 1, I II I \. III I II I II=I II I I I �I I nn1nlnl I IV,IIII L \ /I T I I I re* 1I lI I N I = TnnnnnnnlTAI •1000f I12 a PEFnnnnLnnnnn° / HI I II I IY 0 0 0 rin' ECTIOI III II I r nInInnInnInI Y l. SNInInInTInInI ET 6"SLAB THICKNESS ''' , % / DD GaTAX LOT2002tao' I In . .. I. Unnnl1lnllf=lllll : _n n n n n I R n a\ I 3 UI I I I-I n n n lI II II28 NEER 6Y4" / N IIIIT I IIII-II IIII E1 NOWELL I=1 IIL? / NZ III I I IfIII -lI I I - � a. , 4 G si O I II=1 I I I I _ n onnnnnn, ln INVERT 1� (_ E. LU 3/4°-2 1/2'COMPACTED CLEAN \ 3 / CC ANGULAR ROCK GEOTEKTILE FABRIC TO BE PLACED BETWEEN DRYELL&SURROUNDING 6"SLAB THICKNESS / ° o a cDRAIN ROCK&NATIVE SOILS -1 > PROPOSE ° 0, ROOF 28"DRYWELL AT 6'DEEP FOR o W a a 28" DRYELL DETAIL-SHARED DRIVE a D ROOF&DRIVEWAY DRAIN ONLY. 48 N.T.S. TRENCH DRAIN DETAIL ad >D, 0 N. N.T.S. � N \) PROPOSED TRAP CATCH BASIN ** 12"MIN. SOLID SCREW /a c a d <D I (SEE DETAIL THIS SHEET) _ o c r ��DOWN LID _ _ a 2D o /i /� /� �� CONNECT TO ROOF 10' I Li'of§ rye 14^M * D 3"PIPE(MIN) 1 L_ D — DRAIN SYSTEM d A;u,8 0 PL m 10'MIN.SEIBACI(TO .r.o BUILDING FOUNDATION INLET 18 MIN. a[ ;Da o g O_M z ID s m m �1G (DOWNTURNED �a DI 0 10' LLww ACCESS N TENANCE LID OUTLET ELBOW 0 ~ I PIPE OR HOOD) n y m n Ir I n n u'n=n n n n B.N n n n n:II.n n n zzas *THE BOTTOM OF THE INLET PIPE MUST DI BE S O. I II II I II 11-11=11 IA II II. II II II II II II 11 0 TI II II II II n:IIn II II II n II II II I. LOWER THAN THE TOP OF THE OUTLET PIPE n n n nn n I I I • n- nnnnnnn 0 � o I B B B B 8=11 B B -.� i .I B N B B B 8=11 B B II- Q n n n n n n n n n nnnn m, nnnn > nnnnn.madam iRIBBBBBBBni nnnnn nn r Innnnnnnn- II IIIIIII IIIIIIII:II nI III II ..0 0 0■ 120 PERF II III lllllll IIIIII TITAN g TALIIIn IIn IIII=IIIIIIRIIn ,- o 0 0IA 4 SECOONSIIn II Ill�nll nllnll nllnI r —. — _ ..„...„...,..r.__,._Y 11 11 11 11=11 11 11 11 1 15833 INVERURIE RD AS 5' II II II II II II II II IIIII II II • • �I •I��I;,Il;;ll;;ll;;ll;;.lf.;ll;;ll;;ll;;�l;; SILT TRAP BASIN DETAIL - - - _ - ■ ' TAX LOT 300 II I I 1 I L T i II IY MEI I I I I " N.T.S.I �I I I I II I IALiIl = I I - I I I 1 O ss _ I I IIT I II I ,IIIII I= D - n nnna„=. - 15868 KIMBALL ST 3/4'-2 I/2'CGMPACIED CLEAN TAX LOT 2901 Cr0ANGULAR ROCK GEOTEXTILE FABRIC TO BE PLACED BETNEEN DRTRELL&SURROUNDING O „0 0 DRAIN ROCK&NATIVE SOILS I SHEET m W 28" DRYELL DETAIL- LOT 4 1 oF/ a N.T.S. / o EMERIO ENGINEERING•SURVEYING• DESIGN Drainage Report Lot 5 of 5 Lot Subdivision at Tax Map 2S1E 07CA Tax Lot 100, 2902, 3000 Lake Oswego, Oregon Emerio Project Number: 0980-001 City of Lake Oswego Permit Numbers: LU 23-0002 Date: 12/23/2022 Rev 1: 09/14/2023 `c3cV PROFFs�i 81153PE r—DocuSigned by: A E C I "qqq, OV 750E,22, 4�� yuq V Py EXPIRES: 12/31/2023 Prepared For: Prepared By: Kelly McCall Joshua Ayers, PE Renaissance Homes Emerio Design, LLC 16771 Boones Ferry Road 6445 SW Fallbrook PI, Suite 100 Lake Oswego, Oregon 97035 Beaverton, Oregon 97008 kmccall@renaissance-homes.com joshua@emeriodesign.com (503) 746-8812 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Table of Contents: APPENDIX A (1) Vicinity Map APPENDIX B (1) Soil Classification Map-"Soils Survey for Clackamas County" (2) Curve Number Table (3) Infiltration Tests (Rapid Soil Solutions, July 8, 2021 and May 18, 2022) (4) HydroCAD Plot APPENDIX C (1) Site Map (2) Drywell Detail 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Project Overview and Description The project site is located on the south side of SW Baleine Street between the southeast corner of the intersection of SW Kimball Street & Baleine Street and the southwest corner of the intersection of Inverurie Road. The existing condition is a large undeveloped lot. Five lots will be created with a new single-family home and attached garage on each lot. All new impervious area to be created by this project on this lot will be directed to new onsite stormwater systems. This report addresses stormwater management for Lot 5 and includes the analysis of the shared driveway. Refer to Appendix C(1) for site map. The property is zoned R-7.5 (Residential, 7,500 SF lots) with a lot size of 13,550 SF. The proposed project will address the following elements of the Lake Oswego Stormwater Management Manual: Site Assessment and Feasibility Analysis, Onsite Stormwater Management, and Design for Water Quality. Site Assessment and Feasibility Analysis The proposed site is composed of Salem silt loam, hydrologic soil group B. Preliminary investigation by Rapid Soil Solutions on July 8, 2021, measured infiltration rates of 3 in/hr at 8 feet below ground surface. At a test pit closer to the shared driveway and southern lots 4 and 5 of the development, infiltration testing was performed on May 11, 2022, and yielded a measured rate of 720 in/hr at 5 feet below ground surface. During field exploration groundwater was not encountered in test pits; however, Portland area groundwater mapping shows groundwater to be approximately 40 feet below ground surface. Onsite stormwater management is proposed for this site. Onsite Stormwater Management Both the shared driveway and the onsite Lot 5 impervious areas will achieve onsite stormwater management by the same methodology: a drywell system is proposed to infiltrate 100% of the driveway runoff during the 10-year 24-hour design storm. A lynch style catch basin with an 18-inch sump will provide pretreatment prior to the DEQ defined UIC (drywell). The shared driveway system will be installed in an easement on Lot 4. Reference drywell system dimensions and modeling data below. Input Data: Impervious Area: 8,095 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 224.00 Feet Drywell Bottom Elevation: 219.00 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 218.0 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.14 CFS Peak Flow Rate in Infiltration Device: 0.14 CFS Peak Water Surface Elevation: 218.99' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 5' below finish grade. Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. Lot 5 Areas Analysis Input Data: Impervious Area: 6,524 SF Curve Number: 98 Time of Concentration: 5 Minutes Drywell Quantity: 1 EA Drywell Depth: 5 Feet Drywell Diameter: 28 Inches Assumed Finish Grade: 225.50 Feet Drywell Bottom Elevation: 220.50 Feet Drain Rock Area (1' side cover): 5.33 Feet x 5.33 Feet Drain Rock Bottom Elevation: 219.50 Feet Drain Rock Void Ratio: 33% Measured Infiltration Rate: 720 Inches/Hour Design Infiltration Rate: 360 Inches/Hour Infiltration Rate Factor of Safety: 2 Design Storm Return Period: 10-Year Design Storm Depth: 3.2 Inches in 24-hours Storm Type: Type 1A Output Data: 10-Year Flow from Roof: 0.112 CFS Peak Flow Rate in Infiltration Device: 0.111 CFS Peak Water Surface Elevation: 221.10' Draw Down Time: < 1 Hour from end of storm As shown above, at the peak elevation for the designed infiltration rate, the water level will rise to 4.40' below finish grade. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Overflow Discharge: In the event of flows greater than the design capacity of the drywell system, flows will bubble up at the downspout connections or catch basin rims and flow overland to the east across adjacent lots and into the delineated wetland. UIC Review with Oregon DEQ This project will use a UIC system that receives runoff from the shared residential driveway areas; therefore, this system will require registration and approval with DEQ under Authorization by Rule requirements. Pretreatment of the driveway areas is satisfied by providing the minimum required 18 inches of sump below the snout in a silt trapped basin. Engineering Conclusions Based on the results of this analysis, the proposed stormwater system meets the 2020 City of Lake Oswego Stormwater Management Manual standards. 6445 SW Fallbrook Place,Suite ioo • Beaverton,OR 97008 • emeriodesign.com Appendix A: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix A(1) Vicinity Map - ' 1 t. -. ia.�[ifSllYStd]Spfin�.RJ..._.I \ L \ ..I I.r..._.._ ✓/ ✓ ,\Mfl4 _11.1�.....� ...�. F,,,,,,II.tI^.II I .�^_._.._ SrV I�r11.iIJ it _ ..U,CCC'', ` _ y 'll•. "' P.* .ni I Ai. f�J.., rl t - ra,kha: SIB �..i. ry � r. If n1 SITE W 1,6 r•1 K Lae .... I _ P.j1p13121 P1 :^�aknJa Village '. F;TA-61;1 Mt:Metter, I n Sh.1A..sV•.r.. �; Lyle Wove A11r,J n Rc VV, nl JS1c� �,,Elean Wry 5t .Cra t Schod (( _ 1 W rods 'I � O` _ _ w�tt`eit ..-. \�` -\.µ a (+r Mye ; i2d e Lakrt` ` 'r l �t.J,,h oSe +, I .1`e rc . l I i r. r I �,-� ` a. tr IV f lw oA L ? Flrwdf .�. r,d' - - 1 it I w M.-taro., I ,, t _3r ,r a. i rr,Raa 1�eero}�•i ,, �= 1 P - 1 F i - n 1 rp Af. t• .r•. ` F C b�i " 1I'- .,rh ct Pam' .I�—ll. : .l . Pr. i t 2 j I 4 rt Lamold Spnlr, 1 -..L 1 "''' err„ Naheal AP, Vilest P� r / tvi o,. �r,,li�r,.1 W.., r _ v v '�7 Chapman War Ga /�c L: .�•.\��]Ito � ri'r,.e✓, Y. rIFt bo �t r' Q \ ,y� wJ• - rcY i Cobb Way -N I I Pia /! .I QW ey yVddw�x,d SI z , \v> Wren: Si • Tile Chlldrens _ ZI - Haven Sr [�— r Nqu1 A,a(bnly in W1110 41 1 l+ee Fiyetl CI , U I f N c.t o J r t �-L7 :� � I �f-_ `! //.,�.LJeL� �s 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com Appendix B(1) Soil Classification Map F..% ;•.t:k ,V,711%,:, .' . . ' ''' :-.; -- r, . . 1 - • "Z. ...4• ':" 4 :- • ifirA "i 4,,, 'itic . ", As- • • •-- '....•••t• ', " - • •'•. . -s- it. 1,:..,- . .: . . v ,di*, . ,,, 34 Ate, - .. . ., • lik. ., • ., - • , •4 .4..; • , ._ -. .- :•,.. . ,:_1.4, ip• 404.,to itri,1 . . . ,s, t ., , . .,..,,, -14,z". . . . 1 1. A A.. . 10,41b. . ., .....is....:•:.4 ,. e yi ..,...'4, , .. .". :. . si,.1....I • • - •,, ... .'•'..s'..` MK, •. ir •.• ,,4 • tr " andIESIIIIMMIIII ...„: -_,N..._ •- pl.,- • -.elev.-- - ..A "A Itlitv .i.k. , • •• Alp • zt.' i , • .3,. :-,..467..ort ‘4,,, ,,i ..........., ._, :.7..„,,.. . „...,,:... , ,....„.• ,,.. ... .._ .. . . \,.,. . ...... .. ,,,,,....... ... ea ., ..,,4 , , . k• s 1- • ....... . . 41 . 0'. . l''• . --11f . ' • '4MA-4-4 • • • . P -',.4.> • 4.4r..c. ,..t.- .-., .• a'. • • "' ''4t.- :".1'r! r.:, ... 44C-iti Is illill SO.i.f', •1„. •I.•'''' liTe4s ,; ''' -. ' ' hil'i• 'i• ,.;..-.'•' ,'•' ' ir, :!.4/.. . i',. A\ j, :..:104 -. -• .•••• 'f ,,'1 . • • ., . . • .' ‘s' . •1,..•%. ) ...... — 1 xi .4.:. ''' ' '04.4,,,isk "e1, • ,.... , ' ir, 410 o ... ,,,.. ....... ., . If" . ti ' 400-.41- . , lifkr A g t ° ' • 1 4. ' • . ' 9.1 ' 1 ' • ' "41 1.0• t t\• ' i- I IP. A 1• "'V 1 ... ..• " IC• 4:. .... 1[1.",It.,, ' L.1211111e 4 ,' \ '' i • ' • . .. 1.===1. :00/1=r, i• ••IMICO2.. .,16••• ' table, Itydroloyi,Soil Group-Summary By map Iiint (,, Summary by Map Unit-Clackamas County Area,Oregon(OR610) Summary by Map Unit-Clackamas County Area,Oregon(OR610) 4 Map unit symbol Map unit name Rating Acres in A01 Percent of A01 25 Cove silty clay loam D 0.7 31.5% 76B Salem silt loam,0 to 7 percent slopes B 1.4 68.5% Totals for Area of Interest 2.1 100.00/0 6445 SW Fallbrook Place,Suite too • Beaverton,OR 974308 • emeriodesign.com Appendix B(2) Curve Number Table RUNOFF CURVE NUMBERS (TR55) Table 2-2a: Runoff curve numbers for urban areas RUNOFF CURVE NUMBERS (TR55) _ Table 2-2a: Runoff curve numbers for urban areas 1 Cover description CN for hydrologic soil group Average percent impervious Cover type and hydrologic condition area2 A B C D Fully developed urban areas (vegetation Use CN = 89 for Cove silty established) clay loam — Open space (lawns, parks, golf courses, cemeteries, etc.) 3: Poor condition (grass cover <50%) 68 79 86 89 Fair condition (grass cover 50% to 75%) 49 69 79 84 Good condition (grass cover >75%) 39 1 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding Use CN = 79 for Salem silt - right-of-way) loam Paved; open ditches (including right-of-way) 83 89 92 93 Gravel (including right-of-way) 76 85 89 91 Dirt (including right-of-way) 72 82 87 89 Western desert urban areas: _ Natural desert landscaping (pervious areas only) 4 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) 96 96 96 96 Urban districts: _ Commercial and business 85 89 92 94 95 _ Industrial 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses) 65 77 85 90 92 1/4 acre 38 61 75 83 87 1/3 acre 30 57 72 81 86 1/2 acre 25 54 70 80 85 1 acre 20 51 68 79 84 2 acres 12 46 65 77 82 6445 SWFallbrook Place,Suite too • Beaverton,OR 97008 • emeriodesign.com Matt Boggs Project Manager APPENDIX B(3) New Look Development E—Matt@NewLookDev.com P—(503)577-2646 8 July 2021 Re: Infiltration testing at empty lot next to 15868 SW Kimball Street, Lake Oswego OR Field Investigation: Rapid Soil Solutions (RSS) has attempted to performed one (1) infiltration tests. Figure 1 below shows the project site location. Soils found on site match those in by DOGMI. RSS found dry stiff fine-grained soils SW Baleine St 1— Cn Cr) 15811 15825 15879 15868 Figure 1 Infiltration Testing: RSS performed the testing as per the City of Lake Oswego storm water manual. RSS shows on our infiltration sheet the pre-soak and testing. RSS found the rate to be 3in/hr. Groundwater Based upon the Portland area ground water map it is 40ft below the site. k AUSGS 5098 The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, ,��Eo PR OF�c. <crC� (aGINCF,QsiO CC 19244PE •REGON • 1/0V991 -�4/ 15, 1 C. M P EXPIRES: /7 /-14)2Z Mia Mahedy, PE GE. Rapid I Soil S o l ho l i o n s I I I C 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results - — 1 4 ', t•• - « - . , HA#1 'er f‘. v... J . IL 111. . . -"47 . •Aii: ...._4:3 4 .Ilt N `i Preliminary Information SW Kimball St,Lake Performed By: Location: Oswego, OR; east of (Supervised by Mia Olenka Duncan 15868 SW Kimball St Mahedy,PE,GE) Date&Time: 7/6/21 at 12:30 Gm Instrument Used: Hand au:er Weather: 80°,mostly sunny Depth: 8 ft HA#1 A 4 hour presoak was started at 8:30 am with 16"of water. All 16"had drained at the end of the presoak, and the test was be_un at 12:30 .m. Soil Profile Detail Depth(ft) Description 0-1' Topsoil 1-3' Barely damp medium brown clayey silt 3-3.5' Coarse gravel with fine grained clay/silts 3.5-8' Barely damp beige clay Time Measurement(inches) Level Refilled To(inches) Rate (inches/hour) 12:30 - 16 - 1 10.75 - 10.5 1:30 8.5 12.5 4.5 2 10.5 13 4 2:30 11 - 4 3 6.25 11.5 9.5 3:30 10 - 3 Site Infiltration Rate(inches/hour) 3 Rapid I SoilSolOtions INC 503-816-3689 I mia@rapidsoilsolutions.com Matt Boggs Project Manager New Look Development 7685 SW Cirrus Dr. 32F Beaverton, Oregon 97008 E—Matt@NewLookDev.com P—(503)577-2646 18 May 2022 Re: Infiltration testing for Kimball Street, Lake Oswego, OR Dear Mr. Boggs, Field Investigation: Rapid Soil Solutions (RSS) has performed a total of one (1) infiltration test. The figure below shows the site RSS found a mixture of fine-grained Missoula Flood Deposits, Off and fractured basalt. Testing was performed for future storm water design. Location shown below. o0 al, 15811 46 1 15825 $8 15879 - _ 15868 15921 Ael,, r Infiltration Testing and ground water Infiltration testing was performed as per the Lake Oswego Storm Water Manual 2018. The first hole was a test pit as the south side of the lot is fractured basalt and cobbles on 11 May 2022. The test was performed between proposed lots 4/5 and the rate was 720in/hr. See attached soils logs. Additional test holes were excavated between lots 1 and 2 and then on lot 3. Fine grained soils were found with the excavator. We returned on 13 May 2022 to hand excavate those holes using a hand augur for a better pre-soak and readings. RSS found the soils to be hard white elastic CLAY and when we excvated to a depth of 4ft and performed the four(4) hour pre-soak they did not drain at all. Ground water Based upon the USGS groundwater is within 40ft of the site. v.. urham1 I i-r USGS 2008-5059 Rapid I I So i L S o`w t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Test hole locations for lots 1-3 =• - Did not drain at all during FA ...,� e=-e� � ,, ` "m— ' .", . the pre-soak phase Q` _ e• - e e-- 4.#-=_ _ ' - .-eB�- a-- [ ; - —e 6 .- e. e. ®-- -- 0 0i= e, R �1 Q: HA#2, `.sue t1 e $. a =_ A; / ©j._bt - q - -, T.s • -; a _ . a. a-- a!-: 1 o �- _ ©-, e- , . -_r - ,,-.e. e- TI.. maw..*In --Conclusion RSS recommends onsite infiltration for lots 4 and 5. With lots 1-3 drainage being piped to storm water basin that is set aside on lot 4. The analysis, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of explorations. Any questions regarding this report please contact me at the below number or email. Sincerely, CEO PR0FF 4, Sol cr 19 44P O. 7•REGON ,- '1 GAY15 ` • 1 �41 C. MAN EXPIRES: /t- 2), /- Zdi 2_ Mia Mahedy, PE GE Rapid I I S o i L S o`V t 101 1 S LLC 503-816-3689 mia@rapidsoilsolutions.com Rapid Soil Solutions Infiltration Test Results .�, • {,-- .._ - .N N$7 .-. �� ,— i se- 5 S _ - �� .. -V -i .s.. vfva TL ua � _ Or- •- ,i-.. 0oit - - it so n - -, . a- °r ._ I-I .a. -- - - Preliminary Information Performed By: Location: Kimball Street (Supervised by Mia Rick Sands Mahedy, PE,GE) Date& Time: 5-11-22, 830 am Instrument Used: excavator Weather: cloudy Depth: 5 FT TP#1 0 lft Topsoil 1-4ft Damp, dark brown silty with cobbles 4-5ft Cobbles and fractured basalt Time Measurement(inches) Level Refilled To (inches) Rate(inches/hour) 8:30 12 8:31 0 12 8:32 0 12 8:33 0 — Site Infiltration Rate(inches/hour) 720in/hr Rapid Soil Sol lions INC 1 503-816-3689 mia@rapidsoilsolutions.com APPENDIX B(4) <4B > Share Drive Lit 5 U U 6P /8ND Drywell Drywell Subcat Reach 'on• Link Routing Diagram for 0980-001 Baleine HydroCAD Prepared by Emerio Design, LLC, Printed 12/23/2022 HydroCAD®10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 4B: Shared Drive Runoff = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 8,095 98 impervious, dwy 8,095 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4B: Shared Drive Hydrograph 0.15 I i I i i I I •Runoff I I0.139cfs@7.58hrsI I 0.14�' y _ i I T 24-hr-- 0.13 I I I 0.12_' __�_ j 1-0-year RairyfarC=3: 0"= 0.11'" Runoff Area=8,095 sf 0.1��) Runoff Volume=2,002 cf 0.09 Runoff Depths=2.97" �° 0.07 � Tc=�5.0 m i n 0.06_ CN=0/98 0.05 0.04='' I' %' 0.03 ' 0.02_' 1 0.010�/ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 5: Lot 5 Runoff = 0.112 cfs @ 7.88 hrs, Volume= 1,613 cf, Depth= 2.97" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Type IA 24-hr 10-year Rainfall=3.20" Area (sf) CN Description * 6,524 98 roof impervious 6,524 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 5: Lot 5 Hydrograph r Y r Y 1- -1 r I I r r I t 0.125 I I I I I I I I I I = i I I I I I I I I I I I I I ■Runoff �0.12 ,--I- +--r rt y -+ I I I 10.112 cfs @ 7.88 hrs I I I I I I I I I I 0.115-',- II II I I I 1 1 i A I iI 1 1 I 1 - 0.105=' T I I I I I 1 1 I I 1 I 1 0.1 '---I t 1-0-year Rai rifati i3.2fl�'-- 0.095-' T j� I I 1 1 I 1 I 1 I I 1 I I I 0.09_ , %J�f �I 1 L I L J f�ctnz ff A1�ea=6 524 sf 0.00.075_ T r r T r 1 r r r 1 r T 0.08J 01■ rr p riO l-'MQtumY' —1I,6'L -cf - I-- I I I I I I I I w j Runoff Depth-2.97" -- / 1 1 I 1 I 1 .9-.0.065= J1I - 0.06 -, I I I I I Li 0.055- ) - I I 1 1 I 1 I 1 I 1 I T Ie 'r./�ill i I I 4-I 1 I I III I I 1 0.045;/)1I ' 1 L 1 L 1 1 1 L J 1 0Na98 � r r T YI/ 0.04 0.035; 1 1 1 1 1 00 02� ^ �� , 0.0154" �,-- 0.01;, I 0.005=" 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 s/n 04804 ©2018 HydroCAD Software Solutions LLC Page 4 Summary for Pond 6P: Drywell Inflow Area = 8,095 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.139 cfs @ 7.88 hrs, Volume= 2,002 cf Outflow = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf, Atten= 0%, Lag= 0.9 min Discarded = 0.139 cfs @ 7.89 hrs, Volume= 2,002 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 218.99'@ 7.89 hrs Surf.Area= 22 sf Storage= 7 cf Plug-Flow detention time=0.9 min calculated for 2,002 cf(100% of inflow) Center-of-Mass det. time= 0.9 min ( 666.0 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 219.00' 17 cf 2.33'D x 4.00'H Drywell Inside#2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 218.00' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 218.00' 360.000 in/hr Exfiltration over Wetted area above 218.00' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.139 cfs @ 7.89 hrs HW=218.99' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.139 cfs @ 0.01 fps) Pond 6P: Drywell Hydrograph / ❑Inflow 0.15 0 Discarded 10.139 cfs%9hrs 1 Inflow Area=8,095 sf 0.1 LL 0.13 Peak Elev=218.99' 0.12 0.11= % Storage=7 cf '`- 0.08= ° 0.070.06 0.05 0.04= 0.03 0.02 0.01 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) 0980-001 Baleine HydroCAD Type IA 24-hr 10-year Rainfall=3.20" Prepared by Emerio Design, LLC Printed 12/23/2022 HydroCAD® 10.00-24 sin 04804 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Pond 8P: Drywell Inflow Area = 6,524 sf,100.00% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 0.112 cfs @ 7.88 hrs, Volume= 1,613 cf Outflow = 0.111 cfs @ 7.91 hrs, Volume= 1,613 cf, Atten= 0%, Lag= 2.2 min Discarded = 0.111 cfs @ 7.91 hrs, Volume= 1,613 cf Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.005 hrs Peak Elev= 221.10' @ 7.91 hrs Surf.Area= 22 sf Storage= 13 cf Plug-Flow detention time= 1.8 min calculated for 1,613 cf(100% of inflow) Center-of-Mass det. time= 1.8 min ( 666.8 - 665.1 ) Volume Invert Avail.Storage Storage Description #1 220.50' 17 cf 2.33'D x 4.00'H Drywell Inside #2 35 cf Overall - 6.0" Wall Thickness = 17 cf #2 219.50' 25 cf 5.33'D x 5.00'H Rock Section 112 cf Overall - 35 cf Embedded = 77 cf x 33.0% Voids 42 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 219.50' 180.000 in/hr Exfiltration over Wetted area above 219.50' Excluded Wetted area = 22 sf Discarded OutFlow Max=0.111 cfs @ 7.91 hrs HW=221.10' (Free Discharge) 4-1=Exfiltration (Exfiltration Controls 0.111 cfs) Pond 8P: Drywell Hydrograph /0.125 ❑Inflow 0.12�� o.��z@�.aahrs ❑Discarded 0.115 ' I 0.111cfs07.91hrs - - = 2�r�flow Area 6,5 4 sf-- Peak EIev=221 .1-0' 0.095 I 0.09= ' , . I- Stora-ge=13 cf-- 0.085� / I 0.08 ' ' P 1_ �0.075 -�. °0.065 ' z /. � 3 0.06� LT°°0.055 O O 0.05� 0.045 ' /� 0.04 ::EuI , 0.010_ 0.005ii 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (hours) Appendix C: 6445 SW Fallbrook Place,Suite too • Beaverton,OR 97o08 • emeriodesign.com NOTES: �© � \) \ 0 1. THE EXISTENCE AND LOCATION OF ANY UNDERGROUND UTILITIES OR \ /A - - / N LLI 0 f STRUCTURES SHOWN ON THESE PLANS ARE OBTAINED BY A SEARCH \ �7 \ Q M 0 OF AVAILABLE RECORDS. TO THE BEST OF OUR KNOWLEDGE, THERE �� a - y \ a L N ARE NO EXISTING UTILITIES EXCEPT THOSE SHOWN ON THESE PLANS `N. . ° a ti THE CONTRACTOR IS REQUIRED TO TAKE DUE PRECAUTIONARY \ _d 2 / \ 0 O 0 MEASURES TO PROTECT THE UTILITY LINES SHOWN ON THESE )a < /� TAX LOT 200 J O Ue DRAWINGS. 7HE CONTRACTOR FURTHER ASSUMES ALL LIABILITY AND / - �\ --- 1 1 G ; W CNI LLI RESPONSIBILITY FOR THE UTILITY PIPES, CONDUITS OR STRUCTURES O A - - - SHOWN OR NOT SHOWN ON THESE DRAWINGS. N\ , a d 4 \ — — — 0 N 2. INFILTRATION SYSTEM SHALL BE LOCATED A MINIMUM OF 10'FROM /a 9 ° "/�> G a 0 0 BUILDINGS AND A MINIMUM OF 5'FROM PROPERTY LINES AS /�� a a� U) U) Y MEASURED FROM THE EDGE OF DRAIN ROCK 3. BUILDING CRAWL SPACE DRAIN LINE TO BE DAYLIGHTED. ]\�C - �D� Z X O J 4. ROOF DRAIN CONNECTION SHOWN IN APPROXIMATE LOCATION. /)a _ ° ° >� O W I— )( LL REFER TO ARCHITECTURAL PLANS FOR ACTUAL LOCATION. 4 0 Q < 0 m I— >- SITE NOTES: 1 . a >a V 2 ALL DIMENSIONS AND SQUARE FOOTAGE ARE a �a /\ APPROXIMATE FIGURES. CONTRACTOR THE PROPOSED DRIVEWAY GARAGE ANDSHEETFLOW LOPE TO DRAIN ]�C a — AWAYm TO TRENCH DRAIN AS SHOWN a ALL UTILITIES WILL BE INSTALLED UNDERGROUND �oA O ■ ® X LU 2 CONTRACR IS TO PROVIDE A "HUB & TACK"PRIOR TO TO A FOOTING INSPECTION SURVEY a ' O 0in CL O PROPOSED 28"DRYWELL AT 6'DEEP FOR 1 O ROOF&DRIVEWAY DRAIN ONLY. 10' J 12"MIN. SOLID SCREW —I 15833 INVERURIE RD G DOWN LID TAX LOT 300 Ct 6" SLAB THICKNESS y 2" 1 10' �— \�, W%/\W y W 0 0 1 CONNECT TO ROOF lit O � 12"MIN. * %3"PIPE(MIN) DRAIN SYSTEM 6Y" 15868 KIMBALL ST � TAX LOT 2901 �0 � INLET 18"MIN. 1:' i', INVERT O �� PROPOSED TRAP CATCH BASIN " _:•. OUTLET(DOWNTURNED (SEE DETAIL THIS SHEET) .3 6" SLAB THICKNESS PIPE ELBOW OR HOOD) f *THE BOTTOM OF THE INLET PIPE MUST LIU BE O LOWER THAN THE TOP OF THE OUTLET PIPE TRENCH DRAIN DETAIL s 0 F SILT TRAP BASIN DETAIL 0 n U N.T.S. o N.T.S. 1 CC G .,: , a, Q ., G 1 o z N N h wIH G _ i PL 15891 INVERURIE RD ~o to'MIN.8EIBACK To G 1U TAX LOT 400 Law SI 8 0 BUILDING FOUNDATION I 4 Hi L � -10' m1.7 _1 oz Mmxx z j ACCE IENANCE UD 225.5' u>~LLy InIi, n a nT nnnn n nl#u Illr ym I = I I — • I I 1 0 n o10 f 1 n Inn nn1nnInn1. S oo IIwnInnnnnIII n=12InnI In I 1,1120RF „1 „1 ' 1F1 4 p n nnn o erIC[O11 nI nE KT TAX LOT 2801 FF 219'5 #11411111111T:1111 .I P,I e1111II11:1111IIII IIIIII11.11.111 gTAT ITR o , II II II W-11 I ➢ 14z II 1I II nnTEUiiEffIWEffIWII5„Ui" �I I�I111�1II II II11:II II1111111I III III.�I II III III ICI Il li ll:ll28 DIPAIETERil�111 III II.TI:II '113%ff��IIT�II��II11II1�II III IF-)Is',L If 1II111I II11 Cigii IILIIkIIL1=' `�II II=11 II II �' II.11 II II.11=”1- II'=11 II II II II'� II II II II III II II II II " I II II II II=11 II 1, II II n:-„ II II 4 II„I II ,I 1, II II II:1 1, II 3/4•-2 1/2'CCMPACIED CLEAN ANGULAR ROCK GEOIEXIILE FABRIC TO BE PLACED BETNEEN DRYWELL&SURROUNDING DRAIN ROCK&NATIVE SOILS 1.1 28" DRYWELL DETAIL SHEET / m A N.T.S. 10' 0 5' 10' 20' o 1 OF 0 / o SCALE: 1" = 10' o