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20020239.pdfan DATE RECEII E PERMITEXPIRES P MIT CITY OF EDMONDS �U.SFE 'ER UM"R CONSTRUCTION PERMIT APPLICATION JOB "'T775 ADDAES' N OWNER RAM AME Op-muSIN as Q I- M(Z% S PLAT NAMFISUBDIVISION N7 LOT NO, LID NO O'JWSD MAILING ADDRESS .7 LID FEE $ PUBLIC RIGHT OF WAY PER OFFICIAL SmIET MAP III r- �ad Pa.,: Fare CITY X ZIP TELEPHONE EXISTING PROPOSED— =rrhslad 13 P.,as.a 13 REQUIRED DEDICATION— IT ti-g— ass 'reed 0 NAME METER SIZ LINJ� SIZE I No. OF'j;RES 11V REQUIRED to YES No 13 PE.A.. OWNERICONTRACTOR-RESPONSIBLE FOR EROSION CONTR HUDRAINAGE ADDRESS FIRE REVIEWPI1 By AT F. ciCITY EP�ION�o l 616111 1,1TIC q- 30q 0 , STATE LICENSE NUMBER EXPIRATION VARIANCE OR CU SHORELINE OR ADS# INGPECTI N 0 REOG PDO D OSTED 'JA,-tZC—t-oI�?-VA E3YES [31,10 j'PROPERIN'TAX ACCOUNT PARCEL NO. SEPA REVIEW COMPLETE EXEMPT SIGN AREA A�7 PROPOSED HEIGHT ALLOWED PROPOSE 5 210 3 c, C)o -� C) 4/4 EXF , J� 1 N/A _GI ?I 2 1 NEW RESIDENTIAL 'OD�U.1013111G I ME.11 LIT ALLOWED PROPOSED RE IRE SETBACK' IFTI Plop SED SETBACK$ (Fr.) NTt SIDE REAR FRON LJ,71DI BEAR ADDITION COMMERCIAL COMPLIANCE OR . I 7'1,i 144k. CHANGE OF USE REMODEL APARTMENT SIGN PARKING REGC LOT AREA ROVID U NO RE E rl REPAIR FENCE CYOS X FT) RE? 0 DEMOLISH 0 TANK Le�YAV rt�,W NID FI4ZDA-Lr-- AVIF-7-- ARAGE JOA-P-111` RETAINING WAU. 0 ROOKERY RENEWAL - - �1-&t Me-, OWE OF USE. BUSINESS OR ACTIVITY) EXPLAIN: WE N�zw '.�- P Q CHECKED try ITY E 01 CONSTRUCTION jCq� NUMBER OF NDUIME EINGF WANT 0 STORIES UNITS DESCRIBE WORK TO BE DONE VAUJATION $ LU r in rDescrlpflon FEE Description FEE 03C 'Pt'O Plan Check hT;5 HVGURCE GILAVNG % ",T 'jpjl� Building ".pri PIAN CHECK NO: 2 Plumbing GAP VESTED E THIS PERMIT AUTHORMS ONLY THE ORKNOTED. THIS PERMIT COVERS WORK TO Mechanical DONE ON P I 1: 01 11 VATE PROPERTY ONLY. ANY CONSTIR 1*1411,1111""uc Is ONAIN (CURSS, SIDEWALKS, DRIVEWAYS MARQUEES, ETC.) WILL Grading 1 C,7 Recording Fee SEPARATEPERMiSSION. 2 9 RE IT APPLICATION: ISO DAYS USE - E YEAR - PROVIDE A. PERUM UMM I 'I-. D WORK HISTAITTEO WITHIN INDAYS SEEBACKOPPINK PERMIT FOR MORE INFORMATION Engr. Review City Surcharge EngE. Inspection state Surcharge 'APPLICANT ON BEHALF (IF His OR HER SPOUSE, HEIRS. ASSIGNS AND SUCCESORS R IN INTE EST, AGREES TO INDEMNIFY DEFEND AND HOLD HARMLESS THE CITY OF Traffic Mitigation Plan Chk Deposit EDMONDS, WASHINGTON ' ITS OFFICIALS, EMPLOYEES, AND AGENTS FROM ANY AND ALL CLAIMS Fort DAMAGES OF WHATEVER NATURE, ARISING DIRECTLY OR INDIRECTLY FROM THE I SUANCE OF THIS PERMIT ISSUANCE 01 THIS PERMIT GFIAIL Nor BE DEEMED TO MODIFY, WAIVE OR REDUCE ANY REOUIREMENT OF A Y CITY ORDINANCE Fire Review Receipt # KA / Fire Inspection Total Amount Due 3�41 0 N C se OR LIMIT IN AM WAY THE CHYS ABILITY TO ENFOR E ANY ORDINANCE PROVISION - Landscapeinsp. --IpE —#� I HEREBY ACKNOWLE GE THAT I HAVE READ THIS APPLICATION; THAT THE INFORMATION GIVEN IS CORRECT. AND THAT I AM TLIE OWNER. OR THE DULY AUTHORIZED AGENT OF APPLICATION APPROVAL THE OWNE . A THO'COMILY WITH CITY AND STATE I -Awl 11GULATING CONSTTIUC TION; AND IN DO G TH ORK AUTH.SVE. THEREBY. Is PERSON WILL E EMPLOYED IN VIOLATION T1 a " .0. CODE OF THE EITATE OF WASHINGTON RELATING TO WORKMENS S ION INSURANCE AND RCW 1827. CALL FOR INSPECTION (4251 11seapplicatian IsIsi. perb.,111,ighed by We B11IdiI9 Offical or his/her DepIty: We Feet are paid, ard Tocerplar8oklmledgedilsipaid, provided. OFF JAILS SIGNATURE DATE "iIGNATUR AGENT) ONED III-lopt, lf.401=1 �� 771-0220 ft��T-AUE- BY DATE ATTENt" EXT 1333 IT IS UNLAWFUL TO USE OR OCCUPY A BUILDING OR STRUCTURE UNTIL A FINAL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTIFI- 771-0221 ------ OREGINAI � FILE YELLOW - NSPE� CATE OF OCCUPANCY HAS BEEN GRANTED, UBC SECTION 109 FAX PINK - OWNER COLD � ASSESSOR 10/01 z M M 0 80 a M M -z W 0 -n IT RR M - Cl) 0 r- 0 M a (a 91:0 Q 0 z �2 ri) z 9 0 rn NOTICE. IF THE DOCUMENT IN THIS FRAME IS LESS CLEAR THAN THIS 40TICE IT IS DUE TO THE QUALITY OF THE DOCUMENT C) M -E IMPERVIGUS SURTAC CALCS; *41L 87.42' R 390 C:) w > C= LLJ n ED tt f P-p-d Suit." R, ' . 2,555 i;f, P-p-d V-W� Ft— 1,1549 -f, -P 7 P p-d G-g. � 454 F. 45 4 Fr �"r� F 0.tt�. N :] 15' _IBAC�S SE CD (1) CD u c) w ;K 0 Co -i Lu (D P rI . L,3W ft. P-p-d BrI.-y 1,353 P-p-d Vaw-y� 134 sf. 0 -j W LI- 03 P P opospd Umk, 114 sf. POP h - IL16 5F- ux (y) p- d v.r P,op-d overed C:) RELENT CALM W n LL A -103' *11" CD 0 Cu rAvE.GRAUE PROPOSED - Lj C) > co U 101.75' .75' ACTUAL CRADE 120,25- RESIDENCE 1649 SQ. u < o-, ::D U, .,75V HAXD4UM GqAVE 12f X.M G� I LOT COVERAGE Fw� <r 3,610 SiXT. (47YD 0 ry u LOT AREA PROPOSED 7.5' V K GARAGE L� 8,059 SaM AY 454 SO I.. A�-M� P.rc-I 4 C .101, r4 Z 6- w z 2703-360-03a-4400 -10 7.5' 0 T U, LOT SLOPE u 7 LESS THM 5Z w bj ()J 20' ov D DRIVEWAY u w SCALE I'=20' DRAINAGE PLAN ACCORDING TO DATM POINT -IM' CM 65, NORTH OF <: SP SEMACKS. FMPERTY LINE c FRON I 15' DRIVEWAY EASEMENT ON LOT B IL FOR A,B AND C TO FIRDALE AVE. W- IT -H HEIGHT .. ....... . . IMPERVIOUS SURFACE CALCS. Proposed Bulldtmq Roof OutUme s 2,555 sf. Prop ... d Hot. Floor � 1,649 f. 'lop . d Gr.g. - 454 F. P P:se r. ed D,Neway 1,353 sf, Proposed Watkways 134 SF. Proposed Deck , 114 sf. Proposed Covered Porch , 106 of. HEIGHT CALCS. A :,1.13' B I C .10' D ,or AVE. GRADE = 101.75' ACTUAL GRADE 12025' MAXIMUM GRADE 126,75'1 LOT COVERAGE - 3,610 SQ.FT. (47%) LOT AREA 8,058 SOFT. Tax Account Parcet # 2703-360-030-4400 LOT SL13PE LESS THAN 5X C.0 1 C) LA (D cD 0— w _j — z C:) Cu Lli C) U > CC) < M L'i z L) CD CLI ED z m 2: ce) f::l (U Lj C—) LLJ Ctj I (A NOTICE: IF THE DOCUMENT IN THIS FRAME IS LESS CLEAR THAN THIS NOTICE IT IS DUE TO THE QUALITY OF THE DOCUMENT. 3loa 3&o C:) GRADING CALCSI LCCEPPTT HTLINE 87,42' R I lym CD 490% P9 VIEW SECTION I SATI91,111AA TER/SEI VER DATHICT AVE CUT llf� 3DR 3 FN " _-15' CUBIC YARDS 3CH 40 SETBACKS ## SECTION It Y -120, 20' c:) m i:810 CD AVG, CUT Of �10 CUBIC YARDS = 73.11 FIT �a LLJ (y) 44- ITOTAL CUBIC YARDS 119.15 SCALE 1'=20' 14' al U M 7.5� �9-1 O� CD 1-- LOT COVERAGE 1 Tax Account Parcel# it 27.5' ":1: CD (IL oi 3,810 SOFT. (47X) 2703-360-030-4400 SECTION 11 21.51 7.5' Ic LOT AREA LOT SLOPE - DRAINAGE PLAN 14' z �i: c) PROPOSED 0 cu 8,059 SOFT. LESS T14AN 5% ACCORDING TO RESIDENCE — Lj C:) SP 97-009 1-- > co u FILTER FARRIC ::) < O's SECMED TO 2- X e SECTION I 14 VIRE FABRIC Li E.— _j B. T 5' 'EUIVALENT 14' 37' z m E3 fy- 22, 7.5' A, U W Lk Li- fz� AY �U z w 0` 75' U -Y < I P:l 2--2s .11 - < Li FILTER FABRIC FMC THC —CE. L ICD le Y Li 10 DRIVEW Y 0." —i < u n 7" wL u LLUI u DATUM POINT �1001 CB 65' NORTH OF CL 9! PROPERTY LINE .13 ca < --j &L D)ae�--raq -r-o 15' DRIVEWAY EASEMENT ON LOT B CIG & SIDEWALK 'FORM V14�7%cr—tjo�4 W. n FOR A,B AND C TO FIRDALE AVE lN5Ft(; I IONS REQUIRED dA-We,&--ftq ED CD W GRADING CALCSI SECTION I, &L EXPOSE) SUR118 Z_— 6 A q AVG, CUT R E I CUBIC YA WITH SETBACKS ol — T J SECTID 11 20' AVG. CUT OF 3.5' CD Ljj CUBIC YARDS = 73.11 �SST�.DCZTqMl' U (y) TOTAL CUBIC YARDS 119.15 SCALE 1'=20' 14' 7h QL� CD jo3r 5' 27.5 "- CD LOT COVERAGE � Tax Account Par�l # 1 9.51 cu _j 3,810 SOFT. (47.1.) 2703-360-038-4400 --'�CTION 11 2L5' � ) z LOT AREA LOT SLOPE , DRAINAGE PLAN 14' 7.5' CD PROPOSED cl cu 8,059 SGFT. LESS THAN 5*/ ACCORDING TO RESIDENCE LJ CD SP 97-009 48.5' > cc) u FILTER ---\ :D �EEURE T. Z� . V _ SECTION I bj 14 GI IRE FARM 20' E.RL 14.5' _j SPO t LE FOR .CMKRJC:)NT OTOR IS RESSPO C.LI-EIERO 5' ION ONTROL A P4 NIAGE 14' 37' 0 22' 7.51 U 0% W LK 4gl H,7 6�104 AY ,IA p 7.5' PLACE E—L 1. EU L9 _ lRr— — . ..I. —� � r", I.RRII ­E I.E —IACI. F4� z Li cd a LL A-s 'E' DRIVEWAY -i < LL < u ul :2 > LL r'*-'X'- Dr.- NLL( FP'S DATUM 'PMNT �101)'ZS57 V A CB 65 NORTH OF PROPERTY LINE - 9. '1IRDALC z frowg 01-12 PAA) 15' DRIVEWAY EASEMENT ON LOT B -i C&.* fi9M*,*-fORM,-- FOR A,B AND C TO FIRDALE AVE, W. CL INSPECTIONS REQUIRED 4 Rf Janris Construction Technical Information Reporl Table of Contents i Project Overview 2. Conditions and Requirements Summary IJ 3. Off -Site Analysis 4. Retention/Detention Analysis and Design 5� Conveyance Systems Analysis and Design 6. Special Reports and Studies 7. Other Permits 8. Erosion/Sedimentation Control Design 9. Bond Quantities Worksheet, Retention/Detention Facility Summary Sheet, and Declaration of Covenant 10. Maintenance and Operations Manual List of Figures Figure 1 TIR Worksheet Figure 2 Site Location Z' 0 4 p 3 p 3 p 3 0, -40. 1" 0 Ci' p 3 b :J'cl p 4 c: Z: p 4 p 4 '0 0 p4 C p 4 p4 z Z' 2 1. Project Overview This project consists of three new SFR's and associated walk and driveways being built on three 8,000 s.f. lots created as a short plat in the late 90's. The plat concept is was for a detention pipe discharging to the Firdale drainage system. As the site underlain by a deep deposit of Everett soils, the new impervious is being infiltrated in accordance with the King County Design manual that states that all lots on outwash z soils shall be evaluated and if feasible infiltrated. The total proposed new impervious 0' is 10,871 s.f. for all three lots. A TIR Worksheet is attached as Figure 1 and a site 0 vicinity map is attached as Figure 2. M, con 2. Preliminary Conditions Summary The site is in the City of Edmonds and bounded by 1 001h Ave W and Firdale Ave W. 0 0 0 The site is underlain by Everett soils. 3: M M41 3. Off -Site Analysis C z All flows will be infiltrated. Any overflow of the system will flow in the same drainage path as it does now to the system along Firdale as originally proposed by the short M M plat.. ra, 0 In summary the off -site topographical and vegetative conditions suggest no unusual C: co drainage or erosion problems. M 0 z 4. Retention/DetentionMater Q uality Analysis and Design No off -site flows are coming on -site within the area of development. On site flows z are being infiltrated in infiltration trenches. The 98KCSWDM requires residential sites with less than 22,000 s.f. to be evaluated for infiltration. z three soil log holes and three infiltration tests. The 0 M The site was evaluated using tests showed the soils to be course sand and gravel draining much in excess of the maximum design rate of 20 in/hr. All holes drained within 5 minutes and could not actually be kept filled. No mottling or evidence of water was obs erved in any of the holes to 4' depth. The roof downspouts are going to infiltration trenches and the drive runoff is being sheet flowed to a saps rate catch basin and infiltration system for each lot. These a re shown on the attached site grading plans. 3 5. Conveyance Systems Analysis and Design The only conveyance is by 4" PVC as directed in the KCSWDM required downspout infiltration details. Z 6. Special Reports and Studies 0; No special reports are required. 7. Other Permits C M m ag No other permits are required. 0' 0 C:� XM: 10 8. Erosion/Sedimentation Control Design Sift fence had been provided on the design drawing downstream of any proposed -< 01 disturbance. The required construction entrance is shown on the plan. 0 0 C: 9. Bond Quantifies Worksheet, M 0: Z Facility Summaries, and Declaration of Covenant A Bond Quantifies Worksheet is not required for a small site Appendix C application. No covenant is required. Z: 10. Maintenance and Operations Manual 0 M Not required. 4 rr, LL "6 ME I, . . . . . . . . . . . is - I MIN- !, ma pp� King County Department of Development and,Environmental Services TECHNICAL INFORMATION REPORT (TIR) WORKSHEET P, k-', -pait,L1 PR -,T,:OWN&,ANb� ojEC -P PROJECTwLOCATI ION 1: IP" iENG34EERI--;.;��*�;.. oloct SMze,' Project Name ik, Address Location Township Z' Phone Range 0 :1 , &� ............. Section 2iU 0 R). Project Engineer Company-- M Address/Phone C a m 0 -a r D "P' ERM. Yr 0, C, . . . . . . . . .... Shoreline Management m Subdivison DFW HPA Short Subdivision COE 404 Rockery Grading DOE Dam Safety Structural Vaultb Commercial FEMA Ficiociplain Other *x-- -n 1:6) \0A Othei 9121;-P"2-k COE Wetlands m m 0 0 part. !f,r OMM BASI C: M 0 z community Drainage Basin z Part.6.�; sr-mcHARACTERISTICS:- Z lain River Floodplain 0, m Wetlands (SP r Seeps/Springs Critical Stream Reach High Groundwater Table ro Depressions/Swales Groundwater Recharge Lake Other Steep Slopes Sall Type. Slopes Erosion Potential Erosive Velcotles Addibonal Sheets Attached Z, 0 WIT CM) REFERENCE UMITATION/SITE CONSTRAINT inanm*s Ch. 4 — Downstream A I M— m C M -400 0 C m: ---------- in Z: > z Additional sheets Attached 0 mm MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS 0 0 Fn, DURING CONSTRUCTION AFTER PDNULUCTION C 0) tabilize Exposed Surface z (a 0 St KI onstruction Entrance Remove and Restore Temporary ESC Facilities Perimeter Runoff Control Clean and Remove Ail Slit and Debris Clean Gram, Restrictions ctices Ensure Operatio n of Permanent Facilities Flag m f SAO and open space z i: preservation areas Other z Other m P�11�'-- �&il 86RFACE-WATEKSY�§T Method of Analysis Grass Uned Infiltration Tank Channel Vault sion mp at at 00 Ins l0r'MItI9 Pipe System Energy Dissapator Flow Dispersal on of Eliminated Site open Channel Wetland Waiver Storage Dry Pond stream Regional Wet Pond Detention z 0 Brief Description of System Operation 0 M" Facility Related Site Urnitations 'n i! Reference Facility Urnitation m a 0 0 C, J r. m m: v, 7-R -Y S�M TSM CTS Pa 2 EA S[179ACTS:� C 2: Cast in Place Vault a Drain: - Easement re .9 Retaining Wall =ENA e t asement Acs.. E s 0 'n, Ro ckery > 4' High Native Growth Protection Easement t V. Growt P rot tic n x X, —Strmucdtural-on-SteeP-tSsllOPe---.--- rn m Other ter Other 0 Fn C M EN .4 �SIGNATURE.0FPROFESSIONAL GINEER- Paimas'. I It. ision have visited the site. Actual site I g t I or a civil engineer under my supervision my supery ants. Toth. best of ra into this worksheet and the attac hments. To the best of conditions as observed were incorporated s 0 s my knowledge the information provided here is accurate. z Z, signedlUate m NOTICE: IF THE DOCUMENT IN THIS FRAME IS LESS CLEAR THAN THIS NOTICE IT IS DUE TO THE QUALITY OF THE DOCUMENT. 110 W Ll VT, ; Ell 4�N NOTICE: IF THE DOCUMENT IN THIS FRAME IS LESS CLEAR THAN THIS NOTICE IT IS DUE TO THE QUALITY OF THE DOCUMENT. CD CD Ln GRADING CALCS 0.96 1 tw SECTIUN I Avc, CUT OF aw CUBIC YARDS = SWI CD < —J 1,D IRE IWIC AVG, CUT OF 3,5' WE -Ile W (y) #I: CUBIC YARDS - M-74 U r �/ DIR TOTAL CUBIC YARDS T13CK it fy- c) c <F r- CD (L ctj -J 7.5' 0 oj Ld CD- 0 1-- > OD u < ON LOT COVERAGE 33, SECTION 11 ry W 3,473 SQFI- C399> _j m W < LOT AREA PROPOSED :7 p p RESIMDE�N!ECE M 3 e,o-,t sQ-FT- 4v C-) T.. A—unt p:l co fu z 703-36o-m-450a CTION I Lall —SL"PE 1.4 po ZA LESS THAN 5% < 33' We fu 0 lz C) Lti 0i 3-4 ?9' A -i )SCALE 1'=20' <1 -q u fo DRAINAGE PLAN ACCORDING TO RIVEWAY I re SP 97-009 2 C.0 ca LD DWATIMM P +law 9 CD 13a, OF Pam-,RTY LIM < 0� 15' DRIV�WAY EASEMENT ON LOT B LD o— FOR A1,13 AND C TO FIRDALE AVE. W. IL am, -m—f ffl:,-7 NOTICE: IF THE DOCUMENT IN THIS FRAME is LESS CLEAR THAN THIS NOTICE IT IS DUE TO THE QUALITY OF THE DOCUMENT 360 07.4 C) c--) GRADING CALCS. SECTION 1, �3- c:) AVG. CUT 137 2' 46.G4 - SE]:BACKS :tt (y) CD CUBIC YAOS c:) pq SECTION 11, AVC, CUT OF 3.5' CUBIC YAR13S = 7331 C., 'it DEC 9 1 �,D (y) C) (y) :W- Lo TOTAL CUBIC YARDS - 119-15 SCALE 1'=POI 27.5 ry CD 1-- A LOT COVERAGE # I 9.v if 2t5' f) ()j —j Z703-3ro-M-4400 14' SFCTJON 7�5' z ca L(:T AREA LOT SLOPE � DRAINAGE PLAN ,FT. LESS TMAN 5Y ACCORDING TO Pq 01. OpOSED �0- RES113ENCE 0 — 1-- (u CD SP 97-009 ti 48.5' > Q ob SECTIEN I ly ME POM 1-- 14.5' '14' 5' E.1 37' El 0 c, 22, 7.5' P U 0 v LK AY 4(Y * ;K 7" El z pal :Em w A 0 7. J()u) ow Ljj I.r M- 0. M. Z C) 00 D w -j cu u Ea LU to :I- x CE L, DATUM PONT -100' c &;ntvy 0 PuE z < iz 15' DRIVEWAY EASEMENT ON LOT B L3 CL FOR AB AND C TO FIRDALE AVE, W. LL mm- =6 I,GRA41RG' SECTMH I AV& EuTir a, - dqz;c yAROS i- 66.74 SEMI!* Ava OF MOM YARDS M7 TOTAL CUBIC TARDS - IA LOT COVERAGE - 0,986 S%FT. (377) LOT AKA � 8,016sarl., C:,] C3 C) �oC) u ol 15' __1 CD _j �'D W (Y) C-) c) SCALE 1'=20' 1119T ry C:) C> T.x A..O—t PllMet # I TOCK P1 _J ?703-36v-030-430 CD LOT SLOPE 545' w oj Len T"AN 5'lVo4-e - Aill > co U 4- PROPOSED RESIDM 3V 34' W _j ",-SECqiM 1 , W, 'T %, z be 0( m ED X LL 2: 5.51 la, H 5.5 r ca SFCT�1'11N 11. A K y cm)—e < -37 LLJ VIL C) lAJ cu y u 7ol _j OA DA" PUNT _ ;A 0 Lo T_ 1 CAT(:" BASM DR GE PLA pi z CC R ING TO < < ENT ON LOT B 5' EWAY EASEM w ix _j DRIV SP C To V FOR A,B AND -C TO FiRIDALE AVE. W. Lj n 5.1.1 DOWNSPOUT INELTPATION SYSTEMS FIGURE S.I.I.A TYPICAL DOWNSPOUT UOUTRATION SYSTEM 7 /—roof drain PLAN VIEW 4- dgid or Wflexible NTS perforated pipe Z' O� ........................................... 0, M, ................................................. '-i -n infiltration trench suml i w/solld lid a rk 3 0 C) PLAN VIEW roof drain rn z NTS q overflow z e dgid or 6'ffe)dble splash block perforated pipe On hr—y* ... ..................... 6' MML ------------- --- hod k 5.0'min. 0 1 1/2"- ml C ca fine me h CB sump w/sofld lid K (W 0i 10' in varies L—*A fifterfabrio z acted backfill comp z V rigid or fle4ble perforated pipe 24" V washed rock av 12T" aa 1 1/2"-3/4" .�7 24. SECTION A NTS 911/98 1998 Surface Water Design Manual 5-7 SECT[ON 5.1 ROOF DOWNSPOUT CONTROLS FIGURE 5.1.1-B ALTERNATIVE DOWNSPOUT INFILTRATION SYSTEM FOR COARSE SAND AND GRAVEL from roof Z' 011 P grass 6. min Overflow Oi R'4i 111Y-310 NOTE: Same length dimensions 0 C, M rn� Washed rock 18'm1n and site limitations as typical -system 16 tg LZ I Tmin min -X-SECTION-- im M NTS 0 Fn C R A q v zx� 1998 Surface Water Design Manual 9/1/98 -' ;,zZ e) 14% Z;; ck, i 7 77 EPA OKA M AA M:, m 00 On, mm c K CA PH 'Zo e, kt, 0:n LILI 0 ifi T p -d -q fo tr XC�.l 3W3S ul (n 33 :x 5.1.1 DO"SPOTJT INFILTRATION SYSTEMS E14EMTRATION SYSTEMS 5.1.1 DOWNSPOUT Downspout infiltration s3ulems are trench systems intended only for use in infiltrating runoff from roof downspout drains. They are not designed to directly infiltrate surface water that could transport sediment or pollutants, such as from paved areas. 0 BASIC REQUIREMENTS 1. Single family subdivision projects subject to Core Requirement #3 must provide for individual downspout infiltration systems on all lots smaller than 22,000 square feet if feasible. 2. The feasibility or applicability of downspout infiltration must be evaluated for all subdivision single family lots smaller than 22,000 square feet. The evaluation procedure detailed below shall be used to determine if downspout infiltration is feasible or whether downspout dispersion can be used in lieu of infiltration. This procedure shall also be used to evaluate all projects proposing to apply roof downspout controls as flow control BMPs per Section 5.2. 3. For subdivision single family lots greater than or equal to 22,000 square feet, downspout infiltration is infiltration optional, and the evaluation procedure detailed below is only required if downspout is being proposed voluntarily. Note: 1fdownspout infiltration is not required orprovided on these lots, then a downspout dispersion system must be provided per Section 5.1.2 (p. 5-9). C3 PROCEDURE FOR EVALUAIING FEASIBILITY 1. A soils report must be prepared by a geotechnical engineer. The report must reference a sufficient number of soils logs to establish the type and limits of soils on the project site. The report should at a minimum identify the limits of any outwash type soils (i.e., those meeting USDA soil texture classes ranging from coarse sand and cobbles to medium sand) versus other soil types. 2. On lots or sites with no outwash type soils, a downspout dispersion system per Section 5.1.2 ----�---��-----(p.--5z9)-may-be-used-iTr-lieu-af-infiltration�-If-downspout-irifiltration-is�still-desired-to-qualify-for-flo.w—, control sizing credits, it must be shown to be feasible as described below. ting al site -specific its 3. On lots or sites containing outwash type soils (coarse to medium sand), addition must be done. Individual lot or site tests shall consist of at least one soils log, a rninimum of 4 feet in o and the USDA textural class of the depth (from proposed grade), identifying the SCS series of the s il soil horizon through the depth of the log, and noting any evidence of high groundwater level, such as ltration is being mottling. Note: This testing is also required on lots or sites where downspout i . nfl proposed in soils other than outwash. 4. If site -specific tests indicate less than 3 feet of permeable soil to the seasonal high groundwater table, then a downspout dispersion system per Section 5.1.2 may be used in lieu of infiltration. If downspout infiltration is still desired to qualify for flow control sizing credits, the minimum 3-foot depth to groundwater may be met by using fill material as allowed in the design criteria below. 5. On lots or sites with more than 3 feet of permeable soil to the seasonal high groundwater table, downspout infiltration is considered feasible and mandatory if the soils are outwash type soils and the infiltration trench can be designed to meet the minimum design criteria specified below. Voluntary provision of downspout infiltration must also meet these design criteria in order to be approved as feasible. [3 DESIGN CRITERIA -7) shows a typical downspout infiltration system, and Figure 5. 1 J.11 (p. 5-8) Figure 5. LLA (p. 5 presents an alternative infiltration system for sites with coarse sand and cobble soils. These systems shall be designed as specified below. 9/l/98 1998 Surface Water Design Manual 5.5 Z� —4 -fi SR in C M 0 O� m fu 0 -n n -4 X m In 0 0 C (a = 0 In 0 Z to Z 0 1 0 SEC11ON5.1 ROOF DOWNSPOUT CONTROLS General 't nimum lengths (linear feet) per 1,000 1. Downspout infiltration trenches shall be the following mi I square feet of roof area based on soil type: Coarse sands and cobbles: 20 LF Medium sand* 30 LF Fine sand, loamy sand 75 LF Sandyloarn 125 LF Loam 190 LF 2. Ma)dmum length of trench shall not exceed 100 feet from the inlet sump. 3. Minimum spacing between trench center lines shall be 6 feet. 4. Filter fabric shall be placed over the drain rock prior to backfilling. th 5. Infiltration trenches may be placed in fill material if e fill is placed and compacted under the rate is at least 8 inches per supervision of a geotechnical engineer, and if the measured infiltration hour. Trench length in fill shall be 60 linear feet per 1,000 square feet of roof area. Infiltration rates shall be tested using the methods described in Section 5.4.1 (p. 5-53). 6. Infiltration trenches are not allowed on slopes steeper than 25% (4:1). A geotechnical analysis and p slope or report may be required on slopes over 15% or if located A#in 200 feet of the top of stee landslide hazard area. yard drain or catch basin with grate cover is 7. Trenches may be located under pavement if a small placed at the end of the trench pipe such that overflow would occur out of the catch basin at an ement, and in a location which can accornmodate the elevation at least one foot below that of the pav ti overflow without creating a significant adverse impact per Core Requirement #1 (see See onl.2.1). f system failure. _bt"t��qLth��pjvTent �ubgT4!L. th�evenl of Setbacks or sensitive area (except steep i. An trenches must be at least 5 feet from any structure, property line slopes). 2. All trenches must be at least 50 feet from any sensitive area steep slope. This setback may be reduced to 15 feet based on a geritechnical evaluation, but in no instances may it be less than the buffer width. 3. For sites with septic systems, infiltration trenches must be downgradient of the drainfield. Ibis requirement may be waived if site topography clearly prohibits subsurface flows from intersecting the drainfield. Documentation Requirements 1. The approved plans for single family subdivision projects must show infiltration trench details and the approximate location and size of each proposed downspout infiltration system and septic system (if applicable). Alternatively, details of representative lots may be provided to depict approximate locations of downspout infiltration systems and septic systems (if applicable). 2. If the proposed project is a subdivision, the following note conditioning single family residential recorded with the plat building permits on compliance with the approved infiltration systems shall be or short plat: "Single fainily residences constructed on lots created by this subdivision must provide downspout infiltration systems according to the details shown on the approved plans." 1998 Surface Water Design Manual 9/1/98 5-6 Z'L C: rn M2 4: 0 -n n m m 0 0 C V) M 0 Z r- :q �, M Z Z ru f FINAL PROJECT APPROVAL FORM TO: DATE: MEMO TO: PERMIT COORDINATOR, BUILDING DIVISION FROM: FIRE DEPARTMENT DATE — ENGINEERING DIVISION DATE LS1 PLANNING DIVISION DATE— PROJECT — SITE ADDRESS---'Ic�: PERMIT #_U2QLa2,&�a_ADB#_____--PATE INSPECTED DESCRIPTION OF WORK TO BE INSPECTED---e�;�..�� A field inspection was conducted to determine final compliance with approved plans. Final approval denotes that there are no objections from the above signed Department to the release of PERFORMANCE BQNDS and the granting of ---X-GRANT FINAL PROJECT APPROVAL GRANT PROJECT APPROVAL WITH CONDITIONS NOTED cl Copy of CONDITIONS given to owner/contractor by inspector FAILED FINAL INSPECTION - OUTSTANDING ISSUES u Copy of CORRECTION NOTICE given to owner/contractor by inspector 2. 3. RE_INSpECTED OUTSTANDING ISSUES GRANT FINAL PROJECT APPROVAL Date— Sign_ ocaprvl.doc.]:temp;bldg;fonnsIO/OI z 0 :;9i C M MO 0 C -4 M = M M Z ,0 --1 C Cn 0 -n M M 0 0 0 M C 0) C U) M C) Z z U) z M FOUNDATION: Footing .......... I .......... Wall .......................... Pier/Porch z 0 Retaining Wall ........... 0 ITI Slab Insulation .......... PLUMBING: --I 3: Underground ME M C M Rough -In ............ Commercial Final -j ITI HEATING: Gas Test ............ ? -d5 Gas Piping ................. on Equipment Commercial Final 3: M ITI EXTERIOR SHEATHING IT NAILING .......................... C ('0 FRAMING ..................... FIRST FLOOR FRAMING M C), INSULATION ............. Floor Insulation z Wall Insulation ........... CD Ceiling Insulation z SHEETROCK NAILING IT! SPECIAL INSPECTION MISCELLANEOUS .......... FINAL APPROVAL FOR OCCUPANCY . ............. Sidesewerfl- AmoutPold RCCC, $ Date Water MeL-rSiz'e"_" Amount Paid Receipt #_ DatePurchased Mount Paid $_LjLt=jPt 2 T-'Z!e