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HomeMy WebLinkAboutMisc 4 of 4Talbot Ridge Estates L07SR012, First Review Comments All page references are based on 2005 King County Surface Water Design Manual (KCSWDM), 1993 King County Road Standards (KCRS) and King County Codes (KCC). HEARING EXAMINER'S CONDITIONS: 1. State how to comply with the TDR certificate on cover sheet per condition 4. 2. Add compliance notes on plans per conditions 9, 10 and 21. 3. Add road variance number L05VO066 and variance conditions and reduced SSD on the frontage improvement of SE 192"d Street per condition 11 c. GENERAL AND TIR COMMENTS: 1. Provide a horizontal control plan which shows road classifications, lot dimensions, road horizontal alignment data, radii of curb returns, table and description of tracts, and signature of licensed surveyor. 2. Provide two ADA ramps at curb return of intersection. See policy from the County Road Engineer. On site tract D shall be included on the flow control design. Provide KCRTS analysis on onsite runoff bypass and offsite bypass per SWDM 1.2.3.3. The release rate of runoff from the vault shall be reduced to account for all onsite and offsite bypass. 4. Provide flow frequency analysis and flow duration curves of the inflow and outflow of the vault. 5. Provide point of compliance analysis to show flow control compliance on all bypass runoff. 6. Provide catch basin on curb line along SE 192"d Street where spacing of catch basins shall be provided per KCRS 7.04. 7. Show the 7' power easement record no. 5678862 and building setback line BSBL on an overall drainage plan. 8. Provide turnpike shoulder on rural neighborhood collector instead of asphalt thicken edge shoulder per KCRS Dwg. Nos. 1-005 and 2-024. i t Label saw cut of pavement at the fog line. If there is no fog line, saw cut shall be at the edge of existing travel way. Existing width of shoulder shall be restored for road widening. Therefore a full section of road way shall be provided to show the existing and developed conditions. ' ' 10. a. Water quality treatment on frontage road improvement of SE 192"d Street and 102"d Ave SE is required because the project does not comply with the Transportation Redevelopment Projects condition 2a per page 1-58 of SWDM, where the total new impervious surface within the project limits is less than 50% of the existing impervious surface. b. If runoff form frontage improvement is less than 50% of the developed runoff, and can be collected to the plat drainage facility, then basic water quality treatment is required. Otherwise, enhanced basic water quality treatment is required for the frontage runoff alone per page 1-60 and 1-61 of SWDM. c. Storm filter is commonly used on right-of-way for water quality treatment. Contact Kate Rhoads of DNR at 206-296-8046 for the application and options of water quality treatment. 11. Rockeries are not allowed in County storm tract per County policy. 12. CPE pipe is not allowed per road standards. Use lined corrugated polyethylene (LCPE) pipe to replace CPE pipe per KCRS 7.03. 13. Provide bond quantity worksheet. 14. Contact Janise Fessenden at 206-296-7010 to finalize the name of plat road A. 15. Number the plan sheet in a simple and common one to fourteen numerical order to save time on checking. 16. Specify the type, size and location of individual lot BMP flow control for each lot on plan. 17. Provide structural plan for the vault. DRAWING COMMENTS: Sheet 1 (C1.01) C yam' J._ -P. • _ fG 2 1. On the third block at the upper right corner of the sheet, fill in dates of preliminary plat approval and expiration. Specify whether the site is erosion sensitive per SWDM appendix D. Sheet 2 W2.01) 1. Delete all clearing and grading on neighboring private lots, or provide construction easement from neighboring lots 15, 16 and 24 along SE 192"d Street. 2. Provide TESC for the construction of outfall IA and CBl where will get a lot of runoff from the slope. Sheet 3 C3.01 { �4. Private access tract (PAT) shall conform to urban minor access road per KCRS ✓ 2.09.B. Provide a 25 ft minimum right-of-way line radius at PAT per KCRS 2.10.A.4. 2. Provide sidewalk easement on lot 22. 03. Revise note to provide 27 ft pavement width to the east of the curb and sidewalk on 102" d Ave SE from STA 10+00 to STA 13+00, 4. Rockery is not allowed at drainage tract per County policy. 5. Label a dash line at the south of the site 6. 7. Rockery higher than 6 ft requires structural review. Rockery within the 5 ft building setback line BSBL shall be limited to 6 ft maximum. S. Add pavement overlay notes as follows: KCRS 4.01 provides minimum paving standards whenever an existing road is widened. F. STREET WIDENING/ADDING TRAVELED WAY TO EXISTING ROADS 1. When an existing asphalt paved street is to be widened, the edge of pavement shall be saw cut to provide a clean, vertical edge for joining to the new asphalt. After placement of the new asphalt section, the joint shall be sealed and the street overlaid one inch, plus a prelevel course, full width throughout the widened area. The requirement for overlay may be waived by the Engineer or Reviewing Agency based on the condition of existing pavement and the extent of required changes to channelization. 3 Sheet 4 (C3.02) 1. Provide construction easements for driveway connection to Lots 16 and 24 r Provide a full width road section for SE 192"d Street to ensure there is enough space for future full width development. Show existing edges and widths of pavement and shoulder. Add title Section A -A. Asphalt hicken edge is not allowed, provide gravel shoulder. ...._ . 3 "d i .. i Provide turnpike shoulder on the north side of SE 192 Street (rural neighborhood collector) per KCRS Dwg. Nos. 1-005 and 2-024. Show and justify the impact and conveyance of road improvement runoff to the affected neighboring lots along SE 192"d Street on TIR. Provide details on the existing drainage conveyance system along both sides of the frontage, which shall be checked to prevent flooding to the affected lots. �;4v 4. Concrete ramp shall be provided at the end of sidewalk instead of asphalt ramp per Dwg. 4-004 of KCRS. 5. Revise call out to contact KCDOT for road sign relocation. 6. Pending review from KCDOT on road reconstruction. 7. Water quality treatment may be required. Sheet 5 (C3.31) '�. r.. Show existing widths of pavement and shoulder on the Section of 102"d Ave SE. I. 2. Label saw cut of pavement at the fog line. If there is no fog line, saw cut shall be at the edge of existing travel way. Existing width of shoulder shall be restored for road widening. Therefore a full section of road way shall be provided to show the existing and developed conditions. 3. Provide turnpike shoulder on the east side of 102"d Ave SE (rural neighborhood collector) per KCRS Dwg. Nos. 1-005 and 2-024. 4. Revise road section to provide 27 ft pavement width to the east of the curb and sidewalk on 102"d Ave SE from STA 10+00 to STA 13+00. 5. Provide a road crown section on private access tract. 6. Double check whether Tract B is joint use driveway or private access tract. 7. Delete detail of asphalt thickened edge. r 4 8. Use Fig. 3-011 on 2007 KCRS to replace Fig. 3-007 on the curb ramp detail. The minimum width of ramp shall be 4 ft instead of 3 ft. 9. Provide structural calculation for design of rockery with geogrid. Sheet 6 (C4.01) 1. Provide one catch basin between STA 10+00 to STA 12+00 per KCRS 7.04.A. 2. Revise the stopping sight distance on Road A to provide downgrade adjustment per KCRS 2.12. (�' Provide detail on size and capacity whether a ditch or tight line will convey runoff form outfall 1 A to downstream. Justify the conveyance capacity on T1R. Sheet 7 (C4.31) 1. Provide a complete plan to show the whole drainage tract, setback of vault from the tract and adjacent building setback line. 2. Setback to tract for vault shall be 5 feet; adjacent building setback lines shall be + ; 10 feet per setbacks requirement on page 5-36 of SWDM. 3. Flow path on wet vault shall not be hindered by internal walls within the vault. Provide a flow path on the wet vault that has a length to width ratio of 3:1 per wetpool geometry item 6 on page 6-74 of SWDM 6.4.1.2. Y ' ram. --?- �, , (4. ,,The top of 12" inlet pipe to the wetvault shall be submerged 1 ft below the �•' ' t' ` maximum water quality elevation. The invert of the inlet pipe shall have a f { ` minimum of 3 feet from the vault bottom not including sediment storage per they: inlet and outlet requirement on page 6-85 of SWDM. 5. Show bollard detail and spacing per Dwg. No. 5-013 and Section 5.08 of KCRS. 6. Provide gravel access road to the inlet and control structure of the vault per SWDM 6.4.2.2. Sheet L1.01 1. Add KCRS Dwg. 5-009 street tree standards on plan. 5 Sheet C7.01 and C7.02 Pending review form KCDOT. Tree Retention Plan- 1 have completed preliminary review of the Significant Tree Retention Plan for the above referenced plat and have the following comments: 1. The applicant needs to submit a bond quantity worksheet (see attached). 2. All critical areas as defined by KCC 21 A.24 shall be designated on the plan. SigTreeExPlantBond .doc (56 KB)... R SIGNIFICANT TREE BOND QUANTITY WORKSHEET (Planting & Existing Trees) (Complete and return electronically) Date: 11108/07 Project Name: Talbot Ridge DDES Project Number: L07SR02 tt. g" V I Soil Preparation Topsoil $25/cy 4 $100 Mulch (2 inch depth X 36" round) $4/sy 23 $92 Fertilizer $6.67/cy 1 $6.67 Removal of invasive species - - Irrigation $0.80/sf 2. Plant Materials Deciduous Trees (Nursery Stock) Caliper: 3" $171 Evergreen Trees (Nursery Stock) Caliper: 3" $113 23 $2,599 Other Ground cover (includes labor) $4 - - 3. Labor& Equipment Costs Labor: (planting) $35/tree 23 $805 *Equipment: 4. Tree Protection Measures High Visibility Fencing Tree Stakes $2.65 69 $182.85 5. Monitoring Costs 3 years monitoring with reports - - - Included in LUIS inspection fees *Existing Significant Tree Values Ether: I Other: SUBTOTAL 30% CONTINGENCY & MOBILIZATION TOTAL PERFORMANCE BOND AMOUNT First $2500.00 shall be cash Quantity Calculations completed by: Approved by Site Development Specialist: $3,785.52 $1,135.96 $4,921.48 Josh Beard, L.A. (Core Design, Inc) * Use Tree Value for lumber mill prices at minimum SIGNIFICANT TREE RETENTION PLAN BOND INFORMATION_ (Planting & Existing Trees) This Significant Tree Retention performance and maintenance bond (for replanting and existing significant trees) is to ensure that significant tree replacements are planted and survive. It is also to ensure that the significant trees to be retained are saved in a healthy state and replaced as approved by the approved significant tree retention plan or DDES approved (documented) revisions to that plan. The planting portion of the bond is for a period of three (3) years monitoring from the date of tree planting installation acceptance in writing by DDES or until the approved Significant Tree Retention Plan has been successfully complied with. The existing bond amount can be released upon successful retention of the significant trees to be retained after the construction has been completed. At the final inspection for Significant Tree Retention by the DDES Land Use Inspection Unit (LUIS), the general site bond may be released if the site is in compliance with the DDES approved Engineering Site and Construction Plan and the Significant Tree Retention Plan. This Significant Tree Retention (Planting) portion of the performance and maintenance bond remains in affect for the three (3) year monitoring period even though LUIS has completed final construction inspection. The Significant Tree Retention Plan (Planting) monitoring and inspection responsibility will then be charged to DDES Site Development Services. If the project is not in compliance and there are dead planted and/or existing significant trees or other deficiencies not approved/documented from the approved Significant Tree Retention Plan at the time of LUIS final inspection, the general bond will be held until the deficiencies are corrected by the bond holder/permittee and monitoring responsibility transferred to Site Development Services. The permitteeldeveloper is responsible to post the bond with DDES (Financial Guarantee Section) prior to the LUIS pre -construction meeting and prior to starting any site work/disturbance. A private agreement may be necessary between the plat permitteeldeveloper, the future builder and the future landowner to ensure continued access for DDES inspections to the lots for the three (3) years monitoring or until the approved Significant Tree Plan has been complied with. This may require legal representation and is the sole responsibility of the plat permitteeldeveloper to secure this agreement. A copy of this agreement shall be submitted to DDES Site Development Services. The future builder/landowner on the referenced lots that include significant trees (existing or planted) shall not remove or damage these trees in any way without prior approval (a permit may be required) from DDES — Site Development Services. It shall be the responsibility of the bond holder to request bond release from DDES. If at the end of the three (3) year monitoring period (or as extended) the Significant Tree Retention Plan has not been complied with the bond may be forfeit to King County. It is the responsibility of the bond holder to perform monitoring and maintenance of the plantings as stated on the DDES Significant Tree Retention Plan. Status reports on planting success shall be submitted to DDES Site Development Services a minimum of once per year. Submittal of this bond by the permittee/designee and acceptance by DDES constitutes acceptance of the above stated conditions. King County Department of Development and Environmental Services 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 206-296-6600 TTY 206-296-7217 PROJECT NAME: Talbot Ridge Estates Rec. Space) DDES PROJECT #: L07SR02 ADDRESS: 19200 Blk 102nd Avenue SE PREPARED BY: Web date: 11/16/2005 LANDSCAPE BOND QUANTITY WORKSHEET FORM For alternate formats, call 206-296-6600. Core Design, Inc, Josh Beard, RLA PHONE: 425.885.7877 Bonds are based upon required landscaping only and will be posted for performance andlor maintenance. Required landscaping includes perimeter landscaping, surface parking area landscaping, (KCC 21A.16) and any landscaping required by SEPA environmental review. The maintenance period is for the life of the project, however, after posting for maintenance, the performance bond will be reduced to 30% ($1,000.00 minimum) and be held for a two year period. Upon re -inspection of the site the bond will be released if the site has been properly maintained (21A.16.180). A landscape maintenance inspection deposit is required priorto permit issuance to cover the costs of the 2-year maintenance Inspection. Landscape inspections are billed at the current hourly rate once the initial deposit is exhausted. If the project has not been maintained and there are dead trees, shrubs, ground cover, or other deficiencies noted in the required landscaping, the bond will be held until the deficiencies are corrected. UNIT PRICE UNIT TYPE QUANTITY PRICE SOD LAWN AREAS $500.00 MSF (1000 SQ. FT) 2.2 1,100 HYDROSEEDING $50.00 MSF (1000 SQ. FT) 8.4 420 SOIL PREPARATION A. TOPSOIL (6 INCHES DEEP) $25.00 CY (CUBIC YARD) 135 3,375 B. MULCH (2 INCHES DEEP) $4.00 SY (SQUARE YARD) 368 1,472 C. PEAT MOSS (TWO INCHES DEEP) $2.30 SY (SQUARE YARD) D. COMPOST (3 1NCHE5 DEEP & TILLING $26.00 SY (SQUARE YARD) E. FERTILIZER $6.67 CY (CUBIC YARD) 2 13.34 qw PLANT MATERIALS A. DECIDUOUS TREES 1.75 - 2.00" CALIPER (minimum height 10') PERIMETER & PARKING AREAS $250,00 EACH COST & LABOR 33 8,250 1.5 -1.75" CALIPER INTEMOR LANDSCARNG OR OTHER REQUIRED LmOWAPING $225,00 EACH COST & LABOR B. EVERGREEN TREES FIVE (5) FEET OR ABOVE $150.00 EACH COST & LABOR 37 5,550 C. SHRUB$ $35.00 EACH COST & LABOR 150 5,250 D. GROUND COVER $4.00 EACH COST & LABOR - _ SUB TOTAL BOND AMOUNT BOND AMOUNT SUB TOTAL: $ 25,430. 04120 LandscapeBond Quantity recspace.docb-wks-landscapebq.pdf 11/1612005 Page 1 of 2 UNIT PRICE UNIT TYPE QUANTITY PRICE ..... -- ----------- ------ MISCELLANEOUS TREE STAKES $2.65 EACH PER STAKE & LABOR 70 185.50 FENCING: LINEAR FOOT SOLID WOOD CEDAR $28.50 INCLUDES LABOR 25 712.50 BERMING $17.50 LINEAR FOOT INCLUDES LABOR IRRIGATION 800 SQUARE FOOT 4,860 3,888 RELOCATING TREES ON SITE 36" BALL $260.00 EACH 60" BALL $920.00 EACH RELOCATING SHRUBS ON SITE 12" BALL $26.00 EACH 24" BALL $33-00 EACH ADDITIONAL ITEMS: Onsite recreation facilities 1 $14,480 SUB TOTAL BOND AMOUNT BOND SUB TOTAL: $ 44,696 Add 30% of the Bond Sub -Total for Contingency in accordance with Financial Guarantee Ordinance 120220, Section 13. 30 % CONTINGENCY: $ 13,408.80 TOTAL BOND PRICE TOTAL BOND PRICE: $ 58,104.80 Revised LBQW 1111312002 Check out the DDES Web site at www.metrokc.govlddes 04120 Landscape BondQuantity reespaoe.doeb-wks-landscapebq.pdf 11116/2005 Page 2 of 2 CONDITIONS OF PERMITIAPPROVAL Activity Number: B07L1178 Type: NEWSRES Date: 8-1-07 WETLANDS/AQUATIC AREA CONDITIONS OF PERMIT/APPROVAL ***BUILDING INSPECTOR: PRE -CONSTRUCTION CONFERENCE REQUIRED. CONTACT BETH VINING, KING COUNTY SENIOR ECOLOGIST IN CRITICAL AREAS SECTION. 296-7291 ***BUILDING INSPECTOR: PLEASE DO NOT FINAL THIS PERMIT UNTIL ALL OF THE SPECIAL CONDITIONS HAVE BEEN MET. PLEASE CONTACT BETH VINING, KING COUNTY SENIOR ECOLOGIST IN CRITICAL AREAS SECTION, AT (206) 296- 7291. ***** THE 40-FT BUFFERS OF TWO CATEGORY IV WETLANDS HAVE BEEN ADJUSTED WITH BUFFER -WIDTH AVERAGING AS SHOWN ON THE APPROVED SITE PLAN. ONE CATEGORY IV WETLAND 40-FT BUFFER TO REMAIN AS IS. NATIVE VEGETATION IS TO BE MAINTAINED IN ALL BUFFERS AND ADJUSTED BUFFERS OF FROM EACH CATEGORY IV WETLAND. A I5-FOOT BUILDING SET BACK LINE (BSBL) IS REQUIRED FOR ALL STRUCTURES BEYOND THE BUFFER'S EDGE. PRIOR TO COMMENCING CONSTRUCTION ACTIVITIES, THE APPLICANT SHALL MARK THE BUFFER'S EDGE OF ALL WETLANDS AND CLEARING LIMITS IN A HIGHLY VISIBLE MANNER. TEMPORARY EROSION AND SEDIMENT CONTROL (SILT FENCE) SHALL BE INSTALLED ALONG THE PERIMETER OF CONSTRUCTION AREAS AS SHOWN ON THE APPROVED SITE PLAN. PRIOR TO A CERTIFICATE OF OCCUPANCY TE ADJUSTED BUFFERS SHALL BE IDENTIFIED WITH A WILDLIFE PASSABLE FENCE AND SENSITIVE AREA SIGNS (AVAILABLE AT THE PERMIT CENTER) AS SHOWN ON THE APPROVED SITE PLAN. THE WESTERN MOST CATEGORY IV WETLAND 40-FT BUFFER SHALL BE IDENTIFIED USING A SENSITIVE AREA SIGNS INSTALLED ON 4"X4" POST. ********SPECIAL CONDITIONS******* PRE -CONSTRUCTION CONFERENCE IS REQUIRED. THE APPLICANT AND CONTRACTOR MUST ATTEND. CALL BUILDING INSPECTION SERVICES AT 1-888-5-7728 TO SCHEDULE. n King County Department of Development and Environmental Services 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 206-296-6600 TTY 206-296-7217 PROJECT NAME: Talbot Ridge Estates Street Trees DDES PROJECT #. L07SR02 ADDRESS: 19200 Bilk 102nd Avenue SE PREPARED BY: Web date: 11116/2005 LANDSCAPE BOND QUANTITY WORKSHEET FORM For alternate formats, call 206-296-6600. Core Design, Inc. (Josh Beard, RLA) PHONE: 425.885.7877 Bonds are based upon required landscaping only and will be posted for performance and/or maintenance. Required landscaping includes perimeter landscaping, surface parking area landscaping, (KCC 21A.16) and any landscaping required by SEPA environmental review. The maintenance period is for the life of the project, however, after posting for maintenance, the performance bond will be reduced to 30% ($1,000.00 minimum) and be held for a two year period. Upon re -inspection of the site the bond will be released if the site has been properly maintained (21A.16.180). A landscape maintenance inspection deposit is required prior to permit issuance to cover the costs of the 2-year maintenance inspection. Landscape inspections are billed at the current hourly rate once the initial deposit is exhausted. If the project has not been maintained and there are dead trees, shrubs, ground cover, or other deficiencies noted in the required landscaping, the bond will be held until the deficiencies are corrected. UNIT PRICE UNIT TYPE QUANTITY PRICE SOD LAWN AREAS $500.00 MS (1000 SQ. FT) _ - HYDROSEEDING $50.00 MSF (1000 SQ. FT) - wi SOIL PREPARATION A. TOPSOIL (6 INCHES DEEP) $25.00 CY (CUBIC YARD) 53 1325 B. MULCH (2 INCHES DEEP) $4.00 SY (SQUARE YARD) 317 1268 C. PEAT MOSS (TWO INCHES DEEP) $2.30 SY (SQUARE YARD) - - D. COMPOST (3 INCHES DEEP & TILLING $26.00 SY (SQUARE YARD) _ - E. FERTILIZER $6.67 CY (CUBIC YARD) 1 6.67 �-...€:5 .ec:: m...-.-o... .< �..^::. Fes- 't ';. «.<,,m ;:: c.�.:.;....,.°•, ,.• ,E R€, n. ,<..... m.:.:.... ............•.. .ez€'ef .:..... . PLANT MATERIALS A. DECIDUOUS TREES 1.75 - 2.00" CALIPER (minimum height 10') PERIMETER & PARKING AREAS $250.00 EACH COST & LABOR 33 8,250 1.5 -1.75" CALIPER INTERIOR LANDSCAPING OR OTHER REOURED LANDSCAPING $225.00 EACH COST & LABOR - — B. EVERGREEN TREES FIVE (5) FEET OR ABOVE $150.00 EACH COST & LABOR C. SHRUBS $35,00 EACH COST & LABOR - - D. GROUND COVER $4.00 EACH COST & LABOR 114 456 SUB TOTAL BOND AMOUNT BOND AMOUNT SUB TOTAL: $ 11t 305.67 04120 LandscapeBondQuantitystreettrees.doc b-wks-landscapebq.pdf 11/16/2005 UNIT PRICE UNIT TYPE QUANTITY PRICE MISCELLANEOUS TREE STAKES $2.65 EACH PER STAKE & LABOR 99 262.35 FENCING: LINEAR FOOT SOLID WOOD CEDAR $28.50 INCLUDES LABOR - - BERMING $17.50 LINEAR FOOT INCLUDES LABOR - - IRRIGATION 80¢ SQUARE FOOT 300 240 RELOCATING TREES ON SITE 36" BALL $260,00 EACH _ 60" BALL $920.00 EACH - RELOCATING SHRUBS ON SITE 12" BALL $26.00 EACH _ - 24" BALL $33.00 EACH ADDITIONAL ITEMS: Onsite recreation facilities - - SUB TOTAL BOND AMOUNT BOND SUB TOTAL: $ 11,808.02 Add 30% of the Bond Sulu -Total for Contingency in accordance with Financial Guarantee Ordinance 120220, Section 13. 30 % CONTINGENCY: $ 3,542.40 TOTAL BOND PRICE TOTAL BOND PRICE: $ 15,350.42 Revised LBQW 11/1312002 Check out the DDES Web site at.www.metrokc._qov1ddes 04120 LandscapeBondQuantitystreettrees.doc b-wks-landscapebq.pdf 11/16/2005 King Gaunty Department of Development and Environmental Services 900 Oakesdale Avenue Southwest Renton, WA 98057-5212 206-296-6600 TTY 206-296-7217 www.metrokc.gov DATE: 3/7/2008 Permit Approval Conditions Document This plan reviewed to 2003 International codes updated to the State of Washington and King County Codes Structural Plan Review Tracking Number: L07SR012 Location: Talbot Ridge Estates Parcel #052205-9045 Storm Water Detention Vault The following conditions apply to the above referenced permit: 0001 GENERAL This correction sheet is an abridged version of code requirements and is a review aid only. It shall not be used in lieu of the International Building Code, International Mechanical Code, International Fire Code, or any King County regulation or state law. Please note that there are quite a few differences between the International Codes and the Uniform codes which King County previously adopted. For continued code compliance, carefully review the new provisions. Corrections noted below are part of the approved plans and shall remain attached to them at all times. The approval of plans and specifications does not permit the violation of any section of the International Building Code, International Mechanical Code, International Fire Code, or any King County regulation or state law. Corrections as indicated below, along with the unchanged information shown on the drawings, must be complied with. In addition, since this correction sheet is a review aid, it shall not be used in lieu of the above mentioned codes, regulations, and laws. Therefore, code compliance with all noted applicable code sections on this correction sheet, as well as other applicable code sections not specifically noted, shall be required. The approved plans shall not be changed, modified, or altered without authorization from the building official. The approved plans are required to be on the job site. Section 106.3.1 International Building Code 0348 SPECIAL INSPECTIONS A. Approval of Special Inspection Service shall be obtained from the Land Use Services Division, Site Development Inspection Unit, prior to construction. Section 106.3.4.3 I.B.C. as amended by King County Code B. Submit field inspection reports, test Iab reports and final reports to the Land Use Services Division, Site Development Inspection Unit, in compliance with Section 106.3.4.3 I.B.C. as amended by King County Code C. Provide the following special inspections (to comply with Section 1709, I.B.C.): 2003 IBC permit condition items Last saved by Hou-Ching Chow 03/07/2008 Page 1 of 2 1) Concrete work. 2) Concrete reinforcing steel placing. 3) Application of grouting at all concrete panel joints. 4) Anchor bolts installation into concrete. 0350 SPECIAL INSPECTIONS Provide special inspection by Geotechnical Engineer of Record for compliance with soil report recommendations. Submit field inspection reports, test lab reports and final reports to the Land Use Services Division, Site Development Inspection Unit, in compliance with Section 1704, I.B.C. The following items shall have special inspection: 1) Excavation and foundation subgrade preparation; and soil bearing load capacity confirmation 2) Wall lateral load design soil parameters confirmation. 3) Backfill soil materials selection and compaction. 4) Drainage systems installation behind walls. 0357 SPECIAL INSPECTIONS ---COMPACTED FILL MATERIAL Any fill emplaced under footings, slab, or other foundation systems must be certified by a special inspection as having been compacted to at least 95% of ASTM D-1557. 0366 SHOP DRAWINGS Engineer of record shall review and approve all shop drawings. An approved copy shall be submitted to the Land Use Services Division, Site Development Inspection Unit. 1) Concrete nix designs 2) Reinforcing steel. 3) Precast Prestressed concrete hollow core panels, design and reinforcing details. 4) Structural steel and grating. 2003 IBC permit condition items Last saved by Hou-Ching Chow 03/07/2008 Page 2 of 2 Project Information Complete all information on page 1, only site address and permit number on additional pages. l� Site Address !Lot No.: 1952 52 ✓' .91 T Permit Type: Permit Number: 4775R491 Permit Holder:W #iF 0W-2 Phone: MailingAddress: 3D1 %ifla Contact Person: _li% %r�R�►� Phone: A Plan Prepared By: 60M P"/" C%14*9 r1 � Attachments Attach the following to this plan: • Scale site plan drawings that include areas to be treated with Soil Treatment Options 1, 2, 3, 4a and/or 4b • Completed Compost and Topsoil Calculation Worksheet or printout of online Compost and Topsoil Caiculacur results. These calculations will be verified in the l7DES permit office, • Original compost andior topsoil test results reports demonstrating that products contain adequate organic matter (for soil treatment options 2, 3 and/or 4b) o Topsoil should contain 30-40% of compost by volume, which is equivalent to 8.13%soil organic matter). o Compost should contain 40 - 60% organic matter. Note: Retain original delivery tickets for compost and/or topsoil products for verification purposes - Soil Treatment Options for Areas Identified on Site Plan 5oiI treatment options available: • Option 1 - Leave native soil undisturbed, and protect from compaction during construction. • Option 2 - Amend existing soil in place. • Option 3 - Import topsoil mix with 8-13%soil organic matter content, • Option 4a - For native soil: stockpile site duff and topsoil, and reapply after grading and construction. • Option 4b - For disturbed soil: stockpile site soil, reapply, and amend in place. FOR DDES USE ONLY Plan Approval Record Date: Reviewer: Revisions Required: Approved: Area A (refer to lettered areas mapped on site plan) Square footage: �_L1V Selected soil treatment ption: Option 1 Option 2 J0ption3 JOption4a FJOption4b If using option 2 or 4b, select type of amendment rate: Pre -approved (2.5") Custom (with %Target Soil Organic Matter) Area —__9 (refer to lettered areas mapped on site plan) Squarefootage: Selected soil treatment o tion: Option 1 LlOption 2 LJOption 3 Xption 4a LJOption 4b If using option 2 or 4b, select type of amendment rate: []Pre -approved (2.5") ]Custom (with _%Target Soil Organic Matter) Area (refer to lettered areas mapped on site plan) 5quarefootage: Selected soil treatment option: Option 1 Option 2 J0ption3 LJOption4a Option 4b If using option 2 or 4b, select type of amendment rate: Pre -approved (2.5") Custom (with %Target Soil Organic Matter) Use additional Soil Management Plan forms for additional areas, if necessary. Record the compost and/or topsoil products to be used Compost Product #1: Test Results: %organic matter content Quantity: cubic yards Supplier: Product #2: Test Results: organic matter content Quantity: cubic yards Supplier: Topsoil Total cubic yards of compost Product #3: Test Results: %organic matter content Quantity: cubic yards Supplier: Product #4: Test Results: %organic matter content Quantity: cubic yards Supplier: Total cubic yards of topsoil Page of Date: Reviewer: Approved: Revisions Required: Compost and Topsoil Calculation Worksheet for the Pre -approved Amendment Rate NOTE. For Options 2 cod4b, use this worksheerifyou plan to use the pre -approved compost amendment rate of2.5 inches. This worksheet should not be used if a custom compost amendment rate is selected for Options 2 and/or 4b. Instead, use the online Compost and Topsoil Calculatorat ^ .^ tiv.i�etr kc.yc,'r�nri�,'s,vdlcompost_calcuiator.htm. Option 1 Leave native soil undisturbed, and protect from compaction during construction. u Enter lettered areas from site plan where this option will be used: b:. . u! E-s. -- -- I,AND USE SERVICES No calculations for compost or topsoil are necessary for this option, oIVISIC;i"\i Option 2 Amend existing soil in -place (2.5 inch layer of compost). Enter lettered areas from site plan where this option will be used: Enter combinedsquare footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) x 8 Multiply combinedsquare footage by 8 and enter product in box A = Cubic Yards AMOUNT OF COMPOST NEEDED FOR THESE AREAS Option 3 Import topsoil mix with 8 -13%soil organic matter (8 inch depth of topsoil). Enter lettered areas from site plan where this option will be used: Enter combinedsquare footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter.5) x 25 Multiply combinedsquare footage by 25 and enter in box B — • - Cubic Yards AMOUNT OF IMPORTED TOPSOIL NEEDED FOR THESE AREAS Option 4a Native Soil - stockpile site duff and topsoil and reapply after grading and construction. Enter lettered areas from site plan where this option will be used: Enter combinedsquare footage of lettered areas in thousands '�" a (example: for 4,525 sq ft, enter 4.525; for 500 sq ftr enter .5) x 25 Multiply combined squarefootage by 25 and enter in box C 15 0 Cubic Yards AMOUNTOF SITE TOPSOILTO BE STOCKPILED AND REAPPLIED IN THESE AREAS Achieving the Post -construction Soi! Standard King County i Department of oeveiowent & Ervirormentai Services SIGNIFICANT TREE and SOILS AMENDMENT BOND QUANTITY WORKSHEET (Planting & Existing Trees and Recreation Space) (complete and attach to Tree Plan) r� Date: 6n o/o8 ! � ` I `11 � Project Name: Talbot Ridge Estates DDES Project Number: L07SR02 JUN 0 Ages s; Price Each Quantity Total Mce> K1 ent s 1. Soil Preparation Topsoil to 8" depth in disturbed areas Mulch/compost 2.5" depth rototil led into soil Fertilizer for plantings $6.67/cy 1 $6.67 Removal ol-invasive species Irrigation (watering during dry months) 2. Plant Materials Deciduous Trees (Nursery Stock) Caliper: 3" cal $175 4 $700 Evergreen Trees (Nursery Stock) Caliper: 2" cal / 6' ht $1 15 7 $805 Other: 3. Labor & Equipment Costs Labor: (planting and soil amending) $35 11 $385 *Equipment: 4. Tree Protection Measures High Visibility Fencing Tree Stakes $2.65 33 $87.45 S. Monitoring Costs 3 years monitoring with reports Included in LUIS insnection fees *Existing Significant Tree Values $ 1,000.00 18 $18,000 Other: Other: SUBTOTAL $19,954.12 30% CONTINGENCV & MOBILIZATION $5.986.24 TOTAL PERFORMANCE BOND AMOUNT $25940.36 First $2500.00 shall be cash Quantity Calculations completed by: Approved by Site Development Specialist: * Default Tree Value SIGNIFICANT TREE RETENTION and SOIL AMENDMENT PLAN BOND INFORMATION (Planting & Existing Trees) This Significant Tree Retention and Soil Amendment performance and maintenance bond (for replanting and existing significant trees and for compliance with the Soil Amendment Plan) is to ensure that the work is performed as approved and that the significant tree replacements are planted and survive. It is also to ensure that the significant trees to be retained are in a healthy state and replaced as approved by the approved significant tree retention plan or DDES, approved (documented) revisions to that plan. The planting portion of the bond is for a period of three (3) years monitoring from the date of tree planting installation acceptance in writing by DDES or until the approved Significant Tree Retention Plan has been successfully complied with (this is normally when the street tree bond is released). The portion of the bond for soils amendments can be released at final inspection approval by the LUIS Inspector for plat recording if the work has been accomplished per the approved plan. This Significant Tree Retention (Planting) portion of the performance and maintenance bond remains in affect for three (3) years with DDES monitoring or at the time of final street tree approval and bond release, whichever comes first. If the Tree Retention Plan is not in compliance at the end of the street tree monitoring period LUIS can forward monitoring responsibility to DDES Site Development Services. DDES Site Development Services will assign an inspection/monitoring tracking number and bill the permittee the hourly rate in effect at that time as established by the King County Council Fee Ordinance. The permittee/developer is responsible to post the Significant Tree Retention and Planting Bond and Soils Amendment Plan with DDES (Financial Guarantee Section) prior to the LUIS pre -construction meeting and prior to starting any site work/disturbance. A private agreement may be necessary between the plat permittee/developer, the future builder and the future landowner to ensure continued access for DDES inspections to the lots for the three (3) years monitoring or until the approved Significant Tree Plan has been complied with. This may require legal documentation as requested by DDES and is the sole responsibility of the plat permittee/developer to secure this agreement. A copy of this agreement shall be submitted to DDES Site Development Services and the LUIS Inspector. The future builder/landowner on the referenced lots that include significant trees (existing or planted) shall not remove or damage these trees in any way without prior approval (a permit may be required) from DDES — Site Development Services. It shall be the responsibility of the bond holder to request bond release from DDES. If at the end of the three (3) year monitoring period (or as extended) the Significant Tree Retention Plan has not been complied with the bond may be forfeit to King County. It is the responsibility of the bond holder to perform monitoring and maintenance of the plantings as stated on the DDES Significant Tree Retention Plan or as legally assigned to others as stated above, or until the 3 year final monitoring inspection has been completed by DDES. Status reports on planting success shall be submitted to DDES Site Development Services a minimum of once per year. If at the end of the three year monitoring period the reports have not been submitted or the work not performed per the approved plan the bond may be forfeit as stated above. Submittal of this bond by the permittee/designee and acceptance by DDES constitutes acceptance of the above stated conditions. elmont Homes, Inc. PO Box 2401 Kirkland WA, 98083 May 7, 2008' Jim Sanders, PE Managing Engineer - Supervisor u, ra King County DDES 900 Oakesdale Ave SW r n Renton, WA 98057 RE: TALBOT RIDGE ESTATES — L05P0007 REQUEST FOR EARLY START PERMIT — L08SR023 Dear Mr. Sanders: We respectfully request approval of an `early start' permit for Talbot Ridge Estates. This project which is in the final stages of approval has essentially been put on hold by DOT reviewers. The project includes an offsite road realignment of the former County Road, SE 192Rd Street. DOT Traffic is now (11 [h hour, they are into their third review) apparently questioning a County Road Engineer (CRE) approved road variance issued for this project on September 21, 2006. 1 have been advised that a meeting between traffic and CRE is set for June 2, 2008. The impact that decisions reached at this meeting will have on project design and construction schedule is unknown. Since the delayed approval is limited to the offsite channelization plan, we believe it is appropriate to proceed with onsite work immediately. Any assistance you can offer your colleagues at DOT to help resolve their differences would be appreciated. If you have any questions, please call me at 206 714-7161 or email me at clifUa belmonthomeswa.com. Thank you for your consideration. i , ms, PE ,er of Engineering CC: John O'Neil, JWO, LLC Rob Stevens, PE Core Design Wylie Wong, DDES r �� /�J - -7 r� - -, ___- ...w.._� �. - ---..��.__.d-___. �=�_. Core Design, Inc. CORE 14711 N. E. 29th Place, Suite i 01 DESIGN Bellevue, Washington 98007 425.885.7877 Fox425.885.7963 www.coredesign;nc.com TECHNICAL INFORMATION REPORT (T.I.R.) FOR TALBOT RIDGE ESTATES KING COUNTY, WASHINGTON � �.pi�.rjyx ►?�t�t DD I'11i\/ � J LL1l:l7 K.C. L)0 LAND USE SERViC::1 DIVISION Prepared by: Gina R. Brooks, P.E. James A. Morin, P.E. Date: March, 2007 Revised: November, 2007 Core No.: 04120 TI-2--1 0 8 ENGINEERING - PLANNING - SURVEYING KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 3F TYPE OF PERMIT APPLICATION Landuse Services diviso Short Subd. / UPD ❑ Building Services M/F l Commerical / SFR Clearing and Grading Right -of -Way Use ❑ Other Site Address `Part 4.` OTHER REVEEWSrAND PERfU11T5 ❑ DFW HPA ❑ Shoreline ❑ COE 404 Vanagement ❑ DOE Dam SafetyockeryNault/ Structural ElFEMA Floadplain ❑ ESA Section 7 ❑ COE Wetlands ❑ Other Part 5 PLAN AND REPORT IIVFDRMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Parge / Targeted / Type (circle one): Full I Modified I (circle): Site mall Site Date (include revision f1jaLd A,D020��% Date (include revision M&Y U, oZ. 00-7 dates): dates): Date of Final. Date of Final: Type (circle one): Standard / Complex / Preapplication 1 Experimental / Blanket Description: (include conditions in TIR Section 2) Date of Approval: _`��1 ��j a) 9 /al (p SE 2005 Surface Water Design Manual 111105 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Fran $ SITE COMMUNITY. AND DRAINAGE.BASIN Community Plan: Special District Overlays: Drainage Basin: j!)l 0.C.iC1V.@ Stormwater Requirements: Part.10 SOILS 4 4 -1 Soil Type Slopes Erosion Potential +l � 2�u�cxs� Cp�C�� Lo -15�a ►rntac�-�rar`�. ❑ High Groundwater Table (within 5 feet) ❑ Sole Source Aquifer ❑ Other ❑ Seeps/Springs ❑ Additional Sheets Attached 2005 Surface Water Design Manual 111105 2 ICING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL. TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PArt 1 =TIR F;IJM' EARY:SHPF.T fnrnv�riPnneiIFZSuirirharv.,§ eetnerThresholdDrscha'rae-Meal Threshold Discharge Area: name or description) Core Requirements (all 8 apply) Discharge at Natural Location Offsite Analysis Flow Control (inciJacility summary sheet Conveyance System Erosion and Sediment Control ntenance and Operation Financial Guarantees and Liability Water Quality (include facility summary sheet) Number oLUatural C Level: 1 2 / 3 Small Site BMMi )rZV A-0 r Locations: dated:-7 Spill containment located at: ESC Site Supervisor: n Contact Phone: After Hours Phone: Responsibifity: Private Public It Private, Maintenance 1-paRegul Provided: Yes / No Type: Basic / Sens. Lake 1 or Exemp ion No. Landscape Manaqement Plan: Y Ali A �1 i0o Number �-- U r cies 13n red: Yes / No Enhanced Basicm 1 Bog es / No S ecial Requirements as applicable) Area Specific Drainage Type: CDA / SDO / MDP / BP 1 LMP I Shared Fac. None Requirements Name: Flood plain/Fioodway Delineation Type: Major I Minor 1 Exemption None 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (comm./industrial landuse) Describe any structural controls: 2005 Surface Water Design Manual 3 111105 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High -use Site: Yes ILNo Treatment BMP: Maintenance Agreement: Yes / No with whom? I Other Drainage Structures I EMENTS 1. ."; - TaIf RO.810.'N P, MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Clearing Limits AFTER CONSTRUCTION Stabilize Exposed Surfaces Cover Measures 0Remove and Restore Temporary ESC Facilities Perimeter Protection Clean and Remove All Silt and Debris Ensure Traffic Area Stabilization Operation of Permanent Facilities LJ Flag Limits of SAO and open space Sediment Retention preservation areas Surface Water Control Ll Other Dust Control Construction Sequence park'-14-'-,$TORMWATER-FACILITY,,,.DES.CRIP-TILN _$.J14�fe.- -]h . d Ude.F6&.iI15ijffir.n_;and .. Flow Control Type/Description Water Quality Lion Type/Descrip n 14 Detention 0 Infiltration ❑ Regional Facility ❑ Shared Facility L1 Small Site BMPs 0 Other \ool+ El BioNtration A Wetpooi El Media Filtration LJ Oil Control El Spill Control 0 Small Site BIVIPs Ll Other V(aL)I+ 2005 Surface Water Design Manual 4 1/1 /05 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 . EASEMENTS/TRACTS Part.16 STRUCTURAL ANALYSIS ❑ Drainage Easement Cast in Place Vault ❑ Access Easement ❑ Retaining Wall ❑ Native Growth Protection Covenant JWRockery > 4' High 14 Tract ❑ Structural on Steep Slope ❑ Other ❑ Other ::'Part 1IT' SIGNATURE OF PROFESSIONAL ENGINEER-. I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. 0­7 Si nedlDafe 2005 Surface Water Design Manual 5 111105 TALBOT RIDGE ESTATES TABLE OF CONTENTS 1. Project Overview 2. Conditions and Requirements Summary 3. Off -Site Analysis 4. Flow Control and Water Quality Facility Analysis and Design 5. Conveyance System Analysis and Design 6. Special Reports and Studies 7. Other Permits 8. CSWPPP Analysis and Design 9. Bond Quantities, Facility Summaries, and Declaration of Covenant 10.Operations and Maintenance Manual 1. PROJECT OVERVIEW: The project site is located south of SE 192"d Street and west of 102❑d Avenue SE, just outside the City of Renton City Limits in unincorporated King County. Specifically the project is in the northwest quarter of Section 5, Township 22 N, Range 5 E. See attached vicinity map following this section. Also see the following "King County Aerial Map" for an overall view of the area. The King County tax parcel ID for this property is 0522059045. The site is bordered by SE 192" d Street and single family residences on the north, 102" d Avenue SE on the east, an existing single family residence to the south and the Plat of High Park Tracts to the west. The property is 4.36 acres in size and vacant. Ground cover is predominately forested except for pavement along the west boundary that is part of the road section for 102°d Avenue SE. The property generally slopes downward to the west with the western third of the property as steep as 4.1. No upstream drainage is received by the property. Existing sheetflow drainage is received by three existing single family lots adjacent to the west boundary of the subject property. See Downstream Analysis (Existing Course) in Section 3 of this Report for a description of the existing downstream system. The approved preliminary plat had a layout with 27 lots. This number of lots required a transfer of development rights (TDRs). It has since been decided to increase the lot size and reduce the lot number so TDRs are no longer required. Some of the lot numbers in the Hearing Examiner's Conditions no longer make sense unless the preliminary plat is referenced. The proposed project includes constructing 22 single-family residential lots with associated roadways and utilities. Access to the site will be via 102nd Avenue SE. Half - street improvements on 102nd Avenue SE along the property's east frontage, including minor pavement widening and installation of curb, gutter, and sidewalk, will be completed as part of the subject project as well as more extensive improvements along SE 192nd Street which will address existing inadequate stopping sight distance. Developed drainage will be conveyed to a proposed combination water quality/detention vault that will be located in the northwestern corner of the property. The vault will discharge to an existing ditch located just beyond the northwest corner of the property within the SE 192"d Street Right -of -Way. The existing ditch is located within a separate basin from the existing discharge location described above. See Downstream Analysis (Discharge Course) in Section 3 of this Report for a description of the proposed discharge downstream system. Discharge to the existing ditch has been approved via the 2005 KCSWDM Adjustment Request (File No. L05V0061). See copy of approved adjustment in Section 2 of this Report. As a requirement of the SWM Adjustment, a 10% volumetric factor of safety will be applied to the detention facility. Also, the site is subject to the Conservation (Level Two) Flow Control and Basic Water Quality requirements within the 2005 King County Surface Water Design Manual (2005 KCSWDM). a en ac o. 1 VICINITY MAP APPROXIMATE SCALE 1"=4000' 2. CONDITIONS AND REQUIREMENTS SUMMARY: Attached on the following pages are the Hearing Examiner's conditions along with the 2005 KCSWDM Adjustment Request (File No. L05V0061), Road Variance (File No. L05V0066), and letters from affected neighbors authorizing regrading of existing driveways adjacent to revised SE 192"d Street, 1. Compliance with all platting provisions of Title 19A of the King County Code. 2. All persons having an ownership interest in the subject property shall sign on the face of the final plat a dedication which includes the language set forth in King County Council Motion No. 5952. 3. The plat shall comply with the density requirements of the R-6-SO zone classification. All lots shall meet the minimum dimensional requirements of the R-6-SO zone classification or shall be as shown on the face of the approved preliminary plat, whichever is larger, except that minor revisions to the plat which do not result in substantial changes may be approved at the discretion of the Department of Development and Environmental Services. 4. The applicant shall provide the TDR certificate with the submittal of the engineering plans and the final plat. If the TDR certificate cannot be obtained, the applicant shall redesign the number of lots based upon the allowable density. This will result in the reconfiguration and loss of lots. 5. All construction and upgrading of public and private roads shall be done in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS). 6. The applicant shall obtain documentation by the King County Fire Protection Engineer certifying compliance with the fire flow standards of Chapter 17.08 of the King County Code. 7. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location of lots as shown on the approved preliminary plat. Preliminary review has identified the following conditions of approval which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual and applicable updates adopted by King County. DDES approval of the drainage and roadway plans is required prior to any construction. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review, shall be shown on the engineering plans. C. The following note shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings # on file with DDES and/or the King County Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for individual lot infiltration systems, the systems shall be constructed at the time of the building permit and shall comply with plans on file." d. The stormwater facilities for this site shall be designed to meet at a minimum the Conservation Flow Control and Basic Water Quality requirements in the 2005 King County Surface Water Design Manual (KCSWDM). A Surface Water Drainage Adjustment (L05VO061) is approved for this site. All conditions of approval for this adjustment shall be met prior to approval of the engineering plans. C. To implement the required Best Management Practices (BMP's) for treatment of storm water, the final engineering plans and technical information report (T1R) shall clearly demonstrate compliance with all applicable design standards. The requirements for best management practices are outlined in Chapter 5 of the 2005 KCSWDM. The design engineer shall address the applicable requirements on the final engineering plans and provide all necessary documents for implementation. The final recorded plat shall include all required covenants, easements, notes, and other details to implement the required BMP's for site development. 8. The applicant's geotechnical engineer shall provide recommendations for the design and construction of the road, onsite grading and compaction, drainage detention vault, and any required retaining walls. The geotechnical recommendations shall be included in the TIR and incorporated into the design with submittal of the engineering plans. 9. Special geotechnical construction inspection of the road improvements, onsite grading and compaction, drainage detention vault, and any required retaining walls is required to ensure compliance with the geotechnical recommendations. Daily inspection reports shall be submitted to the assigned Land Use Inspector during the construction phases of those facilities. A final construction report shall be submitted verifying compliance with the geotechnical recommendations. Notes requiring the above shall be shown on the engineering plans. 10. Geotechnical engineer review of the future home foundation construction is required. Notes to this effect shall be shown on the engineering plans and the final plat. 11. The proposed subdivision shall comply with the 1993 King County Road Standards (KCRS) including the following requirements: a. Road A shall be improved at a minimum to the urban subaccess street standard, with a cul-de-sac at the west end. If Road A is improved with only a 24-foot roadway width, then it shall be signed "No Parking" on both sides of the road. b. FRONTAGE: The frontage along 102" d Ave SE shall be improved at a minimum to the urban neighborhood collector street standard (west side). The design shall require compliance with Section 4.01(f) of the KCRS; asphalt overlay when widening. C. FRONTAGE: The frontage along SE 192"d Street shall be widened and lowered, as approved by DDES and in compliance with the conditions of approval for Road Variance LO5V0066. The frontage shall be widened to the urban neighborhood collector standard on the south side. The road lowering is required to improve the entering and stopping sight distance at the SE 192°d Street/102°d Ave SE intersection. Details of this improvement shall be shown on the engineering plans and routed to KCDOT for approval. d. The proposed private access tract and joint use driveways shall comply with Sections 2.09 and 3.01 of the KCRS, unless otherwise approved by DDES. These tracts shall be owned and maintained by the lot owners served. Notes to this effect shall be showed on the engineering plans and the final plat. e. Modifications to the above road conditions may be considered according to the variance provisions in Section 1.08 of the KCRS. 12. All utilities within proposed rights -of -way must be included within a franchise approved by the King County Council prior to final plat recording. 13. The applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The applicant has the option to either; (1) pay the MPS fee at final plat recording, or (2) pay the MPS fee at the time of building permit issuance. If the first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All fees required by King County Code 14.75, Mitigation Payment System (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building permit application. 14. Lots within this subdivision are subject to King County Code 21A.43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent (50%) of the impact fees due for the plat shall be assessed and collected immediately prior to recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shall be allocated evenly to the dwelling units in the plat and shall be collected prior to building permit issuance. 15. The planter islands (if any) within the cul-de-sacs shall be maintained by the abutting lot owners or homeowners association. This shall be stated on the face of the final plat. 16. Suitable recreation space shall be provided consistent with the requirements of KCC 21A.14.180 and KCC 2IA. 14.190 (i.e., sport court[s], children's play equipment, picnic table[s], benches, etc.). A detailed recreation space plan (i.e., area calculations, dimensions, landscape specifications, equipment specifications, etc.) shall be submitted for review and approval by DDES and King County Parks prior to or concurrent with the submittal of the engineering plan. This plan must not conflict with the Significant Tree Inventory & Mitigation Plan. b. A performance bond for recreation space improvements shall be posted prior to recording of the plat. 17. A homeowners' association or other workable organization shall be established to the satisfaction of DDES which provides for the ownership and continued maintenance of the recreation, open space and/or sensitive area tract(s). 18. Street trees shall be provided as follows (per KCRS 5.03 and KCC 2IA. 16.050): a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. C. If King County determines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right- of-way line. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the County has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. e. The species of trees shall be approved by DDES if located within the right-of- way, and shall not include poplar, cottonwood, soft maples, gum, any fruit -bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or storm sewers, or that is not compatible with overhead utility lines. f, The applicant shall submit a street tree plan and bond quantity sheet for review and approval by DDES prior to engineering plan approval. g. The applicant shall contact Metro Service Planning at 684-1622 to determine if SE 192nd Street and/or 102"d Avenue SE are on a bus route. If SE 192"d Street and/or 102"d Avenue SE are a bus route, the street tree plan shall also be reviewed by Metro. h. The street trees must be installed and inspected, or a performance bond posted prior to recording of the plat. If a performance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year. After one year, the maintenance bond may be released after DDES has completed a second inspection and determined that the trees have been kept healthy and thriving. i. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on the current County fees. 19. To implement SO-220 pursuant to former KCC 21A.38.230, a detailed tree retention plan shall be submitted with the engineering plans for the subject plat. The tree retention and engineering plans shall be consistent with the requirements of SO-220. No clearing of the site is permitted until the tree retention plan is approved by DDES. Flagging and temporary fencing of trees to be retained shall be provided, consistent with SO-220. The placement of impervious surfaces, fill material, excavation work, or the storage of construction materials is prohibited with the fenced areas around preserved trees, except as may be permitted under the provisions of SO-220. A note shall be placed on the final plat indicating that the trees shown to be retained on the tree retention plan shall be maintained by the future owners of the proposed lots, consistent with KCC 21A.38.230(B)(6). The tree retention plan shall be included as part of the final engineering plans for the subject plat. 20. In the event that any archaeological objects are uncovered on the site, the applicant shall comply with RCW Chapter 27.53, Archaeological Sites and Resources. Immediate notification and consultation with the State Office of Archaeology and Historical Preservation, King County Office of Cultural Resources and relevant tribes (including the Suquamish, Puyallup and Muckleshoot tribes) is required if discovered materials are prehistoric and a site is present. 21. All future residences constructed within this subdivision are required to be sprinkled NFPA 13D unless the requirement is removed by the King County Fire Marshal or his/her designee. The Fire Code requires all portions of the exterior walls of structures to be within 150 feet as a person would walk via an a roved route around the building) from a minimum 20-foot wide, unobstructed driving surface. To qualify for removal of the sprinkler requirement driving surfaces between curbs must be a minimum of 28 feet in width when parking is allowed on one side of the roadway, and at least 36 feet in width when parking is permitted on both sides. Additionally, minimum 20-foot wide driving surfaces must be provided on Tracts A and B, and the driveway serving Lot 11; or residences constructed on Lot 11, and Lots 16 through 19 and 23 through 26 will have to be sprinkled. King County Department of Development and Environmental Services 900 Oakesdale Avenue SW Renton, WA 98055-1219 November 17, 2005 Robert Wenzl Robert H. Stevens, P.E. Belmont Homes, Inc. Core Design, Inc. P.O. Box 2401 14711 NE 20 Place, # 101 Kirkland, WA 98083 Bellevue, WA 98007 RE: Talbot Ridge Subdivision 2005 KCSWDM Adiustment Request (File No. L05V0061) Dear Applicant and Engineer: The Land Use Services Division, Engineering Review Section, has completed review of the adjustment request for the Talbot Ridize subdivision. You are requesting approval for an adjustment from the 2005 King County Surface Water Design Manual (KCSWDM) Core Requirement No. 1, Section 1.2.1, Discharge at the Natural Location. Our review of the information and a site visit provides the following findings: 1. The proposed Talbot Ridge subdivision is located adjacent to the southwest corner of the intersection of SE 192nd Street and 102" d Avenue SE. The 27 Iot, 4.36 acre, proposed Talbot Ridge subdivision is filed under Land Use Services Division (LUSD) file number LOSP0007. 2. The Talbot Ridge subdivision is located in the Springbrook Creek tributary area, Black River subbasin of the Lower Green River basin. The site is subject to the Conservation (Level Two) flow control and Basic water quality requirements of the 2005 KCSWDM. The east -west oriented rectangular site slopes moderately from east to west. The western edge of the site contains slopes steep enough to prevent development. Sheetflow from the site then enters the backyards of the lots on the east side of 99,t' Place South, migrates through the lots and ends up on 991h Place South. The 99Ih Place South drainage system directs flows south and enters the Springbrook Park watershed area characterized by very steep slopes and designated landslide and erosion hazard areas. Flow continues west through the watershed area until passing west via culvert under Talbot Road South. Flow continues northwest through the Springbrook Trout Farris, a designated wetland area and then crosses north under South 55 Street (the City of Renton's designation for SE 192"d Street) and turns west to pass under Highway 167. By this time, the stream is designated salmonid. Very little upstream flow enters the site. Talbot Ridge/L05V0061 November 17, 2005 Page 2 of 3 4. The proposal is to collect most runoff from the project site and direct it to a single detention and water quality facility located near the northwest corner of the site just shy (east) of the steep slope area. The allowed release would then be conveyed to the western property line that abuts the right-of-way and outlet to an open ditch: Flow would then enter a catch basin on the south side of SE 192d Street and be diverted from its natural discharge location by crossing to the north side of the road. Drainage would continue west along the north side of SE 192nd Street. After crossing Talbot Road South, the diverted downstream path would realign with the original downstream path before reaching Highway 167. Nuisance flows to the abutting lots on the western property line would see sheetflow significantly reduced. There would be a reduction in flows through the landslide and erosion hazard areas of the Springbrook watershed. Frontage improvements are included in the conceptual drainage plan. 5. No decorative ponds or shallow wells have been identified that would be affected by the proposed diversion, 6. The Level One Drainage Analysis identified no restrictions or problems associated with the proposed discharge location. In fact, it is the natural discharge location that has experienced drainage complaints. Where flows enter the watershed area at the southern end of 99ffi Place South erosion has been reported. In addition, the downstream Trout Farm has experienced erosion problems from suspended sediments during new construction. The diverted path would help to reduce these occurrences. Based on these findings, we hereby approve this adjustment to allow the off -site diversion of runoff from the storrnwater facility draining to the north side of South 192n1 Street with the following conditions: 1. The release rates for the detention facility will be based on the tributary area being directed to the facility. 2. The volume for the detention facility will be based on all flows directed to the facility at full development under current zoning. The allowed release rate will be reduced by any undetained flows that would bypass the proposed subdivision drainage facilities. The detention volume shall be sized using the Conservation flow control standard in the 2005 KCSWDM, A 10 to 20 percent volumetric factor of safety must be applied to all storm events requiring detention. The design Technical Information Report shall state the factor of safety selected and the basis of that determination. 3. Water quality facilities must be sized based on the entire proposed subdivision draining to the facilities including any required frontage improvements. 4. All onsite or offsite drainage facilities must be located in a public right-of-way, recreation space tract with easement or storm drainage tract dedicated to King County. Talbot Ridge/L05V0061 November 17, 2005 Page 3 of 3 5. Additional storm drainage requirements identified by SEPA or the plat hearing review will apply to this project. The applicant retains all rights and privileges afforded in Section 1.4. If you have any further questions regarding this KCSWDM adjustment or the design requirements, please contact Mark Bergam at (206) 296-7270. Sincerely, James Sanders, P.E. Development Engineer Engineering Review Section Land Use Services Division Tim Chan, P.E. Supervising Engineer Site Engineering and Planning Section Building Services Division cc: Curt Crawford, P.E., Managing Engineer, Stormwater Services Section, KCDNR Bruce Whittaker, Engineer III, Engineering Review Section, LUSD Trisha Bull, Project/Program Manager 11, Current Planning Section, LUSD Marls Bergam, P.E., Engineer III, Engineering Review Section, LUSD Surface Water Design Manual Kimgty Requirements / Standards Departtacnt of llevetopment and EnviranmeMSer al vices 900 Oekcsdaio Aveu= Southwest Reataa,Washingt(m98055-1219 Adjustment* Request Project Name: DDES Project File No.: L05P0007 Talbot Ridge Estates DDES Engineer/Planner Name: Bruce Whitaker / Trishah Ba11 Project Address-. Design Engineer: Phone: 19200 102nd Avenue SE Robert Stevens -PE 425-885-7877 Appicant/Agent Phone: Signature., ,4,1i . Dow., Bel mmt 22!!es 205-714-71 b1 t SCE Sl Engineering Firm Name: M yd &V11 � Core Design, Inc. Aci Tess: C , Stafe, 2ip Code: Address. City, State, Tip Code: 14711 NE 29th P1. #101, Bellevue, WA, 98007 INSTRUCTIONS TO APPLICANTIDESIGN ENGINEER: Please be sure to include all plans (T.I.R , if available), sketches, photos and maps that may assist in complete review and consideration of this adjustment requasi. Faith to provide all pertinent Information may result In delayed processing or derdal of your request, Please submit two eornaki copies pf this request. spj$loatlon form. and aoellcable fee to the DDES Intake Counter, at 900 Oakesdaie Avenue Southwest, Renton, Washington 98055-1219. For additional information, phone Randall Parsons, P-E., at (200 295-7207. RRFBR To SECTION 1.4 IN CHAPTER 1 OF THE SURFACE WATER D993: N auLN1TAL FoR ADjUSTX3VT5 DESCRIPTION OF ADJUSTMENT REQUEST: ❑ Standard Zi Complex O lExperimental 0 Blanket 0 Pre-appiicabon APPLICABLE VERSION KCSWDM: ❑ 1990 (11195) " © 1998 (9198) 0 2005 * (Note: the term "variance replaced by "adjustment") APPLICABLE SECTION(S) OF STANDARDS: Core Requirement #1 rm JUSTIFICATION PER KCSWDM SECTION IA.2 ❑ See attachments listed below. AUTHORIZATION SIGNATURES: p Approval ❑ DNRWLRD Approval Signed: S Staff Recommendation Signed: Sea attached Memo Dated: Conditional Approval (see below) 1 r d ,A Date: ." 17- _0 613DES DI; - Lt u �/ " [ JD AUG 09 2005 K.C. D.D.E.S. 0 Denial (Experimental & Blanket variances only) Date: 1# "�' ^O Land Use Services Div., Engineering Review Supervisor. I DDES, Bldg. Serv. Div., Site Engineering & Planning I Signed: <l F99/ERS/SWW-AA7.d0c F96/ERS/SK*M-8.cpy22.d0C lx/17/99 cic LO 5 V 0 0" G I Talbot Ridge Estates - Adjustment Justification An adjustment is requested to Core Requirement #1 — Discharge at the Natural Location, Section 1.2.1 of the 1998 King County Surface Water Design Manual for the Talbot Ridge Estates project. Currently the site's stormwater sheet flows to the west property line to the rear yards of the adjacent lots which front onto 99t' Place S. The drainage then flows to the south through an existing storm drain system on 99c' Place S. Once to the south end of 99"' PIace S., the stormwater discharges through an SAO Landslide Hazard Area and then on to an SAO Erosion Hazard area. Drainage complaints 2003-0194 and 1998-0461 have been filed relating to slippage of the landslide hazard area at the south end of 99 h Place S. After the stream exits the SAO Erosion Hazard area, it joins with Springbrook Creek, crosses under Talbot Rd. and passes through the Gallagher property, a trout farm with a history of siltation due to neighboring developments. Drainage complaint 1998-0045 has been filed relating to silt entering the trout farm pond. The flow then discharges into an SAO Class 2 wetland. The flow exits the northwest edge wetland and flows north under S. 192"d St. and continues northwest. This point is approximately 0.6 miles from the project site. We have proposed a discharge location that will connect the discharge from the site into an existing storm drainage that runs west along S. 192" d St. The system crosses under Talbot Rd. S. and continues west until discharging into Springbrook Creek, converging on the discharge location stated above, approximately 0.6 miles frorn the project site. There are no SAO hazard areas or drainage complaints associated with this drainage route. The proposed discharge of stormwater into the system on S. 192nd St. fulfills all the criteria for granting an adjustment which are: 1 _ To produce a compensating and comparable result that is in the public interest, AND 2. To meet the objectives of safety, function, appearance, environmental protection and maintainability based on sound engineering judgement. For these reasons we request this adjustment to the discharge location. E5 E� }J Z U,v i 9� D K.C. D.D.E.S. 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' . ---.,. . sue- r.� .. '"i;�` l�!' �' ram' ( r: �� : �.a�c°irrC.w¢�•.' F{'! I+'y$ s r i i i�4'�'- 5 - .jt+.-- }..=_: -., `�. J r �• Eel, I a 1 I �E . 6 r• �. 1 , '•47 ' �i ,1 � AM ''El'�,���4- � ra •! Sr �-.,yr=.'Y•�,�' '7 , FA Ac, f� _ ram•. ~ !�, ',..1} 3 01 n ,e± - A! ^wy sj;`P ;. . f {;T' •i I ' 1 _.TVi�.i�[ S; S - •- t •' is - Q _.a-Nw- \ y3 i r�3p-tr -• �6- - i j:.. .�} _.,a.�<<:.; ,�• rj ''f _ r? t ernFS Ii` �•� -'� tl�— _..� �� r�� a•+E A 1„ i�. 1 _ -_- =''t _ r 17 �7 46 9 T � �>� K....,.i • � + ..:I._ 77" Zil MIS -00+T' IM OL 44 ',�;� `` ``ti �_ 7 �� , •,!` K.C. C.C.E.S. NORTR ��� •`�"c� _ �?� 1 t � � AL Ef,oS, An ` SCALE: 1 200 _ ,4,: - . ..... _ ..... _. _ s` ;,...; 4 '`• -�` ' DOWNSTREAM DRAINAGE ROUTES TALBOT�lvRIDGE CORE 'PROJECT NO. 04120 �p 28 05 09Iz712oa6 King County Road Services Division Department of Transportation KSC-TR-0222 201 South Jackson Street Seattle, WA 96104-3856 September 21, 2006 Cliff Williams, P-E. P.D. Box 2401 Kirkland, WA 99116 . 02:16p Cliff Williams Belmont Ho 2069331049 p-1 WED 1U:37 FAX 425893849E Belmont Homes Cliff Home F 2001lo09 4(Z,( Post -it" Fax Nat 7671 Caie Pa9 T From 7 ! Co./Dept Co. Phone 4 Phone # Fax it Fgx M RE: Road Variance L05VO066 — Talbot Ridge Estates_- Relate d_File,L05PON7 Dear Mr. Williams: Thank you for your application for variances fi om the King County Road Standards (KCRS). You requested variances from Sections 2.12 and 2.13 of the KCRS concerning the entering sight distance (ESD) onto, and the stopping sight distance (SSD) along SE 192nd Street. A • crest vertical curve at the intersoction with 102nd Avenue SE limits sightlines. We reviewed your proposal to reconstruct the vertical alignment of SE 192nd Street to improve the, SSD io meet the. American Association of State Highway and Transportation Officials' (AASM) miinimunis. A minimum 280 feet of SSD should be provided utilizing -a two -foot target . This would•require up to five feet of fill=on• S-E 1.92116 Street, -weft of the intersection : with .1026f A•venue-SE.--f approve'a vgirianc;d-to`utilize AASHTD standards -for :tYie SSD vii&'. the following eoaditions: 1. The applicant roust adjust the driveway approaches to "the realigned SE 192nd Street. Letters have been provided permitting the driveway adjustments on the private properties. 2. Cleating must be performed within the right-of-way (ROW) of SE 192nd Street to maximize the ESD for the driveways along the reconstructed road. The proposed 415 feet of ESD to the left (west) on 102nd Avenue SE, exceeds the minima AASHTO criteria of 390 leet for the 10 over posted design speed of 35 mph. Actual approach speeds from the west are reduced by the curvilinear horizontal alignment as evidenced by the measured 32.2 mph 85th percentile eastbound speed on SE 192nd Street. I approve a variance for reduced ESD to the left (west) with the condition that clearing be performed in the ROW to provide.a minimum 415 feet. The available ESD to the right exceeds the KCRS mimmtum of 490 feet. The Department of Development °and Environmental -Services (DDES) will be detemiining the cross` sermon for the 'reconstructed road snd zeview3ng the engineering subrnittal.for compliance with the KCRS.. The requested variance forthe proposed'six percent horizontal curve • - superelevation oa SE 192nd Street was not npcessary: Your proposal ears to PE C,TI kI I i 1 - SEP 2 7 2UO6 .,:.. .: ..: .... m ....i A . i I Sep 28 06 02 : 1 7p Cliff Williams Belmont Ho 2069321 049 p . 2 09127/2006 WED LQ:37 FAX 4256930490 Helmont Homes - - - Cliff some 0002/004 Cliff Williams, P.E. September 21, 2006 Page 2 saperelevatian criteria in Table 2.2 of the KCR.S if a three percent superelevation is provided for the 360-foot horizontal curve radius. The design details should be coordinated with the reviewing agency, the DDES. This decision applies only to King County Read Standards identified in the vatic ice request. All other design requirements in the KCRS and other regulations, such as surface water management and zoning, must still be satisfied fora land use permit application. The applicant retains the rights and privileges afforded by King County Code and adopted Public Rules pertaining to roadvariance processing (KCC 14.42, PUT 10-2). This variance decision is valid for one year from date of letter unless an associated land use pem4it is pending or submitted within the one year period. In these cases, the vartame decision is valid for the duration of the permit processing A copy of staff s analysis, findings, and conclusions is enclosed. If you have any questions, please call Craig Comfort, Road Variance Engineer, Traffic Engineering Section, at 206-263-6109. Sincerely, Paulette Norman, P.E. County Road Engineer PN:CC:kc cc: James Sanders, P.E., Development Engineer, Laud Use Services Division (LUSD), Department of Development and Environment$] Services (DDES) Pete Dye P.E., Senior Engineer, LUSD, DDES Linda Dougherty, Division Di=Wr, Road Services Division (RSD), Department of Tra.asportation (DOT) Matthew Nolan, P.E., County Traffic Engineer, Traffic Engineering Section, RSD, DOT Fatin Kara, P.E., Supervising Engineer, Traffic Engineering Section, RSD, DOT Kris Langley, Senior Engineer, Traffic Engineering Section, RSD, DOT Craig Comfort P.E., Road Variance Engineer, Traffic Engineering Section, RSD, J)OT aep 28 06 02: 17p Clif-F Williams Belmont Ho 2069331049 p.3 09/.27/2006 WED 10:37 FAX 4256436496 Belmont Homes Cliff Home Z003/004 O Sing county Road 9ervioes Division Department at 42aoepartatian Traffic BnelaeeriN Saab= NOS HSG'l-0282 2Di south Ja kwm Street Seattle, WA 98104 September 21, 2006 TO: Variance File FM: Craig Comfort, P.E., Road Variance Engineer, Traffic Engineering Section RE: Road Variance L05VOD66 - Talbot Ridge Estates — Related File L0SP0007 Applicant's Pmsernation: I . The Talbot Ridge Estates preliminary plat las 271ots and fronts SE 192ad Street and 102nd Avenue SE. Variances are requested for reduced entering sight distance (ESD) looking to the left (west) from 102nd Avenue SE onto SE 192nd Stems and for reduoed stopping sight distance (SSD) along SE 192nd Street for the 250 feet of urban frontage improvements. A crest curve along SE 192nd Street at Mud Avenue S. limits sight lines. The King County Road Standards (KCRS) minimum ESD for the 10 over posted design speed of 35 mph is 620 feet, and the minimum SSD is 250 feet. 2. The measured ESD to the left (west) from 102nd Avenue SE is 340 feet Sightlines are restricted by trees along the north edge of the right-of-way (ROW) at the inside of a horizontal curve. With clearing in the ROW, ESD can be improved to 415 feet. With the trees removed, fencing and strictures along property lines would restrict the sightline_ The ESD deficiency is mitigated by speed reductions along the curvilinear road alignment and upgrade in the SE 192nd Street approach to the intersection. West of the site are cautionary 15 mph warning signs in both directions of travel. A speed study determined that the 85th percentile approach speed of eastbound vehicles is 32.2 mph. Accident report data for the last four years showed only one accident at the SE 192nd Street intersection. The ESD does not appear to be a factor in that accident. 3. The SSD over the crest vertical curve to the east of the intersection with 102nd Avenue SE does riot meet KCRS. The applicant proposed two alternative designs, one meeting KCRS based upon a six-inch target and one meeting the American Association of State Highway and Transportation Officials' (AASHTO) Dual SSD criteria with a two -foot target, A minimum of 317 feet of downgrade adjusted SSD would be provided. The profile based upon the aix-inch target would result in reconstruction of 1,100 feet of SE 192nd Street with fill sections to four feet deep. The profile meeting the AASHTO two -foot target would result in reconstructing 700 feet of SE 192nd Street with Mis to five feet in depth. Note that both altematives propose filling on both sides of the crest curve because the toad cannot be Towered due to utility conflicts and the intersection approaches on 102nd Avenue SE. The applicant requests a variance to use the two -foot target profile because of extensive construction for the six-inch target profile, Letters have been provided from homeowners along the adjusted roadway that will allow for driveway adjustments for the realigned vertical profile. The applicant provided an analysis showing that the ESD ad SSD for the driveways along the road reconstruction are either improved or equivalent to the existing conditions. Staffs Findim and Conclusions: 1. Clearing should be performed in right-of-way (ROW) to the extent possible to enhance the ESD. The minimum AASHTO ESD for the 35 mph design speed is 390. CIearing will provide over 400 feet of ESD. 2. The design of the southeast quadrant of the intersection of 102nd Avenue SE and SE 192nd Street will be reviewed by the Department of Development and Environmental Services. The minimmn curb return radius and transition paving tapers must be evaluated. 3. The proposed SSD variance with a minimum of 317 feet of SSD is more than the downgrade adjusted AASHTO value of 280 feet (Exhibit 3-2) for a 35 mph design speed. The two -foot target alternative for the revised vertical profile would result in fewer problems with driveway adjustments and result in a lower construction time period. 4. The Department of Transportation's Traffic Engineering Section files shows two accidents at the intersection in the past five years. In addition, two accidents were within 190 feet of the intersection. The proposal to improve the SSD should improve the safety along the road 5. A variance was also requested on resubmittal for a non-standard superelevation design. This variance request was not necessary because a superelevation design per 'Fable 2.2 of the KCRS can be provided. Sep 11 07 03:59p Cliff Williams Belmont Ho 2069331049 p.2 July 31, 2006 Mr. Craig Comfort King County CIP and Planning Section 201 S Jackson Street MS KSCTR-0317 Seattle, WA 98104.3856 RE: Talbot Ridge Estate Preliminary Plat Road Variance File No. LOSVO066 Dear Sir: 10033 SE 192°d Street Renton, WA 98055 I understand Belmont Homes, Inc. plans to develop a site adjacent to my property at 10033 SE 192nd Street. Cliff Williams of Belmont Homes, Inc has advised me that King County will be requiring regrading of a portion of SE 192nd Street west of 102"d Ave SE to improve site distance conditions. I further understand that this work will require some regrading of my driveway. Please be advised that I am willing to allow the regrading of my driveway on my property to accommodate the proposed improvements on SE 192nd Street, Yours truly, Roger M McDonald Sep 11 07 03:59p Cliff Williams Belmont Ho 2069331049 p.3 August 7,2006 Mr. Craig Comfort King County CIP and Planning Section 201 S Jackson Street MS KSCTR-0317 Seattle, WA 98104-3856 RE: Talbot Ridge Estate Preliminary Plat Road Variance File No. L05VO066 Dear Sir; I understand Belmont Homes, Inc. plans to develop a site across the street from my property at 10042 SE 192nd Street. Cliff Williams of Belmont Homes, Inc has advised me that King County will be requiring regarding of a portion of SE 192°4 Street west of 102'4 AVE SE to improve site distance conditions_ I further understand that this work will require regarding of my driveway. Please be advised that I am willing to allow the regarding of my driveway and connecting "turn out" to accommodate the proposed improvements with the understanding that I am able to review and give input to the plans and work. I would like specific attention given to storm water drainage and to the existing landscape to create a safe and pleasing driveway. Yours truly, /I,, � rWW dedo ° Michael W. McKee Arlene L_ McKee 13337 SE 195" ST Renton, WA 98058 3. OFFSITE ANALYSIS: Upstream Tributary Area No upstream drainage is received by the property. A possible area of tributary upstream area was investigated but, deemed not tributary as described below. There is a 2.1-acre basin which sheet flows to a depression on the eastern side of 102 4 Avenue SE which coincides with the south property line extension of the project site. See Upstream Basin Map exhibit on the following pages. There was no defined conveyance system found from this low area and no apparent sign that the storm water ever overflowed the road here. There was also no indication of any concentrated runoff collecting on the western side of the property. It appeared that drainage is simply infiltrated into the depression and would remain on the east side of the road. It was therefore, assumed that this drainage would not reach the subject property. Ln 9w .em 44 'XI JLW, 7 r -2-L 14 k,)/ or Al ry jI :0 3 IT9- ; tv 7 all 1 AL Cb JL "Map_ w Woo jh p 419-1 fit "doff ON AM .e I L,4 ok isr UPSTREAM BASIN MAP TALBOT RIDGE ESTATES CORE NO. 04120 Downstream Analysis RESOURCE REVIEW The site is located within the Black River Drainage Basin which is within the Duwamish- Green River Watershed. Resources listed in the KCSWDM were reviewed for existing/potential problems within the study area, i.e. the site and within 1-mile of the site along the downstream drainage route. FEMA Maps: FEMA map dated May 16, 1995 numbered 53033C0987F was reviewed. The site is not located within a flood plain. Sensitive Areas Folio: The King County Sensitive Areas Map Folio was reviewed to confirm whether or not wetlands, streams or floodplain areas, erosion hazard areas, landslide hazard areas, or seismic hazard areas are located within the study area. See attached sheets on the following pages. Along the existing downstream route, drainage is received by a wetland identified as 20 on the Wetland sheet. There is an unclassified and a Class 2 stream downstream of the site per the Streams and 100-Year Floodplains sheet. Along the existing downstream route, there is an erosion hazard area and landslide hazard area that appear to be associated with the unclassified stream. These areas are delineated on the Erosion Hazard Areas and Landslide Hazard Areas sheets. There are no seismic hazard areas within the study area as shown on the Seismic Hazard Areas sheet. DNR Drainaize Problems Maps: See attached iMAP exhibit on the following page delineating complaints within the study area. Also, see complaints filed with King County. Note that none of the complaints are directly adjacent to the property and that the `proposed' discharge point for this project is into the ditch along the north side of SE 192"d Street, which has no recorded downstream complaints. See field investigation following this Section for a description of the existing downstream route and discharge downstream route. a Greek Puget 2 Sound 3b s51 so . 11 Low Graeri f 4, e 14 MNI Creek 4 wadanc s Open Water Basin Sour:daries Sub -basin 3oundaries 2 Lower Cedar River O 16 4 Ft 22 � 23 19b 26b `ep , Y 21b 27b 24b s 9 21b 76 100b '6sb 12 15 16 75 22b 31b 23 25 24 26 28 30 19b 32b 29 lash 37 .106b 38 39 n Creek fD7b 99 98 35b Orr 30 7 48 49 71b 77 40b 84 53 11 42b 60b 68 70b 43b 55 56 ib 47 58 57b v Y . - _ - rs ' ' � �,, . �h � � ,_ ( ��� � VY . '"" __ 7 r T��� tik �4 i. J l+ A LQ King County Renton d S 7 rh Si i AP �LG ~�I a tWO91142KM 2 S.. !I1 1 1 � CI ZOOS K,:r4 Coon y d:J:.. n• � - a - 4.6$ft y Legend county Boundary 1r�n'w�r X Mountain Peaks A^Qra= Drainage Studies _ Neighborhood Drainage Projects Parcels Regional Stormwater Facilities Lakes and large Rivers Residential Stormvs, ater Far ilibec Streams Commercial Stormwawr Facilities Drainage Complaints Highways Incorporated Area S tre etx I c 4nti i ne information included on this map has peen complied by King County staff from a varfety of sources and is subject to change without notice. King C Hakes nc representations cr wafrarties express or implied as to accuracy, completeness. timelines; ^r righls to the .;se of such information. King Cr shall not be liable for any general. special. indirect. incidental. or consequential damages including. but rot limited to, iost revenues or loci prefits result he use or misuse of the information contained on this map. Any sale of this map or information on this map is prohibited except by written permission c aunty )ate. 3-19-2007 Source King County iMAP - Stormwater(httD.7lwww.metrokc.aavfGiSIiMAP) ,62FEB, 23. 2005 3:02?M KING CO, Wltu Ha, 0977 P. 9/12 MX(G COUNTY WATERS LAND RESOURCES DAqSX0N DRAjNkGE Jxv.EsTiGAnoN REPORT 5 A ' wVEb' GATION REQumr Type - 'ROBLEM:I).�✓ �v . r_ o ?a b ` -* o. 003 c� X-CE Date. ., Received from: (Day) (Eve) [AME• PHONE Anniti~ss: PL S ca r_ S zip OCATION OF PROBLEM.,EP DWFERENr ".ccess Per nisaian Granted ❑ Call F- W (Would. Like To Be F-Mmt) Rt Lo P -P% —rt4kffJ, 0. A-. VAUA--, GM,vui a. at name: J�/Ll�G[s -'- �' Lot No: .Stook No: �d r envies invo ved: No. field iyVwfigsdonrCQUjr46d z/a S T R Parcel No. Ito Kro1.I Thlros: New A.JP Basin CouncilDistrict City Charge No._ . Wvmz Citroen notified an `� + �ij " � by: � phme leave in person 10$ aA-V �SPoo� T on by OR No fir action rtcommended becaase: Leant agency loss been noified: _ Problem has been corrected. No problem has been. idenfified. Prior investigation addresses problem - SEE Fu X # Private problem - NDAP will not consider boaw=-, Water originates ow ite aAd/ nf=ighbormgparceL _Other (Specify): _-, ,TE CLOSED- �101 n� By: 10 fB, 23, 205"' 3,02PN���`r=SKIN ca,. •,:x:NO. g977 °P, 101212 and Land Resource Division DRAINAGE INVESTIGATION REPORT FIELD INVESTI AMN DMAIIS OF R VXMCu&TiQ - ADARM r IA" MM-, EL. J. r$OM 20.852.5fi74 TZ PAGE TROLL PAIN 60 DATX 5. T. DIVDs[ON MUM - SAD Sloe visit with Harry Trapp on 5-"3. There Is $ me eras on on the steep bank to the East of W PL. S. (p Wate row and he would Bice sorry technical assistance. Th& orosion is caused by a break in a r ADS pipe approWmately 2Q` above fhe road In the bank. The origin of this pipe Is not kftOwn. Hal`ty plans on connec ft the pipe to the interior drain he Instv1W behind the curb a few years ego beaausi the`dowtsft ern end ofthee 4" ADS b plugged wiFh sedinlenf due to minimal grade. Tins will ellminate the erosion issue. Harry would also la assmance with the tnliowii (1) Is Tract V part of the NGPV Aavording to the Rgoorded Plat documelrt, only ttte Southernmost 25` of Tract `C' is Mt of fht NGP£ 7) Can the H.O.A. remove the blackberries ftm Ttrad `C' and replaW with other plantings to miailnbm erosion? contact Jim Ballweber at King County PO-2g 4M9) to determine if a permit Is re(auired. J{m map also be able to help with the ype of punting best surfed fDr hMWO erasion control. Is S.192'd ST. Renton CL or is it maklt lned by KC? S.192"' ST is wIft Renton 'CL and Is maintained by Renton. ,4) Can they replace Bkddxwrbs with other plarltings in tho c4 of RentoWs easement on KC property? Contact Bernard Thompson at King County (206-296-7456) to appiy far a pence. ETCH 9 t r l Tract °Cr I V 1 "3 ! I I Irr 1 1 1 .! 71 t = FEB, 23, 2005 3 01PM KING CO, WLRO NO, 0977 wNG Courrrx w* rsat.A►rm Lmw REsoURCES DIM1(jN DRAINAGE 1NVES TiGAUON REPORT rrVPS' G4[ -n0N REQUEST ?ROBIEi: PG-aJe.C— ZECErvm By: Ar-i ela CJe— kP3 OK'd 6v, W l r !I 1 27 e.7 V 1 0—",— Typo Deceived from: . �R � f � �') (Eve) f_.__� �A4MR; f tr _ Pxcm S 5 _ (e, 7 0 ADDRESS: /93 . --'` q4h -�L �v -L city. �- �, s � p � �" OCATION OF PROBLEM, IF DM RFC, r. a� fcceas Permission GraHted ❑ cam Fuse (v'oald Ua: To Be "I fo w 40 9 -rAl 1-0-J j--7e c�e- w t. 4a -ems �a _ }f ?za " e ,J i w - pang. -r" i ew iat name: ry4Uk9t a 1JA —7-0—E Lot No: Block No: itber agencies involved: No.field invwdo ion required - _ -.DP _ Basin ` Council District — Charge No. NSE: Citizen notdied on by: IV" phone —1 emw in person mot- --° t4t� 5r<t-, -= SPOSMON : -T=ed to on ^ f T by . OR- No fartlrra acthm racamxuended because: Lend agmcy has been motifred: Problem has b= cornered, No problem has been identified. - Prior investigation addresses pr&lem: SEE If = # _ Private pmbl= - NDAP will not consider becamw: Water originates onsite andior on neighboring pal. kTITT CLOSED: 11"3 By. FES, 23, 200� 3;02PM LRD N0. 0977 °. 8/12 _. FE Na_ : 200.0194 ICING COUNTY NAW- PRYUM FRM ADDRESS.19MI 9#m Place south, City of Renton PHONE: (253) 252 -6905 DRA WAGE IlMSTIGAIUON REpoRT ' . DATA? OF SMAnOId: WOS-03 bMIM b[IyM71GATION DtwvtSTIGATE,D BY: V� Pac=Wa onto the site on MOM at 7:30 AM to iuv esUgaft an Maury A mrt a pr+opmy to the Souk. c#'h+lats_ Freed tW Las a Fmc&y Pon& Tbq xvcd nodfication float a fe = was to be conshu bd along thWr property bm& A irks was cunSburted some distance fim dw p opuly I �,■ey arc WoWczWg if ou-t fiance wM be r—tstigatinn do t it and the pe&aaw fmm was installed at The City afRemn Waftuhs& it vm it pMem of the City afReatm for mu on woad the water ama. It is as 8-9 W high cbafnlbk iiwe.11M Project bfmvpr of is W. Ri&Mminm 'The mon lame e fiam fhe City of ftntm TW endoud atb the %= was wA m the watetalred I apolre to hib about the inquiry dMrs. Freed. He bald = tlud they ne dome vft flte p wjmt and tip hum was iasta W at the ongbW bm a * is knoted ar tbve downsw m imt xhe gym_ A=r lM to him they abandaoed ft piss of iast m1bg tic fum nm w the pagmty 6 Freed due to so= baexdnry dsspuft aM bbsmoWsvn& other a&cem# p mpext r sr ffic NR silo offhe waofiedw& v*nvd Mrs. Fizd'to brim p w his pautriss m I ` PL So. .� DNTS 1 E•,, Rasidxntial Houses 192 �--.�__ .,...__...._...._.� 9e A've. 6E I Freud ^_ #194_14 ! a! • •a ■. i_4� ................................... wa.R.Ra ■_.rr.r►.... Ra■r■•arw..,.Ri......w i �•. Ncwly 1I 0ded t— ft ACSSO11. slop ' ■■■rl.rara R! w' � r■.■l�rr �'y•'�. +wa F ra►. ■.r�►ran ■ Pumong and •. l [blotine Station ■ ■ • i ar r � • a �• •R . 1 s •■'■a ■a.lal■w•■• ■ w r R 1R e 200 Sues. '■ ■r■•R FACU2rY �FEB. 23. 2005 3:00PM KI%16 CO. WLRC ' MOW P. 3/124 KING COUNTY WATER AND LAND R SOUNtrs DMSTON /T DRAJNAGT hE TIGA.TION REPORT` /, - � S IN VES CIATx0.4 REQUM Type C _ AORLEM: 0/24'AJA C a-,--- G-G= Date: J//S/r? Z7 Received :from: eryi I S LTA. -$ r 19 `- AW A DDRESS: J�.� � — p--j`'%City JC C`nJ' O J - State—t. ,� Zip )CATION OF PROBLEM, IP DIFFEREMr. ~ :cess Permission Granted El Call Fiirsrr (Wmdd Lace To Be Presw) _-it name: Lot No: Stock No: hex' ces :evolved: No field inve 'on "Ted /. S T R Parcel No, �}, f Xron _ Th.Bros: Never' I W Basin Council District V�� Charge No. i,..spvNSE: Cittr notifird one by:.Irone „ lett+r _______ :a person 00 AJ 4s%- - L Iz550116'e 0t�c,s Erb G r . a c o il.. -o-6v4 wL , I ;POSMON: Turned to ou ! ! by. OR- No r"mfher action recommended because: — Lead agency has been notified:_- Problom etas been core irA No problem has been identified, Movinvestigation addresses problem: ' SEE n.L. �€ Private problernm. 1 NDAP will not consider because: Water originates ondte atidlor on neighboring par *L _ _Kother (Specify). FEB. 23, 2005 2,59PM KING CO, VI+ I<D NO. 0977 P. 2/12 Fite No: NAME: Cate Assigned problem Type ;J r-.*�'�`!,:"� t"•fix .L;�4'r�Y,�'#$1 � 59. .°r, :.,;;' � Cbsed b- %21•S'i''R`.i�r:'� " 11 t. il,�l 4J .i '�' To ;.n.d•!'flhii.;, ToScreener J ; R Q -FEB. 23. 2005 3; 03PM KING CO. WL ----,. NO. 0977 j&wG Cou-NTY W xrER Arras LAMA RuouRcn DIVISION DRAINAGE TNWSTTGATION REPORT / _ IlV VMMG! n0N RFQUMr P. 11 /12 ,.,.,.r...� �r Received from= Aboffi: U 1_1 C-7 &—jk1JAAJDk-5:j1,- PH.M., .ADDRESS: X City_ ���� Statc t,& Zip � ��� )CATION OF PROBUR-4 W DnTMM4-r-- Awess Permisrrou Granted ❑ CallAW [WouM Life, To Be�nwemo „ zz -4fxv 1-9 tt ,ame: L*t No: $ No: A,s 1 160qv- - " - �a s T R Parcel N'o.__ J52 gjC!N KrollW& Tb.Bros: New ,dP Basin CowDil District ^ Oty char a No. M0MM: Ctftm notiSed on � by: � phone letter is penon ,�_� �aa sue, • - ?.b Splay to -,-TLtr-& �L'7 r 6sSr4 I 414 1 edv� 1*A S d 33I3J +wT, S 4 AM> p oBPFIDN: �mnad on a _ f -f _ b? .__ OR; N'o further action recommended because` _ LeaA agency has been noised: _ Problem has been corrected. X Na problem has b= identified. Pr= my on addresses problem si,FHX0 _ Private problem. - NDAP wM not consider liccause; Water originates onAte andlar on neigbboritng parcel. `. --aches (Sp )= rr CLOsm: 12 1 `t IQ3 By; 94_. " woV) 06D t U 3. 2005& 3:03PM�,,�— KING CO. WLh� KING COUNTY D","' eatofN R�saurocs Water and Land Resource DIA916n DRAINAGE INVESTIGATION REPORT FIELD INVESTIGATION DETAILS OF 1RV 9=GAM*W: 0977vy �-P. 12i1 mom 253-&%-889 MPARE $ IMOM PAGE -- 8 DAU 10 ii On site 10-10-03 to Investigate repot of vegetation. 'eyesore' at Talbot Estates facility #D92539. Facility appears to be functioning properly and in good shape. Ali vegetation appears to be kept in good order ecept for a small amount of vegetation growing in the gravel access road. This facility has a S.U.P. for the H.O.A. to maintain ft vegetation within bmdk SEMWEE _ S. 194th ST \S, �' Lot 4 ,.1A Lot 1 R I Lot 3 ! Lot 2 f ! 1 � go Cr M ;FEB. 23, 2003 3; 0GPM KING CO, W! RD NO. 0977 KING COUNTY WATER. RIND I.A1 D RESOURCES DrVXSI[ON . DRAiNA.GE.INVESTYGATION REPORT MAMS t ATION>MQtEr /' 03 OK'd bv- Received from:�}v y (Day) 4AME: h r PHONE 73— A PLESS. 95 576-- Z,&m n ACATlo'N OF PROW3K IF DI WMWr: 4ccm Per mayioa Cwan%d kt name: Other aEoncies inva3.ved: Cyr Z 2 S V4 S T R P.;`I2� A (Eve) (___ State. zip Yze5-5 Call ,Mini (Wowd Uh To Be Rtmmt) Lot No: Block No: Parcel No.,L Th Bros: New RD-PBasin 6G I-.- council ]stria __ % _ City Charge No. S`PON.SL Citi= notified on _ by.� phone letter in person a � � �� [SPOSWxvN: Tumed to on I I by___, OR. No furflw action recommended because: Lead agency has been noted:..y V' • j— �n Problem has bwn corrected No problem has bem identified. Prior invagigatlon addmmm problem; .SEE S# Private, problem - NDAP will not consider bwawse: Water originates onsite and/or an adghbcmtg parceL Dther (Specify): ,,ATE CLOSED. / By: ►'rM LJ. 2U 5Z UOF "- WK!NG CU, WL DOW, ,J � ;CVO. 0977d?P, 4'12ok�-;„_1 Complaint 2002-0207 kozhenevsky Investigated by Andrew McDonald on March 19. 2002 I attempted to male Contact with complainant Alex Kozhenevsky, but l was unable to reach him aflw leBvmg several masmWs- on his cell phone voice T visited the site as noted above and took photographs of the site. The site sits adjacent to a wed],and and was reviewed under DDES building permit number B96R0578. The site was reviewed for both wetland and viz dmp concerns on site. Wetland conditions iuieluded a notice on tMe for the set aside of wetlands on the property to be maintained as native gtowth per the SAO. The genwal area has been the subj b ct of previous groundwater complains. Complainant's property sits at the bottom of the hill on the west side of Talbot RD S. The building pad for the residence sits approximmly ten feet below the road grade for Talbot RD S. 11a yard mtrrormdmg the m de= while landscaped with plantings and grass lawns has many varieties of Ruslm growing on site whore lawn .has given way to wet saturated sans. Seeps and s rmp flow from the eastem side of lot and flow towards the wetlands behind the residence and detached garage on site. Water is also flowing from cracked areas of sbx= walls mmoundmg tho staff way leab* to the fiont entrance of the residence_ The eastcm yard ofthe property is hWdy sahmftd and would need to have intercoptor Umiches placed and discharged to wetlands regwring the complab=t to contact DDBS regarding worHV within the SAO burr. SE 192nd ST -=0 �Q 1� 3 0 ttb, 1NG Co. NLRD "NO. 0477 P. 6/12 Complaint 2003-0011 Kozhenevsky - Investigated -by Andrew McDonald on Januairy 9, 2003 Visited site aid met with Mr. Kazhenevsky. He is concerned with waW entemg his site from Talbot RD S and from S 192"4 ST. The County -City boundary litre is S IV4 ST. On the north sidd of the street is the City of R lom ang on the south k& is King County. Mr. Ko2henevs1W is con�d, about the water he gets from his eastern and northm property ]fines which border Talbot RD S to the cast and S 192d ST to the nor& He beliem that failure to makdain the toadsidc Glitch on the wedtem side of Talbot RD S and along the southem side of S 192d ST, east of Talbot RD have caused water to shy flow amss Talbot and onto his lot at the intersection. Mr_ KozJumovsky is hoping that King Comay Roads cart pr ovidc some relief in cleaning the ditches and keep water fiaam entering his site. Mr. Ko4mevsky also wishes to build a;retainmg wallhn*ary along his property Line. I reed him to Dl]ES for peittung and hearts. Madered;:21-M : 1 spoke to John meson at City of Reston Public Woxks/ Itnad Maiatensum I mluye d the proble= Mr. KoA mevsky rgar#ed to Mr. Thompson as thiis portion of riot -of -way is mated i by the City of Reton and not by King Comity Roads per BM Conner at King Cc Roads. I told Mr_ Kozhenev&7 that I had givem this complaint to the City of'R:eatom He would prefer dw his name not be given to the City nor his telephone number per Mr. 2 S Ighd ST Lol�i k tc cross Calvert �admg tv motets* ring Sguo�c Ctt, King County Soils Survey: The soils on site are Alderwood gravelly sandy loam. See Soils Map in Section 3A of this Report. Wetlands Inventory Maps: There are no wetlands on this site. FIELD INVESTIGATION Existing Course On July 26th, 2005, a site visit was conducted. The weather was warm, 85 degrees and sunny. The week prior to this site visit was moderately dry and warm. The downstream analysis begins at the western property boundary (point A). See Downstream Analysis Existing Course exhibit on the following pages. The drainage sheet flows southwest for approx. 120 ft. across three lots and discharges onto 99t' Place S. (point B). The flow continues south along the flow line for approximately 150 ft. until it enters a type I catch basin (point C). The flow continues south through an existing storm drain system consisting of 12" concrete pipe and type I catch basins for approximately 440 ft. The pipe enters a type I catch basin on the edge of a cul-de-sac at the south end of 99t' Place S. where there are signs of the flow passing over the top of the catch basin and flowing down the steep slope into the ravine (point D). The flow continues south through an SAO landslide area for approximately 75 ft. through a 12" corrugated metal pipe and discharges via a type 11 catch basin at the bottom of the ravine (point E). The flow continues southwest though the SAO landslide area via a stream channel for approximately 75 ft where it leaves the SAO landslide area and enters an SAO erosion area (point F). The flow continues west through the SAO erosion area via a stream channel for approximately 1000 ft. where it connects with another stream and exits the SAO erosion area (point G). The flow continues northwest along the stream channel for approximately 200 ft. where it enters a culvert which crosses under Talbot Road S. (point H). The flow continues northwest through the culvert for approximately 200 ft. and discharges west of Talbot Road S. (point 1). The flow continues northwest for approximately 350 ft. via a stream channel where it enters the Gallagher property which has a drainage complaint on file with King County Surface Water Management (point J). The flow continues north for approximately 150 ft. through the Gallagher property where it discharges into an SAO wetland (point K). The flow then discharges at the northwest edge of the wetland (point L) and enters a culvert which discharges on the north side of S. 192"d St. (point M). This point is approximately 0.6 miles from the project site. This ends the field investigation. 0 Incr Sheehan 1 f! 4.90 S.R1177007 w �3.:513 ,�::.�1,, ':tF 'J �• r°ia o � to �' � ,. ❑ > a ia,v � e^ ____-- if ie .1_ Burton s '?4 �c _ 1.41 Act 3 ;: ;-- ---, CD Goldman af, tiff 0l - Burton !. B, Ac-t Ac ` 653 ig 33_;a6 AC. Lelia M, Ruth 1.31 Ac. "j ,ram c- _ Robi ~I-50 Ac _;'.. 1 apt -1 Kenneth emu,i a9 .Ac.t 3.48 kl .f — - ---- - ` -- ---- — ---- -} if r i�si ' --�- f x f -��;ab�Ess NORTH �. �icltear� w «, you 170 3 as s:p SCALE: 1"=200' h G S- d. \k�• 4Y C 1 3c •�� T' 2�� � �,s' ., m ' 1�0 DOWNSTREAM ANALYSIS EXISTING COURSE .��� TALBOT RIDGE CORE PROJECT NO.04120 -- > 14 ISO a I � '.•-'� K 'i Jib �. z iN" � i� +lam :�r-..I +� = i -' '. OFF -SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Basin 04120 Talbot Ridge - Existing Course Subbasin Name: Subbasin Number: Ty—mbol Drainage Component Type, Name, and Size rauyag pon�at Descnptton. ape }a4e E from t c sgrFtor { wept see map Type: sheet flow, swa e, stream, channel, pipe. pond; Size: diameter, surface area drainage basin,,ve8etation, cover, depth, type of sensttivc area, volume % 1l'4 i,32Qproblem, �titpaets. site -A A-B sheet flow sheet flow site discharge adjacent lots 0' 0'-120' B-C C-D shallow channel pipe flpw roadway & adjacent property 120'-270' 270'-710' roadway & adjacent property D-E E-F pipe flow channel flow roadway & adjacent property adjacent property 710'-785' 785'-860' SAO Landslide Area SAO Landslide Area evidence of flow bypassing CB evidence of scouring F-G G-H channel flow channel flow adjacent property 860'-1860' 1860'-2060' SAO Erosion Area evidence of scouring adjacent property 114 1-3 pipe flow channel flow adjacent property 2060'-2260' 2260'-2610' adjacent property J-K K-L channel flow plug flow in wetland adjacent property 2610'-2760' 2760'-2960' WLRD Drainage Complaints SAO Wetland adjacent property L-M pipe flow adjacent property 2,960'-3,130' FIELD INVESTIGATION (continued) Discharge Course On February 22nd, 2005 a site visit was conducted. The weather was cool, 45 degrees and sunny. The week prior to this site visit was moderately dry and cold. The downstream analysis begins at the northwest corner of the property (point 1). See Downstream Analysis Discharge Course exhibit on the following pages. This is where the outfall for the site will be located. The roadside ditch, on the south side of SE 192nd Street, is well defined here and protected from erosion with rip -rip. There are standing pools of water in the ditch where debris is piled but there is no running water in the ditch at this point. The open ditch goes from the culvert under the existing driveway to another pipe before entering a catch basin (point 2). This CB is connected to the next CB on the north side of the road (point 3). There are a series of CB's, perhaps two that are not visible and may have been buried because of recent shoulder and driveway construction along the north edge of the road (point 4). The storm conveyance system does emerge around the bend of the road and still on the north side (point 5). The pipe was partially buried and covered with debris but looked to be 1 S-inch. From the end of this pipe the water enters a deep, rectangular shaped channel approximately 6-feet x 6-feet in size. The channel appears to be man-made and is heavily protected with large rip -rap. The channel goes through heavy underbrush and emerges from the property on the north side of the final easterly bend in SE 192"d Street (point 6). At this point the channel, the roadside ditch on the north side of the road, and a minor cut-off ditch from the north all combine into one grated catch basin before continuing west along the north side of SE 192nd Street in a combination of short culverts and open ditch. The ditch is heavily protected with rip -rap (point 7). Over topping of driveway culverts has happened along here but flow that remains in the ditch does not appear to be eroding the ditch. This ditch has not been well maintained and it appears that the overtopping of the driveway culverts and the ditch in most locations could be minimized by removing the large accumulations of debris in the ditch at the upstream ends of the culverts. The culverts are full of sediment; therefore it is difficult to determine the size. They appear to be 1 S-inch. There is no running water in the ditch at this point. This ditch continues west to where it drains to a 24-inch pipe and continues west under Talbot Road. The pipe invert is deep, perhaps 4 feet down below the roadway and heavily protected with riprap. There is no sign that the runoff overtops the road (point 8). This point is'/4-mile from the project site. The pipe enters a CB in Talbot Road that has a solid locking lid. There was no outfall found from this CB. Researching County records will be needed to determine the exact outfall location (see addendum that follows). All water within this basin converges about 1/4-mile further west (point 9) with stream flow from the south that passes under SE 192"d Street in a 36-inch CMP culvert. The upstream end of this culvert is partially buried with sediment deposited because of debris in the end of the pipe. The downstream end forms in a 20-foot diameter pool with the culvert end hanging about the stream channel by approximately 1-foot. The stream channel takes a 90-degree bend at this pool and parallels the road until it reaches the SR 167 highway where it continues west in a 48-inch pipe. This point is one mile from the project site (point 10). This ends the field investigation this day. Addendum to Investi ag on 4n March 18"' , a sunny dry day, the manhole at point 8 was revisted to remove the locked top since City of Renton records where not clear as to the existing conveyance system. After removing the top a 24-inch pipe entering from the ditch previously mentioned along with an 1 S-inch from the north along Talbot Road was found. The outfall pipe is a 36-inch going west, after taking a bearing on this pipe another locked CB was discovered about 100 feet west that was covered by dirt and landscaping (point A) and continues 200 feet west to a CB at point B then 50 feet more to a ditch at point C on the north side of SE. 192nd Street. The ditch is well defined and continues west to point 9 described in the previous investigation. There is no sign of overtopping or erosion in this ditch but the ditch is heavily chocked with vegetation between point C and point 9. This ends the 2nd field investigation. It was reconfirmed that this basin does not enter Spring Brook Creek above the fish farm. RAT ja OT S IOWA I NOT IiI ��t n-1. �02'- T Jf� 1�v 68 A. 4V r' Y4 m it; 1 �ZL ,Pr.-1-i I ­ . 80 vW I 1� 09 18 BA 4' P'M .mr Low 75 So? _00 rTE .3 A Wtlkf) E 1XS 4 1? �71 j --" . . - , ;' , ;.x 4� Z'_—z ... .. Fli IT G" w pro pis K us. 14 spit -71 DOWNSTREAM ROUTE DISCHARGE COURSE TALBOT RIDGE ESTATES CORE NO. 04120 ilt 4. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN: A. Hydraulic Analysis The drainage analysis was modeled using the King County Runoff Time Series software. The onsite soils are Alderwood (AgC), KCRTS group Till per the Soils Map attached on the following pages. The site is located in the Sea-Tae rainfall region with a location scale factor of 1.0. EXISTING CONDITIONS EXISTING BASIN BOUNDARY The existing drainage basin boundary will include the property area, 190,123 square feet, less the existing pavement within the property boundary that will remain as is along the west boundary that is part of the road section for 102°d Avenue SE, 4,011 square feet, less a portion of Tract D that will remain undisturbed, 23,860 square feet, plus proposed improvements along SE 192nd Street and 102nd Avenue SE outside the property boundary, 18,660 square feet. Existing ground cover will be modeled as Till -Forest. The following information was used for generating time series and flow frequencies. EXISTING CONDITIONS (04120ex) Total Area = 180,912 sq. ft. or 4.15 acres GROUND COVER AREA acre Till -Forest 4.15 "rWo 4. • d f C , M ftj�i • a qb+l f rod[ ` MI .,r - o + •` 394 - w S A w 1onMA AL • + o ¢ rt� , w.-��,.._� fM. .. � '� F3; � S:R l �� ; � i ..- oa'-.� WB�r� _tea, :. _—• tii - - r Tank• . .-- � 7 A �.� � j GCS"' Y" �.� a ��� ■ i 'M,R,'i� .� y S �:�t•' �r • • � �" y, �JJ AVE • 3 "• •' Y • •a .a•• y 1 ad �,e li . •,�� �� � �, r� s .� :d C�cl !' - ^ S� °.Ji• t ' t r t#t iDrive i i�- a 1J } r■ VW Aec r �1, f Sk, k t°•.� r r 9 FV.1. SOL :_��� s"'1iq: „ S r � � ;: .1 . u l -� �4re4?'3 i • � •ir s Sa' • i i � �.r ( , - F ` � i;�.;�k 7' �y. 1 y ,� Z a; :�� e � raileY ,f� r4 � �_.....-...�� :-'; A • L � � . � -'.�. ,, �,y • � • Y• � �.,, , mar � '� � � t 1� � `'\ ;{ � � ' Rr� � Age` • i • �r'�� .;�"y,..,''�,r ;, 1.�,,.: F S 4 � '� } � � • ••' a '••� •�� `��g�—�� � 'i �'n-'t'�4 44 SAE ;.Fk od A f Y4 �2� • •'1 SOILS MAP TALBOT RIDGE E STATES +Z 0 00RE NO.04120 6.4.1 W-ETPONDS —BASIC AND LARUE — METHODS OF ANALYSIS FIGURE 6.4.1.A PRECIPITATION FOR MEAN ANNUAL STORM IN INCHES (FEET) ST 1.1 0.54" (0.045') ( _= Incorporai .-iama River/Lal i — Major Roe NOTE: Areas ea4. _...._ _� ._,..,.. .. r.... inches unless rainfall data is available for the location of interest 2,° The mean annual storm is a conceptual storm found by dividing the annual precipitation by the total number of storm event$ per year ST 1.0/ ST1.0 1w0%a .. n.% LA1.o LA1.2 v. J v (U.034' ) (0.04T) result, generates large amounts of runoff: For this application, till soil types include Buckley and bedrock soils, and alluvial and outwash soils that have a seasonally high water table or are underlain at a shallow depth (less than 5 feet) by glacial till. U.S. Soil Conservation Service (SCS) hydrologic soil groups that are classified as till soils include a few B, most C, and all D soils. See Chapter 3 for classification of specific SCS soil types. 2005 Surface Water Design Manual 1/24/2005 6-71 Flow Frequency Analysis Time Series File:04120ex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.262 2 2/09/01 18:00 0.071 7 1/06/02 3:00 0.194 4 2/28/03 3:00 0.007 8 3/24/04 20:00 0.115 6 1/05/05 8:00 0.201 3 1/18/06 21:00 0.169 5 11/24/06 4:00 0.335 1 1/09/08 9:00 Computed Peaks Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 0.335 1 100.00 0.990 0.262 2 25.00 0.960 0.201 3 10.00 0.900 0.194 4 5.00 0.800 0.169 5 3.00 0.667 0.115 6 2.00 0.500 0.071 7 1.30 0.231 0.007 8 1.10 0.091 0.310 50.00 0.980 DEVELOPED CONDITIONS The proposed project includes constructing 22 single-family residential lots with associated roadways and utilities. Access to the site will be via 102"d Avenue SE. Half - street improvements on 102nd Avenue SE along the property's east frontage , including pavement widening and installation of curb, gutter, and sidewalk, will be completed as part of the subject project as well as more extensive improvements along SE 192nd Street which will address existing inadequate stopping sight distance. FLOW CONTROL BMP REQUIREMENTS Per Section 1.2.3.3 in the 2005 KCSWDM, projects subject to Core Requirement #3 must apply flow control BMPs to impervious surfaces as directed by this section to either supplement the flow mitigation provided by required flow control facilities or provide flow mitigation where flow control facilities are not required. Flow control BMPs must be selected and applied according to the basic requirements, procedures, and provisions detailed in Section 5.2 and the design specifications for each BMP in Appendix C, Section C.2. Since approval will be required for the subdivision as well as the building permits for the newly created lots, both kinds of flow control BMP implementation are required as described in Section 5.2. Individual Lots Per Section 5.2, for individual lots, implementation shall be in accordance with the "Individual Lot BMP Requirements" in Section 5.2.1. The individual lots on the subject project are smaller than 22,000 square feet and therefore, fall under the Section 5.2.1.1 "Small Lot BMP Requirements". Since full dispersion and full infiltration are not feasible, one or more of the following BMPs listed under Section 5.2.1.1 (3.) must be applied to an impervious area equal to at least 10% of the lot for lot areas up to 11,000 square feet. The "Reduced Impervious Surface Credit" per Appendix C, Section C.29 will be applied to the lots for the subject project. A "Restricted Footprint" will be the technique used to receive the "Reduced Impervious Surface Credit". Without the reduced impervious surface credit requirement, the maximum impervious area per lot is calculated using the criteria in the 2005 KCSWDM page 3-27 and K.C.C.21A.12.030. The proposed development is urban residential. The site is R-6 zoning. Per K.C.C.21A.12.030, the maximum impervious area per lot is 70%. The total lot area is 114,855 square feet. The maximum impervious area for the lots is therefore, 70% * 114,855 square feet = 8 0,3 99 square feet. The average maximum impervious area per lot is 80,399 square feet / 22 lots = 3,654 square feet per lot. Per the 2005 KCSWDM page 3-27, the maximum impervious area per lot would either be 4,000 square feet or the maximum impervious area as stated in K.C.C.21A.12.030, whichever is less. The impervious area will therefore, be equal to 80,399 square feet for all the lots since 3,654 square feet is less than 4,000 square feet. Utilizing the restricted footprint technique to receive the reduced impervious surface credit, the maximum impervious area for the lots will be 60%, 70% (lot area) - 10% (lot area). The maximum impervious area for the lots is therefore, 60% * 1 14,855 square feet = 68,913 square feet. The distribution for the impervious area over the lots will be decided at building permit such that when the total impervious area for the lots are summed, the total lot impervious area will not exceed 68,913 square feet. Subdivision Projects Per Section 5.2, for subdivision projects, credits are applied for the application of flow control BMPs per Table 5.2.2A (p. 5-12). Per Table 5.2.2A, the flow control BMP that will be implemented is the "Perforated Pipe Connection" which has no facility sizing credit. DEVELOPED BASIN BOUNDARY The developed drainage basin boundary will include the property area, 190,123 square feet, which includes the existing pavement within the property boundary that will remain as is along the west boundary that is part of the road section for 102nd Avenue SE, less a portion of Tract D that will remain undisturbed, 23,860 square feet, plus proposed improvements along SE 192nd Street and 102nd Avenue SE outside the property boundary that will be captured within the proposed conveyance system, 14,649 square feet. Developed Drainage Basin Area Bypassing Proposed „Combination Water Quality Detention Vault A bypass area equal to 3,821 square feet of landscaped area within the storm drainage easement within Tract D will be compensated for within the detention calculations. Developed Drainage Basin. Area Tributary to Proposed Combination Water Quality, / Detention Vault The developed drainage basin boundary tributary to the proposed combination water quality/detention vault is equal to The developed drainage basin area less the bypass area or 190,123 square feet — 23,860 square feet + 14,649 square feet — 3,821 square feet 177,091 square feet. DEVELOPED CONDITIONS BREAKDOWN TRIBUTARY TO VAULT Total Area = 177,091 sq. ft. or 4.06 acres AREA DESIGNATION AREA(s . ft. 102 AVE SE AND SE 192 ST R/W 23,031 Existing Impervious 4,011 Proposed Impervious 16,478 Pervious 2,542 SE 192 ND PL 20,414 Impervious 19,210 Pervious 1,204 DEVELOPED CONDITIONS BREAKDOWN TRIBUTARY TO VAULT continued Total Area = 177,091 sq. ft. or 4.06 acres AREA DESIGNATION AREA(s . ft.) TRACT A 3,066 Impervious 2,676 Pervious 390 TRACT B 3,444 Impervious 2,703 Pervious 741 PORTION OF TRACT D 12,281 Pervious 12,281 LOTS 114,855 Impervious 68,913 Pervious 45,942 DEVELOPED CONDITIONS BREAKDOWN BYPASSING VAULT Total Area = 3,821 sq. ft. or 0.09 acre AREA DESIGNATION AREA(s . ft.) PORTION OF TRACT D 3,821. Pervious 3,821 The following information was used for generating time series and flow frequencies. DEVELOPED CONDITIONS TRIBUTARY TO VAULT 04120d Total Area = 4.06 acres GROUND COVER AREA(acre) Till -Grass (Landscaping) 1.44 Impervious 2.62 DEVELOPED CONDITIONS Total Area = 0.09 acre BYPASSING VAULT (04120by) GROUND COVER AREA(acre) Pervious 0.09 21 A.12.030 A_ Densities and dimensions - residential zones RESroEAlTIAL Z 0 RURa� UFA" uRSAa REMY Rmsm rnAt E S STAlIDAFM RA-2.8 RA-5 RA -to RA-20 tM R11 R4 R-G R-8 R•12 R-18 R-2b R48, [771 9see t MMdttr. 0-2 02 0.1 OAS 02 1 4 a 8 12 18 24 48 OWSKIDO dul= duke dine d"c duI dulac dulac du/c dupe dule dulae duly dufaa URWACM (15) NWWM uu 0emftr GA PA 6 9 12 18 27 36 72 DMMN ag UAWA4M &Uac dufac dWae dint du/a dtdac duhx dale dutac (1) (22) 8getmum Onnity: 85X 86% 857E W% 7S% 70% 65% M 112) 1121 02) (181 (18) (12) (18) 118) (18) (19) w1 Minimum E.at 135 It 135 ft 135 n -138 ft 3811 351t 30 ft 30 ft 30 rt 30 ft 90R 3o ft as ft rurdm (7) (71 (sl Minunum Sfntet 30 ft 30 it M 30 ft ae ft 201t loft 10 It loft loft loft loft le ft Sewatic {9} (9) (sF [91 R) [7) (81 [e} (8} [8} [81 {8} [8} p1 Minimum lnteftdr S ft loft 10 ft loft 5 ft 5 ft sit S ft 9 tt lift S ft 5 It 5 It Sedwick (91 191 (9) (9) (71 (7) {10) (10) (101 110) (3) (18) Base Height 40 ft 40 ft 40 ft 40 It 35 ft 35 it 38 ft 35 ft 38 ft Gait 80 ft 8o ft wit (4) 45 ft tG It elf ft 80 R wit (14) 114 (141 (14) 114) MetdmeM 25% 29% 13% 12.5% 30% 30% 98% lay. 75% am BS% 96% 904E kmpe-k— [11) 111) {11) (11) (11) ill) Smlaca. [is) (19) h9} {19) Pelpfrtags {51 12-2 (King County 6-00) Flow Frequency Analysis Time Series File:04120d.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return ?rob (CFS) (CFS) Period 0.764 6 2/09/01 2:00 1.54 1 100.00 0.990 0.626 8 1/05/02 16:00 0.988 2 25.00 0.960 0.918 3 2/27/03 7:00 0.918 3 10.00 0.900 0.680 7 8/26/04 2:00 0.818 4 5.00 0.800 O.B18 4 10/28/04 16:00 0.811 5 3.00 0.667 0.811 5 1/18/06 16:00 0.764 6 2.00 0.500 0.988 2 10/26/06 0:00 0.680 7 1.30 0.231 1.54 1 1/09/08 6:00 0.626 8 1.10 0.091 Computed Peaks 1.36 50.00 0.980 Flow Frequency Analysis Time Series File:04120by.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.008 3 2/09/01 2:00 0.019 1 100.00 0.990 0.004 7 1/05/02 16:00 0.010 2 25.00 0.960 0.010 2 2/27/03 7:00 0.008 3 10.00 0.900 0.002 8 3/24/04 19:00 0.008 4 5.00 0.800 0.004 6 1/05/05 8:00 0.007 5 3.00 0.667 0.008 4 1/18/06 16:00 0.004 6 2.00 0.500 0.007 5 11/24/06 3:00 0.004 7 1.30 0.231 0.019 1 1/09/08 6:00 0.002 8 1.10 0.091 Computed Peaks 0.016 50.00 0.980 B. Detention Routing Calculations Conservation (Level Two) Flow Control shall be utilized to mitigate for the developed storm drainage flows. The live storage portion of the combination water quality/detention vault will satisfy this requirement. The vault will be located in the northwestern corner of the subject property. As a requirement of the 2005 KCSWDM Adjustment Request (File No. L05VO061), a 10% volumetric factor of safety will be applied to the detention facility. See copy of approved adjustment in Section 2 of this Report. The proposed vault includes compensation for the developed bypass area. The vault (04120vlt.rdf) was sized based on the 2005 KCSWDM and KCRTS Computer Software Reference Manual. See attached KCRTS printouts. Per the KCRTS printout, the vault surface area is 5,353 square feet. Per the 2005 KCSWDM Adjustment, the required surface area was adjusted with a 10% volumetric factor of safety. The vault to be constructed will therefore, have a minimum surface area equal to 110%*5,353 square feet = 5,888 square feet. The prim overflow for the vault is the riser pipe on the control structure. The water surface elevation above the riser for the 100 year, 15-minute developed flow is calculated assuming all orifices are plugged. To pass the 100-year, 15-minute return period storm, 3.82 cfs, through a 15" overflow riser will require 0.46 feet of head per the following equation: Q = 9.739DH3/2 or 3.82 = 9.739(1.25)H31. See attached flow frequency analysis on the following pages for calculation of the 100-year, 15-minute return period storm. The primary overflow elevation would therefore, be equal to the elevation of the top of the riser plus the amount of head required to ,pass the 100-year return period storm, Elev. 368.83 + 0.46 feet = Elev. 369.29. Retention/Detention Facility �111--x1 Type of Facility: Detention Vault Facility Length: 83.64 ft Facility Width: 64.00 ft Facility Area: 5353. sq. ft Effective Storage Depth: 9.89 ft Stage 0 Elevation: 359.09 ft Storage Volume: 52941. cu. ft Riser Head: 9.74 ft Riser Diameter: 15.00 inches Number of orifices: 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 0.91 0.069 2 6.30 1.63 0.133 4.0 3 8.40 0.81 0.021 4.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 359.09 803. 0.018 0.000 0.00 0.01 359.10 857. 0.020 0.002 0.00 0.02 359.11 910. 0.021 0.003 0.00 0.03 359.12 964. 0.022 0.004 0.00 0.04 359.13 1017. 0.023 0.004 0.00 0.05 359.14 1071. 0.025 0.005 0.00 0.06 359.15 1124. 0.026 0.005 0.00 0.07 359.16 1178. 0.027 0.006 0.00 0.08 359.17 1231. 0.028 0.006 0.00 0.27 359.36 2248. 0.052 0.011 0.00 0.46 359.55 3265. 0.075 0.015 0.00 0.65 359.74 4282, 0.098 0.018 0.00 0.84 359.93 5299. 0.122 0.020 0.00 1.03 360.12 6317. 0.145 0.023 0.00 1.22 360.31 7334. 0.168 0.025 0.00 1.41 360.50 8351. 0.192 0.026 0.00 1.60 360.69 9368. 0.215 0.028 0.00 1.79 360.88 10385. 0.238 0.030 0.00 1.99 361.08 11455. 0.263 0.031 0.00 2.18 361.27 12472. 0.286 0.033 0.00 2.37 361.46 13489. 0.310 0.034 0.00 2.56 361.65 14507. 0.333 0.036 0.00 2.75 361.84 15524. 0.356 0.037 0.00 2.94 362.03 16541. 0.380 0.038 0.00 3.13 362.22 17558. 0.403 0.039 0.00 3.32 362.41 18575. 0.426 0.041 0.00 3.51 362.60 19592. 0.450 0.042 0.00 3.70 362.79 20609. 0.473 0.043 0.00 3.90 362.99 21679. 0.498 0.044 0.00 4.09 363.18 22697. 0.521 0.045 0.00 4.28 363.37 23714. 0.544 0.046 0.00 4.47 363.56 24731. 0.568 0.047 0.00 4.66 363.75 25748. 0.591 0.048 0.00 4.85 363.94 26765. 0.614 0.049 0.00 5.04 364.13 27782. 0.638 0.050 0.00 5.23 364.32 28799. 0.661 0.051 0.00 5.42 364.51 29816. 0.684 0.052 0.00 5.61 364.70 30833. 0.708 0.053 0.00 5.80 364.89 31850. 0.731 0.054 0.00 6.00 365.09 32921. 0.756 0.055 0.00 6.19 365.28 33938. 0.779 0.055 0.00 6.30 365.39 34527. 0.793 0.056 0.00 6.32 365.41 34634. 0.795 0.056 0.00 6.33 365.42 34687. 0.796 0.058 0.00 6.35 365.44 34794. 0.799 0.061 0.00 6.37 365.46 34901. 0.801 0.065 0.00 6.38 365.47 34955. 0.802 0.070 0.00 6.40 365.49 35062. 0.805 0.076 0.00 6.42 365.51 35169. 0.807 0.081 0.00 6.44 365.53 35276. 0.810 0.0B3 0.00 6.63 365.72 36293. 0.833 0.098 0.00 6.82 365.91 37310. 0.857 0.110 0.00 7.01 366.10 38327. 0.880 0.119 0.00 7.20 366.29 39344. 0.903 0.126 0.00 7.39 366.48 40361. 0.927 0.135 0.00 7.58 366.67 41378. 0.950 0.142 0.00 7.77 366.86 42395. 0.973 0.149 0.00 7.96 367.05 43413. 0.997 0.155 0.00 8.15 367.24 44430. 1.020 0.161 0.00 8.35 367.44 45500. 1.045 0.167 0.00 8.40 367.49 45768. 1.051 0.168 0.00 8.41 367.50 45821. 1.052 0.169 0.00 8.42 367.51 45875. 1.053 0.169 0.00 8.43 367.52 45928. 1.054 0.171 0.00 8.44 367.53 45982. 1.056 0.173 0.00 8.45 367.54 46035. 1.057 0.174 0.00 8.46 367.55 46089. 1.05E 0.174 0.00 8.47 367.56 46143. 1.059 0.175 0.00 8.48 367.57 46196. 1.061 0.175 0.00 8.67 367.76 47213. 1.084 0.185 0.00 8.86 367.95 48230. 1.107 0.193 0.00 9.05 368.14 49247. 1.131 0.200 0.00 9.24 368.33 50264. 1.154 0.207 0.00 9.43 368.52 51281. 1.177 0.213 0.00 9.62 368.71 52298. 1.201 0.219 0.00 9.74 368.83 52941. 1.215 0.223 0.00 9.84 368.93 53476. 1.228 0.611 0.00 9.94 369.03 54011. 1.240 1.320 0.00 10.04 369.13 54547. 1.252 2.230 0.00 10.14 369.23 55082. 1.265 3.310 0.00 10.24 369.33 55617. 1.277 4.420 0.00 10.34 369.43 56153. 1.289 4.820 0.00 10.44 369.53 56688. 1.301 5.190 0.00 10.54 369.63 57223. 1.314 5.530 0.00 10.64 369.73 57758. 1.326 5.850 0.00 10.74 369.83 58294. 1.338 6.160 0.00 10.84 369.93 58829. 1.351 6.450 0.00 10.94 370.03 59364. 1.363 6.730 0.00 IN 11.04 370.13 59900. 1.375 7.000 0.00 II.14 370.23 60435. 1.387 7.250 0.00 11.24 370.33 60970. 1.400 7.500 0.00 11.34 370.43 61506. 1.412 7.740 0.00 11.44 370.53 62041. 1.424 7.970 0.00 11.54 370.63 62576. 1.437 6.200 0.00 Hyd Inflow Outflow Peak Storage Stage Elev (Cu-Ft) (Ac-Ft) 1 1.54 0.96 9.89 368.98 53742. 1.234 2 0.76 0.22 9.74 368.83 52938, 1.215 3 0.99 0.17 8.32 367.41 45361. 1.041 4 0.92 0.18 8.55 367.64 46546. 1.069 5 0.81 0.11 6.79 365.88 37142. 0.853 6 0.82 0.05 6.04 365.13 33117. 0.760 7 0.63 0.05 5.69 364.78 31283. 0.718 8 0.68 0.04 3.75 362.84 20896. 0.480 Hyd R/D Facility Tributary Reservoir POC Outflow Outflow Inflow Inflow Target Calc 1 0.96 0.02 ******** ******* 0.97 2 0.22 0.01 ******** 0.24 0.23 3 0.17 0.01 ******** ******* 0.17 4 0.18 0.01 ******** ******* 0.18 5 0.11 0.01 ******** ******* 0.11 6 0.05 0.00 ******** ******* 0.06 7 0.05 0.00 ******** ******* 0.06 8 0.04 0.00 **#***** ******* 0.04 ---------------------------------- Route Time Series through Facility Inflow Time Series File:04120d.tsf Outflow Time Series File:vltout.tsf POC Time Series File:04120out Inflow/Outflow Analysis Peak Inflow Discharge: Peak Outflow Discharge: Peak Reservoir Stage: Peak Reservoir Elev: Peak Reservoir Storage: 1.54 CFS at 6:00 on Jan 9 in Year 8 0.963 CFS at 10:00 on Jan 9 in Year 8 9.89 Ft 368.98 Ft 53742. Cu-Ft 1.234 Ac-Ft Add Time Series:04120by.tsf Peak Summed Discharge: 0.969 CFS at 10:00 on Jan 9 in Year 8 Point of Compliance File:04120out.tsf Flow Duration from Time Series File:vltout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % % % 0.003 28457 46.407 46.407 53.593 0.536E+00 0.009 7540 12.296 58.704 41.296 0.413E+00 0.016 5599 9.131 67.834 32.166 0.322E+00 0.022 5236 8.539 76.373 23.627 0.236E+00 0.028 4902 7.994 84.367 15.633 0.156E+00 0.034 3883 6.332 90.700 9.300 0.930E-01 0.041 1910 3.115 93.814 6.186 0.619E-01 0.047 1725 2.813 96.628 3.372 0.337E-01 0.053 1300 2.120 98.748 1.252 0.125E-01 0.059 420 0.685 99.432 0.568 0.568E-02 0.066 18 0.029 99.462 0.538 0.538E-02 0.072 4 0.007 99.468 0.532 0.532E-02 0.078 9 0.015 99.483 0.517 0.517E-02 0.084 20 0.033 99.516 0.484 0.484E-02 0.091 38 0.062 99.578 0.422 0.422E-02 0.097 28 0.046 99.623 0.377 0.377E-02 0.103 26 0.042 99.666 0.334 0.334E-02 0.109 34 0.055 99.721 0.279 0.279E-02 0.116 19 0.031 99.752 0.248 0.24BE-02 0.122 17 0.028 99.780 0.220 0.220E-02 0.128 15 0.024 99.804 0.196 0.196E-02 0.134 9 0.015 99.819 0.181 0.181E-02 0.141 12 0.020 99.839 0.161 0.161E-02 0.147 13 0.021 99.860 0.140 0.140E-02 0.153 14 0.023 99.883 0.117 0.117E-02 0.159 11 0.018 99.901 0.099 0.995E-03 0.166 14 0.023 99.923 0.077 0.766E-03 0.172 8 0.013 99.936 0.064 0.636E-03 0.178 7 0.011 99.948 0.052 0.522E-03 0.184 6 0.010 99.958 0.042 0.424E-03 0.191 7 0.011 99.969 0.031 0.310E-03 0.197 3 0.005 99.974 0.026 0.261E-03 0.203 2 0.003 99.977 0.023 0.228E-03 0.209 4 0.007 99.984 0.016 0.163E-03 0.216 4 0.007 99.990 0.010 0.978E-04 0.222 4 0.007 99.997 0.003 0.326E-04 Flow Duration from Time Series File:04120out.tsf Cutoff Count Frequency CDF Exceedence - Probability CFS % % % 0.003 28579 46.606 46.606 53.394 0.534E+00 0.010 7710 12.573 59.180 40.820 0.408E+00 0.016 5608 9.145 68.325 31.675 0.317E+00 0.023 5201 8.482 76.807 23.193 0.232E+00 0.029 4884 7.965 84.772 15.228 0.152E+00 0.035 3824 6.236 91.008 8.992 0.899E-01 0.042 1885 3.074 94.082 5.918 0.592E-01 0.048 1700 2.772 96.854 3.146 0.315E-01 0.055 1179 1.923 98.777 1.223 0.122E-01 0.061 401 0.654 99.431 0.569 0.569E-02 0.068 19 0.031 99.462 0.538 0.53BE-02 0.074 5 0.008 99.470 0.530 0.530E-02 0.080 10 0.016 99.466 0.514 0.514E-02 0.087 21 0.034 99.521 0.479 0.479E-02 0.093 37 0.060 99.581 0.419 0.419E-02 0.100 27 0.044 99.625 0.375 0.375E-02 0.106 24 0.039 99.664 0.336 0.336E-02 0.113 37 0.060 99.724 0.276 0.276E-02 0.119 20 0.033 99.757 0.243 0.243E-02 0.125 16 0.026 99.783 0.217 0.217E-02 0.132 14 0.023 99.806 0.194 0.194E-02 0.138 11 0.018 99.824 0.176 0.176E-02 0.145 10 0.016 99.840 0.160 0.160E-02 0.151 13 0.021 99.861 0.139 0.139E-02 0.158 13 0.021 0.164 12 0.020 0.171 14 0.023 0.177 7 0.011 0.183 9 0.015 0.190 4 0.007 0.196 7 0.011 0.203 3 0.005 0.209 2 0.003 0.216 4 0.007 0.222 4 0.007 0.228 4 0.007 Duration Comparison Anaylsis Base File: 04120ex.tsf New File: 04120out.tsf 99.883 0.117 0.117E-02 99.902 0.098 0.978E-03 99.925 0.075 0.750E-03 99.936 0.064 0.636E-03 99.951 0.049 0.489E-03 99.958 0.042 0.424E-03 99.969 0.031 0.310E-03 99.974 0.026 0.261E-03 99.977 0.023 0.228E-03 99.984 0.016 0.163E-03 99.990 0.010 0.978E-04 99.997 0.003 0.326E-04 Cutoff Units: Discharge in CF5 -----Fraction of Time----- CutoffBase New %Change 0.057 I 0.95E-02 0.61E-02 -35.3 0.073 I 0.63E-02 0.53E-02 -15.1 0.089 I 0.49E-02 0.46E-02 -6.6 0.105 I 0.37E-02 0.35E-02 -6.2 0.120 I 0.29E-02 0.24E-02 -16.0 0.136 0.22E-02 0.18E-02 -17.0 0.152 0.15E-02 0.14E-02 -6.7 0.167 0.10E-02 0.86E-03 -14.5 0.183 0.62E-03 0.49E-03 -21.1 0.199 0.34E-03 0.29E-03 -14.3 0.215 0.21E-03 0.18E-03 -15.4 0.230 I 0.16E-03 0.00E+00 -100.0 0.246 I 0.98E-04 0.00E+00 -100.0 0.262 0.16E-04 0.00E+00 -100.0 There is no positive excursion ---------Check of Tolerance ------- ProbabilityBase New %Change 0.95E-02 0.057 0.056 -3.0 0.63E-02 0.073 0.057 -21.7 0.49E-02 0.089 0.085 -4.0 0.37E-02 0.105 0.101 -3.9 0.29E-02 0.120 0.112 -6.8 0.22E-02 0.136 0.125 -8.3 0.15E-02 0.152 0.149 -1.9 0.10E-02 0.167 0.163 -2.8 0.62E-03 0.183 0.179 -2.3 0.34E-03 0.199 0.194 -2.2 0.21E-03 0.215 0.210 -2.1 0.16E-03 0.230 0.216 -6.4 0.98E-04 0.246 0.222 -9.6 0.16E-04 0.262 0.229 -12.4 Maximum negative excursion = 0.019 cfs (-24.3o) occurring at 0.077 cfs on the Base Data:04120ex.tsf and at 0.058 cfs on the New Data:04120out.tsf Flow Frequency Analysis Time Series File:04120dl5.tsf Project Locaticn:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 1.25 6 8/27/01 18:00 3.82 1 100.00 0.990 0.884 8 1/05/02 15:00 2.68 2 25.00 0.960 2.68 2 12/08/02 17:15 1.74 3 10.00 0.900 1.00 7 8/23/04 14:30 1.52 4 5.00 0.800 1.52 4 11/17/04 5:00 1.49 5 3.00 0.667 1.49 5 10/27/05 10:45 1.25 6 2.00 0.500 1.74 3 10/25/06 22:45 1.00 7 1.30 0.231 3.82 1 1/09/08 6:30 0.884 8 1.10 0.091 Computed Peaks 3.44 50.00 0.980 C. Water Quality Volume Calculations Basic Water Quality Treatment shall be utilized to mitigate for the developed storm drainage flows. The dead storage portion of the combination water quality/detention vault will satisfy this requirement. The required volume was designed per 2005 KCSWDM Section 6.4.1.1. The following variables were used in the calculation: Volume Factor (f) = 3 Rainfall = 0.039 feet or 0.47 inches Area = developed basin tributary to proposed water quality facility Where Ai = area of impervious surface (sf) Atg = area of till soil covered with grass (sf) Atf = area of till soil covered with forest (sf) Ao = area of outwash soil covered with grass or forest (sf) V, = [0.9Ai + 0.25Atg + OJAtf+ 0.01Aj * (R/12) Vb = f* Vr Vb = 3*[(0.9)(2.62) + (0.25)(1.44)10.039 * (43560sf/ac) = 13,852 CF The 1st cell of the vault accommodates a dead storage volume of 25' *24' * 6.09' = 3,654 CF. The 2nd cell of the vault accommodates a dead storage volume of 25' *67' *6.09' _ 10,201 CF. The vault therefore, provides a total dead storage volume of 3,654 CF + 10,201 CF = 13,855 CF which exceeds the required 13,852 CF. 5. CONVEYANCE SYSTEM ANALYSTS AND DESIGN: The conveyance system for the site was designed for the 25-year, 15-minute and 100- year, 15-minute return period storms. Conservatively and for simplicity, the total KCRTS 100-year, 15-minute time step flow from the entire site tributary to the proposed detention facility was input into each pipe segment to confirm adequate sizing. See attached KCRTS Flow Frequency Analysis (04120dl5.tsf) in Section 4B of this Report. The 100- year, 15-minute time step flow for the entire site tributary to the proposed detention facility is 3.82 cfs. The tailwater elevation within the vault was derived from the KCRTS outfall information. The 100-year tailwater elevation is El. 368.98. The backwater analysis was performed to ensure that during the 25-year design storm, the headwater elevation in each structure does not exceed any of the rims and during the 100- year design storm, the maximum water surface elevation either does not exceed any of the rims or exceedance of a rim would be allowed if the topography would allow the overflow to be conveyed to the next downstream catch basin or if the topography could ensure that ponding would not cause structural damage. During the 100-year, 15-minute return period storm, all headwater elevations remained below the rims. Since all headwater elevations during the 100-year design storm remained below the rims, the headwater elevations during the 25-year design storm would also, remain below the rims. The conveyance system is therefore, adequately sized. The outfall design for Outfall 1 A is based on the developed 100-year, 15-minute return period storm, 3.82 cfs. Based on the velocities within the pipe upstream of Outfall 1A, the outfall was designed according to Table 4.2.2.A in the 2005 KCSWDM. The pipe upstream of Outfall I can carry a full flow of Q(full) = 1.49/n*A*R21*S112 = (1.49/0.012)(7r/4* 12)(0.5/2)211(0A1)1/2 = 3.87 cfs and a full flow velocity of V(full) _ Q(full)/A = 3.87/(n/4* 12) = 4.93 fps. To calculate the actual velocity within the upstream pipe during the developed 100-year, 15-minute return period storm to Outfall 1 A, Figure 4.2.1.G in the 2005 KCSWDM was used. See attached. The proportional discharge is 3.82 cfs/3.87 cfs = 0.99. The proportional velocity, based on Figure 4.2.1.G is 1.14. The actual velocity is therefore, 1.14*4.93 fps = 5.62 fps. A rip rap outfall was designed based on the discharge velocity falling within the range of 5 to E 10 fps per Table 4.2.2.A. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . .. ..... .. . JOB NAME: TALBOT RIDGE ESTATES PREPARED BY: G.fflrooks OB NUMBER; 04120 DESIGN STORM: 100 YEAR FROM CB TO CE FLOW fCPS ) PIPE LENGTH (FE E PEPE DIA- (IN) MANNING'S n VALUE OUTLET ELEVATION (FEET) INLET ELEVATION (FEEIL_ PIPE AREA (SQ M FLOW VELOCITY (FTISEP VELOCITY READ (FEET) TAFLWATER ELEVATION (FEET) FRICTION LOSS IFEET ENTRANCE HGL ELEVATION FEET) ENTRANCE HEAD LOSS (FEET) EXIT HEAD LOSS IVEET) OUTLET CONTROL ELEVATION (FEET) INLET CONTROL ELEVATION iFEET) APPROACH VELOCITY HEAD (FEET) BEND HEAD LOSS i (FEET), JUNCTION HEAD LOSS (FEET) HEADWATER ELEVATION (FEET) Rim FL 3A 3 3.82 621 12 0.012 357.09 367.70 0,79 416 0.37 368.98 0.60 369.58 0.18 0.37 1 3 4 182 88 12 0.012 36770 372.53 0.79 486 0.37 369.83 0.85 373.53 0.18 0.37 374,08 374 IL 0.37 031 000 37406 370.08 4 5 182 28 12 0.012 37253 372.61 0.79 486 037 374.06 0.27 374.33 IMS 9.37 37499 37442 0.37 OA9 000 37500 377.79 5 6 3 82 240 12 6,012 372.81 396.09 0.79 4.86 037 375.00 2.33 397.09 0.18 0.37 39764 397.65 0 37 0 uo 020 39749 400.93 6 7 3.82 23 12 0012 396.09 396.51 079 4.86 0.37 397.49 0.27 397.76 OIs 037 39831 398.1 t 0.37 0.00 ON 39794 40039 7 8 182 27 12 0012 39651 396.89 0.79 486 0 37 397.94 0.26 398.21 0.18 0.37 39976 39849. 0.00 0.00 000 398.76 400.39 6 9 3.82 103 12 U012 396.09 398.43 079 416 0.37 397.49 L00 399.43 0.18 0.37 39998 400.03 0.37 0.49 020 40035 405.52 9 10 382 96 12 0012 398.43 398.9[ 079 4.86 0.37 40035 0.93 401.28 0.-1-8 0.37 401 83 40052 0.00 0.00 000 40183 401. 0 u QN 9 11 3.82 64 12 0012 39843 404.00 079 486 037 40035 0.62 405.00 0.18 0.37 40555 405.57 0.00 000 0.00 405 57 411705 12 3.82 169 12 0.012 372.53 378.99 079 416 0.37 31 1 1,! 2 1 311.1 0.L8 0.37 380.54 360.58 1 0.371 0.49 Ono 38070 383.001 L2 13 3.821 log 1 12 0012 37899 387.57 0.79 4.96 0.37 7,� 388.57 0.19 037 38912 389.L4 0.37 0.49 ON 38926 396 W 13 14 3821 46 1 12 0012 387.57 387.804L-099I 4.86 0.37 38926 0.45 389.71 0. L8 0.37 390.26 38941 0.37 0.15 OMI 39004 392 V, 14 15 3.821 32 12 Ooiz 397.80 387.96 1 079 4.86 037 39004 0.11 390.35 OAS 0.37 390,90 389.57 0.00 0.00 Lo ---- I9090 ---- L2% -- 4.2.1 PIPE SYSTEMS — METHODS OF ANALYSIS 1.4 1.2 a a cc O a� F_ U 0 0.8 to uF C� a U to © 0.6 a w a a z O r- O 0.4 a O cc Q 0.2 7 FIGURE 4.2.1.G CIRCULAR CHANNEL RATIOS PROPORTIOIJAL HYD AULIC RADIUS \OPORTIONAL DISCHARGE PROPORTIONAL A PROP VE RTIONA -OCITY 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 RATIO OF FLOW DEPTH TO DIAMETER (dID) 1998 Surface Water Design Manual 4-21 911 /98 6. SPECIAL REPORTS AND STUDIES: Included in this section are the postmaster approval; Geotechnical Engineering Study by GEO Group Northwest, Inc., dated March 17, 2005; Rockery Design report by GEO Group Northwest, Inc., dated February 28, 2007; and an email from King County Metro confirming that Metro does not have service within the project area and will therefore, not need to review the street tree plan. CORE DESIGN Technical Men randum TO. file From Robert H_ Stevens, P.E. Date: March 19, 2007 Re: SE 1906 Street stopping sight distance, superelevation and runoff design Backaround The,plat of Talbot Ridge Estates has been required to construct frontage improvements along SE 192 Street. SE 192" d Street is classified as a Urban Collector Road_ Frontage improvements for SE 192nd will consist of vertical curb installed at 16 feet from road centerline. A Road Variance (L05V0066) has been granted allowing the use of AASHTO to meet the minimum stopping sight distance. As stated in the variance approval letter, "a minimum of 280 feet of SSD should be provided utilizing a two - foot target." Additionally, the letter conditions the approval with two design constraints: 1. The applicant must adjust the driveway approaches to the realigned SE 192nd Street. Letters have been provided permitting the driveway adjustments on the private properties. 2, Clearing must be performed within the right of way (ROW) of SE 192nd Street to maximize the ESD for the driveways along the reconstructed road. The variance letter further clarifies that a thee percent superelevation is appropriate for the 360 foot curve in the road St000ina Siaht Distance The posted speed on SE 192nd Street is 25 mph, the design speed has been specified as 35 mph, 10 miles over the posted speed limit. The base stopping sight distance requirement has been designed in accordance with AASHTO exhibit 3-1 which specifies a stopping sight distance of 250 feet for 35 mph design speed. Exhibit 3-2 modifies the stopping sight distance for various downgrades. The road variance has specified that a minimum stopping sight distance of 280 feet should be provided for this road, utilizing a two -foot object height, utilizing AASHTO standards for SSD, The preliminary design assumed a stopping sight distance of 317' which required a longer vertical curve and filling east of the 102nd Avenue SE intersection. With the reduction of the stopping sight distance to 280 feet, the vertical curve length was able to be reduced and the fill east of the 102nd Avenue SE was negated. The road profile was designed over the right of way centerline. Since the existing road east of 102nd Avenue SE is situated 17 feet north of the location of the right of way line, the proposed (and existing) road centerline elevation east of 102nd Avenue SE will be 0.34 lower than the centerline elevation as presented on the profiles. Therefore stopping sight distance will be achieved. As 192nd Street is widened out in the future, the road (and n� ht of way) centerline will be raised to maintain the 2% crown, matching with the 2% crown west of 102 . Superelevation Runoff Design (east end of„curve) The frontage curve for SE 192`d has been set at a three percent superelevation with a crown road transition on either end of the curve. The easterly transition from crown to superelevation was designed based on the WSDQT Design Manual, January 2005, Figure 642-5a, Superelevation Transitions for Highway Curves. The pivot point, as presented in this figure, will be located at the right of way line. For a 35 mph design speed and a 3% superelevation, a basic runoff length of 60 feet is suggested. Since the road will be designed as an Urban Neighborhood Collector with 16 offset from the centerline to edge of traveled way, an adjustment has been made for the width of the road over 12 feet (LR = LR(1+0.04167 * x, where x = distance in excess of 12 between pivot point and the furthest edge of traveled way, in feet). The final runoff length (LR) has therefore been adjusted to 70 feet (60 1.16663). Based on the equations in figure 642-5a, the distance from the normal crown to the level/crown section is 47 feet (LR*C/S = 70' *2/3 = 47'); the distance from the level/crown section to a full 2% slope is another 47 feet; the distance from the level/crown section to the PC is 49' (0.7 * LR= 0.7 * 70 = 49); the distance from the PC to the full crown slope is 21 feet (0.3 *70). These distances are presented on sheet C3.02. Superelevation Runoff Design (west end of curve The horizontal alignment of curves west of the frontage curve is very constraining, not allowing the full runoff design as stated above for the east end of the curve. A tangent length of 140 feet is present west of the design curve before another curve with a radius of 130 feet turns in the opposite direction. This 130' tight radius curve west of our improvements is substandard and would require a variance of some sort when it is improved. The 1993 King County Road Standards require a 135 foot radius for a design speed of 25 mph and 6% superelevation. With an assumption that the 25 mph design speed and 6% superelevation would be allowed, a basic runoff length of 105 feet and a final runoff length of 122 feet would be calculated by the same means as above. The distance required from the PC of the curve to the beginning of the transition would be a total of 126. If the west end of the frontage curve were designed to have the full runoff length as described above for the east end, the curve would need a runoff of 96 feet from the PC. With back to back appropriately designed runoffs, a total length of 222 feet would be needed from PC to PC, far less than the existing 140 feet that is available. It is clear that this area is extremely constrained. With this in mind, we have designed the westerly runoff length to be far less than what would normally be prescribed. We have opted for a runoff length of 25 feet which neatly ends the superelevation runoff at the same location as vertical curve matches existing grade_ Transition to the east East of the 102'd Avenue SE intersection, the existing roadway is constructed on the northern 30 feet of the existing 60 foot right of way. The intention of the design is to provide the appropriate curb locations based on the right of way centerline along the frontage of the subject property, but to maintain the existing alignment of the traffic flow east of the site. The channelization plan endeavors to keep the flow of traffic on the north side of 192"d, only providing a right turn pocket along the site frontage. 0 Page 2 REC. N0. L611179pp1 k4J ...1 14 30 'io 15 22 d R�757.Oa MIN 5 OOMkI 1.5' M fA} k1 IS IN GIMi0.' J I f L f �• ��...` �- \ �: ! t-647{ NF STAIPTO '21546 R81 � �sS� - 'YI; jjffEE�L ------- C�N flu 11_� -- ------ / RECpp0. 991U?�06L r7 3 0.6P----�-- N. uE KI kot SEC s-Z2-s 7 S��I.RLllll/ ��•. - '_----^'- N ITSw it AL -JOI.--__~�i � � `.v R�187.T.i6----- ---_ -} _7i ---- _--�` 149.92 'r.. N89�6'11w S03,19 I'•` 1- POMEA E�1,IENT a - u L�17.76 NO. 5676AEt R.M.00 4,452t 5F. 53421 SF. Ty, 4.47 -z 24 y' m v 3$60 6F. I9 5950k 5F, 25 4,SMI F. So �n 42,16415F. { � 4,1132 5f a in 4p2` 6 TRACT �T iD r ti 4.%It 5F. �' 4,5}6t 5F. a' 118 21 5p21t 5F. �' m 4911t fA: N n p M131t SF.(ROAD) = 5 65, �ol.� LC LC ROAD A 3"1 BF. 95' m 2 Jy. 16` 25' 40' 40' 4p' 43, 4D' 40' 40' AY� 12 s.664t 5F. � � 30 MM 1.5' MCI WE E LAE N X xw )I, DVT LOT 4, 9.6 N OF PROP. TMPoER SEC 5-22-5 a or 5 or P81P. UE M MEND a 15 IO 3563t SF. � 3hQmt SR 35S9t SF. R 3 5F. 3 a 1 I 3FJlt 6F. 35%k 6F. gS3 3 T1t 5F.�0 3 Wt SF. 2 TRACT G s 3 83t SF. I I 061 SF. Q s 3.915t 5F. I 5331k SF. 100, - NtW2r20'x �tsle - 3 i aG� NOTES L ALL TITLE ANFORiATIC K BHCLLN ON n* MAP HAS SM Wftb 1® PF01 AL.TA CO ""INT, PACIRC NORT1ALF5T TITLE CAl"k'ANY, ORDER 40. 581616, DATED 140o pER 16, 2004. N PREPAR►Y THIS nor, U*E SIi AFFECTING Me 61I VIFTED PROFEI E OTHE0$ESH R WAN T1�W ON THE AND POCLOSED BY THE IEFERCED PACPIC NORRAEST TITLE COMMENT CORE DE61L42 HAS RELIED LU40LLY ON PAC61C NORTWEST TITLE'S REIWmAE TATIO16 OF THE TRLEtS 01MITIDM TO PREPARE THIS SURVEY AHD 11-1EWIVRE COW DESW QJALM THE YL M ALOWTTACT' AND COPPL.ETO E68 TO THAT 1 XIIENT 2. T14I6 &IRNET' WI BEIM OBVIIL.E PHYSICAL I'p1 74 3'UXT C4TO1F Q* EXI5TFYs ON PMU RY B, 2005, ALL SURVEY CONTROL NDK'AT® AS 'F0161D' WAS RIECOVERFD FOR 11416 PROJECT N FEWIAW, 20M 3. PROPERTY AREA . F50J232 624ARE FEET (43646t ACRES). 4W 4. ALL D151 MICE5 ARE N FEET. P. T1415 15 A FIELD TRAVERSE MWEY. A SOMA R& SECOND COMIDI ED ELEGTI49W TOTAL STATION WAS USED TO HEAaM THE AMGULAR APO POTANCE RELATIONSHFiS 2EFIEW THE CONIROMNG HoUIEWATT04 AS 84M CLO&IGS RATIOS OF THE TIRAVHQ6E P£F OR DSCIBEDW TH06E BP%MW N LAC 532-I30-M ALL FEA&ja'IJf NSTRPBfF6 AND EE9UFW'B4T HA5 SM MAINTAINED N ADAUSTMENr ACCd1110NG TO K&AFACTURERIS OPECACATION6 ILTTHa4 CM YEAR OF THE DATE OF THIS SURvemISTAMM TEASTIRNG Eag-tENF RM BET3N C.avAf w AT AN MGS. milaLNE NTHN ONE TEAR OF THE DATE OF Pm SLRYEY 6. UTI_ITIEB OTNEt2 T1AN 7140BE 6F10'" MAY EXIST ON THIS SITE ONLY THOSE UrUTES GTH EVVEWE CF THEIR INBTA4L„6TKIFI Y1SfBLE AT C>taDIND SIIpFA.CE ARE N40M FEIEGN, =8WftXkD MUTY LOLATIO iB S IM ARE APPR0 "TE ONLT IPIDEFGRaPO CONCCITOW ARE 8401W As STRAW LNES WRWN J 6UwACE pTLTFY LOCATIONS BUT MAY CONTAIN 50NO6 OR CURYW NOT WO M 60S MEWAtoltiND LOCATIONS BHOIM Hmwt N MAY 14AVE PUBLIC 1111111DDPlD6.AIMN Fl M RIBL14-- RECORDS, CORE DESMN AMMI NO I.IABI-ITY FOR T+E (Z ACRACY OF 1- SECTION BUBDPMC N PER PAFAOapC# EAST I VOL K PG'8. 45.46, FaM AND HELD NORTWEST BEOTIOM CORER *0 HELD LIFE TO MID NORTH aIAR78R COR82 5A61S OF BEANW IS NORIN LINE OF NOWHiL ST a1ARTE.R OF SECTION p, Aa 40 N40' 40' 4p' 40', 16' 24' qO' �. Bs48'36•W 2GB.a7 •� � N88TT3i'N 139,20 Fp1M1 lir ]RHFR ~-S iME N Yy Nw)L GDYT LOf 4. '- --- - NO CAP SEC 5-22-S FCulO 5 FEH)R 10n E OF PROP. LAZE IRROLF PT. N 0.1' S 9F PROP. LW 29.39' w CF PROP. omm lo47* OX N aI. ' PRIRE SITE STATISTICS SITE AREA MOX3t 6F, (436t ACRES) •RGUI PERIGATCN 013M SF. NET SITE AREA 0TI1t SF. "ISM OP LATE 31 PIPOPOSED DENSITY 6,41 DIUACW DQSTNG XHING CLASSIFICATION R-11.60 PROPO%V USE SINGLE FAMV RESM1EN & SMITAW SEDER PROVIDER 50M CREEK WATER AND SEILER DISTRICT WA7M BII<KY SD06 CREEK "TIER MO MER DISTRICT SCHOOL DISTRICT KENT SGHOOL DISTRICT FRIE PISTRICT KING COWTY FIE DISTRICT 31 TELEPHONE SERVICE QUEST f1ECTRICTI'R' PROVIDER PUMT BOIFp ENERGY NATURAL GAS PROIADER RAM Sam EHEReT' SUTBACKB Fia7NT - 10 FEET SIDE - 5 FEET REAR - 5 FEET STREET 60EYARD - 10 FEET O+ARACE - 20 FLEET 11450 EATION AREA Wa1IRED 21 LOTS X 350 Sa FT.. 10330 82 FT. RECREATION AREA PROVIDED IOW Aa FT. LEGAL DESCRIPTION 24 THE NORTH HALF OF THE OF TIE NOWNAEST aIARTER OF GOYEWHENT LOT 4, SECTION 5, TMSWP 22 NORTH, RANGE 5 EAST, WL N KFL" CALR1•, ¢W9Wr.Tm DDEPE M MD SWEET AND IOM AVENK SOUT EAST ALBO EXCIrr THAT PORTION LTNG 60ITH CF AN EXTSTNG F7:NM DESCRIBED AS FOLLCIM. BFfiIHI@N' AT A POW ON THE IEST LFE OF SAID NORTRftT QUARTER 33J66 FEET SOUTH OF THE NORTHIEST CORDER THEW -OF. THQNCE SOUTH 00-425' IeST ALONG, 714E ILMT LFE OF SAID NORTHIIEST MWER 26L46 i,=I TO SAID EXISTING FENCE: THENCE ALONS SAID FENCE SOUTH 817015' EAST 2b.16 FEET, SOUTH BB"411-4' EAST MCI I FEET AND BOITH 081276' EAST AND EXiEN5104 118MCP UWO I$T TO THE EAST LINE OF &AV NORTHIMST QLARTER OF GOVERpBVT LOT 4, AND THE TERM OF SAID LIE TAX PARCEL/SITE ADDRESS TAX PAR M, C62205SO45 SITE ADDRESS: MOO PAIL 102ND AVE SE FOLMO 4 Lt]OWE 90N, -- MMC1E0 I• BtA55 B9c -- p.R1 N AM 0,$0 E CART, k9 MN gyp. 3 REFERENCES L THE PLAT OF PA MIDGE EAST I vol- 132, PG'6. 45-4A, 2. THE PLAT 0: HU-VIrW 4EQ4M YOL -M FGS. IE-16 3- THE PLAT OF HI•PARK, TRACTS- L5T ADPTITGM vOL. 14, P& 12 4. CITY OF RE NTON SHORT PLAT NO.059-85 BOOK 63 OF SURVEYS, PAGE 243 5- SHORT PLAT NO. M4199, [HOER WCOROM No. 86MI214 SASIS OF BEARII-SS N 89' 26' IS' I2 WRIJEE N TOE MOhF MC FO JND N PLACE AT THE N09M MOM COMM A43 THE NORTHRF-BT Wr-TION CORER OF 6M 5, W 22H, FM BE PM PEP I DA1UM N.4YA. W KING CONTY P0114T • RNTZ12 COPPER PH BET IN 4 NCH SGUAFE CONCRETE MON IE NF IA' BM= IRON hION ENT CASE LOCATED AT THE IXTEISEGTIOhk OF 5, r37HO, STFEET AND 89TH PLACE S. IE"ATION 3M,44 FT. M364 M) 000r>p �' Cp1El�7E IICN WM PaN0E8 I Y BIAS$ PL11C Dom 0.5' M CASE FUMO 4 mmaVM Nqt [aril PCN a 1 112 BRA55 CISx DOW a4' H CASE N89-26'15-w 3.45% 2616.62 MEASURED _ /n z016,sa P I 2 SITE VICINITY MAP APPROXI'WT@ SCALE 1'•4000' OlIJNER/APPL I CANT PD. BOX 2404 KIRKLAAD, WASi4mram 95080.2401 CONTACT: CLIP WILLWI6, P8 PHICHE 006) 714-1161 ENGINEER/PLANNER/SURVEYOR CCRE DE8M FIG, 1410 NE. 29T4 PL, SURE 0 13FI I EVM TLIASHNGTCN Spool C.CNTACT: ROMW BTevea PE - aGIEER MK346FL CHEW - PLANER STEPH E N A 5CHWI, PIA - SURVET'OR F4 M: f425) SSTs-1671 SCALE: 1 " = 40' C 20 40 00 O h z a en °. n gA� w ? 2" x .mh z Z z c� 4>_ • O z W �. -f W �O imp � W Z^CI N yM, +� a t 13 ��4 a��a z mWJ x �m L'i w Qza= n CL z L,) 0 Z 3 0 � d w 0 0 ff o IL d a SHEET OF .1 I 1 GEOTECHNICAL ENGINEERING STUDY PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192" ST. & 102" AVE. SE KING COUNTY, WASHINGTON G-1992 Prepared for Mr. Cliff Williams Belmont Homes, Inc. P.O. Box 2401 Kirkland, WA 98083-2401 March 17, 2005 GEO GROUP NORTHWEST, INC. 13240 NE 20t` Street, Suite 10 Bellevue, Washington 98005 Phone: (425) 649-8757 Email: info@geogroupnw.com L - —;i ?005 `�SGrou Northwest, Inc. &� c March 17, 2005 Mr. Cliff Williams Belmont Homes, Inc. P.Q. Box2401 Kirkland, WA 98083-2401 SUBJECT: GEOTECHNICAL ENGINEERING STUDY PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192ND ST. & 102ND AVE. SE KING COUNTY, WASHINGTON Dear Mr. Williams: G--1992 Geo Group Northwest, Inc. has completed an investigation of subsurface soils at the above referenced site in King County, Washington. This work was performed in accordance with our proposal to you dated February 28, 2005. Geo Group Northwest, Inc., explored subsurface soil conditions at the site by excavating ten exploratory test pits on March 9, 2005. Soils encountered in the test pits consisted of loose silty SAND and gravelly silty SAND with some cobbles overlying dense to very dense silty SAND and gravelly silty SAND with some cobbles at depths ranging from two to three feet below ground surface (bgs). Based on the results of our study, it is our professional opinion that the site is geotechnically suitable for the proposed development. The proposed buildings can be supported on conventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native soils. The loose site soils and fills are not suitable to support foundations due to their loose and variable condition. Based on the findings from our soil investigation at the site, we anticipate that the dense soil under the building areas are present between 2 and 3 feet below ground surface (bgs). Please refer to the text of the report for more specific recommendations regarding the site development. We appreciate this opportunity to have been of service to you on this project. We look forward to working with you as this project progresses. Should you have any questions regarding this report or need additional consultation, please feel free to call us. 13240 NE 20th Street, Suite 10 Bellevue, Washington 98005 Phone 4261649-8767 • . FAX 4251649-8758 March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page ii Sincerely, Geo Group Northwest, Inc. OZ6a6e-'-' zzt�� William Chang, P.E. Principal Geo Group Northwest, Inc. TABLE OF CONTENTS JOB NO. G-1992 Page 1.0 INTRODUCTION......................................................1 1.1 Project Description ............................................... 1 1.2 Scope of Services ................................................. 1 2.0 SITE CONDITIONS....................................................2 2.1 Site Description .................................................. 2 2.2 Geologic Overview ............................................... 2 2.3 Field Investigation ................................................ 3 2.4 Soil Conditions .................................................. 3 2.5 Groundwater Conditions ........................................... 4 3.0 SEISNUC CONSIDERATIONS ........................................... 4 4.0 STEEP SLOPE EVALUATION ........................................... 4 5.0 CONCLUSIONS AND RECOMMENDATIONS ............................. 5 5.1 General........................................................ 5 5.2 Site Preparation and General Earthwork .............................. 5 5.2.1 Temporary Excavation and Slopes .............................. 5 5.2.2 Structural Fill ................................................ 6 5.3 Spread Footing Foundations ......................................... 7 5.4 Permanent Basement and Conventional Retaining Walls ................... 9 5.5 Slab -on -Grade Floors ............................................ 10 5.6 Footing Drains ................................................. 11 5.7 Pavements......................................................11 6.0 MUTATIONS...................................................... 12 7.0 ADDITIONAL SERVICES ............................................. 12 ILLUSTRATIONS Plate 1 - Site Vicinity Plate 2 - Site Plan Plate 3 - Typical Footing Drain Detail APPENDIJ+i A: TEST PIT LOGS AND SOIL LEGEND Gen Group Northwest, Inc. GEOTECIINICAL ENGINEERING STUDY PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192"D ST. & 102"" AVE. SE KING COUNTY, WASMNGTON CAL 1.0 INTRODUCTION 1.1 Project Description The project site is located at the southwestern corner of the intersection at SE 192" Street and 102" � Avenue SE in King County, Washington. The site is near the city limits for Renton, Washington. The project site consists of a 4.36 acre undeveloped parcel_ We have been provided with a Conceptual Site Plan for the proposed development by Core Design which is dated December 17, 2004. According to the site plan the development will consist of 33 new residential lots, as shown on Plate 2 - Site Plan. Finish floor elevations for the new buildings were not provided at the time of this study. An access road and cul-de-sac turnaround are planned to be located near the center of the lot, running east and west off of 102' Avenue SE. We understand that a detention vault is planned for the northwestern corner of the project parcel with excavations on the order of 10 to 12 feet below existing grade. 1.2 Scope of Services The tasks we completed for this study were conducted in general accordance with the scope of work presented in our proposal dated February 28, 2005. The scope of work included the following: 1. Field exploration with ten test pits; 2. Preparation of test pit logs containing subsurface soil and groundwater observations; 3. Preparation of a written geotechnical report with the following recommendations: • Allowable soil bearing capacity and foundation design criteria; • Slab -on -grade floors and capillary break; Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 2 • Excavations, including temporary cut slope recommendations; • Grading and earthwork; • Drainage recommendations • Seismic design criteria • Earthwork and design recommendations for detention vault construction. The results of our subsurface investigation and our recommendations regarding the proposed development are summarized in the following report. 2.0 SITE CONDITIONS 2.1 Site Description We have been provided with a Conceptual Site Plan for the proposed development by Core Design which is dated December 17, 2004. We understand that the topography shown on the plan and incorporated into Plate 2 - Site Plan of this report is based upon lidar data and is therefore only an approximate representation of slope conditions. Based upon the site plan the site consists of gentle to steep west -facing slopes. According to the site plan the parcel ranges in elevation from approximately 408 feet at the east property line to 326 feet at the west property line. The majority of the site consists of gentle to moderate west -facing slopes. Moderate to steep slopes west -facing slopes with inclinations of 36 to 40 percent are located at the northwestern corner of the project parcel. The site is currently undeveloped and highly vegetated by grass, blackberry bushes, ferns, and trees. The trees at the site consist of primarily deciduous trees with a few mature evergreens located on the northern margins of the site. 2.2 Geologic Overview According to the Geologic Map of the Renton Quadrangle, King Counly, Washington, by MuIlineaux, dated 1965, the surficial geology in the site vicinity is mapped as Ground Moraine Deposits (Qgt). The ground moraine deposits consist of glacial till soils which are generally described as an over -consolidated mixture of sand, silt and gravel which was deposited during the Pleistocene Fraser Glaciation period about 14,000 years ago. Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 3 2.3 Field Investigation Geo Group Northwest, Inc., explored subsurface soil conditions at the site by excavating and logging ten exploratory test pits TP-1 through TP-10 on March 9, 2005. The test pits were spaced relatively equidistant across the site, as shown on Plate 2 -- Site Plan. The test pits were excavated to 4epths ranging between 5 and 11 feet below ground surface (bgs). Soil samples at varying depths were collected, classified and returned to our laboratory for moisture testing. The test pits were then backfilled with the excavated site soils and tamped into place by the excavator bucket. 2.4 Soil Conditions Soils encountered in the test pits consisted of loose silty SAND and gravelly silty SAND with some cobbles overlying dense to very dense silty SAND and gravelly silty SAND with some cobbles at depths ranging from two to three feet below ground surface (bgs). We interpret the dense silty SAND and gravelly silty SAND with some cobble soils to be the ground moraine deposits, glacial till, discussed in the geologic literature. The following table summarizes the depth to dense site soils at each test pit location: Test Pit Number Project Area Depth to dense native soil ft TP- I Southeast 3 TP-2 Southeast 2.5 TP-3 Southwest 3 TP-4 Southwest 2.5 TP-5 West 2.5 TP-6 Northwest 2.5 TP-7 Northwest 2 TP-8 Center 2 Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 4 TP-9 Northeast 3 TIP-10 Northeast 3 Copies of the Test Pit Logs are presented in Appendix A: Test Pit Logs. 2.5 Groundwater Conditions No groundwater seepage was encountered in the test pits. It should be noted that groundwater conditions may fluctuate seasonally, depending on rainfall, surface runoff and other factors. 3.0 Seismic Considerations Based upon our subsurface investigation at the site, it is our opinion that the project buildings may be designed using the Class C soil profile from the 2003 International Building Code, Section 1615.1.5. It is our opinion that the soils at the project site are not susceptible to liquefaction, due to the absence of groundwater within the loose soil zone. 4.0 Steep Slope Evaluation Based upon the site plan and our site reconnaissance moderate to steep west -facing slopes are located at the northwestern corner of the project site. Based upon the site plan the slopes have an inclination ranging from 36 to 40 percent from the horizontal. The slopes at the northwestern corner of the site are vegetated primarily by deciduous trees, ferns and bushes. At the time of our site visit the ground was covered with a large amount of leaves and forest floor detritus. We observed no signs of soil movement at the northwestern corner of the site, such as scarps or slumps. Based upon our site reconnaissance and the soils encountered in out subsurface investigation, the moderate to steep slopes located a the northwestern corner of the site appear to be relatively stable in their present condition. Preliminary plans indicate that a detention vault will be located at the moderate to steep slopes at the northwestern corner of the site. We understand that the detention vault may require excavations of between 10 and 12 feet below ground surface. The primary concern with regard to locating the detention vault in the moderate to steep slope area is that temporary excavation slopes be excavated in accordance with this report. Excavation slopes in the overlying loose Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 5 soils may be sloped no steeper than I H:IV. Excavations in the underlying dense soils may be sloped no steeper than 1H:2V. If groundwater seepage is encountered Geo Group Northwest, Inc. should be contacted to evaluate the stability of the excavation slopes. It is our opinion that the proposed detention vault may be located on the moderate to steep inclination slopes. Appropriate erosion control measures such as silt fences and plastic sheeting should be implemented during construction to prevent sediment laden runoff from being transported out of the work area. In addition, we recommend that permanent erosion control on the moderate to steep angle slopes should consist of jute netting and slope stabilizing vegetation. 5.0 CONCLUSIONS AND RECOMAMNDATIONS 5.1 General Based upon the results of our study, it is our professional opinion that the site is geotechnically suitable for the proposed development. The proposed buildings and detention vault may be supported on conventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native site soils. The overlying loose site soils are not suitable to support foundations. We anticipate that the dense soils are located at depths ranging from 2 to 3 feet below ground surface. Consequently we anticipate that a minimal amount of over -excavation may be required for the foundation at the building locations. 5.2 Site Preparation and General Earthwork The building pad areas should be stripped and cleared of surface vegetation and forest duff soils. Silt fences should be installed around areas disturbed by construction activity to prevent sediment -laden surface runoff from being discharged off -site. Exposed soils that are subject to erosion should be compacted and covered with plastic sheeting. 5.2.1 Temporary Excavation and Slopes Under no circumstances should temporary excavation slopes be greater than the limits specified in local, state and national government safety regulations. Temporary cuts greater than four feet in height should be sloped at an inclination no steeper than 1 H: I V (Horizontal: Vertical) in the loose site soils. Temporary cuts in the dense site soils may be excavated no steeper than IH:2V provided that no seepage is encountered. If groundwater seepage is encountered during Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page b construction, excavation of cut slopes should be halted and the cut slopes should be re-evaluated by Geo Group Northwest, Inc. .Permanent cut and fill slopes at the site should be inclined no steeper than 2H:1 V. Surface runoff should not be allowed to flow uncontrolled over the top of slopes into the excavated area. During wet weather exposed cut slopes should be covered with plastic sheeting during construction to minimize erosion. 5.2.2 Structural Fill All fill material used to achieve design site elevations below the building areas and below non - structurally supported slabs, parking lots, sidewalks, driveways, and patios, should meet the requirements for structural fill. During wet weather conditions, material to be used as structural fill should have the following specifications: 1. Be free draining, granular material containing no more than five (5) percent fines (silt and clay -size particles passing the No. 200 mesh sieve); 2. Be free of organic material and other deleterious substances, such as construction debris and garbage; 3. Have a maximum size of three (3) inches in diameter. All fill material should be placed at or near the optimum moisture content. The optimum moisture content is the water content in soil that enables the soil to be compacted to the highest dry density for a given compaction effort. The majority of the surficial site soils will be moisture -sensitive because they consist of silty SAND and gravelly silty SAND soils. The site soils should be suitable for use as structural fill as long as they are placed near their optimum moisture content. If these soils are too wet they will be very difficult to compact because of their silt content. Alternatively, an imported granular fill material may provide more uniformity and be easier to compact to the required structural fill specification. Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 7 If the on -site soils are to be used as engineered structural fill, it will be necessary to segregate the topsoil and any other organic- or debris -containing soil, because such soils would be unsuitable for use as structural fill. Excavated on -site material that is stockpiled for later use as structural fill should be protected from rainfall or contamination with unsuitable materials by covering it with plastic sheeting until it is used. Structural fill should be placed in thin horizontal lifts not exceeding ten inches in loose thickness. Structural fill under building areas (including foundation and slab areas), should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM Test Designation D-1557-91 (Modified Proctor). Structural fill under driveways, parking lots and sidewalks should be compacted to at least 90 percent maximum dry density, as determined by ASTM Test Designation D-1557-91 (Modified Proctor). Fill placed within 12-inches of finish grade should meet the 95% requirement. We recommend that Geo Group Northwest, Inc., be retained to evaluate the suitability of structural fill material and to monitor the compaction work during construction for quality assurance of the earthwork. 5.3 Spread Footing Foundations The proposed buildings can be supported on conventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native site soils, Based on the findings from our soil investigation at the site, we anticipate that the dense soils are present between 2 feet and 3 feet below ground surface. Some over -excavation and placement of structural fill may be required at foundation locations, dependent upon the proposed finish grades. Individual spread footings may be used for supporting columns and strip footings for bearing walls. Our recommended minimum design criteria for foundations bearing on the dense site soils or on compacted structural fill are as follows: - Allowable bearing pressure, including all dead and live loads Dense native soil = 2,500 psf Compacted structural fill = 2,500 psf Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 8 - Minimum depth to bottom of perimeter footing below adjacent final exterior grade = 18 inches - Minimum depth to bottom of interior footings below top of floor slab = 18 inches - Minimum width of wall footings = 16 inches - Minimum lateral dimension of column footings = 24 inches - Estimated post -construction settlement = 1/4 inch - Estimated post -construction differential settlement; across building width = 1 /4 inch A one-third increase in the above allowable bearing pressures can be used when considering short-term transitory wind or seismic loads. Lateral loads can also be resisted by friction between the foundation and the supporting compacted fill subgrade or by passive earth pressure acting on the buried portions of the foundations. For the latter, the foundations must be poured "neat" against the existing undisturbed soil or be backfilled with a compacted fill meeting the requirements for structural fill. Our recommended parameters are as follows: - Passive Pressure (Lateral Resistance) • 350 pcf equivalent fluid weight for compacted structural fill 350 pcf equivalent fluid weight for native dense soil. - Coefficient of Friction (Friction Factor) • 0.35 for compacted structural fill • 0.35 for native dense soil We recommend that footing drains be placed around all perimeter footings. More specific details of perimeter foundation drains are provided below in Section 5.6 - Footing Drains. Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 9 5.4 Permanent Basement and Conventional Retaining Walls At the time of report preparation finish grades for the proposed residences were undetermined. We understand that a below -grade detention vault will be located at the northwestern corner of the site. We understand that the vault may have conventional retaining walls on the order of 10 to 12 feet in height. The following design recommendations may be used for permanent basement and conventional retaining walls at the project site. Permanent basement walls restrained horizontally on top are considered unyielding and should be designed for a lateral soil pressure under the at -rest condition; while conventional reinforced concrete walls free to rotate on top should be designed for an active lateral soil pressure. Active Earth Pressure Conventional reinforced concrete walls that are designed to yield an amount equal to 0.002 times the wall height, should be designed to resist the lateral earth pressure imposed by an equivalent fluid with a unit weight of- 0 35 pcf for level backfill behind yielding retaining walls • 45 pcf for a 25 percent sloped backfill • 60 pcf for a 50 percent sloped backfill At -Rest Earth Pressure Walls supported horizontally by floor slabs are considered unyielding and should be designed for lateral soil pressure under the at -rest condition. The lateral soil pressure design should have an equivalent fluid pressure of: • 60 pcf for level ground behind permanent unyielding retaining walls • 75 pcf for a 25 percent sloped backfill • 100 pcf for a 50 percent: sloped backfill Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 10 Passive Earth Pressure and Base Friction The available passive earth pressure that can be mobilized to resist lateral forces may be assumed to be equal to 350 pcf equivalent fluid weight in both undisturbed soils and engineered structural backfill. The base friction that can be generated between concrete and undisturbed native soils or engineered structural backfll may be based on an assumed 0.35 friction coefficient. We recommend that a vertical drain mat, Miradrain 6000 or equivalent, be used to facilitate drainage behind permanent concrete basement and conventional retaining walls. We recommend that the drainage mat be installed on the back side of the wall extending from the finish grade down to a footing drain pipe. The wall footing drain pipe should consist of a 4-inch diameter perforated rigid PVC pipe surrounded by a bed of washed gravel and separated from site soils by filter fabric, Mirafi 140N or equivalent. The drain pipe should be tightlined to discharge. BackfilI behind conventional retaining walls should consist of free -draining sand or gravel soils which are compacted in lifts. Backfill in areas adjacent to basement or conventional retaining walls should be compacted with hand held equipment or a hoepack. Heavy compacting machines should not be allowed within a horizontal distance to the wall equivalent to one half the wall height, unless the walls are designed with the added surcharge. 5.5 Slab -on -Grade Floors Loose site soils should be excavated from all slab subgrade areas or compacted to a firm and unyielding condition. Slab -on -grade floors may be constructed on top of medium dense to dense native site soils or on top of compacted structural fill placed on top of the competent site soils. The slab -on -grade floors should not be constructed on top of the loose fills at the site. To avoid moisture build-up on the subgrade, slab -on -grade floors should be placed on a capillary break, which is in turn placed on the prepared subgrade. The capillary break should consist of a minimum of a six (6) inch thick layer of free -draining crushed rock or gravel containing no more than five (5) percent finer than the No. 4 sieve. A vapor barrier, such as a 6-mil plastic membrane, is recommended to be placed over the capillary break beneath the slab to reduce Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 11 water vapor transmission through the slab. Two to four inches of sand may be placed over the barrier membrane for protection during construction. 5.6 Footing Drains We recommend that drains be installed around the perimeter of the foundation footings. The drains should consist of a -four (4) inch minimum diameter perforated rigid drain pipe laid at or near the bottom of the footing with a gradient sufficient to generate flow, as schematically illustrated in Plate 3 - Typical Footing Drain Detail. The drain line should be bedded on, surrounded by, and covered with a free -draining rock, pea gravel, or other free -draining granular material. The drain rock and drain line should be completely surrounded by a geotextile filter fabric, Mirafi 140N or equivalent. Once the drains are installed, the excavation should be backfilled with a compacted fill material. The footing drains should be tightlined to discharge into the storm water collection system. Under no circumstances should roof downspout drain lines be connected to the footing drainage system. All roof downspouts must be separately tightlined to discharge into the storm water collection system. We recommend that sufficient cleanouts be installed at strategic locations to allow for periodic maintenance of the footing drains and downspout tightline systems. 5.7 Pavements Based upon the site plan we understand that a new access roadway and cul-de-sac turnaround will be constructed running east -west near the center of the site. The adequacy of pavements is strictly related to the condition of the underlying subgrade. We recommend that all pavement subgrades be compacted by several passes of a large vibratory drum roller prior to placement of the crushed rock base. Before paving, we recommend that the subgrade be proof -rolled under the supervision of the geotechnical engineer to verify that the subgrade is firm and unyielding at the time of paving. The proof -roll may be performed by driving a fully loaded dump truck over the subgrade areas. If loose or yielding soils are encountered it may be necessary to over - excavate and replace with compacted structural fill in some areas. For firm and unyielding native subgrade soils we recommend the following minimum pavement sections for driveways: Class "B" Asphalt Concrete (AC) 3 inches Crushed Rock Base (3/4-inch minus) 6 inches Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 12 Concrete Pavement b inches Crushed Rock Base (3/4-inch minus) 4 inches In accordance with the Washington State Department of Transportation Construction Manual, transverse cracks will develop in concrete slabs at about 15 foot intervals along the length of slabs and a slab wider than 15 feet may crack longitudinally. To control cracking of the concrete, contraction joints should be installed. Contraction joints are weakened planes which collect the cracking into a controlled joint, creating a maintainable joint in the slab, and preventing random ragged cracks which spread and require expensive maintenance. We recommend that contraction and construction joints be connected with #5 dowel bars, 30 inches long, 18 inches on center. The contraction joints should be placed at maximum 14 foot intervals. 6.0 LE%HTATIONS This report has been prepared for the specific application to this site for the exclusive use of Mr. Cliff Williams of Belmont Homes, Inc. and his authorized representatives. We recommend that this report be included in its entirety in the project contract documents for use by the contractor. Our findings and recommendations stated herein are based on field observations, our experience and judgement. The recommendations are our professional opinion derived in a manner consistent with the level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area and within the budget constraint. No warranty is expressed or implied. In the event the soil conditions are found to vary during site excavation, Geo Group Northwest, Inc, should be notified and the above recommendation should be re-evaluated. 7.0 ADDITIONAL SERVICES We recommend that Geo Group Northwest Inc. be retained to perform a general review of the final design and specifications of the proposed development to verify that the earthwork and foundation recommendations have been properly interpreted and implemented in the design and in the construction documents. We also recommend that Geo Group Northwest Inc. be retained Geo Group Northwest, Inc. March 17, 2005 G-1992 Proposed 33-Lot Residential Development, King County, Washington Page 13 to provide monitoring and testing services for geotechnically-related work during construction. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. We anticipate the following construction monitoring inspections may be necessary: 1. Site clearing and grubbing; 2. Over -excavation and structural fill placement at building foundation locations; 3. Verification of bearing soil conditions for foundations; 4. Structural fill placement and compaction; 5. Slab -on -grade preparation; 6. Subsurface drainage installation; 7. Proof -rolling of pavement subgrade areas. We appreciate this opportunity to have been of service to you on this project. We look forward to working with you as this project progresses. Should you have any questions regarding this report or need additional consultation, please feel free to call us. Sincerely, Geo Group Northwest, Inc. al"� /d(dz�_ Adam Gaston Staff Engineer William Chang, P.E. Principal Geo Group Northwest, Inc. ILLUSTRATIONS G-1992 Geo Group Northwest, Inc. APPENDIX A: TEST PIT LOGS G-1992 E 180TH PL u S-T zsT ST r � ` sE 18157. -�t5 ST S I82ND �¢ S PL ? "'' SE 183RD Q i SS^ 2col ti :.: t 1g34tD� SE PL Lu. t ST �a 183 SE i �--:5 477H. St ^ T- ---- ---- _ _ $E 184TH ate 1 84�THj c' LN PL ' V i----PL SE SE 185iN��, _ I SE 187TI{ 5T ST S n Lu M SE 187TH SEi) ST �o SE4a 187-9 CT $ SE 188TH STD Pt o 1 t a �� 51 SE 189TH ST SE ` gE CT.t SE t 190TTHH a sTk, 5E 190TH ST iagTti �-` � fl PROTECT u"? r m -------6 SE SE 190TH PL S �' � SITE SE 190TN ' } 5 Q ST 190TH PL � 41� ' T:::. 192�lD�'E "� Si SE 4 � Q� t `v' o t i94 1Q SEA co s o� SE 194T}f $t �? v SE o I957H ' ST rs SE 1 b7H 5T SE r y a - Lwu 1 N d� V, aSE SPB 199TH r I o 0 _ZQQ . �°- r:9�. ST 20 TH ST Lu 201ST LLJ ST Iti- j:z " --it i { ST VZCIMTY MAP Group Northwest, Inc. PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT GaoWchnical eVkmmm. GaologFsts, a SW CORNER AT SE 192ND ST. & 102ND AVE. SE Environmental Scientists KING COUNTY, WASHINGTON JOBNO: G-1992 PLATE SCALE: NONE DATE: 3/11/05 MADE: AG CIUM WC 1 400 •fit . 4.. {�'• - - wo Now 3'52 384 384 a� ,B&'o p 3 �,; 394 `, 90 412 , 400 . see 11 a ''I 'E •S \t 4' '.. -ilY S -� _ l r r! z J 554 S132 3e& f I CI1 f 25 1-41 .7 412 Rio 30 ___ i = F, t5 .4 Y I i" t ,� IY4 `- _' ..F - 1•{r0 ) - .; ' 412 356 L 3�6 i 396 -404 TP-5 ;376 j j ITI T4402 332I . k TP-1 i3� {' TP-3336. 98 s Sr 36t r dam, ! 4e Sde Plan based upon preliminary plans provided by Belmont Homes, Inc. _ SITE PLAN LEGEND Grou Nox-�hwest, Inc.PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT ��hn� Engineers, Geologists. & SW CORNER AT SE 192ND ST. & 102ND AVE SE TEST PIT NummER AND APPROXUAATE EmbronimMal Scientists RING COUNTY, WASEIINGTON TP-1 LOCATION SCALE I"=40' DATE 3/11/05 MADE AG CEND WC JOB NO. G-1992 PLATE 2 BACKFILL WITH COMPACTED NATIVE SOIL GEOTEXTILE FILTER FABRIC, M RAFI 140N OR EQUIVALENT FREE DRAINING BACKFILL CONSISTING OF WASHED ROUND ROCK OR CRUSHED ROCK MINIMUM 4 INCH DIAMETER 1 PERFORATED PVC PIPE LEVEL OR WITH POSITIVE GRADIENT TO DISCHARGE 6"to 12" SLAB s FOOTING NOT TO SCALE NOTES: i 1.) Do not replace rigid PVC pipe with flexible corrugated plastic pipe. 2.) Perforated or slotted PVC pipe should be tight jointed and laid with perforations or slots down, with positive gradient to discharge. 3.) Do not connect roof downspout drains into the footing drain lines. TYPICAL FOOTING DRAIN DETAIL Group Northwest, Inc. PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT Geotechnical Engineers, Geologists. s SRC CORNER AT SE 192ND ST. & 102ND AVE. SE EnironRCntalscientists . KING COUNTY, WASHINGTON scALE NONE DATE 3/11/05 1 MADE AG cHKD WC I JOB No. G•1992 I PLATE 3 LEGEND OF SOIL CLASSIFICATION AND PENTRATION TEST UNIFIED SOIL CLASSIFICATION SYSTEM (USCS) MAJOR DIVISION GUP TYPICAL DESCRIPTION SROYMBOL, LABORATORY CLASSIFICATION CRITERIA CLEAN GW WELL GRADED GRAVELS, GRAVEL -SAND Cu = (13601 Ill 0) greater than 4 GRAVELS MIXTURE, LITTLE OR NO FINES DETERMINE CC = (0302 ) I (D10 • OW) between 1 and 3 PERCENTAGES OF GRAVELS 0lttle or no GP POORLY GRADED GRAVELS. AND GRAVEL-SANDGRAVEL AND SAND (More Than Half lines) MIXTURES LITTLE OR NO FINES FROM GRAIN SIZE NOT MEETING ABOVE REQUIREMENTS COARSE- GRAINED SOILS Coarse Grains DISTRIBUTION ATTERBERG LIMITS BELOW Lam Than No.4 Sieve) DIRTY GM SILTY GRAVELS, GRAVEL -SAND -SILT MIXTURES CURVE 'A' LINE. GRAVELS CONTENT P.I. LESS THAN 4 OF FINESor CLAYEY GRAVELS, GRAVEL -SAND -CLAY ATTER13EAG LIMITS ABOVE {with some EXCEEDS 12% fines) GC MIXTURES COARSE GRAINED 'A' LINE SOILS ARE or P.L. MORE THAN 7 CLASSIFIED AS SANDS CLEAN WELL GRADED SANDS, GRAVELLY SANDS, SW FOLLOWS: Cu= D601 D10 ( ) greater then 6 UITLE OR NO FINES Cc = (030=)1(010 " DOD) between 1 and 3 SANDS (More Than Half More Than Half Coarse Grains (little or no POORLY GRADED SANDS, GRAVELLY SANDS, SP <5% Fine Grained; NOT MEETING ABOVE REQUIREMENTS by Weight Larger SmalierTitan No, fines) LITTLE OR NO FINES GW, GP, SW, SP Than No. 200 4 &eve) ATTERBERG LIMITS BELOW Sieve DIRTY SM SILTY SANDS, SANp-SILT MIXTURES 12% Fine Grained; A' LINE SANDS GM, GC, 5M, SC CONTENT OF with P.I. LESS THAN 4 FINES ATTERBERG LIMITS ABOVE (with Some 5 to 12% Fine EXCEEDS 12% lines) Sc CLAYEY SANDS, SAND -CLAY MIXTURES Grained: use dual 'A" LINE symbols with P.I. MORE THAN 7 Liquid Limit INORGANIC SILTS, ROCK FLOUR, SANDY SILTS SILTS <50% ML OF SLIGHT PLASTICITY 60 (Below A-L€ne on Plasticity Chart, FINE-GRAINED Organic) Liquid id Un9t MH INORGANIC S1LT5, MICACEOUS OR 50 SOILS 50% DIATOMACEOUS, FINE SANDY OR SILTY SOIL ;e INORGANIC CLAYS OF LOW PLASTICITY, IXiI 40 LiquCLAYS <i30%mt CL GRAVELLY, SANDY, OR SILTY CLAYS, CLEAN Z (Above A-Une on CLAYS 30 Plasticity Chart, Negligible Organic) Liquid Urnit CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT U ? 50% CLAYS 20 More Than Half by Weight SmolletORGANIC Liquid Limit ORGANIC SILTS AND ORGANIC SILTY CLAYS OF IL 10 Than No.200 SILTS 60% OL LOW PLASTICITY Sieve & CLAYS (BelowA-Ljneon Placticity Chart) Liquid ii%t OH ORGANIC CLAYS OF HIGH PLASTICITY -,' r _ � � —�-- 0 10 20 30 40 60 7Q BO 90 10 11 0 0 LIQUID LIMIT (%) HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS SOIL PARTICLE SIZE GENERAL GUIDANCE OF SOIL F_NGINEEMNG PROPERTIES FROM STANDARD PENETRATION TEST (SPT) U.S- STANDARD SIEVE FRACTION Passing Retained SANDY SOILS SILTY & CLAYEY SOILS Size Sieve {mmj SieveSize (mm) Blow Counts Relative Density Friction Angie Description Bloc, Counts Unconfined Strength Description SILT I CLAY #200 0.075 N % degree N qu, tsf 26W 0-4 D -15 Very Loose < 2 < 025 Very soft FINE #40 0.425 #200 0.075 4-10 15 - 35 26 - 30 Loose 2-4 025.0.50 Soft MEDIUM *10 2 #40 OA25 10.30 35 - 65 28 - 35 Medium Dense 4-8 0.50 - 1.00 Medlum Stiff COARSE #4 4.75 #10 1 2 30 - 50 a 50 65 - 85 85. 100 35 - 42 38 - 46 Dense Very Dense 8. 15 15 - 30 1.00 - 2.00 2.00 - 4.00 Stiff Very Siff GRAVEL FINE 19 04 4.75 a 30 s 4A0 Hard AM— Group Northwest, Inc, ,�. COARSE 76 19 COBBLES 76 mm to 203 rnm BOULDERS ? zo3 rren _ Gectechnical Engineers, Geologists, & EnAmrinrental Scienlats ROCK a 76 mm - FRAGMENTS 13240 NE 20M Street, Suite 12 Bellevue, WA 991105 Phone (425) 649-8757 Fax (425) 649-8758 -PLATE Al- ROCK f >0.76 cubic meter In volume TEST PIT NO. TP-1 LDGGED BY AG TEST PIT DATE: 3/9/05 DEPTH 4. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS 4" thickness forest duff Probe 6-12" S1 20.7 Probe 12" SM Orangish Brown silty SAND with some gravel and cobbles, moist, loose --- ---- 5M ---------------------------------------------------- Tan silty SAND with some gravel and cobbles, moist, dense S2 19.9 5 SM some cementation 53 21.2 Total depth of test pit = 5 feet bgs No groundwater seepage 10 15 TEST PIT NO. TP-2 LOGGED BY AG TEST PIT DATE: 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS 4" thickness forest duff Probe 24" SM Orangisb Brown silty SAND with some gravel and cobbles, charcoal nieces. moist. loose IN S1 15.6 --- ----- ---------------------------------------------------- Probe 3-4" SM Mottled gravelly silty SAND with occasional cobbles, moist, dense S2 15.4 Probe 2-3" 5 SM/ Gray fine silty SAND to sandy SILT with some gravel and occ. ML cobbles, very dense S3 14.3 Total depth of test pit = 6 feet No groundwater seepage 10 15 Group Northwest, Inc, GeaWchnlcaf Englnaers, Geologists. & Errviranrrental Sdawftts TEST PIT LOGS PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192ND ST. & 102ND AVE. SE KING COUNTY, WASHINGTON JOB NO. G-1992 DATE 3/10/05 PLATE A2 TEST PIT NO. TP-3 LOGGED BY AG TEST PIT DATE: 319105 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS SM 12-18" thickness loose forest duff Probe 12-18" --- ----- ---------------------------------------------------- Sl 18.7 Probe 8-10" SM Orangish Brown gravelly/cobbly silty SAND, moist, loose --- ----- SM --------------------------------------------------- Mottled gravelly/cobbly silty SAND, moist to wet, dense S2 17.6 5 SM/ Gray silty SAND to sandy SILT with some gravel, moist to wet, very ML S3 17 Total depth of test pit = 6 feet bgs No groundwater seepage 70 15 TEST PIT NO. LOGGED BY AG TEST PIT DATE: 9PD...A 3/9/05 DEPTH It. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS 6" thickness loose forest duff Probe 24" SM Orangish Brown fine silty SAND with some gravel, cobbles and boulders, moist, loose ---- SI 12.1 SM Tan silty SAND with some gravel, moist, dense Probe 1-3" 5 some cementation and cobbles S2 I3 Total depth of test pit = 6 feet No groundwater seepage 10 75 Group Northwest, Inc. Geolechniaal Engineers, Geologists. & Emkonrrentel Scientists TEST PIT LOGS PROPOSED 33-LOT RESIDENTIAL. DEVELOPMENT SW CORNER AT SE' 192ND ST. & 102ND AVE. SE LING COUNTY, WASH NGTON ,LOB NO. G-1992 DATE 311E/O5 PLATE A3 TEST PIT NO, TP-5 LOGGED BY AG TEST PIT DATE., 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS SM 6-12" thickness loose forest duff Probe 6-18" ----- ------------------ ------------------------------ Orangish Brown silty SAND with some gravel and occ. cob�iles, S1 16.8 SM moist, Ioose .-------------------------------------------------- SM Tan to mottled fine silty SAND with some gravel, moist to wet, dense I S2 12.3 Probe 1-3" 5 SM Brown gravelly/cobbey silty SAND, moist, very dense Total depth of test pit = 6 feet bgs No groundwater seepage 10 15 LOGGED BY AG TEST PIT NO. TP-6 TEST PIT DATE: 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS --- ------ 6-12" thickness Ioose forest duff ---------------------------------------------------- Probe 24" SM Orangish Brown fine silty SAND with some gravel and cobbles Probe 410" moist, loose 51 11.9 SM Tan silty SAND with some gravel and cobbles, moist, dense 5 some cementation I S2 15.3 SM Mottled gravellylcobbly silty SAND, moist, very dense I S3 14.3 SM Brown gravelly silty SAND with occ. cobbles and boulders, moist, very dense 10 S4 I1.3 Total depth of test pit = 11 feet No groundwater seepage 15 Group Northwest, Inc. Geotechnical Engineers. Gep ists, & Environmental Scientists TEST PIT LOGS PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192ND ST. & 102ND AVE. SE KING COUNTY, WASHINGTON JOB NO. G-1992 1 DATE 3/10/05 PLATE A4 TEST PIT NO. TP-7 LOGGED BY AG TEST PIT DATE: 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS SM 6" thickness loose forest duff Probe 12-I8" Orangish Brown silty SAND with some gravel and cobbles, moist, I S1 14.8 Probe 4-10" _ r SM iansc------------------------------------------------ SM Tan to mottled fine silty SAND with some gravel, moist, dense S2 13.8 5 SM Gray gravelly silty SAND with some cobbles, moist, very dense Total depth of test pit = 5 feet bgs No groundwater seepage 10 15 LOGGED BY AG TEST PIT NO. TP-8 TEST PIT DATE: 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS 6-8" thiclrness loose forest duff Probe 10-12" SM Orangisb Brown silty SAND with some gravel, moist, loose S I 17.3 SM Tan silty SAND with some gravel and occ. cobbles, moist, dense Probe <1" SM Gray gravelly fine silty SAND with some cobbles, moist, v. dense 5 S2 14.7 Total depth of test pit = 5 feet No groundwater seepage 10 15 Group Northwest, Inc. Geotechnlcai Engineers, Geologists, & Emimmmital Scientists TEST PIT LOGS PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192ND ST. & 102ND AVE. SE KING COUNTY, WASHINGTON .IOB No. G-1992 I DATE 3/10/05 1 PLATE A5 TEST PIT NO. TP-9 LOGGED BY AG TEST PIT DATE: 3/9105 DEPTH fL USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS) COMMENTS SM 6" thickness loose forest duff Probe 6-12" SM Orangish Brown silty SAND with some gravel, moist, loose Probe 6-16" --- ----- ----------�------�-�------_--------------------------- S1 12.3 SM Tan silty SAND with some gravel, moist, dense g SM Gray gravelly silty SAND with some cobbles, moist, very dense 52 132 Total depth of test pit = 5 feet bgs No groundwater seepage 10 15 TEST PIT NO. TP-10 LOGGED BY AG TEST PIT DATE: 3/9/05 DEPTH ft. USCS SOIL DESCRIPTION SAMPLE No. Water % OTHER TESTS/ COMMENTS 4" thickness loose forest duff Probe 2-8" SM Orangish Brown silty SAND with some gravel and cobbles, moist, Probe 8-16" loose S 1 17.4 --- ---- SM -------------------____------------------------------ Tan silty SAND with some gravel, moist to wet, dense 5 5M/ Gray silty SAND to sandy SILT with some gravel and occ. cobbles S2 17.6 m, and boulders, moist, v. dense S3 14.1 Total depth of test pit = 6 feet No groundwater seepage 10 15 Group Northwest, Inc. Geotechnlcal Engineers. Geologists. & BwlronmerAM Scientists TEST PIT LOGS PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT SW CORNER AT SE 192ND ST. & 102ND AVE. SE KING COUNTY, WASBINGTON ROCKERY DESIGN Talbot Ridge Estates SW Corner at SE 192" ST & 102" AVE SE KING COUNTY, WASHINGTON Project No. G-1992 - Prepared for Mr. Cliff Williams Belmont Homes, Inc. P.O. Box 2401 Kirkland, WA 98083-2401 February 28, 2007 GEO GROUP NORTHWEST, INC. 13240 NE 20'h Street, Suite 10 Bellevue, WA 98005 Phone: (425) 649-8757 Fax: (425) 649-8758 February 28, 2007 G-1992 Talbot Ridge Estates - Rockery Design Page 2 Site Geology As discussed in the referenced geotechnical report, "According to the Geologic Map of the Renton Quadrangle, King County, Washington, by Mullineaux, dated 1965, the surficial geology in the site vicinity is mapped as Ground Moraine Deposits (Qgt). The ground moraine deposits consist of glacial till soils which are generally described as an over -consolidated mixture of sand, silt, and gravel which was deposited during the Pleistocene Fraser Glaciation period 14,000 years ago." Soils Conditions The subsurface investigation conducted for the referenced geotechnical report encountered silty sands with variable amounts of gravel and cobbles in the 10 test pits excavated onsite. The consistency of the site soils was evaluated by probing with a'/z inch hand probe as the test pits were being excavated. As discussed in the referenced report, dense soils were encountered 2.5 feet below the surface in test pits TP-4 and TP-v excavated on the slopes of Lots 10 and 11 respectively near where the rockery will be constructed. Slope Stability Evaluation The slopes onto which the rockery is to be placed average 26% grade with isolated portions of the slope as steep as 30%. GEO Group Northwest, Inc., evaluated all the sites slopes for the referenced report and found no signs of instability in the slopes at the west end of the property where the fill and rockery are to be placed. Site Preparation and General Earthwork The area where the rockery and associated fills are to be placed should be stripped of all vegetation and surficial loose soils. The underlying dense soil surface on the slope should be graded to form horizontal terraces onto which fill will be placed as shown on Plate 3. Construction of the Designed Rockery As discussed in Plate 4 by The Association of Rockery Contractors (ARC), construction of a rockery is a craft that depends largely on skill and experience of the builder. Rockery stability depends on the type of rock used, contact area between rocks, and placement of rocks, all of which cannot be accounted for in an engineered design. The rockery should be constructed in accordance with ARC standards. A copy of the ARC Standards is attached to this report in Appendix A. GEO Group Northwest, Inc. February 28, 2007 G-1992 Talbot Ridge Estates - Rockery Design Page 3 Implementation of the Tensar Geogrid Design(or equivalent) given on Plate 3 will provide a set of guidelines expected to yield a stable finished product as demonstrated by the best practices in the field. Rockery design requirements were developed in accordance with Tensar Design Chart and Keystone Retaining Wall Design program parameters, with a minimum factor of safety of 2.00 calculated for the designed wall. In implementing the Tensar design the following statements may clarify the design and aid in construction: • The base of the rockery as shown on Plate 3 should be composed of dense to very dense soils to be confirmed by the geotechnical engineer before placement of the first rocks in the keyway. • Rocks or should be placed to maximize surface area contact as illustrated on the Associated Rockery Standards (ARC) presented on Plate 4. • Rockery construction and compacted fill placement should take place simultaneously to insure that the proper 1 Horizontal:6Vertical batter of the face of the rockery can be constructed without causing the rockery to collapse uphill. • Geogrid lengths given on Plate 3 should be measured from the -back of the rockery wall and extend into the fill on a level plane, The geogrids should be pulled tight and anchored down before being covered with fill. • Alternative geotextile products may be used in place of the Tensar product provided long term tensile strength properties are equal or better than those specified. • Wall height is measured as the total height of the rockery less the required keyway embedment. For example a rockery or 8 foot wall height would have a total height of 9 feet of rock. • Alterations to the expected rockery placement (Proposed Site Plan, Plate 2) are allowed as long as they comply with the specifications of this report and are confirmed by GEO Group Northwest, Inc. Structural Fill Placement and Material Fill placement will be required behind the rockery to bring the existing grade up to the proposed grade. Native fill should be placed in successive horizontal lifts of loose soil not to exceed 1 foot thick with each successive lift compacted individually, As discussed in section 5.2.2 of the referenced geotechnical report, ustructural fills placed below GEO Group Northwest, Inc. February 28, 2007 G-1992 Talbot Ridge Estates - Rockery Design Page 4 building areas and below non -structurally supported slabs, parking lots, sidewalks, driveways, patios or other structures should be compacted to a minimum of 95% of the Modified Proctor standard (ASTM D1557)." If a footing is to be supported on structural fill the structural fill should extend out beyond the footings at a 1 HAV (Horizontal: Vertical) grade. So for 6 feet of fill placed below footings the structural fill compacted to minimum 95% should extend a minimum 6 feet beyond the inside and outside edges of the footings. Fills placed behind the rockery and outside the areas discussed above should be compacted to a minimum 90% of the modified Proctor Standard. The excavated onsite silty sands may be suitable as structural fill if placed fills are free of roots and organic material and approved by the geotechnical engineer. The majority of the site soils are moisture sensitive because of their silt content. The site soils should be suitable for use as structural fill as long as they are placed near their optimum moisture content. During wet weather or under wet conditions we recommend the use of a free draining granular material with no greater than 5% passing the No. 200 sieve (measured on that portion which passes the 3/4 inch sieve). Native soils stockpiled onsite for use as structural fill should be covered with plastic sheeting to prevent over saturation of the soils. Construction Monitoring We recommend that GEO Group Northwest, Inc., be retained to perform a review of the final design and specifications of the project in order to verify that our geotechnical recommendations have been properly interpreted and incorporated into the construction documents, and that the finalized layout of the project is appropriate. This is to confirm compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. The geotechnical engineer should be retained to perform construction monitoring inspections consisting of the following: 1. Confirm proper rock selection; 2. Full-time inspection of all excavations; 3. Verify keyway depth (D) and inclination; 4. Inspect drainage installation including drain line and filter layer(B); 5. Verify rockery construction according to the specifications of this report; 6. Verify fill compaction as specified in this report; 7. Verify proper length and placement of geogrids. GEO Group Northwest: Inc. February 28, 2007 G-1992 Talbot Ridge Estates - Rockery Design Page 5 Limitations This report has been prepared for the specific application to this project for exclusive use by Mr. Cliff Williams and Belmont Homes Inc. Our findings and recommendations stated herein are based on field observation, our experience, and our judgement. The recommendations are our professional opinion derived in a manner consistent with the level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area and within the budget constraint. No warranty is expressed or implied. In the event the soil conditions vary from those described herein, or construction plans change, GEO Group Northwest, Inc., should be notified and the recommendations herein re-evaluated. We appreciate the opportunity to perform this geotechnical engineering study and look forward to working with you in the construction phase. If you have any questions about this report, or if we can be of further assistance, please call (425) 649-8757. Sincerely, GEO GROUP NORTHWEST, INC. Andy Wade Geologist �2A4�� e__4 William Chang, P. E. Principal Attachments: Plate 1 -Vicinity Map Plate 2 - Proposed Site Plan Plate 3 - Tensar Geogrid Design Plate 4 -ARC Typical Rockery Details Appendix A - ARC Standards GEO Group Northwest, Inc. ST t1 CD 181ST ST S� 181$1 � ST SE Q 182ND 45TH -PL x �' SE j�RD I Co to �._ 1 SE 5:� ` _ SE 184TH a, PL LN SE 185T vd t/) "� ^ Ian SE I87Ty ST ST S 1�� o -, a S C1. + € vt"i ` SE IBT1i rc a SE I 5T r.o SE( + 18TM CT :.�SE 186TH ST' 0 51ST.- I W o � ps-5, SE 189se TH ST €= H ; SE 199TH ' ST �� � SF 190TN ST PCD � PROJECT SE o SE 190TH PL vwir m' :. SE 190TH j .. SZTF + ST 190TH PL � s 194 ,T... I92ND �m ST SE + s ; � ;o cv a7 + �4 fat p 5FCO SE 194711 ST �{ SE I95rH ST SE A 5TH ST $E S 1 u, :. ¢ Y ySE '�yi � i-A:iF`+ .49l 1 f k5s'. Q ST TH ST CL aya cn o+� SE5 ti € yujIn i= N 2015T r c1 0 a �_� ST VICINITY MAP Group Northwest, Inc. PROPOSED 33-LOT RESIDENTIAL DEVELOPMENT Geatechnical Englneers, Geologists, & SW CORNER AT SE 192ND ST. & 102ND AVE. SE Environmental Scientists KING COUNTY, WASHINGTON SCALE: NONE DATE: 3/11/05 MADE: AG CHKD: WC JOB NO: G-1992 PLATE 1 February 28, 2007 Mr. Cliff Williams Belmont Homes, Inc. P.O. Box 2401 Kirkland, Washington 98083-2401 Subject: Rockery Design Talbot Ridge Estates SW Corner at SE 192nd ST & 102nd AVE SE King County, Washington Project No. G - 1992 Ref: GEO Group Northwest, Inc., Geotechnical Engineering Study, Proposed 33-Lot Residential Development, SW Corner at SE 192nd ST. & 102Nb AVE. SE, King County, Washington., dated March 17, 2005. Dear Mr. Williams: This rockery design presents our recommendations for construction of the proposed rockery system in the landscaping area of the subject site. The location of the subject development is illustrated on the Vicinity Map, Plate 1. Surface Conditions The eastern two thirds of the subject parcel slopes down gently to the west from 102nd Avenue SE. The western third of the parcel slopes down to the west with moderate slopes averaging 26% grade. Grading associated with the proposed development will terrace the site to create level building pads. Proposed Rockery A rockery is to be constructed on the west end of Lots 9, 10, and 11 (shown on Proposed Site Plan, Plate 2) in order to expand the level area at the top of the slope increasing the usable area of the lot. We understand fills are intended to be placed behind the constructed rockery to raise the ground surface to the intended permanent grade. Based on your fax and our conversations with you, we understand that a maximum 8 foot tall rockery is planned to face the westernmost edge of the fill. E il SCHEMATIC ONLY (NOT TO SCALE) 100 psf Surcharge .41 oil 7j�n.�; M v 4 H` � ryG l �a �• ;`. IIII =1111 IIII= - IIII—lIII— . Non -woven Geotextile Fabric - Mirafi 140N, or IIII = —F Crushed Drain Rock Keyway (D) IIII 4" O.D. Rigid PVC Perforated Drain Pipe Geogrid Length — —� Tensar UX1500 may be substituted for Height shown is from the top of grade to UX1400 to simplify construction the top of wall. Design heights include 2` embedment of walls 8 feet and taller, with Design Parameters: Phi = 34 degrees T embedment of walls less than 8 feet tall. Ganuna = 130 pef Cohession = 0 TENSAR GEOGRID SCHEDULE FOR ROCKERY RETAINING WALLS WALL TENSAR GEOGRID GEOGRID HEIGHT (H) GEOGRID GEOGRID LENGTH (L) HEIGHT (H) (FT) TYPE LAYER (FT) (FT) 4 UX1400 6 UX1400 8 UX1500SB UX1500SB UX1500SB 10 UX1400 UX1400 Group Northwest, Inc. Geotechnical R4neers, Geoivgisls, & Errvlronrrental Scientists 1 4.0 1.50 1 4.0 1.50 2 4,0 4.00 1 5.5 2.67 2 5.5 6.00 1 7.0 2.00 2 7.0 5.00 4 7.0 8.00 TALBOT RIDGE ESTATES TENSAR GEOGRED DESIGN ROCKERY FACED FILL )JECT NO.: DATE: PLATE: G-1992 1 2/22/2007 1 3 TOT TO SCALE Rock WaH Section • ilodclaelt � 3a a r�lt and � iargai� an the slab A i� xlafl is � p'eatedirlre sya�t[ t the er�rNrerinlg and arm pmacae� as aln � loot. * witch by tts Arne bms. Sim ww d ire two WWAM wrote doWnuf n*uetior4 ll.hi trot a tbeukrAd or smakaw d aramm is the saran a tainioamd caumab rmk* ng • 71a dopm d resteaAm addowed is dep ender an the sba of t w MM4 'tt" is. t o tom.arvaNK wava raipfrt of tiaammil 6milig 9M8bluahll9L Til* kMW*A mdr, the aalmie an d IN, WE* Wd shartw Iba. 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Geolachnical Engineers, Geologlsts, & Environmmntal Scien6sls DATE 2/22/2007 MADE AJW CHKD WC -TAB bM dmmmim aF*0Mdoalrorrid m4wbdbWJtUwmdathim -=a aril fay fn povba mm"m mac. mikg aAaariel-" be mae&bmb== uwwwombepbuldsmillimm coubim is joy t 1a VRWCW or , IN 1, 11 w pewibW aidiii awk ah*W beer an lira aF ttiaalsmcks ba ww 1L wo gaoii � a • AN rm* %aft mast 4 tee k batglad .rlttouiid be canska fed co baSS Edina iftZQL orab 'r0f t0L Spa AppMWMala 1Nnil t- br.- ' 1 Man W - 200 12 - nr 2 Yala 200 - 700 Is -or ' 3 tree 7W - 2WO 28 - ar 4 mm a= - 40M as - 41• S MOR Am - mw 42 - 54• San ti:m - am 54 - G(r RWBM= Lac* *MYVNW*kkdy an km *An sk maim of each mqm abm lea.ti+leu W 1. isea. r� 4r-+t of cieart � 10 ��f]mirrr�t . t! iadt ararwr . apQlroriad hY t�ra 3 � t = � �edpsitwatggprapadartr®�tlial. Ul A-lumbldlim Nsfi e ml 09arirrp* - 44uh mitinrtardkmmW,,pmbmkdar eiaatedj*d plastic ADS p o kdld% tit a l godw&b ds,<taorlga rmdarawrlmitltaiiwuttbriretlnq TYPICAL ROCKERY DETAIL BELMONT HOMES - TALBOT RIDGE ESTATES SW CORNER AT SE 192ND ST & 102ND AVE SE KING COUNTY, WASHINGTON JOB NO. G - 1992 1 PLATE 4 APPENDIX A ARC GUIDELINES Rockery Contractors ,Standard Rock Wall Construction Guidelines P.J. Box 1794 M Woodinville, Washington 98072 Assogiatian Representatives (425) 4g:' 3456 or (425) 481-7222 Contents 1.01 Introduction:........................................................................................---................................... .................1 1.01.1 Historical Background...............................................................................................1 1.01.2 Goal.............................................................................................................................1 2.01 Materials: ................................................................. ....... . .............................................................................. 1 2.01.1 Rock Quality ...........................................................................................................1 2.01.2 Frequency of Testing ...........................................................................................2 2.01.3 Rock Density.............................................................................................................2 2.01.4 Submittals...................................................................................................................2 3.01 Rock Wall Construction: ....................................................................................................... ....................... 2 3.01.1 General................................................................................................................2 3.01.2 Geotechnical Engineer.............................................................................................3 3.01.3 Responsibility.............................................................................................................3 3.01.4 Workmanship..............................................................................................................3 3.01.5 Changes to Finished Product..................................................................................3 3.01.6 Slopes ..................... .........•1-1--.•---................................................................................3 3.01.7 Monitoring..................................................................................................................4 3.01.E Fill Compaction................................................................................j.........................4 3.01.9 Fill Construction and Reinforcement......................................................................4 3.01.10 Rock Wall Keyway...................................................................................................5 3,01,11 Keyway Drainage....................................................................:...............................5 3.01.12 Rock Wall Thickness...............................................................................................5 3.01.13 Rock Selection.........................................................................................................6 3.01.14 Rock Placement.......................................................................................................6 3.01.15 Face Inclination.......................................................................................................6 3.01.16 Voids.......................................................... ...........................................................6 3.01.17 Drain Rock Layer ......................................................................................................6 3.01,18 Surface Drainage.....................................................................................................7 Post Construction Guideline Figure A.................................................................................................................8 TYPICAL DETAIL Native Cut, Any Height Over 4 Feet.............................................................................. .9 TYPICAL DETAIL Overbuild Fill Construction, Rock Wall less than 8 Feet in Height..............................10 TYPICAL DETAIL Geogrid Reinforced Fill Construction., Rock Wall 8 Feet or More in Height ...............11 ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES 1.01 Introduction: 1.01.1 These standard rock wall construction guidelines have been developed in an Historical effort to provide a more stringent degree of control on materials and construction Background methodology in the Pacific. Northwest. They have been assembled from numerous other standards presently in use in the area, from expertise provided by local geotechnical engineers, and from the wide experience of the members of the Associated Rockery Contractors (ARC). 1.01.2 The primary goals of this document are to standardize the methods of construc- Goal tion for rock walls over four feet in height, and to provide a means of verifying the quality of materials used in construction and the workmanship employed in construction. This standard has also been developed in a manner that makes it, to the best of ARC's knowledge, more stringent than the other standards presently in use by local municipalities. 2.01.- Materials: 2.01.1 All rock shall be sound, angular ledge rock that is resistant to weatheriiag. The Rock Quality longest dimension of any individual rock should not exceed three times its shortest dimension. Acceptability of rock will be determined by laboratory tests as hereinafter specified, geologic examination and historical usage records. All rock delivered to and incorporated in the project shall meet the following minimum specifications: a. Absorption ASTM C 127 AASHTO T-85 b. Accelerated Expansion (15 days) CRD-C-1d8 *1, *2 c. Soundness (MsSO4 at 5 cycles) ASTM C88 CRD-C-137 d. Unconfined Compressive Strength ASTM 13,2938 5 e. Bulk Specific Gravity (155pef) ASTM C 127 AASHTO T-85 Not more than 2.0% for igneous and metamorphic rock types and 3.0% for sedimentary rock types. Not more thaft 15% breakdown. Not greater than .5%a loss. Intact strength of 6,000 psi, or greater. Greater than 2.48 * 1. The test sample will be prepared and tested in accordance with Corps of Engineers Testing procedure CRD-C-148, "Method of Testing Stone for Expansive Breakdown on Soaking in Ethylene Glycol.". *2. Accelerated expansion tests should also include -analyses of the fractures and veins found in the rock. 12/2192 PA[sP 7 ARC STANDARD ROCKERY: CONSTRUfTION GUIDELINES 2.01.2 Quarry sources shall begin a testing program when either becoming a supplier or Frequency when a new area of the source pit is opened. The tests described in Section of Testing 2..01.1 shall be performed for every four thousand (4000) tons for the first twelve thousand (12,000) tons of wall rock *supplied to establish that specific rock source. The tests shall then be performed once a year; every 40,000 tons, or at an apparent change in material. If problems with a specific area in a pit or with a particular material are encountered, the initial testing cycle shall be restarted. 2.01.3 - Recognizing that numerous sources of rock exist, and that the nature of rock will Rock vary not only between sources but also within each source, the density of the Density rock shall be equal to, or greater than, -one hundred fifty-five (155) pef. Typi- cally, rocks used for rock wall construction shall be sized approximately as follows: ' Rock Size Rock Weight Average Dimension One man 50-200 pounds 12 to 18 inches Two man 200-700 pounds 18 to 28 inches Three roan 700-2000 pounds 28 to 36 inches Four man 2000-4000 pounds 36 to 48 inches Five Man 4000-6000 pounds ­48 to 54 inches Six Man 6000-8000 pounds 54 to 60 inches In rock walls eight feet and over in height, it should not be possible to move the large sized rocks (four to six -man size) with a pry bar. If these rocks can be moved, the rock wall should not be considered capable of restraining any significant lateral load. However, it is both practical and even desirable that smaller rocks, particularly those used for "chinking" purposes, can be moved with a pry bar to achieve the "best fit". 2.01.4 The rock source shall present current geologic and test data for the minimum Submittals guidelines'described in Section 2.01.1 on request by either the rock wall contrac- tor, the owner, or the applicable agency. 3.01 Rock Wall Construction: 3.01.1 Rock wall construction is a craft and depends largely on the skill and experience General of the builder. A rock wall is a protective system which helps to retard the weathering and erosion process acting on an exposed cut or fill soil face. While by its nature (the mass, size and shape of the rocks) it will provide some undeter- mined degree of retention, it is not a designed or engineered system in the sense A reinforced concrete retaining wall would be considered designed or engineered. The degree of retention achieved is dependant on the size of rock used; that is, the "mass" or weight, and the height of the rock wall being constructed. The larger the rock, the more competent the rock wall. To accomplish an appropriate 1 212J92 PAGE,2 ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES degree of competency, all rock wails in excess of four feet in height should be built on a "mass" basis, i.e, by .the ton. , To provide a competent and.adequate rock wall structure, all rock walls con- structed in front of either cuts or fills eight feet and over in height should be bid and constructed in accordance with these standard guidelines and the geotechnical engineer's supplemental recommendations. Both the standard guidelines and the supplemental geotechnical recommendations should be pro- vided to prospective bidders before bidding and- the start of construction. 3.01.2 The geotechnical engineer retained to provide necessary supplemental rock wall Geotechnical construction guidelines shall be a practicing geotechnical/civil engineer licensed Engineer as a professional civil engineer in the State of 'Washington who has had at least four years of professional employment as a geotechnical engineer in responsible charge, including experience with fill construction and stability and rock wall construction. The geotechnical engineer should be hired either by the rock wall contractor or the owner. 3.01.3 The ultimate responsibility for standard rock wall construction should remain Responsibility with the rock wall builder. However, rock walls protecting moderate to thick fills, with steep sloping surfaces above or below them, with multiple'steps, with foundation or other loads affecting them, protecting sandy or gravelly soils subject to raivelling, with seepage or wet conditions, or that are eight feet or more in height, all represent special design conditions and require consultation and/or advice from qualified experts. 3.01.4 All workmanship is guaranteed by the rock wall contractor and all materials are Workmanship guaranteed by the supplying quarry for a period of six years from the date of completion of erection, providing no modification or changes to 'the conditions existing at the time of completiorr'are made. 3.01.5 Such changes include, but are not necessarily limited to, temporary excavation of Changes -to ditches or trenches for any utility within a distance of less than five feet from the Finished back of the top of the rock wall; excavation made either within a distance equal Product to at least two thirds of the free-standing wall height in front of the toe of a rock wall, or that will penetrate an imaginary line extended at a 1H:I V (Horizontal: Vertical) slope from the front edge of the rock wall toe (see Figure A); removal of.,any material from the subgrade in front of the wall, excavation of material from any location behind the rock wall within a distance at least equal to the rock wall's height, the addition of any surcharge or other loads within a similar distance of the top of the rock wall, or surface or subsurface water forced, di- rected, or otherwise caused to flow behind the rock wail in any quantity. 3.01.6 Slopes above rock walls should be i'ept as flat as possible, but should not exceed Slopes 2H:1V unless the rock wall is designed specifically to provide some restraint to the load imposed by the slope. Any slope existing above a completed rock wall should be covered with vegetation by the owner to help reduce the potential for surface water flow induced erosion. It should consist of a deep rooted, rapid growth vegetative mat, will typically be placed by"hydroseeding and covered with a mulch. It is often useful to overlay the seed and mulch with either pegged ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES in -place jute matting, or some other form of approved geotextile, to help main- tain the seed in -place until the root mat has an opportunity to germinate and take hold. 3.01.7 All rock walls constructed against cuts or fills eight feet and over in height shall Monitoring be periodically, monitored during construction by the geotechnical engineer to verify that the nature and quality of the materials being used are appropriate, that the construction procedures are appropriate, and that the rock wall is being constructed in a generally professional manner and in accordance with this ARC guideline and any supplemental recommendations. On completion of the rock wall, the geotechnical engineer should submit to the client, the rock wall contractor, and to the appropriate municipality, copies of his rock wall examination reports along with a final report,summarizing rock wall construction. 3.01.8 Where rock walls are constructed in front of a fill, it is imperative that the owner Fill ensure the fill be placed and compacted in a manner that will provide• a.compe- Compaction tent fill mass_ To achieve this goal, all fins should consist of relatively clean, organic and debris free granular materials with a maximum size of four inches. Ideally, but particularly if placement and compaction is to take place during the wet season, they should contain no more than seven percent fines (silt and clay sized particles) passing the number 200 mesh sieve. All fills should be placed in thin lifts not exceeding ten (10) inches in loose thickness. Each lift should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM Test Method D-1557-78 (Modified Proc- tor), before any additional fill is placed and compacted. In -place density tests should be performed at random locations within each lift of the fill to verify that this degree of compaction is being achieved. 3.01.9 There are two methods of constructing a fill. The first, which typically applies to Fill rock walls of less than eight feet in height, is to overbuild and then cut back the Construction fill. The second, which applies to all rock walls eight feet and over in height, is Reinforcement to construct the fill using a geogrid or geotextile reinforcement. Overbuilding the fill allows for satisfactory compaction of the fill mass out beyond the location of the fill face to be protected. Overbuilding also allows the earthwork contractor to use larger and more effective compaction equipment in his compactive efforts, thereby typically achieving a more competent fill mass. Cutting back into the well compacted fill also typically results in construction of a competent near vertical fill face against which to build the rock wall. For the higher rock walls the use of a.geogrid or geotextile fabric to help rein- force the fill results in construction of a more stable fill face against which to construct the rock.wall. This form of construction leads to a longer lasting and more stable rock -wall and helps reduce the risk of significant long terns mainte- nance. `. 1 212l92 PAGE 4 ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES This latter form of construction requires a design by the gootechnical engineer for each specific case. The vertical spacing of the reinforcement, the specific type of reinforcement and the distance to which it must extend back into the fill, the amount of lapping and the construction sequence must be detennined'on a case by case basis. 3.01.10 The first step in rock wall construction, after general excavation, is to construct a Bock Wall keyway in which to build the rock wall. The keyway shall comprise a shallow Keyway trench of at least twelve (12) inches in depth, extending for the full length of the rock wall. The keyway subgrade should be slightly inclined back towards the face being protected. It is typically dug as wide as the rock wall (including the width of the rock filter layer). If the condition of the cut face is of -concern, the keyway should be constnicted in sections of manageable length, that is, of a, length that can be constructed in one shift or one day's work. The competency of the keyway subgrade to support the rock wall small be veri- fied by probing with a small diameter steel rod_ The rod shall have a diameter of between three -eighths and one-half inch, and shall be pushed into the subgrade in a smooth unaided manner under the body weight of the prober only. Penetration of up to six inches, with some difficulty, shall indicate a "competent" keyway subgrade unless other factors in the geotechnical engineer's ppinion shall indi- cate otherwise. Penetration in excess of six incites, with ease, shall indicate a "soft" subgrade and one that could require treatment. Shallow soft areas of the subgrade can be "firmed up" by tamping a layer of coarse quarry spalis into the subgrade. 3.01.11 Upon completion of keyway excavation, a shallow ditch or trench, approximately Keyway twelve (12) inches wide and deep, should be dug along the rear edge of the key Drainage way. A minimum four -inch diameter perforated or slotted rigid ADS drain pipe, or equivalent, approved by an engineer, should, be placed in this shallow trench and should be bedded on and surrounded by a free -draining crushed rock. Burial of the drain pipe in this shallow trench provides protection to the pipe. and helps ` prevent it from being inadvertently crushed by pieces of the rock wall rock. This drain pipe should be installed with sufficient gradient to initiate flow, and the outfall should be connected to a positive and permanent discharge. Positive and permanent drainage should be considered to mean an existing or to be installed storm drain system, a swale, ditch or other form of surface water flow collection system, a detention or retention pond, or other stable native site feature or previously installed collection system. 3.01.12 The individual rock wall thickness should be equal to the thickness -of the recom- Rock Nall mended size of rock plus the thickness of the drain rock layer. This thickness, Thickness which will be determined on a case by case basis, will be dependant on the specific rock sizes recommended for each individual rock wall. For example, if four -man rock is used the rock wail thickness will be approximately five feet_ I217A2 parF 5 ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES 101.13 The contractor should have sufficient space available so that he can select from Rock among a number of stockpiled rocks for each space in the rock wall to be filled. Selection Rocks which have shapes which do not match the spaces offered by the previous course of rock should be placed elsewhere to obtain a better fit. Rock should be of a generally cubical, tabular or rectangular shape and selected in accordance with Section 2.01.3. Any rocks of basically rounded or tetrahedral form should be rejected or used for filling large void spaces. 3.01.14 The first course of rock should be placed on firm unyielding soil. There should Rock be full contact between the rock and soil, which may require shaping of the Placement ground surface or slamming or dropping the rocks into place so that the soil foundation conforms to the rock face bearing on it. The bottom of the first course of rock should be a minimum of twelve (12) inches below the lowest adjacent site grade. As the rock wall is constructed, the rocks should be placed so that there are no continuous joint -planes in either the vertical or lateral direction. Wherever possible, each rock should bear on at least two rocks below it. Rocks should be placed so that there is some bearing between flat rock faces rather than on joints. Joints between courses (the top surface of rock), should slope back towards the cut face and away from the face of the rock wall. Smaller rocks (one to two -man size) are often used to create an aesthetically pleasing "top edge" to a rock wall. This is an acceptable practice provided none of the events described in Section 3.01.5 occur, and that people are prevented from climbing or walking on the finished wall. This is the owner's responsibility. 3.01.15 The face of the rock wall should be inclined at a gradient of about 1 H:SV back Face towards the face being protected. The inclination should not be constructed Inclination flatter than 1H:4V. 3.01.16 Because of the nature of the product used to construct a rock wall, it is virtually Voids impossible to avoid creating void spaces between individual rocks. However, it should be. recognized that voids do not necessarily constitute a problem in rock wall construction. As the size of rock used to build a rock wall increases, i.e. to six -man size, the void spaces between individual rocks should be expected to be larger. Where voids of greater than six inches in dimension exist in the face of a rock wall they should be visually examined to determine if contact between the rocks exists within the thickness of the rock. wall. If contact does exist, no further action is required. However, if there is no rock contact within the rock wall thickness the void should be "chinked" with a smaller piece of rock. . 3.01.17 In order to provide some degree of drainage control behind the rock wall, and as Drain Rock a.means of helping to prevent loss of soil through the face of the rock wall, a Layer rock drainage filter shall be installed between the rear face of the rock wall and the soil face being protected. This drain rock layer should be at least twelve (12) -' - inches thick; and for rock walls eight feet in height or higher, it should be at t 2/2/92 PAGE 6 ARC STANDARD ROCKERY CONSTRUCTION GUIDEUNES least eighteen (IS) inches thick. It should be composed of 4 to 2-inch sized crushed rock quarry spells, crushed concrete, or other material approved by the geotechnical engineer. If a random wall rock extends back to the exposed soil face, it is not necessary that the filter rock layer extend between it and the soil face. Depending on soil type and potential water seepage, a geotextile fabric may or may not be required. This can be determined on a case by case basis by the geotechnical engineer during design and prior to bidding. 3.01.18 It is the owner's responsibility to intercept surface drainage from above the rock Surface wall and direct it away from the rock wail to a positive and permanent discharge Drainage well below and beyond -the toe of the rock wall. Use of other drainage control measures should be determined on a case -by -case basis by the geotechnical engineer -prior to bidding on the project. 1212(92 PAGE 7 ARC STANDARD ROCKERY CONSTRUCTION GUIDELINES Post Construction Guidiine Schematic Ont - Not to Scale 011 1 H:1 V H Height of rock wall. 5FT No temporary excavation or trenching. 2/3 H No temporary'excavation or trenching. Hi No permanent removal of subgrade allowed. H-' No excavation of material or any surcharge allowed. - I H: I V No excavation below allowed_ 2H:1 V Maximum finished grade or permanent excavation. 92f2/92 PAGF R W Lo LEGEND Schematic Only - Not to Scale a:�o' Crushed rock or other apporved material ranging between 4 to 2 inches in sire and free of organics, with less than 5 percent fines �? a: a (sik and clay size particles passing the No. 200 mesh sieve). Structural fill overbuild, compacted to at least 95% of maximum dry density as determined by ASTM Test Method D-1558-78 (Modified Proctor). Compacted structural fill consisting of free -draining, organic -free material with a maximum size of 4 inches, Should contain no more than 7 percent fines (described above), compacted to at least 95 percent of AS`fM D-1557-78 maximum dry density, Undisturbed firm Native soil 0 Perfarated or slotled drain pipe.wilh 4 inch minimum diameter bedded on and surrounded by' brushed rock filter material, described above. ® Designates size of rock required, i.e. 4 man. NOTES • All fill should be placed in thin lifts not exceeding 10 inches in loose thickness. Each layer should be compacted to no less than 95 percent of maximum dry density, as determined by ASTM D-1557-78 (Modified Proctor). • Thickness of coshed filter rock layer, B, should be no less than 12 inches. • Depth of burial of basal layer of rock, D, should be no less than 12 inches. • Height of rock wait, H, should not exceed feet. • Lateral extent of fill overbuild, l-o should be no less than H feet. • Minimum width of keyway excavation. W. should be equal to the thickness of the basal rock (as determined �y geolechnical engineers design) plus K TYPICAL DETAIL ' -- - ROCK WALL LESS ESS THAN 8 FEETOIN tHEIGHT plate Schematic Dnly - Not to Scale H �� �f G A 4 Z z !� � •� ,gyp •,^, - -- b LR ~i LEGEND Crushed rock or crushed concrete drain rock material Qranging between 4 and 2 inches in size and free ofp: organics. wlth less than 5 percent fines Wit and clay 61ze pi►ticles passing the No. PRO rash aieve). Compacted stnieWral Ul consisting of free -draining material with a mlaximurn size of 4 inches, Should contain rw more Ihan 7 percent tines (described above), compacted to at least 96 pi ircenf of Modified Proctor rna;dmum dry danslty. Undislurbed firm Native soil. Geogrid reinforcement approved by geotechncal engineer. Perfora104 or slotted, smooth -walled, plastic drain pipe with 4 Inches rnipirnum diameter bedded on and 0 surrounded by crushed rock filter material, described above, Designates sire or rock requlriod, i.e. 5- min. NOTES - AN fief should bQ placed in tWn lilts not exceeding 10 inches in loose thiokneas. Each layer should be cornpaclad to no less than 96 percent of rnaxknum dry density, as tfetsrmined by Modified Proctor. • "engirt of reinforcing geogrid, LB shall be feet. G"grid re'nfor cement iayer spacing, Z, anal be - feel as cletcrrnined by the geotechnical engines f. • Height of rock wail, H, should not exceed - font. - Thickness of crusned drain rock layer, bd, shouid bs no less than 12 inches, • Depth of burial of basal layer of rock. D. should be no leis than 12 inches, • Minimum width of keyway excaEvation, b, should be equal to the thkCicr M of the bassi rock (as ftlermined by geoiechnical engineer) plus bd. TYPICAL ROCKERY DETAIL Plate ARC9=M==-GEOGRID REINFORCED FILL CONSTRUCTION ROCK WALL A'FEET OA MORE MY HEJQMT C a Page 1 of 1 CORE - Rob Stevens From: Comstock, Patt [Patt.Comstock@METROKC.GOV] Sent: Thursday, January 18, 2007 10:55 AM To: CORE - Rob Stevens Subject: RE: Talbot Ridge Estates L05P0007 Hi Rob, You stated it correctly. Metro does not have service at this location, nor do we foresee any in the future_ We will not need to review your plans and will not be requesting any transit related improvements. Our closest service runs north/south on 108th Ave SE; Metro Rts. 161 and 169. Thank you for contacting me. — Patt Patt Comstock - Transportation Planner - Transit Route Facilities - King County Metro - patt.comstock@metrokc.gov - (206) 684-1523 From: rhs@coredesigninc.com [mailto:rhs@coredesigninc.eom] Sent: Thursday, January 18, 2007 10:22 AM To: Comstock, Patt Cc: grb@coredesigninc.eom Subject: Talbot Ridge Estates L05P0007 Patt, Talbot Ridge Estates is located at the SW corner of 192"d Street and 102"d Avenue SE intersection. As you had mentioned in your voice message, there are no current or future planned bus routes on these roads, therefore Metro Service Planning will not need to review the street tree plan. Please confirm by replying to this message. Thanks, Robert H. Stevens, P.E. Principal Core Design, Inc. 14711 - NE 29th Place, Suite 101 Bellevue WA 98007 Tel: 425.885.7877 Fax: 425.995.7963 www.coredesigLninc.com 1/18/07 7. OTHER PERMITS: A permit from Soos Creek Water and Sewer District is required for the water and sewer construction. 8. CSWPPP ANALYSIS AND DESIGN: Design of the ESC plan was completed in conformance with Core Requirement 45 per the 2005 KCSWDM. Compliance with the 9 minimum requirements is summarized below. Clearing Limits: Clearing limits have been delineated on sheet C2.01 of the civil plans. The clearing limits extend only to those areas that will be disturbed during construction of the subject project. 2. Cover Measures: The Erosion/Sedimentation Control Notes listed on sheet C2.31 of the civil plans specify specific times at which temporary and permanent cover measures will be installed. 3. Perimeter Protection: Per sheet C2.01 of the civil plans, silt fence will be used for perimeter protection.. Silt fence will be installed along the perimeters of those areas that will be receiving silt -laden runoff. 4. Traffic Area Stabilization: A construction entrance will be installed at the entrance to the project site. See sheets C2.01 and C2.31 for location of construction entrance and detail. 5. Sediment Retention. The proposed detention/water quality vault will be used for sediment retention. Sediment retention will be designed per the 2005 KCSWDM Appendix D. Surface Area: Q10 (04120d15.tsfj = 1.74 cfs (See attached KCRTS Flow Frequency Analysis in Section 4B of this Report) SA = 2080 sf/cfs * Q10 SA = 2080 sf/cfs * 1.74 cfs = 3,619 SF SA Provided = 5,888 SF > 3,619 SF => OK Riser Diameter: The 15" riser on the control structure will be used for the principle spillway. The riser was sized to accommodate the developed 100-year, 15-minute return period storm. See Section 4B of this Report for sizing calculation. Emergency Overflow Spillway: The 15" riser on the control structure will be used for emergency overflow. The riser was sized to accommodate the developed 100-year, 15-minute return period storm. See Section 4B of this Report for sizing calculation. 6. Surface Water Collection: Interceptor swales will be used to direct all sediment - laden runoff to the sedimentation vault. See sheets C2.01 and C2.31 for location of swales and details. 7. Dewatering Control: A note on sheet C2.01 addresses the procedure for discharge/treatment of runoff from dewatering. 8. Dust Control: A note on sheet C2.01 addresses the procedure for dust control should soils become too dry. 9. Flow Control: The proposed detention/water quality facility will be used for sediment retention therefore, discharge from the facility will be per the Conservation (Level Two) Flow Control standard. Design of the SWPPS plan was completed in conformance with Section 2.3.1.4 in the 2005 KCSWDM. The ESC and SWPPS plan contains notes establishing what materials will not be allowed on the site along with notes describing BMPs for treatment of materials that will be on the site. Since no storage of liquids including fuel will be allowed on the site, no spill prevention report and/or clean up report is required. Vehicle maintenance will not be allowed on the site. Storage of construction materials and wastes will be stored within the "potential stockpile area" delineated on the ESC and SWPPS plan. Any concrete waste or waste from sawcutting or surfacing will be discharged to formed areas awaiting installation of concrete or asphalt and/or to a lined sump as specified in the notes and shown on the ESC and SWPPS plan. The contractor shall designate a person as the responsible representative in charge of erosion control and maintenance of all erosion control and stormwater pollution prevention facilities. 9. BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT: A blank "Declaration of Covenant and Grant of Easement" along with maintenance and operation instructions for the "Perforated Pipe Connection" and "Restricted Footprint" are attached on the following pages. The blank "Declaration of Covenant and Grant of Easement" will be filled out and recorded during final plat. The "Facility Summary Sheet" and "Bond Quantities Worksheet" are attached on the following pages. RECORDING REQUESTED BY AND WHEN RECORDED MAIL TO. - RECORDING COVER SHEET DECLARATION OF COVENANT AND GRANT OF EASEMENT Grantor: Grantee: Legal Description: Additional Legal(s) on: Assessor's Tax Parcel ID#: DECLARATION OF COVENANT AND GRANT OF EASEMENT For Stormwater Flow Control Best Management Practices 1N CONSIDERATION of the following approved King County (check one of the following) ❑ residential building permit, ❑ commercial building permit, ❑ clearing and grading permit, ❑ subdivision permit, or ❑ short subdivision permit for Application No. relating to real property ("Property") legally described as follows: The Grantor(s), the owner(s) in fee of the above described parcel of land, hereby covenants with King County, a political subdivision of the state of Washington its successors in interest and assigns ("King County"), that it will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs i and 2 and 4 through 7 below with regard to the Property, and hereby grants an access easement on and to the Property to King County, for the purposes described in Paragraph 3 below. Grantor(s) hereby grants, covenants, and agrees as follows: l . Owner(s) of the Property shall retain, uphold, and protect the stormwater management devices, features, pathways, limits, and restrictions, known as flow control best management practices ("Flow Control BMPs"), shown on the approved Flow Control BMP Site Plan for the Property attached hereto and incorporated herein as Exhibit A. 2. Owner(s) of the Property shall at their own cost, operate, maintain, and keep in good repair, the Property's Flow Control BMPs as described in the approved Design and Maintenance Details for each BMP attached hereto and incorporated herein as Exhibit B. 3. King County shall have a nonexclusive perpetual access easement on the Property in order to ingress and egress over the Property for the sole purposes of inspecting and monitoring the Property's Flow Control BMPs, and if applicable in accordance with the terms of Paragraph 4 below, performing any corrective work required to bring the Property's Flow Control BMPs into compliance with Title 9 of the King County Code. 4. If King County determines that maintenance, repair, restoration., and/or mitigation work is required to be done to the Flow Control BMPs and has not been performed by the Property owner(s), the Director of the Water and Land Resources Division of the King County Department of Natural Resources and Parks small give notice to the Property owner (s) of the specific maintenance, repair, restoration, and/or mitigation work (Work) required pursuant to Title 9 of the King County Code. The Manager shall also set a reasonable time in which the Work is to be completed by the Property owner(s). If the Work is not completed within the time set by the Division Director, King County may perform the required Work. Written notice will be sent to the Property owner(s) stating King County's intention to perform the Work. Performance of the Work by King County will not commence until at least seven (7) days after such notice is mailed. If, within the sole discretion of the Water and Land Resources Division Director, there exists an imminent or present danger, the owner hereby waives the seven (7) day notice period and the Work will begin immediately. 5. The owner(s) of the Property shall assume all responsibility for the cost of any Work required to be done to the Flow Control BMPs. Such responsibility shall include reimbursement to King County within thirty (30) days of the receipt of the invoice for any such Work performed by King County in accordance with the terms of Paragraph 3 above. Overdue payments will require payment of interest at the current legal rate as liquidated damages. In the event that King County does not receive reimbursement within the required time frame, it may elect to place a lien on the Property and act upon the Iien in accordance with the terms and procedures specified in Chapter 23.40 of the King County Code, as amended from time to time. If legal action is taken to enforce the provisions of this Paragraph, the prevailing party is entitled to costs and attorney's fees. 6. Apart from performing routine landscape maintenance, the Property owner(s) is (are) hereby required to obtain written approval from the Water and Land Resources Division Manager of the King County Department of Natural Resources and Parks prior to performing any alterations or modifications to the Flow Control BMPs. Any notice or consent required to be given or otherwise provided for by the provisions of this Declaration of Covenant and Grant of Easement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail, return receipt requested, whichever occurs sooner. 7. This Declaration of Covenant and Grant of Easement is intended to promote the efficient and effective management of surface water drainage on the Property, and it shall inure to the benefit of all the citizens of King County, its successors and assigns. This Declaration of Covenant and Grant of Easement shall run with the land and be binding upon Grantor(s), and Grantor's (s') successors in interest and assigns. 8. This Declaration of Covenant and Grant of Easement may be terminated by execution of a written agreement by Grantor(s) and King County expressing their mutual agreement to terminate this Declaration of Covenant and Grant of Easement. IN WITNESS WHEREOF, this Declaration of Covenant and Grant of Easement is executed this day of STATE OF WASHINGTON) )SS COUNTY OF KING } 20— By Its By Its On this day of , 20before me, the undersigned, a Notary Public in and for the State of , duly commissioned and sworn personally appeared , to me known to be the individual described in and who executed the foregoing instrument, and acknowledged to me that he signed and sealed the said instrument as h free and voluntary act and deed for the uses and purposes therein mentioned. written. WITNESS my hand and official seal hereto affixed the day and year in this certificate above Printed name Notary Public in and for the State of Washington, residing at My appointment expires MAINTENANCE AND OPERATION INSTRUCTIONS FOR PERFORATED PIPE CONNECTION Your property contains a stormwater management flow control BMP (best management practice) called a "perforated pipe connection," which was installed to reduce the stormwater runoff impacts of some or all of the impervious surface on your property. A perforated pipe connection is a length of drainage conveyance pipe with holes in the bottom, designed to "leak" runoff, conveyed to the pipe, into a gravel filled trench where it can be soaked into the surrounding soil. The connection is intended to provide opportunity for infiltration of any runoff that is being conveyed from an impervious surface (usually a roof) to a local drainage system such as a ditch or roadway pipe system. The size and composition of the perforated pipe connection as depicted by the flow control BMP site plan and design details must be maintained and may not be changed without written approval either from the King County Water and Land Resources Division or through a future development permit from King County. The soil overtop of the perforated portion of the system must not be compacted or covered with impervious materials. MAINTENANCE AND OPERATION INSTRUCTIONS FOR RESTRICTED FOOTPRINT Your property contains a stormwater management flow control BMP (best management practice) known as "restricted footprint," the practice of restricting the amount of impervious surface that may be added to a property so as to minimize the stormwater runoff impacts caused by impervious surface. The total impervious surface on your property many not exceed square feet without written approval either from the King County Water and Land Resources Division or through a future development permit from King County. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL STORMWATER FACILITY SUMMARY SHEET DDES Permit �- P� Number (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Name Date _Z f 9 10-7 Downstream Drainage Basins Major Basin Name"D cnyr� Immediate Basin Name_ \C�(�k Qry-y Flow Control: Flow Control Facility Name/Number Facility Location If none, Flow control provided in regionaUshared facility (give location) No flow control required Exemption number General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ponds ponds vaults tanks tanks trenches Control Structure Location Type of Control Structure Number of Orifices/Restrictions Size of Orifice/Restriction: No. 1 - ct V " No. 2 k , 6 tr No. 3 No. 4 Flow Control Performance Standard 2005 Surface Water Design Manua] 111105 1 DING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Live Storage Volume (p CJF- Depth 9.8'1 l Volume Factor of Safety Number of Acres Served - 4. 15 Number of Lots dZ Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade _ Depth of Reservoir above natural grade Facility Summary Sheet Sketch All detention, infiltration and water quality facilities must include a detailed sketch. (I l "x17" reduced size plan sheets may be used) 111105 2005 Surface Water Design Manual 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Water Quality: Type/Number of water quality facilities/SMPs: biofiltration Swale (regular/wet/ or continuous inflow) large) large) above combined detention/wetpond (wetpond portion basic or large) combined detention/wetvault filter strip flow dispersion farm management plan landscape management plan oil/water separator (baffle or coalescing plate) Liner? catch basin inserts: Manufacturer pre -settling pond pre -settling structure: Manufacturer sand filter (basic or large) sand filter, linear (basic or sand filter vault (basic or sand bed depth (inches) stormwater wetland storm filter wetpond (basic or large) wetvault Is facility Lined? If so, what marker is used high flow bypass structure (e.g., flow-splitter catch basin) source controls Design Information Water Quality design flow Water Quality treated volume (sandfilter) Water Quality storage volume (wetpool) Facility Summary Sheet Sketch 2005 Surface Water Design Manual 111105 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL All detention, infiltration and water quality facilities must include a detailed sketch. 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AAs near s JIl6.D' isurs3w 4r LA= WE JS9d W BS AMAfL� AMN- 9AfPWfC Of►1�T:AR7M AFa A4 AEOD (PP) �, e OW A ANW SAPAR<P Nam Amin (I�a airavW awzr N A6iAiCAP LAD RAW aPMMS w ARA4i: off -viux Ax r,�a -MM t s' Lw INSODwr LFT Am WN MAW n' ��•al1P'= SAPS; ORL*" M-xw arW 2 -0if (TfP) � sMEAP GAE RESMICTOR DETAIL i-f' MM T'-�r Asir Ar BEW WN PLUS PW AFL LI'AAk7EN AS NOW aY HE PLANS CLE4NOUT DETAIL ACf SC'ALF T• 2V= Wr frFAffA00 or owM ALarABRWL SMR6W 9WL EtMV W AEAWROE R&W Wa[wu Ar A>wswaeAb7&MALMT �AE dTT7WH AM7 9WF5 arEas7 Lnax ,M#AWrJEAGMUL !' aiCPTT N FAWF T- 71 O s A" W 9AYL Ar ArASWMAMLY mu QWw NN 9e4iwnW AS ArLC `« 1 WSWW-9W w" AArNLYr SW S= 4 AM7'eS RIP -RAP OUTFALL DETAIL Ala SME sr' Al'lY�-LEiALC-� AAAaWSR SAS 1 ' ' BMW or a 9dF eLlt RAW L — — — — -J RESTRIO TOR PLAN VIEW SORE` T '�r R%Fr e OF A MD && eta y mg m Saar I-e•mu Now a7F LAP ow aWZiEN 0V RAF ELBOW DETAIL ---_------- ----- RAAIwALL --- - - _ r ALAN FA W L Ae' AFM y - c e 4' A595 FM So" XBOY CTRiRFMCXW axaar — FAN JEW Wr ROOr PERFORATED STUB -OUT CONNECTION HR A W5 A'M W MUM C2 IT A;A4AE7A]W TEF MJ EC" AMP fWP MOWM MC LOTS Alp SCALE -YW kE RAN YL WW )w IE tint of ➢e rt era Gaumenh� Series co b*r bow CWx OMFLR l9FlElC fide Uwm kW w Q W w 4 O Q4 4 Q PROJFi,T NUMBER 04120 DQAVANG 04.32 SHEET 9 OF 14 ¢I 0 10.OPERATIONS AND MAINTENANCE MANUAL: A maintenance and operations manual is not required since all drainage facilities will be public. Site Improvement Bond Quantity Worksheet Web date: 11/21/2005 (* King County Department of Development & Environmental Services 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 For alternate formats, call 206-296-6600. 206-296-6600 M 206-296-7217 Project Name: Talbot Ridge Date: 11I6l07 Location: 19200 Blk 102nd Avenue SE Project No.: L05P0007 Activity No.: L07SR012 Clearing greater than or equal to 5,000 board feet of timber? X yes no If yes, Forest Practice Permit Number: (RCW 76.09) Page 1 of 9 04120BQW.xis Note: All prices include labor, equipment, materials, overhead and profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the IRS Means database. Unit prices updated: 02/12/02 Version: 04/22/02 Report Date: 11/28/07 Site Improvement Bond Quantity Worksheet Web date: 11/21/2005 y Reference #' Unit Pnc Unit = Quanti # of i A lications Cash EROSlN1.SEDLMENT CONTROL. Number zl k;k I Backfill & compaction -ern ban kment ESC-1 $ 5.62 CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 $ 67.51 Each 15 1 1013 Crushed surfacing 1 1/4" minus ESC-3 WSDOT 9-03.9(3) $ 85.45 CY Ditching ESC-4 $ 8.08 CY 215 1 1737 Excavation -bulk ESC-5 $ 1.50 CY Fence, silt ESC-6 SWDM 5.4.3.1 $ 1.38 LF 840 1 1159 Fence, Temporary (NGPE) ESC-7 $ 1.38 LF H droseedin ESC-8 SWDM 5.4.2.4 $ 0.59 SY 14500 1 8555 Jute Mesh ESC-9 SWDM 5.4.2.2 $ 1.45 SY Mulch, by hand, straw, 3" deep ESC-10 SWDM 5.4.2.1 $ 2.01 SY Mulch, by machine, straw, 2" deep ESC-11 SWDM 5.4.2.1 $ 0.53 SY Piping, temporary, CPP, 6" ESC-12 $ 10.70 LF Piping, tempura , CPP, 8" ESC-13 $ 16.10 LF Piping, temporary, CPP, 12" ESC-14 $ 20.70 LF Plastic covering, 6mm thick, sandbagged ESCA 5 SWDM 5.4.2.3 $ 2.30 SY Rip Rap, machine laced; slopes ESC-16 WSDOT 9-13.1 2 $ 39.08 CY Rock Construction Entrance, 50'x15'x1' ESC-17 SWDM 5.4.4.1 $ 1,464.34 Each Rock Construction Entrance, 100'x15'x1' ESC-18 SWDM 5.4.4.1 $ 2,928.68 Each 1 1 2929 Sediment pond riser assembly ESC-19 SWDM 5.4.52 $ 1,949.38 Each Sediment trap, 5' high berm ESC-20 SWDM 6.4.5.1 $ 17.91 LF Sed. trap, V high, riprapped spillway berm section ESC-21 SWDM 5.4.5.1 $ 68.54 LF Seeding, by hand Soddin , 1" dee , level round ESC-22 SWDM 5.42.4 $ 0.51 SY ESC-23 SWDM 5.4.2.5 $ 6.03 SY Sodding, 1" deep, sloped ground ESC-24 SWDM 5.42.5 $ 7.45 SY TESC Supervisor ESC-25 $ 74.75 HR Water truck, dust control ESC-26 SWDM 5.4.7 $ 97.75 HR WRITE-IN..) . see a46.9 Each ESC SUBTOTAL: 30% CONTINGENCY & MOBILIZATION: ESC TOTAL: COLUMN: Page 2 of 9 04120BQW,xls $ 15,392.73 $ 4,617.82 $ 20,010.55 A Unit prices updated: 02/12/02 Version: 04/22/02 Report Date: 11/28/07 OlLe II i iprovur nei IL 601 iu Quai itlty 4o, nal lest. v : 111 u t a . stIng. , RigEtt-oi Wy a qµ '"; , , Future Public r Road Improvements 8� 1]raina a FacihfEe' Pnvate, G k Improvements, ' Quantity Completed (t3ond Reduction)* Quant: complete = Cost Unit Price Cfmt `' ; Quant 'Cost' Quant'c" , t Cost x _ Quant." : Cosh'" GENERAL ITEMS j.,�. No. Backfill & Compaction- embankment GI - 1 $ 5.62 CY 2112 11,869.44 744 4,181.28 104761 58,875.12 Backfill b Compaction- trench GI -2 $ 8.53 CY Clear/Remove Brush, by hand GI -3 $ 0.36 SY Clearin IGrubbin !Tree Removal GI -4 $ 8,876.16 Acre 0.5 4,438.08 3 26,628.48 Excavation - bulk GI - 5 $ 1.50 CY 484 726.00 4843 7,264.50 7639 11,458.50 Excavation - Trench GI - fi 1 $ 4.06 CY Fencing, cedar, 6' hi h GI - 7 $ 18.55 LF Fencing, chain link, vinyl coated, 6' hi h GI - 8 $ 13.44 LF 148 1,989.12 Fencing, chain link, gate, vinyl coated, 2 GI - 9 $ 1,271.81 Each Fencing, split rail, S hi h GI - 10 $ 12.12 LF Fill & compact - common barrow GI - 11 $ 22.57 CY Fill & compact - gravel base GI - 121 $ 25.48 CY Fill & compact - screened topsoil GI - 13 $ 37.85 CY Gabion, 12" deep, stone filled mesh GI - 14 $ 54.31 SY Gabion, 18" deep, stone filled mesh GI - 15 $ 74.85 SY Gabion, 36" deep, stone filled mesh GI - 16 $ 132.48 SY Grading, fine, by hand GI - 17 $ 2.02 SY Grading, fine, with grader GI - 18 $ 0.95 SY Monuments, Y lon GI - 19 $ 135.13 Each 3 405.39 Sensitive Areas Sin GI - 20 $ 2.88 Each Sodding, 1" deep, sloped ground GI - 21 $ 7.46 SY Surveying, line & grade GI - 22 $ 788.26 Da Surveying, lot focationllines GI - 23 $ 1,556.64 Acre Traffic control crew 2 flaggers) GI - 24 $ 85.18 HR Trail, 4" chipped wood GI - 25 $ 7.59 SY Trail, 4" crushed cinder GI - 26 $ 8.33 SY Trail, 4" top course GI - 27 $ 8.19 SY Wall, retaining, concrete GI - 28 $ 44,16 SF Wall, rockery IGI - 29 $ 9.49 SF 21501 20,403.50 Page 3 of 9 SUBTOTAL 12,595.44 18,278.37 117,365.60 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 4122102 04120BQW.xis Report Date: 11128/07 OilC ImmOVivi ilea it LJOi iu Quai itity v Jai nay ie.,,. w 11f. EXisting = Futun Right-of-way Road ErttK Draina" e l Unit Price Unit Quant. Cost. Quanta ROADfMPROVEMENT Na' Bond Reduction" Quant. €... ` Complete Cost AC Grindin , 4' wide machine < 1000s Rl - i $ 23.00 SY AC Grinding, 4' wide machine 1000-200 RI-2 $ 5.75 SY AC Grinding, 4' wide machine > 2000s RI-3 $ 1.38 SY AC Removal/Disposal/Repair RI - 4 $ 41.14 SY 1275 52,453.50 Barricade, type 1 RI-5 $ 30.03 LF Barricade, type III Permanent RI-6 $ 45.05 LF Curb & Gutter, rolled RI-7 $ 13.27 LF 890 11,810.30 415 6,507.05 Curb & Gutter, vertical Curb and Gutter, demolition and dis osa RI - 8 RI - 9 $ 9.69 $ 13.58 LF LF 225 2,180.25 206 1,996.14 Curb, extruded asphalt RI - 10 $ 2.44 LF 275 671.00 Curb, extruded concrete RI - 11 $ 2.56 LF Sawcut, asphalt, 3" depth RI - 12 $ 1.85 LF 260 481.00 Sawcut, concrete, per V depth RI - 13 $ 1.69 LF Sealant, asphalt RI - 14 $ 0.99 LF 260 257.40 Shoulder, AC, see AC road unit price RI - 15 $ - SY Shoulder, gravel, 4" thick RI - 16 $ 7.53 SY Sidewalk, 4" thick Sidewalk, 4" thick, demolition and dis os RI - 17 RE -18 $ 30.52 $ 27.73 SY SY Sidewalk, 5" thick RI - 19 $ 34.94 SY 120 4,192.80 415 14,500.10 Sidewalk, 5" thick, demolition and dis os RI - 20 $ 34.65 SY Sign, handicap Striping,per stall RI - 21 RI - 22 $ 85.28 $ 5.82 Each Each Stri in , thermoplastic, for crosswalk RI - 23 $ 2.38 SF Striping, 4" reflectorized line RI - 24 $ 0.25 LF 1615 403.75 Page 4 of 9 SUBTOTAL 69,901.30 29,044.94 5,507.05 Unit prices updated: 02/12102 'KCC 27A authorizes only one bond reduction. Version: 4122102 041206QW.xls Report Date: 11128/07 orie Iri provtrm1em 30HU QUantlty 401K51leelL Unit PnI lJIII Quan ROAD SURFACING (4" Rock 2.5 base;:g 1.5" top eourse) °�Far'93 ......... ... .. ......... For KCRS '93, additional 2.5" base add IRS - 1 $ 3.60 SY 21 AC Overlay, 1.5" AC RS - 2 $ 7.39 SY AC Overlay, 2" AC RS - 3 $ 8.75 SY :AC Road, 2", 4" rock, First 2500 SY RS - 4 $ 17.24 SY AC Road, 2", 4" rock, Qty. over 2500SY IRS - 5 $ 13.36 SY AC Road, 3", 4" rock, First 2500 SY IRS - 6 $ 19.69 SY 21 ;AC Road, 3", 4" rock, Qty. over 2500 SY RS - 7 $ 15.81 SY !AC Road, 5", First 2500 SY IRS - 8 $ 14,57 SY AC Road, 5", Qty. Over 2500 SY IRS - 9 $ 13,94 SY ,AC Road, 6", First 2500 SY RS - 1 C $ 16.76 SY 'AC Road, 6", Qty. Over 2500 SY IRS - 11 $ 16.12 SY !Asphalt Treated Base, 4" thick IRS - 1 $ 9.21 SY Gravel Road, 4" rock, First 2500 SY IRS - 1 $ 11.41 SY Gravel Road, 4" rock, Q . over 2500 SY IRS - 1 $ 7.53 SY PCC Road, 5", no base, over 2500 SY IRS - 1 $ 21.51 SY PCC Road, 6", no base, over 2500 SY IRS - 1 $ 21.87 SY Thickened Edge RS - 1 $ 6.89 1 LF Page 5 of 9 *KCC 27A authorizes only one bond reduction. 04120BQW.xls SUBTOTAL 50,073.50 V : 11/ 17201 22.979.201 5951 7 29,171.20 10, 091.20 Unit prices updated: 02/12/02 Version: 4122/02 Report Date: 11128107 OlLe li i provtai nei i� r3Oi iu Qudi itity 4oil snot leV� V 11! rExistEng. Future Public _Private Bond Reduction' Fight-af-way' tRoad lmprovamanls { improvements :q ,r n &'Ordina a Facilities . MID iMA�� 1 Quant ,`r Unit Price Unit '' Qu2nt. - Cost , Quanf: Cast QuanL , %,fig 'Cost" Com lete Cost DRAI NAGS , (CPP=:,Coriugateci Plastic Pipe,` N12 or Equivalent) Far Culvert prices ; Avera a of 4' cover was assumetl. Assume erioratetl PVC is same rice as solid pipe. Access Road, RID D - 1 $ 16,74 SY 2551 4,268.70 Bollards - fixed D - 2 $ 240.74 Each 21 481.48 Bollards - removable D - 3 $ 452.34 Each 31 1,357.02 CBs include frame and lid CB Type l D- 4 $ 1,257.64 Each 3 3,772.92 9 11,318.76 CB Type IL D - 5 $ 1,433.59 Each CB Type II, 48" diameter D - 6 $ 2,033.57 Each 3 6,100.71 3 6,100,71 for additional depth over 4' D - 7 $ 436.52 FT i 2,619.12 7 3,055.64 CB Type II, 54" diameter D - 8 $ 2,192.54 Each for additional depth over 4' 0-9 $ 486.53 FT CB Type II, 60" diameter D - 10 $ 2,351.52 Each for additional depth over 4' D - 11 $ 536.54 FT CB Tvpe II, 72" diameter D - 12 $ 3,212.64 Each for additional depth over 4' D- 13 $ 692.21 FT Through -curb Inlet Framework (Add) D- 14 $ 366.09 Each Cleanout, PVC, 4" D - 15 $ 130.55 Each Cleanout, PVC, 6" D - 16 $ 174.90 Each 22 3,847.80 Cleanout, PVC, 8" D- 17 $ 224.19 Each Culvert, PVC, 4" D- 18 $ 8.64 LF Culvert, PVC, 6" D - 19 $ 12.60 LF 7851 9,891.00 Culvert, PVC, 8" D - 20 $ 13.33 LF Culvert, PVC, 12" D - 21 $ 21.77 LF Culvert, CMP, 8" D - 22 $ 17,25 LF Culvert, CMP, 12" D - 23 $ 26.45 LF Culvert, CMP, 15" D - 24 $ 32.73 LF Culvert, CMP, 18" D - 25 $ 37.74 LF Culvert, CMP, 24" D - 26 $ 53.33 LF Culvert, CMP, 30" D - 27 $ 71.45 LF Culvert, CMP, 36" D - 28 $ 112.11 LF Culvert, CMP, 48" D - 29 $ 140.83 LF Culvert, CMP, 60" D - 30 $ 235.45 LF Culvert, CMP, 72" D - 31 $ 302.58 LF Page 6 of 9 SUBTOTAL 12,492.75 26,582.31 13,738.80 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 4/22/02 04120BQW.xls Report Date: 11/28/07 OlLe lmprovciflem dui iu QUGif IbLy v4oi n;�hel=L 1 11 b aill toil _ — ���71�4— DRAINAiallyCON7INUEn No_ Unit Price Unit..' ' Qu Culvert, Concrete, 8" D - 32 $ 21.02 LF Culvert, Concrete, 12" D - 33 $ 30.05 LF Culvert, Concrete, 15" D - 34 $ 37.34 LF Culvert, Concrete, 18" D - 35 $ 44.51 LF Culvert, Concrete, 24" D - 36 $ 61.07 LF Culvert, Concrete, 30" D - 37 $ 104,18 LF Culvert, Concrete, 36" D - 38 $ 137.63 LF Culvert, Concrete, 42" D - 39 $ 158.42 LF Culvert, Concrete, 48" D - 40 $ 175.94 LF Culvert, CPP, 6" D - 41 $ 10.70 LF Culvert, CPP, 8" D - 42 $ 16.10 LF Culvert, CPP, 12" D - 43 $ 20.70 LF Culvert, CPP, 15" D - 44 $ 23.00 LF Culvert, CPP, 18" D - 45 $ 27.60 LF Culvert, CPP, 24" D - 46 $ 36.80 LF Culvert, CPI', 30" D - 47 $ 48,30 LF Culvert, CPP, 36" D - 48 $ 55.20 LF Ditchin D - 49 $ 8,08 CY Flow Dispersal Trench 1,436 base+ D - 50 $ 25.99 LF French Drain T de th D - 51 $ 22.60 LF Geotextile, laid in trench, polypropylene D - 52 $ 2.40 SY Infiltration pond testing D - 53 $ 74.75 HR Mid -tank Access Riser, 48" dia, 6' dee D-541 $ 1,605.40 Each Pond Overflow Spillway D - 55 $ 14.01 SY RestrictorlOil Separator, 12" D - 56 $ 1,045.19 Each RestrictorlOil Separator, 15" D - 57 $ 1,095.56 Each RestrictorlOil Separator, 18" D - 58 $ 1,146.16 Each Riprap, placed D - 59 $ 39.08 CY Tank End Reducer 36" diameter) D -60 $ 1,000.50 Each Trash Rack, 12" D - 61 $ 211.97 Each Trash Rack, 15" D - 62 $ 237.27 Each Trash Rack, 18" D - 63 $ 268.89 Each Trash Rack, 21" D - 64 $ 306.84 1 Each Page 7 of 9 SUBTOTAL 1791 3705.3I 11251 23287.5 81 312.64 4017.94 11 1 24383.06 Private . Bond Reduction* 'jr F improvements,:y, r? Gluant. U. Cosy Complete Cost Unit prices updated: 02112/02 *KCC 27A authorizes only one bond reduction. Version: 4/22/02 04120BQW.xls Report Date: 11128107 1 11 OlLe ImprovGi nbi lL I3(ll IU Quaff ItiLy vlOI txahE,�,, SUBTOTAL SUBTOTAL (SUM ALL PAGES): 30% CONTINGENCY & MOBILIZATION: GRANDTOTAL: COLUMN: Page 8 of 9 139,080.93 41.724.28 180,805.21 B 311, 000.00 438,459.88 131,537.96 569,997.84 C 146,702.65 44,010.80 190, 713.45 D E Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 4/22/02 04120BQW,xls Report Date: 11128107 Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: Talbot Ridge PE Registration Number: Gina R. Brooks, PE #36478 Web date: 11/2112005 Date: 1116/07 Tel. #: (425)885-7877 Firm Name: Care Design, Inc Address: 14711 NE 29th PL, Bellevue WA 98007 Project No: L05P0007 ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS Stabilization/Erosion Sediment Control (ESC) Existing Right -of -Way Improvements Future Public Road Improvements & Drainage Private Improvements Calculated Quantity Completed Total Right -of Way and/or Site Restoration Bond*/** (First $7,500 of bond* shall be cash.) Performance Bond* Amount (A+B+C+D) = TOTAL Reduced Performance Bond* Total *°* Maintenance/Defect Bond* Total NAME OF PERSON PREPARING BOND* REDUCTION: PERFORMANCE BOND* AMOUNT (A) $ 20,010.5 (B) $ 180,805.2 (C) $ 569,997.8 (D) $ 190,713.4 (A+B) $ 200,815.8 (T) $ 961,527.0 Minimum bon amount is $1000. Gina R. Brooks BOND"AMOUNT REQUIRED AT RECORDING OR TEMPORARY OCCUPANCY "*" (E) $ T x 0.30 $ 288,458.1 OR (T-E) $ 961,527.0 Use larger of Tx3O% or - ) Date: PUBLIC ROAD & DRAINAGE MAINTENANCEfDEFECT BOND* (B+C) x 0.25 = $ 187,700.8 1116/07 * NOTE. The word "bond" as used in this document means any financial guarantee acceptable to King County. "* NOTE. KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on- and off -site needs to be included. Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity. "** NOTE: Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes. SURETY BOND RIDER NOTE: If a bond rider is used, minimum additional performance bond shall be $ 760,711.3 (C+D)-E REQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DDES Page 9 of 9 Unit prices updated: 02112/02 Check out the DDES Web site at www.metrokc-gov/ddes Version: 4/22/02 04120BQW.xls Report Date: 11/28/07