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HomeMy WebLinkAboutSWP272158(1) ' TECHNICAL INFORMATION REPORT ' for SUMMIT PARK CITY OF RENTON, WASHINGTON ' PREPARED: JUNE, 1994 ' Triad Job No. 93-064 ' Prepared by: Reviewed by: ' MICHAEL MATHIA CLAY A. LOOMIS, P.E. =TAD CIATES TECHNICAL INFORMATION REPORT 1 for SUMMIT PARK CITY OF RENTON, WASHINGTON ' PREPARED. JUNE, 1994 Triad Job No. 93-064 ' Prepared by: Reviewed by: ' MICHAEL MATHIA CLAY A. LOOMIS, P.E. A. 0 2 9 S IDNALyG 1 rG sy T - Z Z- CIATES ' TECHNICAL INFORMATION REPORT FOR SUMMIT PARK TABLE OF CONTENTS: I. Project overview ' II. PreliminaryConditions Summary ry tIII. Off-site Analysis ' IV. Retention/Detention Analysis and Design V. Conveyance Systems Analysis and Designs ' VI. Special Reports and Studies VII. Basin and Community Planning Areas VIII. Other Permits ' IX. ErosiorJSedimentation Control Design ' X. Bond Quantities Worksheet, Retention/Detention Facility Summary Sheet and Sketch, and Declaration of Covenant ' XI. Maintenance and Operations Manual ' Appendix: 2 TECHNICAL INFORMATION REPORT FOR SUMMIT PARK ' TIR SECTION I. PROJECT OVERVIEW; The proposed project is to subdivide approximately 12.25 acres into 48 single units ' consisting of 8-triplex and 3-eightplex buildings on approximately 3.7 acres, a park, open space, and future development area. The rectangular shaped parcel lies on the east side of Talbot Road, near the City of Renton/King County Line (see Vicinity Map). More generally, ' the site lies within Section 31, Township 23 North, Range 5 East, in King County, Washington. Vegetation on the east half of the site consists of scattered second- and third-growth Coniferous and broad-leafed trees native to the Pacific Northwest. The understory consists of northwest native species including salal, sword fern, berry vines and grasses. The western half of the site is covered with tall pasture grasses and clumps of berry vines. The site generally slopes from east to west at approximately 10-13 percent. The S.C.S. Soils Map indicates the ' site is underlain by Alderwood soils Type C. The generally slopes in a westerly direction at a grade of approximately 12%. The runoff from the site flows to Talbot Road and is collected in a earth channel then flows to an existing 8" culvert to the west side of the road where it enters a forested area and flows in a sheeting manner to the west. The area immediately to the east and upstream contains ' approximately 7 acres and flows to the project site. The basin to the north contains approximately 11 acres and flows west to Talbot Road and enters a earth channel which bypasses the s1te and flows southerly along to the previously mentioned 8" culvert. The proposed construction on the site is proposed for the westerly 3.7 acres leaving the remaining 8.5 acres as natural open space. The site will consist of eight triplex units and three eight-plex units. Access will be via a new road ending in a cul-de-sac that will reach the triplex ' units and two driveways allowing access to the eight-plex units. Parking areas and driveways will allow for access to the eight-plex units. Road and driveway grades will reach a maximum of 14%because the existing ground is generally as steep. The site will be graded to fit the ' development within the proposed area into the existing terrain as best as possible. This will include excavation mostly in the higher reaches and embankment mostly in the lower areas in an effort to attain balanced volumes. The lower portion of the site w►11 have minor fills mostly ' in the parking lot areas and excavation for the bio-filtration swale and the detention pond. The upper portion will have some excavations reaching a depth of 6 to 8 feet. Because of the natural steepness of the site, rookeries will be constructed in an effort to allow for building placements and keep graded slopes to a minimum. A storm drainage will be constructed to convey flows as required to alleviate flooding and will detain developed flows at or below pre-developed rates. Sewer and water utilities will be installed per city standards within the project to serve the proposed units. An off-site water line extension is required from the end of an existing line at approximately 900 feet north of the site on Talbot Road to the site's south property line for a total of approximately 1200 feet of ' required construction. Frontage improvements will be required along Talbot Road consisting of match-up paving to the city's proposed improvements, curb gutter and sidewalk, and storm drainage. 3 King County Building and Land Development Division Page 1 of 2 TECHNICAL INFORMATION REPORT (TIR) WORKSHEET —:PART-.1 PROJECT 1WNER-AND PART 2 PROJECT LOCATION PROJECT EAGINEER. ANDDESCRIPTION ' Project Owner 1 N V I ISM M03TAG bey,Cfl2Q__ Project Name G- UM M tT— Address �i0; ��X 17y (3C21Uu��`�2fD0� Location Phone Township 3 M ' Project Engineer C �-(,DAM( �j Range Company ' X% Section J� Address Phone l l.UCL Tl+ Project Size 72 -� S AC t ( D 6f Upstream Drainage Basin Size f AC • ' T 4 OTHER PERMITS •Subdivision DOF/G HPA Shoreline Management ff � �Short Subdivision F-1 COE 404 0 Rockery ' E�:] Grading DOE Dam Safety ED Structural Vaults 0 Commercial FEMA Floodplain = Other Other COE Wetlands = HPA COMMUNITYPARTS SITE DRAINAGE Community ' Drainage Basin PART 6 SITE CHARACTERISTICS River 0 Floodplain ' 0 Stream M Wetlands (� Critical Stream Reach Seeps/Springs Depressions/Swales High Groundwater Table E�:] Lake Groundwater Recharge 0 Steep Slopes Other Lakeside/Erosion Hazard ' Soil Type Sllam}oe Erosion Potential Erosive Velocities �o u�wDt> [� Additional Sheets Attatched 1/90 ' Page 2of2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PAWS DEVELOPMENT LIMITATIONS tREFERENCE LIMITATION/SITE CONSTRAINT Ch.4-Downstream Ana sis O 0 0 Additional Sheets Attatched MINIMUM ESC REC UIREMENTS MINIMUM ESC REQUIREMENTS ' DURING CONSTRUCTION FOLLOWING CONSTRUCTION Sedimentation Facilities = Stabilize Exposed Surface Stabilized Construction Entrance = Remove and Restore Temporary ESC Facilities ' Perimeter Runoff Control 0 Clean and Remove All Silt and Debris Clearing and Grading Restrictions Ensure Operation of Permanent Facilities Cover Practices Flag Limits of NGPES Construction Sequence 0 Other 0 Other Grass Lined Channel 0 Tank 0 Infiltration Method of Analysis ' Pipe System 0 Vault 0 Depression -�,E--)u j-T- Open Channel 0 Energy Dissapator 0 Flow Dispersal Compensation/Mitigation Dry Pond 0 Wetland 0 Waiver of Eliminated Site Storage ' 0 Wet Pond 0 Stream 0 Regional Detention Brief Description of System Operation -�?rZ-ED irlGu 1T Vic, rtD -�sllc�7�0 P(�-Q R�x�5 U2 7 0 %b U _ j r�2-k--,� Facility Related Site Limitations 0 Additional Sheets Attatched Reference Facility Limitation (May require special strCtitural revievy) � Drainage Easement E=1 Cast in Place Vault 0 Other 0 Access Easement EJ Retaining Wall (23 Native Growth Protection Easement 0 Rockery>4'High 0 Tract E=1 Structural on Steep Slope 0 Other ' PART 14 SIGNATURE 6CT • • • 1 or a civil engineer under my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attatchments. To the best of my knowledge the Information provided li lG-9 here is accurate. ' 1/90 v r to N N to Ir1 N t/, TH AV S 7 N AV 10 84TH 4AV $ S M. AV 5• ,, STH AV S i .... 87TH.....AV -------- S-'� ;-t • 6Ar`$ ILA— �-- -- AV-- Y I W` 92N0 AV N N C Cy 94THAV S n PL S RR '12ry 96TH AY � o• � I � r11 Nl' 96TH AV S �' 96TH O w I Y• ;•1i- a 8"' ' ttttttt fl� w s ,�l` -' AY - TALB :•em us, r e. Z J, 96TH PL (/) N NSA !- 96TH N cr 3 4 f 98TH AV S '� / t-�VI vs 98TH PL S T G5 vAV SE �. e • 101 AV SE m >R w� n 101ST AV m ~'o lotsT CTSF 10 D AV o rF 1 g c 103R0 VS� torxo H 102N0 p� SE � ' ill; 102ND Ay SE ;! (n m 103R0 AV SE 103RD LSE 1 D 1D4TH �;I r 103 1:;A ,�r x SE �" AV SE 104TH PL SE 1174TH7{1r' , S of t n is>R 1 j l r, . 00 i m I O4TH PL S m N 4 .. �N•, .lom 106TH AV SE 106TH AV a"r�^ I SE g0� �Qg 106TH 306TH L SE <n = 3S Ni IDS ! N a PL SE r fn m 107TN AY E e 108 H AV o N ; 9200 N >R E m M xii t UOT IVp IIOTH AV~SE rn g g 108�jt, l,�m N ED x PLS� AV � t2 >C.110TH v N $ SE,I`0TH m vN .•'' V ..� 111TH AV SE. g m r. cl M $ \ E _�xt;zlt. I 112TH AV SE L m '0 16 Z \ �1117 �. 11JTH 4� K"•�`W+is'r =o..... m 114 !AVSE 114 AV SEA 'ui i 3S AY lrt\ :T�•W{Ti.' -! 2s'uslH. . 07 I IAI 1C, x+ �•�•� 116 H � � ti N y �n t AV SE m „y N 35 µ1LTi _ 99 r� n 1R N AV s E m m S I" 1v 118TH t 118TH AV SE TIR SECTION II. PRELIMINARY CONDITIONS SUMMARY ' The intent of this section is to make sure all preliminary approval conditions pertaining to site engineering issues have been addressed in the Site Improvement Plan submittal. The following is a list of the brief statements regarding how each Recommendation in the Hearing Examiner's letter dated May 24, 1994 has been addressed. ' 1. The ERC conditions listed in the Hearing Examiner report dated April 12, 1994, are addressed as follows: ' 1. A Wetland Mitigation Plan has been prepared to show the creation of a 0.81 acre wetland, buffer areas, along with plant types, etc., and will be installed prior to the recording of the final plat. ' 2. The applicant will submit a surety as required. 3. The access to the Wetland is incorporated into the plans and will be recorded with the final plat. 4. A fence will be located along the back of lots 10 through 18 and along the east side of lot 19 prior to the recording of the final plat. 5. A Native Growth Protection Easement will be shown on the recorded final plat. 6. A construction mitigation plan is included with the plans. 7,8. These are repeated conditions. The conditions stated therein have been addressed and included in the plan submittal. 9. The recreation facilities fee will be paid at the time of development of the residential units. t 10. Please see Recommendation 7 below. 11. The 20 foot wide access points have been incorporated into the plans and a note will be placed on the final plat. ' 2. This information will be shown on the final plat. 3. This information will be shown on the final plat. 4. This information will be shown on the final plat. ' 5. This information will be shown on the final plat. ' 6. This homeowner's agreement will be done prior to final approval. 7. This condition is subject to review and approval of the Fire Department, and will be ' addressed during plan review. 8. All Tracts will be clearly shown on the plat. ' 9. The builder will install the improvements as required. 10. These fees will be paid as required. ' / i 'rid,•' ''� , r - .ti;;!.�.y.'.'�,;� �,a� . . - ,�/ - losses I��i� �• Si/HMO l ,' ; • • ,�1111 • •, `r •. `y•rA4 YAP.1.71 ` - 11 Ln Moo so • • �� _ Via11 Q r • ti •tom/•• • • d• • • . 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I }•. n iP .c,' r��< P 9 r y�i..:l ��t y >• .a7 9}`3+f.'S# r<7 fYf' iaS4 Cif s �►y�j 4 tr r �i t �6�� � g�-,��s� c i� ((tFFi r•'Yy,n �A�r i—�— i. a:y r s.-,�r �, '.XG*,� .n `.. y •t�`�� J yG lr �� ,,... < «'►. r .1,,,,. ,t • .:1 t l y' /� ( js�'f J L�[}S•_ � `�'!- i TIR SECTION III. OFF-SITE ANALYSIS UPSTREAM DRAINAGE ANALYSIS FOR THE BASIN The area upstream of the site is approximately 18 acres in size. The area is partially ' developed with approximately one dwelling unit per acre. (Please refer to the Upstream/Downstream Map in the appendix). Seven acres of this upstream area flow to the site along the easterly boundary and 11 acres flow to the site in an existing ditch along Talbot Road at the north property line. The 7 acre portion is partially developed with single family units. DOWNSTREAM DRAINAGE ANALYSIS Please refer to the Upstream/Downstream Drainage Map and accompanying spreadsheet in the appendix for identification of specific reaches in the downstream drainage system. As indicated in the spreadsheet, there were no visual problems with flooding, capacity, or overtopping. CORE REQUIREMENTS: 1. DISCHARGE AT THE NATURAL LOCATION: ' Discharge from the site will occur at the natural location along Talbot Road through an existing 8" culvert approximately 60 feet north of the south property line of Summit park. The existing 8" culvert will be replaced per the City's plan with an 18" culvert. 2. OFF-SITE ANALYSIS: RESOURCES USED FOR ANALYSIS Adopted Basin Plan The site is located in the Green River Basin. Basin Reconnaissance Summary Report The site lies within the Black River Drainage Basin as defined in the King County ' Basin Reconnaissance Program Summary Volume 1. Runoff from the site flows through a heavily vegetated area and enters Springbrook Creek approximately 1/2 mile downstream. The Reconnaissance Summary indicates that Springbrook Creek has no reported problems ' downstream from the site. Critical Drainage Area Maps The site is not located in any of the critical drainage areas discussed in the reference ' section of the 1990 King County Surface Water Manual. Floodplain/Floodwqy Maps The FEMA Flood Insurance Rate Map indicates the site lies outside any 100-year flood plain. Sensitive Areas Folio ' The King County Sensitive Areas Maps did not reveal the site to be in a problem area in regard to wetlands, erosion hazard, landslide hazard, flood plain or seismic hazards (please refer to the appendix for the appropriate maps). ' SWM Division Drainage Investigation Section Problem Map The SWM Division Drainage Investigation Section Problem Map was researched and there have been no complaints in this particular area. ' Wetland Inventory Notebook The Wetland Inventory Notebook indicated there were no wetlands located on the site or in the surrounding area, but two wetlands have been flagged on the site by Terra Associates, ' Inc. 5 SPECIAL REQUIREMENTS: 1. CRITICAL DRAINAGE AREAS: The site does not lie within a Critical Drainage Area. 2. COMPLIANCE WITH AN EXISTING MASTER DRAINAGE PLAN: The site does not lie within an Existing Master Drainage Plan. 3. CONDITIONS REQUIRING A MASTER DRAINAGE PLAN: The project does not meet the conditions requiring a Master Drainage Plan. ' 4. ADOPTED BASIN OR COMMUNITY PLANS: The site does not lie within an Adopted Basin or Community Plan. 5. SPECIAL WATER QUALITY CONTROLS: The project does not meet the requirements for Special Water Quality Controls. ' 6. COALESCING PLATE OIL/WATER SEPARATORS: The project does not meet the requirements for Coalescing Plate Oil/Water Separators. 7. CLOSED DEPRESSIONS: There are no closed depressions on the site. 8. USE OF LAKES, WETLANDS OR CLOSED DEPRESSIONS FOR PEAK RATE RUN-OFF CONTROL: This requirement does not apply. 9. DELINEATION OF 100-YEAR FLOODPLAIN: No 100-year floodplain exists on the site. ' 10. FLOOD PROTECTION FACILITIES FOR TYPE 1 AND 2 STREAMS: The site does not contain or abut a type 1 or 2 stream. 11. GEOTECHNICAL ANALYSIS AND REPORT: The.proposed detention pond does not require a geotechnical analysis. ' 12. SOILS ANALYSIS AND REPORT: The soils underlying the site have been mapped by the Soils Conservation Service. 6 •r•■• + r • •)� r `i`1i ,�, :M� ;•7.., (A A • • , +_ •v. •�:; ( ,►�1;• li �� r ,c a ` wbwrlt 'G' 'Y�"y`'M►t��' : �r • 'F�'. 1,� � .��FJ{'.. 1 '�rf r�, ua,� • •I• • • f. .� I , �1.I 7� • 1. ,f •�IAr �.,,', l,• ,.,.' . I ✓� • rr • J' •• a f , • �Vr i wf',. c �• its r rNE r • • . • � ;� r .f, f, � Y„�` V ' ;�, ..,lire°,�,;,� rig ON • • �� LLI Olm ./ ,:lt'` fir' I�- a !� 1 „�;�.� ■.' ••■• • r. .• _• • • • • :� �. Q� W a r J f��C �•. 0 f"I :1yV �i��r_� •• • � + iJtb��� :■ Sol a ,�;; c r, `3` ``'yy�`',';f•,t�t.: . .fit+�}•�lid. .. •�;; II1 I .♦tiw ' �. . • � `1 ' �- ONJ�A� rill ••+ • LLI ` •• :< t3r : • t J: .. • ', A si .. .Y 0� it.A S. J . LLI ,,�.3:'l,i'.•....- ..�Y:. .L °ter�•L r • •• ..�. 1.�ic l' � �_• �.� ,Ct�; � .••.may. } t1�j.� kY r `•„�' r -•e r � � r'� ''%.' .4d .j.'t', .` 'S .\'.'3't�r.�ye.�,'��.�.':1'�f�,1i� +�•71.r"✓.�:. yjtLy4: •' �•'d �. M •• 1 • wo o r 1 ' TIR SECTION IV. RETENTIONMETENTION ANALYSIS AND DESIGN ' Existing Site Hydrology (Part A) To analyze the existing hydrology, the project site and surrounding tributary areas were considered, to determine if any offsite flows affect the site and how the combined flows affect the site and surrounding areas. The project has a total of approximately 12.25 acres. The proposed development consists of approximately 3.9 acres(Basin EX. and Basins A& B) and ' the remaining 8.35 acres(Basin R) will remain in its current state. The upstream area has two basins consisting of 7 acres(Basin U) and 11 acres(Basin O), that combine with site flows to a common point along Talbot Rd. approximately 60 feet north of the south property line where it crosses to the west via the previously mentioned 8" culvert. The site and the surrounding basins consist of heavy brush, grasses and trees on Alderwood, Type C resulting in a CN of 85 used for all. The times of concentration and travel ' time for each basin are shown in the attached Basin Summaries. (See attached drainage maps) The impervious and pervious area of lots will drain to the proposed detention system. To compensate for the bypass area, the detention system release rate will be restricted to ensure ' that the flow leaving the entire site during the developed storm events is equivalent to the existing rates. The area of the detention pond will be increased by 30 percent per the KCSWDM. The orifices were sized for the pond before the 30 percent increase. Calculations ' are provided below for the release rate and detention volume. Approximately 7 acres of offsite area is tributary to this site. The flow from the off-site area will be conveyed around the developed area. ' The following are the precipitation rates used for the calculations. P2 =2.00 inches P10 =2.90 inches P 100 = 3.90 inches ' Developed site Hydrology(Part B) A detention pond is proposed to limit peak runoff to the pre-developed peak rates for storm events up to and including the 100 year 24 hour storm and will be adjusted for a small area of bypass flows. This will assure that post-developed flows will be at or below existing levels. The supporting calculations and analysis are included in this report. The proposed development consists of 48 Single and multi-family units, a new roadway (S. 51 st Court), driveways, and lawn area. All of these change the runoff factor considerably and will require detention facilities. The developed area of the site comprises about 3.9 acres, this is the area used for determining the size of the detention facility. About 3.7 acres will flow to the R/D pond and 0.2 acres will bypass. The CN values used for developed flows are 86 for pervious and 98 for impervious surfaces. 7 ' Hydrologic Analysis Part C The conveyance systems throughout the site were sized using the 25 year/24hour storm. The capacities and flow rates are within the City's requirements. The minimum pipe size for mains is 12" and for roof/footing drains 6". The area of the property to the east that is not to be developed (8.35acres), and the 7 acre upstream basin will be conveyed around the site ' in a ditch and pipe system sized with enough capacity to carry the 25 year storm at a minimum. The 11 acre offsite area to the north will be collected just north of the site on Talbot Road and conveyed south along the site to the replaced existing culvert where they will flow to the west ' in a new 18" culvert as proposed on the City's plans for Talbot Road South. Flows will be conveyed to the retention/detention pond at the west central portion of the site in the ' conveyance system. The retention/detention system is sized to detain flows to match the events up to the 100 year developed storm. Flows leaving the pond will be adjusted to ensure the total flows ' leaving the site under Talbot Road will be at or below the existing flow rates. An overflow structure will be provided just above the 100 year water surface and a separate emergency overflow structure will be provided just above the overflow elevation as required. ' As a part of the R/D pond System, a Bio-filtration Swale is provided to filter low flows. The onsite conveyance system brings site flows to a manhole just before the bio-swale that contains an orifice sized to allow the water quality storm flow rate to go to the bio-Swale. The ' remainder flows will be diverted to the bottom of the R/D pond. Under this scenario, the required bio-filtration is achieved and flows are conveyed to the R/D pond. The bio-filtration swale is designed to be above the 2 year water surface, and during the 100 year storm the water surface is approximately 0.53 feet above the bio-swale for a brief period of time. This design allows the higher storm depths in the pond to flow higher than the bio-swale without causing damage due to high flow rates, i.e., erosion, by ponding slowly above. ' Retention/Detention System ,Part D) (See attached sketches and calculations.) The proposed R/D system was sized for storm events up to the 100 year 24 hour storm ' and adjusted for the bypass portion of flows to maintain flows at or below existing or pre-developed flow rates. Summary of flow rates (cfs) from the 3.9 acre area of development: Storm Event Pre-Dev. Post-Dev. Bypass Flow 2 yr 0.50 1.36 0.06 !0yr 1.10 2.19 0.10 100yr 1.84 3.14 0.14 Storm Event Allowed Release Rates Actual Release Rate Net Change In Flows ' 2yr 0.44 0.40 -0.10 l0yr 1.00 0.83 -0.17 100yr 1.70 1.48 -0.22 ' Summary of Total flows from the entire Tributary Basin to the cross-culvert on Talbot Rd S. Storm Event Pre-Dev. Flow Rate Post Dev-Flow Rate Net Change in Flows ' 2yr 3.66 3.55 -0.11 l0yr 8.04 7.46 -0.58 100yr 13.49 12.70 -0.79 8 File Basin Hydrogr-aph Storage Discharge Level pool 2 hP1N1111'1; A s s o c i a t e s ' 3 3lease 2 .0 -SAdd/subt hydro 3 3Divert flow 3 4 p18 LIST OF HYDROGRAPH VALUES 31-IYD PEAK PEAK TOTAL HYD PEAK PEAK TOTAL 3 RATE TIME VOLUME NO. RATE TIME VOLUME 3 3 1 A-1,'0we� 'z 0. 44 480 O. 26 11 2 0.06 480 0 . 02 3 2 to 1 .00 490 0 . 49 V-rZ-' 21"` e5 12 10 0. 10 480 0 . 04 i )e-- 3 3 100 1 . 70 480 0�77 13 1Z 0 . 14 4RQ.�,_ O _ OS Cam"' 3 '3 4 2 1 .36 470 0 . 44 F WW 14 3 3 5 2 . 19 470 0. 69 O -G-S 15 3 �O0 3 . 14 470 0 .99 16-- 3 3 7 Z 0 . 40 540 O. 4 �uA�-eel,-17 _43 3 8 f Q 0 .83 520 U .69�P-�csS w+�ji 18 3 9 1 pb___.1_.-48 10 0 . 99 91P6T �K,To 'l 0 . 50 490 0 . 26 _ � �i9 10 1 . 10 480 0 . 49 �Lp�5 3 ' 10 20 (pU 1 .e4 480 O . 7 7ryopA pl:U�A'Qe—,� TMMMMh1MrIP1MMMMMrlhlMhll"IMhJhIMMMr1MMMMMMMMrJMMMMMMMMMMMMMMMMMI`1MrIP1MP1MMhlMMMMIIhlMP1MMl`>hlhlMM>�vailable Memory remaining : 148528 bytes urrent Data Set Name : \SUMMITPK File Basin Hydrograph Storage Discharge Level pool 2 P'1MMMMP1P'IP1MP'IPIPIMMP1P18D A s s o c i a t e s ' > ;lease 2.0 3Add/subt hydro 3 3Divert flow 3 4 MMrIMMMMP1r1MrIMP1MMMMPIMMMMMMMMMMr11-IMMMP1MMr1rlMMMl1MMMMMMrIMMP1PIMMMMMP1rIMMMMr1MMMP1MPil'1Mr1M8 3 LIST OF HYDROGRAPH VALUES 3 3HYD PEAK PEAK TOTAL HYD PEAK PEAK TOTAL 3 3NO. RATE TIME VOLUME NO. RATE TIME VOLUME 3 3 1 Z 0.44 460 0.26 ��"�� 11 3.66 480 2.00 EtC ST 3 2 10 1 .00 480 0.49 P- 12 8.04 480 3 .79 Flat)S 3 ' 3 3 �oO 1 .70 490 0.77 � 13 13.49 480 5.97 3 3 4 2 1 .36 _- 470 J~ O. 44�VE,0 14 3. 55 480 2.21 w 2 3 3 5 10 2 . 19 470 0.69 15 7.46 490 4 .03 j�tip 3 3 6 _10U_3. 14 470 0.99 l �N� 16 12. 70 480 6.24 cA.-.�kYreU(, 3 7 b-- 3 7 0.40 540 O.44 f�=LrAsi PAi�17 z� _ 4.gO _______L �pC-v:����, S 3 3 8 i v 0.83 520 0 .69 18 9 . 18 480 4 .03 �0tK7T10�J3 3 9 1 .48 510 0.99 _ 19 14,. 84 480 6.24 3 1 10 20 3 TMMPIMPIMMMPIPIPIMMMM /PI MMMMMMMMMMMM/+�MMMMMMMMMM IMMrlrIMrIMMP1PIMMMMPiP MMMMMMMMMPIMMMM: P20p01.En 21D Po ajP w 13o ry "F0 f-4 L.. 4f L W S T-v vailable Memory remaining : 148529 bytes 04-7 urrent Data Set Name: \SUMMITPK C,(�t�'(/ -� C�A(\) E c N LO LO i t�t%yc-w p e� mac , `o , 00 �3� File Basin Hydrograph Storage Di--c 11arK.e Level pool TRIAD Associates 2MMMMMMMMMMMMMIvJMMMf3 31 v1rJM1 vJl vJMI vlMl vJrJMMMrJl vlrJMrJI v11 rJrJMMMMMt�1MMMM1 vJMMMMMMMMMMMMMMMMMMrJMMMMMMMM�IMMI vll rIMMMMMMMMI�1MMM�' 3 ROUTING COMPARISON TABLE 3 y MATCH INFLOW STO DIS PEAK PEAK OUT 3 3 DESCRIPTION PEAK PEAK No. No . STG OUT HYD 3 =--------------- 0 .45 1 .36 C1 C1 147 . 35 0. 45 17 3 ' 310 1 . 01 2. 19 C1 C1 146.05 0. 93 18 3 0100 1 .71 3. 14 C1 C1 146 . 58 1. 37 19 3 3 3 3 J 3 3 __________________>Dnne<====_______________= Press any key to exit Ti'7rIrJ1 vIl JrJI vJMI`JI�i1�9MM1tiJ1tiJ1 Jrll vJMMMMI vJrJMrIMMrJMMMMI JMI uJMMMMMMMMMMMMMMMMMMMMMMMMI vIMMMMMMMMMMMMMMM� Available Memory remaining: 148528 byte-. urrent Data Set Name : \SUMMITPK File Basin Hydrograph Storage Discharge Level pool ' 21�Jf11vJ1vJl1111vJIvJIvJIvJrJfiMlllvJlvlMMrJIvJIvJMB 3 3 3Rectangular vault 3 3Trapezoidal basin 3 ' ,3Underground pipe 3 ti,to list 3 t �ustom file 3 ' 3rJ1JrJIvIr11�JMM1tiJ1`J1ti11tiJrJ1�JMIIMrJIvJMMMMMIvIMIVIlI1rJrJI�JM1�JrJM1v1M1�JrJ1~IIyJIvJrT�MhJMMr11vJMMrJf11`JMIvJ1�91`IMi�.FMIIMMlJ3' 3 CUSTOM STG-STO LIST 3 3 STORAGE STRUCTURE ID: Ci 3 '5NAME: 3 ' 31NCREMENT: 0. 10 3 9 t 3 STAGE AREA sf STAGE AREA sf 3 ' 31 : 145 .00 520 .00 6: 150. 00 6880 .00 3 32: 146.00 781 .00 7 : 0.00 0 .00 3 33: 147 .00 1309.00 8: 0 .00 0 .00 3 ' 34: 148 .00 3770.00 9: 0 .00 0.00 3 �75 : 149. 00 5590 .00 10: 0.00 0.00 3 3 J 3PGUP PGDN F2 : AREA F3: GET F6: Delete F10: Exit 3 ITIvJMMMMIvJMMMMMMMMMMMrJrJMMMMMMMMMMMrIMMMrIMMMMIvIM1vJrIMMMMIvJMIvJIvJMMMIvJMMMMMMMMMMM_� vailable Memory remaining: 148528 bytes Current. Data Set Name: \SUMMITPK �N ' Vp W tOtg- 0LWMA-CZL4 _ �6 k- � QUir2�t�_ � (oZ37-606F 7` Le Vb(,LAAA c,f= 2;,48 GF _ f ' File Basin Hydrograph Storage Discharge Level pool TRIAD Associates 21v11~IrIMMMMMrIMMMriMrIMM3 3MMMMMMMMMMMMMMMMMMMMMMMMrIMMMMI�IMMMM1v1MM1vIM1vIMMIvIMrIMM1�IMM1�IMrIMMMMMMMIIMMMMhIMr11+ 8 3 ROUTING COMPARISON TABLE 3 ' 3 MATCH INFLOW STO DIS PEAK PEAK OUT 3 3 DESCRIPTION PEAK PEAK No. No. STG OUT HYD 3 _____________________________________________________________________ 3 32 0. 45 1.36 Al Al 147.37 0.45 17 3 310 1 .01 2. 19 Al Al 148.25 1.01 18 3 3100 1 .71 3. 14 Al Al 149.00 1 .71 19 3 3 3 3 3 3 3 3 3 ' 3 3 3 3 3 3 3 3 TMMMMMr11vIMMIvIMM1�IMrIMMI°IMMrIMMM1�IrIMM"IMrI1vIMIvIMMrIrIMrIMrIMMMMMI~IMMMMMMMMMMMMMMMMr�lIMMMMMMM> Available Memory remaining: 148528 bytes �urrent. Data Set Name : \SUMMITPK File Basin Hydrograph Storage Discharge Level pool ' 2r11�IMM�11�11rIMMMrIr1MrIMMMMrItjPjPYq 3 3 3Rectangular vault 3 3Trapezoidal basin 3 ' 5Underground pipe 3 3 M��IMMrIr11 r1MrIMMr11 rllIMMMMMrIMpll Vlrlrll�l�`�IMMMrIMMMrI1�IrIrIMMMMrIr1Eti1MMr11�IrIMI V11`11'IMB 3 TRAPEZOIDAL BASIN 3 ' 3 STORAGE STRUCTURE ID: Al 3 3 3 3Name: POND W/O 30% SAFTEY 3 3Length. . . . . . . . . . . 56.70 Width. . . . . . . . . . . 10.00 3 ' 3 Length Sslope 1: 3.00 Width Sslope 3: 3.00 3 3 Length Sslope 2: 3.00 Width Sslope 4: 3.00 3 3Infiltration Rate. . : 0.00 (min/in) 3 ' 3Starting Elevation. : 145.00 3. Max Elev of Basin. . : 149.00 3 3Stage-Sto Increment : 0. 10 3 ' 3Structure Vol (of) . : 6237.60 C 3 Ac-ft. : 0. 14 J?r WI30io � 3 3 3PGUP PGDN F3: Get F6: Delete F10: Exit 3 v TMMMr11rIrIMMMMMMMMMMMrIMrIMMrIMMMMMMMMIvIMMMMMMMMMMMMMMMMMMMMMMMM> Current Data Set Name: \SUMMITPK �D ' File Basin Hydrograph Storage Discharge Level pool TRIAD Associates 2Itti111r111M1J11M1�11II1iti31�1r1t�IMo 3N11Y1r"11r1r°I�1Mr1rIM1�IMrlr11.��tilrlrlMr1r11�IMMrll�1111"IMI�1Mhlr11�JE"11�1M1�Ir11�1Mr1MMMMIIMI�11�ll�IMMI�I1�IMh11�IM1'1MrIMMtIMM1''�11�Ir1M8 3 ROUTING COMPARISON TABLE 3 ' 3 MATCH INFLOW STO DIS PEAK PEAK OUT 3 3 DESCRIPTION PEAK PEAK No. No. STG OUT HYD3 L ___ -----------------------._----_-------_-__-__----------___------_ 3 ' 02 0. 45 1.36 C1 C1 147.35 0. 45 17 3 310 1 .01 2. 19 C1 C1 148.05 0.93 18 3 3100 1 .71 3. 14 C1 C1 148.58 1. 37 19 3 n L,3 LT L� 3 3 3 LY � 3 3 3 3 ' 3 3 3 �'S TrIMMrIrIr1MMMMMMtIMMrIMMMr11�11IMrIMMMMMMMI�IMMMMMMMMMMMMMMMMMMMMMM1r1MMMMMMMMMMMMMMMMMM> Available Memory remaining: 122632 byte: �urrent Data Set Name: \SU�IMITPK File Basin Hydr•ograph rage Discharge Level pool ' 3rlMtlrlrfrlMMMM�1r1�tiJ1�JMMI�IMMr1MMr11IlIr1MrJMlJ"IMMMMMMMMMMMMMMMMrIMMMr1r1rJMMMMrIMMMMMB 3 MULTIPLE ORIFICE L7 3 DISCHARGE STRUCTURE ID:CI 3 3 3 X ame: 3 /Peak Dsgn Release Rate: 0.00 cfs Orif /flow/elev 3 30rifice Coefficient . . . : 0. 62 Dia ( in)/cfs/ ft 3 ' 3Lowest Orifice Dia ( in) . . : 3.28 3.28 0. 65 cfs 3 3hl: Outlet to Znd Orifice: 2.50 147 .50 ft 3 *3Second Orifice Dia ( in) . . : 4.54 4. 54 0.88 cfs 3 3h2: Znd to 3rd Orifice. . . . 0.90 148. 40 ft 3 /Third Orifice Dia ( in) . . : 4. 57 4. 57 0.72 cfs 3 3h3: 3rd to 4th Orifice. . . : 0.00 3 3Fourth Orifice Dia ( in) . . : 0.00 3 ' 3h4: 4th to 5th Orifice. . . : 0.00 3 Loop Orifice Dia ( in) . . . 0.00 3 3 3 /Elevation of Lowest Orifice. . . . . 143.00 3 LJutlet Elevation. . . . . . . . . . . .. . . . 145.00 3 3Max Elev Above Outlet. . . . . . . . . . : 150.00 3 /Stage-Disch Increment. . . . . . . . . . . 0. 10 3 l3 L v,--jPGUP PGDN F3: Get F6: Delete F10: Exit 3 Cu TMrIr1MMMMA11�MrIMrIhIrIMMrIMMMi"Ir1MMI�IMMIIMMMMMMMMMMMMI�IMMMr1MMMr1MMMr1I�MMI�IMMMr1IYIMMM> ' �G7 6/14/s4 TR.IAD Associates rage i ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS. & BIOFILTRATION SWALE CALCS. ---------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY ' BASIN ID: AD10 NAME: 10YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2.00 Acres BASEFLOWS: 0.00 cfs; RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 2.90 inches AREA. . : 0 .80 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 7.33 min IMPERVIOUS AREA ' ABSTRACTION COEFF: 0.20 AREA. . : 1 . 20 Acres CN. . . . : 98.00 TcReach - Sheet L: 300.00 ns:0.0500 p2yr: 2.00 s:0.0900 ' TcReach - Channel L: 35.00 kc :42.00 s:0.0800 TcReach - Channel L: 140.00 kc :42.00 s:0 . 1250 TcReach - Channel L: 60.00 kc: 42.00 s:0 .0050 PEAK RATE: 1. 15 ofs VOL: 0.37 Ac-ft TIME: 480 min BASIN ID: AD100 NAME: 100 YR DEV. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2.00 Acres BASEFLOWS: 0 .00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION . . . . : 3.90 inches AREA. . : 0.80 Acre: ' TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 7.33 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . . 1 .20 Acres CN. . . . . 98. 00 TcReach - Sheet L: 300.00 ns:0.0500 p2yr: 2.00 s:0 .0900 TcReach - Channel L: 35.00 kc: 42.00 s:0.0800 TcReach - Channel L: 140.00 kc: 42.00 s:0. 1250 ' TcReach - Channel L: 60.00 kc: 42.00 s:0 .0050 PEAK RATE: 1.64 cfs VOL: 0 .53 Ac-ft TIME: 480 min BASIN ID: AD2 NAME: 2YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2.00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 2.00 inches AREA. . : 0.80 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 7.33 min IMPERVIOUS AREA ' ABSTRACTION COEFF: 0.20 AREA. . : 1 .20 Acres CN. . . . : 96.00 TcReach - Sheet L: 300.00 ns:0.0500 p2yr: 2.00 s:0.0900 TcReach - Channel L: 35.00 kc:42.00 s:0.0800 ' TcReach - Channel L: 140.00 kc:42.00 s:0. 1250 TcReach - Channel L: 60.00 kc: 42.00 s:0 .0050 PEAK RATE: 0.72 cfs VOL: 0.23 Ac-ft TIME: 460 min ' 6/14/94 TRIAD Associates page 2' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS_ BASIN SUMMARY=====_____________________-_ ' BASIN ID: AD3 NAME: 1/3 2YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2.00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 0. 67 inches AREA. . : 0.80 Acres TIME INTERVAL. . . . : 10.00 min CN. . _ . : 86.00 ' TIME OF CONC. . . . . : 7.33 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1 . 20 Acres CN. . . . : 93. 00 ' TcReach - Sheet. L: 300.00 ns:0.0500 p2yr: 2.00 s:0. 0900 TcReach - Channel L: 35.00 kc: 42.00 s:0.0800 TcReach - Channel L: 140.00 kc:42.00 s:0. 1250 TcReach - Channel L: 60.00 kc: 42.00 s:0.0050 ' PEAK RATE: 0. 15 efs VOL: 0.05 Ae-ft TIME: 480 min BASIN ID: BD10 NAME: 10YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 .70 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . _ . ; 2 .90 inches AREA. . : 0 . 64 Acres TIME INTERVAL. . . . : 10. 00 min CN. . _ . _ 86.00 TIME OF CONC. . . . . : 4.87 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 .20 AREA. . : 1.06 Acres ' CN. . . . : 98.00 PEAK RATE: 1 .07 cfs VOL: 0.32 Ac-ft TIME: 470 min BASIN ID: BD100 NAME: 100YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1.70 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3.90 inches AREA. . : 0.64 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 4.87 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1.06 Acres CN. . . . : 98.00 TcReach - Sheet L: 190.00 ns:0.0500 p2yr: 2.00 s:0 . 1050 TcReach - Channel L: 100.00 kc: 42.00 s:0.0600 TcReach - Channel L: 50.00 kc:42.00 s:0. 1400 TcReach - Channel L: 120.00 kc: 42.00 s:0.0850 TcReach - Channel L: 65.00 kc: 42.00 s:0.2000 PEAK RATE: 1 .52 efs VOL: 0 .45 Ac-ft TIME: 470 min 6/14/94 TRIAD Associates page 3 ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION ,SWALE CALCS. ' BASIN SUMMARY=====________-______-_______ BASIN ID: BD2 NAME: 2YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1.70 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.00 inches AREA. . : 0. 64 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 4.67 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1 .06 Acres CN. . . . . 98.00 TcReach - Sheet L: 190 .00 ns:0.0500 p2yr: 2.00 s:0. 1050 TcReach - Channel L: 100.00 kc:42.00 s:0.0600 TcReach Channel L: 50.00 kc:42.00 s:0. 1400 TcReach - Channel L: 120.00 kc:42.00 s:0.0850 ' TcReach - Channel L: 65.00 kc:42.00 s:0.2000 PEAK RATE: 0.67 cfs VOL: 0.20 Ac-ft TIME: 470 min BASIN ID: BD3 NAME: 2YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1.70 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 0 . 67 inches AREA. . : 0. 64 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . . 4.87 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1 .06 Acres 1 CN. . . . : 98.00 TcReach - Sheet L: 190.00 ns:0.0500 p2yr: 2.00 s:0 . 1050 TcReach - Channel L: 100.00 kc: 42.00 s:0.0600 ' TcReach - Channel L: 50.00 kc:42.00 s:0. 1400 TcReach - Channel L: 120.00 kc:42.00 s:0.0850 TcReach - Channel L: 65.00 kc:42.00 s:0.2000 PEAK RATE: 0. 14 cfs VOL: 0.05 Ac-ft TIME: 470 min BASIN ID: BP10 NAME: 10YR BYPASS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0.20 Acres BASEFLOWS: 0.00 of-- RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.90 inches AREA. . : 0. 12 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . : 18.35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.08 Acres CN. . . . . 98.00 TcReach - Sheet L: 400.00 ns:0. 1500 p2yr: 2.00 s:0. 1200 ' PEAK RATE: 0.09 cfs VOL: 0.03 Ac-ft TIME: 480 -min B�" 6/14/94 TRIAD Associates page 4 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. ' BASIN SUMMARY======______________________ ' BASIN ID: BP100 NAME: 100YR BYPASS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0.20 Acres BASEFLOWS: 0 .00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3.90 inches AREA. . : 0 . 12 Acres TIME INTERVAL. . . . : 10.00 min CN- - - - : 86.00 ' TIME OF CONC. . . . . : 18. 35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.08 Acres CN. . . . : 98.00 ' TcReach - Sheet L: 400.00 ns:0. 1500 p2yr: 2. 00 s:0. 1200 PEAK RATE: 0. 13 cfs VOL: 0.05 Ac-ft TIME: 480 min BASIN ID: BP2 NAME: 2YR BYPASS ' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0.20 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 2.00 inches AREA. . : 0. 12 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC. . . . . . 18.35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0 .08 Acres ' CN . . . . : 98.00 TcReach - Sheet L: 400.00 ns:0. 1500 p2yr: 2.00 s:0 . 1200 PEAK RATE: 0 .05 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: EX10 NAME: 10 YEAR EX. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 3.90 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.90 inches AREA. . : 3.90 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 ' TIME OF CONC. . . . . : 23.08 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres CN. . . . . 98.00 PEAK RATE: 1 . 10 cfs VOL: 0.49 Ac-ft TIME: 480 min �Z 6/14/94 TRIAD Associates page 5 ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. BASIN SUMMARY ' BASIN ID: EX100 NAME: 100 YEAR EX. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 3.90 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3.90 inches AREA. . : 3. 90 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 ' TIME OF CONC. . . . . : 23.08 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0. 00 Acres CN . . . . : 98. 00 ' PEAK RATE: 1.84 cfs VOL: 0.77 Ac-ft TIME: 480 min BASIN ID: EX2 NAME: 2 YEAR EX. ' SBUH METHODOLOGY TOTAL AREA. . . . . . • 3.90 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.00 inches AREA. . : 3.90 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 TIME OF CONC. . . . . : 23.08 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres ' CN. . . . : 98.00 ToReach - Sheet L: 300.00 ns:0.2400 p2yr: 2 .00 s:0. 1330 TcReach - Shallow L: 210.00 ks:5.00 s:0. 1330 TcReach - Channel L: 180.00 kc: 17 .00 s:0.0500 ' PEAK RATE: 0. 50 cfs VOL: 0.26 Ac-ft TIME: 480 min ' BASIN ID: 010 NAME: 10YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 11.00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.90 inches AREA. . : 11 .00 Acres TIME INTERVAL. . . . : 10.00 min CN- - - - : 85.00 TIME OF CONC. . . . . : 36.98 min IMPERVIOUS AREA ' ABSTRACTION COEFF: 0.20 AREA. _ : 0.00 Acres CN. . . . . 98. 00 TcReach - Sheet L: 300.00 ns:0. 1500 p2yr: 2.00 s:0.0600 ' TcReach - Shallow L:1700.00 ks:5.00 s:0. 1200 TcReach - Channel L: 200.00 kc: 17.00 s:0.0200 PEAK RATE: 2.51 cfs VOL: 1 .38 Ac-ft TIME: 480 min g 6/14/94 TRIAD Associates page 6y ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS BIOFILTRATION SWALE CALLS_ ' BASIN SUMMAkY=====_____-_________-_______ ' BASIN ID: 0100 NAME: 100YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 11.00 Acres BASEFLOWS: 0 .00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION_ . . . : 3.90 inches AREA. . : 11.00 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85 .00 ' TIME OF CONC. . . . . : 36.98 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. _ : 0 .00 Acres CN. . . . : 98.00 ' TcReach - Sheet L: 300.00 ns:0. 1500 p2yr: 2.00 s: 0.0600 TcReach -Shallow L: 1700. 00 ks: 5.00 s:0. 1200 TcReach - Channel L: 200.00 kc: 17.00 s:0.0200 PEAK RATE: 4.24 cfs VOL: 2. 17 Ac-ft TIME: 480 min BASIN ID: 02 NAME: 2 YEAR EX. ' SBUH METHODOLOGY TOTAL AREA. . . . . . . . 11 .00 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 2.00 inches AREA. . : 11 .00 Acres TIME INTERVAL. . . . . 10.00 min CN. . . . . 85.00 TIME OF CONC. . . . . . 36.98 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres ' CN. . . . : 98.00 TcReach - Sheet L: 300.00 ns:0 . 1500 p2yr: 2.00 s:0 .0600 TcReach - Shallow L: 1700 .00 ks:5.00 3:0. 1200 ' TcReach - Channel L: 200.00 kc: 17 .00 s:0.0200 PEAK RATE: 1 . 14 cfs VOL: 0.73 Ac-ft TIME: 490 min BASIN ID: R10 NAME: 10 YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 8. 35 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.90 inches AREA. . : 8.35 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 TIME OF CONC. . . . . : 33. 19 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres CN. . . . . 98.00 TcReach - Sheet L: 300.00 ns:0.4000 p2yr: 2.00 s:0. 1667 TcReach - Shallow L: 710.00 ks:5.00 s:0.2085 PEAK RATE: 2.00 cfs VOL: 1 .05 Ac-ft TIME: 480 min 8 l4� ' 6/14/94 TRIAD Associates page 7 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. BASIN SUMMARY=====_______________________ ' BASIN ID: R100 NAME: 100YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 8. 35 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3.90 inches AREA. . : 8. 35 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 ' TIME OF CONC. . . . . : 33. 19 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0.00 Acres CN. . . . : 98. 00 ' TcReach - Sheet L: 300.00 ns:0.4000 p2yr: 2 .00 s:0. 1667 TcReach - Shallow L: 710. 00 ks: 5.00 s:0.2085 PEAK RATE: 3.38 cfs VOL: 1. 65 Ac-ft TIME: 480 min BASIN ID: R2 NAME: 2 YEAR EX. ' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 8. 35 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 2.00 inches AREA. . : 8 . 35 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 TIME OF CONC. . . . . . 33. 19 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0. 00 Acres ' T CN. . . . : 98. G0TcReach - SheetL: 300.00 ns:0. 4000 p2yr: 2 .00 s:0. 1667 TcReach - Shallow L: 710.00 ks: 5.00 s:0.2085 ' PEAK RATE: 0.91 cfs VOL: 0 . 55 Ac-ft TIME: 490 min ' BASIN ID: R25 NAME: 25 YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 8.35 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3.40 inches AREA. . : 8. 35 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 TIME OF CONC. . . . . : 33. 19 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . 0.00 Acres CN. . . . . 98.00 TcReach - Sheet L: 300.00 ns:0.4000 p2yr: 2.00 s:0. 1667 ' TcReach - Shallow L: 710.00 ks:5.00 s:0.2085 PEAK RATE: 2.68 cfs VOL: 1.34 Ac-ft TIME: 480 min 6/14/94 TRIAD Associates page 8 ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALLS. BASIN SUMMARY ' BASIN ID: U10 NAME: 10YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7.00 Acres BASEFLOWS: 0.00 cfs ' RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.90 inches AREA. . : 7 .00 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 65.00 TIME OF CONC. . . . . : 11 .77 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres CN. . . . : 98.00 TcReach - Sheet L: 300.00 ns:0.0600 p2yr: 2. 00 s:0 .0500 TcReach - Shallow L: 330.00 ks: 11 .00 s:0.0750 PEAK RATE: 2.43 cfs VOL: 0 .88 Ac-ft TIME: 480 min BASIN ID: U100 NAME: 100YR EX ' SBUH METHODOLOGY TOTAL AREA. . . . 7.00 Acres BASEFLOWS: 0 .00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA ' PRECIPITATION. . . . : 3.90 inches AREA. . : 7 .00 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85.00 TIME OF CONC. . . . . . 11.77 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 .20 AREA. . : 0 .00 Acres ' CN. . . . : 98. 00 TcReach - Sheet L: 300 .00 ns:0.0600 p2yr: 2.00 s:0.0500 TcReach - Shallow L: 330.00 ks: 11.00 s:0.0750 ' PEAK RATE: 4.02 cfs VOL: 1.38 Ac-ft TIME: 480 min ' BASIN ID: U2 NAME: 2 YEAR EX. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7 .00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2.00 inches AREA. . : 7 .00 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 85 .00 TIME OF CONC. . . . . : 11 .77 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 0.00 Acres CN. . . . . 98.00 TcReach - Sheet L: 300.00 ns:0.0600 p2yr: 2.00 s:0.0500 ' TcReach - Shallow L: 330.00 ks: 11.00 s: 0.0750 PEAK RATE: 1 . 13 cfs VOL: 0.46 Ac-ft TIME: 480 min r 6/14/94 TRIAD Associates page 9 ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. ' BASIN SUMMARY=====________-_____________= ' BASIN ID: U25 NAME: 25 YR EX SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7 .00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3. 40 inches AREA. . : 7.00 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 85.00 TIME OF CONC. . . . . : 11 .77 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA_ . _ 0.00 Acres CN. . . . . 98.00 ' TcReach _ Sheet L: 300 .00 ns: 0.0600 p2yr: 2.00 s:0.0500 TcReach Shallow L: 330. 00 ks: 11 . 00 s:0.0750 PEAK RATE: 3.21 cfs VOL: 1 . 13 Ac-ft TIME: 480 min 1 r 1 r 1 1 r r r r r 1 gN ' 6/14/94 TRIAD Associates page i0 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. STAGE STORAGE TABLE====__-_____________-____ ' TRAPEZOIDAL BASIN ID No. Al Description: POND W/O 30% SAFTEY Length: 35. 00 ft. Width: 10.00 ft. ' Side Slope 1 : 3 Side Slope 3: 3 Side Slope 2: 3 Side Slope 4: 3 Infiltration Rate: 0.00 min/inch STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <--- STO JAGE----> STAGE <----STORAGE----> ( ft) ---of--- --Ac-Ft- ( ft) ---of--- --Ac-Ft- ( ft ) ---cf--- --Ac-Ft- (ft) ---of--- --Ac-Ft- 146.00 0.0000 0.0000 147 . 30 709. 51 0 .0163 148 . 60 203 0 .0467 149 .90 4130 0.0948 146. 10 36. 362 0.0008 147 . 40 787. 53 0. 0181 148 .70 Zi6 5 0 .0497 150.00 4328 0.0994 146.20 75 . 496 0.0017 147 . 50 869 .25 0.0200 148 . 80 230 0 . 0528 150 . 10 4531 0 . 1040 146. 30 117 . 47 0.0027 147 . 60 954.75 0 .0219 148 . 90 244 3 0 . 0561 150 .20 4740 0. 1088 146. 40 162. 37 0.0037 147 .70 1044 0.0240 149 . 00 258 0 .0594 150. 30 4955 0 . 1138 146. 50 210.25 0.0048 147.80 1137 0.0261 149. 10 274 0 .0629 150. 40 5176 0 . 1188 146. 60 261 . 19 0.0060 147 .90 1235 0.0283 149. 20 289 0 . 0665 150. 50 5402 0. 1240 146.70 315. 27 0.0072 148.00 1336 0.0307 149 . 30 305 0 .0702 150 . 60 5635 0. 1294 146.80 372.54 0.0086 148. 10 1441 0 .0331 149. 40 322 2 0 . 0740 150.70 5873 0. 1348 146.90 433. 10 0.0099 148.20 1551 0.0356 149 .50 339 0 . 0779 150.80 6118 0. 1404 147.00 497 .00 0.0114 148.30 1665 0.0382 149. 60 356 0 .0819 150.90 6368 0. 1462 147 . 10 564.32 0.0130 148. 40 1783 0.0409 149.70 375 0 .0861 151.00 6625 0. 1521 147.20 635. 14 0.0146 148.50 1906 0.0438 149 . 80 393 0.0904 "0 6/14/94 TRIAD Associates ' SUMMIT PARK �d � 2 1 RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. STAGE STORAGE TABLE====_____________________ CUSTOM STORAGE ID No . Cl Description: STAGE <----STORAGE---- STAGE <----STORAGE----> STAGE <----STO GE----> STAGE <----STORAGE----> ( ft) ---cf--- --Ac-Ft- (ft ) ---of--- --Ac-Ft- ( ft) ---Of--- --Ac-Ft- (ft ) ---cf--- --Ac-Ft- 145.00 000 0.0000 146. 30 964. 00 0 . 0221 147 . 61*0 321 9 0 . 0739 148.90 8447 0. 1939 145. 10 65.050 0.0015 146. 40 1069 0 .0245 147 .70 347 0 .0797 149.00 8915 0.2047 145.20 130. 10 0.0030 146. 50 1173 0 .0269 147 .80 372 0 .0856 149. 10 9539 0.2190 145 .30 195. 15 0 .0045 146. 60 1278 0. 0293 147 . 90 398 0 .0914 149 .20 10162 0 .2333 145.40 260.20 0.0060 146.70 1382 0 .0317 148. 00 423 0.0972 149 . 30 10786 0.2476 145 .50 325.25 0.0075 146.80 1487 0. 0341 148 . 10 470 3 0. 1080 149. 40 11409 0.2619 145. 60 390.30 0.0090 146.90 1591 0. 0365 148.20 517 0. 1187 149.50 12033 0 .2762 145 .70 455. 35 0.0105 147 . 00 1696 0 .0389 148 . 30 563 0. 1295 149. 60 12656 0.2905 145 .80 520. 40 0.0119 147 . 10 1949 0. 0448 148. 40 610 0. 1402 149.70 13280 0.3049 145 .90 585 . 45 0.0134 147.20 2203 0 .0506 148. 50 657 0. 1509 149.80 13903 0.3192 146.00 650. 50 0.0149 147 . 30 2457 0.0564 148. 60 704 3 0. 1617 149.90 14527 0.3335 146. 10 755 .00 0.0173 147 . 40 2711 0. 0622 148.70 751 0. 1724 150.00 15150 0.3478 146.20 859. 50 0.0197 . 147 . 50 2965 0 . 0681 148. 80 797 9 0. 1832 6/14/94 TRIAD Associates page 13 ' SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. STAGE DISCHARGE TABLE====______-_____________ ' MULTIPLE ORIFICE ID No. Al Description: W/O 30% SAFETY FACTOR Outlet Elev: 145.00 Elev: 143.00 ft Orifice Diameter: 3. 2813 in. Elev: 147.50 ft Orifice 2 Diameter: 4.5352 in. Elev: 148.40 ft Orifice 3 Diameter: 4. 5703 in. STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISC ARGE---> STAGE <--DISCHARGE---> ( ft) ---cfs-- ------- (ft) ---cfs-- ------- ( ft) ---c:fs- - ------- (ft) ---cfs-- ------- 145.00 0000 146.30 0.3331 147. 60 0. 647 6 148.90 1 . 6382 145 . 10 0.0924 146.40 0. 3457 147 .70 0 .729 149 .00 1 .7070 145 .20 0. 1307 146.50 0 . 3578 147 .80 0 . 794 149 . 10 1 .7719 145 .30 0. 1600 146. 60 0 . 3696 147 .90 0 . 850 149 . 20 1 .8335 145 . 40 0 . 1848 146.70 0. 3809 148 .00 0.900 149.30 1 .8924 145 .50 0.2066 146.80 0. 3920 148 . 10 0. 946 8 149. 40 1 .9490 145. 60 0 . 2263 146.90 0. 4027 148.20 0.989 149 .50 2.0036 145.70. 0.2444 147 .00 0. 4132 148. 30 1 .030 149. 60 2.0564 145.80 0.2613 147 . 10 0 . 4234 146.40 1 . 068 149.70 2. 1076 145 .90 0.2772 147 .20 0. 4334 148. 50 1 . 284 149.80 . 2. 1573 146.00 0.2922 147 . 30 0. 4431 148. 60 1 . 393 2 149.90 2.2057 146. 10 0. 3064 147 .40 0. 4526 148.70 1 . 483 150.00 2 .2528 146.20 0 . 3201 147 .50 0. 4620 148.80 1 . 564 4 ' 6/14/94 TRIAD Associates 14 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. ' STAGE DISCHARGE TABLE====__________-_________ MULTIPLE ORIFICE ID No . C1 Description: Outlet Elev: 145.00 Elev: 143. 00 ft Orifice Diameter: 3.2800 in. Elev: 147.50 ft Orifice 2 Diameter: 4.5400 in. Elev: 148. 40 ft Orifice 3 Diameter: 4.5700 in. STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISC ARGE---> STAGE <--DISCHARGE---> ( ft) ---cfs-- ------- ( ft ) ---cfs-- ------- (ft ) ---ofs- ------- (ft) ---cfs-- ------- ------------------------------------------------------------------ 145.00 0.0000________ 146. 30 0.3329 147 . 60 0 . 647 6 148 .90 1 . 6391 145 . 10 0. 0923 146. 40 0.3454 147 .70 0 . 7219 149 .00 1 .7080 145.20 0. 1306 146. 50 0. 3576 147 . 80 -0) . 794 Q 149 . 10 1 .7728 145.30 0. 1599 146. 60 0. 3693 147 .90 0 . 850 149.20 1 .8345 145.40 0. 1846 146.70 0. 3807 148 . 0 ' 149.30 1 .8935 145.50 0.2064 146. 80 0 . 3917 143. 10 0 . 347 3 149 .40 1.9501 ' 145 .60 0.2261 146.90 0. 4024 148 . 20 0. 990 149.50 2.0048 145.70 0.2443 147 .00 0.4129 148 . .30 1 . 030 149 . 60 2.0576 145.80 0.2611 147. 10 0. 4231 148. 40 1 .069 149.70 2. 1088 145.90 0.2770 147 .20 0. 4330 148. 50 1 . 284 ' 149 .80 2. 1585 146.00 0.2920 147 . 30 0.4428 148. 60 1 . 394 0 149.90 2.2069 ' 146. 10 0.3062 147 . 40 0.4523 148.70 1 . 484 150.00 2.2541 146.20 0.3198 147 . 50 0 . 4616 146. 80 1 . 565 3 6/14/94 TRIAD Associate. page 15' 1 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & BIOFILTRATION SWALE CALCS. LEVEL POOL TABLE'SUMMARY =====_______-__________ ' STORAGE MATCH INFLOW -STO- -DIS- <-PEAK-J <--------DESCRIPTION-------- (cfs) (cfs) --id- ----id- `.-STAGES 17 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . 45 1 . 36 C1 Cl 147 . 315 2578.50 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .01 2. 19 Gi C1 14�8 . 05 4484.62 100 . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .71 3. 14 C1 Cl 143 . 58 6942.27 1 S s • low •���A�t� i �1 =_____ ___ _ _ ■ e . pub IN ► , r f i I � • o 00 z 1 '' Q O ♦ WETLAND { EXIST. HOUSE AND DRIVE (TYP.).-__. AREA TO BE DEVELOPED AC i -- --- S E�CisTtN�� GoND lTl o�5 �.D�-r�o��— , •� f♦ a ILI, ■ ww.gait ._� _ISS.; mile �._ � . � 44 JAL ra r� t • w • • I WONPi 11I I � � tt EE _ � • OMP v all for WIN i;jwfj � — , � � � Iwo Zs•• � -- Is .. ;Dpzlls [oil]. . . ��t��►jam ' TIR SECTION V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN (Please see attached calculations) ' This section includes an analysis of the proposed conveyance systems for the project. These include the storm drain pipes, the Bio-filtration swale and the ditch on the ' east side of the rockery walls. The storm drain system was calculated based upon the 25 year precipitation rate for the area. the analysis showed that the pipe system will convey the flows and in most ' cases have a lot of additional capacity available. The Bio-filtration swale was sized using the water quality precipitation rate (P2/3) and the criteria outlined in the drainage manual. This included a 200 foot length, 2% slope, and An N=0.35. The actual swale used was then adjusted to fit the site. This proposal shows the swale in the detention pond. The bottom of the swale is above the 2 ' year water surface of the pond and at the 10 year water surface. This design allows only the low flow to enter the swale and force all flows above to be diverted to the bottom of the detention pond. The calculation for the diversion structure is also included . 9 SUMMIT PARK ' PIPE SIZING CALCULATIONS LOCATION ( ( FLOW PIPE DATA 1 FROM TO AREA C £ AC TIME I25 TIME SLOPE LENGTH N DIA. Vact Vcap Q Qcap 17A 17 0.23 0.60 0.13 10.0 1.96 0.1 ( 1.50 20 1 0.012 12 73 17 16 0.10 0.60 0.18 10.1 1.95 0.3 ( 8.33 % 132 0.012 I 12 ' 7.02 4.20 0.25 1.15 14.20 � 0.35 � 11.15 � 16A 16 0.11 0.60 0.06 10.0 1.96 0.1 6.62 t 34 0.012 12 4.40 12.66 0.11 9.94 SUMMATION OF AREA FROM 16A 17 TIME FROM 17 16 15 0.09 0.60 0.28 10.4 1.92 0.3 9.20 % 125 0.012 12 7.70 14.92 0.53 11.72 � 15A 15 ( 0.20' 0.60 0.11 10.0 1.96 0.4 1.77 % 82 0.012 12 3.24 6.59 0.21 5.14 SUMMATION OF AREA FROM 16 15A TIME FROM 16 15 14 0.16 0.60 0.48 10.7 1.89 0.2 6.63 9 120 0.012 12 8.01 95 14 10 0.00 0,60 0.47 10.9 1.87 0.0 28.20 1 15 0.012 12 26.15 ( 0.90 0.53 ' � 13.49 � 26.15 � 0.87 � 20.53 � 13A 13 0.27 0.60 0.16 10.0 1.96 0.2 0.54 t 26 0.012 12 13 12 0.60 0.60 0.52 10.2 1.94 0.2 13.67 % 119 0.012 I 12 I 0.50 3.20 1.00 2.29 12 11A 0.28 0.60 0.68 10.4 1.92 0.1 11.22 % 82 10.72 16.49 1.30 12.95 11A 11 0.19 0.60 0.79 10.5 1.91 I 0.1 I 0.50 9 I 26 I 0.012 12 13.56 16.49 1.50 12.73 ' 11 10 0.07 0.60 0.82 10.6 I 1.90 I 0.0 122.70 6 I 10 I 0.012 12 3.41 3.46 1.55 8.42 0.012 � 12 � 14.91 � 23.46 � 1.55 � 18.92 � SUMMATION OF AREA FROM 14 11 TIME FROM 14 10 9 0.00 1 0.60 1.28 10.9 1.87 0.1 3.06 t 35 0.012 12 7.95 ' 676 9 9A 0.00 0.60 1.27 11.0 1.86 0.1 2.08 t 24 0.012 I 12 I . 2.3 . 6.84 � 7.09 � 2.36 � 5.57 SA 5 111.00 0.15 1.64 20.0 1.26 0.1 7.73 % 55 0.012 12 1 5 3 0.03 0.60 1.64 20.1 1.26 0.3 2.09 8 137 0.012 I 12 6.64.6 1 . 2.06 1 .74 � 7.10 2.06 5.58 ' 4 3 3.40 0.60 2.03 8.2 2.21 0.0 21.11 % 19 ( 0.012 12 19.06 22.62 9.48 17.76 SUMMATION OF AREA FROM 5 4 TIME FROM 5 2 0.10 0.60 1 3.72 20.4 1.25 0.1 2.38 6 61 0.012 12 8.42 7.59 1 4.65 5.96 0.10 0.60 3.76 20.5 1.24 0.2 1.56 4 85 0.012 12 6.19 6.19 4.66 4.82 8 7 115.35 0.15 2.30 12.0 1.76 0.4 11.00 % 360 0.012 12 14.54 16.33 1 4.04 j 12.82 1 1 0.31 0.60 2.48 1.12.4 1 1.74 0.1 1.67 8 55 0.012 12 7.16 6.35 9.31 4.99 SUMMATION OF AREA FROM 2 7 TIME FROM 2 1 1A 0.16 0.60 6.32 20.7 1.23 0.1 1.50 1 50 0.012 18 8.12 7.90 7.77 13.96 ' 6A 6 0.16 0.60 0.09 10.0 1.96 0.1 1.00 4 18 0.012 12 2.54 6 6B 0.01 0.60 0.09 10.1 1.95 0.1 5.47 1 15 0.012 12 4.61 I 11..5 9 1 0.17 .04 1 � 0.17 � .04 � TRIAD DESIGNED BY _SGM DATE_6/16/99 STORM SEWER DESIGN ASSOCIATES CHECKED BY MDM DATE 6/16/94_1 PROJESUMMIT PARK 93-064 APPROVED BY CAL - - DATE -6/16/94_1 PROJECT NAME JOB NO. 11415 NE 128th St. Kirkland, WA 98033 (206) 821-8448 SHEET 1 OF 1 r li IN IS all NO ,�/ M �r ' 6/15f94 TRIAD Associates page 1 SUMMIT PARK RETENTION /DETENTION CALCULATIONS ' &-BIOFILTRATION-SWALE-CALCS__________________________________________ BASIN SUMMARY BASIN ID: AD3 NAME: 1/3 2YR SBUH METHODOLOGY ' TOTAL AREA. . . . . . . : 2.00 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 0.67 inches AREA. . : ' 0.80 Acres TIME INTERVAL . . . . : 10.00 min CN. . . . : 86.00 TIME OF CONC . . . . . : 7.33 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA. . : 1 .20 Acres CN. . . . 98.00 TcReach - Sheet L : 300.00 ns:0.0500 p2yr : 2.00 s:0.0900 TcReach - Channel L: 35.00 kc:42.00 s:0.0800 TcReach - Channel L: 140.00 kc: 42.00 s :0. 1250 TcReach - Channel L: 60.00 kc : 42 .00 s:0.0050 PEAK RATE: 0. 15 cfs VOL: 0.05 Ac-ft TIME: 480 min ' BASIN ID: 9D3 NAME: 2YR DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 70 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 0.67 inches AREA. . : 0.64 Acres TIME INTERVAL. . . . : 10.00 min CN. . . . : 86 .00 TIME OF CONC. . . . . : 4.87 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1 .06 Acres CN. . 98.00 TcReach - Sheet L: 190 .00 ns :0.0500 p2yr : 2.00 s:0. 1050 TcReach - Channel L: 100.00 kc : 42.00 s:0.0600 ' TcReach - Channel L : 50.00 kc :42.00 s:0. 1400 TcReach - Channel L: 120.00 kc: 42 .00 s :o.0850 TcReach - Channel L: 65.00 kc : 42 .00 s :0 .2000 PEAK RATE: 0. 14 cfs VOL: 0 .05 Ac-fit TIME: 470 min 1 r r r r r r 6115194 TRIAD Associates page 2 SUMMIT PARK RETENTION /DETENTION CALCULATIONS & 210FILTRATION SWALE CALCS. REACH SUMMARY DITCH REACH ID No. B1 Ditch Length: 200. 00 ft Ditch Width: 4 .00 ft Side Slopel : 3 .00 Ditch Slope: 0.0200 fit/fit Side Slope2 : 3.00 Contrib Bas: ' Mannings n : 0 .3500 Dn Invert- : 0 .00 ft Dn W .S . Elev : 0.0000 Num Steps 10 Trib Area : 3 . 70 Ac. Design Flow 0 .24 cfs Depth 0. 24 ft Vel 0. 21 fps Upstream W.S . Elev : 0. 00 ft . rDITCH REACH ID No. 82 Ditch Length: 130 . 00 ft Ditch Width : 7 .00 ft ' Side Slopel . 3 .00 Ditch Slope: 0 .0050 ft/ ft Side Slope2 : 3 .00 Contrib Bas : Mannings n :0.0270 Dn Invert 0 . 00 ft Dn W .S . Elev :0.0000 Num Steps 10 Trib Area : 3. 70 Ac . Design Flow : 0 . 27 cfs Depth 0 . 06 ft Vel 0 .61 fps Upstream W.S . Elev : 0 .00 ft . ' DITCH REACH ID No . 83 Ditch Length: 130.00 ft Ditch Width: 7 .00 ft Side Slopel . 3 .G0 Ditch Slope : 0 . 0050 ft/ft Side Slope2 : 3 .00 Contrib Bas: Mannings n : 0 .0270 Dn Invert : 0 .00 ft . Dn W .S . Elev :0.0000 Num Steps 10 Trib Area : 3.70 Ac. Design Flow 3 . 03 cfs Depth 0.26 ft Vel 1 .49 fps Upstream W .S. Elev: 0.00 ft . �- - �jl!/LJ,►tilJ ,� � =a�«Q 000 ,wow =UU wQ¢ tj r eb ® 1 D, 2� G�5 _ _ h -o '� — h = o,� 3�1 6(01iI i 8O �� 1 1 1 TIR SECTION VI. SPECIAL REPORTS AND STUDIES 1 A Geotechnical Report was prepared for the site on April 13, 1994 by Terra Associates and is included in the appendix section. Based upon this report, no special 1 circumstances where cited.. No other Special Reports and Studies are required. 1 1 1 TIR SECTION VII. BASIN AND COMMUNITY PLAN AREAS This site is not within a Basin or Community Plan Area. 1 1 1 TIR SECTION VIII. OTHER PERMITS No other permits have been required for this project. 1 1 1 i 1 10 TIR SECTION IX. ' EROSION/SEDIMENTATION CONTROL DESIGN ' The erosion control measures for the site were designed using current King County Standards as outlined in Chapter 5 of the 1990 SWM Surface Water Drainage Manual. This project proposes to use the permanent detention pond as the Temporary Sediment Pond since the site will be graded to direct flows towards the pond and more than enough volume is provided. Based upon the attached calculations, the required pond storage volume is 730.80 cu. ft., the volume provided is 5475.0 cu.ft., resulting in excess volume of 4744.2 cu. ft. The other erosion control measures proposed are interceptor swales, straw bale check dams in steeper areas, catch basin sumps in key locations, catch basin silt fence ' protection, and silt fencing at lower locations. These measures will combine to limit sediment runoff from the site during construction. 1 1 �1 I Axe �iV�cicl9 L ��,Ol��it�T �/CCU %A-Sc0 Z --. G� 4-aF'7 IGiE�/`I/l�?t1� G✓7-o�e-L��� I�GU��; �Er� o'o s ,dOleG/-ter 2/9 c F 5 �� =O • /�OU�6 F�SrrG 2C2./9�/p,o o o 9 L = 2,7,3 5 y 5 UmL�RIA/, eW= 2 ' 1 1 1 IIA i i i i i i i � i � i i i i i i i i y i � z Slope I.S vnlues for following slope lengths 1,ft(m) IS vohocs for following slope lengths 1,ft(m) (� - _-.-- ,p Slope gradient 16 20 30 .10 5(1 GO 70 80 '90 100 150 2OO 250 .100 350 400 450 500 600 700 800 900 1000 � (� ratio s, '., (3.0) (G.1) (9.1) (12.2) (15.2) (18.3) (21.3) (24.4) (27.4) (30.5) (.16) (GI) (76) (91) (107) (122) (137) (152) (183) (213) (2,14) (274) (305) _ 0.5 0.06 0.07 0.07 0.08 0.08 0.09 0.()() 0.09 0.09 0.10 0.10 0.11 0.11 0.12 0.12 0.13 0.13 0.11 0.14 0.14 0.14 0.15 0.15 C C IIN1:1 1 0.08 0.09 O.IO 0.10 0.11 0.11 0.12 0.12 0.12 0.12 0.1.1 0.1.1 0.15 0.IG 0.IC, O.ir, 0.17 0.17 0.18 0.18 0.I9 0.19 0.20 � z 2 0.10 0.12 0.1 1 0.15 0.16 0.17 0.18 0.19 ().19 0.20 0.23 0.25 0.2(i 0.28 0.29 0.30 0.32 0.33 0.34 0.36 0.37 0.39 0.40 3 0.14 0.18 0,20 0.22 0.23 0.25 0.2r, 0.27 0.28 0,29 0.32 0.35 0.38 0.40 0.42 0.43 0.45 0.46 0.49 0.51 0.54 0.65 0.57 4 0.16 0.21 0.25 0.28 0.30 0.33 0.35 0.37 0.38 0.40 0.47 0.53 0.58 0.62 0.66 0.70 0.73 0.76 0.82 0.87 0.92 0.96 1.00 f/ • i! 20:1 5 0.17 0.24 0.29 0.34 0.38 0.41 0.45 0.48 0.51 0.53 0.66 0.16 0.85 0.93 1.00 1.07 1.13 1.20 1.31 1.42 1.S1 1.60 1.69 C G 0.21 0.30 0.37 0.4.1 0.48 0.52 0.56 0.60 O.G4 0.67 0.82 0.95 1.06 1.16 1.26 1.34 1.4.1 1.50 1.65 1.78 1.90 2.02 2.13 oD 7 0.26 0.37 0.45 0.52 0.58 0.6-1 0.69 0.74 0.78 0.82 1.01 1.17 1.30 1.43 1.54 1.65 1.75 1.84 2.02 2.18 2,33 2.47 2.61 � 12'1:1 8 0.31 0.44 0.54 0.6.1 0.70 0.77 0.83 0.89 0.9.1 0.99 1.21 1.40 1.57 1.72 1.85 1.98 2.10 2.22 2.43 2.62 2.80 2.97 3.13 9 0.37 0.52 0.64 0.74 0.8.1 0.91 0.98 1.05 1.11 1.17 1.44 1.66 1.85 2.03 2.19 2.35 2.49 2.62 2.87 3.10 3.32 3.52 3.71 10:1 IO 0.43 0.61 0.75 0.87 0.97 1.06 1.15 1.22 1.30 1.37 . 1.68 1.94 2.16 2.37 2.56 2.74 2.90 3.06 3.35 3.62 3.87 4.11 4.33 z 11 0.50 0.71 0.86 1.00 1.12 1.22 1.32 1.41 1.50 1.58 1.93 2.23 2.50 2.74 2.95 3.16 3.35 3.53 3,87 4.18 4.47 4,74 4.99 8:1 0.61 0.86 1.05 1.22 1.36 1.49 1.61 1.72 1,82. 1.92 2.35 2.72 3.04 3.33 3.59 3.84 4.08 4.30 .08 5.43 5.76 6.08 y 0.81 1.14 1.40 1.62 1.81 1.98 2.14 2.29 2.43 2.56 3.13 .1.62 4.05 4.43 4.79 6.f2--543 "2 6.27 6.77 7.24 7.68 8.09 O 6:1 16.7 0.96 1.36 1.67 1.92 2.15 2.36 2.54 2.72 2.88 3.04_ 3.72 4.30 4.81 5.27 5.69 6.08 6.45 6.80 7.45 8.04 8.60 9.12 9.62 z 5:1 20 1.29 1.82 2.23 2.58 2.88 3.16 3.41 3.65 3.87 4.08 5.00 5.77 6.45 7.06 7.63 8.16 8.65 9.12 9.99 10.79 11.54 12.24 12.90 to 4h:1 22 1.51 2.13 2.61 3.02 3.37 3.69 3.99 4.27 4.53 4.77 5.84 6.75 7.54 8.26 8.92 9.54 10.12 10.67 11.68 12.62 13.49 14.31 15.08 (" 4:1 25 1.86 2.63 3.23 3.73 4.16 4.56 4.93 5.27 5.59 5.89 7.21 8.33 9.31 10.20 11.02 11.78 12.49 13.17 14.43 15.58 16.66 17.67 18.63 r� 30 2.51 3.56 4.36 5.03 5.62 6.16 6.65 7.11 7.54 7.95 9.74 11.25 12.57 13.77 14.88 15.91 16.87 17.78 19.48 21.04 22.49 23.86 25.15 3.1 33.3 2.98 4.22 5.17 5.96 6.67 7.30 7.89 8.43 8.95 9.43 11.55 13.34 14.91 16.33 17.64 18.86 20.00 21.09 23.10 24.95 26.67 28.29 29.82 35 3.23 4.57 5.GO G.46 7.23 7.92 8.55 9.14 9.70 10.22 12.52 1.1.46 16.16 17.70 19.12 20.44 21.68 22.86 25.04 27.04 28.91 30.67 32.32 C� 215:1 40 4.00 5.66 6.93 8.00 8.95 9.80 10.59 11.32 12.00 12.65 15.50 17.89 20.01 21.91 23.67 25.30 2G.84 28.29 30.99 33.48 35.79 37.96 40.01 45 4.81 6.80 8.33 9.61 10.75 11.77 12.72 13.60 14.42 15.20 18.62 21.50 24.03 26.33 28.44 30.40 32.24 33.99 37.23 40.22 42.99 45.60 48.07 C 2:1 50 k.64 7.97 9.76 11.27 12.60 13.81 14.91 15.94 16.91 17.82 21.83 25.21 28.18 30.87 33.34 35.65 37.81 39.85 43.66 47.16 50.41 53.47 56.36 55 6.48 9.16 11.22 12.96 14.48 15.87 17.14 18.32 19.43 20.48 25.09 28.97 32.39 35.48 38.32 40.97 43.45 45.80 50.18 54.20 57.94 61.45 64.78 IY.:1 57 6.82 9.64 11.80 13.63 15.24 16.69 18.03 19.28 20.45 21.55 26.40 30.48 34.08 37.33 40.32 4.1.10 45.72 48.19 52.79 57.02 60.96 64.66 68.15 GO 7.32 10.35 12.68 14.64 16.37 17.93 19.37 20.71 21.96 23.15 28.35 32.74 3G.GO 40.10 43.31 46.30 49.11 51.77 5G.71 61.25 65.48 69.45 73.21 I K:1 66.7 8.44 11.93 14.61 16.88 18.87 20.67 22.32 23.87 25.31 26.68 32.68 37.74 42.19 46.22 49.92 53.37 56.60 59.66 65.36 70.60 75.47 80.05 84.38 70 8.98 12.70 15.55 17.96 20.08 21.99 23.75 25.39 26.93 28.39 34.77 40.15 44.89 49.17,53.11 56.78 60.23 63.48 69.64 75.12 80.30 85.17 89.78 75 9.78 1.1.83 1G.94 19.56 21.87 23.95 25.87 27.66 29.34 30.92 37.87 43.73 48.89 53.56 57.85 G1.85 65.60 69.15 75.75 81.82 87.46 92.77 97.79 1K:1 SO 10.55 14.93 18.28 21.11 23.00 25.85 27.93 29.85 3LOG 33.38 40.88 47.20 52.77 57.81 62.44 66.75 70.80 74.63 81.76 88.31 94.41 100.13 105.55 CA 85 11.30 15.98 19.58 22.61 25.27 27.69 29.90 31.97 33.01 38,74. 43.78 50.55 56.51 61.91 66.87 71.48 75.82 79.92 87.55 04.67 101.09 107.23 113.03 ~ 90 12.02 17.00 20.82 24.04 26.88 29.44 31.80 34.60 36.06 38.01' 46.55 63.76 60.10 65.84 71.11 76.02 80.63 84.99 93.11 100.57 107.51 114.03 120.20 ni 95 12.71 17.97 22.01 25.41 28.41 31.12 3.1.62 35.94 38.12 40.18 49.21 56.82 63.53 69.59 75.17 80.36 85.2..1 89.84 98.42 106.30 113.64 120.54 127.06 z 1:1 1M 13.36 18.89 2.1.14 26.72 29.87 32.72 35.34 37.78 40.08 42.24 51.74 59.74 66.79 73.17 79.03 84.49 89.61 94.46 10.1.48 111.77 119.48 126.73 133.59 *Calculated from 65.41 X s= + 4.56 X s +0.0651 ff 1 ll IS- topographic factor 1sr + 10,000 \72.6/- I-slope length,ft(m X 0.3048) z s -slope steepness, m - exponent dependent upon slope steepness (0.2 for slopes< 1%.0.3 for slopes I to 3%, 0.4 for slopes 3.5 to 4.5%,and 0.6 for slopes>5%) o � _ ----------- - - - -- - -- - - - - - - - - - - -- - 6TALBOT RDADmt SOUTH_ IT 71 I ; ,, I i - ra iaar r _ _ I TOE 1787 e _f I I I _ _. � I - o --- � 0 S S Z: 7. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL ' o To complete the design of the temr?orarV sediment trap: a. The "Pond Geometry Equations" section in the "Reference" portion at the back of the Manual may also be useful in designing the sediment trap. b. A 3:1 aspect ratio between the trap length and width of the trap Is desirable. Length is ' defined as the average distance from the inlet to the outlet of the trap. This ratio Is included in the computations for Figure 5.4.4C for the surface area at the interface between the settling zone and sediment storage volume. ' C. Determine the bottom and top surface area of the sediment storage volume to be provided (see Figure 5.4.4C) while not exceeding 1.5' in depth and 3:1 side slope from the bottom of the trap. Note the trap bottom should be level. ' d. Determine the total trap dimensions by adding an additional 2' of depth above the surface of the sediment storage volume, while not exceeding 3:1 side slopes, for the required settling volume. (see Figure 5.4.4C) ' TABLE 5.4.4A HYDROLOGIC SOIL GROUP OF THE SOILS IN KING COUNTY SOIL SOIL EROD- EROD- HYDROLOGIC IBIUTY HYDROLOGIC IBILITY SOIL GROUP GROUP* FACTOR,-K' SOIL GROUP GROUP* FACTOR,"K' ' Alderw C 0.1 Orcas Peat D 0.00 Arents, Alderwood C Oridia D 0.49 Arents, Everett B 0.17 Ovall C 0.17 Beausite C 0.15 Pilchuck C 0.10 '�- Bellingham D 0.32 Puget D 0.28 Briscot D 0.32 Puyallup B 0.28 Buckley D 0.32 Ragnar B 0.32 Coastal Beaches Variable 0.05 Renton D 0.43 ' Earlmont Silt Loam D 0.37 Riverwash Variable - Edgewick C 0.32 Sala] C 0.37 Everett A 0.17 Sammamish D 0.37 Indianola A 0.15 Seattle D D.00 ' Khsap C 0.32 Shacar D 0.00 Klaus C 0.17 SI Sat C 0.37 Moved Alluvial Land Variable 0.10 Snohomish D 0.32 Nelton A 0.10 Sultan C 0.37 Newberg B 0.32 Tukwila D 0.00 ' Nooksack C 0.37 Urban Variable - Norm. Sandy Loam D 0.24 Woodinville D 0.37 ' HYDROLOGIC SOIL GROUP CLASSIFICATIONS A_ (Low runoff potential). Soils having high Infiltration rates, even when thoroughly wetted, and consisting ' chiefly of deep,well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. B. (Moderately low runoff potential). Solis having moderate Infiltration rates when thoroughly wetted, and consisting chiefly of moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission. C. (Moderately high runoff potential). Soils having slow infiltration rates when thoroughly wetted, and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately ' fine to fine textures. These soils have a slow rate of water transmission. D. (High runoff potential). Soils having very slow Infiltration rates when thoroughly wetted and consisting chiefly of,day soils with a high swelling potential,sots with a permanent high water table, soils with a hardpan or clay layer at or near the surface,and shallow soils over nearly Impervious material. These sots have a very slow rate of water transmission. From SCS, TR-55, Second Edition,June 19W. Exhibit A-1. Revisions made from SCS, Soils Interpretation Record, Form #5, September 1988. 5.4.4.I-3 I/g0 TIR SECTION X. BOND QUANTITIES WORKSHEET, ' RETENTION/DETENTION FACILITY SUMMARY SHEET AND DECLARATION OF COVENANT 12 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL RETENTION/DETENTIONI S SUMMARY SHEET ' Development 1 7— Date -V Location ENGINEER DEVELOPER Name Name ////rPoifJ/j1�/U%� Firm Address 128 Tom — Address PD.9ox /5ZX Phone �621—5446 Phone Developed Site 2Lacres Number of Lots 2S Number of Detention Facilities On Site • Detention provided in regional facility Regional Facility location • No detention required 0 Acceptable receiving waters Downstream Drainage Basins ' Immediate Major Basin Basin A Basin B Basin C Basin D TOTAL INDIVIDUAL BASIN Drainage Basin(s) A B C D Onsite Area ' Off site Area Type of Storage Facility o�cn� ow5� Live Storage Volume eg1SC- F Predeveloped Runoff Rate 2 year 0 10 year ' Postdeveloped Runoff Rate 100 year 2 year 10 year 7 ' Developed Q 100 year 3.I Type of Restriction Size of Orifice/Restriction �_- Orifice/Restriction No.1 �.28 No.2 No.3 . �7 ' No.4 No.5 King County ' Building and Land Development Division BOND QUANTITIES WORKSHEET SUBDIVISION PRODUCTS SECTION Page 1 of 2 ' Date:� File No. nNE= 4 �99�{ -7 Project: / ( Site Address: 7000 9' �//D rZe07_ �D ' INSTRUCTIONS TO DESIGN ENGINEER: Using this form and the unit prices provided, fill in those items which pertain to road, drainage and erosion control for the above project. You must submit this form with the plan submittal for approval. Compute the subtotals and complete the signature block. ' *** EXISTING RIGHT-OF-WAY *** *** FUTURE RIGHT-OF-WAY *** IMPROVEMENTS/SITE STABILIZATION AND ON-SITE IMPROVEMENTS ' Unit ------------------------------- --------------------------- ROAD & ROAD DRAINAGE: Price Units Quantity Price Quantity Price Clearing & Grubbing LS 17 S (60U (_S = 1200 ' Excavation & Embankment $5.00 CY ;;0 0 15 0 C) Yffoo $ 49,00o A.C. Pavement & Rock Base 10.00 Sr ?e;y -Zj 0 0 0 0 pC;C) . Cement Conc. Curb & Gutter. 6.00 LF 7d 172 2 0 9Z Q Z D Extruded Asphalt Curb . . . 4.00 LF ' Concrete Sidewalk . . . . . 9.00 LF 3�0 '2'9j is,Q 0 12" Culvert . . . . . . . . 15.00 LF �? 15 j ram"0 18" Culvert . . . . . . . . 20.00 LF (oQ fa00 _ �-- 241' Culvert . . . . . . . . 26.00 LF — 36" Culvert . . . . . . . . 40.00 LF — ' INLET & Grate . . . . . . . 500.00 ea. CB TYPE I & Grate . . . . . 750.00 ea. ?j co 0 /7 C8 TYPE 11 48" & Grate. . . 1400.00 ea. ' CB TYPE 11 54" & Grate. . . 1600.00 ea. Riprap (quarry spans). . . 17.00 CY 00 _ 3(1-46 RETAINING WALLS & STRUCTURES: LS Rockery Facia Walls . . . . 5.00 SF OCR 221 SGb TRAFFIC CHANNELIZATION: Signalization . . . . . . . LS Channelization. . . . . . . LS SITE STABLIZATION/EROSION CONTROL: 3 Rock Construction Entrance. 300.00 ea. 0•co ' Seeding/Mulch . . . . . . . 3000.00 ACRE //1 70 0,00 Silt. Fence. . . . . . . . . 4.00 LF Netting/Jute Mesh . . . . . 5.00 SY _ Sediment Pond Standpipe 200.00 ea. / 100,00 Temporary Pipe ( " dia) le,7,00 ?00, 25 SUBTOTAL THIS PAGE SUBTOTAL: S to SUBTOTAL E / 7 �J BOND QUANTITIES WORRSHEET King County Building and Land Development Division Page 2 of 2 SLIOIVISION PRODUCTS SECTION ' RETENTION/DETENTION FACILITIES AND CONVEYANCE SYSTEMS --------------------------- Unit Price Units Quantity Price RETENTION/DETENTION & CONVEYANCE: Pond Excavation & Spillway. 5.00 CY1�0 O 7 Tank - 48" Culvert. . . . . 50.00 LF — ' Tank - 60" Culvert. . . . . 65.00 LF = CB TYPE I & Lid . . . . 750.00 ea. CS TYPE li 48" & Lid. . . . 1400.00 ea. CS TYPE 11 54" & Lid. . . . 1600.00 ea. Restrictor/Separator 12". 450.00 ea. 12" CULvert(Outfall & Convey) 15.00 LF 697 Ej ' 18" Culvert . . . . . . . . 20.00 LF Rip Rap Outfall Protection. 17.00 CY ' Access Road/Bollards. . . . 500.00 LS _Fencing (around pond) 9.00 LF Infiltration Trench . . . . 15.00 LF Flow Spreader . . . . . . . 15.00 LF Trash Racks 200.00 LF ' SUBTOTAL S Z -00 t Signatu . /� Registration Number: Firm Telephone Number: 1 The following information will be completed by the Engineering Review Unit. EXISTING ROADWAY IMPROVEMENTS: S 3 (5,I & SITE RESTORATION G� FUTURE ON-SITE IMPROVEMENTS: S / RETENTION/DETENTION 8 CONVEYANCE S S�Z� ' SUBTOTAL: S�,�/ f� 20 % CONTINGENCY: S `t 5 7pp,5; ' TOTAL BOND AMOUNT: S Z? 7 r ' BONDOUAN.WS2:880127 1/90 ' TIR SECTION XI. MAINTENANCE AND OPERATIONS MANUAL ' Description of the R/D Facility: The proposed R/D facility is comprised of an open pond with 3:1 side slopes. Storm runoff flows enter the pond at two locations and are detained to the pre-developed rates thus allowing for ponding during a major storm event for a relatively short period of time. The flows will be controlled by a manhole with an orifice stack having orifices sized for each of the required ' storm events. It will also serve as a settlement area for sediments generated in the new development. Recommended Maintenance Tasks and Frequency at which maintenance should occur: Task When to be performed Trash and debris removal Every 6 months , or as needed Grass/weed removal When growth exceeds 18" of height Inspect/Clean Control Structure Inspect every 6 months, clean as needed Sediment Removal When accumulation reaches 6" deep Pond side slopes When eroded damage is over 2" 13 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 1 - PONDS ' Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed ' General Trash & Debris Any trash and debris which exceed 1 Trash and debris cleared from site. cubic foot per 1000 square feet (this is about equal to the amount of trash it ' would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Poisonous Any poisonous vegetation which may No danger of poisonous vegetation where ' Vegetation constitute a hazard to County personnel County personnel or the public might or the public. Examples of poisonous normally be. (Coordination with vegetation include: tansy ragwort, poison Seattle/I(ing County Health Department) oak,stinging nettles,devils dub. Pollution Oil,gasoline,or other contaminants of No contaminants present other than a one gallon or more or any amount found surface film. (Coordination with that could: 1) cause damage to plant, Seattle/I(ing County Health Department) animal,or marine fife; 2)constitute a fire hazard; or 3) be flushed downstream during rain storms. Unmowed Grass/ H facility is located in private residential When mowing is needed, grass/ground Ground Cover area,mowing is needed when grass cover should be mowed to 2 Inches in i exceeds 18 inches in height. in other height. areas,the general policy Is to make the pond site match adjacent ground cover and terrain as long as there is no ' interference with the function of the facility. Rodent Holes Any evidence of rodent holes if facility is Rodents destroyed and dam or berm acting as a dam or berm,or any evidence repaired. (Coordination with Seattle/ of water piping through dam or berm via Kng County Health Department) rodent holes. Insects When insects such as wasps and hornets Insects destroyed or removed from site. interfere with maintenance activities. ' Tree Growth Tree growth does not allow maintenance Trees do not hinder maintenance access or interferes with maintenance activities. Selectively cultivate trees such activity (.e.,slope mowing,silt removal, as alders for firewood. vactoring or equipment movements). if trees are not interfering with access, leave trees alone. Side Slopes of Erosion Eroded damage over 2 inches deep Slopes should be stabilized by using Pond where cause of damage is still present or appropriate erosion control measure(s): where there is potential for continued e.g., rock reinforcement, planting of erosion. grass, compaction. Storage Area Sediment Accumulated sediment that exceeds 10% Sediment cleaned out to designed pond of the designed pond depth. shape and depth; pond reseeded if necessary to control erosion. Pond Dikes Settlements Any part of dike which has settled 4 Dike should be built back to the design ' inches lower than the design elevation. elevation. Emergency Rock Missing Only one layer of rook exists above native Replace rocks to design standards. Overflow/Spillway soil in area five square feet or larger, or any exposure of native soil. ' A-1 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL ' I NO. 2 - INFILTRATION O Maintenance Conditions When Maintenance Results Expected Component Defect is Need*d When Maintenance is Performed ' General z Trash &Debris See 'Ponds' Standard No. 1 See'Ponds Standard No. 1 Poisonous See 'Ponds' Standard No. 1 See'Ponds Standard No. 1 Vegetation ' Pollution See 'Ponds' Standard No. 1 See'Ponds Standard No. 1 Unmowed Grass/ See'Ponds'Standard No. 1 See 'Ponds Standard No. 1 ' Ground Cover Rodent Holes See'Ponds'Standard No. 1 See'Ponds Standard No. 1 Insects See'Ponds'Standard No. 1 See'Ponds Standard No. 1 ' Storage Area Sediment A percolation test pit or test of facility Sediment is removed and/or facility Is indicates facility is only working at 90%of cleaned so that Infiltration system works its designed capabilities. according to design. ' Sheet Cover Sheet cover is visible and has more than Sheet cover repaired or replaced. (If Applicable) three 1/44nch holes In It. Sump Filled With Any sediment and debris filling vault to Clean out sump to design depth. ' Sediment and 10%of depth from sump bottom to Debris (If bottom of outlet pipe or obstructing flow Applicable) into the connector pipe. Filter Bags Filled with Sediment and debris fill bag more than Replace filter bag or redesign system. Sediment and 1/2 full. Debris �- Rock Filters Sediment and By visual inspection little or no water Replace gravel in rook filter. Debris flows through filter during heavy rain storms. A-2 I/90 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 3 - CLOSED DETENTION SYSTEMS (PIPES/TANKS) Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Perfornted Storage Area Plugged Air Vents One-half of the cross section of a vent is Vents free of debris and sediment. blocked at any point with debris and sediment. ' Debris and Accumulated sediment depth exceeds All sediment and debris removed from Sediment 10%of the diameter of the storage area storage area. for 1/2 length of storage vault or any point depth exceeds 15%of diameter. ' Example: 724nch storage tank would require cleaning when sediment reaches depth of 7 inches for more than 1/2 length of tank. Joints Between Any crack allowing material to be All Joints between tank/pipe sections are Tank/Pipe Section transported into facility. sealed. Tank/Pipe Bent Any part of tank/pipe is bent out of shape Tank/pipe repaired or replaced to design. ' Out of Shape more than 10%of its design shape. Manhole Cover not in Place Cover is missing or only partially in place. Manhole is dosed. Any open manhole requires maintenance. Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than 1/2 inch of thread (may not apply to self-locking lids). - Cover Difficult to One maintenance person cannot remove Cover can be removed and reinstalled by Remove lid after applying 80 pounds of lift. Intent one maintenance person. is to keep cover from sealing off access to maintenance. Ladder Rungs King County Safety Office and/or Ladder meets design standards and Unsafe maintenance person Judges that ladder is allows maintenance persons safe access. unsafe due to missing rungs, ' misalignment, rust,or cracks. Catch Basins See'Catch Basins'Standard No. 5 See'Catch Basins' Standard No.5 A-3 I/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL ' NO. 4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed ' General i Trash and Debris Distance between debris build-up and All trash and debris removed. (includes bottom of orifice plate is less than 1-1/2 Sediment) feet. 1 Structural Damage Structure is not securely attached to Structure securely attached to wall and manhole wall and outlet pipe structure outlet pipe. should support at least 1,000 pounds of up or down pressure. ' Structure is not in upright position (allow Structure in correct position. up to 10%from plumb). Connections to outlet pipe are not Connections to outlet pipe are watertight; ' watertight and show signs of rust structure repaired or replaced and works as designed. Any holes—other than designed holes— Structure has no holes other than in the structure. designed holes. ' Cleanout Gate Damaged or Cleanout gate is not watertight or is Gate is watertight and works as designed. Missing missing. ' Gate cannot be moved up and down by Gate moves up and down easily and is one maintenance person. watertight. Chain leading to gate Is missing or Chain is in place and works as designed. damaged. ' Gate Is rusted over 50%of its surface Gate Is repaired or replaced to meet area. design standards. Orifice Plate Damaged or Control device is not working property Plate is in place and works as designed. ' Missing due to missing,out of place,or bent orifice plate. Obstructions Any trash,debris,sediment,or vegetation Plate Is free of all obstructions and works blocking the plate, as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having Pipe is free of all obstructions and works the potential of blocking)the overflow as designed. pipe. ' Manhole See'Closed Detention Systems'Standard See'Closed Detention Systems' Standard No.3. No.3. Catch Basin See'Catch Basins" Standard No.5. See 'Catch Basins'Standard No.5. ' A-4 1/90 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed ' .General Trash &Debris Trash or debris of more than 1/2 cubic No trash or debris located immediately in (Includes foot which is located immediately in front front of catch basin opening. Sediment) of the catch basin opening or is blocking 1 capacity of basin by more than 10%. Trash or debris On the basin)that No trash or debris in the catch basin. exceeds 1/3 the depth from the bottom of basin to invert of the lowest pipe into ' or out of the basin. Trash or debris in any inlet or outlet pipe Inlet and outlet pipes free of trash or blocking more than 1/3 of its height. debris. Dead animals or vegetation that could No dead animals or vegetation present generate odors that would cause within the catch basin. complaints or dangerous gases (e.g., methane). ' Deposits of garbage exceeding 1 cubic No condition present which would attract foot in volume. or support the breeding of Insects or rodents. ' Structural Damage Corner of frame extends more than 3/4 Frame is even with curb. to Frame and/or inch past curb face into the street (f Top Slab applicable). Top slab has holes larger than 2 square Top slab is free of holes and cracks. inches or cracks wider than 1/4 inch (intent is to make sure all material is running into the basin). ' Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than 3/4 inch of the frame from the top slab. Cracks in Basin Cracks wider than 1/2 Inch and longer Basin replaced or repaired to design ' Walls/Bottom than 3 feet,any evidence of soil particles standards. entering catch basin through cracks,or maintenance person judges that structure is unsound. ' Cracks wider than 1/2 inch and longer No cracks more than 1/4 inch wide at the than 1 foot at the joint of any Inlet/outlet joint of inlet/outlet pipe. pipe or any evidence of soil particles entering catch basin through cracks. Settlement/ Basin has settled more than 1 inch or has Basin replaced or repaired to design Misalignment rotated more than 2 inches out of standards. alignment. ' Fire Hazard Presence of chemicals such as natural No flammable chemicals present. gas,oil,and gasoline. Vegetation Vegetation growing across and blocking No vegetation blocking opening to basin. more than 10%of the basin opening. Vegetation growing in inlet/outlet pipe No vegetation or root growth present. joints that is more than six inches tall and less than six inches apart. ' Pollution Nonflammable chemicals of more than No pollution present other than surface 1/2 cubic foot per three feet of basin film. length. A-5 IM KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS (Continued) Maintenance Condition* When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed 'Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Catch basin cover is closed. Any open catch basin requires maintenance. ' Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than 1/2 inch of thread. ' Cover Difficult to One maintenance person cannot remove Cover can be removed by one Remove lid after applying 80 lbs.of lift; intent is maintenance person. keep cover from sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs, Ladder meets design standards and Unsafe misalignment, rust,cracks, or sharp allows maintenance person safe access. edges. ' Metal Grates Grate with opening wider than 7/8 inch. Grate openings meet design standards. (if applicable) Trash and Debris Trash and debris that is blocking more Grate free of trash and debris. than 20%of grate surface. ' Damaged or Grate missing or broken member(s) of Grate is in place and meets design Missing the grate. standards. ' A-6 I/90 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 6 - DEBRIS BARRIERS (e.g. Trash Racks) ' Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed ' General Trash and Debris Trash or debris that is plugging more Barrier clear to receive capacity flow. than 20%of the openings in the barrier. Metal Damaged/ Missing Bars are bent out of shape more than 3 Bats in place with no bends more than Bars inches. 3/4 inch. Bars are missing or entire barrier Is Bars in place according to design. missing. ' Bars are loose and rust is causing 50% Repair or replace barrier to design deterioration to any part of barrier. standards. ' A-7 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL O. 7 - ENERGY DISSIPATORS Maintenance Conditions When Maintenance Resutts Expected Component Defect Is Needed When Maintenance is Performed temal: k Pad Missing or Moved Only one layer of rock exists above native Replace rooks to design standard. Rock soil in area five square feet or larger,or any exposure of native soil. aspersion Trench Pipe Plugged with Accumulated sediment that exceeds 20% Pipe cleaned/flushed so that it matches Sediment of the design depth. design. r Not Discharging Visual evidence of water discharging at Trench must be redesigned or rebuilt to Water Properly concentrated points along trench (normal standard. condition is a'sheet flow'of water along trench). Intent is to prevent erosion ' damage. Perforations Over 1/2 of perforations in pipe are Clean or replace perforated pipe. Plugged plugged with debris and sediment. ' Water Flows Out Maintenance person observes water Facility must be rebuilt or redesigned to Top of`Distributor' flowing out during any storm less than standards. Catch Basin the design storm w it is causing or appears likely to cause damage. r Receiving Area Water in receiving area is causing or has No danger of landslides. Over-Saturated potential of causing landslide problems. Internal: rManhole/Chamber Worn or Damaged Structure dissipating flow deteriorates to Replace structure to design standards. Posts, Baffles, 1/2 or original size or any concentrated Sides of Chamber worn spot exceeding one square foot which would make structure unsound. rOther Defects See 'Catch Basins'Standard No. 5 See 'Catch Basins' Standard No. 5 r r r r r r r rA-8 I/90 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 8 - FENCING 1 Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed 1 =General Missing or Broken Any defect in the fence that permits easy Parts in place to provide adequate Parts entry to a facility. security. Parts broken or missing. Broken or missing parts replaced. 1 Erosion Erosion more than 4 inches high and 12- No opening under the fence that exceeds 18 inches wide permitting an opening 4 inches in height. under a fence. 1 Wire Fences Damaged Parts Posts out of plumb more than 6 inches. Posts plumb to within 1-i/2 inches. Top rails bent more than 6 inches. Top rail free of bends greater than i inch. 1 Any part of fence (including posts,top Fence is aligned and meets design rails,and fabric) more than 1 foot out of standards. design alignment. Missing or loose tension wire. Tension wire in place and holding fabric. 1 Missing or loose barbed wire that is Barbed wire in place with less than 3/4- sagging more than 2-1/2 inches between Inch sag between posts. posts. 1 Extension arm missing, broken,or bent Extension arm in place with no bends out of shape more than 1-112 inches. larger than 3/4 inch. Deteriorated Paint Part or parts that have a rusting or scaling Structurally adequate posts or parts with 1 or Protective condition that has affected structural a uniform protective coating. Coating adequacy. Openings in Fabric Openings in fabric are such that an 8- No openings in fabric. inch-diameter ball could fit through. 1 1 1 1 i 1 1 ' A-9 1/90 1 _ KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 9 - GATES iMaintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed i General i Damaged or Missing pate or locking devices. Gates and locking devices in place. Missing Members Broken or missing hinges such that gate Hinges Intact and tubed. Gate is working cannot be easily opened and dosed by a freely. ' maintenance person. Gate Is out of plumb more than 6 Inches Gate is aligned and vertical. and more than 1 foot out of design i alignment. Missing stretcher bar, stretcher bands, Stretcher bar, bands,and ties in place. and ties. ' Openings in Fabric See'Fencing'Standard No.8 See'Fencing' Standard No.8 1 1 1 i 1 1 i 1 i iA_10 1/90 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 10 - CONVEYANCE SYSTEMS (Pipes & Ditches) Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed Pipes Sediment&Debris Accumulated sediment that exceeds 20% Pipe cleaned of all sediment and debris. of the diameter of the pipe. ' Vegetation Vegetation that reduces free movement of All vegetation removed so water flows water through pipes. freely through pipes. Damaged Protective coating is damaged; rust is Pipe repaired or replaced. causing more than 50%deterioration to ' any part of pipe. Any dent that decreases the cross section Pipe repaired or replaced. area of pipe by more than 20%. ' Open Ditches Trash &Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from ditches. per 1,000 square feet of ditch and slopes. Sediment Accumulated sediment that exceeds 20% Ditch cleaned/flushed of all sediment and of the design depth. debris so that it matches design. Vegetation Vegetation that reduces free movement of Water flows freely through ditches. water through ditches. Erosion Damage to See 'Ponds' Standard No. 1 See 'Ponds' Standard No. 1 Slopes Rock Uning Out of Maintenance person can see native soil Replace rocks to design standard. Place or Missing (If beneath the rock lining. Applicable) Catch Basins See 'Catch Basins' Standard No. 5 See 'Catch Basins' Standard No. 5 Debris Barriers See'Debris Barriers' Standard No. 6 See 'Debris Barriers' Standard No. 6 (e.g.,Trash Rack) ' A-11 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL ' NO. 11 - GROUNDS (Landscaping) - ' Maintenance Conditions When Maintenance Results Expected component Defect Is Needed When Maintenance Is Performed ' General Weeds Weeds growing in more than 20%of the Weeds present in less than 5%of the (Nonpoisonous) landscaped area (trees and shrubs only). landscaped area. Safety Hazard Any presence of poison Ivy or other No poisonous vegetation present in a poisonous vegetation. landscaped area. Trash or Utter Paper,can,bottles,totalling more than 1 Area dear of litter. cubic foot within a landscaped area (trees and shrubs only)of 1,000 square feet. Trees and Shrubs Damage Umbs or parts of trees or shrubs that are Trees and shrubs with less than 5%of the split or broken which affect more than total foliage with split or broken limbs. 25%of the total foliage of the tree or shrub. Trees or shrubs that have been blown Tree or shrub in place free of injury, down or knocked over. Trees or shrubs which are not adequately Tree or shrub in place and adequately supported or are leaning over,causing supported; remove any dead or diseased exposure of the roots. trees. t r A-12_ 1/90 ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 12 - ACCESS ROADS/EASEMENTS Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance is Performed ' General Trash and Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from site. per 1,000 square feet, i.e.,trash and debris would fill up one standard size ' garbage can. Blocked Roadway Debris which could damage vehicle tires Roadway free of debris which could (glass or metal). damage tires. Any obstructions which reduce clearance Roadway overhead clear to 14 feet high. above road surface to less than 14 feet. My obstructions restricting the access to Obstruction removed to allow at least a a 10-to 12-foot width for a distance of 12-foot access. more than 12 feet or any point restricting access to less than a 10-foot width. Road Surface Settlement, When any surface defect exceeds 6 Road surface uniformly smooth with no ' Potholes, Mush inches in depth and 6 square feet in area. evidence of settlement, potholes, mush Spots, Ruts In general, any surface defect which spots,or ruts. hinders or prevents maintenance access. Vegetation in Road Weeds growing in the road surface that Road surface free of weeds taller than 2 Surface are more than 6 inches tall and less than inches. 6 Inches apart within a 40G-square-foot area. Shoulders and Erosion Damage Erosion within 1 foot of the roadway more Shoulder free of erosion and matching Ditches than 8 inches wide and 6 inches deep. the surrounding road. Weeds and &ush Weeds and brush exceed 18 inches in Weeds and brush out to 2 inches In height or hinder maintenance access. height or cleared in such a way as to allow maintenance access. ' I A-13 /90 x 0 Z W a a Q ^ 7AVS ro ST AV S N Ar 84TH � AV N. BSTH N STH AV S 'N 1 IN .-• iv S ------_ S- 1 1 F </ 88TH AV TH AV 'AV s - SBIND Ya $ —--—-—---- -----—-- S—'� li >. R� lit , 92ND AV RS _ _ _ _ C 1y S PL 93RD ro DA R R RD , ti 94THAV S oN 9STH AVWY fl 96TM wr 96TH AV S %TH ., _ ,TALB �� s Z 96TH PL "' o� 98TH oR' 4 v N 98TH PL S�r'� W 4 f 98TH AV S s ';.'_� I TH�vf •± y Ts...,:' +O�•y3Ku. 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I � ( �.. � .,� _ ♦ \ .. ... , I t. , \ I r�T i H.Iillld.l I• � � - `1 I M M M M M M M M M M M M M M M M M M M Trib R Collect Existing Anticipated Item River Mile Point Category Prop. I'roj. Conditions and Problems Conditions and Problems Recommendations 30 0020 21 IIabitat Excess sediment from Further sedimentation from Several options: construct sediment RM .60 upstream has destroyed a upstream sediment sources. pond above Talbot Road. Reduce private trout farm. flow rates and volumes in Trib. Thousands of fish were 0021. Increase R/D upstream of killed during Jan. '86 Talbot Rd. Down-zone land to storm. reduce surface water impacts of future development. 31 0021 22, Geology Bank erosion, landsliding Problems will continue. - Control storm flows: R/D above RM .00 in ravine due to outfalls RM .40 in 0021; reroute or 0.50 at end of SE 196th St. control flows from vicinity of and from R/D pond at SE SE 200th (tightline flows west 200th plus natural on 200th). sensitivity (landslides). - Provide energy dissipation at R/D Heavy damage in Jan. '86 outfall (RM .40). storm. Sedimentation above - Restrict development on north side old road and in trout farm of 0021 (runoff to be tightlined below Talbot Rd. (0020), as or routed around canyon). well as erosion in the canyon. 32 0021 22 Hydrology 0302 The upper reaches of Development will continue - Construct a regional R/D faci- RM .40 Springbrook Creek lie and impervious area will lity in the natural drainage within the city of Renton continue to grow. Increased swale at the upper reaches of City Watershed. The creek nmoff will further erode this system. originates in highly ero- the unstable soils carrying - Construct a dam across the Swale sive and steeply sloping sediment and debris with an outlet control structure soils. Alterations of the downstream, where they will and an overflow spillway. natural drainage patterns reduce the efficiency of or - Tightline existing drainage into by development, roadway even destroy culverts, pipe- circa to further reduce erosion and construction, and poor lines, and streambeds. raise existing roadway to prevent practice in handling Flooding could result from flooding. runoff have increased ero- the inefficient facilities sion and sediment coupled with the greater transport to the lower runoff. gradient downstream reaches. P:13R.APC/mlm C-8 tin SIN oil 211 n Mee 'Sty • � � n� mug of ims soon IS LEW win sir a `1 �s 1 �1 �WS � ■.Ilhii(ii N � AM ISMAW 1 ■ N MEN INS .�. 's' jai �r Mfg 060 •,VMowe: ses�r_ MEOW- °I INN ♦a�fON � a "i ' �( �j) 4MOW mr.�K-..��� -ram • � -WIN gum r INS ^°'—° p! i� ►�,'"atb<. :�% 1'�'..��! �.+1��I 1 I.t�t �d, ���5�7aa� -� - ...- �o^/�+ye li• lu 6i6 " ^ *-t — d- h 'n NLr- .WIT � ill ■ J low," kid WE m L min PENNER I lot��l1� �� • pt Now � � �`:'. r--fin `� �W���„■,� ■If. lMR fly --� ,�.. �i�s ��=� ,� �,� �.7■®� •°�Iil�l,Ii , �' 7 r..��7�w,v ® (� ¢�i a' �L""=—� .�� -- 1 a IFNI HIM mqm Inn �. NOW �171. �� 1'►�;. ��� •w ,u • HIP W d� I ■s � � Ahe � � � �V4 ti � - MUM s I r I 1 • p i �� me NMI i `its x . E Al ' -- APE s,w�h �-, "'-� s. ® = ice• r is i• GEOTECHNICAL REPORT Summit Park Talbot Road and SE 189th Place 1 Renton, Washington Project No. T-1882-1 1 Terra Associates, Inc. A :. :.::.:..:................................. ..::...:.:.... : :. Prepared for: Environmental Development Corporation Bellevue, Washington 1 April 13, 1994 1 TERRA ASSOCIATES, Inc. °` Consultants in Geotechnical Engineering, Geology and Environmental Earth Sciences 1 April 13, 1994 Project No. T-1882-1 Mr. Thomas W. Ichelson Environmental Development Corporation P.O. Box 1574 Bellevue, Washington 98009 Subject: Geotechnical Report Summit Park Talbot Road and SE 189th Place Renton,Washington Dear Mr. Ichelson: As requested, we conducted a geotechnical engineering stud for the subject project. The attached g g Y J P J ' report presents our findings and recommendations for the geotechnical aspects of project design and construction. We used Triad Associates' preliminary grading and utility plan dated December 3, 1993 to prepare this report. New building layouts have been proposed as shown on Milbrandt Architects' Site Plan dated December 24, 1993. We understand that the site grades for the new building layouts will be similar to those Triad Associates previously presented. Our field exploration indicates the site is underlain at shallow depths by dense, sandy silt to silty sand glacial till soils. It is our opinion that the single and multi-family residences may be constructed using conventional spread footings placed on the competent native soils or on structural fill. Slab-on-grade floors and pavements may be constructed on properly conditioned recompacted native inorganic soils or structural fill. We appreciate the opportunity to be of service to Environmental Development Corporation during the preliminary design phase of this project. We look forward to being of continued service during the final design and construction phases. 12525 Willows Road, Suite 101, Kirkland, Washington 98034 • Phone (206) 821-7777 Mr. Thomas W. Ichelson April 13, 1994 We trust the information presented in this report is sufficient for your current needs. If you have any questions or require additional information,please call. Sincerely yours, ! ' 1TERRA ASSOCIATES,INC. ' Aaron McMichael Staff Engineer eodore J. Sche er, P.E. -- Principal Engineer otPiaes 6/18/95 AM/TJS:tm Project No. T-1882-1 Page No. ii �- TABLE OF CONTENTS Page a 1.0 Project Description 1 2.0 Scope of Work 2 3.0 Site Conditions 2 ' 3.1 Surface 2 3.2 Soils 3 3.3 Groundwater 3 1, 4.0 Discussion and Recommendations 4 4.1 General 4 4.2 Site Preparation and Grading 4 4.3 Structural Fill 5 4.4 Slopes and Embankments 6 4.5 Excavations 6 4.6 Detention Pond 7 LI 4.7 Foundations 7 4.8 Slab-on-grade Construction 8 4.9 Lower Level and Retaining Walls 8 4.10 Drainage 9 4.11 Utilities 10 4.12 Pavements 10 5.0 Additional Services 11 6.0 Limitations 11 Fi ures Vicinity Map Figure 1 Exploration Location Plan Figure 2 Soil Classification System Figure 3 Test Pit Logs Figures 4 through 8 Sieve Analyses Figure 9 Appendix Field Exploration and Laboratory Testing Appendix A Geotechnical Report Summit Park Talbot Road and SE 189th Place Renton, Washington r' i 1.0 PROJECT DESCRIPTION The Summit Park development is located east of the intersection of Talbot Road and SE 189th Place in Renton,Washington. The project location is shown on the attached Vicinity Map, Figure 1. Based on the r; site plan provided to us, we understand that the project will consist of 24 single family residences and 24 l condominium units. The condominium units will be grouped in three buildings with eight units each. Additional development will consist of construction of SE 189th Place, a storm water detention pond, a biofiltration swale, and associated utilities. Preliminary grading plans indicate that the buildings will step up the hillside from Talbot Road with ' approximately 3.5 to 5 feet of elevation change between buildings. Single family building foundations and SE 189th Place will likely be located within several feet of existing grades. Small fills may be required on the downslope sides and short retaining/foundation walls may be used on the upslope sides. Condominium building foundations will require larger cuts and fills which are estimated to be about two to ten feet. The detention pond northeast of the intersection of Talbot Road and SE 189th Street is expected to be excavated five to six feet below existing grades. The structures will be multi-level wood framed units. We understand that structural loads will be in the range of 20 to 40 kips for isolated columns, and two to four kips per foot for continuous bearing walls. Traffic volumes and loads accessing the development are expected to be light, consisting of passenger vehicles and light commercial trucks «nth occasional heavier loads in the form of moving trucks and trash removal vehicles. The recommendations presented in the following sections of this report are based upon the above design 6' features as we understand them. If actual features vary of if changes are made, we should be informed and requested to review actual design features. This will allow us to modify our recommendations as required. In any event,we should review final design drawings and specifications to verify that our recommendations have been properly interpreted and incorporated into the project design. April 13, 1994 Project No. T-1882-1 2.0 SCOPE OF WORK r' On March 22, 1994, we excavated ten test pits to depths of 10 to 15 feet below existing surface grades. Using the information obtained from the subsurface exploration, we performed analyses to develop geotechnical recommendations for design and construction. Specifically, this report addresses the i, following: • Soil and groundwater conditions 0 Suitability of native soils for use as fill Recommendations for import fill material Site preparation and grading • Foundation support alternatives • Earth pressure parameters for basement or retaining wall design' 0 Slab-on-grade support • Drainage • Utilities • Pavements 3.0 SITE CONDITIONS r 1 t 3.1 Surface The site consists of a westerly sloping rectangular parcel measuring about 1,285 feet from east to west and 438 feet from north to south. A wetland has been identified in the middle third portion of the site. The property is bordered by Talbot Road along the west and lightly developed rural pasture and forest lands to the north, east, and south. The site previously consisted of two parcels of approximately equal size. The parcel to the north contains an abandoned house. The parcel to the south contains an occupied single family residence with a separate garage. The lower western portion of the property consists of pasture and brush, while the upper eastern portion is wooded. The ground surface adjacent to the east side of the abandoned house was saturated due to water flowing from a garden hose. The hose appears to continue upslope to the east and most likely taps a groundwater spring. The ground surface east of the house is also saturated. Seepage appears to be flowing onto the proposed development area from the wetland area at higher elevations to the east. We noted a small stream channel flowing across the northeast corner of the site. There appears to be a natural drainage swale along the south property line. Surface water flow within this area was obscured by heavy blackberry vegetation. Page No. 2 April 13, 1994 Project No. T-1882-1 The portion of the site proposed for development slopes gently downward to the west at a grade of j ' approximately 13 percent. The elevation change across the site from east to west is approximately 65 feet. I 3, 2� Soils We explored the site by excavating ten test pits at the locations shown on the attached Exploration Location (' Plan, Figure 2. We generally encountered 6 to.12 inches of topsoil in the test pits. However, Test Pit TP-7 encountered about 24 inches of topsoil. Beneath the topsoil, our test pits encountered glacially deposited weathered and unweathered till soils. The unweathered till consists of two to four feet of loose to medium dense, sandy silt to silty sand soils. Underlying these soils, the test pits encountered unweathered till soil consisting of dense to very dense, silty sand with gravel and occasional 4 to 12 inch diameter cobbles. In -, general, till soils continued to the maximum depths explored, 10 to 15 feet. However, at Test Pits TP-2 and TP-7, what appears to be advanced outwash consisting of cleaner sand with a trace of gravel was found underlying the till. Based on the Soil Conservation Service (SCS) classification, the on-site soils are mapped in the Alderwood series. Alderwood soils are classified as Hydrologic Group C. Hydrologic Group C soils have slow infiltration characteristics and impede generally downward movement of water. L r; 3.3 Groundwater i We observed slight to moderate groundwater seepage in all of the test pits excavated on-site. The groundwater seepage generally appeal to be perched above the denser underlying soil at depths of 1.5 to 4 feet. However, at Test Pit TP-7 we encountered moderate to heavy groundwater seepage within the advanced outwash soils at a depth of nine feet. ., The ground surface along the eastern portion of the development was wet and soft during our field work. It appears that seepage from the wetland is flowing downslope on to the proposed area of construction. This seepage will likely enter the excavations. The amount of seepage flow into the excavations and the potential impacts will depend on the time of year the excavations are completed. The amount of seepage P P p Y P P� will be at its highest during extended periods of heavy precipitation and during the wet winter months. The test pi ts is were e e not allowed to remain open for an extended period of time,which would have allowed for a more detailed evaluation of the groundwater observed. Fluctuations in groundwater seepage levels should be expected on a seasonal and annual basis. Typically, groundwater seepage reaches maximum levels during and shortly following the wet winter months. Page No. 3 ' April 13, 1994 Project No. T-1882-1 4.0 DISCUSSION AND RECOMMENDATIONS ' 4.1 General ' based on our study, in our opinion, there are no geotechnical constraints which would preclude development of the proposed residential plat as planned. The primary geotechnical consideration for -' development of the site will be the planned cuts and fills and control of groundwater seepage. Single and multi-family residences may be constructed using conventional spread footing foundations ( placed on competent native soils below the upper 18 to 24 inches of surficial soils. Alternatively, if 1, required by desired final building elevations, structural fill placed and compacted above these native soils can be used to support the building foundations. Floor slabs may be similarly supported. We encountered perched groundwater within the upper 1.5 to 4 feet of the existing ground surface. Therefore,you should expectlight tQmoderate groundwater seepage onio the planned slope cuts, and in the detention pond and utility excavations. In our opinion, a predominant portion of the seepage flowing onto the site can be controlled by installing a.drainage swale/interceptor trench_along_the-east-perimeter of the construction area. We also noted groundwater seepage flowing from a garden hose in the location of the abandoned house. This discharge appears to be flowing from an upslope spring. We recommend determining the source of f the flow and providing appropriate permanent drainage as required to prevent continued flow on-site. The native soils we encountered at the site contain a significant amount of fines and will be difficult to compact as structural fill due to their above-optimum moisture content. If grading activities will take place during the winter or spring season, the owner should be prepared to import free-draining granular material I' for use as structural fill and backfill. Detailed recommendations regarding the above issues and other geotechnical design considerations are provided in the following sections. These recommendations should be incorporated into the final design drawings and construction specifications. 4.2 Site Preparation and Grading To initially prepare the site for construction, it will be necessary to remove all vegetation, organic surface soils, and other deleterious materials. Based on our study, surface strip in -depths_ofabout 6 to 12 inches should be expected to remove organic topsoil, however, localized stripping depths approaching 24 inches should be expected. Stripped vegetation debris should be removed from the site. Organic topsoil will not be suitable for use as structural fill, but may be used for limited depths in non-structural areas or for landscaping purposes. Page No. 4 ' April 13, 1994 Project No. T-1882-1 Once clearing and stripping operations are complete, cut and fill operations can be initiated to establish desired building grades. To establish planned building and roadway subgrades, cuts and fills about two to eight feet deep will be completed. Prior to placing fill, we recommend proofrolling all exposed surfaces to determine if any isolated soft and yielding areas are present. We noted that the near-surface soils were lobse to depths of about two to three feet. Where loose soils exist, they should be recompacted in-place. If ' this is not possible, loose soils should be overexcavated to firm bearing soils in order to expose soils suitable for support of building foundations, slab-on-grade floors, or structural fill. ' If excessively yielding areas are observed at pavement subgrade elevations, they should be cut to firm bearing soils and filled to grade with structural fill. If the depth of excavation to remove unstable soils is excessive, use of geotextile fabric such as Mirafi 500X or equivalent in conjunction with structural fill could be considered. As a general rule, a minimum of 18 inches of a clean, granular structural fill placed % over the geotextile fabric should establish a stable bearing surface. We should observe all proofrolling operations. We also recommend field evaluations at the time of i construction to verify stable subgrades. L J4.3 Structural Fill Our study indicates that the native soils contain a significant percentage of fines (silt and clay size particles). Accordingly, the ability to use the native soils from site excanns ac ctnlctural fill will depend _ on their moisture content and the_prevailing weather conditions.atthe_time site grading activities take place. Laboratory testing indicates that at the time of our study, the soil's moisture content was above optimum. In our opinion, these soils will not be suitable for use as structural fill without modification. In order to use these materials as structural fill, drying by aeration during dry weather conditions or using an additive such as cement or lime to stabilize the soil should be considered. If grading activities are planned during the wet winter/spring season or if they are initiated during the summer and extend into fall and winter, the owner should be prepared to import wet weather structural fill. For this purpose, we recommend importing a granular soil which meets the following grading requirements: Maximum Aggregate=6 inches U.S. Sieve Size Percent Passing 44 75 maximum #200 5 maximum* *based on the 3/4 inch fraction , Prior to use, Terra Associates should examine and test all materials imported to the site for use as structural fill. Page No. 5 ' April 13, 1994 Project No. T-1882-1 Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of 95 percent of the soil's maximum dry density, as determined by Test Designation ASTM D- 698 (Standard Proctor). The moisture content of the soil at the time of compaction should be within two percent of its optimum, as determined by the same referenced standard. In non-structural areas or for liackfill in utility trenches below a depth of four feet, the degree of compaction could be reduced to 90 percent. 4.4 Slopes and Embankments The preliminary grading plan indicates that fill slopes may be necessary near the transition between the condominium buildings. Rockeries may also be used to make grade changes between buildings. Where t�rockeries'are planned to face fills greater than four feet in height, we recommend using geogrids to st rcru ally reinforce. the fill. We can prove a recommendations for the structurally reinforced fill if required. All permanent cut and fill slopes should be graded with a finished inclination of no greater than 2:1 (Horizontal:Vertical). When grading is complete, slope faces should be thoroughly compacted and track- walked and then appropriately vegetated or provided with other physical means to prevent erosion. All fill placed for embankment construction should meet the structural fill requirements as described in the Site Preparation and Grading section of this report. The site slopes are about 13 percent in grade, therefore, benching the structural fills into the native slope face should not be necessary. However, we recommend e toe of the embankment fills be keyed into the competent native soils. The key should have a minimum i depth of two feet and a mui<imum width of six feet. In addition, we recommend that the toe of the embankment slopes be provided with a drain to collect potential seepage and prevent hydrostatic pressure development. Based on conditions observed, the drain pipe invert should be established at a depth of three feet below existing surface grades. Mid-slope drains beneath the embankment fills may also be necessary if seepage areas are observed after site clearing is complete. 4.5 Excavations All excavations at the site associated with confined spaces, such as utility trenches and lower building levels, must be completed in accordance with local, state, or federal requirements. Based on current Occupational Safety Health Administration (OSHA) regulations, soils within the upper five feet of the surface would be classified as Group C soils. Below this level, soils fall into a Group A category. For excavations more than four feet in depth, the side slopes Within-the-upper-frvaca-sh©uld-be-laid-back at a inimumslope inclination of 1.5:1. Below this level, side slopes should be completed with a gradient of 0.75:1 or flatter. If there is insufficient room to complete the excavations in this manner, you may need to consider using temporary shoring to support the excavations. Page No. 6 April 13, 1994 Project No. T-1882-1 Groundwater seepage shouldd be-anticipated--va'thin._excavations extending below depths of 1.5 feet and below existing surface grades. The volume of water and rate of flow into the excavation should be slight to moderate, and is not expected to impact the stability of the excavations when completed as described above. In our opinion, conventional sump pumping procedures within utility trench excavations of eight feet and (' shallower should be capable of maintaining a relatively dry excavation for construction purposes. As identified at Test Pit TP-7, heavier groundwater flows may be encountered at deeper excavations that f extend into apparent outwash soils. If deep utility excavations are planned, the contractor should be prepared to dewater using isolated wells or well points before excavation, if required. The above information is provided solely for the benefit of the owner and other design consultants, and should not be construed to imply that Terra Associates assumes responsibility for job site safety. It is understood that job site safety is the sole responsibility of the project contractor. 4.6 Detention Pond A storm water detention pond is planned adjacent the entrance to the site on SE 189th Place. We anticipate that the pond will be excavated approximately five to seven feet below existing grades. Interior embankment slopes for the pond should be no steeper than 3:1 exterior slopes can be graded to 2:1. If fills are used to construct perimeter berms,they should be compacted as a structural fill. We encountered perched groundwater seepage within the upper weathered soil zone, between 1.5 to 4 feet of the ground surface. Therefore, slight to moderate groundwater seepage should be expected to flow into the detention pond excavation. This seepage may reduce the detention pond's capacity to hold storm water from other areas of the site. The flow rate and/or volume of groundwater seepage into the detention pond will depend on many factors, including the height of the seepage face exposed by the excavation. Assuming that the upper weathered zone is fully saturated and the pond excavation completely penetrates this upper zone into the underlying dense till soil, a cursory analysis indicates that total seepage into the pond of .2 to .5 gpm could be expected. This analysis assumes a flow gradient of 0.13, a soil permeability of .0001 cm/sec, and 250 lineal feet of exposed seepage face. 4.7 Foundations Spread Footings With construction grades as planned, foundations may be supported on competent native soils or on structural fills placed above competent native soils. Foundations exposed to the weather should be 4 minimum of 18 inches below final exterior grades. Interior foundations can be constructed at any convenient depth.below the floor slab. Building foundations should be setback a minimum distance of ten !� feet from the crest of the constructed western site slope. Page No. 7 April 13, 1994 Project No. T-1882-1 Foundations can be dimensioned for a net allowable bearing capacity of 2,000 pounds per square foot (psf). For short-term loads such as wind and seismic, a 1/3 increase in this allowable capacity can be used. With structural loading as anticipated and this bearing stress applied, estimated total settlements fall in the range of 1/2 inch and less. For proportioning foundations to resist lateral loads, a base friction coefficient of 0.35 can be used. Passive earth pressure development acting on the side of the footing and buried portion of the foundation ' stem wall can also be considered. We recommend calculating this lateral resistance using an equivalent fluid weight of 300 pounds per cubic foot (pcf). We recommend not including the upper one foot of soil, ' which can be affected by weather or disturbed by future grading activity, in this computation. This value assumes the foundation will be constructed neat against competent native soil or backfilled with structural fill as described in the Site Preparation and Grading section of this report. The values recommended ( include a safety factor of 1.5. Ir Slab-on-grade Construction Slab-on-grade floors may be supported on a subgrade prepared as recommended in the Site Preparation and Grading section of this report. Immediately below the floor slab, we recommend placing a four inch layer of clean, free-draining sand or gravel that has less than three percent fines passing the No. 200 sieve. This precaution will guard against wetting of the floor slab due to capillary movement of water through the ' underlying soil. Where moisture by vapor transmission is undesirable, a durable polyethylene vapor barrier should also be ' installed. This vapor barrier should be placed on an initial four inch layer of capillary break material. This may be covered with one to two inches of clean, moist sand to guard against damage during construction and to aid in uniform curing of the concrete floor. t 4.9 Lower Level and Retaining Walls The magnitude of earth pressures developing on lower level walls or retaining walls will depend, mi art on � P P g g P P , the wall backfill. We recommend placing and compacting wall backfill as structural fill. Below improved areas such as pavements or floor slabs,the backfill should be compacted to a minimum of 95 percent of the soil's maximum dry density, as deternuned by Test Designation ASTM-D-698 (Standard Proctor). In I; unimproved areas,the relative compaction can be reduced to 90 percent. Basement and retaining walls should be provided with continuous drainage to reduce the potential for hydrostatic pressure build-up behind them. A 12 inch wide zone of free-draini. gravel should be placed behind all walls. The final 12 to 18 inches may be capped with native soils. A,_puffim ed>_Wipe sh ld be placed at the base of the wall to collect water from the free-drainage zone and to discharge it away from the walls. As an option, a drainage board material such as Miradrain may be used to replace the 12 inch free- drainage gravel zone. Use of other appropriate drainage procedures and materials may be feasible. These should be discussed with Terra Associates, Inc. personnel at the time of construction. Y. Page No. 8 ' April 13, 1994 Project No. T-1882-1 With proper wall backfill and drainage, we recommend designing unrestrained walls for an active earth pressure imposed by an equivalent fluid weighing 35 pcf. For restrained walls, an additional uniform lateral pressure of 100 psf should be added. These values assume a horizontal backfill condition, and that no other surcharge loading such as traffic, sloping embankments, or adjacent buildings will act on the wall. ' If such conditions will exist then the imposed loads must be included in the wall design. Friction at the base of foundations and passive earth pressures will provide resistance to these lateral loads. Values for these parameters are provided in the Foundations section of this report. f 4.10 Drainage Surface Final exterior grades should promote free and positive drainage away from the building sites at all times. Water must not be allowed to pond or collect adjacent foundations or within the immediate building area. f We recommend providing a minimum drainage gradient of three percent for a minimum distance of ten feet from the building perimeters, except in paved locations. In paved locations, a minimum gradient of one percent should be provided unless provisions are included for collection and disposal of surface water adjacent the structures. We recommend instalh g_a_permanent__drainage--swa1e along the-- e4stqnL perimeter of the proposed construction area. This Swale would intercept surface and subsurface perched seepage flowing down slope to the west from the adjacent wetland area. It appears that the intercepted seepage could be directed under gravity flow around the site to a drainage swale forming the south property line. We recommend that the swale be bottomed at a minimum depth o___f three feet below existing grades. As an alternative, a gravel filled interceptor drain can be constructed. = In addition, surface water must not be allowed to flow uncontrolled over the crest of any slopes and embankments. Preferably, surface water should be directed away from the slope crests to a point of collection and controlled discharge. If site grades do not allow for directing surface water away from the slopes,then water should be collected and tightlined do-,Am the slope face in a controlled manner. Subsurface In addition to the drainage systems already discussed, to guard against groundwater seepage into crawl spaces and beneath slab-on-grade floors, we recommend installing perimeter foundation drains. The foundation drains should consist of four inch diameter perforated pipe surrounded by at least six inches of pea gravel or similar drainage rock. Roof gutter downspouts should be separately tightlined to an appropriate discharge point. Page No. 9 ' April 13, 1994 Project No. T-1882-1 ' 4.11 Utilities Utility pipes should be bedded and backfilled in accordance with American Public Works Association (APWA) specifications. At minimum,trench backfill should be placed and compacted as structural fill, as ' dgscribed in the Site Preparation and Grading section of this report. As noted, soils excavated on-site are moisture-sensitive and will be difficult to use as backfill material in their present condition and during wet weather. Therefore, drying back or other means to condition the material will probably be necessary to facilitate proper compaction. If utility construction takes place during the winter season, you should be prepared to import suitable wet weather structural fill for use in utility trench backfilling. 4.12 Pavements Pavements should be constructed on subgrades prepared as described in the Site Preparation and Grading section of this report. However, regardless of the degree of relative compaction achieved, the subgrade must be in a firm and relatively unyielding condition prior to paving. Proofrolling the subgrade with heavy construction equipment should be completed to verify this condition. The pavement design section is dependent upon the supporting capability of the subgrade soils and the traffic conditions to which it will be subjected. As we understand, traffic will mainly consist of light passenger and commercial vehicles with only occasional heavy traffic in the form of moving trucks and trash removal vehicles. Based on this information, with a stable subgrade prepared as recommended, we recommend the following pavement sections: `, • Two inches of asphalt concrete (AC)over four inches of crushed rock base (CRB) • Two inches of AC over three inches of asphalt treated base(ATB) l' Paving materials used should conform to Washington State Department of Transportation (WSDOT) specifications. ' Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their supporting capability. For optimum pavement performance, surface drainage gradients of no less than two percent are recommended. Also, some degree of longitudinal and transverse cracking of the pavement surface should be expected over time. Regular maintenance should be planned to seal cracks when they !, occur. Page No. 10 ' April 13, 1994 Project No. T-1882-1 5.0 ADDITIONAL SERVICES Terra Associates, Inc. should review the final design and specifications in order to verify that earthwork and foundation recommendations have been properly interpreted and implemented in project design. Terra Associates, Inc. should also provide geotechnical services during construction. The purpose of this is to observe compliance with the design concepts, specifications, and recommendations. It will also allow for design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. We should provide the following services during construction: • Examine site excavation and seepage conditions • Observe subsurface drainage installations • Observe proofrol1mg of subgrades ' • Observe earthwork activities and perform density testing of structural fill and utility trench P tY g tY backfill 1' We request a minimum of two working days'notice be given to schedule our services during construction. ( 6.0 LIMITATIONS ' This report is the property of Terra Associates, Inc. and was prepared in accordance with generally accepted geotechr&al engineering practices. This report is intended for specific application to the Summit Park project, and for the exclusive use of Environmental Development Corporation and their authorized representatives. No other warranty, expressed or implied, is made. j' The analyses and recommendations presented in this report are based upon data obtained from the test pits ii advanced on-site. Variations in soil conditions can occur, the nature and extent of which may not become { evident until construction. If variations appear evident, Terra Associates, Inc. should be requested to ' reevaluate the recommendations in this report prior to proceeding with construction. i' i� t Page No. 11 ' T- 167 fS P 45TH ST 2 O � � o 0 •U UIY ' V Q SE 187TH ST o � U •h o � _PROJECT Q Sl TE r ' SE 190TH ST SE 190TH ST S 55TH ST SE 192ND ST Ln OF rn K/iyC Cp' E.NTON � UNTY E d� TERRA VICINITY MAP` Y' SUMMIT PARK ASSOCIATES RELATOR WASF INGTON Geotechnical Consultants Proj. No. 1882-1 Date 3-94 Figure 1 TP-4C6> ❑ TP-3 ❑ { { TP-2 ❑ - ' TP-5 ❑ TP-6 ❑% f 1 U/ 1 w � - /� V � l� TYP. 8 UNIT BLDG. 4c, WETLANDS Q C) TP-1 ❑ O TP-10 ❑ •�P ) �: LEGEND O Q Q TEST PIT LOCATION TP-1 ❑ S. E. 1 8 9 k �k. t TP-7 ❑ 40 0 40 1"=40' TP-9 ❑ { { scale feet XT ;+ TP-8 ❑ �+ r Y 14- TERRA EXPLORATION PLAN SUMMIT PARK - ASSOCIATES RENTON, WASHINGTON Geotechnical Consultants Proj. No.1882-1 Date 3-94 Figure 2 MAJOR DIVISIONS LETTER GRAPH TYPICAL DESCRIPTION SYMBOL SYMBOL GRAVELS Clean i GW •' Well graded gravels, gravel-sand mixtures, little Gravels '•q q Y or no fines. 0 (less than I ; • • • • • Poorly-graded gravels, gravel-sand mixtures, little J co N More than 5% fines) GP • ' • ' or no fines. p 50% of coarse ' 0 W � fraction is GM � � Silty gravels, gravel-sand-silt mixtures, non- (1 in I > larger than No. Gravels plastic fines. z 4 sieve. with fines GC • •�' / Clayey gravels, gravel-sand-clay mixtures, plastic Q o • fines.o 0 N SANDS Clean Well-graded sands, gravelly sands, little or Sands SW no fines. w cz <_`., . r More than (less than ,Ifrrr{; Poorly-graded sands or gravelly sands, little Q 4- 50% of coarse 5% fines) SP f ::::;:%:r<;<;»::< or no fines. O fraction is U o smaller than S M Silty sands, sand silt mixtures, non plastic fines. No. 4 sieve. Sands with fines SC Clayey sands, sand-clay mixtures, plastic fines. Inorganic silts and very fine sands, rock flour, silty or N SILTS AND CLAYS ML clayey fine sands or clayey silts with slight plasticity. J_ `D O 10 > CL Inorganic clays of low to medium plasticity, gravelly L; Liquid limit is less than 50% clays. sandy clays, silty clays, lean clays. w ae I QL i i '�'�� Organic silts and organic clays of low plasticity. Z M < �z Inorganic silts, micaceous or diatomaceous fine O SILTS AND CLAYS MH sandy or silty soils, elastic. z Liquid limit is greater than 50% _CH — Inorganic clays of high plasticity, fat clays. O { i I T Organic clays of medium to high plasticity, organic silts. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. DEFINITION OF TERMS AND SYMBOLS J Standard Penetration 2" OUTSIDE DIAMETER SPLIT uj Density Resistance in Blows/Foot T SPOON SAMPLER 2.4" INSIDE DIAMETER RING SAMPLER Very loose 0 4 Loose 4-10 OR SHELBY TUBE SAMPLER ° Medium dense 10-30 P SAMPLER PUSHED 0 Dense 30-50 * SAMPLE NOT RECOVERED Very dense >50 Q WATER LEVEL (DATE) WATER OBSERVATION STANDPIPE Standard Penetration C TORVANE READINGS, tsf y Density Resistance in Blows/Foot qu PENETROMETER READING, tsf UVery Soft 0 2 W MOISTURE, percent of dry weight o Soft 2-4 pef DRY DENSITY, pounds per cubic foot J Medium stiff 4-8 LL LIQUID LIMIT, percent Stiff 8-16 U) Very stiff 16-32 PI PLASTIC INDEX Hard >32 N STANDARD PENETRATION, blows per foot SOIL CLASSIFICATION SYSTEM TERRA Summit Park PON ASSOCIATES Renton, Washington Geotechnical Consultants Proj. No. T-1882-1 Date 3/94 Figure 3 Test Pit No. TP-1 Logged by: AM Approximate Elev. 203 Date: 3-22-94 Depth (ft.) USCS Soil Description W 0 Graph escr M fa inches black topsoil) 28.1 .. . ... ... Brown,gravelly, silty SAND, moist, loose to medium dense. ........... 16.2 ...... .... ... .. .... ........ ...... . ..... .. .... ........ .. ... ........ ................. ............. ........... .... 5 Gray, silty SAND with fine gravel, damp, dense to XX very dense. 12.4 X. 10.4 10 Test pit terminated at 10 feet. Slight to moderate groundwater seepage at 3 feet. is Test Pit No. TP-2 1 Logged by: AM Approximate Elev. 207 Date: 3-22-94 Depth (ft.) Gsaph Soil DescriptionWN 0 inches bla ck ack topsoil) tvt Light brown, silty SAND trace gravel, moist, loose to medium 17.4 dense. 13.3 X -X Tan to gray, silty SAND trace gravel and occasional 6-18 inch 5 diameter cobbles and boulders, damp, dense to very dense. 14.9 X m Gray, poorfy-graded fine SAND with silt, damp to moist, dense. 23 10 sP .5 M Test pit terminated at 12 feet. Slight to moderate groundwater seepage at 1.5 feet. 15 Slight caving at 10 feet. TEST PIT LOGS ............... TERRA Summit Park ,, ASSOCIATES Renton, Washington Geotechnical Consultants Proj. No. T-1882-1 I Date 3/94 Figure 4 Test Pit No. TP-3 Logged by: AM Approximate Elev. 177 Date: 3-22-94 Depth USCS/ Soil Description W Graph 0— (12 inches black topsoil) Brown, sandy SILT trace organics, moist, loose. 23.4 -------------- Brown to tan, mottled silty SAND some gravel, damp, medium 21.7 dense. Red 5 dish-brown to gray, silty SAND with gravel, damp, dense to very dense. 12.8 ...... . ...... .......... 18.6 ... . . . . ... ... . . . ..... ... . . . . .. Test pit terminated at 13 feet. 15 Slight groundwater seepage at 2.5 feet. Test Pit No. TP-4 r, Logged by: AM Approximate Elev. 156.5 Date: 3-22-94 j' Depth USCS/ Soil Description W Graph M 0 (12 inches black topsoil) Tan, mottled silty SAND, moist to wet, loose. 16.3 Reddish , silty SAND trace gravel, damp, medium dense 18.2 *39%SILT to dense. 5 18.0 4-12 inch diameter cobbles below 6 feet. .. .. ........... Very dense at 8 feet. 10 16.2 Percent of silt determined by minus 200 sieve wash. 23.2 *19%SILT 15 Test pit terminated at 15 feet. Slight seepage at 1.5 feet. TEST PIT LOGS ....... ..... TERRA Summit Park ............. ASSOCIATES Renton, Washington Geotechnical Consultants Proj. No. T-1882-1 � Date 3/94 R gu re 5 Test Pit No. TP-5 Logged by: AM Approximate Elev. 156 Date: 3-22-94 Depth (ft.) Gsaph Soil Description M 0— M (6 inches black topsoil) SM Tan, mottled sandy SILT to silty SAND some gravel, moist, loose. 21.0 Tan. silty SAND some gravel, moist to damp, medium dense to dense. . ........... 17.5... ... ...... 5 . . .... ...... .... ....... Reddish-tan, silty SAND some gravel, damp, dense to very dense. 16.6 ..... ....... 10 Occasional -6 inch diameter cobbles and 12-18 inch diameter 4 boulde rs below 11 feet. 16.7 1.16.4, Test pit terminated at 15 feet. Slight groundwater seepage at 1.5 feet. Test Pit No. TP-6 Logged by: AM Approximate Elev. 166 Date: 3-22-94 Depth (ft.) USCS/ Soil Description W 0— Graph M (12 inches black topsoil) Im Tan, mottled sandy SILT to silty SAND trace gravel, moist, 20.1 loose to medium dense. 5 Light brown to reddish, silty SAND some gravel,damp, moist, 16.4 dense. ....... ....... 16.8 . ... ...... Very dense at 8 feet. ........... TX X 10 ........... 20.4 Test pit terminated at 12 feet. Slight to moderate groundwater seepage at 1.5 feet. 15 TEST PIT LOGS .................. .................. TERRA Summit Park ASSOCIATES Renton, Washington Geotechnical Consultants Proj. No. T-1882-1 Date 3/94 Figure 6 Test Pit No. TP-7 Logged by: AM Approximate Elev. 193 Date: 3-22-94 Depth USCS/ W i Soil Description M 0 (24 inches black topsoil) Tan brown to gray, mottled silty SAND with gravel, moist, 22.0 medium dense to dense. 13.7 *38%SILT �' M Very dense at 6 feet. i' 13.0 Blue gray, fine SAND with silt and gravel, waterbearing, 10 SPS very dense. 10.9 Test pit terminated at 11 feet. Slight groundwater seepage at 2.5 feet. Moderate to heavy groundwater seepage at 9 feet. 15 Test Pit No. TP-8 �' Logged by: AM Approximate Elev. 170 Date: 3-22-94 Depth Graph Soil Description (6 inc hes black topsoil) Light brown, mottled silty SAND, moist, loose. 19.4 *40%SILT 'X X Brown, silty SAND with gravel, moist to damp, medium dense ............... to dense. 15.3 ......... ..... .. .......... 5 Very dense at 6 feet. 10 11.81 Test pit terminated at 10 feet. Slight groundwater seepage at 3 feet. 15— TEST PIT LOGS TERRA Summit Park ASSOCIATES Renton, Washington Geotechnical Consultants Proj. 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We explored subsurface soil conditions at the site by excavating ten test pits to a maximum depth of 15 feet below existing grade. Test pit locations are shown on Figure 2. The test pit locations were approximately determined by measurements from existing property lines and building corners. The Test Pit Logs are presented on Figures 4 through 8. (' A geotechnical engineer from our firm conducted the field exploration and classified the soil conditions encountered, maintained a log of each test pit, obtained representative soil samples, and observed pertinent site features. All soil samples were visually classified in accordance with the Unified Soil Classification System described on Figure 3. ' Representative soil samples obtained from the test pits were placed in closed containers and taken to our laboratory for further examination and testing. The moisture content of each sample was measured and is reported on Figures 4 through 8. In addition, the percent of soil fines (silt and clay particles) was ' determined on several samples. These results are also reported on the test pit logs. i' Project No. T-1882-1