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21429 84TH AVE W.PDF111111111111 7910 21429 84TH AVE W 0 ADDRESS: 2&f- n)"ll TAX ACCOUNT/PARCEL NUMBER: 0037 ??�oO03 60 7 0 2- BUILDING PERMIT (NEW STRUCTURE): COVENANTS (RECORDED) FOR: CRITICAL AREAS:-O'?-000-,7- DETERMINATION: 0 Conditional Waiver F-1 Study Required Waiver DISCRETIONARY PERMIT #'S: DRAINAGE PLAN DATED: PARKING AGREEMENTS DATED: EASEMENT(S) RECORDED FOR: PERMITS (OTHER): PLANNING DATA CHECKLIST DATED: SCALED PLOT PLAN DATED: SEWER LID FEE $: SHORT PLAT FILE: SIDE SEWER AS BUILT DATED: SIDE SEWER PERMIT(S) #: GEOTECH REPORT DATED: STREET USE / ENCROACHMENT PERMIT #: WATER METER TAP CARD DATED: OTHER LOT: LID #: BLOCK: LATEMP\DS'Ps\F,orms\Strcet File Checklist.doc �_j rm� 84th Ave. W APPROVED AS AD erINEERING 7at e: - a GRAPHIC SCALE 0 15 JO 50 IN FEET 1 inch = 30 ft. CONTOUR INTERVAL 1 FOOT PROPERTYOWWER: ANNA MA TUSZEUSKI PROPERTYADDRESS.- 21429 84 TH A VE. W EDMONDS, WA SHING TON 98OJ6 TAXACC0b7VTANTPARCEL# 007J600300702 b Vl PP, E WO US S L TR FA CE CA L CS..' BUILDING J, 708 PA TIO 200 DRI"A Y 810 TOTAL 4,718 LOT AREA: 19,822 Sq. Ft. LOT COVERAGE: 7 4 4W. 6,94 3 -7 HEIGHT CALCS.: A. +94.75' B. +94.75' C. +9Z50' D. +9Z50' AVERAGE GR.4DE.- +96.125' �CTUAL = +120.125' MAXIMUM = +121.125' LOT SLOPE .037. "ain St Sw CD L gn 2121h S p 3- Z-2ft-WSW 221st 11 STREET FILE Zone 3 --- Corner Fla&, Setbacks Reauired Actual Front SidesYb 77-5- 7—.5-- Rear Odler —2--j 77-5-- APPROVED BY PLA INY 0 . . . ...... ....... SHEET TITLE: WCE V= A f" C- r'l RESUB MAR 19 2009 BUILDING DEPARUMENT CITY OF EDMONDS PLOT PLAN CLIENT: Tom Matuszeuski 21429 - 84th Avenue W Edmonds, WA. PLANNING DATA (N 11 STREET FILE 11 SINGLE FAMILY RESIDENTIAL Name: /V1 OJ S�kf Date: ------------ Site Address: Plan Check # -. 2_60c? c9O Project Description: /\ew 0 Reduced Site Plan Provided: NO) zorlifig Map Page: Corner Lot: (YES 00 Flag Lot: (YES Critical Areas Determination #: o on Ow -7 11 Study Required "-Waiver SEPA Determination: P—fkxempt El Needed (for over 500 cubic yards of grading) C1 Fee 0 Checklist C1 APO List with notarized form RequIre-W S�21backs Side: Street- 'Ve-- Rear: 2-S— -7. S_ Actual Setbicks Street: Side: L Sid Rear: Detached Structures: Rockeries: Fences[Trellises: El Bay Windows/Projecting Modulation: El Stairs/Deck: Height DatUfn Point: *6/7 u Daturn Elevation: 4_�, P - Maximum Height Allowed: Actual Height: ��_ - J ( ( - Other Parking Required: Parking Provided: 3+ Lot Area: 151 Maximum Lot Coverage: 35% Proposed:1 6. 7 Lot Coverage Calculations: AOL/ C�ra�e C-0 V4_rd ADU Created: (YES 100 Subdivision - Legal Nonconforming Land Use Determination tssued- (YES , i I -I- �, I Comments 14r,,171" I-( -, 16-(15- A-1 " f 3_��4 C q7- 'y ( �7:� Plan Review By: V. /-a k � Pldrm.q Data fo, m 04 -11,06.doc APPLICATION - �, 1 ST for � P F- r- - �!� n The City of Edmonds SIDE SEWER PERAHT EASEMENT No . .......................................... NEW CONSTRUCTION E] REPAIRS 0 324-06000 OWNER........... Hev ...... Xinfr.e-d .... C.a-rt.e-r ..................................... CONTRACTOR .................................................................................................. PERMIT No . ...................... ADDRESS ........ 2.1..4.2.9 .... 8..4.t.h ---- Av-e.n.ue .... W ...................................... LEGAL DESCRIPTION: LOT No . .............................................. BL()CK No . ..... ...................................... .. .. .. .. ...... .. .. ...... Ll 0 to 00 NAMEOF ADDITION ......................................................................................................................................... Dye Tested On Sewer 1972 Approved: DATE................................................ By ...................................................................... /1-/ -2 c7 December 2000 Page 614-17 Figure 6H-6. Shoulder Work with Minor Encroachment (TA-6) 77 mr FREE ILE A " I Note: See Tables 61-1-2 and 61-1-3 for the meaning of the symbols and/or letter codes used in this figure. 24 HR. NOTiCE REQ. FOR WSPE=ON 3 m `.i (10 ft MIN.:; OWNER/CONTRACTOR IS RESPONSIBLE r-OR EROSION CONTROL AND DAMAGE 'optionat) pplicant Mall repair/repiace all damage to., UtIftles or frontage Improvements in City 1/3 L right-of-way per CRY standards that is cause, occurs durinq the permitted project. A Typical Application 6 A . p DBY ENGMEERING Sect. 6H.01 PP 0 LO Fit C PER AT: Occupancy established by this certificate: No. Stories:— 2 Basement: Owner of building: Anna Matuszewski-.- The Sinc 1429 84" ile Family Residence at 2 e. of the 2006 edition of the International Residential Co the proposed occupancy is classified. By: �4RTIVIENT OF BUILDINGS MAL RESIDENTIAL CODE SECTION R110 ..—,Building P\qrmit M BLD2009-0041 Dwelling Units: Alt i,�, Type of Construction: VB 1 711 nspe�d and approved complying with the requirements adbpt6d1iy-the City'for-1hd group and division of occupancy and the use for which Issued this 5 th day of November, 2009 13 Chief Building Official Any change of occupancy or use requires a bdildinji permit and a now Certificate of Occupancy issued by the City of Edmonds Building Official. x EX. 6' WOOD FNC *7f �Knockout for 4"PVC Iff ,9 CONM4CTOR'S NOTES. 1. FOO71tVG 04fiVS-SHAL-EBE-DIRECTED- - bl-RYeCY TO THE INFILTRA77ON TRENCH. 2 ELEVA77ONS ARE APPROXIAM7E ONLY NERiCOMMCTo.;�i, !IS i-"ESPONSIBLE FORI, PROWDED BY 7HE OWNER. MIS LOT T x NOT BEEN SURVEYED EROSION CON, RUL AND DRAINAGE CO. (TYP) Cli 0 z 12' x 6' x 5.4(D), CONCRETE DDENRON TAUK _6 A __95 DS (TYP) V_ UJI 62' 0 0 65 LEVEL SfiRbDER W--'5- JNF7LM77ON-4" PERF PVC 25'-4 P PERF PVC 1J'-4" PVC @1Z PROPOSED HOUSE FINISH FLOOR = 97.5 0 2417 SQ.FT (1ST FLR.) 24' -0 591 SQ. FT. (2ND FLR.) 96— ACO TROUG DRAIN (25' -OR-EQUAL RIM = 96 SI IE= 96.4+/- C RIGHT - EX. WATER METER �:_ �_o I 2 a� GARAGE �IlqISH FLOOR = 97.41 755 SQ. Fr. 4 U) U) J r Co��'ng,'7� Z, PERMIT 74 "IF-AA)RIED Cq D -CONCRETE DRIVE V) w ...... B 00 F2000-GAL DETEN77ON TANK 2000-GA np f)r C OP OF SLAB 97 T T OE= 95.80 1E (IN) = 95 0 1E (OUT) =92.4 VL I ORIF EL= 91.9 DIA= 1!li6" . BOT = 90.90 GRAPHIC SCALE 0 10 20 40 IN FEET 1 inch 20 ft. CONTOUR INTERVAL = 1 FOOT CONTOURS ARE ESTIMA7ED BASED UPON FIELD ELEVAT16NS PROWDED BY THE OWNER. THIS SITE HAS NOT BEEN SURVEYED. ELEVATIONS ARE APPROXIMA TE ONLY. OVERFLOW V ELEV. = 95.8—.* 4- RISER W/ PIPE SUPPORT 4* PVC OUTLET PIPE T IN VER T ORIFICE EL E V. = 9 2. 43 11116- 11AIMETER ELEV=91.9 +/- 60 1 ACCEPTABLE TIGHTLINE MATERIA1_ SDR 35 SCH 40 N-12 D 35 F810 HANCOR Applicant shall repair/replaoe all damage to utilities or frontage imprvImments In City right-of-way per City standards that IB caused C or oocurs during the permMed projed. EX. PICKET FNC 9 5 Access Hole to Accept 24'Dia Hatch. IE(IN) = 95.0' Knockout for 4"PVC PLAN VIEW in CLEANOUT GATE 'SZ — — — — .. Z, + - 'ELEV. �--25.5'. " PVC FABRICATE LOW RESTRICTOR )P OF LID= 970 OT OF LID= 96.3 E =95.8 =92.4 (OUT) .- 95. 0 (IN) OTTOM= 90.9 C,4 FLOW RESTRICTOR SECTION VIEW NOT TO SCALE nvrpvi rprnAT TIATTTrP cl-� r� YOIRES 101113f T57- 571 74 he- 4e�x_r e- 00?,eXr4w CUZ Utility Vault CCP612(or equal) 2,000 Gallon (69" x 57"x 65"D) APPROVED)-k§ NOTED RING SIbEET FILE Date://"" 11� v11 I I SBEET TME: SFR DRAINAGE PLAN BLD 20090041 CLEENT: Tom Matuszewski 21429 - 84th Avenue W Edmonds,, WA. I OF 2 gzexot 4; &_ %.re-eze-�4— f *ot ee.0, 4 2-5. 2 ?/. cjzX57 _J, Msh mabi Ord cap a rpIL9 V I C. Olean co-rtwp-- fpDm pip-m 0 ID a r raud p IL--Vk p ftDtO fMd cha g;;dQ t�m= A 2*x 21 ftmtoa 7 9 type I C- 0 wAmId Doxe r (kx ldngi 1& 0.0. FEI LO A miluantpipa (ffrx=:agrk ibv s az 0 FS per tmnr.h) A q,-- *jgan o,-rtwy2 -r-Dm p02 PLAN mm P00'a gaVemed brjLss L-D 1'40[ 1--; P-ITZP —'ALOV, Vxi:"� I - . a pre;wure d.7 0 f%4 4P'orEP perhrated Ward i3 9 .9 pipe laid iw . 1 .1 F a j -4' x 4'm dew �559v" f mem) IW- `W "w-whed mok -CP fker*P.briG ' — lato— flov m*W%veter fpalty SECTIONA-A urs lew m smoorid disper3al 'remb if neczeruairr B ;own r fbwiao*cr br.wvlh hS C; EP:g T L board noftte3 N 0 TE Gt 1. This lierch shall te ccrmmecl so az t; pmmnt paim diva twigm- wAh r a FD6Dn. 2. Trenr:l-e3: rra:y be p1med no c b3er ihaa 60 f5ml -b one amalhe r. (100 15ei ,ab rq tbwl ra) 3. Trenr-h mid!3 mcle bcL!Lrd must be krkem L A fgn iD fDl Lw cor*oumofmilm. 4.,%p pc>rt poatzpaoing ac mq drad by :coil candtims to erizu P!g mda ba= rerrtmin3 level. C - EXPIRES 101131 IA* I / Z4 /Z" F. 0 .1 rj Wei a 413 r. 4 V 16 I ve, New tb "MOM X4ft'-- . MIN ;w Irp i d" I W lltwwft� rd—w- kiffa. mc!CN "&bout pa I Cf pw 7w-sq- a- J. C*.Mc DONNELL & ASSOCIAES CONSULTING CIVIL ENGINEERS P.O. Box 13199 Mill Creek, WA. 98082 STORM DRAINAGE STUDY For MATUSZEWSKI SFR Located at 21429-84 T' AVENUE WEST Edmonds, WA. 98020 DEVELOPER: Mr. Tom Matuszewski P.O. Box 95 PMB 553 Stanwood, WA. 98292 LEGAL DESCRIPTION AMMWOMI NtkkO.:tCgBIKOD3D-02-LOT7-=3=E4MFr&=N?5'FT&EMS-i5ET PREPARED BY: J. C. McDonnell, PE Surveyor of Record: NONE Issue Date: March 13, 2009 Revision Date: /7),jr& �* 2 rEXPIRES 10M 3 / 2- & SIVA 1 r1it A OVED AS NOTED ENGINEERING ��at EXISTING CONDITIONS 21429-84 TH AVENUE WEST Edmonds, WA. 98020 The proposed project is th an undeveloped lot located on the east side of 84 1h Avenue W. mid block between 214 Place SW and 215th Street SW in Edmonds, WA. 98020. The Legal Description places the property in NE 1/4Section 30, Township 27N, and Range 04 WM. The lot was previously the original farmhouse of the area and was recently destroyed by fire. The proposed building will replace the original house. The old house and supporting surfaces have been removed. Sewer, water, telephone and power utilities are available in the street. However, because the site requires detention and sits below the elevation of the public storm drain, it is necessary to consider using infiltration or level spreading to dispose of the rooftop runoff. Detention will be used to reduce the length of level spreader/infiltration trench required in order to take advantage of the limited field size of suitable soils. Detention for this Single Family residence will be conventional underground concrete utility vault modified to support a 50-SF level spreader/infiltration field to be constructed in 36 to 42 inches of Alderwood series GSL. The alternative appears to be to pump stormwater after detention to the Public Storm Drain in 84d. The goal is to eliminate the use of pumping with the need for external power and to meter the rooftop stormwater after detention into the soil. The Snohomish County Soil Survey lists the site soil type as Alderwood Gravely Sandy Loam with 2 to 8 percent slopes. The Gravely Sandy Loam corresponds to a type "C" soil with CN's of 81 to 85 depending upon the vegetation and cover conditions. A soil log was prepared within the proposed infiltration area revealing an Alderwood soil depth of 36" to 42" GSL underlain by the conventional hard layer, a combined gray sandy clay layer with seepage across the till layer. The Snohomish Soil Survey provides an average permeability range of 2.0 to 6.0 in/hr. J.C.McDonnell Engineering, PS 2 0 0 DEVELOPED SITE CONDITIONS The proposed project will construct approximately 4,400 SF of new rooftop and driveway surfaces to 0.455 acres of land. The development requires detention but not water quality treatment since the paved surfaces will be a 25-foot x 30-foot driveway and a covered garage. Total exposed driveway surface will be 750 SF. Driveway runoff will be collected into a small trough drain and diverted into the roof drain system. It the site could reach the public conveyance by gravity, the detention could be sized from Tables provided by the City of Edmonds providing standard storage volumes based upon the square footage of impervious to be constructed. However, since such access is currently not available, an onsite system is proposed. By the pertinent Edmonds regulation for a house of this size (4.400 SF new impervious) detention from a standard table would be required with an internal restrictor and gravity pipe conveyance to the public storm drain in 84th Avenue W. According to City publications, this site would normally require the pipe equivalent of 40 LF of 30" pipe (196 CF or 1,466 GAL) and a 7/8" orifice to discharge to the public storm drain. However, since gravity to the storm drain cannot be achieved due to the low site elevation, we can either: I . Pump the stormwater to the street. 2. Provide a drywell of sufficient size to handle all the runoff from the rooftop of the new structure or 3. We can detain the runoff and meter it into a smaller drainfield at a restricted flow rate or a level spreader as allowed by DOE, 2005. In this case, the availability of some soil in excess of 36" in depth is limited, so flow will be restricted to a level spreader/infiltration field of 100 — 150 SF (i.e. 50 - 75LF of level spreader/ 2-foot trench). The trench section will be conventional 2' x 2' trench with a 4" perforated PVC pipe buried in drain rock or equal. The detention size is increased to allow a reduction in the release rates within this drywell structure. The trench will be open to the surface to allow storm overflows to be released to the downstream as a sheet flow as permitted by the City of Edmonds. The surrounding conditions suggest that this can occur without damage to neighboring properties. Soil Logs: SL-1 0 — 8" Topsoil 8 "- 4 1 " Alderwood GS L 41 " Plus Hardpan SL-2 0 — 36" Alderwood GSL 36"+ Hardpan SL-3 0- 29" Alderwood GSL 29"+ Hardpan SL-4 0- 27" Alderwood GSL 27"+ Hardpan J.C.McDonnell Engineering, PS 3 SITE HYDRAULIC ANALYSIS The detention for the site will be conventional concrete tank, a 2,000 Gal utility vault, modified to serve as a detention structure with a restrictor, an overflow 4" stand pipe and an outlet orifice per Edmonds standards. The restrictor will be small diameter pipe and can be fabricated from 4" PVC pipe and fittings. Total Property Area 0.455 Acres, Development Area 0.455 Acres Existing Pervious 0.455 Acres Existing Impervious Area 0.000 Acres New House Footprint 2,417 SF New Garage 755 SF New Walks, Drive & Stuff 1,239 SF New Surface Area 4,411 SF 0.101AC Proposed Impervious 0. 10 1 Acres Proposed Pervious = 0.359 Acres A. DESIGN CRITERIA The City of Edmonds Drainage Ordinance requires that storm water from new impervious surfaces created by development must be detained. The Drainage System Standard Plans further provides that if impervious development is less that the 5,000 sf threshold, a standard pre -tabulated City Drainage table can be used to develop the required storage volume. This site is eligible for the Standard Plans. Since the site cannot drain to the public conveyance by gravity, 100-year 24-hour detention is provided with a release to a level spreader in the rear yard area. The 2005 DOE Stormwater Manual Page 3-12 provides design criteria for a dispersion trench downstream from the detention vault which will dissipate the stormwater to a sheet flow. The published design criteria are provided on a following page. B. DETENTION VOLUME With Impervious area= 4,411 SF Detention Req'd Per Edmonds Table 1= 112 CF =838.76Gal. "2,000" Gal Detention Tank (Modified Utility Vault CCP 612 per CUZ Conc.) Inside L = 12' Inside W = 6 6 Depth = 5.4' Gal/ft 538.6 Volume 388 CF = 2,908 Gal 'available Air Space 0. 5' = 134 Gal Detention Volume= 3.9'=2,10OGal Dead Storage = 1.0' = 538.6 Gal Restrictor size = 7/8" per City of Edmonds Restrictor size per SBUH Engineered Design = 11/16". J.C.McDonnell Engineering, PS 4 0 0 SITE HYDRAULIC ANALYSIS Design Criteria for Dispersion Trenches A vegetated flowpath of at least 25 feet in length must be maintained between the outlet of the trench and any property line, structure, stream, wetland, or impervious stu-face. A vegetated flowpath of at least 50 feet in length must be maintained between the outlet of tile trench and any steep slope. Sensitive area buffers may count towards flowpath lengths. 2. Trenches serving up to 700 square feet of roof area may be simple 1 0-foot-long by 2-foot wide gravel filled trenches as slio-%Aqi in Figure 3.5. For roof areas larger than 700 square feet, a dispersion trench with notched grade board as shown in Figure 3.6 may be used as approved by the local jurisdiction. The total length of this design must not exceed 50 feet and must provide at least 10 feet of trench per 700 square feet of roof area. 3. A setback of at least 5 feet should be maintained between any edge of the trench and any structure or property line. 4. No erosion or flooding of downstream properties may result. 5. Runoff discharged towards landslide hazard areas must be evaluated by a geotechnical engineer or a licensed geologist, hydrogeologist, or engineering geologist. The discharge point may not be placed on. or above slopes greater than 20% or above erosion hazard areas without evaluation by a geotechnical engineer or qualified geologist andjurisdiction approval. J.C.McDonnell Engineering, PS 0 0 SITE HYDRAULIC ANALYSIS (cont.) Level Spreader Detail 3.5 per DOE TME HWMN- CAP - Wo ]Cfpw?W Wt A ^4 MN VEW W AMF Flnure &5 T*ckaf 0ownwood UkDomim TA-nca Sw-ft, Xlqcd-my J.C.McDonnell Engineering, PS SITE HYDRAULIC ANALYSIS (cont.) Level Spreader Detail 3.6 per DOE ard cap at plu3 Immswarid dispet-Aiterch V . . 010"ricutw1oflom pip.-- if 6 WorWparl:mUd p" Uku ftVIM121 r. oto hLd a mdo t-=rd ViTrimirr" 9 trp: 10 9 %Vzold we r (Ioc �ngj Type I CR A +%-V:sdid coe r 04 imllmmt,lp V..qn 4kiw-1,0S0F5VertrenrN d 't i5-0124A outwpfpDm Poo PLAN urs ")eMed boVs V-D 11.0 "Ado-, VOL a Ir Pm=ure trmz=9=Q 4� or F? perkto-ed toard .9 pipe Im ikm A1x 4=pport post 4W—Tt"w�hrd rk met 6bk 1:m fffix (Ly flou mmmuter qiajl.y tedmt in n4w amm, SECTIONA-A Ws fLw io A-c r br."h N r. E?G as nxamaq le 0.0. 2" T N 0 Tr- st I. T%merch shW1 be omsmedsD a3b preient Poirt il�xhmu-- erdbr 0 IDZIDD. 2. TrermFes m!W be p1wed no c b---r ftm 60 *Del t) One aixilbe: r. (IDO fWl ab rq fbwl nm) 3. Tmnrh Mid 9 mde bmid mir-A be bNe L A bn ID ful bw comDumofzie. 4. aip port p= zpaoing = raq drad by =11 cordkitmc to aru 10 9 rada bozm fernahs Figure 3.6 Standard INspersion Trench with Notched Grade Board J.C.McDonnell Engineering, PS 7 40. SITE HYDRAULIC ANALYSIS QrMell Sizing Calculation Rooftop Area = 3,172 SF divides by 700 SF = 4.53 Pavement Area = 1,239 SF/700 = 1.77 Length of Level Spreader = 6.30 x 10 LF = 63.0 LF minimum Let the Level Spreader/ Drywell be a minimum of 65.0 feet in length. Since all rooftop area runoff will be directed through one outlet from the detention, it is reasonable to keep the spreader as a single trench with a single run of pipe. DOWNSTREAM CONDITIONS Site detention will discharge by a 4" pipe conveyance to a drywell in the rear yard area as described above. There is no piped outlet available on the downstream property. Currently the rear yard drops in elevation to a low point at or slightly east of the property line. The grade begins to rise in the neighbor's yard to the east. The overall terrain slopes North & east. Since the rear yards are lower than the respective houses, it seems reasonable to suppose that any surface flows that may occur during highly intense storm events might pond in the yard areas without harming any structures. The proposed design under foreseeable conditions including an isolated 100-year peak event will be dissipated into the soil without a noticeable impact on downstream properties. The project is small relative to the lot size in question and the neighborhood is currently designed to a density of 1 unit per 0.4 acres. Therefore, we do not expect the stormwater to appear on the surface in foreseeable conditions as long as reasonable care & maintenance is taken to prevent'the drywells from silting up or plugging. The soils were examined on a winter day in early March 2009 when winter high water table conditions would reasonably be expected to apply. The soils were observed to be well draining down to the hard pan layers as indicated. J.C.McDonnell Engineering, PS 8 ENGINEERING REPORT APPENDICES J.C.McDonnell Engineering, PS 0 0 1. Site Vicinity Map J.C.McDonnell Engineering, PS 10 0 0 VICINITY MAP 0 U h 4�N i�w ."102th-PI S1 Mwn St iAi UfPh 2 Sk pt sw 112th St� '61 Z 21 Pi i'f L /< 215,tUhl St U a —,7� F e7i k �_J�p "N' 2215L P1 k. Q!2009wpowginc.-� 04 _P�i" 7009 HAV_ Jr,6. M600NNO-1- 6N61N&591N6 P6 4onsulfing 4ivil Cngineers W06- zap` 5\q, $to _30(p Mountlaice Torraco, WK W43 (42.5) 144-oqi5 (Tot) (42-5) -144-oq4(p (FAY,) e -mail: jocdonz@vorizon.not Tom Matuszeuski 21429 — 84th Avenue W Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: I Photobase I 2. Aerial Topography Map J.C.McDonnell Engineering, PS I I USGS BASIN TOPOGRAPHY M .7 N. V . 6 J; A V _777 A. Wilt- TL P075 i*.j name P M,- .4* .�3 61 Jr 4 _.*w LM Tom Matuszeuski J'6. MCPQNNC1_L CNWNCC,9� 21429 — 84"' Avenue W 6onsulfing,Civil Cagineers Edmonds, WA (0(006- 21(pl, cow, 5to -30(p tftuntlalco Torraco, WA. W413 (4?-5) 144 - oqi5 (Tol) (4?-5) -144 - oq4(p (FAY.) SCALE: None DATE: SHEET: 6 -mail: jt0rdon?_@v0rizon.net JOB NUMBER: FILE NAME: BY: Photobase 2 9 1 0 BUILDING SITE 47 'A— _4L"k 4do Ic X16. M-1PONNeu cN61Nccp1tN6 Pic 40"Sulfing 4ivil Cngineers wpos- %1(01 sw, Cato -30(p Mountlalce Torrace, WK qSo43 (4z5) 144-oq15 (Tol) (42-5) 144-oq4(o (FAY.) e -mail: j4%cdon-z@verizon.net Tom Matuszeuski 21429 — 84th Avenue W Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: I Photobase 3 -7 MF uga 13 0 0 DOWNSTREAM OF DRYWELL SITE 2 Jr1c. WPONN61-1- 6N611V60Z1N6 P4 4onsulfing civif Cn9ineers (Apos- 21V" 15w, Ste 30(p tAountlaVe Terrace, w1k. qSO43 (4?-5)144-oql5 (Tol) (4z5) -144-oq4(p (FA)() 6 -mail: jocdon"verizon.net 4* . At- Tom Matuszeuski 21429 — 84h Avenue W Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: I Photobas.e 5 0 0 I Edmonds Drainage Calculations & Exhibit a. Detention Sizing Calculations J.C.McDonnell Engineering, PS 12 3/16/09 2:59:43 pm J.C. McDonnell & Associates page I MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B002 NAME: 2 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 1.50 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr:l 1.50 s:0.0500 PEAK RATE: 0.01 cfs VOL: 0.00 Ac-ft TIME: 490 min BASIN ID: B010 NAME: 10 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.20 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.02 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: B025 NAME: 25 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.80 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min J.C.McDonnell Engineering, PS 13 0 E 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 2 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B100 NAME: 100 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 3.30 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:O..1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D002 NAME: 2 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAiNFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 1.50 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: D010 NAME: 10 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.20 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.04 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D025 NAME: 25 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.80 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.06 cfs VOL: 0.02 Ac-ft TIME: 480 min J.C.McDonnelI Engineering, PS 14 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 3 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: D100 NAME: 100 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 3.30 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.07 cfs VOL: 0.03 Ac-ft TIME: 480 min J.C.McDonnell Engineering, PS 15 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 4 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF CONTRIB NUM RATE PEAK HYDRO AREA CFS MIN. CF\ACFT ACRES UNDEVELOPED 1 0.006 490 166 CF 0.10 2-YEAR 2 0.016 480 346 CF 0.10 10-YEAR 3 0.026 480 521 CF 0.10 25-YEAR 4 0.034 480 676 CF 0.10 100-YEAR DEVELOPED 5 0.030 480 469 CF 0.10 2-YEAR 6 0.045 480 723 CF 0.10 10-YEAR 7 0.058 480 942 CF 0.10 25-YEAR 8 0.069 480 1125 CF 0.10 100-YEAR DETENTION VAULT PERFORMANCE 9 0.012 540 397 CF 0.10 2-YEAR 10 0.017 ' 550 651 CF 0.10 10-YEAR 11 0.020 560 870 CF 0.10 25-YEAR 12 0.023 560 1053 CF 0.10 100-YEAR J.C.McDonnell Engineering, PS 16 0 9 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 5 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE STORAGE TABLE RECTANGULAR VAULT ID No. 200OG Description: Length: 12.00 ft. Width: 6.00 ft. voids: 1.000 STAGE --STORAGE STAGE -STORAGE- STAGE --STORAGE ---- > STAGE -STORAGE-- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- 91.40 0.0000 0.0000 92.70 93.600 0.0021 94.00 187.20 0.0043 95.30 280.80 0.0064 91.50 7.2000 0.0002 92.80 100.80 0.0023 94.10 194.40 0.0045 95.40 288.00 0.0066 91.60 14.400 0.0003 92.90 108.00 0.0025 94.20 201.60 0.0046 95.50 295.20 0.0068 91.70 21.600 0.0005 93.00 115.20 0.0026 94.30 208.80 0.0048 95.60 302.40 0.0069 91.80 28.800 0.0007 93.10 122.40 0.0028 94.40 216.00 0.0050 95.70 309.60 0.0071 91.90 36.000 0.0008 93.20 129.60 0.0030 94.50 223.20 0.0051 95.80 316.80 0.0073 92.00 43.200 0.0010 93.30 136.80 0.0031 94.60 230.40 0.0053 95.90 324.00 0.0074 92.10 50.400 0.0012 93.40 144.00 0.0033 94.70 237.60 0.0055 96.00 331.20 0.0076 92.20 57.600 0.0013 93.50 151.20 0.0035 94.80 244.80 0.0056 96.10 338.40 0.0078 92.30 64.800 0.0015 93.60 158.40 0.0036 94.90 252.00 0.0058 96.20 345.60 0.0079 92.40 72.000 0.0017 93.70 165.60 0.0038 95.00 259.20 0.0060 96.30 352.80 0.0081 92.50 79.200 0.0018 93.80 172.80 0.0040 95.10 266.40 0.0061 96.30 352.80 0.0081 92.60 86.400 0.0020 93.90 180.00 0.0041 95.20 273.60 0.0063 J.C.McDonnell Engineering, PS 17 0 0 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 6 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. 200OGx Description: Design 25 yr Outlet Elev: 92.40 Elev: 91.90 ft Orifice Diameter: 0.6880 in. STAGE <DISCHARGE> STAGE <DISCHARGE> STAGE -DISCHARGE- STAGE DISCHARGE> (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- 92.40 0.0000 93.40 0.0128 94.40 0.0182 95.40 0.0222 92.50 0.0041 93.50 0.0135 94.50 0.0186 95.50 0.0226 92.60 0.0057 93.60 0.0141 94.60 0.0191 95.60 0.0230 92.70 0.0070 93.70 0.0146 94.70 0.0195 95.70 0.0233 92.80 0.0081 93.80 0.0152 94.80 0.0199 95.80 0.0237 92.90 0.0091 93.90 0.0157 94.90 0.0203 95.90 0.0240 93.00 0.0099 94.00 0.0162 95.00 0.0207 96.00 0.0244 93.10 0.0107 94.10 0.0167 95.10 0.0211 96.10 0.0247 93.20 0.0115 94.20 0.0172 95.20 0.0215 96.20 0.0250 93.30 0.0122 94.30 0.0177 95.30 0.0219 96.30 0.0254 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 7 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE RISER DISCHARGE ID No. Risl Description: Riser Diameter (in): 4.00 elev: 95.80 ft Weir Coefficient ... 9.739 height: 96.30 ft Orif Coefficient ... 3.782 increm: 0.10 ft STAGE <-DISCHARGE- STAGE <-DISCHARGE--> STAGE <-DISCHARGE-> STAGE <DISCHARGE --- > (ft) --- cfs -- ------- (ft) --- cfs -- ------- (ft) --- cfs -- ------- (ft) --- cfs -- ------- 95.80 0.0000 95.90 0.1329 96.10 0.2302 96.30 0.2971 95.80 0.0000 96.00 0.1879 96.20 0.2658 96.30 0.2971 J.C.McDonnell Engineering, PS 18 E 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 8 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. combol Description: Structure: 200OGx Structure: Structure: Risl Structure: Structure: STAGE <--DISCHARGE- STAGE -DISCHARGE STAGE -DISCHARGE STAGE -DISCHARGE (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- 92.40 0.0000 93.70 0.0146 95.00 0.0207 96.30 0.3225 92.50 0.0041 93.80 0.0152 95.10 0.0211 96.40 0.3512 92.60 0.0057 93.90 0.0157 95.20 0.0215 96.50 0.3776 92.70 0.0070 94.00 0.0162 95.30 0.0219 96.60 0.4022 92.80 0.0081 94.10 0.0167 95.40 0.0222 96.70 0.4�53 92.90 0.0091 94.20 0.0172 95.50 0.0226 96.80 0.4472 93.00 0.0099 94.30 0.0177 95.60 0.0230 96.90 0.4680 93.10 0.0107 94.40 0.0182 95.70 0.0233 97.00 0.4879 93.20 0.0115 94.50 0.0186 95.80 0.0237 97.10 0.5070 93.30 0.0122 94.60 0.0191 95.90 0.1569 97.13 0.5126 93.40 0.0128 94.70 0.0195 96.00 0.2123 93.50 0.0135 94.80 0.0199 96.10 0.2549 93.60 0.0141 94.90 0.0203 96.20 0.2908 J.C.McDonnell Engineering, PS 19 0 3/16/09 2:59:45 PM J.C. MCDONNELL & ASSOCIATES PAGE 9 MATUSZEWSKI SINGLE FAMILY EDMONDS ROOFTOP 200OG DETENTION MARCH 16,2009 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE < -------- DESCRIPTION --------- > (CFS) (CFS) --ID- --ID- <-STAGE> ID (CFS) VOL (CF) 2-YEAR ...................... 0.01 0.032000GCOMBOI 93.28 9 0.01 135.66CF 10-YEAR ...................... 0.02 0.04 200OG CONMOI 94.10 10 0.02 194.58 CF 25-YEAR ...................... 0.03 0.062000GCOMBOI 94.8911 0.02 251.01CF 100-YEAR ..................... 0.03 0.072000GCOMBOI 95.5812 0.02 301.09CF J.C.McDonnell Engineering, PS 20 4. Available Soil Data J.C.McDonnell Engineering, PS 21 0 rj VI 0 K M --I M �U ch M W C, C C c �� Mn - M M CO M X Ul 0) 0 This soll I survey map was compiled by the U S.DeDertment a I Agriculture. Sol I Cons owe tion Semi ce, and cooperating agencies. . Base MDP. are wthapholographa prepared bythe State of Washington. Department of Natural Resources from 1973 and.1974 serial photography. Coordinate and ticks and land division cornets, It shown. are DDPfDXIMO[elY positituied. 183 Snohomish County Area, Washington TABLE 14.--PHYSICAL AND CHEMICAL -PROPERTIES OF SOILS [The symbol < means less than; > means more than. Entries under "Erosion factors--T" apply to the entire apply only to the surface laYer. Absence of an entry indicates profile. Entries under "Organic mattei that data were not available or were not estimated] Soil name and jDepthjClay <2mmj Permeability map symbol i In ct n/hr 1 0-7 1 1, 2, 3 ---------- I 5-10 1 2.o-6.o Alderwood 1 7-351 5-10 1 2.0-6.0 1 35 1 --- 4*: Alderwood ------- 1 0-7 1 5-10 2.0-6.o 1 7-351 5-10 2.0-6.0 1 35 1 --- Everett --------- 1 0-6 1 5-10 2.0-6.0 1 6-181 5-10 6.0-20 118-601 o-5 6.0-20 5*, 6*: Alderwood ------- 1 0-7 1 5-10 i 2.0-6.0 1 7-351 5-10 1 2.0-6.0 1 35 1 --- Urban land. 7 -----------------1 0-9 1 15-30 1 0.2-0.6 Bellingham 9-601. 40-60 1 0.06-0.2 8 ---------------- 1 0-6 27-35 1 0.2-0.6 Bellingham 1 6-421 35-45 12-30 1 1 0.06-0.2 0.2-0.6 Variant 142-601 9, 10, 11 -------- 0-8 0 6-2.0 Cathcart 1 8-351 0:6-2.0 135-601 0.6-2.0 12*. Cryohemists 13 --------------- 1 0-9 1 1 9 -351 10-15 0 -10 1 1 2.0-6.0 0.2-0.6 Custer 135-601 0-10 i >20 14 --------------- 1 0-2 1 0.6-2.0 Elwell 1 2-231 0.6-2.0 123-27: 0.6-2.0 1 27 15*: Elwell ---------- 1 0-2 0.6-2.0 1 2-231 0.6-2.0 1123-27, 1 0.6-2.0 1 27 Olomount -------- 1 0-2 o.6-2.0 1 2-181 o.6-2.0 1118-321 --- 0.6-2..0 32 16*: ElwVll ---------0-2 --- 0.6-2.0 1 2-.231 o.6-2.0 123-271 0.6-2.0 27 See footnote at end of table. i I Available 1 Soil I Shrink -swell water capacity !reaction! potential Erosion i factors jOrganic matter K It T I — 2 0.07-0-11 15.1-6.5 !Low ------------ 10.201 0.07-0.11 1-5.6-6.5 !Low ------------ 10.201, --------------- : ---- ! Is 11 It It 11 10.201 2 0.07-0-11 15.1-6.5 Mow ------------ 0.07-0-11 15.6-6.5 tLow ------------ 10.201 --------------- 1 0.08-0.12 15.6-6.5 Mow ------------ 10-171 1 0.05-0.08 15.6-6.5 Mow ------------ 10.10', 0.02-0.05 15.6-6.5 !Low ------------ 10.10, I It 10.201 2 0.07-0-11 15.1-6.5 !Low ------------ 0.07-0-11 15.6-6.5 !Low ------------ 10.201 --------------- 1 0.20-0.24 15.6-6.5 !Low ------------ 10-321, 5 0.20-0.24 16.1-7.3 !High ----------- 10.24-, 0.19-0.21 15.1-5.5 IModerate ------- 10-321 5 14.5-5.5 !High ----------- 10-321 0.14-0.16 14.5-5.0 !Moderate ------- 10-321 S It 1 1 0.18-0.20 114.5-6.0 !Low ------------ 10-371 5 0.13-0-17 15.1-6.5 !Low ------------ 10.431 0.14-0.17 15.1-6.5 !Low ------------ 10-371 0.13-0-15 15.6-6.0 !Low ------------ 10.281 5 0.06-0.08 15.1-5.5 !Low ------------ 10.241 0.06-0.09 15.6-6.0 Mow ------------ 110.101, 2 0.22-0.26 13.6-5.5 !Low ------------ 10.371 0.19-0.23 15.1-5.5 !Low ------------ 10:431 0.09-0.13 115.1-5-5 -',Low ------------- 10.2811 i--------------- 0.22-0.26 13.6-5.5 !Low ------------ 10-371 2 0.19-0.23 15.1-5.5 !Low ------------ 10.431 0.09-0.13 15.1-5.5 !Low ------------ 10.2811 --------------- 0.13-0-16 15.1-5.5 !Low ------------- 10.241 2 0.11-0.14 15.6-6.0 !Low ----------- �10.281 0.08-0-10 15.6-6.5 !Low ------------ 10.281 0.22-0.26 13.6-5.5 !Low ------------ 10-37, 2 �0.19-0.23 15.1-5.5 !Low ------------ 10.431 0.09-0.13 15.1-5.5 Mow ------------ 10.281 --------------- J. CO.MC D ONNEL L & ASS 0 CIAES CONSULTING CIVIL ENGINEERS P.O. Box 13199 Mill Creek, WA. 98082 STORM DRAINAGE STUDY For MATUSZEWSKI SFR Located at 21429-84 T" AVENUE WEST Edmonds, WA. 98020 DEVELOPER: Mr. Tom Matuszewski P.O. Box 95 PMB 553 Stanwood, WA. 98292 LEGAL DESCRIPTION AWMWOM M42NOR C9 3EK OS r,02 - LOT 7 ME E 430 FT & OX N 75 Fr & EM S 75 �Tl Issue Date: March 13, 2009 Revision Date: PREPARED BY: J. C. McDonnell, PE Surveyor of Record: NONE SIRE15 f IVE Ze". MAR 19 2009 SU""'(' 'EA41R?TWN-r CITY OF E0'W0jVQ EXISTING CONDITIONS 21429-84 T' AVENUE WEST Edmonds, WA. 98020 The proposed project is an undeveloped lot located on the east side of 84 th Avenue W. mid block between 214th Place SW and 215'h Street SW in Edmonds, WA. 98020. The Legal Description places the property in NE 1/4 Section 30, Township 27N, Range 04 WM. The lot was previously the original farmhouse of the area and was recently destroyed by fire. The proposed building will replace the original house. The old house and supporting surfaces have been removed. Sewer, water, telephone and power utilities are available in the street. However, because the site requires detention and sits below the elevation of the public storm drain, it is necessary to consider using infiltration to dispose of the rooftop runoff. Detention will be used to reduce the length of infiltration trench required in order to take advantage of the limited field size of suitable soils. Detention for this Single Family residence will be conventional underground concrete utility vault modified to support a 200-SF infiltration field to be constructed in 36 to 42 inches of A.1derwood series GSL. The alternative appears to be to pump th stormwater after detention to the Public Storm Drain in 84 . The hope is to eliminate the use of pumping with the need for external power and to meter the rooftop stormwater after detention into the soil. The Snohomish County Soil Survey lists the site soil type as Alderwood Gravely Sandy Loam with 2 to 8 percent slopes. The Gravely Sandy Loam corresponds to a type "C" soil with CN's of 81 to 85 depending upon the vegetation and cover conditions. A soil log was prepared within the proposed infiltration area revealing an Alderwood soil depth of 36" to 42" GSL underlain by the conventional hard layer, a combined gray sandy clay layer with seepage across the till layer. The Snohomish Soil Survey provides an average permeability range of 2.0 to 6.0 in/hr. Given the small size of the proposed construction, the cost of geotechnical evaluating this soil with falling head percolation is considered unwarranted. It is reasonable to assume for the purposes of this design that the average percolation rate of this site's soil is at least 4.0 in/hour. We will apply a Safety Factor of 2 to the minimum average permeability, which will allow us to develop a reasonable drywell size with a conservative percolation rate of 2.0 in/hour (i.e. 30 min/in). Since the Alderwood series GSL is 36-42 inches deep in the proposed drywell area, the proposed drywell will be set 12-inches or more above the hardpan layer with a design depth of 24-inches. Additional fill of topsoil depths of 12- inches or so may be used over the top landscaping and site grading. J.C.McDonnell Engineering, PS 2 0 DEVELOPED SITE CONDITIONS The proposed project will construct approximately 4,400 SF of new rooftop and driveway surfaces to 0.455 acres of land. The development requires detention but not water quality treatment since the paved surfaces will be a 25-foot x 30-foot driveway and a covered garage. Total exposed driveway surface will be 750 SF. Driveway runoff will be collected into a small trough drain and diverted into the roof drain system. It the site could reach the public conveyance by gravity, the detention could be sized from Tables provided by the City of Edmonds providing standard storage volumes based upon the square footage of impervious to be constructed. However, since such access is currently not available, an onsite system is proposed. By the pertinent Edmonds regulation for a house of this size (4.400 SF new impervious) detention from a standard table would be required with an internal restrictor and gravity pipe conveyance to the public storm drain in 84th Avenue W. According to City publications, this site would normally require the pipe equivalent of 40 LF of 30" pipe (196 CF or 1,466 GAL) and a 7/8" orifice to discharge to the public storm drain. However, since gravity to the storm drain cannot be achieved due to the low site elevation, we can either: 1. Pump the stormwater to the street. 2. Provide a drywell of sufficient size to handle all the runoff from the rooftop of the new structure or 3. We can detain the runoff and meter it into a smaller drainfield at a restricted flow rate. In this case, the availability of some soil in excess of 36" in depth is limited; so now will be restricted to an infiltration field of 200 SF (i.e. 100 LF of 2-foot trench). The trench section will be conventional 2' x 2' trench with a 4" perforated PVC pipe buried * in drain rock or equal. The detention size is increased to allow a reduction in the release rates within this drywell structure. According to the hydraulic analysis, the infiltration bed will absorb the 25-year storm volume at a depth of 1.5-foot. The 100-year event will be absorbed at 1.81 foot depth in a 2' trench. Any excess flows will exit the system at the yard drain gate and sheet flow into the rear yard area. The surrounding conditions suggest that this can occur without damage to surrounding properties. Soil Logs: SL-1 0 — 8" Topsoil 8"- 41" Alderwood GSL 41 " Plus Hardpan SL-2 0 — 36" Alderwood GSL 36"+ Hardpan SL-3 0- 29" Alderwood GSL 29"+ Hardpan SL 4 0- 27" Alderwood GSL 27"+ Hardpan J.C.McDonnell Engineering, PS 3 SITE HYDRAULIC ANALYSIS The detention for the site will be conventional concrete tank, a 2,000 Gal utility vault, modified to serve as a detention structure with a restrictor, an overflow 4" stand pipe and an outlet orifice per Edmonds standards. The restrictor will be small diameter pipe and can be fabricated from 4" PVC pipe and fittings. Total Property Area 0.455 Acres, Development Area 0.455 Acres Existing Pervious 0.455 Acres Existing Impervious Area 0.000 Acres New House Footprint 2,417 SF New Garage 755 SF New Walks, Drive & Stuff 1,239 SF New Surface Area 4,411 SF 0.101AC Proposed Impervious 0. 10 1 Acres Proposed Pervious = 0.359 Acres A. DESIGN CRITERIA The City of Edmonds, Drainage Ordinance requires that storm water from new impervious surfaces created by development must be detained. The Drainage System Standard Plans further provides that if impervious development is less that the 5,000 sf threshold, a standard pre -tabulated City Drainage table can be used to develop the required storage volume. This site is eligible for the Standard Plans. Specifically, the ordinance requires that "a retention control device must be provided in order to maintain surface water discharge rates at or below the 25-year, 6-hour rainfall event." It is further requires that the "retention/detention facility must be constructed to store the runoff from a 100-year, 12- hour rainfall event." The code allows the City Engineer to accept different but equivalent standards. The King Count Small Project Drainage Requirement (Appendix C) has been suggested as a possible reference. B. DETENTION VOLUME With Impervious area= 4,411 SF Detention Req'd Per Edmonds Table 1= 112 CF = 838.76 Gal. "2,000" Gal Detention Tank (Modified Utility Vault CCP 612 per CUZ Conc.) Inside L = 12' Inside W = 6 Depth = �A' Gal/ft 538.6 Volume 388 CF = 2,908 Gal available Air Space 0. 5' = 134 Gal Detention Volume= 3.9'=2,10OGal Dead Storage = 1.0' = 538.6 Gal Restrictor size = 7/8" per City of Edmonds Restrictor size per SBUH Engineered Design 11/16" J.C.McDonnell Engineering, PS 4 E 0 SITE HYDRAULIC ANALYSIS Drywell Sizing Calculation The intent is to provide for infiltration of the rooftop stormwater from this building up to the 100-year event. This is done be selecting an infiltration system of sufficient size to dissipate the metered flow from the detention vault. We have previously selected a design appl ication rate of 2.0 in/hour after including a Safety Factor of 2.0. A Stage Storage table was developed for a drywell field of 100 LF of 2' x 2' trench. The Staged Storage table was entered into the Santa Barbara Unit Hydrograph model routines. The performance hydrographs for the detention tank were then routed through the drywell system. The I 00-foot drainfield was determined to absorb the released hydrographs up to the 100-year event. The model results and the Stage Storage Table are provided in the appropriate section of the Appendix. DOWNSTREAM CONDITIONS Site detention will discharge by a 4" pipe conveyance to a drywell in the rear yard area as described above. There is no piped outlet available on the downstream property. Currently the rear yard drops in elevation to a low point at or slightly east of the property line. The grade begins to rise in the neighbor's yard to the east. The overall terrain slopes North & east. Since the rear yards are lower than the respective houses, it seems reasonable to suppose that any surface flows that may occur during highly intense storm events might pond in the yard areas without harming any structures. The proposed design under foreseeable conditions including an isolated 100-year peak event will be * dissipated into the soil without a noticeable impact on downstream properties. The project is small relative to the lot size in question and the neighborhood is currently designed to a density of I unit per 0.4 acres. Therefore, we do not expect the stormwater to appear on the surface in foreseeable conditions as long as reasonable care & maintenance is take to prevent the drywells from silting up or plugging. The soils were examined on a winter day in early March 2009 when winter high water table conditions would reasonably be expected to apply. The soils were observed to be well draining down to the hard pan layers as indicated. J.C.McDonnell Engineering, PS 5 ENGINEERING REPORT APPENDICES J.C.McDonnell Engineering, PS 0 0 1. Site Vicinity Map J.C.McDonnell Engineering, PS VICINITY MAP IL a 4, :71 7 2151h St # I . , 1p IJ� �11' "S a 'Ic"' , I 77j- - �: -7f; M Sw At IIJ c__ C 2009 Ugj "i' W-V 6�6;jo U., MAY 10611 90w_ tlp! siv Sw tw A, M600NNCI-1- CN61NCCP-1N6 PC 4onsulting Civil Cn9ineers (0406- ?-I(P" 5w, stf, -30(p Mountlaft Torraco, WA. WO (42-5) 144-oqt5 (Tot) (42.5) 144-oq4(p (FAX) f; -mail: jotdoateverizon.not 2 St. L45W ii 2-th. Stl� Tom Matuszeuski 21429 — 84h Avenue W Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: I . Photobase I 9 LI 2. Aerial Topography Map J.C.McDonnell Engineering, PS USGS BASIN TOPOGRAPHY 7 A P. --fill fA 5 �AV r"i _A j� ? re A N] 4 J Now lassos.r, 44-1 74 '04 Wn -A `,436,. o F. % so# L LM Tom Matuszeuski Ir4. M400NIVCI-L cN61Nccp_1N6 P6 21429 — 84hAvenue W 60nBUIth7g 6ivil Ci7gineers Edmonds, WA WPOS- 2.10 $W, $te -30(p Mountlalco Torraco, WK qSO43 COMMONNESS (4?.5) 144-oqi5 (Te.1) (4?-5) 144-oq4(p (FA9) SCALE: None DATE: SHEET: e -mail: jt�mcdonZ@vorizon.not JOB NUMBER: FILE NAME: BY: Photobase 2 I BUILDING SITE let x - :5 Ij -,AN. AN 46 4r t �-% , *4 . - :1 XIC. WPONNea CN61NccP-1N6 PIC i5onsuffing -ivil Cngineers (P(006- z1v cow, cou 30(p Mountialce Terraco, WA, qSO43 (4z5) 144-06 (Tot) (42-5) 144-oq4(p (FAX) 6-tnai1:j0cdonz@verizon.not Tom Matuszeuski 21429 - 80Avenue W Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: I Photobase 3 9 � 0 DOWNSTREAM OF DRYWELL SITE 2 trv.A. �' - _' — -' -' —1 !NNW, . 'A44, '4 Al� "Vo X4. MCP0NPVCLL CN61N6CP4N6 PC i5onsulfing civil engineers (0('06- Zlv .5w, $to 30(p MounflaYo Terrace, VA qftO (4z5) 144-o$5 (Tol) (4?-5) i44-0q4(p (FAK) e -mail: j4ndonuverizon.net Tom Matuszeuski 21429 — 84th Avenue W I Edmonds, WA SCALE: None DATE: SHEET: JOB NUMBER: FILE NAME: BY: Photobase 5 7.7 --'�2,009/03/09 ! US- Uyl - - - -�-- � ZZ 0 3. Edmonds Drainage Calculations & Exhibit a. Detention Sizing Calculations b. Infiltration Sizing Calculations J.C.McDonnell Engineering, PS 9 a. Detention Sizing Calculations J.C.McDonnell Engineering, PS 10 9 0 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 1 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B002 NAME: 2 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 1.50 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.01 cfs VOL: 0.00 Ac-ft TIME: 490 min BASIN ID: B010 NAME: 10 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 2.20 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.02 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: B025 NAME: 25 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 2.80 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION-COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400. impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min IMP 0.00 Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min J.C.McDonnell Engineering, PS I I 9 0 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 2 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B100 NAME: 100 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 3.30 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D002 NAME: 2 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 1.50 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: D010 NAME: 10 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.20 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN� .... 0.100 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.04 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D025 NAME: 25 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.80 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.06 cfs VOL: 0.02 Ac-ft TIME: 480 min J.C.McDonnell Engineering, PS 12 3/16/09 2:59:43 pm. J.C. McDonnell & Associates page 3 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: D100 NAME: 100 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: RAINFALL TYPE .... TYPElA PRECIPITATION .... 3.30 inches AREA..: TIME INTERVAL .... 10.00 min CN .... TC .... ABSTRACTION COEFF: 0.20 PEAK RATE: 0.07 cfs VOL: 0.03 Ac-ft TIME 0.00 cfs PERV IMP 0.00 Acres 0.10 Acres 0.00 98.00 0.00 min 7.00 min 480 min J.C.McDonnell Engineering, PS 13 0- 0 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 4 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF CONTRIB NUM RATE PEAK HYDRO AREA CFS MIN. CF\ACFT ACRES UNDEVELOPED 1 0.006 490 166 CF 0.10 2-YEAR 2 0.016 480 346 CF 0.10 10-YEAR 3 0.026 480 521 CF 0.10 25-YEAR 4 0.034 480 676 CF 0.10 100-YEAR DEVELOPED 5 0.030 480 469 CF 0.10 2-YEAR 6 0.045 480 723 CF 0.10 10-YEAR 7 0.058 480 942 CF 0.10 25-YEAR 8 0.069 480 1125 CF 0.10 100-YEAR DETENTION VAULT PERFORMANCE 9 0.012 540 397 CF 0.10 2-YEAR 10 0.017 550 651 CF 0.10 10-YEAR 11 0.020 560 870 CF 0.10 25-YEAR 12 0.023 560 1053 CF 0.10 100-YEAR INFILTRATION APPLICATION RATES TO SOIL SURFACE Q= ZERO CFS J.C.McDonnell Engineering, PS 14 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 5 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE STORAGE TABLE RECTANGULAR VAULT ID.No. 200OG Description: Length: 12.00 ft. Width: 6.00 ft. voids: 1.000 STAGE --STORAGE STAGE -STORAGE- STAGE --STORAGE ---- > STAGE -STORAGE-- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- 91.40 0.0000 0.0000 92.70 93.600 0.0021 94.00 187.20 0.0043 95.30 280.80 0.0064 91.50 7.2000 0.0002 92.80 100.80 0.0023 94.10 194.40 0.0045 95.40 288.00 0.0066 91.60 14.400 0.0003 92.90 108.00 0.0025 94.20 201.60 0.0046 95.50 295.20 0.0068 91.70 21.600 0.0005 93.00 115.20 0.0026 94.30 208.80 0.0048 95.60 302.40 0.0069 91.80 28.800 0.0007 93.10 122.40 0.0028 94.40 216.00 0.0050 95.70 309.60 0.0071 91.90 36.000 0.0008 93.20 129.60 0.0030 94.50 223.20 0.0051 95.80 316.80 0.0073 92.00 43.200 0.0010 93.30 136.80 0.0031 94.60 230.40 0.0053 95.90 324.00 0.0074 92.10 50.400 0.0012 93.40 144.00 0.0033 94.70 237.60 0.0055 96.00 331.20 0.0076 92.20 57.600 0.0013 93.50 151.20 0.0035 94.80 244.80 0.0056 96.10 338.40 0.0078 92.30 64.800 0.0015 93.60 158.40 0.0036 94.90 252.00 0.0058 96.20 345.60 0.0079 92.40 72.000 0.0017 93.70 165.60 0.0038 95.00 259.20 0.0060 96.30 352.80 0.0081 92.50 79.200 0.0018 93.80 172.80 0.0040 95.10 266.40 0.0061 96.30 352.80 0.0081 92.60 86.400 0.0020 93.90 180.00 0.0041 95.20 273.60 0.0063 J.C.McDonnell Engineering, PS 15 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 6 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. 200OGx Description: Design 25 yr Outle�t Elev: 92.40 Elev: 91.90 ft Orifice Diameter: 0.6880 in. STAGE <DISCHARGE> STAGE <DISCHARGE> STAGE -DISCHARGE- STAGE DISCHARGE> (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- 92.40 0.0000 93.40 0.0128 94.40 0.0182 95.40 0.0222 92.50 0.0041 93.50 0.0135 94.50 0.0186 95.50 0.0226 92.60 0.0057 93.60 0.0141 94.60 0.0191 95.60 0.0230 92.70 0.0070. 93.70 0.0146 94.70 0.0195 95.70 0.0233 92.80 0.0081 93.80 0.0152 94.80 0.0199 95.80 0.0237 92.90 0.0091 93.90 0.0157 94.90 0.0203 95.90 0.0240 93.00 0.0099 94.00 0.0162 95.00 0.0207 96.00 0.0244 93.10 0.0107 94.10 0.0167 95.10 0.0211 96.10 0.0247 93.20 0.0115 94.20 0.0172 95.20 0.0215 96.20 0.0250 93.30 0.0122 94.30 0.0177 95.30 0.0219 96.30 0.0254 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 7 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16r 2009 STAGE DISCHARGE TABLE RISER DISCHARGE ID No. Risl Description: Riser Diameter (in): 4.00 elev: 95.80 ft Weir Coefficient ... 9.739 height: 96.30 ft Orif Coefficient ... 3.782 increm: 0.10 ft STAGE <-DISCHARGE- STAGE <-DISCHARGE--> STAGE <-DISCHARGE-> STAGE <DISCHARGE --- > (ft) --- ds -- ------- (ft) --- ds -- ------- (ft) --- ds -- ------- (ft) --- ds -- ------- - 95.80 0.0000 95.90 0.1329 96.10 0.2302 96.30 0.2971 95.80 0.0000 96.00 0.1879 96.20 0.2658 96.30 0.2971 J.C.McDonnell Engineering, PS 16 3/16/09 2:59:43 pm J.C. McDonnell & Associates page 8 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. combol Description: Structure: 200OGx Structure: Structure: Risl Structure: Structure: STAGE <--DISCHARGE- STAGE -DISCHARGE STAGE -DISCHARGE STAGE -DISCHARGE (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- (FT) --- CFS -- ------- 92.40 0.0000 93.70 0.0146 95.00 0.0207 96.30 0.3225 92.50 0.0041 93.80 0.0152 95.10 0,0211 96.40 0.3512 92.60 0.0057 93.90 0.0157 95.20 0.0215 96.50 0.3776 92.70 0.0070 94.00 0.0162 95.30 0.0219 96.60 0.4022 92.80 0.0081 94.10 0.0167 95.40 0.0222 96.70 0.4253 92.90 0.0091 94.20 0.0172 95.50 0.0226 96.80 0.4472 93.00 0.0099 94.30 0.0177 95.60 0.0230 96.90 0.4680 93.10 0.0107 94.40 0.0182 95.70 0.0233 97.00 0.4879 93.20 0.0115 94.50 0.0186 95.80 0.0237 97.10 0.5070 93.30 0.0122 94.60 0.0191 95.90 0.1569 97.13 0.5126 93.40 0.0128 94.70 0.0195 96.00 0.2123 93.50 0.0135 94.80 0.0199 96.10 0.2549 93.60 0.0141 94.90 0.0203 96.20 0.2908 J.C.McDonnell Engineering, PS 17 0 3/16/09 2:59:45 PM J.C. MCDONNELL & ASSOCIATES PAGE 9 MATUSZEWSKI SINGLE FAMILY EDMONDS ROOFTOP 200OG DETENTION MARCH 16,2009 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE < -------- DESCRIPTION --------- > (CFS) (CFS) --ID- --ID- <-STAGE> ID (CFS) VOL (CF) 2-YEAR ...................... 0.01 0.032000GCOMBOI 93.28 9 0.01 135.66CF 10-YEAR ...................... 0.02 0.04 200OG COMBOI 94.10 10 0.02 194.58 CF 25-YEAR ...................... 0.03 0.062000GCOMBOl 94.8911 0.02 251.01CF 100-YEAR ..................... 0.03 0.072000GCOMBOI 95.5812 0.02 301.09CF J.C.McDonnell Engineering, PS 18 0 0 a. Infiltration Sizing Calculations & Staged Storage Table J.C.McDonnell Engineering, PS 19 3/16/09 3:19:0 pm J.C. McDonnell & Associates MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B002 NAME: 2 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 1.50 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION COEFF:- 0.20 TcReach - Sheet L: 187.00 ns: ' 0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.01 cfs VOL: 0.00 Ac-ft TIME: 490 min BASIN ID: B010 NAME: 10 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 2.20 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.,50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.02 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: B025 NAME: 25 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV PRECIPITATION .... 2.80 inches AREA..: 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 TC .... 17.89 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min page 1 IMP 0.00 Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min J.C.McDonnell Engineering, PS 20 0 0 3/16/09 3:19:0 pm J.C. McDonnell & Associates page 2 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: B100 NAME: 100 YEAR UNDEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 3.30 inches AREA..: 0.10 Acres 0.00 Acres TIME INTERVAL .... 10.00 min CN .... 85.00 0.00 TC .... 17.89 min 0.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 187.00 ns:0.1500 p2yr: 1.50 s:0.0400 impTcReach - Sheet L: 50.00 ns:0.0110 p2yr: 1.50 s:0.0200 impTcReach - Sheet L: 137.00 ns:0.1500 p2yr: 1.50 s:0.0500 PEAK RATE: 0.03 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D002 NAME: 2 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 1.50 inches AREA..: 0.00-Acres 0.10 Acres TIME INTERVAL....': 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.03 cfs VOL: 0.01 Ac-ft TIME: 480 min BASIN ID: D010 NAME: 10 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.20 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.04 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: D025 NAME: 25 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 2.80 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.06 cfs VOL: 0.02 Ac-ft TIME: 480 min J.C.McDonnell Engifieering, PS 21 3/16/09 3:19:0 pm J.C. McDonnell & Associates page 3 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 BASIN SUMMARY BASIN ID: D100 NAME: 100 YEAR DEVELOPED SBUH METHODOLOGY TOTAL AREA ....... 0.10 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... TYPElA PERV IMP PRECIPITATION .... 3.30 inches AREA..: 0.00 Acres 0.10 Acres TIME INTERVAL .... 10.00 min CN .... 0.00 98.00 TC .... 0.00 min 7.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.07 cfs VOL: 0.03 Ac-ft TIME: 480 min J.C.McDonnell Engineering, PS 22 3/16/09 3:19:0 pm J.C. McDonnell & Associates MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF CONTRIB NUM RATE PEAK HYDRO AREA CFS MIN. CF\ACFT ACRES UNDEVELOPED ROOFTOP RUNOFF 1 0.006 490 166 CF 0.10 2 0.016 480 346 CF 0.10 3 0.026 480 521 CF 0.10 4 0.034 480 676 CF 0.10 DEVELOPED ROOFTOP RUNOFF 5 0.030 480 469 CF 0.10 6 0.045 480 723 CF 0.10 7 0.058 480 942 CF 0.10 8 0.069 480 1125 CF 0.10 DETENTION VAULT PERFORMANCE 9 0.012 540 397 CF 0.10 27year 10 0.017 550 651 CF 0.10 10-year 11 0.020 560 870 CF 0.10 25-year 12 0.023 560 1053 CF 0.10 100-year INFILTRATION APPLICATION RATES TO SOIL SURFACE Q= ZERO CFS 14 0.011 620 397 CF 0.10 2-year 15 0.014 730 651 CF 0.10 10-year 16 0.016 810 870 CF 0.10 25-year 17 0.017 850 1053 CF 0.10 100-year page 4 J.C.McDonnell Engineering, PS 23 9 0 3/16/09 3:19:0 pm J.C. McDonnell & Associates page 5 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE STORAGE TABLE CUSTOM STORAGE ID No. 2' Description: 100' - 2-foot trench STAGE < ---- STORAGE--- STAGE -STORAGE- STAGE < ---- STORAGE--- STAGE <STORAGE-> (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- (FT) --- CF--- --AC-FT- 92.00 0.0000 0.0000 92.10 0.9000 0.0000 92.20 1.8000 0.0000 92.30 4.1240 0.0001 92.40 6.8040 0.0002 92.50 10.544 0.0002 92.60 14.990 0.0003 92.70 19.969 0.0005 92.80 26.191 0.0006 92.90 32.590 0.0007 93.00 40.590 0.0009 93.10 48.590 0.0011 93.20 58.192 0.0013 93.30 67.972 0.0016 93.40 78.996 0.0018 93.50 90.552 0.0021 93.60 102.82 0.0024 93.70 116.15 0.0027 93.80 130.24 0.0030 93.90 147.37 0.0034 94.00 164.50 0.0038 94.00 164.50 0.0038 3/16/09 3:19:0 pm J.C. McDonnell & Associates page 6 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 STAGE DISCHARGE TABLE DISCHARGE LIST ID No. 2' Description: 100' - 2-foot trench STAGE <--DISCHARGE- STAGE <--DISCHARGE-STAGE <--DISCHARGE- STAGE DISCHARGE - (FT) --- CFS -- ------- (FT) --- CFS -- ----- (FT) --- CFS -- ----- (FT) --- CFS -- ------- 92.00 0.0000 92.60 0.0117 93.11 0.0140 93.70 0.0166 92.10 0.0045 92.67 0.0120 93.20 0.0144 93.78 0.0170 92.20 0.0091 92.70 0.0121 93.30 0.0149 93.80 0.0172 92.22 0.0100 92.80 0.0126 93.33 0.0150 93.90 0.0181 92.30 0.0104 92.89 0.0130 93.40 0.0153 94.00 0.0190 92.40 0.0108 92.90 0.0130 93.50 0.0157 94.00 0.0190 92.44 0.0110 93.00 0.0135 93.56 0.0160 92.50 0.0113 93.10 0.0140 93.60 0.0162 J.C.McDonnell Engineering, PS 24 3/16/09 3:19:2 pm J.C. McDonnell & A ' ssociates page 7 MATUSZEWSKI SINGLE FAMILY Edmonds Rooftop 200OG Detention March 16, 2009 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE < --- DESCRIPTION --- > (CFS)(CFS) --ID- --ID- <-STAGE> ID (CFS) VOL (CF) DISCHARGE TO GROUND SURFACE WILL BE ZERO IN THE 100-YEAR EVENT 2-YEAR ....................... 0.01 0.01 2' 2' 92.47 14 0.01 9.42 CF 10-YEAR ...................... 0.01 0.02 2' 2' 93.05 15 0.01 44.73 CF 25-YEAR ...................... 0.01 . 0.02 2' 2' 93.48 16 0.02 88.42 CF 100-YEAR ..................... 0.01 0.02 2' 2' 93.81 17 0.02 131.72 CF J.C.McDonnell Engineering, PS 25 Design Parameters: Trench Width (W)= Trench Depth = Trench Length = Void Ratio (V,) = Field Pere Rate = Safety Factor = Bottom Trench Elevation = Trench Area Velocitv of infiltration (v) = 2 2 100 40 15 2 100 MATUSZEWSKI SINGLE FAMILY EDMONDS, SNOHOMISH COUNTY, WA. reet VOID SPACE 40% reet reet Alderwood GSL Permeabilitv percent minutes/in h AVERAGE MAXIMUM DESIGN 200 fe 4.62963E-05 feet I second = 1/(Field Pere Rate rate x Safetv Factnrl IN/HR 2.0-6.0 15 min/in 10 min/in 30 MfN/fN Design Depth (H) ft Trench x-section (0.5)*2H+W ft Total Surface Area (A) ft 2 Wetted Trench volume (Vw) ft, Actual Volume V, * Vw ft 3 Qflow into ground Qfl. = v*A W/sec Elevation 0.00 0 0 0 0.00 0 2.0 0.22 2.22 222.22 44.44 17.78 0.010 2.2 0.44 2.44 244.44 88.88 35.55 0.011 2.4 0.67 2.67 266.66 133.32 53.33 0.012 2.7 0.89 2.89 288.88 177.76 71.10 0.013 2.9 1.11 3.11 311.1 222.20 88.88 0.014 3.1 1.33 3.33 333.32 266.64 106.66 0.015 3.3 1.56 3.56 355.54 311.08 124.43 0.016 3.6 1.78 3.78 377.76 355.52 142.21 0.017 3.8 2.00 4.00 399.98 399.96 159.98 0.019 4.0 0 0 0 0 4. Available Soil Data J.C.McDonnell Engineering, PS 26 0 K M rn SO ch an, M V) (7 C I 0 cn M M —i z CO rn X 0i) 0 This soll's—ey map Was compiled'by the'U.S.'DeDertment afAgriculture,,Soll Conservation Service, and cooperating agencies. Bona maps wo wthaphotoatophs prepared by the State of Washington, Department of Natural Resources from 1973 and,1974 serial photography. Coordinate grid tic" and land division corners. It shown. are approximately positioned. 183 Snohomish County Area, Washington TABLE 14.--PHYSICAL AND'CHEMICAL PROPERTIES OF SOILS [The symbol < means less than; > means more than. Entries under "Erosion factors--T" apply to the entire profile. Entries under "Organic matter" apply only to the surface 1 . ayer. Absence of an entry indicates that data were not available or were not estimated] swell i factors Organic matter soil name and IDepth,Clay <2mmj Permeability Available Soil I Shrink - water capacity Ireaction! potential I map symbol K T n Pct 19 29 3 ---------- 1 o-7 1 5-10 Alderwood 1 7-351 5-10 1 35 1 4*: Alderwood ------- 1 0-7 1 5-10 1 7-351 5-10 1 35 1 --- A, Everett --------- 1 0-6 1 5-10 1 1 6-181 5-10 1 118-601 o-5 5*, 6*: Alderwood ------- 1 0-7 1 5-10 i 1 7-351 5-10 1 35 1 N Urban land. -9 15-30 1 7 ---------------- 0 1 Bellingham 1 9-601 40-60 1 -6 1 -35 -------- 1 0 , . 27 am 1 6-421 35-45 -601 12-30 Variant 142 9, 10, 11 -------- 0-8 i --- 4 Cathcart 8-351 135-601, I 12*. Cryohemists 13 --------------- 1 0-9 1 10-15 1 custer 1 9-351 0-10 1 135-601 0-10 1 0-2 14 --------------- 1 Elwell 1 2-231 --- 123-273' 27 1 15-: Elwell ---------- 1 0-2 1 1 2-231 123-271 27 1 --- Olomount -------- 1 0-2 1 1 2-181 118-321 --- 32 1 16*- -2 ElwVll ---------- 1 0 1 1 2-231 123-271 1 27 1 --- See footnote at end of table. 2.0-6.0 0.07-0-11 2.0-6 0 0.07 -0-11 .2.o-6.0 0.07-0-11 2.0-6.0 . -0 0 07 .11 2.0-6.0 0.08-0.12 6.0-20 0.05-0-08 6.0-20 0.02-0.05 2.o-6.0 0.07-0-11 2.o-6.0 1 0.07-0-11 0.2-0.6 0.20-0.24 0.06-0.2 0.20-0.24 0.2-0.6 0.19-0.21 0.06-0.2 0.18-0.21 0.2-0.6 0.14-0.16 0.6-2.0 0.18-0.20 o.6-2.0 0.13-0-17 0.6-2.0 0.14-0.17 2.0-6.0 0.13-0-15 0.2-0.6 0.06-0.08 >20 0.06-0.09 0.6-2.0 0.22-0.26 0.6-2.0 0.19-0.23 0.6-2.0 0.09-0-13 0.6-2.0 0,22-0.26 0.6-2.0 0.19-0.23' 0.6-2.0 0.09-0.13 0.6-2.0 0.13-0-16 o.6-2.0 i 0.11-0.14 0.6-2.0 0.08-0.10 0.6-2.0 0.22-0.26 o.6-2.0 .0.19-0.23 0.6-2.0 0.09-0.13 P 1 11 1. 15.1-6.5 !Low ------------ 10.201 2 ,-5.6-6.5 Mow ------------ 10.201 1 --------------- 1 15.1-6.5 !Low ------------ 10.201 2 15.6-6.5 !Low ------------ 10.201 i--------------- 1 15.6-6.5 !Low ------------ 10.1711 1 15.6-6.5 !Low ------------ 10-101 15.6-6.5 !Low ------------ 10.101, 15.1-6.5 !Low ------------ 10.201 2 15.6-6.5 !Low ------------ 10.201 i--------------- 1 15.6-6.5 Mow ------------ 10-321 5 16.1-7.3 !High ------------ 10.241, 15.1-5.5 IModerate ------- 10.321 5 14.5-5.5 Nigh ----------- 10.321 14.5-5.0 !Moderate ------- 10-321 14.5-6.o !Low ------------ 10-371 5 15.1-6.5 !Low ------------ 10.431 15.1-6.5 !Low ------------- 10-371 1 11 15.6-6.0 !Low ------------ 10.281 5 15.1-5.5 Mow ------------ 10.241 15.6-6.0 !Low ------------ 10.101, 13.6-5.5 !Low ------------ 10.371 2 15.1-5.5 Mow ------------ 10:431 15.1-5.5 !Low ------------ 10.281 i--------------- 1 13.6-5.5 !Low ------------ 10-371 2 15.1-5.5 !Low ------------ 10.431 1 .5.1-5.5 .,'Low ------------ 110.281 --------------- 2 15 1 .1-5.5 ',Low ------------- so.241 15.6-6.0 !Low ------------ 10.281 15.6-6.5 !Low -------------- 0.28, --------------- 1 13.6-5.5 !Low ------------ 10-371 2 15.1-5.5 Mow ------------ 10.431 15.1-5.5 Mow ------------ 10.28, --------------- 5-10 5-10 10-15 03-12-2009 02:45PM FROWCUZ CONCR ODUCTS 360-435-6575 T-238 P-002/002 F-986 f"N., P_ -5531 Fax (360) 435-8575 19604 - 67th Ave NE Arlington. Wa_ 98223 Tel.ephOne (360) 435 152' I 62,011 12'- 0#1 51.5.1 ., Sig 71-511 6- • CONCRETE ; 25 DAY COMPRESSIVE STRENGTH Vc - 4600 pal • REBAR : #4 ASTM A-GIS GRADE 60 MESH ; ASTM A-185 GRADE 88 DESIGN ; ASTM "57 116UNIMUM STRUCTURAL DESION LOADING FOR UNDERGROUND PRECA3T CONCRETF. UTILITY STRUCTURES- LOAoS : H-2a TRUCK WHEEL wl 30% PAPACT FOR AASHTO RFMFORCELKQ FLACWENT : P4 REBAR 121 O.C. THROUGHOUT. IN BASE AND TOP SECTIONS. 4x4 / 4 GAUGE MESH AROUND wl 2 44 REGAR RUNMNG PARALLEL ALONG BELL JOINT$ jOjNT MATERIAL MEETS FEDERAL SPECIFICATIONS 66-S-00210. ASHTO M-1950 AND ASTM C990 HATCHES PER DISTRICT SPECIFICATIONS I OfInO02