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Peer Redline Drainage Report 001 ~~ ~ ' TAHOMA TERRA FAIRWAY MULTI-FAMILY YELM, WASHINGTON ,p ~ c~ ~~~ 1 DRAINAGE REPORT KPFF Consulting Engineers 1 4200 Sixth Avenue SE, Suite 309 Lacey, WA 98503 ~ N 1 i ' June 18, 2007 T ` w 1 i 1 t FINAL DRAINAGE REPORT Tahoma Terra Fairway Multi-family Housing Yelm, Washington June 18, 2007 PROJECT INFORMATION Prepared for: TT PH 3-8 LLC Contact: Doug Bloom REVIEWING AGENCY Jurisdiction: City of Yelm, Washington Project Number: 406037.03 Project Contact: James E. Gibson, P.E. PROJECTfNGINEER Prepared by: KPFF Consuking Engineers 4200 6~' Avenue SE, Ste. 309 Lacey, WA 98503 Tel: (360) 292-7230 Fax: (360) 292-7231 Contact: Clint Pierpoint, Civil Engineer KPFF Project: File Number. 1a20064406032 Tahoma Terra 1-2\Fairway Townhomes-406032.03tProjed DocumentslFinal Drainage Report Tahoma Terra Faitway.doc PROJECT ENGINEERS CERTIFICATION: I hereby cedify that this Final Rminage Report and Erosion Confrol Plan for Tahoma ierta Fairway in Yelm, Washington has been prepared 6y me or under my supervision antl meeW the minimum standards of the Cdy of Yelm and noonal standards of engineering practice. I urMersNarM that the CRY does not and witl not assume IiabiNty for the su(ficienq. suitability, or pertonnance of drainage facilities designed by me. EXPIflES 270 i 1 II 1 1 1 1 Table of Contents PART I -STORM DRAINAGE REPORT ....................................... ...............1 Section 1 - ProPased Prolect DescriPtlon ...................._.........__.......... ....._........1 Sectiov 2 - Existing Conditions........___......_._._ ..........:.................... ..._....._...2 Section 3 -Infiltration Rates/Soils RePOrt .._......_ ..................._......... ...............'L Section 4 -Wells and Septic Systems ..................................._............. ...............3 Section 5 -Fuel Ta¢ks...._.__....__......._..........._._.._......_........_.._.... ..__.........3 Sectiov 6 -Sub-Basin DescriPtion ....................................................... ...............3 Sectio¢ 7 - AnalYSis of the 100~Year Flood .............._............_....... _... ..._....._...3 Sectiov 8 -Aesthetic Considerations for Facilities ............._.............. ........._.._ 3 Section 9 -Facility Sizing and Downstream Analysis........__ ............ ...............3 Section 30~ Covenants, Dedications and Easments.._..._...._......._._ . ..............A PART II -EROSION CONTROL REPORT ................................... ...............4 Section 1 -Constriction Sequence And Procedure ................._......... .._......._...4 Section 2 - TraPPing Sediment ._......._ ......................................_....... ................4 Section 3 -Permanent Erosion Control & Site Restoration ......._..... ......._.......5 Section 4 - Geotechnical Analysis And RePOrt ............._..........__..._. ................5 Section 6 - IaePection Sequcnce .............._..._........._....._................... ...._....._...5 Section 6 -Control Of Pollutants Other Than Sedimeves.........._ ..... .............._ 5 PART III -MAINTENANCE FLAN ................................................ ................6 Section l-Required Mai to auce _......_ _.__ .. ....__......_6 Section 2 - ResPOnsible Orga¢izatiov.._ ............._......_...................._ .............. 11 Sectiov 3 -Vegetation Management Plan..........._._ ...............__....... .............. 11 Section 4 -Source Control .. ............. .. . ._....._.._ l l APPENDICES Appendu 1 Storm Drainage Calculations Appendix 2 Drainage and TESC Plan Appendix 3 FEMA Map Appendu 4 Facility Summary Forms Appendu 5 Soil Evaluation Report Appendu 6 Maintenance Agreement Appendix 7 Vicinity Map ' ii Part I Storm Drainage Report ' Taeoma Terra Fairway Multi Famlly -Drainage Report 1 1 1 1 PART I -STORM DRAINAGE REPORT SECTION 1 -PROPOSED PROJECT DESCRIPTION Parcel Number: 78640000009 Total Site Area: 5.04 acres Address: Not yet arraigned Yelm, WA 98597 Zoned: MPC Required Permits: Building, Grading, Paving, Utility Section, Township, Range: Section 24, Township 17 North, Range 1 East, W.M., Thurston County, WA Site Location The project site is located in Yelm, Washington southwest of the intersection of Longmire Street SE and Durant Street S in Thurston County, Washington. The site is bounded on the east by Tahoma Terra Golf and Country Club. Project Overview The applicant is proposing to construct 3multi-family residential buildings with atotal of 48 units, Each building has a footprint of approximately 8,525 square-feet. The site will be constructed in one phase and will include appropriate erosion control measures as needed, grading, storm drainage improvements and connection to existing underground utllilies including water and sanitary sewer. Storm Drainage Improvements: The total site area is 5.04 Acres. Proposed On-site Conditions • 0.56 acres of roof area • 0.06 aces of impervious sidewalk • 1.04 acres of pervious pavement • 3.36 acres of landscaped/undisturbed pervious area Stormwater Treatment/StdrageAnfiltration: Stormwater treatment requirements are based on the 1992 edition of the WSDOE Stormwater Management Manual and the Low Impact Development Technical Guidance Manual for Puget Sound. Pervious pavement will be used onahis project. Stormwater calculations are provided in Appendix 1. Treatment and storage will occur ' through the infiltration through the pervious pavement and engineered base material. See Appendix 2 far a pavement cross section. KPFF Consulting Engineers ' June 18, 2007 i Tahoma Tens Fairway Multi Family -Drainage Report The Basin: The Basin includes the 5.04 acres of the proposed site and 0.27 awesof otfstte area to the east. The offsite areatothe east is vegetatedwith oak trees and native brush as part of Tahoma Terra Golfand Country Club. Alf surface runoff will be infiltrated through the pervious pavement. Roof Runoff: Runoff from the roofs will be routed to root downspout drains that will be integrated into the pervious pavement reservoir base course. SECTION 2 -EXISTING CONDRIONS The project site is bounded on the north, west and south by Thompson Creek and Associated wetlands; as delineated by the Coot Company in March of 2005. The project is bounded on the east by Tahoma TemaGOlf and Country Club. Site Topography is slightly slopipg with gradesbetween 2% and 7°k:. A high point. ridge/peninsula located centrellyon the site lies in an east to west pasRion. Generally the site slopes away to the north, west and south from this ridge,` Elevatibns range from ahigh of 338 ft. on the described ridge to a low of 330 ft along ahe northwest property line. Site vegetation consists of patches of uncropped pasture-grasses and indigenous brush amongst amedium density deciduous and conlferfwest'Theeast side of the property is ident~ed per the Thurston County GeoData Center. asanoak- coniferforest or woodland canopyper DNR and-wilfbe protected and preserved by this project. On-site soils are a combination of well-drained Nisqually and Spanaway aerie: soils formed in glacial outwash. There are no man-made drains, channels, or swales, within the project site. The site is located adjacent to Thompson Creek and Associated wetlands and is within the related buffer. The northern portion of the site is identified as a high ground water flood. hazard area per the Thurston County GeoData Center Thesiteis notident~ed as a well head protection area o[an aquifer sensitive area per the Thurston County GeGData Center, but site condRions dictate that care must be taken to properly treat runoff from the developed site. SEOTION 3 -INFILTRATION RATES/SOILS REPORT The National Resource Conservation Service (NRCSS) of Thurston County mapped the on-site soils as a combination of Nisqually loamy fine sand (74) and Spanaway gravelly sandy loam (110). Geotechnical explorations were performed by William Pameli, P.E. Soils Engineer. His report dated 7/10106 is included in Appendix.5. Alltest pits generally confirmed the NRCSS. soil designatigns:. Tha soils located on the Yidge/peninsula consisted ofsi Spanaway series, while theloWer elevation soils immediately adjacenttothe wetlands were wnslstent with a Nisqually designation. Aprevalent water table presence requires consideration for all drainage infiltration facility designs. SoA log test pitdata indicates that the highestwater depth was 62" below existing ground. To ensurethe pavement is not saturated by high water levels a minimum of 3 feet wlll be maintained beiweenthe high water level and the bottom of infiltration facility. Design infiltration rates will be dependent upon targeted soils the C-ftdrizon being the most desirable dueto their high permeability rates. The Nisqually series soils adjacent to thewet(ands revealed a shallow water table that generally makes these soils unsuitable fordreinace KPFF Consulting Engineers June 18,2007 ' Tahoma Tema Fairway Multi Family -Drainage Repon facilities. The recommendation of the soils professionals is to use an infiltration rate of between 6 and 20 inches per hour far C-hodzon soils dependent upon location: NI soil horizons had a minimum infiltration rate of 2.inches per hourbased on SCS seilsurvey information See attached soil evaluation report for more detailed infiltration- ' information. A design infiltration rate of 1 inch per hour will be used for infiltration calculations. ' SECTION 4-WELLS AND SEPTIC SYSTEMS The site is undeveloped and has no record of any well or septicsystems ever being built on-site. Thurston County has no records of existing or abahtloned septic systems on adjacent properties within 100 tt of the proposed infiltration facilities. Any septic systems found will be removed in accordance with Thurston County Department of Health Standards. City of Yelm sewer and water will serve the development. SECTION 5 -FUEL TANKS A review of the DOE's Leaking Underground Storage Tanks (LUST] list did not indicate the presence of any existing or abandoned fuel tanks on or near the project site. ' SECTION 6 - SUe-BASIN DESCRIPTION The project site is located within the Yelm Creek Drainage Basin per the Thurston ' County Comprehensive Map Mme. The proposed development is being treated as a single drainage basin for the purpose of this study. ' No handling of hazardous materials on this site is anticipated. SECTION 7 -ANALYSIS OF THE 100-YEAR FLOOD ' The site is found in FEMAfIRM panel 5303100001A. The majority of the Property is in zone X. This is an area determined to be outsidebf the 100-year flood plain. Small portions of the site along thesouth west property line lie within Zone. A. Zone A is area that has not been analyzedin detail but wrrespondsto the 100-yearfidodplain. ' However, local or spot floodingg,.if @ exists, usually is not shown on FEMA flood insurance maps, and especiallyif the source of Flooding is related to logging, development, or drainage modifcations since the date of the map, ARhoughthe ' Engineer is alert to the possibility of flooding from such sources, ft cannot be warranted that all areas subject to Flooding do or downyradientof the project site are represented on the map. A FEMA FIRM map is included In Appendix 3. ' SECTIONS-AESTHETIC CONSIDERATIONS FOR FACILITIES All disturbed pervious areas will be vegetated and landscaped during construction. A landscape plan will be submitted and approved prior to construction. ' SECTION 9 -FACILITY SIZING AND DOWNSTREAM ANALYSIS ' Detailed storm drainage calculations are included in Appendix 1 of this report. All on- site stormwater runoff will betreated, and infiltrated on-site. Since all stormwater will be infiltrated on-site, a downstream analysis was deemed ' unnecessary. ' KPFF Consulting Engineers 3 June 18,2007 I 1 1 1 1 1 1 1 Tahoma Terra Fairway Multi Family -Drainage Report SECTION 10 • COVENANTS, DEDICATIONS AND EASEMENTS Drainage faalities including the pervious pavement will require routine maintenance. The home owners associations or their assigned representatives will be responsible for all maintenance. The maintenance manual prepared for the project lists the maintenance requirements. See Part III -Maintenance Plan of this report. KPFF Consulting Engineers 4 June 18, 2007 i~~ i~ Part II Erosion Control Report Tehoma Terra Fairway- final Drainage Report 1 PART II -EROSION CONTROL PLAN SECTION 1 -CONSTRUCTION SEQUENCE AND PROCEDURE The proposed project will include an erosion Control plan designed to gontaih sih and- soil wthin the project boundaries-0udng wnstrudion until permanent vegetationand site improvements are in place..ErosioNsedimentation wntrofwill be aohievetl 6y a combination of structureUvegetatiortcov~r measures and construction practices tailoredto fit the she. Muddy cohstrucion equipment will not be allowedon the base material or the pavement. Best Construction Management Practices (BMP's) will be employed to propedy clear andgrede the site and to schedule construdion adwities. Before anyconstrtlctloh begins on-site, erosion control facilities shall first be installed. The planned construction sequence is as follows: 1. Install rock construction entrance. Use 4" to 8" diameter spalls withl2" minimum depth. 2. Install filter fabric fencing and construction fence where appropriate and as shown on the plans. 3. Clear site (grubbing and rough grading). 4. Designate an area for washing of equpment and concrete trucksto control the runoff and eliminate entry into the storm drainagesystems 5. Between November 1 and March 31, all disturbed areas greater than4,000 sf that are to be left unworked for more than twelve(12) hours shalfbe stabilized by one of the following: mulch, sodding or plastic covedng. 6. Install utilHies (water, sanitary sewer, power, etc.). 7. Install impervious wncrete, curbing, sidewalks and pour building pads. 8. Install pervious asphalt. 9. Landscape and/or seed all disturbed areas. ~ 0. Maintain all erosion control facilities until the entire site is stabilized and silt runoff ceases. Pervious asphalt system shall be installed toward the end of the construction activities- to minimize sediment problems. The subgrade can beexcavated to within six inches of final grade and grading wmpleted in later stages of the project. SECTION 2 -TRAPPING SEDIMENT dune 1B, 2007 Filter fabric fencing will be installed wherever runoff has the potential to impact downstream resources. This shall include the areas along downstream property lines. Dudng construction, theContradtorwill also be requited to install filter fabric fencing as needed, and as directed by the Engineer and/or theCity of Yelm. Stabilized construction entrances will be installed'to prevent vehicles from tracking soil away from the site. All disturbedlexposed soils shall be covered with straw or mulch to prevent erosion in these areas. The Contrector will notbe allowed to leave diaturtied areas greater than S,000sf (that are to be left unwgrked for more than twelve (12) hours) uncovered during the rainy season from November 1 through March 31. Mulch, sodding or plastic covering will be used to prevent erosion in these areas. Erosion and sediment control shall be strictly controlled during and after construction. Care shall be taken to not track sediment onto pervious pavement. Engineers ' Tahoma Terra Fairway -Final Drainage Report SECTION 3 -PERMANENT EROSION CONTROL S, SITE RESTORATION ' All disturbed areas will be paved,.covered with a building, or landswpedwith grass, shrubbery or trees per the development plans. Special attention shallbegiven to areas adjacent to pervious pavement surfaces. Any exposed soil shall be mulched, planted, and otherwise stabilized as soon as possible. ' SECTION 4 • GEOTECHNICAL ANALYSIS AND REPORT ' See Appendix 5 for a complefe soil evaluation report. There are no slopes exceeding 15- percent, therefore a geotechnicel report for slope analysis was deemed unnecessary. ' SECTION 5 -INSPECTION SEQUENCE In addition to City inspections, the Project Engineer shall inspect the facilRies related to ' stonnwater treatment, erosion control, storage andconveyance during construction. At a minimum, the following items shall be inspected at the time specified: ' 1. The erosion control facilities should be inspected before the start of clearing and grading to ensure the following structures are in place: a. Construction Entrance b. Filter Fabric Fences ' 2. The conveyance systems will be inspected after construction of the facilities, but before project completion to ensure the following items are in working order: a. Pavement Drainage ' b. Roof Drain Piping 3. The erosion control and conveyance items listed above shall be inspected as t soon as practical following every significant rainfall event (2-inches in a 24-hour period) that occurs during construction. 4. The permanent site restoration measures shall be inspected after landscaping is completed. 5. A final inspection will be performed to check final grades, settings of control structures and aU necessary findings to complete the Engineer's Construction ' Inspection Report Form. This form must be completed prior to final public works construction approval. SECTION S -CONTROL OP POLLUTANTS OTHER THAN SEDIMENTS ' Washout from conaefe trucks shall not be dumped into the storm drain, or onto soil and pavement, which carries stormwater runoff: It shall be dumped into a designated ' area to be later backfilled or hardened and broken up for disposal into a dumpster. The Comractor is required to designate a washdown area for equipment and concrete trucks well away from pervious pavement. KPFF Consulting Engineers 6 ' June 18, 2g07 ' Tahoma Terta Fairway -Final Drainage Report 1 1 t 1 1 1 ~ Part III ~ Maintenance Plan ' Tehoma Terra Fairway -Final Drainage Report PART III -MAINTENANCE PLAN ' SECTION 1 -REQUIRED MAINTENANCE '' The on-site storm drainage facilities will require occasional maintenance:. Thefollowing is based on minimum requirements as set forth in the Drainage besign'antlErosion, Control Manual of Thurston County. The required maintenance and frequency of maintenance are as follows: ' The following pages contain maintenance needs for most wmponents that are part of the drainage system, as welt as for some cemponents thaflire not. Ignore the ' requirements that do not appty to this system. A checklist should be completed for all system components according to the following schedule: 1. Monthly from November through April. 2. Once in late summer (preferably September). 3. After any major stone (use 1" in 24 hours as a guideline), items marked `S° only. ' Using photocopies of these pages, check off the problems identified with each inspection. Add comments on problems found and actions taken. Keepthese "Checked" sheets in a file, as they will be used to write the annual report (tlue in May ' of each year). Some items do not need to be looked at every time an inspection is done. Use the suggested frequency at the left of each item as a guideline for the inspections. ' The City of Yelm is availablefor technical assistance. Do not hesitate to call, especially if it appears that a problem may exist. 1 1 1 KPFF Consulting Engineers T ' June i8, 2007 ' Inspection Period Number of Sheets Attached; ' D I d nspecte ate : ' Name of Inspector. Inapectais Signature: 1 1 1 1 1 ATTACHMENT "A": MAINTENANCE PROGRAM COVER SHEET ATTACHMENT"A" 1 1 1 1 1 1 Maintenance Checklist for Grounds (Landscaping) Frequency Drainage Req d Problem Conditions to Check Conditions That Should System For Exist Feature M General Weeds Weeds growing m Weeds present in less (nonpoieonoue) more than 20% of the than b% of the landscaped area (trees landscaped area. and shrubs onl M Safety hazard Any presence of No poisonous vegstation poison iry or other or insect neatepresent in poisonous vegetation landscaped area. or insect nests. M.S. Trash & debris Dumping of yard Remove trash and debris buildup in wastes such ea gresa and dispose ae open apace clippings and prescribed by City Waste branches. Unsightly Management Section. accumulation of non- degradable materials such as glass, plastic, metal, foam and coated a er. M Missing or Any defect in the Fence ie mended ar broken fence fence or screen that shrubs replaced to form parts/dead permits easy entry to a solid barrier to entry. shrubhe a facili M.S. Erosion Erosion hoe resulted Replace soil under fence in an opening under a so that no opening fence that allows exceeds 4" in height. entry by people or Causes of erosion pets. identified and steps taken to slow down and/or spread out the water. Eroded areas are filled, contoured, and seeded. M Unruly Shrubbery is growing Shrubbery is trimmed vegetation out of control or is and weeded to provide infested with weeds. appealingaeethetics. Do not use chemicals to control weeds. A Trees and Damage Limbs or parts of Trim treee/ehrube to shrubs trees or shrubs that restore shape. Replace are split or broken trees/shrubs with severe which affect more damage. than 25% of the total foliage of the tree or shrub. M Trees or shrubs that Replant tree, inspecting have been blown down far injury to stem or or knocked over. roots. Replace if several damn ed. A Trees or shrubs w}uch Pace stakes end rubber- aze not adequately coated ties around young supported or are treealehruba for support. leaning over, causing exposure of the roots. ' If you are unsure whether a problem exists, pleeee contact the CITY and oak for technical asaiatapce. Comments: Key: A=Annual (March or April preferred) ' M =Monthly (see schedule) Q =Quarterly S =After major storms 1 t Maintenance Checklist for Pervious Asphalt Pavement Frequency Drainage Req'd Problem Conditions to Check For Conditions That System and actions to take Should Exist Feature M,S Pervious Sediment Ensure that the pervious Sediment is removed Pavement Buildup on pavement surface ie free and/or pavement is surface of sediment cleanedeq Eliot infiltration works actor ~. to de ~ n M,S Pervious Sediment Ensure that the Sediment ieremoved Pavement Buildup on contributing and adjacent and/or pavement ie Surface landscape areas are cleaned eo that stabilized and mowed infiltration works with cli ~ s removed actor ' ;tb des' Q Pervious Sediment Vacuum sweep porous Sediment is removed (4 times/yr Pavement buildup on pavement surface followed and/or pavement is minimum) surface/ by high pressure hoeing to cleaned so that preventive keep pores free of infiltration works maintenance sediment accordin to deli Upon Pervious Spot Clogging Prolonged spot ponding on No prolonged ponding. Failure Pavement pavement surface. Drill Infiltratiosworke half-inch holes through according to design. avement eve few feet. ' If you are unsure whether a problem exists, please contact the CITY and ask for technical assistance. Comments: ' Key: A =Annual (March or April preferred) M =Monthly (see schedule) Q =Quarterly ' S =After major storms 1 1 1 i~ 1 1 1 N 1 7ahoma Terra Fairway -Final Drainage Report SECTION 2 -RESPONSIBLE ORGANIZATION The Home Owners Association or its assigned representative shall he responsible for the operations and maintenance of alt onsite storm drainage facilNies. SECTION 3 -VEGETATION MANAGEMENT PLAN All disturbed pervious areas on the site will he landscaped to provide an aesthetically pleasing environment and to control sediment distribution. SECTION 4 -SOURCE CONTROL Warning signs shall be posted indicating the nature of the pervious pavement surface and warning against resurfacing the site with conventional pavement orthe use of materials which could affect the inrittration capacity of the surface. KPFF Consulting Engineers June 18,2007 12 Appendix 1 Storm Drainage Calculations DRAINAGE CALCULATIONS ' The following calculations are based on the requirements contained in the 1992 Washington State Department of Ecology (WSDOE) Stormwater Management Manual for the Puget ' Sound Baein. DESIGN AND BASIN INFORMATION SUMMARY: Soil Classification SCS SoIl Classification: Spanaway (110) ' Nisqually (74) Hydrologic Group: B Infiltration Rate: 2 inches hour ' SCS Runoff Curve Number: (Table III-1.3 WSDOE Storm Manual) Post-developed (Lawns, 7b%+graas cover): CN=80 ' Pervious pavement CN=80 Post-developed (impervious, roofs, pavement) CN=98 Rainfall Design Storms: (WSDOE Isopluvial Maps-App. AIII-L.1 of WSDOE Storm ' Manual) 6-month storm (64% of 2 yr. Storm) =1.28" ' 2 yr./24 hour storm =2.0" 10 yr./24 hour storm =3.tY' 100 yr./24 hour storm =4.0" 1 1 1 1 1 Post-Developed Basin Area Summary Tributary Lot Impervious Area 0 27 Ac sidewalk . Disturbed Pervious and Undisturbed Pervious 3.43 Ac rasa/landsca in _ _ _ Pervious Pavement 1.04 Ac Directly Connected Impervious Area 0 58 Ac roof area . _ Total 5.32 Ac The Baein summary conservatively assumes that all undiaturbed/landacaped area onsite is tributary to the pavement. In reality some undiaturbed/landacaped areas will independently infiltrate etormwater that will not be directed to the pervious pavement. DETAILED CALCULATIONS: Stormwater Treatment: Pervious Pavement will provide the treatment for the stormwater. StormShed software was used to model the runoff. Sizing Calculations: 1 See the following StormShed software modeling peak output for the design storm event: Design Storm (24 hour) Peak Output Q(6-month) 0.167 cfa (2 .) 0.564 cfa _. Q{lO yrJ _ 1.321 cfa Q(100 yr.) 2.200 cfa ' Pervious Pavement: ' The 1992 edition of the WSDOE Stormwater Management Manual and the Low Impact Development Technical Guidance Manual (Puget Sound Action Team, 2005) were used to size the base course for the pervious pavement. The calculations were based on the ' infiltration rate of 2-inches hour suggested by soil professionals after investigation of the site. The WSDOE Manual states that infiltration BMP's shall be designed to completely drain stored runoff within 24 hours fallowing the occurrence of the 6-month, 24 hour design storm and 48 hours following the occurrence of the 100 year, 24 hour design storm. The Darey's Law approach ie used to demonstrate sufficient capacity and drawdown time of the pervious pavement base/reservoir layer. ' Q=f *i*A, where ' Q= flowrate at which runoff is infiltrated by soil underlying base course f=infiltration rate o£ soB or infiltration media t i= hydraulic gradient A= surface area of BMP ' A factor of safety of "two" was applied to the recommended design infiltration rate of 2 in/hr, thus f=2 in/hr * 0.5 = 1 in/hr = 0.042 ftlhr ~ „1 1 r = D.o83 Pt~tir- The hydraulic gradient is shown by the equation: ' where h is the height of the water column over the infiltration/filtration media and L is the For design purposes hydraulic gradient i was set equal to 1, which made discharge ' independent of stage. 1 distance from the top surface of the BMP to the water table or impervious layer L = assumo 3 feet 1 ' According to StormShed the 100-year/24-hour storm event will result in peak volume of 45,138 cf. The design void percentage for base rock is 30%. The pavement area is 1.04 acres = 45,300 sf. ' At facility base: A=46,300 af; Q(a) _ (0.042 * (0+3)/3) * 45,300 = 1902.6 ef/lrr ' Assuming infiltration rate by bottom area only; 1902.6 ef/hr *24 hra = 45,662 cf. Thus the pervious pavement and underlying soils will have the capacity to ir$Itrate 46,662 ' of per B4-hour period, which greatly exceeds the 6-month/24-hour event volume of 6,035 of and exceeds the 100-year/24-hour event volume of 45,138 cf. ' In the case of an event larger than the 24-hour/100-year storm or if the pervious asphalt fails, excessive runoff will flow to the westerly points of the drive aisles and release to the landscaped area in the wetland buffer. ' The StormShed calculations that follow show that the peak stage for the 100 year event was 0.347'(4.2") above the base of the storage area. Therefore a base course of 4.2" would be adequate for temporary reservoir storage. However a minimum base course of 14" is recommended in order to provide adequate strength to the wearing course and to minimize the risk of asphalt failure due freeze damage or saturation damage of the top course. The ' designed pavement section includes 14"fractured rock base material lined with geotextile fabric, and 3" pervious asphalt top course. See appendix 2 for a pavement section detail. 7 i ~lll~-/~-Gl>/~h~Calp~~z,}~~,~c~rSi,a<h•,c~-Id,~s~_ ~«~~rz~iv, (J~ !7' l ~~~' ~ ~r ~~ /U~ i,drriZ l/"u- / of tyt~ ~~,~~ N C~L'~ a I'~i'c`~ S ~ o .~: ¢_ ~`l ~~,1 f 6jSC~ . 1 1 1 1 1 1 TEMPORARY SEDIMENT TRAP CALCULATIONS The following calculations are based on the requirements crontained in the 2001 Washington State Department of Ecology (WSDOE) Stormwater Management Manual for the Puget Sound Basin. DESIGN AND BASIN INFORMATION SUMMARY Soil Classification SCS Soil Classification: Spanaway (110) Nisqually (74) I~ydmlogic Group: B Infiltration Rate: 2 inches hour PosbDeveloped Basin Area Suxrm~ary Basin A Basin B Tributary Lot Impervious Area 0 04 Ac 0 02 Ac sidewalk . . Disturbed Pervious and UndisturbedPervious 1.69 Ac 1.59 Ac aeallandsca in Pervious Pavement 0.46 Ac 0.53 Ac Direct)y Connected Impervious Area 0 37 Ac 0 22 Ac roof area . . Total 2.61 Ac 2.36 Ac ~'. The Basin summary conservatively assumes that all undiaturbed/landscaped area onsite is tributary to the pavement. In reality some undieturbedflandscaped areas will independently infiltrate stormwater that will not be directed to the pervious pavement. DETAILED CALCULATIONS: Temporary Sediment Traps will provide the treatment for the stormwater during construction. Western Washington Hydrology Model (W WHM) software was used to model the runoff Sizing Calculations: Design Storm (24 Hour) Basin A Basin B __ ___.- Qzy. _ 0.2231 cfa 0.1979 cfa 1 1 1 Surface Area of Temporary Sediment Trap M = FS z (QzN.) where: FS =Factor of Safety = 2 for nen-ideal settling A, =Surface Area Qz =Flow rate (cfs) V. =Settling Velocity of sediment = 0.00096 ftlaec Therefore, the surface area equation becomes: A. = 2 x (Qz/0.00096) Using the Ilow rates calculated by W WI3M produces the minimum surface area required for each drainage basin. Baain A Minimum Surface Area Reouired A, = 2 x (0.2231/0.00096) = 464.79 ftz Basis A Surface Area Provided A. = 695.69 ftz Basin B Minimum Surface Area Required A. = 2 x (0.1979/0.00096) = 412.29 ftz Basin B Surface Area Provided A, = b64.45 R° Appendix 2 Drainage Plan F F F F F I ~ ~~. ' ~ F F F F F O ~~~~I ~ ~. g~~Q & F f gg ,,~ r ~~E i ~~ ° c i ~~~ ;. F k k ~. k /~ ~ _ ~ ~~~ ~. F ~ ,. 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O ~ ~ v flq s_, od'g ___ / ~'~.~ o°` b° ( / ,' Y N $ C F ~ tl / ' '.i y Mk~ ~ ~° ~9 ~ \ ~ ~~ ' ~ ~ °`, ~ ~, ° ~ _ _ ___ag-t~F~~. , ~° ° ~ i 4 ~a ~ .. ~ ~ ", S ~A ~ , y r~i 4 ~ ~~`=L 8A o o ° ~ ~ ~ ~ F ~ ~~ ~~ ~ ~~ . ; a _ .~ F ~ ~ 45 yf7 l -_ \~~ n2 ~~ ,~ ~ I~ °~~~: F ~ ~ ~~ Vf ~ ~ °° li ~ F ~~~~~ ~ ~~o~~: p~a 1 f ~ ~~ 1 ~ np~ / ~ ns-~ C N ~ G~\ \~~ ~F I ~ ~~ ,f% 6 ~ ~~ ~~~ ~ ~ ~~ ~~ i ~~ t ~ .,~~ ~ V ~ t / ` ~G~ ~` ° ~ a~ ~a ntNmvn~rrnuW ~tnnw~rfrouauio ~ GRADING 8 DRAINAGE PIAN mF~" ~ _ ~ A aum-nn Appendix 3 FEMA Map N O m - - x - - -- o o ~ a O f D -i m r ` N 3 p N Z I n BURNEfT y. N a < O 2 m D a p a q3'~: 38.x' Q~S -_ H 3 ~ `~~~° 3 ~ s 3 ~Y~~~ e+ • o 3g3Pg - a 9 c~ yC•0 x~ ee A ~ D' ~ a ~ 3 ~ yn H T • Z- -~ d ~3~s' ~ _ 9 .'~ni . o ~ e ~ k~ g g a m +~ ~ A 0 _ ~ ; °ogg m5 ~ ~ ye '3 C 2 m -~i 9 yym O O CAL Z ~ ~n _ y B T $ ~ ~-I ' is}'9n 3 m S - '~ H T fn s3 iu i y - O 8 ~n .a ~~~g t YQ 2 m m Y'C _ 3 S 9 3 $ga3 n 3 33~~ ^° ~ ~. i i 1 i Appendix 4 Facility Summary Forms I 1 I THURSTON COUNTY REGION FACILITY SUMMARY FORM Complete one (t) for each fadlity (detentionlretention, coalescing plate filter, etc.) on the projed site. Attach 8 1l2 x 11 sketch showing location of facility. Proponent's Facility Name or /dent~er (e.g., Pond A) ..............: Pervious Pavement Name of Road or Street to Access Facility :...................... N/A Hearings Examiner Case Number ............................ . Development Rev. Pmject No.rBldg. Permit No .:................ . Parcel Number ............................................ 78640000009 To be completed by Utility Stall: 'UMity Faulily Number Project NpinLier (nom) :Paroel N6n{bef Statw..(num, tch) 0, Known,fl Public$2 Unknown; ~3 Unassigned Basin and Sub basin. (num, 6ch) `: (2ch for basin 2ch far sub basin, 2ch future Responsible CITY (alpha, 1ch) PaR 1 -Project Name and Proponent Pmject Name ................................ Project DEVELOPER ........................ . Project Contact .............................. Address ......................... .......... Phone ...................... ... ...... ...... Pmject Proponent: (il different) .................. Address .................................... Phone ........ ................ ... .......... Project Engineer ............................. Firm ................ ..... ............ ...... Tahoma Terra Fairway Tahoma Terre Doug Bloom P.O. Box 627, Rainier, WA 98667 (380) 95t-7568 Same Same Same Clinl Pierpoint KPFF Consulting Engineers 360-292-7230 Part 2 - Proied Location Section(s) 24 Township 17 Range t E, Willamette Meridian Part 3 - Tvpe of Permit Application Type of permit (e.g., Commercial Bldg.): Residential Bldg Other Permits (circle) ^DOFNVHPA ^COE Wetlands ^FEMA ^Shorelina Mgmt ^Encroachmenf ^NPDES ^Other ^COE 404 ^DOE Dam Sa/ety ^Fbodplain ^ROCkeryiRefaining Wall ®Gmding Other Agencies (Federal, State, Local, etc) that have had or will review this Oreinage Erosion Control Plan: 1 Part 4 -Proposed Project Descriation ' What sheam basin is this project in (e.g., Percival, Woodland)...... .. Yelm Creek Project Size, acres .......... ............................ .. .. 5.04 Ac Zoning ................................................. .. MPC Od-site: Residential Subdivision: Number o/Lots :........................ .... 1 Lot size (average), acres :................ Building Permrf /Commeroial :............ . .... Building Footprint, acres :................. ... O.SB Concrete Paving, acres ::................ ... 0.06 G2vel SuAace, acres ::.................. .. . ' Lattice Block Paving, acres :.:.............. .. . - Porous paving, acres 1.04 Public Roads (including gravel shoulder), acres :............ .. - Private Roads (including g2vel shoulder), acres :.......:.. .. . Onsite Impervious SuAace Total, acres:........... 0.64 ' Part 5 -Pre-Developed Project Site Characteristics Stream through site, y/n: ...NO Name: .................................... ........ ..N/A DNR Type: ................................... ....... ..N/A 1 Type of feature this /acility discharges to (i.e., lake, stream, intermittent stream, Groundwater pothole, roadside ditch, sheettlow to adjacentpdvate property, etc.): Infiltration info ground, y/n :............ .... ............... Yes Swales,Ravines,Y/n ::.. .............................. No Steep slopes (steeper than 15Y) y/n:......... _......... No Erosion Haiard, Y/n :.......................... No ......... 100 yr. Floodplain, y/n :....................... Yes Lakes or Wetlands, y/n :............................ Yes SeepsSpnngs,Y/n ::.................................. No High Groundwater Table, y/n :............. ... ....... Yes Wellhead Protection or Aquifer Sensitive Area, y/n:. ......... Np 1 i 1 1 1 1 Part 6 - Facililv Description -Pervious Pavement Total Area Tributary to Facility Including Off-site (acres) :..:.. . .: ..... 5.32ac Total On-site Area Tributary to Facility (acres) :..:............ ...: 5.04 ac ' Desgn Impervbus Area Tdbutary fo Facility (acres) ............ .... 0.6& ac Design Landscaped Area Tributary )o Facility (acres) :......... . .... 3.23 ac Design Total Tdbutary Area to Facility (acres) :................ ..... 5.32 ac i Enter a one (1) (or the type of facility: ): . . Wet pond detention ........... .................... .:.. . _ Wet pond water surface area ..... ................... ... . Orypond detention .............. .... ....... ..... ' Underground detention ..... ......... ..... . ..... Infittmfion pond.. ~........, ...... .. ... ...... .. ... ..... Dry well infiltration ................:...........:... . .... . Coalescing plate separator ................ ......... . .... - Centd(uge separtor ............................... .... . Biofitter ........................:................ ..... Other............ (Pervious Pavement) 1 Outlet type (Enter a one (1) (or each type present) Filter ........................................... ..... Oil water separator ................................ ..... Single odfice ..........:........:................. ..... Multiple ori/ice .............................. . . . Weir ......................... ..............~.... ..... Spillway ..................... ......... ..... ..... ..... Pump(s) ..................:...................... _ .._ Other (Infiltration) .................................. ..... 7 ' - Part 7 -Release to Groundwater - Des(gn Percolation Rate fo Groundwater (i(applicable)............ 1 inch/hour I l 1 1 1 1 1 1 i ~ Appendix S Soils Evaluation Report r~ -~ ' SOILEVALUATION REPORT FORM 1: GENERAL SITE INFORMATION 1 PROJECT TITLE: Tahoma7erra Fa'uway SHEET:1 OFf SCA PROJECT NO.: 04104 DATE: 7/10706 PREPARED BY: VYrliam Parnell, P.E. - 1. SITE ADDRESS OR LEGAL DESCRIPTION: Longmtre Street SE Yelm, WA 98597 iPN: 70840000009 - 2. PROJECT DESCRIPTION: Create a mrllttamity subdvsion vrilh aA essoilated roadway, uBGly and WndscepGrg improvements. - - 3. SRE DESCRIPTION: The project site "s undevebped. Ske.[opography is slightly sloµng. A high paint ridgelpeninsrla located centraAy an the site lies in an east to west posifion. Generaly the she slopes away to the north, west and soutlr from tlrre ddge. Ekvafiorrs range (ram a high of 338 R on the described ridge to a bw of 330 R abng Ore nortlrwestem property Gne. Sde vegeta8on. cons's6 of patches of uncropped pasNre grosses and indigenous bntah amongst a medium density dedduous and conifer forest The project site is botndedby Thompson Creek and associated we8ands to the north, west and south, and by the Tahoma Terra Gatl & Counhy Club to the east. On-site sots are a combina8on ofwell-drained Nisquafiy and Spanaway series safis formed in glacal oulwash. 4. SUMMARY OF SOILS WORK PERFORMED: Nine test pits were excavated by trackhoe to a maximum depth of.768' below exis8ng grade. SoAs were hlspected by entedng and v'sualy logging each test ptt to a depthof four feet. SoAs beyond four feet were inspected by examtrdng backhoe faG'mgs. Soli log test pit data sheets are inchrded in 1tGs report. 5. ADDITIONAL SOILS WORK RECOMMENDED: AddNOnal soils work may be necessary, dependent upon site-specific drainage design parameters: 6. FINDINGS: The Nafional Resource CarreervaOon SeMce (NRSC) of Thurston County mapped the otrslte sops as a combination of a Maqualy bamy fne sand (74) and a Spanaway gmveAy sandy loam (110). Aq test piN generaly confirmed tlrese deslgna8ors. The sots located on Me ddgelpeninsWa catrsisted of a Spanaway seder, wM1e the lower elevation sole immediatety adjacent to the wetlands were consisterd with a Nisqualty designation. Watertable was present m all test pits. 7. RECOMMENDATIONS: The tipanaway sob seder b a somevha[ excessively drained soil that formed in gladal oulwasll. Infltraton rates are generally rapid b the substratum saik. The substraum soils shodd 6e targeted for aA drainage infltrafion facANes. A prevalent water table presence requires corrsiderofion for aA drainage InfiBraOon faa5ty designs. Design fnHtraBon rotes wit be dependent upon targeted soils, the Cfior¢on so0s being the most desirable due tp thetr high permeability rates. The Nisqualty soil series is also a somewhat excessivey drained sill that formed in glacial oulwash. Infiltration rates are generaAy moderatety rapid in the substratum soils. However, test pits in the vicitdty of Ore NkquaAy seder soils reveabd a shallow water table that generay makes these soils unsrGtable for drainage GrfiMaBon faalilies. - Outing construcfion, care must be taken to preventerosion of exposed soils. Drainage facility - krfiltratbn rotates must be prapedy protected from cwdamina8on by the fine-grained upper horizon sots and from compactran by site construction ac8vi0es. Soils net properly protected wit cause drainage kifltradon (ac38es to premaNrety hN. I hereby cerfity that I prepared this report, and conducted ar supervised the performance of related work. I cerfity tlrat I am qualified to.do this work. I iepreseM my work to be complete an accurate wOhN the bounds of. uncertainty inherent to the practke of soils silence, andto be suitable for its intended use. - - - SIGNED: DATE: DRAFT i 1 Horz Al A3 C1 Cgm2 1 f SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terta Fairway PROJECT NO.:SCA 04104 SHEET: 1 OF 9 PREPARED BY: Wgiam Pame/, P.E. DAB, T/6/O6 SOIL LOG: i1 LOCATION: As per the attached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Nisqualty Loamy Fina Sand Tertace (7a) 4. DEPOSRION HISTORY: - 5: HYDROLOGIC SOIL 6. DEPTH OF.SEASONAL HW: Sandy Glacial Otrhvash GROUP: Unbrown B 7. CURRENT WATER e. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: UiYER: Level ~° - 70' _ 10. POTENTIAL FOR: EROSION RUNOFF PONDINO Stlght Slow Minimal 11. SOIL STRATA DESCRIPTION: See Falbwing chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS 8 RECOMMENDATIONS: Light mottles were pres 48" ' ent et 36° increasing to heavy mottles at . Sotla were wet at 66 and a static water level was present at 62" below the erisfing grade The C2 hodzon was very hard and exttemety manganese stained. . De pl Cobr Te re D'- E - 70Y0.32 ImVFSa E- 23' 10VR42 LmFSa zs•- na tarasre ImFSe 49'-]0' 10YR511' MSa ]0'-96' f0YR1H Grvilh CSe e'vMer lrup Soils Strap Description Soil Log it %CL %ORG CF SCR <10 <5 q ~ 158K <10 <a Mas <m 9 Mas 2 <10 SG <5 - ~] Mas -DRAFT MOT IND CEM ROO <p - M b6 - - H 23 F1F - ry 28 Map - - - ,~ - Sa sir - - FSP 2 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terra Fairway PROJECT NO.: SCA 04104 PREPARED BY: Wil5am Pame9, P.E. SHEET: 2 OF 9 DATE: 7/6/06 SOIL LOG: #2 LOCATION: As per fhe attached map. 1. TYPES OF TEST DONE: 2. SC3 SOILS SERIES 3. LAND FORM: None Nisqualy Loamy Fine Sand Terrace iT4) 4. DEPOSITION HISTORY: & .HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Sandy Gladal Otdwash GROUP: Unknown B 7:.CURRENT WATER e. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: LAYER level 140' Greater Than Bottom Of Hola - 10. POTENTIAL FOR: EROSION RUNOFF PONOING SWght Slow Minimal 11. SOIL STRATA DESCRIPTION: See Followng chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS 8 RECOMMENDATIONS: The C1 horizon was mo ° derately dense. Moderate mottles were presets at 88+ , Soils were wet at 136' and a static water level was presets at 140' helow the eristlng grade. ~ c_i« iaxwre. 0'- 10'- -f0YRa2 Satin 10'- 30' 70YR4/3 LmFSa 31"- 98' l0YRM9 MSa 99"- Se' 10YR6ra ExGrCSa 5a'- 9a' 10YR611 FxGrSCOb CSa 9S-14P t0YR62 GrFSa 1q0'-180' tOYR?/1. - FiGrM-FSa Soils Strata Description Soil Log #2 %CL %ORG CF 5 R MOT IND CEM ROO <X> FSP <16 ~5 <f0 Gr - - - ml 23 2 <10 -_ <f0 Mas - - - (m 2~ 4 <6 - <6 Mae - - a >~ >p <1 - <es sc - rc >zo >ao ~1 - <eo sc cm - - rc >zo >qo <5 - <26 SG F1F- - rc 620 - C2D `5 - <97 _ Mas - Sir str - >T1 - DRAFT SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terta Fairway - SHEET: 3 OF 9 PROJECT NO.iSCA 04104 DATE: 7/6/06 PREPARED BY: William Pamel, P.E. SOIL LOG: Y3 LOCATION: As per the attached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway Gravelly Sandy Tertace Loam (1 t0) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONALHW: Glacial Oulwash GROUP: ~ Unknown B 7. CURRENT WATER - 8. DEPTH TO IMPERVIOUS. 9. MISCELLANEOUS: DEPTH: LAYER: Level 132' Greater Than Bottom Ot Hole ill. POTENTIAL FOR: ~ EROSION RUNOFF PONOING SIigM Slow Minimal 11. SOIL STRATA DESCRIPTION: See Followng chart A2. SITE PERCOLATION RATE: See FSP 73. FINDINGS & RECOMMENDATIONS: Moderate mottles were " present at 73+•, Soils were we[ at 130 and a static water level was present a[ 132" bebw the etleling grade. Roots were present to 66". Horz De°N Colbr TexWre Al 0-- T t0YF232 SaLm A2 T- 20' 1P/R42 GraaLm Rwt 24'- Ca' 10YR43 CxSaLm C1 Ge'- SS 10YR1a GrtmCSa C2 66-- 93' 10YRN8 E>aGrCSe C3 93'-tea- tOYR~W1 FxGrM{Sa Soils Strata Description Soil Log #3 %CL %ORO CF STR MOT 95 <$ <f0 Gr - <ta -, <15 Gr - <15 - <2S 1aBK - <10 <30 SG - <1 - <95 SG C2D <2 - cap SG C2D I~p CEIw ROO <X> - H 2-9 - - mm 26 - - mm 2.6 - Im 620 - >N - - - 620 DRAFT FSP 2 2 3 >15 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Tena Fairway PROJECT NO.: SCA 04104 SHEET: 4 OF 9 PREPARED BY: WlNiam PameN, P.E. GATE: 7/6/06 SOIL LOG: M't LOCATION: As per the atlached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Nane NisquaNy Loamy Fine Sand Terrace (74) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HIN: Sandy Gleaal Oulwash GROUP: Unknown B 7.. CURRENT WATER 8. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: LAYER: • Level 96 . 93" 10. POTENTIAL FOR: EROSION RUNOFF PONDING t 1. SOIL STRATA DESCRIPTION: See Fallowing chart SIigM Slow Minimal 12. SRE PERCOLATION RATE: See FSP 13. FINDINGS 8 RECOMMENDATIONS: UgM mottles were r ts t 5 ' p ese a 6 increasing to moderate mottles at 66°. Heavy seepage was present et 96" below theeaisgn rad Th C4 hard and extremety manganese stared. g g e. e hodmn was very Soils Strafa Description - Soil Log #4 Die tlJ Cobr TeaWre %CL %~O G CF. ST~3 MOT IND CEM ROO cX> FSP O'- 4' 2.SY3rd ImVFSe <f0 <S c3 1SBK - - - R 2E 2 4-- f2 17- 4f' 41'- 62' 25Y4/3 f0YR3f3 10YR313 LmVFSa ImVRSa LmM$a q0 - <3 Mas cte <3 Mes <] <10 Mas - F1F - - - a - mf - - za 2-a am z 2 - B2'- ]2' t0YR45 C-MSe 2 - c30 SG C20 - - >20 ]2- 93' 10YR5/1 EKGrCaa <1 - <9S SG C2D - - >p - 93'-133' 10VR~/1 FX(`ir5i[TIN) <a <]p Nga ~p M~ - - Str DRAFT f 1 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terta Fairway SHEET: 5 OF 9 PROJECT NO.:SCA ON04 DATE: 7/6/06 PREPARED BY: WAAam PameA, P.E. SOIL LOG: Y6 - - LOCATION: Asper the attached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LANG FORM: None NisquaAy Loamy Fine Sand Tertace (74) 4. DEPOSRION HISTORY: 5. HYDROLOGIC SOIL ~ 6. DEPTH OF SEASONAL HW: Sandy Gladal Oulwash GROUP: Unknown 8 7. CURRENT WATER 6. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: LAYER: Lever - 69' - Grea[er Than Bottom Oi Hole 10. POTENTWL FOR: EROSION RUNOFF PONDING SIigM Slow Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS 8 RECOMMENDATIONS UgM moWes were present at 38' inaeashg to moderate mottles at 43'. Static water level was presets at 69' below the erisgnggrade. Hors De tp_h Color Texnre of o^- a iovRVt saLm A2 G- 16' teVR32 Salm A3 78'-30' f81'R4/t imVFSa C1 30'- SP 10VR31a LmFSe C2 So'-66' t0YR511 FSa C3 88'- 98' tOVRSIt ExGraa. Soils Strata Description Soil Log #6 %CL %ORO CF STR MDT MD <f8 6 <7 Gr - - <18 - - <1 1SSK - - <75 - <1 Mas - - <12 - - <t Ma F1F - t5 - b SG C2D - <3 - <]5 SG C2D - CEM ROO <X> - fl 2A - fl 2.6 - fl 24 - R 620 - - 'p _ - >p DRAFT FSP 2 2 2 8 ~. Horz A7 A2 ' A3 C1 C2 1 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terta Fairway - SHEET: 6 OF 9 PROJECT NO.: SCA 04104 DATE: 7/6/06 PREPARED BYi Wtltiam Pameq P.E. SOIL LOG: 76~ LOCATION: As per the attached map. 1. TYPES OF TEST DONE: 2. SCS 301LS SERIES: 3. LAND FORM: None Nisqualy Loamy Fine Sand - Tertace nb) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Sandy Gladal Oldwash GROUP:. ~ -Unknown B 7. CURRENT WATER 8: DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: - LAYER: Level 6g' Greater Than Sotlom Of Hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slow Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12: SITE PERCOLATION RATE: See FSP 13. FINDINGS 8 RECOMMENDATIONS: Light mottles were present a[ 36° Increasing to moderate mottles at 38". Solls were wet at 60' wtlh moderete seepage occluring at 70"below the eristing grade. Soils Strata Description Soil Log #6 DAM Cdw Teague %CL %ORG CF STR MOT IND CEM ROO <X> FSP G'- 4' 10VR4/2 trn cza d ct Gr - - - ry 2L 1 4'- 17 70VR5/! lm qa - q 1SSK - - - ry 2E 1 17-47 2.6Y52 LmMSa <g. <5 SG F1F - H .p. - 47- S/' 1P/R&1 VGrLSa q <80' SG L2D - ry >p 69"- ]9' 10YR5/1 LmMSa <a - q SG M3P - ry >p DRAFT SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION 1 PROJECT TITLE: Tahoma Terra Fairway - SHEET: 7 OF 9 PROJECT NO.:SCA 04104 DATE: 7/fi/08 PREPARED BY: William Pamel, P.E. SOIL LOG: #7 LOCATION: As per the attached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None ` Spanaway Gravely Sandy Terrace Loam (110) ~4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Oulwash GROUP: Unknovm B 7. CURRENT WATER B. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: L4YER: Level - 115° Greater Than Bottom O(Hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING SIigM Slow Minimal 1 L 801E STRATA DESCRIPTION: See Folldwing chart 12. SITE PERCOLATION RATE See FSP - 13. FINDINGS & RECOMMENDATIONS: Fan[ mottles were present a[ 94+° becomilg moderate a[ 98'. Sots were wet at 112° with moderate seepage occwdng at 115 ' below the existing grade. Roots were present to 72'. The C4 and C5 horizons were sightly to moder ately dense and extremely manganese stained ' Horz De Colo ie a r x ue Al 0'- 20' 7MR32 Setm Sw 20°- 26' 70YR43 VGrSaLm 'C1 2a--42 10YRY8 EM'xCSa ' c2 4Y- 6Y 10YRa2 FxGrCSa C3 63'- 56- tOVRa/e VGrCSa ' G. 9e--1211- t0YR2/1 F~GISa CS 120--1a0- 10YRT/1 Pea Gravel wAh CSa tNldef Soils Strata Description Soil Log #7 %CL %ORG CF STR MOT. IND CEM ROO <X> FSP' <1a c5 <3 - Gr - ~ - fl 26 2 <ts - <es sc fl ze z t3 - e]0. SG - - fl >20 >a0 d caS SG - - ff ~ >2f1 >a0 <t - ca5 SG F1F - - N >20 - q - <85 SG C2D -. - >20 - <1 - <gS SG C20 - >20. - DRAFT 1 Horz AI ' A2 Bw CI C2 C3 1 1 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: Tahoma Terta Fairway SHEET: 6 OF 9 PROJECT NO.:SCA 04104 DATE: 7B/08 PREPARED BY:, William Pamel, P.E. SOIL LOG: 08 LOCATION: As per the attached map. ' 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None - Spanaway Gravelly Sandy Tertace -. Loam (110)' /. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6- DEPTH OF SEASONAL HW: Glacial Oulwash GROUP: Unknown B 7. CURRENT WATER 6. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: LAYER: level 162° Greater Than Bottom Of Hole 10. POTENTIAL FOR: EROSION RUNOFF PONOING Slight Slovi Minimal 71. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS 6 RECOMMENDATIONS: Moderate mottleswere present at 107+'. Moderate seepage was presem at 162' below the epstlng grade. Roots were present to 42'. Soils were extremely manganese stained at 10T+. SoilsStrata DeSdiption Soil Log #6 De~dl Cobr Texture O'- 16' faVR711 SaLm ta' 33' 16VR32 GrSeLm 33'. 39' 10VRY3 VO[SaLm 38'- 64' feYRdB EaGrCSa 64"- 73- 10YR`W4 EvGM1mFSa ]3"-168' 18YRY1 ExGrCSa_. %CL %ORG CF STR 1b..2t j <1a <6 <10 Gr - <1a - ~0 Gr - <1a - e55 SG - <1 - cge SG <10 - <66 Mac - <1 - <ss sc c20 (ND CEM $OQ cX> FSP - n za z - - mm 26 2 - - Im 2-e .40 - a >zo >ao - - X20 8 - ~2n DRAFT 1 Harz ' Al 9w C1 C2 ' C3 1 1 SOIL EVALUATION REPORT FORM 2: SOIL LOGINFORMATION PROJECT TITLE: Tahoma Terra Fairway SHEET: 9 OF 9 PROJECT NO.: SCA 04104 DATE: 7/6/06 PREPARED BY: Wi&am Pamep, P.E. SOIL LOG: i5 LOCATION: Asper the aMached map. 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway Gravely Sandy Tenace Loam (110) 4. DEPOSRION HISTORY: 5. HYDROLOGIC.SOIL 6. DEPTH OF SEASONAL HW: Gladal ODNrash GROUP: - -Unlmown 6 7. CURRENT WATER 8. DEPTH TO IMPERVIOUS 9. MISCELLANEOUS: DEPTH: LAYER Level 14T GreatarThan Bottom Of Hole 10. POTENTIAL FOR: - EROSION RUNOFF PONDING SIigM Slow Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Heavy seepage was presem at 147° below Me existing grade. Roos were present to 48°. Soils were extremely manganese stained at 108'+,. Soils Strata Description Soil Log #9 P~ Cobr iwAUre %CL %ORG CF STR MOT IND CEM ROO IX> FSP 0-- 12 10VR3/2 GrSaLm <19 <9 <25 Gr - - - H 26 2 t7- ZS' f0YR9rJ VGrSalm <1B - - <qS SG - - - fm 2E 2 2E- 48" - 10VRNfi EvGrFSa <18 - <]0 SG - rya >~ >p 49--109' t0VR91 ExGrBCOb CSa e1 - =95 SG - - R >p. >dp t09--190' 10YR514 Grwilh CSa bnda <1 d9 SG C2D - >p - DRAFT 1 fl 1 Abbreviations Textural Class (Texture) Structure STR Grades of Structure Cobble -Cob Granular - Gr Stron - 3 Stone - St Bloc - Blk Moderate - 2 Gravell - Gr Plat - PI Weak - 1 Sand - Sa Massive. - Mas Loam - Lm Sin Ie Grained - SG Sil - Si Sub-An ular Blo - SBK Cla e - CI Coarse - C V -V Extreme) - Ex Fine - F Medium - M Induration 8 Cementation IND CEM Weak - Wk Moderate -Mod .Stron - Str Mottles MOT 1 Letter Abundance 1st Number Size 2nd Letter Contrast Few - F Fine -1 Faint - F Common - C Medium - 2 Distinct - D Man - M Coarse - 3 -Prominerit - P Roots (ROO) 1st Letter Abundance 2nd LetterSize Few -f Fine - -f Common - c Medium - m Man - m ,.., ..-- Coarse - c --•- ....,~a, o„ cu iauyc ~i nano auun ra[es nom JGS 5011 SUNey (<X>) FSP -Estimated Field Saturated Percolation rate based on horizon specific factors. _ ____ F ~- .. _. ... .. ssi .. .r.. • O - _ .. .. _ L .~ ../ ._ .. u .. _. _ .. ,_ .. _. .. ~. ._ :.. _. ... O .... .~ ..~.. __.. ..~. ..~ .... .~. ,u. .~ ++u ..._ ~ .v .I '.. r. ... .. - M .. ~~ ... ~ O --~ .. ,~ ,~ , -~' a o ~.; - ~ -,, ,. r-- ' ~ _ (5.040 acr ~ ~ J~ o \ ~ („~ _:~ o ..~. .~..~ - o. o p -, o 6_ o .. ~. ' .. ~' . p o _ _ I ' n Thompson Creek and u. ~ Q associated wetlands as delineated by the Coot .. ~ ~' ~ mpany in March of 2005. a i ...,. ,.,_ _, ..~. ,_ ... .W. w> ~_ .W ~~ . ~ w _ • o o! W !~_ _ .. . ~_ I. ~ ,; ~ ~ ~ ~ ~~R„S 1- - __._ _~ _- i LNM W IX9YS BY 7~ as as OLLV4 BY µgNFp Bf MR MHO LM hmre.9we 3O3 W I ~99903 s~p~ ~w vry. 5 C /. l G 1JL01232']290 Ia l9C0129$-R3~ SIGN lo[ u: M6o92o1 1•~ yp' i a i 1 1 1 ' Appendix 6 Maintenance Agreement 1 1 1 t 1 RESIDENTIAL AGREEMENT TO MAINTAIN STORM WATER FACILITIES TAHOMA TERRA PH. 3-8, LLC. ITS HEIRS, SUCCESSORS, OR ASSIGNS (HEREINAFTER"DEVELOPER") AND CITY OF YELM (IEREINAFTER "JURISDICTION") The upkeep and maintenance of etormwater facilities ie essential to the protection of water resources. The DEVELOPER is expected to conduct business inn manner that promotes environmental protection. This Agreement cnntaina specific provisions with respect to maintenance of on-site atormwater facilities. LEGAL DESCRIPTION: See Plat of Yelm Townhomea, Yelm, Thornton County, WA Whereas, the DEVELOPER has constructed improvements, including but not limited to, buildings, pavement, and atormwater facilities on the property described above. In order to further the goals of the JURISDICTION to ensure the protection and enhancement of water resources, the JURISDICTION and the DEVELOPER hereby enters into this - Agreement. The responsibilities of each party to this Agreement are identified below. The DEVELOPER shall: ' (1) Implement the etormwater facility maintenance program included herein ae Attachment "A". 1 1 t 1 1 The JURISDICTION ahaR: (1) Provide technical assistance to the DEVELOPER in support of its operation and maintenance activities conducted pursuant to ire maintenance program. Said assistance shag be provided upon request and as JURISDICTION time and resources permit, at na charge to DEVELOPER: (2) Conduct a minimum of one (1) Bite visit per year to discuss performance and problems with the DEVELOPER. - REMEDIES: {1) If the JURISDICTION determines that maintenance or repair work is required to be done to the etrom water facilities located on the awner/homeownera association property, the JURISDICTION ehaR give owner/aeseciationnf the property notice of the specific maintenance and/ot repair required. The JURISDICTION shall set a.reaaonable time in which such work is to be completed by persona who were given notice. If the above required maintenance and/or repair ie not completed within the time set by the JURISDICT[ON, written notice will be sent to persona who were given notice stating the JURISDICTION'S intention to perform such maintenance and bill ownet/homeownere association for all incurred expenses. The JURISDICTION may also revoke atormwster utihty rate credits if required maintenance ie not performed. ' (2) If at any time the JURISDICTION determinesthat the existing system creates any imminent threat to public health or welfare, the JURISDICTION may take immediate measures to ' remedy said threat. However the JURISDICTION shall also take reasonable steps to immediately notify either the property owner or the person in control of said property of such imminent threat m order to enable such owner or person in control to take ouch immediate ~ measures either independently or in cooperation with the JURISDICTION. (3) The DEVELOPER grants limited authority to the JURISDICTION for access to any and all ' atormwater system features for the purpose Of performing maintenance or repair or inspection pursuant to the terms of this agreement, t- (d) The persona hated in (1), above shall assume responaihihty for the coat of maintenance and repairs to the etormwater facility. Such responsibility shall include reimbursement to the JURISDICTION within 90 days of receipt of an invoice for work performed by the ' JURISDICTION m maintenance or repairing ouch facility pursuant to the terms of this agreement. Overdue payments will require payment of interest at the current legal-rate for Rquidated judgments. If legal action ensues, any costa or fees incurred by the JURISDICTIONwill be borne by the pazties responsible for said reimbursements. This Agreement is intended to protect the value and desirabWty of the real property described above and to benefit all the citizens of the JURISDICTION. It shall run with the ' land and be binding on all parties having or acquiring any right, title, or interest, or any part thereof, of real property. They shall inaure~to the benefit of each present or future sucmeaor in interest of said property or any part thereof, or interest therein, and to the benefit of aR ' citizens o£the JURISDICTION. IN WITNESS WHEREOF, this instrument has been executed 2 1 t Owner 1 t t 1 1 1 1 1 1 1 '- STATE OF WASHINGTON) ) 96 COUNTY OF THURSTON) I certify that I know or have eatiefactory evidence that (ialare) the person(a) who appeared before me and said person(s) acknowledged that (he/she/they) signed tMs agreement and acknowledged it to be (his/her/their) free and voluntary act for the uses and purposes mentioned in the instrument. Given under my hand and official seal this day of 200_. Notary Public in and for the State of Washington, residing in My commission expires: STATE OF WASHINGTON) sa COUNTY OF THURSTON) On this day and year above personally appeared before me, who executed the foregoing instrument and acknowledge the said instrument to be the free and voluntary act and deed of said Municipal Corporation for the uses and purposes therein mentioned and on oath states he ie authorized to execute the said instrument. Given under my hand end official seal this day of , 200_. Notary Public m and for the State of Washington, residing in My commission expires . APPROVED AS TO FORM: ' Appendix 7 Vicinity Map ~a~~ o~ /--~ o I ~ D ~~~~ 3 ~ -a r`n2 1 m ~ ~ m L 4 D `~ ~ Curant St 3 m ~5 o~~~ ~d a ~5/ 1 ~. ~1 a m 1 rT~ t 1 1 1 1 1 1