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HomeMy WebLinkAbout03197 - Technical Information Report - Drainage �� Core Design,Inc. CORE 14711 N E.29th Place SuiFe #101 Bellewe, Washington 98007 \ �DESIGN 425.885.7877 Fax 425.885.7963 `/ STORM DRAINAGE ANALYSIS FOR � PHASE 2 STOR-HOUSE SELF STORAGE I I RENTON, WASHINGTON � �'�f .��' j G.r` .. .o /� / t �\�G � 33251�� /,.��� �����`��� ��jb� ��NAL E�;�,'�,./I Approved by: Robert H. Stevens, P.E. �� Date: August, 2004 ;�REs �2-04- �� Core No.: 99121 R E C E�I�-�V E�D ���1G 2 � ���4 �`r`T����'S�`�V!CE � rc����-{- � �(�� � �JL/�Q(���o ENGINEERING PLANNING � SURVEYING 3 �� 7 RENTON MINI STORAGE TABLE OF CONTENTS , 1. Project Overview 4. Conveyance System Analysis and Design �, 5. Erosion/Sedimentation Analysis and Design I 1. PROJECT OVERVIEVV: Phase 2 of the Stor-House Self Storage is located on the southwest corner of the Stor- House Self 5torage and Office Park. The site plan and type of buildings for Phase 2 will be consistent with the Phase 1 portion of the Stor-House Self Storage project. I The initial improvements for the original design considered future improvements for the i , area of Phase 2. The total property is 7.77 acres. T'he west 50 feet was intended to continue to slope to the west. The remaining area, 7.0 acres, was intended to slope to the detention/infiltration facility. The design for phase 2 will not exceed the area originally designed to go to the drainage system. Phase 2 improvements are intended to only come within 55 feet of the west property line, 5 feet short of what was considered in the original parameters. Since the detention system was sized for the ultimate build-out of Phase 2, this report will not reanalyze the detention facility or downstream. Please refer to the Appendix far the original design of the detention faciliry. The only aspects of the new Phase 2 design that will need analysis are the conveyance system and erosion control. 4. CONVEYANCE SYSTEM ANALYSIS AND DESIGN: 'The conveyance system for the site was designed for both the 25-year, 24-hour storm and the 100-year, 24-hour storm. A conveyance sheet was generated for the 25-year and 100- year storms using the rational method to calculate flows for each area collected by each catch basin. The precipitation rates for the 25-year, 24-h��ur �t��rn� and thc 10(1-ti-�ar, 24- hour storm are 3.40 inches and 3.90 inches consecutivelv. The flows generated from the 25-year, 24-hour and 100-year, 2-�-hour ,t��nn� �ti ere input into a backwater analysis spreadsheet to confirm adequate sizin`�. A weighted C value was used for each area collected by each catch basin. The samr weighted C value from the original design was used. The averaQe C value for the ����r��l I developed site is (0.6 AC*0.25 + 6.4 AC*0.90)/7.0 AC =0.84. The original conveyance analysis was used to determine tailwat��� elz��ati�►i� ��t ii�,� n�•�� CB 5. However it was apparent that the basins have changed from the original assumptions for the basins of Phase 1, CB 18 and 19. The revised analysis gavc �:� .� tailwater elevation at CB 19 (phase 1, CB 5 phase 2) of 311.01 for the 25-year eve� �:� ' 312.25 forthe 10� . . ,,f T�,;_ r�.;��,� �r, . .,� ,,. ,� � ., ,_ .�., � ,�,., h�,r�. �-rz i . � to be conservativc The backwater analysi� was pc;riormed to ensure that durin� the 2�-year design storm, tl�� malcimum water surface elevation in each structure did not exceed an elevation equal to 0.5' below the rim and during the 100-year design storm, the malcimum water surface elevation did not cause flooding of structures. Exceedance of a rim would be allowed if the topography of the basin would allow the vverflow to be conveyed to the next _. downstream catch basin or if the topography could ensure that ponding would not cause structural damage. - During the 25-year, the headwater elevations did not exceed 0.5' less the rim. During the 100-yeaz, the headwater elevation exceeded the rims in CB 2, CB 3, CB 6 and CB 7. The overflow from these catch basins will pond within the roadway and will not flood any adjacent buildings. - - - - - - - - - - --.�- -�- - - - - , NW 1/4, lVW 1/4, SEC. 16, TWP. 23 N., RGE. 5 E., W.M. � � __ CB 2 CB 3 CB 4 TYPE l TYPE l R/M 312.12 RlM ,312.17 �E l 12"lE .309..35 12"lE ,309.79 RlM ,312.89 12"lE 310.49 SD , �B � 0,19 0.23 0.39 TYPE l � � RlM .3>2.4.3 0.16 12"iE ,�09 0,� �2¢� covFR) 0.14 0.17 0.27 SD SD CPB�5 CB 6 CB 7 CB 8 TYPE l TYPE l RlM 311.72 R/M ,312.12 RlM .312.17 T1'PE l 12"/E ,309.42 12"lE 309.7,3 12"lE .3f0.17 R/M ,312.89 (�..�' cou�R� (i.4' cov�R) (�' cov�R) ��'iE 3�0.8� (�' cov£R) CS TORM D RA lNA GE EXH/Bl T � STOR-HOUSE SELF STORAGE � � i � Ro �—, � � c S C A LE 1 " = 40' � 1560-1401H A VE. NE, SUITE 100 � BELLEVI/E WA 98005 • �O� 1471INE29thPlace,N�O� DATE 0 5/0 8/0 3 S H E E T O F Bellevue,Waehingeon 98007 O 20 4,0 80 425.885.7877 Fax 415.085.7963 �DESIGN DESIGNED RHS 1 1 ENGINEERING � PLANNING • SURVEYING DRAWN ✓EH PROJECT NUMBER 99121 _ __ ,i � 4 iN HF, I STORM CONVEYANCE SYSTEM D�SIGN �.��AT��N: K�N�:COUNTY 24-HR RAINPALL: 3. C S OI3 NAMP:: Pht�sc 2 Stor-Huuse ticJf ti�ur:igr JnR NiI'V1RF.R: 99121 PREPARED f31': R.Stcvens DI',SI(;N STORM: 25 YEAR . . . � TNCRF.MfiNTAI; � �RIINqF'F . 6NPP:kVipliti �� � �.'1'IMh'UP � RAINPALL 'PRl[tU1ARY .. � .1'IPIC Pll'P'� P1PN:���. ..,dL"I'UAL� 'PNAVk:I. � p�Pl.(;A1�,a1�:����Y5�11V1b1r'�1t�' PIPN:wP;GA1k:N'I' . AHH;A,,. .(407sF1�ICYliN7'� AAliA. .. ..SUM(lN (',OtY(... ..TNTRN91'1'�-. ..FI,OW MANNIN(i:S. UTAMKIP;R SI.UPIi LINGTII VBLVCI'1't' 'PIMHi l)(F4II.I,) Vli�'OLI,1 VIACTI/QrI�L'LL1 FROM TO {AC;NN;ti) � "t., IA*.C}� �(A�".l 1 (MINUTGS)... �UNIt#R� ICF91 �'�'n' .�.ON(`�1k:5) �{PP;RCM.N'1') (PN,1.1'1� U'IY3b;CJ� fMIN1��71'sEl.. .(CC'S'1 IP1Y5F.C� IPt;Rf.F.Y1')�. x 7 0270 0.84 0.227 0.227 10.00 2.U2 U.aSy 0.012 12 0.500 140 2.52 O.y3 2.7"�v 3.a7 I(i.8%c 7 6 0.170 0.84 0.143 03�0 1.0.93 1.91 0.706 OAl2 12 0.500 87 2.85 0.51 2.729 3.47 25.9�70 6 5 0.I40 0.84 0.118 U.487 11.44 1$6 0.904 0.012 l2 0.500 63 3.08 034 2.729 3.47 33.I°lo 5 ex 0.160 0.84 0.134 0.622 11.78 1.82 1.132 0.012 l2 0.500 12 3.27 U.06 2J29 3.47 41..5% 4 3 0390 0.84 0328 0.328 10.00 2.02 0.663 0.012 12 U.SUO 140 2.85 0.82 2.729 3.47 24.3% 3 2 0.230 0.84 0.193 0.521 10.82 1.92 1.002 0.012 12 0.500 87 3.18 0.46 2J29 3.47 36.7%n 2 1 0.190 0.84 0.160 0.G80 11.27 1.8'7 1.274 0.012 12 0.500 fi3 3.41 0.31 2.729 3.47 46J% 8/17/04 Core Design, Inc. PAGE 1 ' STORM CONVEYANCE SYSTEM DESICTN LOCATION: KiNG COUNTY 24-HR RAINFALL: 3.9 iNCHES TnR NA�1F.: I'has�e 2 SLur-Huuse tielf S�ur�Kr JOB NU�1R1?R: Y9121 PRH;PAR!?U IIY: R.Stevcns llESIGN S'I'URM: 100 YP�AR . . INt;RHMP:ry"CAI. . RIfNpP'Y IMPY'RVIf,IUti � �.TIM14FUP'� � �RA[NTA1,L 9BBDTAIiY � PIPE .PfPP�� PIFE� ACTliAL. �' TRAVSSL � .:�Ip���,l�lY.4CT7'�'.5'�����1K�' PIPNISh',GM111<Mf ANF;A.. COIN'F7C1N;N1' ARL',A.. SOb1UP'... �.CONC.... �1NTF:Nti17'1' I1.OW ���MANNIN(i'$� I)IAM$CY;R �'�6LOPP.. I,Ii.NfiTH V4:LqC1Y'Y -....7lYfE ��Q(FUI;L1. .V(FOI.LI (7(A(:l'1!Q(PULI.) N'ROnt 'fb IACNKti).. .'i.^ � (A�"(:) ��(A"'<") �,.(M(NIGTN:S?. . ..ilN/Hti) ((;.k"ti) .. ��"i," QNCIiF.c'1 (PF.RCFNT) p�13ET) (NT/SPC7� ���tMINU'FFSI ���(CfS). (FTlSF.C� (PF.RCF.NT) 8 0.?%U U.24d 0.22'7 U.227 IU.UO .'.�i9 US41 U.012 12 D.50p Id0 2.62 0.89 2.729 3.d7 19.R`�� 7 6 0.170 0.84 0.143 0.370 t0.R9 2.26 O.R36 0.012 12 0.500 87 3.02 0.48 2.729 3.47 30.6�/� 6 5 0.140 0.84 0.118 0.487 11.37 2.2U 1.072 U.U12 12 Q500 63 3.23 0.32 2.729 3.47 39390 5 ex 0.160 0.84 0.134 0.622 11.69 2.16 1344 0.012 12 U.500 12 3.44 0.06 2.729 3.47 49.2�/0 4 3 0.390 0.84 0.32R 032R 10.00 2.39 0.782 0.012 12 0.500 140 2.97 OJ9 2.729 3.47 28.G%n 3 2 0.230 0.84 0.193 0.521 10.79 2.28 1.185 0.012 12 0.500 87 3.32 0.44 2.729 3.47 43.4�/, 2 1 0.190 0.84 0.160 0.680 11.22 2.22 1.510 0.012 12 0.500 63 3.54 030 2J29 3.47 5539, 8/17/04 Core Design, Inc. PAGE 1 RACKWATER CALCULATIONS OD NAME: Phase 2 Stm•House Self SMrage YItENAkEU RY: R.5'f�VENS I OQ NUMRER: 99121 llE51GN STOIiM: 25 YEAR ENTRANCE ENTRANCE EXIT O[ITLET [NLET APPROACH 6END JUNCT►ON PQ'E PIPE MANNING'S OUTLET INLET PIPE FLOW VELOCITY TAILWATER FRiCTiON HGL HF.AD HHAD CONTROL CONTROL VELOCITY HF.AD HF.AD HEAAWATER FROM TO FLOW I.ENC:TH DIA. n F.1.F.VATION ELEVATION ARF,A VELOCI'fY HEAU ELEVATION LOSS ELEVATION LOSS LOSS ELEVATION ELEVATION HEAD LOSS LOSS ELEVATION CI1 CA (CFS) (FF,F.T) (IN VALLiE FF,ET FEET 5 N"C FT/SEC F'6�;'I FEET) FEET (FEET) (FEET) (FEET) (FEET) (FEET) (FEET (FEET) (FEET (FEET) RIM EL 2 1 13 G3 12 0.012 309A3 3093g Q79 1.62 0,04 311.01 0.0'7 311.08 0.01 0.04 311.13 0.00 0.03 0.00 0.00 311.10 312.12 3 2 1.0 87 12 0.012 30935 30999 0.79 1.2R 0,03 311.10 0.06 311.16 0.01 0.03 311J9 0.00 0.01 0.00 O.pO 311.18 312.17 4 3 07 14U 12 U.012 309.79 310.49 0.79 0.84 0.0I 311.iR 0.04 311.49 0.00 0.01 31L50 0.00 0.00 0.00 0.00 311.50 312.A9 R 5 0.9 63 12 0.012 309.42 309.'73 0.79 I.15 U.02 311A1 UA3 311.04 U.UU QU2 311.07 0.00 OA1 0.00 0.00 311.06 312.12 ') (, U,7 87 12 4U12 3Uy.7i 710.17 0J9 U90 0.q1 31L06 0.03 311.17 0.00 0.01 311.19 0.00 0.01 0.00 090 3ll.18 312.17 8 7 0.5 14U 12 Q012 310.17 310.87 0.79 0.58 0,01 31L18 0.02 311.ft7 0.00 0.01 '�Il.RB 0.00 0.00 0.00 0.�)0 311.RR 312.R9 A/17/04 PAGE t DACKWATER CALCULATIONS 106 NAh1E: Phsse 2 SlurHuu+e Self Storage PREPARED BY: R.STEVENS I OB NUMBER: 9YI21 DESIGN STORM: t00 YEAR F.NTRANCF. ENTRANCF. EXIT OUTLF.T INLF.T APPROACH DEND JUNCTION PIPF. PIPF. MANNINC'S p[fTI.F.T INI,F,T PIPF, FLOW VELOCITY TAII.WATER FRICTION HGL HEAD HEAD CONTROL CONTROL VF,I,OCiTY HF.AD HF.AD HF.ADWATER FRUM TU FLUW LENGTH DIA. n ELEVATION ELEVATION AREA VELOCITY HEAD ELEVATION LOSS ELEVATION LOSS WSS ELEVAT[ON ELEVATION HEAD LOSS LOSS ELEVATIUN CB CB CFS (FEET IN VALUE FEET FEET S FT T/SEC FEET FEET FEET (FEET FEET) FEET) (FEET) FEET) (FEET (FEET (FEET FEET RIM EL 2 1 1.5 63 12 0.012 309.03 30935 0.79 1.92 0.06 312.25 0.10 31:35 0.01 0.06 312.41 0.00 0.04 0.00 0.00 312.78 312.12 3 ? 1.2 87 12 0.012 30935 309.79 OJ9 1.51 0.04 3123R O.OA 312.46 Q�I 0.04 312.50 OAO 0.02 0.00 0.00 312.49 312.17 4 3 O.N 140 12 0.1112 30I.7J 310.4) OJ9 1.(IU O.U2 312.49 UA6 i12.54 0.00 OA2 312.56 0.00 0.00 Q00 0.00 312.56 312.89 6 5 1.1 63 l2 OAl2 3U9.42 309.73 Q79 136 0.03 3I225 0.05 312.30 0.01 0.03 31233 0.00 0.02 0.00 0.00 3I232 312.12 7 6 O.R 87 12 0.012 309.73 310.17 0.79 L06 0.02 312.32 0.04 31236 0.00 0.02 31238 0.00 0.01 0.00 0.00 312.37 312.17 R 7 0.5 �40 12 0.012 31U.17 310.R7 0.79 O.fi9 0.01 31237 U.U3 312AU QOD U.U] 312A1 QUO 0.U0 U.00 O.pU 312.41 312.89 8/17/04 PAGE 1 REVISED PHASE 1 CALCULATIONS � � ���� 4 ,� _ � ' �--, � � ! i ?_ ; �� � , ! �- � ; , � -, � I � L -! i-� � � �_ r- ; i � �_, fr- !� � ; � ;--; ; ,_ STORM CONVEYANCE SYSTEM DESIGN ' ���AT,�N: K,N����NTY 24-HR RAINFALL: 3.4 INCHES )OR NAME: AcFis Sclf Stm•age and Officc JnK NU�1RI?R: 99121 PRP;PARF.D BY: R.Steven,c' DESI(;N STORM: 25 YRAR � � INCRN;MEN1'Al.. RIINII4'F'. .��(MPP:kV11:lUti �7'IMF:OF KA{NNAI.L 'fHINIPPANY . . � �PIPI? �PIPP:� PIPI+. AC'fllAl, 'f'RAVB:I.'.. . PIPF CAP����{TY!fI�IMARY MPRSI?GMF.N'P ARF:A COBF'6'ICIRN`C ARGA AOTi(1F �CONC. INTTSNSt79' 1'LON � AiANNINi:$ �DIA1v1iS'fl?IL� SLOPF'� LLNfiTlfi �VI?LOCITY TIMP Q(Fl��.l.) �V(FIII.I.) (J(AQ7')/Q(P'UI.1.) FRUM 7'6 lACk&11 ^(." . tA`(J � (A'"ll (MINVI'Pi3) IIN/fll21 �..� (l;P'�) �. �"u" .. qNCNP;tiI ��IPF:RfI?N'1')� (N'4:b.7`J'� (4'fl!iN;(:t. [MINiI'Ph:ti) (f'M5) (1"CISP:CI. �(PM:KCF.N'1) I1 10 0.200 0.84 O.163 0.1(i�3 10.00 2.02 0340 0.012 12 0.�00 186 2.40 1.39 2.9'JO 3.�31 1L4�• 10 ) 0.400 Q84 0336 0.504 11.29 1.87 0943 OAl2 12 0.500 106 3.13 O.g6 2J29 3.47 34.5%� 9 S 0300 0.84 0.?52 0.756 11.86 1.81 1370 OAl2 12 0.500 100 3.47 0.48 2.729 3.47 50.2°!0 8 7 0.200 0.84 0.168 0.924 1234 1.77 1.632 0.012 12 0.500 100 3.61 0.46 2.729 3.47 59.8% 7 6 0300 0.84 0.252 1.848 12.80 1.72 3.187 0.012 12 0.500 60 3.47 0.29 2.729 3.47 116.8% 6 5 0.000 0.84 0.000 5.040 13.09 1.70 8.568 0.012 18 0.500 56 5.15 0.18 8.047 4.55 106.5% 5 4 0.600 0.84 0.504 5.544 13.27 1.68 9341 0.012 1R 0.500 160 4.55 0..59 8.047 4.55 116.1% 4 4a 0.700 0.84 0.588 6.132 13.8g 1,64 10.045 0.012 18 0.500 94 4._5g U.34 8.047 4.55 124.8�/� 14 13 0300 0.84 0.252 0.252 10.00 2.02 0.510 0.012 12 0.600 189 2.76 1.14 2.990 3.81 17.1% 13 12 0300 0.84 0.252 0.504 11.14 1.R9 0.951 0.012 12 0.600 103 331 0.52 2.990 3.R1 31.R% 12 7 0.200 0.84 OJ6R 0.672 11.66 1.83 1.231 0.012 l2 0.600 143 3.SR 0.67 2.990 3.81 41.2`70 I8 17 0.200 0.84 0.168 0.168 10.00 2.02 Q340 0.012 12 0.700 127 2.59 0.82 3.229 4.11 10.5�7� 17 16 0.200 O.R4 0.168 0.336 10.82 1.92 0.646 0.012 12 OJ00 52 3.19 U.32 3.229 4,11 20.U°/n 16 15 0.100 0.84 0.084 1.722 11.14 L89 3.250 0.012 12 0.700 9S 4.h9 034 3.229 4.11 100.6% 15 6 0.200 0.84 0.168 3.192 11.4R I.85 5.909 0.012 15 1.000 85 6.39 0.22 6.99R 5.70 84.4�70 19 15 1.550 0.84 1302 1.302 10.00 2.02 2.636 OAl2 12 0.600 122 4.30 0.47 2.990 3.81 88.2% 3 2 0.100 0.84 0.084 0,084 10.W 2.02 0.170 0.012 12 0.600 59 1.92 0.51 2.990 3.81 5.7% 2 1 0.4(H1 O.R4 0.336 0.420 10.51 1.96 0.823 0.012 12 0.600 140 3.20 0.73 2.990 3.81 27.5% 1 vlt U.600 0.84 0.504 0.924 11.24 1.88 1.734 0.012 12 3.000 9 6.98 0.02 6.685 t3.51 25.9% 8/17/04 Core Design,Inc. PAGE 1 �.�TORM CONVEYANCE SYSTEM DES�I:Y'N LOCATION: KING COUNTY 24-HR RAiNFALL: 3.9 INCHES ►Oft NAM1IE: Ac�is Self Stora�e and Otlicc J�)lt NU1iBI�:R: vvl?1 PRI�:PARF.D Rti': R.Stevens DESIGN S'I'ORh4: 1011 Y(?AR �. INCRh:Yil'sNTAL.� RUNOFF'.. �� I!NI'F,RWQliS�'.'� � 7'IMF�UF... �RAINF'AI;L� �TR161PCARY. . �� . .PIPE �PIPI:.�.. � PIP1i �... AC'I'UAL TkAVEI �'����I�I?C;AP��CITY SIIMMARY� �� PIVI:SEGMEN7' ARPA COEEFICILNT. ��ARFA SC�h111Y�� {'lIN('�. �� 1N7'NNtilll� 4'f.OW �1ANNIN(YF UTAMF,T'ER SI�,�P� .L2NG'CIS VGLOC77'S' 17ME� Q(h'Iii,l.) V�MY)I.1.) 4)(AC'I'Nl,)(N111.1.) 4'ROM 'i0 (ACNEti) ��^("' IA"C) IA'C) (MINOTP;S) l7N/JIRI [CF'9). "n" (IVCNN'.ti1 fPMRCM:N'I')� 11'�'1'':F';'P1 ll'178LS1') (MINU'f1i51 (CP'S) 0'CItiItiCI l�£Rf,EY'P) II 10 0100 0.84 0.168 U.li,B IO.UU ?:4�) O.A01 0.012 12 0.�00 186 ZSl 1.2? 2.99(1 3.t;1 13.-1°�-,'- 10 9 0.400 0.84 0336 O.Sp4 11.22 2.22 1.118 0.012 12 0.500 106 3.27 0.54 2J29 3.47 41.0% 9 8 0300 0.84 0.252 0.756 11.7� 2.15 1.62R 0.012 12 0.500 100 3.61 0.46 2.729 3.47 59.7%n R 7 0.200 0.84 0.168 0.924 12.23 2.10 1.943 O.OI2 12 0.500 100 3.75 0.44 2.729 3.47 71.2% 7 6 0300 0.84 0.252 1.R4R 12.6� 2.06 3.799 0.012 12 0.500 60 3.47 0.29 2.729 3.47 139.2% 6 5 0.000 O.R4 0.000 5.040 12.96 2.03 10.215 OAl2 18 0.500 56 4,55 0.20 A.047 4.55 126.9% 5 4 0.600 0.84 0.904 5,544 13.16 2.01 11.126 OAl2 ]A 0.500 160 4.55 0.59 8.047 4.$$ 1383%, 4 4t� 0.700 0.84 0.588 6.132 13.75 1.95 11.973 0.012 18 0.500 94 4.5$ 0.34 R.047 4.55 148.8% 14 13 0300 0.84 0.252 0.252 10.00 2.39 0.601 0.012 12 0.(00 189 295 1.07 2.990 3.81 20.1% 13 12 0300 0.84 0.252 0.504 11.07 2.24 1.128 0.012 12 U.60U 103 3.48 0.49 2.990 3.R1 37.7% 12 7 0.200 0.84 0.168 0.672 11.56 2.18 1.464 OAl2 12 0.600 143 3J7 0.63 2.990 3.81 49.0% 18 17 0.200 0.84 0.168 0.168 10.00 2.39 0.401 OAl2 12 0.700 127 2.73 0.77 3.229 4.11 12.4% 17 16 0.200 O.R4 0.16R 0336 10.77 2.28 0.765 0.012 12 0.700 62 3,29 0.31 3.229 4.I1 23.7�/ 16 15 0.100 0.84 0.084 1.722 11.09 2.24 3.850 0.012 12 0.700 9$ 4.11 0.39 3.229 4.11 119.2% 15 6 0.200 0.84 016R 3.192 11.47 2.19 6.985 0.012 15 1.000 85 6.50 0.22 5.998 SJU 99�8% 19 15 1.550 0.84 1302 1302 ]0.00 2.39 3.107 0.012 12 0.600 122 4.34 0.47 2.990 3.81 103.9% 3 2 0.100 0.84 0.084 0.084 10.00 2.39 0.200 0.012 12 0.600 59 2.06 0.48 2.990 3.81 6.7% 2 1 0.400 O.R4 0.336 0.420 10.48 232 0.9�3 0.012 12 0.600 L40 337 0.69 2.990 3.81 32.5% I vlt 0.600 0.84 0.504 0.924 11.17 2.23 2.056 O.U12 12 3.000 9 7.41 0.02 6.6RS R.S1 30.8% 8/17/04 ---� PAGE 1 BACK W A'LF.R CAI,COi.ATION5 IOH NAMF:: Aegis Self Storuge and Oflice,revised PREPARED BY: R.STHVENti I OR NUMAER: 99121 DESIGN STURM: 25 YEAR ENTRANCF. ENTRANCE EXIT OUTLET INLET APPROACH BENll JUNCTION P�E PIPE MANNING'S OUTI.ET INI.ET PIPE FLOW VELOCITY TAILWATER FRICTION HGL HEAb HF.AD CONTROL CONTROL VELOCITY HEAD HEAD HEADWATF.R FROM TO FLOW LENGT[I DIA, n ELEVATION ELEVAI'ION AREA VF.LOCITY HF.AD F,LF.VATION LOSS ELEVATION LOSS LO55 ELEVATION ELF.VA7'fON HF,AD LOSS LOSS ELEVATION CB CB (CFS) (H'F.ET) (IN) VALUE (FEET) (REET) S FT FT/SEC E'E�;'1') (FF.ET) (FEET) (FEET) (FEET) (FEET) (FEET) (FEET FEF,T) (FF.ET) (FEET) (FGGT) RIM EL 1 vit 17 '� 1. 0.012 307.50 307.77 0.79 2.21 QOS 3U9.UU 0.02 309.02 0.02 O.OR 309.11 0.00 OA2 U.UU ii,fi0 309.09 312 2 l 0.8 140 12 UA12 3U7.77 30R.67 0.79 LOS Q.02 309.09 0.06 309.61 UAU QU2 3G1.63 0.00 0.00 0.00 O.UO 30y,G3 312.9 3 2 U2 59 I2 p.012 30R.61 30R.96 099 022 0.00 309.63 0.00 309.94 0.00 0.00 309.96 0.00 0.00 O.OU 0.00 3099fi 312.5 19 15 2.6 122 12 0.012 ?07.70 308.47 UJ9 3.36 O.1R 310.24 0.56 310.80 0.04 0.18 ?11.01 11.1111 0.00 0.00 0.00 311.01 ?1: 15 6 5.9 85 . 15 U,1112 306.60 307.45 1.23 4.8: 0.36 ?0'J.47 0.6U 311.1117 0.07 036 310.50 0.00 0.27 0.00 0.00 310.24 311.8 16 15 33 95 12 11,0t2 307J11 30R37 0]9 4.14 027 31024 0.67 ?10.91 O.pS p27 31112 0.00 OA1 0.00 Q00 311.21 312.35 17 16 U.b 62 12 0.012 308.37 308.80 U99 U.82 O.U1 311.27 0.02 31L23 0.00 0.01 311.24 0.00 O.UU O.UU 0.00 311.24 3123 18 17 U3 127 ]2 OAl2 308.60 309.70 UJ9 0.43 ODU 317.2� 0.01 311.25 0.00 0.00 311.25 0.00 U.00 U.UU �I.1'10 311.25 3133 12 7 11 143 12 OAl2 307.15 308.01 OJ9 1.57 OA4 i1U,12 11.14 310.26 0.01 0.04 31031 0.00 0.02 0.00 U.UII 31U28 311.R 13 12 I.0 lU3 12 Q.U12 308.01 308.63 OJ9 1.21 0.02 31028 U,U6 310.33 0.0�� u.02 :a1037 0.00 0.01 0.00 U.00 31U37 312.3 l4 13 0.5 18'I 12 6.U12 30R.fi3 30990 0.79 0.65 0.01 31037 O.U3 31UJU U.UO b.01 31071 0.00 0.00 0.00 0.00 310.71 3133 4 vlt 4.R 94 18 0.012 304.60 30527 1,'77 2J1 0.11 309.00 0.17 309.17 0.02 0.11 309.30 0.00 U.11 O,OU 09q 309.19 311.2 � 5 4 4.8 160 18 0.012 30927 30fi.(17 177 2.71 0.11 309.19 02R 309.0.7 0.0: O.11 309.61 0.00 O.11 0.(10 01)0 3119.49 310.5 6 5 4.8 56 18 11.p12 30h.07 31)A35 IJ7 :91 0.11 309.M19 0.10 ?09.59 IL02 0,11 i09.73 0.00 026 0.00 0.00 309.47 312.6 7 6 3.2 60 12 0.p12 311b.RS 307.15 OJ9 4.06 0.26 309.47 0.41 ?09.88 O.US 11,2G 3111.1H 0.00 0.07 0.00 0.00 310.12 ?11.8 R 7 L6 1D0 12 0.012 307.15 3UZ65 0J9 2.OR 0.07 31012 0.18 310.29 0.01 0.07 31037 0.00 O.OS 0.00 0.00 31033 312.2 9 8 1.4 lUU 12 i1.1112 307.65 30R.15 0.79 1.74 QOS 31033 U12 31U.45 0.01 0.05 310.51 0.00 0.02 0.00 0.00 310.49 311,8 10 9 0.9 106 12 U.U12 3Utl.15 30RbR OJ9 1.20 OA2 310.49 0.06 310.55 0.00 0.02 710.Stt 0.00 0.00 0.00 0.00 310.57 312.2 11 10 03 Ift6 12 0.012 308.68 3U9.80 U79 U.43 0.00 310.57 0.01 3I0.80 0.00 Q00 31U.80 O.UU UAO 0.00 0.00 310.80 3133 8/17/04 PAGE i BACKWATER CALCULATIONS i, OIi NAME: Aegic SeIPStorsge and�ce,rrvisrd PREPARF.D BY: R.ST�;VHNS I OB NUMQER: 99121 DESIGN STORM: 100 YF.AR , ENTRANCE ENTRANCE EX1T OUTLET [NLET APPROACH RF.ND )UNCTION ��. PIPF. PIPE MANNQVG'5 OUTLET iNLET P�E FLOW VEL0CIITV TAILWATER FRICTION HCI. HEAD HEAD CONTROL CONTROL VELOCITY HEAU HEAD HEADWATER FROM TO FLOW LENGTH DIA. n ELEVATION ELEVATION AREA VELOCTTY HEAD ELEVATiON LOSS ELEVATION LOSS I.OSS ELEVATION ELEVATION HEAD LOSS WSS ELEVATION CB CB (CFS) (FEET) IN VALIiF. EET) FEET S FT (FT/SEC) (FEET) FEET EET) (FEET) FEET FEET FF.ET) (FEET FEET (FEET) (FEET FEET) RIM EL 1 vlt 2.1 9 12 0,012 307.50 307.77 U.7') 2.fi2 0.11 309.50 Q03 309.53 OA2 0.11 309.fi5 Q00 U,p2 0(�0 0.00 309.63 3I2 2 1 1.0 140 12 0.012 307.77 30R.61 099 1.24 0.02 309.63 0.09 309J2 0.00 0.02 311y,75 0.00 0.00 0.00 0.00 309]4 i12.4 3 2 0.2 59 12 U.012 308.61 3089G U99 0.25 0.00 3U9J4 OAO 309.96 O.UU U.00 30996 0.00 0,00 0.00 0.00 30')96 312.5 19 IS 3.1 122 l2 OAl2 iU7Jn 30R.43 OJ9 3.YG 024 31L16 0.78 31196 0.05 024 71225 0.00 OAO U.UU u.u0 31225 ?12 IS 6 20 85 13 0.012 306.60 307.45 123 5.69 0.50 31Q11 O.R4 31095 O.IU DSO 31L55 O.W 0.37 0.00 0.00 31Lt8 311.R 16 15 i,9 95 12 OAl2 30790 30H97 OJ'J 490 037 31L18 11.94 312.11 0.07 U37 31256 0.00 OA1 U.INI 0.00 312,55 31295 17 16 U.R h2 12 0.012 30N37 30R.R0 0.79 �H7 ILlll 31?.55 O.U2 312.37 0.00 0.01 312.5y 0.00 0.00 0.00 II.OU 312.59 3123 I8 17 0.4 127 12 0.012 3UR.H11 30990 0.79 0.51 0.00 71?.59 Q01 i12.1i0 U.00 0.00 312.6U O.UO 0.00 OAO 11.1111 312.60 3(33 12 7 1,5 14;3 12 O.U12 3117.15 30R.01 OA9 1.86 0.(15 311.03 0.20 31113 OAl 0.05 311.29 O.Uu 0.03 0.00 111111 311.26 311.8 13 l2 1,1 10;1 12 0.012 311R.111 30R.63 0.79 L44 IL03 3I126 OA9 31195 0.01 0.03 311.?9 n.�Ni 0.01 0.00 U.Uu 31138 3123 14 I3 0.6 l84 12 0.012 311R.G3 309.7U 0.79 0.77 O.DI 311.38 0.05 ?11.42 0.00 OAl 31L44 U.(�0 0.00 0.00 Olil� 311.44 3133 4 vlt 5.5 94 IR 0.012 3(W.8U 311517 1.7'7 3.17 0.15 309.50 0.22 309.72 0.113 0.15 309.90 0.00 U.IS 0.00 0.00 3U9J5 1112 I 5 4 5.5 160 IS U.Ul2 305.27 30A.07 1.79 3.1_l 11.15 309.95 0.38 31Q13 U.03 0.15 310.31 0.00 0.15 0.00 0.00 31U.16 310,5 �. 6 5 5.5 56 18 11.U12 30ti.07 306.35 1.77 3.13 Q15 310.16 n.13 310.29 0.03 0.15 310,47 0.00 036 0.00 o.uu 310.11 112.6 7 6 3.8 60 12 0.012 306.85 3U7.15 IIJY 4.R4 036 31U,1t O.SR 310.68 0.07 u36 311.12 0.00 0.10 0.00 OAO 311.03 ?t1.6 x 7 lA lD0 l2 0.U12 ,907.15 307.65 0.79 2.47 0.10 311.03 U.25 3112R 0.02 O.IO 31139 0.00 O.U7 OAU ii.00 311.32 312.2 9 R 1.6 100 l2 0.012 307.65 ?08.15 OJ9 ?.07 0.07 31132 0.18 311.SU 0!ll 0.0'7 311.SR U.UU 1Lf13 OAO 0.00 3I1.95 31I.R lU 9 Ll lD6 12 O.U72 30R.15 ]08.68 0.79 1.42 O.D3 311.55 0.09 311.64 O.OI 0.03 3ll,67 0.00 0.00 O.UO 0.00 311.67 312.2 I1 ]0 U.4 IRfi 12 0.012 30R.68 309.80 0.79 0.$1 O,f10 311.67 QU2 311b9 0.00 0.00 311.70 11.00 0.00 0.00 Q00 311J0 3133 xi i�ioa PA�E i :., � �R f :., ��, �1' , �, .. .��$"�� ..S` 1) / � ,. 1 !� ( . :� F r� f.r., ,�� �: ' �, ,�,r�-� �,r� � f.� { .. � ' 1�.� t. � � u.�i�7 f 3/`� ... � ;� �,/" ,.. �; '`" � � � � �4 . ° � f � ��,-. � , ,.;. <a tt' ^,, ,��• J , � �, ..� � y,.,v �, ��,.- J; f) 'J' ` V/ ..�� L � R �., r� ( t _,',Zy� . . � w� . ..!� .i^ .'+ � 1 ���' � C � O y .✓ ' �/'/ .u�,."�,.r O i� i, . . 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EROSION/SEDIMENTATION ANALYSIS AND DESIGN: T'he intent of this erosion and sedimentation control plan is to minimize erosion and the transport of construction related sediments off-site. The following ESC measures are incorporated into the Erosion Control design: 1. Clearing Limits: Clearing limits have been delineated on sheet C2.01 of the clearing and grading plans. The clearing limits extend only to those areas that will be disturbed during construction of the subject project. In general, clearing limits extend around the subject property. 2. Cover Measures: The temporary erosion and sedimentation control notes listed on sheet C2.31 specify specific times at which temporary and permanent cover measures will be installed. 3. Perimeter Protection: Per sheet C2.01, silt fence will be used for perimeter protection. Silt fence will be installed along the perimeters of those areas that will be receiving silt-laden runoff. 4. Traffic Area Stabilization: A construction entrance will not be installed at the entrance to the project site since the project will abut existing private asphalt and minimal ultilities will be needed. See sheets C2.01 and C2.31 for location of construction entrance and detail. 5. Sediment Retention: The detention/water quality vault will be used for sediment retention. Sediment retention will be designed per the 1990 KCSWDM Sediment Pond Calculations The runoff tributary to the sediment pond was calculated using WaterWorks hydrology software utilizing SBUH methodology. The soils on site consist of Arents, Everett material (An) and Gravel Pit according to the King County Soil Survey. See Section 2 of this report. According to the geotechnical consultant, the site has a large amount of fill atop the existing infiltrating soils. T'he site will therefore be considered to have pervious soils exhibiting characteristics of Type C soils. The precipitation rates used for this analysis are as follows: 2-year, 24-hour storm � 2.00 in. —used for sediment pond sizing 10-year, 24-hour storm —� 2.90 in. —used for riser sizing During the erosion control phase of the project, the site will be entirely cleared and will therefore be modeled as bare ground. The following information was used to create the runoff hydrograph from Waterworks: EROSION CONTROL PHASE Total Area= 1.6 acres GROUND COVER AREA(acre) CN Bare Ground 1.6 87 Time of concentration Assumed 10.00 min. The resulting hydrographs are: 2yr=028 cfs l0yr=0.56 cfs Surface Area: SA= 2080 sf/cfs * Q2 QZ =0.28 cfs SA= 2080 sf/cfs * 0.28 cfs =583 SF The designed sediment pond is 20' x 30' at the standpipe overflow elevation SA = 600 SF> 583 SF� OK Pond Geometrv: 3:1 interior side slopes 2.3' depth 'The top of the sediment storage is EL 309.6. The elevation of the top of the standpipe is EL 311.9 (2.3 feet of depth). The bottom of the pond is 308.6 (1 foot of sediment storage}. • Riser Pipe Design Flow =Q�o=0.56 cfs Tfie flow capacity for a 12" diameter riser with 1 foot of head is approx 3.8 cfs»0.56 cfs required. • Emergency Overflow Spillw�ay Design Flow = Q��=2.85 cfs (from rational method analysis in ' conveyance section) II H =0.4' L= (Ql�/3.21H3�2))-(2.4H2) _ (2.86/0.812)—(0.384) = 3.2 The overflow spillway shown on the plans is 6 feet wide>3.2 required. • Dewatering Orifice: Orifice area=AS(2h)o.s/(0.6)(3600)Tg0.5 _ (600)(2*2.3)o.s/(0.6)(3600)(24)(32.2)o.s =0.00437 sf Orifice diameter=24(orifice area/n)o.s =24(0.00437/n)o.s =0.89 inch. USE 1 inch min. 8/18/04 12 : 57 :24 am page 1 PHASE 2 STOR-HOUSE SELF STORAGE 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- BAS IN SUMM��RY BASIN ID: EROS002 NAME : EROSION CONTROL 2 YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 60 Acres BASEFLOWS : 0 . 00 cfs R.AINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 2 . 00 inches AREA. . : 1 . 60 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 87 . 00 0 . 00 TC. . . . : 10 . 00 min 0 . 00 mi. ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 28 cfs VOL: 0 . 12 Ac-ft TIME: 480 min BASIN ID: EROSOIO NAME: EROSION CONTROL 10 YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 60 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 2 . 90 inches AREA. . : 1 . 60 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 87 . 00 0 . 00 TC. . . . : 10 . 00 min 0 . 00 min ABST�RACTION COEFF: 0 . 20 PEAK RATE: 0 . 56 cfs VOL: 0 . 22 Ac-ft TIME: 480 min �C � A z w a a � �- .; � : ' '� � ; i __ � �l � ,_ ; �_ � ( i � STORM DRAINAGE ANALYSIS � , FOR ' RENTON MINI STOR.AGE ' RE�TOV, `V<�SI1[\G'TOv � N �.'�� ` �►'�' I�;1 , W 261 4 'Po .Q����Q �{v G,� j i� �� �`���NAL�N 1� � l �EXPt�REs�2-04- � Prepared by: Gina R. Brooks, P.E. & Robert H. Stevens, P.E. Approved by: Robert H. Stevens,P.E. Date: September 2001 Core No.: 99121 �-} I RENTON MINI STORAGE TABLE OF CONTENTS l. Project Overview 2. Off-Site Analysis 3. Detention and Water Quality Facility Analysis and Design 4. Conveyance System Analysis and Design 5. Erosion/Sedimentation Analysis and Design 6. Core and Special Requirements � � 1. PROJECT OVERVIE`V: Renton Mini Storage is located on the south side of NE 3`� Street approximately halfway between Edmonds Avenue N and Jefferson Avenue N in Renton, Washington. See attached vicinity map. The 7.77 acre property is currently vacant. Former use of the site was first as a gravel quarry and then as a land fill. The existing ground cover is dead grass and weeds. The ground slopes from east to west at an average slope of approximately 4% across the majority of the property. Along the west boundary of the property slopes are in excess of 100% and slope down to a hole located along the west property line. The developer proposes to construct a storage unit facility and two office buildings with associated roadway and utilities. An area referred to as Phase 2 will be reserved for future development. For the purposes of storm drainage calculations, this area will be considered to be developed as a mini storage facility. This assumption is conservative yielding a higher percentage of impervious area. See attached site plan. The on-site generated runoff will be directed to a water quality/infiltration vault located at the north end of the site near NE 3'�Street. The infiltration vault will be designed to infiltrate up to the developed 10-year, 24-hour stonn. Storms exceeding the 10-year, 24- hour storm will be allowed to overflow into an overflow conveyance system that will route excess flows to the existing NE 3`� Street tightlined conveyance system. � � 0 a 1 � 4; Q 405 �,5`� �� , Q h �J��� z W � � � z � � Q � - � Q � � N.E 4 TH 900 S,��ET S7REET Q N .�Ro sr. 3Ro � E ���(0� A/RPORT{yY -9� N g 5• �; P�,• �� 5� �� sirE �'�sr. 0����. 5���� S. 3RD. ST. �' ``j ��. � � 167 Q 169 ��ti�'o� Z - -9 � Q _ <<F��q,o P '4'O�F i G wAY � S.w �RADY � �m 515 �o v,Z !//C/NITY MAP �= zsoo' N Page 1 of 2 King County Building and Land Development Division - TECHNICAL INFORMATION REPORT (TIR) WORKSHEET - . . � - . . . - . . � . ProjectOwner Northward Properties ProjectName �nton Mini Storage Address 1560-140th Avenue NE,#100 Location Phone 425-747-1726 Bellevue, 4�, 98005 Township 23N Project Engineer �n}-�rt u c����� � �� Range 5E Section 16 Compan�re Desicm, Inc. ProjectSize �•�� AC q�d Phone 4205-148th Avenue NE,#200 Upstream Drainage Basin Size �� g AC 425-���-7877, Bellevue WA 98007 ` . • . � Subdivision 0 DOF/G HPA 0 Shorefine Management 0 Short Subdivision 0 COE 404 � Rodcery � Grading � DOE Dam Safery � Structural Vaults � Commeraal � FEMA Floodplain � Other 0 Other � COE Wetlands � HPA • � . - Community Newcas _lP Drainage Basi� �v� �] River U Floodplain ; 0 Stream 0 Wetlands I � Critical Stream Reach 0 Seeps/Springs 0 Depressions/Slrvales � High GroundwaterTable � Lake � Groundwater Recharge � Steep Slopes 0 Other � Lakeside/Erosion Hazard • Soil Type Slopes Erosion Potential Erosive Velocities I� Arents, �erett Mat'1. (An� 1 evel��tle G1 ;r,q G,�.;� I Fill 0-1000 � Additional Sheets Attatched 1/90 Page2of2 I King County Bullding and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET � . • . REFERENCE LIMITATIOWSITE CONSTRAINT I, � � Ch.4-Downstream Analysis � � � a 0 0 � Additional Sheets Attatched � MINIMUM ESC REQUIREMENTS MINIMUM ESC REGZUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTiON � Sedimentation Facilities � Stabilize Exposed Surface � Stabilized Construction Entrance 0 Remove and Restore Temporary ESC Faalities � Perimeter Runoff Control � Clean and Remove All Sitt and Debris � Clearing and Grading Restrictions � Ensure Operation of Pennanent Facilities � Cover Practices 0 Flag Limits of NGPES � Construction Sequence � Other � 0 Other � � 0 Grass Lined Channel � Tank � Infiltration Method of Analysis � Pipe System �XI Vault � Depression ��� I 0 Open Channel � Energy Dissapator 0 Flow Dispersal Compensation/Mitigation �! 0 Dry Pond � Wetland 0 Waive� of Eliminated Site Storage 0 Wet Pond � Stream 0 Regional Detention Brief Description of System Operation �aina9e will be collected by tightlined drai.naqe �st�n and conve:�g3 tr� water �al i �fin�;l�ati_on vault. Facility Related Site Limitations � Additional Sheets Attatched Reference Facility Limitation � - . . - � Drainage Easement � Cast in Place Vault � Other Q Access Easement 0 Retaining Wall � Native Growth Protection Easement � Rodcery>4'High Q Tract 0 Structural on Steep Slope Q Other • - . • I or a avil engineer under my aupervision have visited the site. Adual � � _ - site conditions as observed were incorporated into this worksheet and the -� , (���' attatchments. To the best ot my knowledge the iniormation provided here is accurate. 1/90 2. OFFSITE ANALYSIS: Site visits were conducted during the Fall of 2000. See the attached Upstream Basin Map. lipstream Tributary Area Tributarv to Site: There is currently a small upstrcam tributary area that is east of the site. It is assumed due to the high infiltrating soils within the tributary area that none of the upstream drainage reaches the site. -- Tributarv_to Fronta�e: ' Proposed development of the site will include connection of a proposed overflow system to the existing NE 3`� Street conveyance system that will convey drainage exceeding the developed 10-year, 24-hour storm event. The drainage basin upstream from the proposed point of connection to the existing system along NE 3`� Street was determined based on ', as-built information provided by the City of Renton. As-built information for the 1984 Street Improvement Project along NE 4`h Street and Monroe Avenue NE shows that the existing drainage basin extends from the site and east up NE 3`d Street/NE 4``' Street to Monroe Avenue NE. Along Monroe Avenue NE and NE 4`'' Street, a 36"storm drainage system was installed and channeled to an infiltration facility thereby diverting any collected drainage, that was originally collected by an existing 12" conveyance system, away from the site's frontage upstream basin. The existing 12" conveyance system along NE 3`d Street and tributary to the subject site's frontage is used as an emergency overflow route for the infiltration facility should the system fail. It is assumed for the purposes of determining the upstream tributary area that the infiltration facility for the 36" conveyance system will not fail and will not overflow into the existing 12" conveyance system on NE 3`� Street. With the installation of the 36" conveyance system, a small area that was collected by the existing 12" storm drainage system along Monroe Avenue NE was not rerouted to the 36" storm drainage system at the time of installation along Monroe Avenue NE north of NE 4`h Street. Thereby, the existing 12" conveyance system still discharges into the existing 12" storm drainage system along NE 4`'' StreetlNE 3'� Street. The remaining information for determining the upstream basin area was extrapolated from the City's Utilities Division section maps. The upstream basin area is delineated on a copy of one of the City's Utilities Division section maps and attached on the following pages. i, r /' rv ��'�; `J`` I ,�k1 Y�,�\ '�� �p���� � �l l � ( , �1 <...' , �.,-\ 1 / � ' 1/ � 'II�. . �1 lpl�il � i �i.....� �/�. / ` I I"`I '\`"...�I�IH",i� �\ _/) � .1 \ . . � � � f��� i ' I� �.-' � �1 l, 1 i l y !\� �i�il} � li . �� !( ��4i•. �\ � _��. \ � 1 . i i , ��t�, r, ,I� � r F i. � . �;, / �,, - ,,a ,.., � -- � \ l I l 'r' j 1�ir .� \� J�4F�1�JI�I� i 'L' �.�:,\ ! " �1���' ��IL '- ' �.��.. � i,� �� 1 I � �� !�( 9 ) III/ iUAip ��� �.�•\ / i��' �i//� Wr►� �) _ � ._ ��, .I `.�� /�//� t",,�. �IJ'�+I � `� \��li���� Ii.l� `f \�\\\ /s�^'rr{v��•�d; v C� _ `Y�' • i I� • . 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I�� If . , J 81-Lltl, �/ f=t7t` ., `,� •. 71 L3'CP .� 'J�l ...-� _., ��. � 1.-� �,l. . -; �� a-[7ei �� '' ,I ..;� v..'( . ; i� �i.._', -� •--tt- � � � \r I �2; �:� s' - `�. � � .,, ��i � \ �� 'v' �.��- � �11. �.., �.�x� ��� I l �� `, ' * � �F a � �a rcl \ ,`�, . 1 ��. . - � � �i j- .i -;� .. , i' oi-e�'iz i•c. �, �i cri � :I ; i o_ 1 _ � � ` � ;'���u�r � 1'` r .. t 1' �' I,�.- � + - _�.; � a' ��� ,... _ �`` �' 1` i / I _ ,,.. � , \ \ - � \\ I �,� �� � � �1 . ;.. ._., �. _., . ._ o ,�, �r l � �� l `� � i\ 4 e-t7c y , ` j ; '�� � � . xa.0 � � ��\ � J; \ ) llil)�c ��i � l � r .- .__ � ,. _. � a"1 i �, l ;,` y /''.�^1 r ._. \`}i ,E . -- -�'t, - -... 1 , 1' Downstream Analysis Resource Review The proposed project is located within the Cedar River Basin. Resources listed in the KCSWDM were reviewed for existing/potential problems within the study area. The study area is that area associated with the upstream drainage system that is tributary to the point of connection of the proposed onsite drainage system to the NE 3`� Street drainage system and downstream along NE 3`� Street %-mile from the subject site. FEMA Maps: FEMA map dated may 16, 1995 numbered 53033C0981F was reviewed. There are no - flood areas within the study area. Sensitive Areas Folio: The December 1990 Sensitive Areas Map Folio was reviewed to confirm whether or not the study area is located within a wetland, stream or flood hazard area, erosion hazard area, landslide hazard area, seismic hazard area, or coal mine hazard area. There are no wetlands, streams or flood hazard areas, erosion hazard areas, landslide hazard areas , seismic hazard areas, or coal mine hazard areas within the study area. ' Drainage Complaints: Per the City of Renton, there are no reported complaints within the study area. King County Soils Survey: The soils on site consists of Arents, Everett material (An) and Gravel Pit. Soils within '/- mile downstream include Gravel Pit and Everett gravelly sandy loam (EvD). Soils upstream and tributary to the 12" storm drainage line along NE 3'� Street consists Arents, Everett material (An) y"P v + f '�—/��/� � { \ \\ 4r � T '.' ���r e— r �I � � S� , u� • ' � �. � ` r o - : 4 C � i i� _�� � : . 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' � _< \�� AgD�, \�1`� •\ I : ••►•�% �_'' P ` '� o_� - �" o Substa i AmCi � �� �ra �'-- -- ��_� .\ � �. ., i, C . �'. '�- _1 �gc �_ •__ __ �. �o Jl���,_akr=:;� , ap ;;.. .; :1�8 :�� � s � `. �, `� �'3�,� pv ' ,e �� .i � o � � �Ag� 2� 455 \\�o\/i°/ 2� I\`<, / � \ � � .� � : � 9�. C< rt I II I ° � n�� �c \° '�� �,° . .AkF � �-,`�.\�� � ��� �`�a � o`��) �� '• ___ �•� • \\ .p° I q�C �� � AkF ,Q, . ''. \ 11 \�`` `I 1� ( I Pu \ .. •ti� �a o e a 515` ' AQVE \\���� � I ,j-=_„ ' � 6 � y�� i_ eD� au� ;vBeC � � "� ��`di 1�0'o �vC / i '• ""• �"0 1 0(,�go �����',` i . :I \ 1 �� °� � `�� e �-__��1 M e ` '-. � � 'II�� B -��',4 -----' --- ��--- --- -- � 2 �� `�qI�K � — — — �z�� � =�-- ----a ,,, a6 C� � �, — a� .,, \ � �� � l ,' � � t e�� ^ Agc � � ` D � � � � , ��o -� � ' Tu z� � Sk a.. I . ��J(`� qgC I Agp , r G � ��� V eMo ; ���, ' C- . v�--� aza ��`� \ � � � � �� ° AmC � � q g` �� _'�g �203 �C •2�• � AgB` A � � �Ur � � � `� I� � Sk ` • I ° •�. e ° 451 � �� � � � � � I � Ur =o= � o IAgC r��� No I o /�p �r° � � ���r � .AmC 'r/� A 0�`B�e . "`���` e;' :c`�� i G/. i \ � y�� ���U ' C�e. 'nC ��- �� Ag8 � _, ° 'a��}; ,_ S(''h� ��� �� ��� ( ��� f'�\"�'d�:� I� �'� ' lj' � °�`-� 1 i��°o � *"�''4,�/ama �� e ��,e��r�K��� HING COUNTY � �,' i -- � v�M�����. �__ —se—' � ' �',�� �-- -- =�,• �'--: SOIL SURVEY '� _ ` 'I � , . , �� � ,,-� e��T , „� t �� e/• r% �M�94 a e � o �� o i: ;,�� � `�;� � a ', , RENTON MINI STORAGE ^�� �, ,` � �) � '(�•", e � `'' � ,9 '!� ,�' 1s''��3` (�a�,s' �r� � �`_:_� ��� CORE PROJECT NO. 99121 a ! Y -,`, � ° ��o ,, .l�t�� . ;'� '' � � ° a��,e \� 4 �' ', , -- • ,��i ,iii° c)'� .Fi �.i , a�\1m� �� i �,gJ� , oo e oe�e ' o 1������gC i� l��� ;}� �'%f` � f' o v, ` � ��,'° I �� �f,io I� si � } .. � �',�e�e.._�.,CI�.=IIOO;4.,�ilo..., ;'�` �` "°II" , , „�;�•�`I' ''V; 'J�,,B` . ��`'tr � � " ^.` �li i � � . . . _ �� �.�' / � _ �t _ _ ,i� Do�vnstream Drainage Route The proposed conveyance system for the subject site will allow flows over the 10-year, 24-hour storm event to discharge to an existing catch basin located on NE 3rd Street. The downstream drainage route was confirmed per as-builts provided by the City. Per the City of Renton East Renton Sewer Interceptor, existing 12" storm drainage is shown schematically on the plans to a point approximately 450 feet downstream or west of the subject property's northwest property corner. It has been confirmed by field survey that 12" storm drainage fronts the subject property. It is unclear though based on limited information of the pipe network along NE 3`� Street when the size of pipe changes from 12" to a larger diameter pipe. T'he downstream system travels downstream west along � NE 3`� Street and then turns southwest near the intersection of Sunset Avenue NE. The drainage continues to travel southwest where it eventually reaches Cedar River. No existing problems along the downstream drainage route, Y-mile downstream from the subject site, have been documented with the City of Renton, nor is there any evidence in the filed of the system being under capacity. The shallowest slope along the existing 12"storm drainage system along NE 3`� Street is immediately downstream of the point of connection for the proposed onsite storm drainage system. Capacity of the existing storm drainage system along this length of pipe will be analyzed following the infiltration vault sizing in Section 3B of this report. NE 3`� Street continually from the point of connection steepens in slope. The point at which the slope within the existing storm drainage system may level out is near the intersection of Sunset Avenue NE. At this point, the drainage from the subject site constitutes less than 15% of the total drainage within the existing system. � . � � _ 1 � 3. DETENTION AND WATER QUALITY FACILITY ANALYSIS AND DESIGN: A. Hydraulic Analysis The drainage analysis was modeled using WaterWorks hydrology software utilizing SBUH methodology. The soils on site consist of Arents, Everett material (An) and Gravel Pit according to the King County Soil Survey. See Section 2 of this report. According to the geotechnical consultant, the site has a large amount of fill atop the existing infiltrating soils. The site will therefore be considered to have pervious soils exhibiting characteristics of Type C soils. The precipitation rates used for this analysis are as follows: Water quality storm (dead storage) = 2-year, 24-hour storm =3 —� 0.67 in. 2-year, 24-hour storm —� 2.00 in. 10-year, 24-hour storm—� 2.90 in. , 25-year, 24-hour storm� 3.40 in. ' 100-year, 24-hour storm � 3.90 in. EXISTING CONDITIONS I The property is currently vacant. The existing ground cover is dead grass and weeds. DEVELOPED CONDITIONS The developer proposes to construct storage units and office buildings with associated ' roadway and utilities on 7.77 acres. The west 50 feet will continue to slope and drain to the west. This west 50 feet, 0.77 acre, is not included in the storm drainage calculations. �- The impervious and pervious areas were measured with a planimeter. The pervious portion of the site was assumed to be lawn and landscaping, good condition. The following information was used to create hydrographs in WaterWorks (also see attached �printouts). DEVELOPED CONDITIONS Total Area= 7.0 acres GROiJND COVER AREA(acre) GN Lawn & Landscaping 0.6 86 Impervious 6.4 98 T'ime of concentration 5.60 min. • � � . . � . � . rM � �• S ' �, 1 ► s.������ `�� �E���� � �, �-- r #�!rt�i -� y. -:��-��� ` ..�,,. , ��■��� M� � �� � � �� : ����� r��a ,� � � ���' � ,w��� � � ` ����— � /.�►i ��. � ���� � � � � , ► � d . . =���.■ E:� � � • �•�. \� .. � • � ����� -�.�Iw� � �� .A �� `� � � t� � ��� ' �'i����l���� �s �, A"�� � � , ��"�1 ��,a=�� r������ �l a `�`�, ' �r— � ��•:� I►i���•7f .� ,+� , ��� �a � �� J � � 'I ~ f � � �;�-���_•:�� �I __ \ ������� �_ ��/�II��?�ill��� .�� ` �' a�j��� , �.�•���• yE.'-r?y� �`i�� ����I�1�� ��r�� `��:�1��� ���!'"�� � ��'+'�•� � 1 � � ����� �1������_ ���������/������� ��, ���V� ' ��r ` � �/���1l�a � ��� �i � •�_ ������'�� �-� ,i� � �' i ��► i� �I!!� ���.—��—.I���_ � �- ►� � , � ,�► ��'°�.�"'�'� ' �•1. �� �.- �1i►�, .1�1�� ..���, � � � . 1 f�. . �11 '-�� I �u�,�. � , �' F '�, � R � ��� � / �� ,��E ��� � � � ��� � ��, :. �.1��� �,�.+���_ �� i� ��ri �i� � '��l. 3 �,:,�,, �! �■� � � _ o � � ��, ,,�� �,�, r,r-��`�� - �,. 1��1► ��� �,�� \���` � �� ��I�f � � � .. �, _ � ��%� ��''��� ���, l ,�1/�_ ���.�`� �►. 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' l, �: � "w>.............. .. ., ..._ ... ..._... ...�___....._�--- .._.r....,.__- '_ ..._.. ,�-... � � .. �•'-, + � �� s z__ :'- _. ..ev.d.r _.__ '� .-•� ' . . ..�,._�..� �.,_...__. .,...�...� .._ _ .. ..s., " _ � /Y �\ 3�&� �3'.__..�' �'�, .. -•��"_.. �_�.� '� --;._. _... � r ... ._ •-.__�__.... � ' �i _ " � a. .�.�- . . ¢:_ r"���(}�� - " o. . ., . - ... ��� `+� _ . � . �.-�. . _.- a-""-✓-"'�..,='-'--.r"..,_-�_ . �_. ,�_ , i �.� , 'M P ._.� : � ---______._ _..�._.__. .r.�,.,,.,., �_ _�_ 32f -___ _ 4`'^ ' ---=__... . ..__... �.__. _ _._ ___ ____ - _ --__ ______ , . _ _ SITE PLAN RENTON MINI STORAGE CORE PROJECT NO. 99121 l�J/ �/UL 2 . _ _ . �� �;n � �u .� I�;t� _ ._��z��� , _._��_����� ��_ ��, i���� _ . =EI��iOI�I l�'II'�TI STGF�?GE CORE NO. 99121 __________________________==�::STp,; �L�,11.��Ri=====______________________= I �,� . � ,, ��� �� - „ �I BAS II��1 IL- : DEti��J:.0 Nr:•i� . �E��'�L,�,_`�,J �0 r E!-�_�� E'J�N�' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7 . 00 Acres BASEFLOWS : 0 . 00 cfs ' RAINFALL TYPE. . . . : TYPElA PERV II�IP PRECIPITATION. . . . : 2 . 90 inches AREA. . : 0 . 60 Acres 6 . 40 rc-�_: TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 � TC. . . . . 5 . 60 min 5 . 60 min ABSTRACTION COEFF: 0 . 20 ' TcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: � . ���0 .� : U . �2:�C � TcReach - Channel L: 670 . 00 kc :42 . 00 s : 0 . 0050 � impTcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr : � . Ou s : Q . 0�00 �' impTcReach - Channel L: 670 . OQ kc :42 . 00 s : 0 . 0050 i PEAK RATE: 4 . 04 cfs VOL: 1 . 50 Ac-ft TIME: 480 m�r_ ', BASIN ID: DEV025 NAME: DEVELOPED 25 YEAR EVEI: II SBUH METHODOLOGY � TOTAL AREA. . . . . . . : 7 . 00 Acres BASEFLOWS : O . uU cr� RAINFALL TYPE. . . . : TYPElA PERV i��:r PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 60 Acres 6 .40 :'_ �_ TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 TC. . . . : 5 . 60 min � . Fr � ABSTRACTION COEFF : 0 .20 I TcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: �I TcReach - Channel L: 670 . 00 kc :42 . 00 s : 0 . 00� ', impTcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2y '; impTcReach - Channel L: 670 . 00 kc :42 . 00 s : O . Gu�O �, PEAK RATE: 4 . 79 cfs VOL: 1 . 79 Ac-ft TIME: 480 m; ! BASIN ID: DEV100 NAME: DEVELOPED 100 YEAR EVENT SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0 . 60 Acres 6 .40 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 TC. . . . . 5 . 60 min 5 . 60 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0200 TcReach - Channel L: 670 . 00 kc :42 . 00 s : 0 . 0050 impTcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0200 impTcReach - Channel L: 670 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE: 5 . 54 cfs VOL: 2 . 08 Ac-ft TIME: 480 min B. Infiltration Calculations and Overflow Analysis INFILTRATION CALCULATIONS The on-site generated runoff will be directed to a water quality/infiltration vault located at the north end of the site near NE 3`d Street. Infiltration within the water quality/infiltration vault will be used for mitigation of the stormwater to meet Core Requirement #3 of the 1990 King County Surface Water Design Manual. The bottom of the vault will be located at a depth that will take advantage of the existing infiltrating or I Type A soils that are currently under the existing fill. The infiltration vault will be designed to infiltrate up to the developed 10-year, 24-hour storm. Storms exceeding the 10-year, 24-hour storm will be allowed to overflow into an overflow conveyance system that will route excess flows to the existing NE 3�d Street tightlined conveyance system. I Therefore, the allowable release from the vault for the 100-year, 24-hour storm is the difference bet�veen the 100-year peak flow and the 10-year peak flow. The existing 12" storm drainage system along NE 3rd Street will be analyzed at the end of this section to verify capacity. The vault will be designed according to the 1990 KCSWDM. The soils have been shown to infiltrate at a rate of 24.5 inches per hour. The infiltration vault ��vill be sized at the maximum allowable rate of 20 inches per hour per Table 4.5.2 of the 1990 KCSWDM. The infiltration portion of the vault has a surface area of 2,000 square feet. Of this 2,000 square feet only 1,650 square feet is available for infiltration due to construction of the footings and grade beams. The amount of drainage infiltrating is therefore equal to 20 in./lir.*hr./3600 sec.*ft./12 in.*1650 sf= 0.76 cfs. The routing results are summarized as follows (see attached WaterWorks printouts on the follo��ving pages): ROUTING RESULTS 10-YR, 24- 25-YR, 24-HR 100-YR, 24- HR STORM STORM HR STORM Q inflow into vault (cfs) 4.04 4.79 5.54 Q overflow (cfs) See Hyd. 3,7 0.00 1.15 2.70 Vault live storage required (CF) 16,110 16,676 17,220 10/1/Ol 1 :23 : 5 pm Dodds Engineers, Incorporated page 1 RENTON MINI STORAGE CORE NO. 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib � NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres -------------------------------------------- --------------------------------------------- 1 0 . 7 6 0 3 2 0 6 5 4 5 8 c f 7 . 0 0 I 0-YEAR INFILT. , 2 1 . 9 0 9 5 4 0 7 7 9 6 8 c f 7 . 0 0 25-YEAR INFILT. + OV ERFLO W ' 3 1 . 14 9 5 4 0 7 3 9 6 c f 0 . 0 0 25-YEAR OVERFLOW 4 0 . 7 6 0 2 8 0 7 0 5 7 2 c f 0 . 0 0 25-YEAR INFILT. ' 5 3 . 5 8 5 4 8 0 7 7 8 3 3 c f 11 . 8 0 25-YEAR OVERFLOW+UPS025 6 3 .4 6 0 5 0 0 9 0 5 0 5 c f 7 . 0 0 100-YEAR INFILT.+OVERFLOW I 7 2 . 700 500 16280 cf 0 . 00 100-YEAROVERFLOW ��, 8 0 . 7 6 0 2 3 0 74 2 2 5 c f 0 . 0 0 100-YEAR INFILT. 9 5 . 2 7 8 5 0 0 1012 0 0 c f 11 . 8 0 100-YEAR OVERFLOW+UpS100 10/1/Ol 1 : 23 : 5 pm Dodds Engineers, Incorporated page 2 RENTON MINI STORAGE CORE NO. 99121 STAGE STORAGE TABLE RECTANGULAR VAULT ID No. VAULT Description: INFILTR.ATION VAULT Length: 100 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 STAGE <---S2'ORAGE----> STAGE <----STORAGE----> STAGE r--STORF.GE----> STAGE <----STORAGE----> (ft) --cf--- -Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- -Ac-Ft- -------------------------------------- 300.40 0.0000 0.0000 302_90 5000 0.1148 305.40 10000 0.2296 307.90 15000 0.3444 300.50 200.00 0.0046 303.00 5200 0.1194 305.50 10200 0.2342 308.00 15200 0.3489 300.60 400.00 0.0092 303.10 5400 0.1240 305.60 10400 0.2386 308.10 15400 0.3535 300.70 600.00 0.0138 303.20 5600 0.1286 305.70 10600 0.2433 308.20 15600 0.3561 300.80 600.00 0.0164 303.30 5800 0.1331 305.60 10800 0.2979 308.30 15800 0.3627 300.90 1000 0_0230 303.40 6000 0.1377 305.90 11000 0.2525 308.40 16000 0.3673 301.00 1200 0_0275 303.50 6200 0.1423 306.00 11200 0.2571 308.50 16200 0.3719 ?G1.10 1400 0.0321 303.60 6400 0.1469 306.10 11400 0.2617 308.60 16400 0.3765 3G1.20 1600 0.0367 303.70 6600 0.1515 306.20 11600 0.2663 308.70 16600 0.3811 3G1.30 1900 0.0413 303.80 6800 0.1561 306.30 1180Q 0.2709 306.80 16800 0.3857 301.40 2000 0.0459 303.90 7000 0.1607 306.40 12000 0.2755 306.90 17000 0.3903 301.50 2200 0.0505 304.00 7200 0.1653 306.50 12200 0.2601 309.00 17200 0.3949 3D1.60 2400 0.0551 304.10 7400 0.1699 306.60 12400 0.2647 309.10 17400 0.3494 301.70 2600 0.0597 304.20 7600 0.1745 306.70 12600 0.2893 309.20 17600 0.4040 301.60 2B00 0.0643 304.30 7800 0.1791 306.60 12800 0.2938 309.30 17800 0.4086 3C1.90 3000 0.0689 304.40 8000 0.1837 306.90 13000 0.2964 309.40 18000 0.4132 302.00 3200 0.0735 304.50 8200 0.1882 307_00 13200 0.3030. 309.50 18200 0.4178 362.10 3400 0.0781 304.60 6400 0.1928 307.10 13400 0.3076 309.60 18400 0.4224 3!'2.20 3600 0.0626 304.70 6600 0.1974 307.20 13600 0.3122 309.70 18600 0.4270 302.30 3800 0.0672 304.60 8600 0.2020 307.30 13600 0.3168 349.60 18800 0.4316 3^2.40 4000 0.0918 304.90 9000 0.2066 307.40 14000 0.3214 309.90 19000 0.4362 3G2.50 4200 0.0964 305.00 9200 0.2112 307_50 14200 0.3260 310.00 19200 0.4408 3�2.60 4400 0.1010 305_10 9400 0.2158 307.60 14400 0.3306 3�2.70 4600 0.1056 305.20 9600 0.2204 307.70 14600 0.3352 302.80 4800 0.1102 305.30 9800 0.2250 307.80 14800 0.3398 10/1/Ol 1 :23 : 5 pm Dodds Engineers, Incorporated page 3 RENTON MINI STORAGE CORE NO. 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. COMBI Description: Structure: INF Structure : Structure: RISER Structure : Structure : STAGE <--DISCHARGE---> STAGE <--DZSCH:.RGE--> S:AGE <--DISCHi.RGE---> STAGE <--DISCFIr^.P.GE---> ;ft) ---cfs-- ------ (ft) --cfs-- ------- (ft) ---cfs-- ------ (ft) ---cfs-- ------ 300.40 0.7600 302.90 0.7600 305.40 0.7600 307.90 0.7600 300.50 0.7600 303.00 0.7600 305.50 0.7600 308.00 0.7600 300.60 0.7600 303.10 0.7600 305.60 0.7600 308.10 0.7600 300.70 0.7600 303.20 0_7600 305.70 0.7600 308.20 0.7600 300.80 0.7600 303.30 0.7600 305.80 0.7600 306.30 0.7600 300.90 0.7600 303.40 0.7600 305.90 0.7600 308.40 0.7600 301.00 0.7600 303.50 0.7600 306.00 0.7600 308.50 0.7600 301.10 0.7600 303.60 0.7600 306.10 0.7600 308.60 1.0680 301.20 0.7600 303.70 0.7600 306.20 0.7600 308.70 1.6311 ' 301.30 0.7600 303.80 0.7600 306.30 0.7600 308.80 2.3603 301.40 0.7600 303.90 0.7600 306.40 0.7600 308.90 3_1519 301.50 0.7600 304.00 0.7600 306.50 0.7600 309.00 3.4343 301.60 0.7600 304.10 0_7600 306.60 0.7600 309.10 3.6695 301.70 0.7600 304.20 0.7600 306.70 0.7600 309_20 3.9242 301.80 0.7600 304.30 0.7600 306.80 0.7600 309.30 4.1427 301_90 0.7600 304.40 0.7600 306.90 0.7600 309.40 4.3479 302.00 0.7600 304.50 0.7600 307.00 0.7600 309.50 4.5420 302.10 0.7600 304.60 0.7600 307.10 0.7600 309.60 4.7266 3D2.20 0.7600 304.70 0.7600 307.20 0.7600 309.70 4_9030 302.30 0.7600 304.60 0.7600 307.30 0.7600 309.80 5.0721 302.40 0.76Q0 304.90 0.7600 307.40 0.7600 309.90 5.2349 302.50 0.7600 305.00 0.7600 307.50 0.7600 310.00 5.3920 302.60 0.7600 305.10 0.7600 307.60 0.7600 302.70 0.7600 305.20 0.7600 307.70 0.7600 302.50 0.7600 305.3C� 0.?000 307.80 0.?5GG 10/1/O1 1 : 23 : 5 pm Dodds Engineers, Incorporated page 4 RENTON MINI STORAGE CORE NO. 99121 STA�E DIcCHpRr� TA�L- Description: INFILTRATION RAT STAGE �--DISCHARGE--> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---cfs- ----- (ft) ---cfs-- ----- (ft) ---cfs-- ------ (ft) --cfs- ------ -------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- 300.40 0.7600 302.90 0.7600 305.40 0.7600 307.90 0.7600 300.50 0.7600 303.00 0.7600 305.50 0.7600 308.00 0.7600 300.60 0.7600 303.10 0.7600 305.60 0.7600 308_10 0.7600 300.70 0.7600 303.20 0.7600 305.70 0.7600 309.20 0.760Q 300.80 0.7600 303.30 0.7600 305.80 0.7600 308.30 0.760 300.90 0.7600 303.40 0.7600 305.90 0.7600 308.40 0.% 301.00 0.7600 303.50 0.760D 306.00 0.7600 306.50 O.f 301.10 0.7600 303.60 0.7600 306.10 0.7600 308.60 0." 301.20 0.7600 303.70 0.7600 306.20 0.7600 308.70 0.7c � 301.30 0.7600 303.80 0.7600 306.30 0.7600 308.80 0.7600 301.40 0.7600 303.90 0.7600 306.40 0.7600 308.90 0_7600 301.50 D_7600 304.00 0.7600 306.50 0.7600 309.00 0.7600 301.60 0.7600 304.10 0.7600 306.60 0.7600 309.10 0.7600 301.70 0.7600 304.20 0.7600 306.70 0.7600 309.20 0.7600 ' 301.60 0.7600 304.30 0.7600 306.80 0.7600 309.30 0.7600 301.90 0.7600 304.40 0.7600 306.90 0.7600 309.40 0.7600 302.00 0.7600 304.50 0.7600 307.00 0.7600 309.50 0.7600 302.10 0.7600 304.60 0.7600 307.10 0.7600 309.60 0.7600 302.20 0.7600 304.'70 0.7600 307.20 0.7600 309.70 0.7600 302.30 0.7600 304.80 0.7600 307.30 0.7600 309.80 0.7600 302.40 0.7600 304.90 0.7600 307.40 0.7600 309.90 0."' 302.50 0.7600 305.00 0.7600 307.50 0.76C' ". 302.60 0.7600 305.10 0.7600 307.60 0_76 302.70 0.7600 305.20 0.7600 307.70 0.76 10/1/Ol 1 :23 : 5 pm Dodds Engineers, Incorporated page 5 RENTON MINI ST�RAGE CORE NO. 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- STAGE DISCHARGE TABLE RISER DISCHARGE ID No. RISER Description: OVERFLOW RISER Riser Diameter (in) : 12 . 00 elev: 308 . 50 ft Weir Coefficient . . . : 9 . 739 height : 310 . 00 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-- ------- ---------------------------------------------------------------------------------------------- 308.50 0.0000 308.90 2.3919 309.40 3.5879 309.90 4.4749 308.50 0.0000 309.00 2.6743 309.50 3.7820 310.00 4.6320 308.60 0.3060 309.10 2.9295 309.60 3.9666 308.70 0.8711 309.20 3.1642 309.70 4.1430 308.80 1.6003 309.30 3.3827 309.80 4.3121 I ! �I , I f �� I • i--� J 10/1/O1 1 :23 : 6 pm Dodds Engineers, Incorporated page 6 RENTON MINI STORAGE CORE NO. 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- LEVEL POOL TABLE SUMMARY MATCH INFLAW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE . r--——-DESCRIPTION-—-----> (cfs) (cfs) --id- —id- <-STAGE> id (cfs) VOL (cf) 10 YEAR ...................... 0.00 4.�4 VAULT INF 308.45 1 0.76 16109.52 cf 25 YEAR ................ ...... 0.00 4.79 VALTLT COMBI 308.74 2 1.91 16676.30 cf � 100 YEAR ............... ...... 0.00 5.54 VAL7I,T COMBI 309.01 6 3.46 17220.23 cf . I � I i I � ,II I ' , I ' I I r__ , � �� � �- � , I t ' �' r' �� Earth Consultants Inc. u (���1�� � ��'�1�i ;���`��, ��i Geo�echnical Fngineers.Geologisis&6nvimnmental Scirntists March 29, 2001 E-8307-4 Revised May 25, 2001 Northward Properties 1560 - 140`'' Avenue Northeast, Suite 100 Believue, Washington 98006 , Attention: Mr. Patrick Giiroy Subject: Infiltration Testing and Slope Recommendations Renton Office and Mini Storage Northeast 3'� Street Renton, Washington References: Earth Consultants, Inc. Geotechnical Engineering Study E-8307-3 dated September 7, 1999 _ Earth Consultants, Inc. �, Geotechnical Engineering Study Update '�, E-8307-4 dated February 26, 2001 ' Dear Mr. Gilroy: In accordance with your request, we have prepared this letter to present the infiltration test results for the infiltration vault and permanent slope recommendations for the proposed Renton Office and Mini Storage development. We understand that it is planned to construct an infiltration vault at the north side of the proposed site with a footing elevation of 32.0 feet. - In our opinion the water infiltrated into the native soils at elevation 302 feet as proposed should infiltrated vertically based on the permeability of the native soils encountered and should not expose the existing soils to infiltrated water. If fill soils are encountered, the fill soils should be removed to native soils. 1805-136th Place N.E.,Suite 201, Bellevue,NJashington 980G5 6elle�����e 1425;643-378G FA.'r,:f�25;�46-48�C Tol:F�ee f8881?39-66'0 4.. � Northward Properties E-8307-4 March 29, 2001 Page 2 Revised May 25, 2001 Infiltration Recommendations Four test pits were excavated at the approximate locations shown on Plate 2. Please refer to the Test Pit Logs, Plates A2 through A5, for a more detailed description of the conditions encountered at each location explored. A description of the field exploration methods is included in Appendix A. The following is a generalized description of the subsurface conditions encountered. The fill in the vicinity of the vault varied in depth from four and one-half feet in test pits TP-101 and TP-102 to fifteen (15} feet deep in test pit TP-103. In general, the fill soils observed in the vicinity of the vault consist of silty sand with gravel and construction debris including asphalt, concrete, bricks, ashes, rebar, and wood debris (Unified Classification SM). The native soils underlying the fill consist of poorly graded sand with silt (SP-SM) to poorly graded gravel with sand (GP). No groundwater was observed in our test pits. The soils encountered in the test pits were not screened for contamination. There were traces of staining and some construction debris observed, however no significant signs of contamination s�ch as strong odors were encountered. Three infiltration tests were performed in general accordance with the EPA fatling head method described in the 1995 King County Storm Water Manual. The test locations are shown on the attached Test Pit Location Plan, Plate 2, and were approximately fifteen {15) feet below the existing grade. The tests were in the native soils underlying the fill. The measured rates were 46 inches per hour, 32 inches per hour, and 69 inches per hour in test pit TP-1, TP-2 and TP-3, respectively. Averaging the rates and dividing by two for the test method, the adjusted rate would be 24.5 inches per hour, which is in excess of the maximum rate of 20 inches per hour for the soils encountered. We recommend using 20 inches per hour for a design rate. The factors for clogging and geometry need to be applied to this rate. The proposed vault is located approximately one hundred fifty (150) feet from the top of the slope on the west side of_the project. We do not anticipate the infiltration vault will impact the slope. Our test pits indicate the depth of the silty sand fill increases west of the proposed vault. We anticipate the water infiltrated at the location of the proposed vault will travel vertically through the cleaner sand and gravel layers underlying the proposed vault not towards the slope. In our opinion the water infittrated into the native soils at elevation 302 feet_as proposed should infiltrate vertically based on the permeability of the native soils encountered and should not expose the existing soils to infiltrated water. Earth Consultants, Inc. Northward Properties E-8307-4 � March 29, 2001 Page 3 Revised May 25, 2001 Temporary Slope Recommendations - - - - — - - - - - - In no case should excavation slopes be greater than the limits specified in local, state and Federal safety regulations. Based on the information obtained from our field exploration and laboratory testing, the fill would be classified as Type C by OSHA. Temporary cuts greater than four feet in height in Type C soils should be sloped at an inclination of 1 .5H:1 V. The native soil would be classified as Type B by OSHA. In Type B soils temporary cuts greater than four feet in height can be steepened to 1 .5H:1 V. If slopes of this inclination, or flatter, cannot be constructed, temporary shoring may be necessary. Slopes in fiil soils may need to be inclined to 2H:1 V. Excavations should be monitored during grading operations so supplementa! recommendations can be provided if needed. Large pieces of construction debris such as concrete, asphalt, or wood may be encountered. Temporary slopes for the vault should be covered with 6-mil Visqueen as soon as the excavations are made to prevent water from falling on the slopes and running into the native soils. The visqueen should be left in place when the vault is backfilled to prevent water from seeping into the fill soils. Vault Retaining Walls The vault retaining walls should be designed to resist lateral earth p�essures imposed by the retained soils. Walls that are designed to yield can be designed to resist the lateral earth pressures imposed by an equivatent fluid with a unit weight of tF�irty five (35) pcf. !f walls are to be restrained at the top from free movement, the equivalent fluid weight should be increased to fifty (50) pcf. These values are based on horizontal backfil! and that surcharges due to backfill slopes, hydrostatic pressures, traffic, structural loads or other surcharge loads will not act on the wall. If such surcharges are to apply, they should be added to the above design lateral pressure. The passive pressure and friction coefficients previously provided in the foundation section of our referenced report should be used. Backfill for the vault should not be the existing fill soils but should be the native soils or imported structural fill. In order to reduce the potential for hydrostatic forces building up behind the walls, retaining walls should be backfilled with a suitabl� free-draining material e�ctending at least eighteen (18) inches behind the wall. The remainder of the backfill should consist of structural fill. The free-draining backfill should conform to the WSDOT specification for gravel backfill for walls {WSDOT 9-03.12{2)). A perforated drainpipe should be placed at the base of the wall and should be surrounded by a minimum of one cubic foot per lineal foot with three=eighths inch pea gravel. Earth Consultants, Inc. Northward Properties E-8307-4 March 29, 2001 Page 4 i Revised May 25, 2001 �' Siope Recommendations Three additional test pits were excavated along the ridge below the west slope. Please refer to the Test Pit Logs, Plates A5 through A7, for a more detailed description of the conditions encountered at each location explored. A description of the field exploration methods is included in Appendix A. The following is a generalized description of the subsurface conditions encountered. Test pits TP-104, TP-105, and TP-106 indicate a fill approximately seven to eighteen (18) feet deep. The fill soils consist of inedium dense silty sand with gravel and construction debris including asphalt pieces, concrete, brick, ashes, rebar and other metal pieces, plastic sheets, broken bottles, and wood debris iSM). Underlying the fill, we encountered poorly graded sand with silt and gravel (SP-SM). No groundwater was observed in the test pits. Permanent cut and reinforced fill slopes should be inclined no steeper than 1 .5H:1 V (Horizontal:Vertical). Recommendations for fill slopes were provided in our referenced Geotechnical Engineering Study Update. Cut and fill slopes should be observed by ECI during excavation and construction to verify that conditions are as anticipated. Water should not be allowed to flow uncontrolled over the top of the slopes. Permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficia! layer of soil. We appreciate the opportunity to be of service, if you have any questions or need additional information, please contact us. — Yours very truly, �p.��IF� "�~ pf' �'ASyJ.y �'� EARTH CONSULTANTS, INC. � �� � o R, � � x � (; -{�--� � _ � l C a--C-�i�`--�-' ��' t G / Rodney Dulla Palacios Kristr �o�gf� , . s��"!o / Staff Engineer Project � �E?CPlRES 02-�?9- 03 RDPiKMWijmp Attachments: Plate 1 Vicinity Map Plate 2 Test Pit Location Plan Appendix A Field Exploration Appendix B Laboratory Test Results Earth Consultants, Inc. - — i 't"� ,Yk .c� �� �if � �.:,, �a-�-�- -s,�'""_ _# c _ ..� �C`��t � u }y € W� 4F :,. . -,.._._._�_.�� ���� 4 � -� z f'`,,�,* y� ; ��s'� ,�_�.._ '�.. .e� _ •s � �}� 1 = ' ., ^�..�"""�N F . �1 � �.�F � 4 c$ �_= /`--s_�S . 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' ;'�r' � `� k ..y'.'s' .. ��. _ � _����-`_ _!- �;z���: I �.'�L 't 'r y` .;'6� � � ��� j � `� . . -i. '�� �' - . :�f. �' '•,}.$� 'f .sr't,t ` � `"-a , �3 {{ 3 � . 4 ��v �Y .{�f' Y�.�•- t�.j�5f? i i k'•� .. ,..._..,, ! � #,\ `6 f�_-� - ' v � +.�� i �ECC'ilY"€.- ;" {_ ., � t' . . tr<'.}� ' T+ � S ;� -+ »°� � ��+.3}i y�F3t z� � 3 � - i ,!,' . . .'��'r �' '., . Reterence: EaI"tYl COr1Sl.11tarltS, [rlC. Puget Sound Area Geotechnicai Engineers,Geologis�s 8 Envtronmenrai Scientisrs j King County/ Map 656 By Thomas Brothers Maps Vicinity Map Dated 2001 Renton Mini-Storage Renton, Washington NOTE: This plate may contain areas of color. ECI cannot be responsible for any subsequent Drwn. GLS Date Mar.2001 Proj. No. 8307-4 misinterpretation of the information resulting ; from black &white reproductions of this plate. Checked RDP Date 3/29/01 Plate 1 ! � - - � II ! III '— � (��� .. III �C`� � � Proposed ���� , Storm Drainage � Vauft ; � " _;_ 102'TP-1 qi� �TP-11 _��_ i� J, ; 32o Approximate Scale ; TP-107-i-}� 0 50 100 200ft. _:_ A 3t0 � P-14 300 -�- I FC�FNI7 TP-8 28� �TP-s TP-101 -i-Approximate Location of �o ECI Test Pit, Proj. No. TP-6 ; i G E-8307-4, Mar. 2001 TP-1 -�-Approximate Location of ECI Test Pit, Proj. No. E-8307-3, Sept. 1999 ------------ � , �-------------; F � B Subject Site ' �-, TP-� � � Proposed Building zso -:- � � �--:-+ i--- H �TP-106 i � 4'P-5� i i z_ ; � � � � �o �----i Proposed Future Addition � � , , � � � � , � � �_____, (Phase II) ' � i i i i � � � i i � i � i i i i � i:; i :, � t � r- � - ;_., � . � : -'- � � � 1 I TP�105 � < < �� � ' � -�.- i____ NOTE:This plate may contain areas of color. ECI canno# � i �'TP-1�� ____ be responsible for any subsequent misinterpretation of i i � � � � i -� P�� the information resulting from black& white reproductions �I � i i i � � E of this plate. ! i i i i � J � , � � -j- � ' i � ' TP-104 � ' � � ' Earth Copsultants, Inc. . � � � � Geofechniql Engjneers.Geologisls&Environmental Scientists � � � � � � � � � i ; ; � �T:-2 TP-3 - Test Pit Location Plan � � � ; � �---� '---- Renton Mini-Storage Renton, Washington ; �-------------� p � �--------------� Drvvn. G LS Date Mar. 2001 Proj. No. 8307-4 3'0 3� Checked RDP Date 3/30/01 Plate 2 260 270 280 290 300 i APPENDIX A FIELD EXPLORATION E-8307-4 Our fieid ex loration was erformed on March 14, 2001 . Subsurface conditions at the site �� I P p were explored by excavating seven test pits to a maximum depth of twenty-one (21) feet below the existing grade. The test pits were excavated by Northwest Excavating subcontracted to ECI, using a trackho� Approximate test pit locations were �cter�nine� k�y �ac�ny trorr� s�t� f�acures. Approximatt test pit elevations were dete�mined by locating on the site plan. The locations and elevation;: of the test pits should be considered accurate only to the degree implied by the method used. These approximate locations are shown on the Test Pit Location Plan, Plate 2. The field explorat+on was continuously monitored by a engineer from our firm who classified the soils encountered, maintained a log of each test pit, obtained representative samples, measured groundwater levels, and observed pertinent site features. Samples were visually classified in accordance with the Unified Soil Classification System, which is presented on Plate A1, Legend. Representative soil samples were placed in closed containers and returned to our laboratory for further examination and testing. Test Pit Logs are presented on Plates A2 through A8. The final logs represent our � interpretations of the field logs and the results of the laboratory tests of field samples. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. The consistency of the soil shown on the logs was estimated based on the effort required to excavate the soil, the stability of the trench walls, and other factors. Earth Consultants, Inc. MAJ4R DIVISIONS GRAPH LETTER TYPICAL DESCRIPTION �SYMBOL SYMBOL d � G�/ Well-Graded Gravels, Gravel-Sand Andve1 Clean Gravels 4 �� �Q • gw Mixtures, Little Or No Fines Gravelly (little or no fines) M M Gp Poorly-Graded Gfavels,Gravel- Coarse Soils • • � Grained � � � gp Sand Mixtures, Little Or No Fines Soils More Than GM Silty Gravels,Gravel-Sand- 50% Coarse Gravels With gm Silt MixWres Kraction Fines(appreciable Retained On amount of fines) CiC Clayey Gravels,Gravel-Sand- No.4 Sieve 9C Clay Mixtures Sand �o 00 ' SW Well-Graded Sands, Graveliy And Clean Sand � o �� o SW Sands, Little Or No Fines Sandy Ilittle or no fines) ::::i::;;:.:�:��:�..>:1�..: More Than Soils e � � O �r: SP Poorly-Graded Sands, Graveliy � 4�..;#.,; S Sands, Little Or No Fines Sp% Materiai __ ::.: ...... P Larger Than More Than SM No.200 Sieve �% Coarse Silty Sands, Sand- Silt Mixtures Size Sands With Sftl Fraction Fines(appreciable Passing No.4 amount oi fines) / SC Sieve SC Clayey Sands, Sand-Clay Mixtures '� � � ML Inorganic Silts 8 Very Fine Sands,Rock Flo�r,Siity- �p� Clayey Fine Sands;Clayey Silts w/Slight Plasticity Fine Silts �iquid Limit � CL �norganic Clays Of Low To Medium Plasticity, Gramed �d Less Than 50 � C� Gravelly Clays, Sandy Clays. Silty Clays, Lean Soils Clays � I � I � 1 QL Organic Silts And Organic I � I � I � O� Sitty Clays Of Low Plasticity MH Inorganic Silts, Micaceous Or Diatomaceous Fire More Tha� mh Sand Or Silty Soils 5096 Mater�al Silts Smaller T�an And Liquid Limit C�..� Inorganic Clays Of High No.200 Sieve Clays Greater Than 50 Cfl Plasticity, Fat Clays. Size ////j 0�"� Organic Clays Of Medium To High O�l Plastici[y, Organic Silts `t�� `��� `��� pT Peat, Humus, Swamp Soils Highly Organic Soi{a i, �v, ��i, �v pt With High Organic Contents Topsoil 'y�'y�'� Humus And Duff Layer F��� Hiyhly Variable Constituents The discussion in the text of this repoR is necessary for a proper understanding oi the nature of the material presented in the attached logs. DUAL SYMBOLS ere used t�indicate borderl(ne soil clessiRcation. .�. C TORVANE READING,tsf I 2'O.D.SPLIT SPOON SAMPLER qu PENETROMETER READING,tsf W MOISTURE,%dry weight � 24"I.D. RING OR SHELBY TUBE SAMPLER P SAMPLER PUSHED " SAMPLE NOT RECOVERED � WATER OBSERVATION WELL pcf DRY DENSITY,�bs.per cubic ft. LL LIQUID LIMIT,% Q DEPTH OF ENCOUNTERED GROUNDWATER PI PLASTIC INDEX DURING IXCAVATION � SUBSEG�UEP(T GROUNDWATER LEIIEL W/DATE � � Earth Consultants Inc. LEGEND � 1 ' J i� I4'U1lY�Y1K�lll:llb'IINl'.f�.IA��UbL�LSSIJI\'IfINMIk'111.1iJ1'1(]IILSIS Proj. No.8307- Date Mar. 2001 Plate A1 Test Pit Log ProJect Name: Sheet of Renton Mini-Storage 1 1 Job No. Logged by: Date: Test Pft No.: 8307-4 RDP 3/14/01 TP-101 Eucavation Contactor. Ground Surface Elevation: NW F�acavating 315' Notes: � o L d � o Surface Conc�tions: Grass General Notes (% � �, p " m � a � � � � SM Brown silty SAND with gravel, medium dense, moist(Fill) � 2 -construction debris, bricks,ashes,concrete pieces 8.5 3 4 '�"` 5 SP-SM Brown poorly graded SAND with silt and grav�el, medium dense, moist 'a o:° s 0 on � 0 e ° $ 0 9 e � O �O o a �� R o ° �2 a D � 13 0 � ° 14 ° ' �s _6°�fines at 16' 7.8 16 Test pit terminated at 16.0 feet below e�asting grade. No groundwater encountered during excavation. NOTE: Elevations obtained from Core Design Topographic Survey,dated � 10/2000, Project Number 99121 0 � U W � � � Test Pit Log c� Earth Consultants Inc. Renton Min�Storage O Gr,aecYmkalFnglrxe�s.Gc.�kigl.�n&F]�NrmnxrrAlXim/P.� Renton,Washington F- � W Proj.No. 8307-4 Dwn. GLS Date Mar. 2001 Chedced RDP Date 3/29/01 Plate A2 �-- Subsurface conditions depicted rep�esent our observations at the Gme and location of this e�bratory hole,modfied by engineering tests,analysis and judgmerrt_ They are r►ot necessarily re{xesenta6ve of other times and bcaGons.We cannot aocept responsibility for the use or interpretation by others of .,..,,,���,,.,...n�e..fe,+.,nµ,M�.,.. Test Pit Log ProJect Name: Sheet of Renton MinFStorage 1 1 Job No. Logged by: Date: Test Pit No.: 8307-4 RDP 3/14/01 TP-102 Excavation Contador: Ground Surtace Elevation: NW F�acavating 315' Notes: Surface Concfitions: Gfass General W a $ a .� a U $ Notes (°J6) � �n � � u> > cn SM Brown silty SAND, medium dense, moist(Fill) � 2 -construction debris, concrete,asphalt, bricks, ashes 3 4 4�9 �` `' SP-SM Brown poorly graded SAND with silt and grav+el, medium dense, moist >'o s 04 ;q s ° p 7 . b 00 8 0 9 � 0 o �p o ° 0 11 e ° 12 0 o ° 13 ' a o ° 14 .�1 . 15 GP Brown poorly graded GRAVEL with sand, medium dense to dense, • moist a.s �'� �s -2%fines Test pit terminated at 16.5 feet below e�asting grade. No groundwater encountered during excavation. Q � O (7 U W � a � � Test Pit Log � Earth Consultants Inc. Renton Min�Storage J Cn�aMmk.alFnpfie�-ns,Gmk�gt�:tskF.nvlmnnKnralXir.ntL�; Renton,Washington C a � Proj_No. 8307-4 Dwn. GLS Date Ma�.2001 Chedced RDP Date 3/29/O1 Plate A3 Subsurface oonditions depfcted represent our observations at the time and location of this e�loratory hole,modified by engineering tests,anal�rsis and judgmerrt. They are not necessarily represerrtative of other times and locations.We cannot accept resQonsibifity for tlie use or irrterpretation by others of :.,fnr..��1:.v..vncnnfc.�nn lhi�I.v. Test Pit Log Project Name: Sheet of Renton Mini-Storage 1 1 Job No. Logged by: Date: Test Ptt No.: 8307-4 RDP 3/14/01 TP-103 Excavation Contactor: Ground Surtace Elevation: NW E�acavating 315' Notes: „ L „ � o Surlace Conditions: Grass Generai $ Notes (qf,) La° �, p " ,�o � i, c7 rn cn �n SM Brown silty SAND, loose to medium dense, moist(Fill) � 2 -observed construction debris,concrete, asphalt, rebar, ashes, plastic 16.8 3 4 5 6 7 8 9 10 ' 11 , 12 13 I 14 s.o '' "'' 15 SP Gra oori raded SAND with ravel medium dense moist 4°�6 fines Test pit terminated at 15.5 feet below e�dsting grade. No groundwater encountered during e�acavation. s � � 0 � U W � a � � Test Pit Log � F,arth Consultants inc. Renton MinFStorage J Gc�+r.[Y�nfcal Fn�On�s,CmHo�ilsn k Fiwlmnmrn�al Sckeiilsr.; � Renton,Washington a W Praj.No. 8307-4 Dwn_ GLS Date Mar.2001 Chedced RDP Date 3/29/01 Plate A4 Subsurface concEtions depided represent our otservations at the time and location of this e�loratory hole,maified by engineering tests,analysis and �udgment. They are nat necessan'ly representative of otF►er times and locations.We cannot acoept responsibility for the use w interpretation by others of ..s......��v..,.,,ncn..��l...,µ,ic�.... Test Pit Log Pro)ect Name: Sheet oi Renton MinFStorage 1 1 Job No. Logged by: Date: Test Pit No.: 8307-4 RDP 3/14/01 TP-104 Ew�avation Contador. Ground Surtace Elevation: NW F�acavating 290' Notes: ���' W „ g �, � surtace conditions: Depth of Topsoil &Sod 1"-2":grass L d (n PIOteS �°b� C9 cn 0 � cn � u1 SM Gray silty SAND, loose to medium dense, moist(Fill) � � 2 -observed concrete, asphalt, bricks, plastic, broken glass,organic odor 20.� 3 4 5 25.4 6 7 8 -observed wood debris(small chunks) 9 10 11 12 -grades to a brown ashlike clastic sand with broken glass and ashes 39.3 13 14 15 � 16 � 17 0 � 6.6 �8 ' ; • �9 SP-SM Brown poorly graded SAND wfth silt, medium dense, moist Test pit terminated at 20.0 feet below e�osting grade. No groundwater � o° encountered during e�acavation. a 0 � Test Pit Log Earth Consultants Inc. Renton Mini-Storage � cx�r.ctmk-alFngtnexas.crc��isn�Fnv�mnnx�rxa��rnrt+r; Renton, Washington F- a � � Proj.No. 8307-4 Dvm. GLS Date Mar.2001 Chedced RDP Date 3/29/01 Plate A5 Subsurface condtions depided represent our observations at ihe time and location of this e�loratory hole,mocified by engineering tests,arratysis and i judgmerrt. They are not necessarity representative of other times and locations.We cannot accept responsibility for the use w irrterpretation by others of a.,s...,..��:.......�o..�e.+....�tiM u... __ _ @St It O9 Project Name: Sheet of Renton Mini-Storage 1 1 Job No. Logged by: Date: Test Pit No.: 8307-4 RDP 3/14/01 TP-105 Excavation CoMador. Ground Surface Elevation: NW E�acavating 290' Notes: „ — L „ � o surtace Conditions: Depth of Topsoil &Sod 1"-2":grass Generel W a g n « °- U � Notes ("�) c�7 cn � � � � �n SM Brown silty SAND, loose to medium dense, moist(Fili) � 2 concrete and some asphalt, red bricks, plastic, broken glass 21.6 3 4 -becomes gray 5 -45°k fines s � SP-SM Brown poorly graded SAND with silt, medium dense, moist ,:'c '' ; 0 8 :0 9 � 4.6 0 < 10 a a;. • �� O '' ' I� Test pit terminated at 11.5 feet below e�6sting grade. No groundwater ! encountered during ezcavation. Q � ' o I � U � W i e � Test Pit Log II t� Farth Consultants Inc. Renton Min�-Storage � O GcxHetiyinkalFYig/ne:eyn,Ge:olo�pst�RFnNronnxxn�at5clmtlsr.i Renton,Washington F � F W Proj.No. 8307-4 Dwn. GLS Date Mar.2001 Checked RDP Date 3/29/01 Piate A6 i Subsurface concfitiorts depicted represent our obse�vations at the time and location of this e�loratory hole,modfied by enflineering tests,analysis and I �udgment_ They are not necessariy representative of other times and locatans.We cannat acoe�t responsibility for the use or interpretation by others of .......��:.....,.�e..��...,K.:c i..., Test Pit Log Project Name: Sheet of Renton Mini-Storage 1 1 Job No. Logged by: Date: Test PR No.: 8307-4 RDP 3/14/01 TP-106 Excavation Contador. Ground Surface Elevation: NW E�acavating 295' Notes: „ o L �, N o surtace cor�icions: Depth of Topsoil&Sod 1"-2":grass and small trees General W Notes (%) � cn � � v> > cn SM Brown silty SAND with grawel, loose to medium dense, moist(Fill) � 2 -construction debris observed,small pieces of concrete,asphalt, bricks, plastic, broken glass, organic odor �s.s 3 -becomes reddish brown 4 5 6 7 -ashes observ�d s s �o 2.s •;a�a �� SP Grades to brown poorly graded SAND, medium dense, moist p e °Q 12 o,o<�;.'. :�...,,O�;.'.:' ,p ��:o:'�. 0 � <_o.Q:.> 13 .0:..:Q:_4:::� Test pit terminated at 13.5 feet below e�6sting grade. No groundwater encountered during e�aravation. Q � � � � U W � d � � Test Pit Log (� Earth Consultants Inc. Renton Mini-Storage O Gcxxectmk2lFngRxxcya.Cw�ok�gis�&FnvlmnnxMalScyr.ntb'n Renton, Washington � J I H a WProj.No. 8307-4 Dwn. GLS Date AAar.2001 Chedced RDP Date 3/29/01 Plate A7 Subsurface cond�tior�.s depicted represent our observations at the time and location o(this e�loratory hole,modfied by engineering tests,anatysls and � judgmerrt. They are not nece�arily represeMative of ather times and locations.We cannot acoept responsibility for the use or interpretation by others of �����������tiM iM Test Pit Log Project Name: Sheet of Renton Mini-Storage 1 2 Jab No. Logged by: Date: Test Pit No.: 8307-4 RDP 3/14/01 TP-107 Excavation Confador: Ground Surface Elevation: NW E�acavating 310' IVaes: � o � „ � o surrace condicions: Depth of Topsoil &Sod 2":grass and small trees G��I W �T � LL � � � (°'�) c� �n � cn � v� SM Dark brown to brown silty SAND with gravel, loose to medium dense, ' moist (Fill) ' � 2 -construction debris observed, pieces of concrete,rebar, bricks, broken glass,wood debris 9.9 3 4 5 -becomes gray 6 -asphalt chunks 1'-2'observed 7 14.3 8 -becomes gray with gravael 9 -23%fines �o >> 12 13 14 15 16 17 � 18 � 0 w 2�4 19 -observ�ed a yellow sandy soil, possiblyfoundry material � a � � Test Pit Log �7 Earth Consultants Inc. Renton Mini-Storage O cx�c.rtmk-alt]ignx.r�s,Gcx�k�tsts&�vlmnnxnralScYmn.s� Renton, Washington � a w Proj.ivo. 8307-4 Dwn. GLS Date Mar.2001 Chedced RDP Date 3/29/01 P�ate A8 Subsurtace cond'dions depicted rpr esent our observations at the time and location of this e�loratory hole,modfied by engineering tests,analysis and judgment. They are not necessaerily representative of other times and locations.We cannot accept responsibility for the use or interpretafan by others of ;..s.,.,..�,�.,.,...�..«�...,r►,;�i.,., � � � � � � � • •• • � � -� ' ; - . �� �����t.wii������������������������1���■������� � •. .l,- ����S:J�H�����������������������������r�� ������\��t��ti����������■����������■������� � �������L�������������������������������� •� �������►�o������������������������������ � �����■��\�Di����■������������������������ �������t11�a1 ���■������������������������ ��������\\� �����������������������■���� ���������� ������������������r��������� • ���������\�M ��������������������■■������ • � '' ��������■\\ �r�������������������������� � ����������i ��������������������������r� ■ ��������■�\ ��������������■������■������ • ������������!���■�����■����������■■������ � �����■���� �tl��������������■�����■■������ � � ���������� �.���■������������r���■�■����� • ���������� j��������������������■■������ �����■���� l�►7�������������������/������ � �����������ia������r�������������������� ,� ' �������r�� \������������������������■���� ��������■� \���� �����������������/■■�0�� ���������� ���!l�H������������������■������ • ■ ��rr�������1����0�\'_����������������■�■����� . � � �����■������r0■���r�������������■■■���r� � � ��������������l��71 ��������������■■■����� • �. ���������� �Vi���\���������������■�■����r �■����■�■�■���i i�rr��■�������■������������������ ��������������►�r�v��►���r������������������� . •� ��������■i������■■o�������������������■■����� , ��■������������■■���i�������������■�������� ' .. ���������������s��������������������■�■■���� ���������������■■��������■�������w������������■ ���������■i�r���r�������������������■������■ - ��■r��������r���i������■����������������� - ' �����������������■���`��,�����■����������■���� ' ��������■������■��■cv�����������������■���� ��������■����■��v:���■����������■���������� ��■�������� ����■��s�•�■������■�������■������� �����■��■�����\��i��������������■■�■���� � �����■���������������'����������/■■�■���� :� �����■����r��������[�������������■■������ �������l�����������\������������■■■����� ��������������������■\����������■������� ��������■�����������:7�� ��■������������� . � �������������������5!�Al�'1�'�������■������� � • �������������������ii��L._��!�������■�■����� � ��������������■r�����i'Y='�.�s■�����■■■■���� ������■��������������■��• a�������■������� , �■���■u■v���i��i��■ u■■�i�i�����■�u■�i■■������i�i'��■�u����■�������� �� - - � - - - - - - - - � � � - - - - � • ' �� � �I�L►L� . - � �-� ' , � � �� � �• '• mm ,• • � • . . " . . • • : • ��• _ . . - . � 1 � � � � • ' i • • • • • � -� � • • � 1 • � � � � � � � . • •• � � � . s 1� ����Sir/��7r�i ���������������������������� � •. ,/,' r�������r1► ��-���������������-��■■����� ������r��i. �I����■����������������■■����r� � ��������������■���rr�������rr��■�■■���� '� ��r������� �s�'��������������������������� � ����������i����\��������■���������■■■���� ������������7��O���r�������������■■■■���� ���������������\�����������������■■����� �����■������i i��������r�����■������■������ ��������r�����7���►����������������■������ � � ' � ������������������w����■���������■������ �������������������i�������������■■����r� � ����������r����i��\�������■�����■■������ • ����������������� �������������■������� � �����■���� ���■��r�\������������■�■■���r � ' ���������� ������i������������r��■■��r�� ��������■����������\�1�����������■■������ • ���������� ��������t��1�����������■������ ��������������■����\�\\����������■■������ � ���������� ���� ����l������������■������� •� ' ����r���������■�����\�\������������■■���� �����■�������������5\■�\���������■■���0�� �����■��������������1■�\��������■■■����� � . ��������������������ul�<rl'�������■������� �r������������������►������������■■������ � � � ���r������ �����������������������■����� � � •. ���������������������7�����������■������ ���������������������\��li 7�������■■■���� ���������� ���■�����■t�����������■��r��� � ,� ��������■�����■�������\���■������\������ .� ' ���������� ���■�����������������■�■����� .. ��������■� �����r���■����������■������� ���������� ����r��r��� ���������■■������ �����■�����������������:��������■■�■���� � � �������������������r■��\'��������■■����� � ���r����������������■��t��������■■■■���� ��������������■�����■�■�i��������■■■���� ���������������������������������■������ ��������������■���������[��1�������������� ��������������■��r����■��■�����■■������ • � ��������������■����������������■■������ .� ���������������r��rr������������������� �����■�r�t���������������A������������� ��������■����������������������r■������ ��������������������■����■��r�■�������� . � �r������������������������������■������ � � �����■��■5�������������������r�■■������ ��■���■��������■�������■�a�������■■�■����� ■����������������■����������������■■������� , ����■����������i�����■��i�i���■���u���■■���■�����■�i�������■�������■ �� - . - - - - - - - - � . . � •• � ���1'u��� . - • � ��� ' � � � �� � �- '� mm �. . . . ,: • � . ; • ' : � � OVERFLOW ANALYSIS An overflow system will be installed to convey flows exceeding the developed 10-year, 24-hour storm event. The overflow system will be a 12"tightlined storm drainage system that will connect to the existing 12"tightlined storm drainage system on NE 3rd Street. An overflow riser will be installed within the water quality/infiltration vault at an elevation equal to the elevation of the maximum water surface elevation for the 10-year, 24-hour storm event. The shallowest slope along the existing 12"is immediately downstream of the point of connection. This point of connection is the concentration point for the determination of the upstream area. See Section 2 Upstream Tributary Area for a description and e�ibit of the frontage upstream area tributary to the existing 12" conveyance system along NE 3rd Street. The existing pipe slope immediately downstream of the point of connection is 1.9%. Upon proving that the 12" storm drainage system can safely convey the required flows at the shallowest slope will ensure that the system can convey the required flows to a point where the site's 100-year, 24-hour peak flow will become an insignificant portion of the entire contributing basin. The impervious and pervious areas of the frontage upstream basin were determined by use of either Table 3.5.2B of the 1990 KCSW�M for single family lots or assuming total forested conditions for multifamily and/or commercial lots or assuming 80%impervious coverage for main roads. Soils within the upstream basin consist of Arents, Everett material (An} or Type A soils. See attached Upstream Basin Map. The single family residences which will include Jefferson Avenue NE take up an area of 1.1 acres. There are 5 single family lots which would calculated to be 5/1.1 =4.5 DU/AC. The impervious area associated with the single family houses is therefore 46°/a of the 1.10 acres or 0.51 acre. The remaining lots consist of apartment complexes and an ANUPM on 4.8 acres. These remaining lots were developed with detention systems. The ground coverage for the apartment complexes and AM/PM are therefore assumed to be pre-developed forested conditions. . The remaining basin or 5.9 acres, consists of roads. The impervious area associated with the remaining area is 80%*5.9 acres=4.72 acres. I � i The following information was used to create hydrographs in WaterWorks (also see attached printouts). UPSTREAI��1 TRIBUTARY Total Area= 11.8 acres AREA TO POINT OF CONNECTION GROLTND COVER AREA(acre) CN 2° Growth Forest 4.80 55 Lawn & Landscaping 1.77 68 Impervious 5.23 98 Time of concentration Assumed 10.00 min. Under Section 3A of this report, the 25-year overflow rate is I.15 cfs. See Hydrograph 3. The upstream 25-year peak flow is 3.58 cfs. See attached Basin Summary on the following pages. The combined 25-year peak flow is 3.59 cfs. See Hydrograph 5. The 100-year overflow rate is 2.70 cfs. See Hydrograph 7. The upstream 100-year peak flow is 4.29 cfs. See attached Basin Summary on the following pages. The combined 100- year peak flow is 5.28 cfs. See Hydrograph 9. The existing slope immediately downstream of the point of connection to the existing tightlined conveyance system on NE 3rd Street is 1.9%. At 1.9%, a 12" pipe is capable of conveying Q= 1.49/n*A*R�"*St�� = 1.49/0.012*(�14*1�}* (0.5/2)�'3*0.019`'� = 5.33 cfs. The 25-year and 100-year peak flows are contained within the existing conveyance system. In the event the stormwater flows exceed the capacity of the 12" storm line, water would overtop the frontage catch basin and flow safely within the curbline of NE 3`� Street, as allowed under Core Requirement 1. i � 3/29/O1 2 : 9 : 1 pm Dodds Engineers, Incorporated page 2 RENTON MINI STORAGE 99121 '� --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY i BASIN ID: UPS025 NAME: UPSTREAM 25 YEAR EVENT SBUH METHODOLOGY TOTAL AREA. . . . . . . : 11 . 80 Acres BASEFLOWS : 0 . 00 cfs R.AINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 6 . 57 Acres 5 .23 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 58 . 50 98 . 00 TC. . . . : 10 . 00 min 10 . 00 mzn ABSTRACTION COEFF: 0 .20 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0050 � impTcReach - Channel L:1700 . 00 kc :42 . 00 s : 0 . 0200 PEAK RATE: 3 . 58 cfs VOL: 1 . 62 Ac-ft TIME : 480 min BASIN ID: UPS100 NAME : UPSTREAM 100 YEAR EVENT SBUH METHODOLOGY TOTAL AREA. . . . . . . : 11 . 80 Acres BASEFLOWS : 0 . 00 cfs R.AINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 . 90 inches AREA. . : 6 . 57 Acres 5 .23 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 58 . 50 98 . 00 TC. . . . : 10 . 00 min 10 . 00 min ABSTRACTION COEFF: 0 .20 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0050 impTcReach - Channel L: 1700 . 00 kc :42 . 00 s : 0 . 0200 PEAK RATE: 4 .29 cfs VOL: 1 . 95 Ac-ft TTME : 480 min C. Water Quality Volume Calculations Dead storage within the�vater quality/infiltration vault will be used for mitigation of the stormwater to meet Special Requirement#5 of the 1990 King County Surface Water Design Manual. A biofiltration swale will not be installed per Core Requirement#3 as allowed by the City of Renton. According to the 1990 King County Surface Water Design Manual, the required volume for dead storage of the vault shall be equal to the water quality storm in the developed condition. The water quality storm is defined as a storm having a precipitation equal to 1/3 of the 2-year precipitation. The dead storage required for the vault is 11,168 ft3. See basin summary printout on the following pages. The vault will be designed with a depth of 5.6 feet with surface dimensions of 20 feet by 100 feet. The dead storage provided therefore will be 11,200 ft3 which exceeds the required minimum. 10/9/Ol 2 :40 : 50 pm Dodds Engineers, Incorporated page 1 RENTON MINI STORAGE CORE NO. 99121 --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: DEVWQ NAME: DEVELOPED WATER QUALITY EVENT SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 0 . 67 inches AREA. . : 0 . 60 Acres 6 . 40 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 TC. . . . . 5 . 60 min 5 . 60 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0200 TcReach - Channel L: 670 . 00 kc:42 . 00 s : 0 . 0050 impTcReach - Sheet L: 126 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0200 impTcReach - Channel L: 670 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE: 0 . 71 cfs VOL: 0 . 26 Ac-ft TIME : 480 min �t , tlOBC.�" ,�� � ' ,-� . � � ,__ � ; 4. CONVEYANCE SYSTEM ANALYSIS AND DESIGN: The conveyance system for the site was designed for both the 25-year, 24-hour storm and the 100-year, 24-hour storm. A conveyance sheet was generated for the 25-year and 100- year storms using the rational method to calculate flows for each area collected by each catch basin. The precipitation rates for the 25-year, 24-hour storm and the 100-year, 24- hour storm are 3.40 inches and 3.90 inches consecutively. The flows generated from the 25-year, 24-hour and 100-year, 24-hour storms were input into a backwater analysis spreadsheet to confirm adequate sizing. A weighted C value was used for each area collected by each catch basin. The average C value for the developed site is (0.6 AC*0.25 + 6.4 AC*0.90)/7.0 AC = 0.84. The backwater analysis was performed to ensure that during the 25-year design storm, the maximum water surface elevation in each structure did not exceed an elevation equal to 0.5' less the rim and during the 100-year design storm, the maximum water surface elevation did not exceed the rim. Exceedance of a rim would be allowed if the topography of the basin would allow the overflow to be conveyed to the next downstream catch basin or if the topography could ensure that ponding would not cause structural damage. During the 25-year,the headwater elevations did not exceed 0.5' less the rim. During the 100-year, the headwater elevation exceeded the rims in CB 16 and CB 17. The overflow from these catch basins will pond within the roadway and will not flood any adjacent buildings. ,-, . � ' � � . n �: �A � . �'' �r,*��>,I r .p r,.l ' c*����� �,� U f'1 �b� wW"}Pi�� .Sr�// �,•.,� �/ �'� �Y�� .,aSC¢.� � ; � �� ,�`, �..... .,..�r- �, ��; _ ...- ,,��� � a �� r ,» 1 n... 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I.. _ . �., �� � , , � �sr . _. . .. � �� ?i' . , ., , , . . . �,' i,� i rF,^, �TQ� G����A�:���>��'�TE� D��I�� ` LOCATION: KING COUNTY 20-EiR KAINI�ALL: 3.9 1NCliES JOB NAMG: Aegis SeICSrorage and Office JOB NUMBER: 99121 PREPARED BY: R.Stevens llESICN S'I'ORM: l00 YEAR >, ; _ .. t��RF�tF!¢'r.�,t, ���� �RL3HURF . <IlHP£8YFE1LIy�i �;? . 9'lM��OF � RA�fBA�.L...�:7.Rl8�17`AA.Y> .��:; ..7!tPE. :���.�YtP7u '� s Y[176 ����A4.[trnL���� iN.����h,[,. ... . 1'll'M:C.,t�t';1(;l'tY!it'�1111�tRY �:;;�. ..f•crF��:��c:.�te.�.i.. .�.�.��tc'a �.�:Ct3pfipl:C;:�1'1"F `���.AN4.4 � bi31t�GN� . .CON.C. it�'iC,N5lTY �i�Ptf3W ..:: lvt,�A2M114tl�S 1Yth,�titL�R� .Si.QPE 1;3CNG'tlE vy+�,i��c��t�.����. 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PAGE 1 _ _ .... __. _. ...... _ _ . . _ _ __ _ _ _._ _. ...... . _..._..... _ . ....._.. _.... ___... . .. ... >: ����� �:�����.�,���<::����`����:���`.�� ... . ...:. LOCATION: KING COUNTY 24-HR ftA1NFALL: 3.4 INCHF.S JO11 NAMI?: Ae�;is tiel(titora�c and Of'ticc JOI�NUMl3l?R: 99121 PRP,PARIsD RY: R.tilevens DESIGN STORM: 2$ YEAR _ _ _ n�c.xeti�ewr..�w < Mtt�s>Mr� iniYe�ur��us:> i�ntiaiiK wifnknt�, iic�uW�.U+v i�[E�E i�u��; ��ivu .�er[s:t� zt�a.vs.� P�4;�P�C1'����JNE]VIrCRX.:...... Pt{*k���:tiA:C�1Fi;kT�... r1ki;A ��.��CfYEK'F'VYY�'htT ;:��Ak�A :� SSkM<1F��.�� C1�NC. T14'C�:MCIT1' -.�: F'i.i}1#' :: n1.�MNIN(:'$ DIA1tilEtEFL �.SLUe� 1;N.rvGrRl ��'ELLJCtIt���.; ['FMtr �����. Q{t�'III;L,y Y(EUI,1) Q�iC'1'�1p�FUt,t;:]:.�:: FRn16f To ���. E�C'i�F97 C' �: ->:4� C) �. 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PAGE 1 _ ;:. . , _.: .. :; : � : .� <.: «;: <,: «.: ,: _..... . ........ '. , ....._ .... ._. _ . _ ,.. . :. JOB NAMh. Aeqie Self Srorage an�OfTice PREPARED BY R.STEVENS I JOB NUMfSER: 991.1 DESICN STORM: 25 YEAR ENTftANCE F,N'I'RANCF. EXiT OUTLET INLET APPROACH BEND JUNCTION PIYE Pll'E D7ANNING'S OUTLET INLET PIPE FLOW VELOCITY TAILWATE FRICTION HGL HEAD HEAD CONTROL COIV7'ROL VELOCITY HEAD HEAD HEADWATER � FROM TO FLUW LENGTH D1A. n ELEVATION ELEVATION AREA VELOCITY HEAD ELEVATION LOSS ELEVATION LOSS W55 ELEVATIUN ELEVATION HEAD LOSS LOSS ELEVATION CB CB (CFS) (FEE'1� (II� VALUE (FEE'n (FEE'i) (SQ F'1� (FT/SEC) (tEE'1� (FEE'1� (FEE1� (�EE11 (FEE'I) (FEE'1� (rEE'1� (FEE'I') (FEE'n (FEE7� (FEE'1� (N'EN:1) RIM EL � I vlt 1.7 9 1Z 0.012 307.50 .i07.77 0.79 2.21 0.08 309.00 0.02 309.02 OA2 0.08 309.11 0.00 0.02 O.OU O.UU 309.U9 3I2 �' 2 I 0,8 140 12 0.012 307.77 _OS.tii 0J9 1.05 U.u2 309.09 OA6 309.ti1 0.00 0.02 309.63 0.00 0.00 0.00 0.00 309.63 31Z.9 3 ? 0.2 59 12 0.012 308.61 308.96 OJ9 0.22 0.00 309.63 0.00 309.96 0.00 0.00 309.96 OAO UAO 0.UU O.UU 309.9b 31..5 � 19 IS 2.0 122 12 0.012 307.70 30R.43 OJ9 2.ti0 0.10 31�.11 034 310.45 0.02 0.10 310.57 0.00 0.00 0.00 0.00 310.57 312 ��. IS 6 5.7 85 IS 0.012 306.60 307.-15 1.23 4.63 0.33 309A7 0.56 310.03 0.07 0.33 310.43 0.00 U32 0.00 0.00 310,11 �11.8 '� 16 IS 3.6 95 12 0.012 307J0 308.37 OJ9 4,53 032 310.11 0.80 310.91 0.06 0.32 31129 0,00 0.05 0.00 0.00 31I.23 31235 �. 17 16 LS 62 12 0.012 30R37 308.8U OJ9 1.88 OAS 31 L23 OA9 3ll 32 0.01 U.OS 3ll31 Q00 0.04 0.00 0.00 311.35 3123 18 17 l.Z IZ7 12 0.012 308.80 309.70 OJ9 L52 0.04 311.35 0.1: 31L47 OAI 0.04 3ll.52 UAO UAO QUO 0.00 311.52 i133 12 7 1.2 143 t2 0.012 307.15 308A1 0.79 1.57 0.04 310.12 O.IA � 310.26 OAl 0.04 31031 0.00 0.02 0.00 0.00 i10.28 311.8 , 13 12 I.0 IU3 I2 0.012 308.01 308.63 0.79 1.21 0.02 310.28 0.06 310.35 0.00 0.02 310.37 0.00 0.01 0.00 OAO 31U37 3123 � 14 13 0.5 189 12 0.012 308.63 309.70 OJ9 Ob5 0.01 310.37 0.03 310J0 0.00 0.01 310.71 0.00 0.00 0.00 0.00 310J1 3133 '�� 4 vlt 4.8 94 18 0.012 304.80 30517 1,77 2J1 0.1] 309.00 0.17 309.17 0.02 0.11 30930 0.00 0.11 0.00 0.00 309.19 311? �', 5 4 4.8 160 18 0.012 305.27 306.�7 197 271 0.11 309.19 Q28 309.4"7 0.02 0.11 309.ti1 0.00 O.II 0.00 0.00 309.49 310.5 �� 6 5 a.S 56 18 0.012 3U6.07 306.35 1.77 2J1 0.11 309.49 0.10 309.59 0.02 0.11 309.73 0.00 016 O.UO OAO 30'�,47 312.r� , 7 6 3.2 60 12 OAl2 306.85 307.15 0.79 4,06 0.26 309.47 OA1 309.88 0.05 0.26 310.16 0.00 0.07 OAO 0.00 310.12 311.3 ', R 7 L6 100 t2 0.012 107.15 107.65 OJ9 2.08 0.07 310.12 0.18 31029 0.01 0.0� 31037 0,00 0.05 0.00 0.00 ;10.33 31?2 'I 9 8 1.4 100 12 O.OIZ 307.65 308.15 OJ9 1J4 0.05 31033 �� 0.12, 310.45 0.01 0.05 310.51 0.00 OA: 0.00 0.00 310.49 311.8 I 10 9 0.9 106 12 0.012 i0R.15 30R.6R OJ9 I.20 0.02 ;10.49 0.06 +10.55 0.00 0.02 310.58 D.00 0.00 0.00 0.00 310.57 312Z �I II 10 03 18G 12 0.012 308.G8 309.80 UJ9 U43 0.00 310.57 0.01 310.80 O.UU UAU 31U.80 Q00 0.00 0.00 0.00 i10.R0 3133 , 10/VO l DODDS ENGINEERS,INC. PAGE I ;: ,, > ,:. c; �s� ;;. ; ;,, ;i'. :<. �::. . ::. .;,: Br1G '...nk"F JAT.�.6�i . .-.. ,:. .. �.� .� ......::::. . ....._,-: . ...�� ::. . .�::> ,::: ..,. .,.�.� .. ,�::.. ::.� JO[3 N 1�IF:: �1e�is Sclf tiiuro-i��•:md Otficc�. �.:: �PRIPARED BY: R.til'b;VN:Nti I JOf3 NUSII3ER: '�9121 DtiSIGN STORM: 1D0 YEAR EN7'RANCF. ENTRANCE EXIT OUTLET INLE1' AYPROACH AF.ND JUNf.TION PIPE PIPE MANNING'S OUTLET INLET PIPE �LOW VELOCITY TAILWATE FRICTION HGL N�AD HEAD CONTROL CONTROL VELOCITY HEAll HEAD HEADWATER FROM TO FLOW LENGTH DIA. n ELEVA'PION ELF.VATiON AREA VELOCTTY HEAD ELEVATION LOSS ELEVATION LOS9 WSS ELEVA'fiON ELEVATION IiEAD LOSS LUSS ELBVA'TION CB CB (CFS) (FEE1) QN) VALUE (FEE'I) (H'EN:1') (SQ N'T) (FT/SE(� (FF,E7) (FEET1 (CEC'1� (FEE'I� (FEE'1) (FEE'I) (FEN:I� (NEN;T) (FEE'11 (�'EE'I� (FEET) (FEE't) RIM EL 1 vit 2,1 9 12 0.012 307.50 307.77 U.79 ?.G2 0.11 3025D 0.03 309.53 OA2 0.11 309.65 U.UO C1.02 0.00 0.00 309.63 31Z I I.0 130 12 O.OI? 307.77 308.61 OJ9 1.24 0.U2 301.G3 0.09 309,72 0.00 0.02 309JS OAO ano 0.00 0,00 309.74 312.9 3 2 0.2 59 l2 0.012 308.61 30R.96 OJ9 015 0.00 309.�4 0.00 309.96 OAU OAO 30996 0.�0 0.00 0.00 0.00 3099G 312.5 19 IS 2.4 122 12 0.012 307J0 308.43 OJ9 3.Uti 0.15 311.00 0.47 311.47 0.03 0.15 311.65 0.00 O.OQ 0.00 0.00 3I1.65 312 IS 6 fiJ AS 15 0.01: 306.60 307A5 IZ3 5.48 U.47 310.11 0.78 310.R9 0.09 0.47 311.45 0.00 0.45 O.uO 0.00 311.00 311.8 16 IS 41 95 12 n.niz 307.70 lOR.37 0.79 5.35 0.45 3ll.00 1.12 312.12 0.09 0.45 112.ti5 0.00 0.08 U.UO IL00 31258 312.35 17 16 IJ 62 12 0.012 30R37 lOd.30 0.79 222 0.08 312.58 0.13 312.70 0.02 OAN 312.N0 D.00 0.05 0.00 0.00 3I2.75 31ZJ 18 17 1.4 127 12 0.012 308.80 30y.70 0.79 1.79 0.05 312.75 0.17 ?1291 0.01 01)5 312.97 0.00 0.00 0.00 0.00 312.97 3133 12 7 t.S 143 12 0.012 307.15 308A1 0.79 L86 0.05 311.03 01U 311.2? 0.01 0.05 31L29 Q�0 0.03 0.00 0.00 ill2ti 311.8 13 12 I,I I03 12 0.012 3089t 308.ti3 OJ9 IA4 0.03 31126 OA9 31135 OA1 0.03 311.39 0.00 0.01 0.00 O.UO 31138 1t2.3 14 13 0.G 189 l2 O.OI2 308.ti3 309J0 OJ9 0.77 0.01 31138 0.05 311.42 QUO fL01 31 L44 O.DO 0.00 0.00 QOU 311.44 3I33 4 vlt SS 94 lx o.012 304.80 ;05.27 1.77 3.1, 0.15 309.50 012 309.72 0.03 0.15 30990 u.0u O.tS 0.00 0.00 309.75 311.2 5 4 5.5 160 1R 0.012 3(15.27 30GA7 177 3.13 0.15 309J5 0.38 310.13 0.03 0.15 31031 0.00 0.15 0.00 0.00 310.16 310.5 G 5 5.5 56 18 0.012 306.07 306.35 1 J7 3.13 0.15 310.16 0.13 310.2'� n.n3 0.15 310.47 0.00 0.36 0.00 0.00 310.i 1 1126 7 ti 3.8 60 12 0.012 306.85 307.15 OJ9 4.84 U36 310.II 0.58 310.C,8 n.n� 036 311.12 0.00 0.10 U.W 0.00 311.03 311.8 8 7 1.9 100 12 0.012 107.15 307.65 OJ9 2.47 O.10 31 LU3 0.25 31118 0.02 0.10 311.39 0.00 0.07 OAO U.UO 31132 1122 9 8 1.6 100 IZ 0.012 307.65 308.15 U.79 2.U7 O.Q7 11I32 D.IR 311.50 0.01 0.07 311.58 Q00 0.03 0.00 0.00 311.55 311.8 10 9 I.l I06 l2 0.012 308.15 308.68 OJ9 1.42 0.03 311.55 0.09 31 LbA 0.01 0.03 311.67 0.00 OAO 0.00 0.00 31 I.A7 J 12.2 II 10 0.4 186 l2 O.OI2 30fl.68 309.80 OJ9 0.51 0.00 311.67 O.U2 311.69 0,00 0.00 911.70 0.00 0.00 0.00 OAO 311,'70 R11.3 10/I/Ol DODDS ENGINEERS,INC. PAGE 1 5. EROSION/SEDIMENTATION ANALYSIS AND DESIGN: The intent of this erosion and sedimentation control plan is to minimize erosion and the li transport of construction related sediments off=site. I I The following ESC measures are incorporated into the Erosion Control design: l. Clearing Limits: Clearing limits have been delineated on sheet C2.01 of the clearing , and grading plans. The clearing limits extend only to those areas that will be ' disturbed during construction of the subject project. In general, clearing limits extend around the subject property. 2. Cover Measures: The temporary erosion and sedimentation control notes listed on sheet C2.31 specify specific times at which temporary and permanent cover measures will be installed. 3. Perimeter Protection: Per sheet C2.01, silt fence will be used for perimeter protection. '� Silt fence will be installed along the perimeters of those areas that will be receiving I� silt-laden runoff. '� 4. Traffic Area Stabilization: A construction entrance will be installed at the entrance to ' the project site. See sheets C2.01 and C2.31 for location of construction entrance I and detail. � 5. Sediment Retention: The detention/water quality vault will be used for sediment I, retention. Sediment retention�vill be designed per the 1990 KCSWDM ', Sediment Pond Calculations The runoff tributary to the sediment pond was calculated using WaterWorks � hydrology software utilizing SBUH methodology. The soils on site consist of Arents, Everett material (An) and Gravel Pit according to the King County Soil Survey. See Section 2 of this report. According to the geotechnical consultant, the site has a large amount of fill atop the existing infiltrating soils. The site will therefore be considered to have pervious soils exhibiting characteristics of Type C soils. The precipitation rates used for this analysis are as follo���s: 2-year, 24-holir storm —� ?.00 in. —used for sediment pond sizin� 2-year, 24-hour stornl � 290 in. —used for riser sizing During the erosion control phase of the project, the site will be entirely cleared and will therefore be modeled as bare ground. The following information was used to create the runoff hydrograph from Waterworks: EROSION CONTROL PHASE Total Area= 7.6 acres GROUND COVER AREA(acre) CN Bare Ground 7.6 87 Time of concentration Assumed 10.00 min. The resulting hydrographs are: 2yr= 1.33 cfs l0yr=2.65 cfs Surface Area: SA= 2080 sf/cfs * QZ QZ = 1.33 cfs SA=2080 sf/cfs * 1.33 cfs= 2,766.4 SF The designed sediment pond is 78' x 36' at the standpipe overflow elevation SA=2,808 SF>2,766 SF� OK Pond Geometrv: 2:1 interior side slopes 3.5' depth The top of the sediment storage is EL 307.5. The elevation of the top of the ' standpipe is EL 311.0 (3.5 feet of depth). The bottom of the pond is 306.5 (1 foot of sediment storage). • Riser Pipe Design Flow=Q�o =2.65 cfs The flow capacity for an 18"diameter riser��vith 1 foot of head is approx B.Scfs»2.65 required. • Emergency Overflow Spillway Design Flow=Q��=4.23 cfs ; H =0.4' L = (Q1�/3.21H3�z))-(2.4HZ) _(4.23/0.812) —(0..384) = 4.82 The overflow spill�;-ay sho�vn on the plans is 6 feet���ide>4.8 required. • De��vatering Orifice: Orifice area=AS(2h)°�i/(10.6)(3600)Tg°�� � _ (2,808)(2)(3.5)0.'/(10.6)(3600)(24)(322)°' = 0.00202 sf Orifice diameter= 24(orifice areal�r)°' =24(0.00202/�)os = 0.609 inch. USE 1 inch min. �