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SWP272056
SAvV Fok F(LE - P4 ,BORONER SNORT PL A T SfIPL- 06/- W CO1VVEY,4NCE CALCUL AT/OVS IL y *. BY.- ✓OHN R. NEWeU INC. P.S P 0• BCX 3qG REN TON, WA q8O S 7 (20(o) ZSS- Z/9U BOA.' IVe2 PIPE FLOW CALCUL6710" ` _ REF, TL/PE / CP,-41N/1GE L-42 '/ -)TFii/AIZD f=?r PIPE,-) TO (3E C'OtIC l -IMOOTtl W4LL D,FsIGN Fog 25 ye EVENT CIZ17'6:2/A FUZZ DC,16N — k1f16 L O , 199 U PVOIZAUcic.5 'PATtotl,iC A-IFTfIOD RAINFALL 2,5 yQ / Z4 H2 p=3, 4- /Oo y/z /Z4 r/,C p= 3.q A = 11, 4 Z Ac L = 2/00, FaQ TC ) 5 = 9, Z% Fog TCf 1 V C CHA(4,r 4, 3, 3, e)) TL-&) = zlool(Z,31(LJ) = /`7Z Mlhr EXITING DGf = 5 L bla Q TO (EAsT ('Ul-V) = (//, 4z)(,26 0.54) / FS F20t 1 C HAI?T 4, 3,S.C Pca/O= I,32 oa Nw Z Fo2 /z 0 - L.fG TCe} 88% FOP TCt) L, 5 E 0,3 `liN. M/N/fl t/ Q( WEB"; CLtL✓i ( 7, 7 [4 o,6s- C Ct1AR r 4, c) HW- 0,6S ' oL T_P"I- ca / To C5 " 2 A= //, 4Z * Z,/? - /3• � % A� (,/i,aZ)(,:U) �- i' 0, zz t 1 IN of 2t--c ,,,i ro T(E) W ���Lv ErZr-S 4CCb2 -CB/} = (1, 54)(13,59)(,Zz) = �,GD CFS /Z , c C 1,44g11/v CF5 4-'7/ CFs 4&0 cF-S CP# Z Tu qL_TLE-T_ A 2FA C e " ' _ (30)(144)/43 5; 0 = 0,10 AC, TDTNC_ A17FA G (,.76) f /3-57(,22)) 0,ZZ3Z 7r�> _ lam• Z t l4�/�,IZX�o = rS,S� r �(c8- 70 ou7) = (i3'ro9J(,22)C ISZ� 4-58 C Fs IZ coat �Rr) = 4-7/ CGS > 4,56 CF-S, O!G U(F) = 4.7 7es : 6,00'/s VA = (G,00)(,lz)= Co,7Z'IL ('ACC, /Uo \10 FCvws U5e TIME = /5,2 HiM L`ONSEOVA710F I Ty 0U cC-7 b lo= (40998)(3,,?)= 1,d3 Q- 51 Cfs CE2 T ce / a :.- 9,47 CFs USE THESE VALUES IN �iCE' GU�+7� 2 AI�G�L`/515 - (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (I1) (12) (13) (14) (15) (16) (17) (ld) (19) (20) M Z Bar Fric- Entr Entr Exit Outlt Inlet Appr Hend Junc A Q Pipe Outlt Inlet Barrel 8arr1 Vel TW tion HGL Head Head Contr Contr Vel Head Head HW �++ Segment A Lngth Pipe "n" Elev Elev Area Vel Head Elev Loss Elev Loss Loss Elev Elev Head Loss Loss Elev A O n CB to CS (ofs) (ft) Size Value (ft) (ft) (sgft) (fps) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft) p S O � P C FalZ" a.ot4 0 i ;0� 2D 0,^g5 7,OZ l�,_ 1� �� 0 JOZA �� =� = 104.7Z �0?. -3 — — ;o_� Z => t c)Z, .a < v1 I^ 3,J1l � I,p�,')d �. !��-�� I-�i — ✓a�� „�,) 4= n > > -� y c � " r Z � � Q -7 -j 2 O = S z V' c N � O tt m m �o v — Q _ z > Z c r 0 1 4c' Values The allowable runoff coefficients to be used In this method are shown in Table 4.3.3A by type of land cover. These values were selected following a review of the values previously acceptable for use in the Rational Method in King County and as described in several engineering handbooks. The values for single family residential areas were computed as composite values (as illustrated below) based on the estimated percentage of coverage by roads, roofs, yards and unimproved areas for each density. For drainage basins containing several land cover types, the following formula may be used to compute a composite runoff coefficient "C�". C, = ((C, x A,) + (CzxA,)+... + (C„xA,J)/A, where: A, = total area (acres) A,�n = areas of land cover types (acres) C,,2„ = runoff coefficients for each area land cover type TABLE 4.3.3A RUNOFF COEFFICIENTS - "C' VALUES FOR THE RATIONAL METHOD* GENERAL LAND COVERS LAND COVER Q LAND COVER St Dense forest 0.10 Playgrounds 0.30 Light forest 0.15 Gravel areas 0.80 Pasture 0.20 Pavement and roofs 0.90 Lawns 0.25 Open water (pond, 1.00 takes, wetlands) SINGLE FAMILY RESIDENTIAL AREAS (Density is in dwelling units per gross acreage (DU/GA)) LAND COVER LAND COVER DENSI DENSITYSt 0.20 DU/GA (1 unit per 5 ac.) 0.17 3.00 DU/GA 0.42 0.40 DU/GA (1 unit per 2.5 ac.) 0.20 3.50 DU/GA 0.45 0.80 DU/GA (1 unit per 1.25 ac.) 0.27 4.00 DU/GA 0.48 1.00 DU/GA 0.30 4.50 DU/GA 0.51 1.50 DU/GA 0.33 5.00 DU/GA 0.54 2.00 DU/GA 0.36 5.50 DU/GA 0.57 2.50 DU/GA 0.39 6.00 DU/GA 0•60 For land covers not listed above, an area-weighted "C x At" sum should be computed based on the following equation: C x A, = (C,xA,) + (CzxA,) + ...+(C„xA,), where A, = (A, + Az + ...+Aj, the total drainage basin area. (For use only in determining peak design flow for analyzing and sizing pipes, culverts or channels) 43.3-2 1/90 "Ia" Peak Rainfall Intensity The peak rainfall Intensity (IF) for the specified return frequency U design storm Is determined using a unit peak rainfall Intensity factor (Q for a given return frequency (R) design storm using the following equation: IR = (PR)(IR) whgre: PR = is the total precipitation at the project site for the 24-hour duration design storm event for the given return frequency (from the Isopluvial Maps in Figures 3.5.1C through 3.5.1 H) iR = (aR \'c/ (bR) ; the unit peak rainfall intensity factor Where TC = time of concentration (minutes), calculated using the method described below only (T, minimum value Is 6.3 minutes) aR and bR are coefficients (from Table 4.3.3B) used to adjust the equation for the design storm return frequency U This "IR" equation was developed by SWM Division staff from equations originally developed by Ron Mayo, P.E.. It is based on the original Renton/Seattle Intensity/Duration/Frequency (I.D.F.) curves. Rather than requiring a family of curves for various locations in King County this equation adjusts proportionally the Renton/Seattle I.D.F. curve data by using the 24-hour duration total precipitation Isopluvial maps. This adjustment is based on the assumption that the localized geo-climatic conditions that control the total volume of precipitation at a specific location also control the peak intensities proportionally. I Figure 4.3.3A has been included to demonstrate that this unit peak rainfall intensity (IR) will generate a curve with the same characteristics as the historic 25 year I.D.F. curve. Note, T, must not be less than 6.3 minutes or greater than 100 minutes. On the historic I.D.F. curves the lower limit was set at 5 minutes, 6.3 minutes was selected based on the mathematical limits of the equation coefficients. TABLE 4.3.3B COEFFICIENTS FOR THE RATIONAL METHOD "ip" -EQUATION DESIGN STORM RETURN FREQUENCY (YEARS) aR bR 2 Year 1.58 0.58 5 Year 2.33 0.63 10 Year 2.44 0.64 25 Year 2.66 0.65 50 Year 2.75 0.65 100 Year 2.61 0.63 4.3.3-3 1/90 FIGURE 4.33A RATIONAL METHOD UNIT PEAK RAINFALL INTENSITY(25 YEAR STORM) 0 0 rn o rn u-s 0 u� r�• 0 r-� tO 0 LO ors G � U-7 N d to � ,d. C u U7 t•'3 O r� CV O CV u7 • O 6.3 Minutes Minimum U-5 0 o O o 0 0 0 0 o O o Cr! DO lf3 N O O O O O O O O O O O iza (inches%hour) For basins with T, longer than 100 minutes use the Hydrograph Analysis Method to obtain UA _. . . (See Section 3.5) 4.3.34 1/90 FIGURE 4.3.3B AVERAGE VELOCITIES FOR ESTIMATING TRAVEL TIME FOR OVERLAND FLOW* *For use with the Rational Method only; From SoU Conservation Service,Tech.Release No.SS,January 197S O Ln O O O 0 —O 0 n (o Ln it M N .- O to 11� Ci N 00000 0 O O O O O 00 O 0 0 000000 0 0 0 0 00 N N ! i i i# i ! i # # ! ':• � I i II � I 1 # I } O `........... ............. .......... f.......................... t.. . t........ . tt.. ....... "t.... ......: .... ....» .............. ......... MO,y .. .... .... ...... ..... ...�. ...?....... . ...... ............. �.... T. }............t ............;.; ; °�iey .. ..... .... ......:... _ _... ......1. s.. ! : p�'Oi :.. ..,. .t.f.... °s N a/ead !cl M .............}............ .. I �S/ ! # � i r� do: � i + i • 1 � T .............#......_........ i.t.. . t. ::. .... ..... ........,............t....... ....l.... . ..t.. ... ... wjv��. ... ............ ................... 9v .,..;. ;.. .............. #.. ... _.1........._............................ (... I Ln q ... ..l... .... ...... ................................................. .. . .i .. ,�... .. ... . ' ...... ............. �? I ...... .. ... ..... . ..... M Ci Ci I i I O t I — i ! O O O O O Om co n w N Q M N �O �n M N �00 O O O O O O O O 00 0 0 oocoo 0 0 0 0 0 O (N/4)edolS asinowaleM 4.35-6 1/90 4 t 1 KING CUUN4" T, wAanitvu , %JA% mow - FIGURE 4.3.4D BACKWATER CALCULATION SHEET NOTES Column(1) - Design flow to be conveyed by pipe segment. Column(2) -Length of pipe segment. Column(3) -Pipe Size;Indicate pipe diameter or span x rise. mn Colu (4) -Manning'a'n'value. Column(5) •Outlet Elevation of pipe segment. Column(6) -trial Elevation of pipe segment. Coltunn(7) -Barrel Area Is the full cross sectional area of the pipe. Column(8) -Barrel Velocity Is the full velocity in the pipe as determined by: V - 0/A or Col.(8) - Col.(1)/Col.(7) • Column(9) -Barrel Velocity Head - V 12g or (Col.(8))'/2g Where, g - 32.2 ft/sec= (acceleration due to gravity) • Column(10)-Tailwater(TW)Elevation;this Is the water surface elevation at the outlet of the pipe segment. If the pipe's outlet Is not submerged by the TW and the TW depth Is less than(D+d j/2,set the TW elevation equal to(D+dj/2 to keep the analysis simple and still obtain reasonable results(D - pipe barrel height and d. - critical depth,both in ft. See Figure 4.3.51-1 for determination of dj. Column(11)- Friction Loss - S,x L or S,x Coi.(2) Where,S,is the friction slope or head loss per lineal foot of pipe as determined by Manning's Equation expressed In the form: S, - (nV)a/2.22 R"a Column(12)- Hydraulic Grade Una(HGL) Elevation just Inside the entrance of the pipe barrel;this is determined by adding the friction loss to the TW elevation: Col.(12) - Col.(11) + Col.(10) If this elevation fails below the pipe's Inlet crown,It no longer represents the true HGL when computed In this manner. The true HGL will fall somewhere between the pipe's crown and either normal flow depth or critical flow depth,which ever Is greater. To keep the analysis simple and still obtain reasonable results(ie,erring on the conservative side),set the HGL elevation equal to the crown elevation. Column(13)- Entrance Head Loss - K.x V'/2g or K.x Col.(9)Where, K. - Entrance Loss Coefficient(from fable 4.3.5A) TNs is the head lost due to flow contractions at the pipe entrance. r Column(14)- Exit Head Loss - 1.0 x V2/2g or 1.0 x Col.(9) This is the velocity head lost or transferred downstream. Column(15)-Outlet Control Elevation - Col.(12) + Col.(13) + Col.(14) This is the maximum headwater elevation assuming the pipe's barrel and Inlet/outlet characteristics are controlling capacity. It does not include structure losses or approach velocity considerations. Column(16)- Inlet Control Elevation(See Section 4.3.5 for computation of Inlet control on culverts). This Is the maximum headwater elevation assuming the pipe's inlet is controlling capacity. It does not include structure losses or approach velocity considerations. Column(17)-Approach Velocity Head;this is the amount of head/energy being supplied by the discharge from an upstream pipe or channel section,which serves to reduce the headwater elevation. If the discharge is from a pipe,the approach velocity head is equal to the barrel velocity head computed for the upstream pipe. if the upstream pipe outlet Is significantly higher In elevation(as in a drop manhole)or lower in elevation such that its discharge energy would be dissipated,an approach velocity head of zero should be assumed. Column(16)- Bend Head Loss - Kp x Va/2g or Ko x Col.(17) Where, V.. - Bend Loss Coefficient(from Figure 4.3.4E) This is the loss of head/energy required to change direction of flow In an access structure. Column(19)-Junction Head Loss;this is the loss In head/energy which results from the turbulence created when two or more streams are merged Into one within the access stricture. Figure 4.3.4F can be used to determine this loss or it can be computed using the fotlowing equations derived from Figure 4.3.4F: Junction Head Loss - V,x V'/2g or I(t x Col.(17) Where, I(t is the Junction Loss Coefficient determined by: K (Oa/0,)/(1.18 + 0.63(0a/0,)) Column(20)-Headwater(HW)Elevation;this Is determined by combining the energy heads In Columns 17, 18. and 19 with the highest control elevation in either Column 15 or 16,as follows: Col.(20) Col.(15 or 16) -Col-(17) + C01.(18) + Col.(19) 4.3.4-21 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 4.3.5E ENTRANCE LOSS COEFFICIENTS Type of Structure and Design of Entrance Coefficient K. Piro concrete PVC SRlral Rib D I and CPEP- Smooth Interior_ Projecting from fill, socket (bell) end 0.2 Projecting from fill, square cut end 0.5 Headwall or headwall and wingwalls Socket end of pipe (groove-end) 0.2 Square-edge 0.5 Rounded (radius = 1/12D) 0.2 Mitered to conform to fill slope 0.7 End-Section conforming to fill slope* 0.5 Beveled edges, 33.7* or 45* bevels 0.2 Side- or slope-tapered inlet 0.2 Pipe, or Pipe-Arch. Corrugated Metal and Other Non-Concrete or D.I. Projecting from fill (no headwall) 0.9 Headwall or headwall and wingwalls square-edge 0.5 Mitered to conform to fill slope, paved or unpaved slope 0.7 End-Section conforming to fill slope* 0.5 Beveled edges, 33.7° pr 45* bevels 0.2 Side- or slope-tapered inlet 0.2 Box Reinforced Concrete Headwall parallel to embankment (no wingwalls) Square-edged on 3 edges 0.5 Rounded on 3 edges to radius of 1/12 barrel dimension, 0.2 or beveled edges on 3 sides Wingwalls at 300 to 750 to barrel Square-edged at crown 0.4 Crown edge rounded to radius of 1/12 barrel dimension, 0.2 or beveled top edge Wingwall at 100 to 250 to barrel Square-edged at crown 0.5 Wingwalls parallel (extension of sides) Square-edged at crown 0. Side- or slope-tapered inlet 0.22 *Note: "End Section conforming to fill slope," made of either metal or concrete, are the sections commonly available from manufacturers. From limited hydraulic tests they are equivalent in operation to a headwall in both inlet and outlet control. Some end sections incorporating a closed taper in their design have a superior hydraulic performance. 4.3.5-9 1/90 , K I N G C O U N 'I' Y, W A J ri 1 IN U , U 11, %3 %+ FIGURE 4.3.SC HEADWATER DEPTH FOR SMOOTH INTERIOR PIPE CULVERTS WITH INLET CONTROL teo lo,000 16s 8.000 EXAMPLE (2) (3)6. ENTRANCE TYPE - 6,000 0.42 inch.. (3.5 foal) 6. 156 a.H2O G1e SQUARE EDGE WITH 144 • 5,000 5' HEADWALL 6. 5. 4,000 nw' Hw 132 • D feet 4 - 3.000 5. 4. 11) 2.5 8.d , 120 121 2.1 ,.• 1 �� - 2,000 a.- (3) 2.2 7.7 3 1 i too 3. - 3. PLAN ) 96 1.000 GROOVE END WITH 800 _ ._. . . HEADWALL 84 - 600 t 500 1 i 400 t N 72 p�•�%� 2 � � W 300 }'M.� 1.5 L5 x t i' / N. Z 60 U. 200 ►w- 1.5 _ PLAN l2� i Z w GROOVEEND 0 54 - a PROJECTING a o too z j48 / � 80 x / a a U /42 u 60 W o c 50 HW SCALE ENTRANCE cr _ 1.0 40 D TYPE W .9 9 f- ►t-- 36 30 U) sgeare edge ■ith 3 .9 1s1 headaoll Q - 33 a Q — 20 121 Groove and•�u W to Maaull = 8 .8 30 .8 131 Groove and plolaclieg 27 10 24 8 T 6 To use Scale (2)Of 15) Plate" 5 horisontellt to scale Ill.thsa 21 4 use straight inclinod line through D and D ►calls,or reverse so .6 6 3 i1luNrelad. IB 2 15 .5 5 .5 1.0 + t2 4.3.5-11 1/90 1° ADDITION TO LEVEL I DRAINAGE ANALYSIS �'- FILE NUMBER: 907-054. 00 BRETT BORDNER IS �► CIO •o � ins � SrONAL Ftl EXPIRES Q ADDITION TO LEVEL I DRAINAGE ANALYSIS Performed by: Larry Steward, P.E. Date Performed: May 31 , 1990 The purpose of this modification is to take into account culvert sizing fronting Lincoln Ave. , NE (west side) as necessitated by City of Renton mandated improvements to Lincoln Ave. and the addiVion of two driveways to new houses. A 12" concrete culvert crosses Lincoln Ave. NE at the Southern end of the subject property. This culvert and the upstream basin contribitory to this culvert is shown on the 1" = 200 ' aerial accompanying this report . The swale that drains this subbasin is 2100 ' long and crosses NE 36th Street at a low point in a sag curve. The condition or size of the culvert at this location could not be determined as vegation was too heavy to find it. The culvert across from the Short Plat (SH PL-061091 ) was 2/3 full of silt creating a blockage situation whereby any storm event could overtop Lincoln Ave. NE. The upper 1400 ' of drainage is in Ag C (alderwood) gravely sandy loam. This is mostly covered by alder trees with dense underbrush. The fringes are occupied by a few homes . The lower 700 ' of drainage is in a tangle of alder and dense brush which overlies a Ragner Indianola association which is about equal parts Ragner fine sandy loam and Indianola loamy fine sand . The basin drops from 303 ' to approximately 110 ' for a fall of approximately 193 ' in 2100' for a slope of 9 . 2% as an average. A good portion between 10 and 30 percent of the above areas are likely to have either neilton or everett inclusions which are gravelly and highly infiltratable. Also it appears that the ultimate development of this property in the basin area would be about 2 dwelling units per acre. This assumption is based on no sanitary sewers and a continuation of present land use patterns . As stated previously, the main purpose herein is to size a culvert. For conveyance sizing for areas less than 25 acres of which this is the rational method described in Chapter 4 of the King County Surface Water Manual shall be employed. The waterway described above is not used for fish migration as the flow is shallow and seasonal. Time of Concentration Assuming full development, the existing forest would give way to short grass pasture or lawns . Using Figure 4. 3 . 38 of SWM for 9 . 2% or 0 . 092 ft/ft, the flow will average about 2 . 3 ft/sec. The T2,.00 will then be 2100/60 * 2 . 3 15 . 2 minutes for 25 year flow of conveyance system. •JL Ali I I' III b t � 1 1 a V YVip ,... .. ,f4 iris✓h6'M+ �":::- t{,gX'T,y; - .M...• .Ma.-.-gad„rr r.,4iA Ti eR'�}'°r` bC'c:5.: ar = 266 and br = 0 . 65 where Pr 3.4" (SWM 4 . 3.3-3 and Table 4 .3. 3B. 1 ,8 = 2.66 * 15 . 2`0.65 = 0.45 I„ = 3.4 * 0 .45 = 1 .54 Land density ultimate will be 2 du/Acre or C will be 0. 36 (Table 4 . 3 .3A SWM) . Acreage of basin on East side of Lincole Ave. _ 11 .42 acres. Acreage of basin on West side of Lincoln Ave. _ 2 . 17 .acres. Check existing 12" concrete at South end of short plat which crosses Lincoln Ave. Existing slope is 6%. Q = CIA = 0 . 36 * 1 .54 * 11 .42 = 6. 33 CFS for 25 year storm. Qo.,p = 1 . 49 * 0 . 785 * 0 .250 .66 * 0.060•5 - 9 .56 > 6 . 33 O.k. Check time of concentration for West side of Lincoln Ave. " 109th Ave. SE, drain water flowing North along the West side of Lincoln Avenue to the West. The drainage course is essentially a grass choked ditch that is approximately 500' long and drops from elevation 150 ' to 106 ' or 44/500 = 0.088 ft/ft. The flow will be 3 '/second according to Figure 4 . 3. 3E of SWM. Therefore: Taoo = 500/60 * 3 = 2 .78 min. less than 6. 3 min minimum. i25 = 2 . 66 * 6.3-0. 60 = 0.80 I,a = 3 .4 * 0 .80 = 2 .72 Peak Runoff Rate Q25 = (0 . 36) (2 .72) (2 . 17) = 2. 12 CFS. Combine 2. 12 CFS with 6 . 33 CFS to obtain 8 .45 CFS. Check 12" concrete pipe at 3.05%. Qaepl, = 1 .49 * 0. 785 * 0 . 250 .66 * 0.03050-0 = 6.82 CFS N.G. 0 *012 6 .82 CFS < 8.45 CFS " enlarge to 15" Check 15" concrete pipe at 3 . 05%. Qospia = 1 .49 * 1 .227 * 0 . 31250.66 * 0.03050-5 = 12 . 35 CFS D- 012 12 . 35 CFS > 8.45 CFS o.k. Use 15" concrete pipe along short plat frontage with Lincoln Ave. Thank you, r= Larry Steward, P.E. - 11714 Jr Ave F&P- I-IkE - DG AARAY f-®�9U1-7 �7-. SURVEYING : ENGINEERING : PROJECT_DEVELOPMENT 922_SW 151st Street,Seattle,Washington 98166 (1D6)2414606 FAX(206)241-4735 May 31, 1990 Job #907-054 LEVEL I DRAINAGE ANALYSIS OWNER: BRET BORDNER PROPERTY LOCATION (TO BE SHORT PLATTED) The subject property is a portion of Lot 3, Block 3 of C.D. NILLMAN'S LAKE WASHINGTON GARDEN OF EDEN, DIVISION NO. 7. It is found on Thomas Brothers Map No. 27. It is situated in the Kennydale area north of Renton and east of the southern tip of Mercer Island. It is situated to the east on top of a low steep bluff above the outwash flats of May Creek. The property appears to be on the basin boundaries of May Creek and East Lake Washington. REVIEW OF PERTINENT RESOURCES After looking at the subject property, a trip was made to the surface water management section (5/30/90) to look at the resources referred to in the SWM Manual . The resources and my findings are listed below. 1 . Adopted basin plans and finalized drainage studies Cedar River Basin: Also a part of Eastside King County Community Planning area. 2. Basin reconnaissance reports and 1" = 400' scale problem summary maps: No complaints were listed for the period from 1982 to 1990. 3. Critical drainage area maps: Not part of critical drainage area. 4. Floodplain/floodway maps : Not part of floodplain or floodway. 5. Sensitive areas folio: I . Class III landslide area on steep slope on west side of property. II. Class III seismic area on steep slope on west side of property. III. Erosion hazard on steep slope on west side of property. This hazard is in a large degree mitigated by the heavy growth of deciduous trees on this area. IV. No wetlands andromous fish-bearing waters or 100 year flood plain. V. Water types: Nothing indicated. VI. Coal mine hazard areas: Nothing indicated. 6. SWM Division drainage investigation section problems maps: No lawsuits , claims noted for this area. The period investigated was from 1982 to 1990. 7. Wetlands inventory notebook: Nothing shown in May Creek or East Lake Washington. NARRATIVE OF DRAINAGE SYSTEM a. Upstream Portion The drainage boundary of the area tributary to the subject lot is N.E. 36th about 1/4 mile away to the south. This is where the high point is found and is a drainage divide. The land slopes to the south at approximately 10 to 15 percent through a residential area with a density of somewhat less than one dwelling unit to the acre. The eastern boundary is Lincoln Avenue N.E. (also known as 110th Avenue S.E.) . A deep drainage ditch along Lincoln Avenue contains large culverts about 2' in diameter. Page 2 These appear to be in good condition. The foliage along this ditch consists of Salmon berries, some skunk cabbage lower down, and nettles. The land to the west of the ditch contains some large well maintained homes with large lawns and sizable evergreens, both natural and planted. The soil consists of sandy silt and silty sand in varying degrees. The hydrologic soil group classification as defined by Figure 3.5.2A of the SWM Manual is Type A or B. A and B soils have low to moderate runoff potential . This land is perched between Lincoln Avenue S.E. on the east side and a 400 dropoff on the east side. The area between is about 200' wide. There is no indication of overland flow and it is assumed that the surface water is percolated downward immediately in the sandy soil . The steep bank to the west is heavily forested and shows no signs of gullying. The subject property is fairly flat with some areas of grass and some of open soil . Any water that managed to travel overland from above would be stopped at the northern boundary of the property by the access driveways to the east and a low mound on the northwest corner of the flat portion of property. Here again the sandy soil acts as a sump. The slope of the land is such that about 112 of any overland water would flow to the east and the other 112 to the west. The area is 1.04 acres. The downstream property on the west side consists of a steep bank with heavy forest below which is a flat area consisting of a field which runs over to Renton Avenue N.E. Along Renton Avenue N.E. are found some wetland type plant association. To the east side of the property lies a drainage ditch which shows no signs of over topping, scouring, bank sloughing or sedimentation. The ditch north proceeds to the intersection of Lincoln Avenue N.E. and 110th Place S.E. where a culvert crosses the road from the east and joins the ditch line coming from the south. Water was flowing through this culvert on May 30, 1990. The outfall of the culvert and ditch form a heavily brushed ravine which disappears from view and remains in its serpentine mostly subterranean passage of approximately 750 feet through extremely dense vegetation. It emerges in a clearing where a deep ditch is located. Page 3 There is some bank sloughing at this point. At first the flow is just beneath the ground at the center of the ditch as evidenced by the dark soil in contrast to the light sandy color immediately adjacent. The bank here is about 14' high on the west side and gently sloping on the east bank. There are piles of brush which appear to be a couple of years old. It appears that the property is intended for commercial use. Proceeding north along the ditch line, the bed flattens, the banks feather out and the stream becomes a small flat wetland with plants that are associated with wetlands. The water percolates into the sandy soil ordinarily. This area terminates at N.E. 44th Street and resumes again between a freeway ramp and the west side of a commercial building. Referring to the SWM Manual 1.2.4 (Care Requirements) single-family residential lots and quoting. Splash Blocks "For new proposed single-family residential lots in proposed subdivisions where the average lot area (actual , not counting common areas such as in "cluster" developments) will be 22,000 square feet or greater, splash blocks may be used in place of an otherwise required roof downspout infiltration system or drainage stubout, provided that: (1) at least 50 feet of vegetative cover (that is an area not classified as a steep slope as defined by the Sensitive Areas Ordinance and Rules) , delineated by a 50 foot building set back line, will separate splash blocks from downslope property line or top of steep slope; and (2) the roof area to each splash block will not exceed 700 square feet; and (3) the splash blocks will not discharge flow over any onsite septic tank drainfield trenches. Page 4 Also, the impervious area to be added will be less than 5,000 square feet on land where the SCS curve number will not exceed 65 or 70. In summary, I feel that no special drainage measures need to be considered for reasons enumerated in this report. AARoW CONSULTANTS LarryC.9. Steward, P.E. 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NOT 84TH OPEN ST.0 k D'CE 29 �N 201.230 Federal AC v LIJ - ►:- N 2 =n 0; --lio - cs Davin rvi ,p �N- ff L_ 237.97 II — z N N o J �2 f' 2 Carl LLn n Ln 5 I Q L tP -------- �' 4.41AC. oo 0914 I AZ I N 29S.S/ I 1 a.: 9 I1 130 Is6 4 7 r� 9 '- S.E.Nor 86TH OPEN S1- _ so 1 1 •� 7 g} N N C i • _ 7 SLY■- 117.4 I 1 O 10 23aJ., 3 4, " 1 0 ,� V •.� Isa.17 t96 0 10 � � • `1�o 6 EJ - 60 1 1 v m 1Q f l2 t86.o) ;+ 11190 -A. -- I1 . ► -- . . _. NOr oPiN.'. x .. -. .' -�:.'�' �' N,;E. 36TH ST 0 3Jb.4 1 240� ' , 1 69 CMy OF REAfTON 4FCEIVED orrY�r .�,� .,, JUN 2 9 f,qK C%US7Un�H S�yiCE *************************** JUN 2 AARAY CONSULTANTS * * 922 - SW 151st Street * LETTER OF TRANSMITTAL Seattle, WA 98166 * * Phone (206) 241-4606 *************************** Fax (206) 241-4735 TO C-IT-� oF" R"7oA( DATE 27 roAlcl Z 'REV E�pPirrF.vT� SE�VKES D1✓. RE: 1 0�Z)NEP 5Al6,e—,, AA% ATrN- DAN CAREY WE ARE SENDING YOU &,---Attached _ Under Separate Cover via the following items: Shop drawings — Prints — Plans — Samples Specifications — Change Order — Copy of Letter OTHER COAIVE?AA(C E CAt-C UL AT OArS COPIES DATE NO. DESCRIPTION GO6 E .4 E CA.4C THESE ARE TRANSMITTED as checked below: For approval _ Approved as submitted _ Resubmit _ copies for approval For your use _ Approved as noted _ Submit _ copies for distribution As requested _ For review and comment _ Returned for corrections Return corrected prints OTHER FOR BIDS DUE 19 PRINTS RETURNED AFTER LOAN TO US REMARKS: COPY TO: SIGNED: C Vl o f e1 /q,A a 0 � , -Dc, S�ve DRAINAGE ANALYS/S FOR aORD/1NER SNORT PLAT Sal P& 06I- 9/ moo/ R "N•f 7 ,!o A ITY OF RENTON RECEN® ;APR 1 51992 .;ems`OMER SERVICE 92 By.' ,)LIHI !R. 14IFNELZ IiVC.PS 3•2-1•q2 PFrz. clz-y REVIEW /o D. DUX 39G RFAlTON, WA 98057 (206) 255-2190 DNE 5f�1O� LA7_ _.�P� - ©61- q/ G15�U55101Q : THE lhl/�Qo(/�MEI�J'S Cool Sl,�T OF UP G RA01NG 774E EX lS TIN G PA VEM EN OF L 114COC N AVE N.E. 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NO ( NAt-46 It l COW-WL tOOi I4 AS 0CC-Ur22F D, r �p(ZDI�lE2 SHDI� PL.gT �2 U ZU3 SN PL - oCol ""gLCUCA-TE 4001710A)HL ��V,T- AIEA_ SIDEWAC4- /Cp--5 x S = CIS CL128 y GU Tree- /1S x/53 = Zzq D21V&kVAVs r, xzxZ 4- 20x4YZ 2zo TAPE2S 5o X Co/Z - l Sv 5oX6 / 2 = 150 ADDITloo,4C_ PA VT /53 X3,5 53S DQl vEWAys To f-lottLES f77 f cl oof = 2 co I o 470q S;F. �XIS7/NG 517� Df2 AIN,-----tLN4 _--- UN/DEVEGDPEp 'Z&3-1S S,F. (040 Cnl = LINCOCN I VE-, NE. PAVT 2 g620 S.F. (0,06)CN = 9E BAC,ta O 0E 2/ 3 (o 5,F. ro,os) CN = 14 To 74C. A25A 3/41 S s. F 5 DIG E vc (c-vEIZF17 5E2/Es) GllouP A 81OW1+107AZCAn1DS PA5 7c12 E = o,4o A c, �o,zl�t74)+ -0,05..LZ I _ (a&,S D o.&4 ,)E V E LU PED T07A t- 51 T E 02A/h//N6 TO 1-1tiZo ,l A V E NL — a 'BS MOC-3 1 021 VE KAI,/ 3000 5 = EA x 2 = &000-S,F l/NCOc ,l AVE NF (i8.s t 5)( Is3) PAVT F. rL- = ' 40 ,SIDEwAIX 7/?AhSl71c 4cw =U p2l vE lug+y3 i Sx 2x Z c :a -t- Zn,r 4x 7 t Co O LAWNS _ 3 141 S S•F. H2Eq = 2agIO SiF LANDSCAP146 CN 6 s.F. P4V'T /te-6jF CN= 95 ( U. 24 AC) p REUISf-() 311k-CAZ- oolzDNE2 IH027 PL47 9Zvzo3 rC C, c 1(1S RN6 CONDITION) 5HEe7 FCl-ow L=- 140 SHEE7 FGOu/ L 80' S= 2/ °�o VI 5- O,40 DE UELOPE� COn/DIT1U�v..s Sf/EET FLOW 3°la Y1S= 0,(S SHEET FXW L = 601 5 IS°l. VIs= O,�S P Z��2 = 2,0 " t4OrE; Po(Z Mae Df-yplt_ p 100 y2 = 3, 7 sv(EET PLIouJ CALCOLA-10Z 0 tAl P(47 �IL� ASP ©,!s t-Fs /00 y2IZ4/te Q (Ifv) = o, 'L7 CFS 100 V2l Z4tte TIaErZEFD 2F I&-c SKTIoN /, 2, 3 Cui�'c 17EC�11, a PAGE l-Z.3 -5 Sr T6- /S E-XEi`?PT F1201-1 ON-`,M57 PF/3e 2kT.E 2uti10FF CC"7120i- SINCE Q "� 0, OCFS PIPE Iawo ; y !N`PE`7 10111 — c�K 3/21/92 John Newell, Inc. page 1 BORDNER SHORT PLAT SH PL-06-91 100 YR EVENT/ 24 HR BASIN SUMMARY BASIN ID: DE100 NAME: DEVELOPED W/ 100 YR. SBUH METHODOLOGY TOTAL AREA. . . .. . . : 0. 72 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 .90 inches AREA. . : 0.48 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68. 00 TIME OF CONC. . . . . : 18. 42 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 24 Acres CN. . . . . 98 . 00 TcReach - Sheet L: 140. 00 ns: 0. 1500 p2yr: 2 . 00 s: 0. 0300 TcReach - Sheet L: 80. 00 ns: 0. 1500 p2yr: 2 . 00 s: 0. 1500 PEAK RATE: 0. 27 cfs VOL: 0. 12 Ac-ft TIME: 480 min BASIN ID: EX100 NAME: EXISTING W/ 100 YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0.72 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0. 66 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68. 50 TIME OF CONC. . . . . : 21. 34 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 06 Acres CN. . . . . 98 . 00 TcReach - Sheet L: 140. 00 ns: 0. 1300 p2yr: 2 . 00 s: 0. 0290 TcReach - Sheet L: 80. 00 ns: 0.4000 p2yr: 2 . 00 s: 0. 2100 PEAK RATE: 0. 15 cfs VOL: 0. 08 Ac-ft TIME: 480 min 3/21/92 John Newell, Inc. page 2 BORDNER SHORT PLAT SH PL-06-91 100 YR EVENT/ 24 HR DETAIL BASIN SUMMARY BASIN ID: DE100 NAME: DEVELOPED W/ 100 YR. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0. 72 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0. 48 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68. 00 TIME OF CONC. . . . . : 18 . 42 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 24 Acres CN. . . . . 98. 00 TcReach - Sheet L: 140. 00 ns: 0. 1500 p2yr: 2 . 00 s: 0. 0300 TcReach - Sheet L: 80. 00 ns: 0. 1500 p2yr: 2 . 00 s: 0. 1500 PEAK RATE: 0. 27 cfs VOL: 0. 12 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 350 0.0453 690 0.0767 1030 0.0504 1370 0.0501 1710 20 360 0.0479 700 0.0765 1040 0.0492 1380 0.0502 1720 30 370 0.0495 710 0.0766 1050 0.0485 1390 0.0503 1730 40 0.0007 380 0.0504 720 0.0768 1060 0.0482 1400 0.0504 1740 50 0.0021 390 0.0511 730 0.0771 1070 0.0480 1410 0.0504 1750 60 0.0039 400 0.0518 740 0.0775 1080 0.0480 1420 0.0505 1760 70 0.0058 410 0.0578 750 0.0778 1090 0.0480 1430 0.0506 1770 80 0.0075 420 0.0673 760 0.0782 1100 0.0480 1440 0.0507 1780 90 0.0091 430 0.0742 770 0.0750 1110 0.0481 1450 0.0399 1790 100 0.0105 440 0.0861 780 0.0698 1120 0.0482 1460 0.0228 1800 110 0.0125 450 0.1013 790 0.0669 1130 0.0482 1470 0.0131 1810 120 0.0149 460 0.1377 800 0.0654 1140 0.0483 1480 0.0075 1820 130 0.0167 470 0.2235 810 0.0646 1150 0.0484 1490 0.0043 1830 140 0.0181 480 0.2685 820 0.0642 1160 0.0485 1500 0.0025 1840 150 0.0193 490 0.2363 830 0.0641 1170 0.0486 1510 0.0014 1850 160 0.0202 500 0.1945 840 0.0642 1180 0.0486 1520 0.0008 1860 170 0.0220 510 0.1630 850 0.0643 1190 0.0487 1530 0.0005 1870 180 0.0242 520 0.1457 860 0.0644 1200 0.0488 1540 0.0003 1880 190 0.0258 530 0.1274 870 0.0646 1210 0.0489 1550 0.0002 1890 200 0.0269 540 0.1083 880 0.0648 1220 0.0490 1560 1900 210 0.0278 550 0.0977 890 0.0633 1230 0.0491 1570 1910 220 0.0285 560 0.0919 900 0.0608 1240 0.0491 1580 1920 230 0.0301 570 0.0889 910 0.0594 1250 0.0492 1590 1930 240 0.0322 580 0.0876 920 0.0587 1260 0.0493 1600 1940 250 0.0336 590 0.0871 930 0.0583 1270 0.0494 1610 1950 260 0.0346 600 0.0871 940 0.0582 1280 0.0495 1620 1960 270 0.0352 610 0.0875 950 0.0582 1290 0.0495 1630 1970 280 0.0357 620 0.0879 960 0.0583 1300 0.0496 1640 1980 290 0.0375 630 0.0885 970 0.0584 1310 0.0497 1650 1990 300 0.0399 640 0.0891 980 0.0585 1320 0.0498 1660 2000 310 0.0414 650 0.0862 990 0.0586 1330 0.0498 1670 2010 320 0.0424 660 0.0813 1000 0.0588 1340 0.0499 1680 2020 330 0.0430 670 0.0786 1010 0.0564 1350 0.0500 1690 2030 340 0.0435 680 0.0773 1020 0.0525 1360 0.0501 1700 2040 3/21/92 John Newell, Inc. page 3 BORDNER SHORT PLAT SH PL-06-91 100 YR EVENT/ 24 HR DETAIL BASIN SUMMARY BASIN ID: EX100 NAME: EXISTING W/ 100 YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0.72 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0. 66 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68 . 50 TIME OF CONC. . . . . : 21. 34 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 . 20 AREA. . : 0. 06 Acres CN. . . . . 98 . 00 TcReach - Sheet L: 140. 00 ns: 0. 1300 p2yr: 2 . 00 s: 0. 0290 TcReach - Sheet L: 80. 00 ns: 0. 4000 p2yr: 2 . 00 s: 0. 2100 PEAK RATE: 0 . 15 cfs VOL: 0. 08 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 350 0.0112 690 0.0604 1030 0.0433 1370 0.0441 1710 20 360 0.0118 700 0.0604 1040 0.0423 1380 0.0442 1720 30 370 0.0122 710 0.0607 1050 0.0417 1390 0.0443 1730 40 0.0001 380 0.0125 720 0.0610 1060 0.0414 1400 0.0444 1740 50 0.0005 390 0.0129 730 0.0614 1070 0.0412 1410 0.0445 1750 60 0.0009 400 0.0138 740 0.0619 1080 0.0411 1420 0.0446 1760 70 0.0013 410 0.0168 750 0.0624 1090 0.0412 1430 0.0447 1770 80 0.0018 420 0.0215 760 0.0629 1100 0.0412 1440 0.0448 1780 90 0.0022 430 0.0261 770 0.0608 1110 0.0413 1450 0.0363 1790 100 0.0025 440 0.0333 780 0.0572 1120 0.0414 1460 0.0225 1800 110 0.0030 450 0.0427 790 0.0550 1130 0.0415 1470 0.0140 1810 120 0.0036 460 0.0637 800 0.0538 1140 0.0416 1480 0.0087 1820 130 0.0040 470 0.1144 810 0.0531 1150 0.0417 1490 0.0054 1830 140 0.0044 480 0.1486 820 0.0529 1160 0.0418 1500 0.0033 1840 150 0.0047 490 0.1406 830 0.0528 1170 0.0419 1510 0.0021 1850 160 0.0050 500 0.1229 840 0.0529 1180 0.0420 1520 0.0013 1860 170 0.0054 510 0.1080 850 0.0530 1190 0.0422 1530 0.0008 1870 180 0.0059 520 0.0997 860 0.0533 1200 0.0423 1540 0.0005 1880 190 0.0063 530 0.0897 870 0.0535 1210 0.0424 1550 0.0003 1890 200 0.0066 540 0.0782 880 0.0538 1220 0.0425 1560 0.0002 1900 210 0.0069 550 0.0715 890 0.0527 1230 0.0426 1570 0.0001 1910 220 0.0070 560 0.0678 900 0.0509 1240 0.0427 1580 1920 230 0.0074 570 0.0658 910 0.0499 1250 0.0428 1590 1930 240 0.0079 580 0.0650 920 0.0493 1260 0.0429 1600 1940 250 0.0083 590 0.0649 930 0.0491 1270 0.0430 1610 1950 260 0.0085 600 0.0652 940 0.0490 1280 0.0431 1620 1960 270 0.0087 610 0.0657 950 0.0490 1290 0.0432 1630 1970 280 0.0089 620 0.0664 960 0.0491 1300 0.0433 1640 1980 290 0.0093 630 0.0672 970 0.0492 1310 0.0435 1650 1990 300 0.0099 640 0.0681 980 0.0494 1320 0.0436 1660 2000 310 0.0102 650 0.0665 990 0.0496 1330 0.0437 1670 2010 320 0.0105 660 0.0633 1000 0.0498 1340 0.0438 1680 2020 330 0.0107 670 0.0616 1010 0.0480 1350 0.0439 1690 2030 340 0.0108 680 0.0607 1020 0.0451 1360 0.0440 1700 2040 '2 ZI File Basin Hydrograph Storage Discharge Level pool o SHEET FLOW CALCULATOR - INITIAL 300 FEET o o 'DESoMannings Sheet Flow. . . . . : 0. 1500 0 0 OARE*Flow Length (ft) . . . . . . . . : 140. 00 *HOICES 'RAI*2 yr 24 hr rainfall (in) : 2 . 00 'TIM*Land Slope (ft/ft) . . . . . . : 0. 0300 0 *TIMO COMPUTED TRAVEL TIME (min) : 13 .79 oRAIo TYPICAL MANNINGS VALUES FOR INITIAL 300 FT oA 'ABSo *BAS*Smooth Surfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 011 *STO*Fallow Fields of Loose Soil Surface. . . . . . . . . . . . . . . 0. 05 OY *Cultivated Soil with residue cover (s<=0.2 ft/ft) : 0. 06 qPER*Cultivated Soil with residue cover (s>0. 2 ft/ft) . : 0. 17 o .AREOShort prairie grass and lawns. . . . . . . . . . . . . . . . . . . . . 0. 15 0 *CN oDense grasses. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . : 0. 24 oBermuda grass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.41 0 *Range (natural) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 0. 13 0o 'PEA*Woods or forest with light underbrush. . . . . . . . . . . . : 0. 40 *PEA*Woods or forest with dense underbrush. . . . . . . . . . . . : 0.80 0 0 *TOT' -FlOKey: QUIT F5Key: CLEAR *ete o o Pgaeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeefit aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef File Basin Hydrograph Storage Discharge Level pool SHEET FLOW CALCULATOR - INITIAL 300 FEET o o 'DESoMannings Sheet Flow. . . . . : 0. 1500 o 0 *AREoFlow Length (ft) . . . . . . . . : 80. 00 OHOICES o oRAI*2 yr 24 hr rainfall (in) : 2 . 00 0 OTIMoLand Slope (ft/ft) . . . . . . : 0. 1500 0 *TIMo COMPUTED TRAVEL TIME (min) : 4 . 63 oRAI- TYPICAL MANNINGS VALUES FOR INITIAL 300 FT A o *ABS* *BASoSmooth Surfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 011 'STOoFallow Fields of Loose Soil Surface. . . . o . . . . . . . . . : 0. 05 OY oCultivated Soil with residue cover (s<=0. 2 ft/ft) : 0. 06 'PERoCultivated Soil with residue cover (s>0. 2 ft/ft) . : 0. 17 *ARE*Short prairie grass and lawns. . . . . . . . . . . oo . . . . . . . : 0o15 o 'CN *Dense grasses. . . . . . . . . o . . . . . . - . 00 . . . . . . . . . . . . . . . : 0.24 0 o 'Bermuda grass. . . . . . . . . . . . . . . . . - 0 . . . . . . . . . . . . . . . . : 0.41 o oRange (natural) . . . . . . o - . . . . . . . . . . . . . . . . o . . . . . . . : 0o13 'PEA*Woods or forest with light underbrush. . . . . . . . . 0.40 *PEAoWoods or forest with dense underbrush- . . . . 0.80 'TOTo -FlOKey: QUIT F5Key: CLEAR oete o o aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef File Basin Hydrograph Storage Discharge Level pool INPUT, MODIFY OR BROWSE DATA o BASIN ID DE100 SBUH HYDROGRAPH o o oJ%REo TIME OF CONC WORKSHEET *NFALL CHOICES o oRAio <----Tc Reach Type----> Tt(min) OTYPE IA o 1)FAJF�u0,f v C0ri0�_ °TIM° *TYPE I ° °TIM°REACH 1 [SHEET] [SHALLOW] [CHANNEL] 13 .79 *TYPE II ° °RAI°REACH 2 [SHEET] [SHALLOW] [CHANNEL] 4 . 63 °TYPE IIA ° -ABS-REACH 3 [SHEET] [SHALLOW] [CHANNEL] 0. 00 *TYPE 3 ° °BAS°REACH 4 [SHEET] [SHALLOW] [CHANNEL] 0. 00 *USER 1 ° °STO°REACH 5 [SHEET] [SHALLOW] [CHANNEL] 0. 00 *KC 7 DAY ° *CUSTOM ° °PER°Tc, sum of travel times (min) . . . . 18.42 ° °ARE° °CN °F10Key: QUIT FSKey: CLEAR 0 ° aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef ° SUMMARY DATA ° °PEAK HYDROGRAPH TIME: 8 . 00 hrs ° 'PEAK HYDROGRAPH FLOW: 0.2685 cfs ° 'TOTAL HYDROGRAPH VOL: 0. 1190 ac-ft ° ° HOME END F1:Find F2 :New F3 :Get F4 :Tc-Calc F5:Delete ° • Pgup Pgdn F6:Compute F7 : F8 :Method F9:Template F10:Exit ° aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef 2 51? 1, cl-L File Basin Hydrograph Storage Discharge Level pool o SHEET FLOW CALCULATOR - INITIAL 300 FEET :DES:Mannings Sheet Flow. . . . . : 0. 1300 'ARE*Flow Length (ft) . . . . . . . . : 140. 00 *HOICES o *RAI02 yr 24 hr rainfall (in) : 2 . 00 'TIMOLand Slope (ft/ft) . . . . . . : 0. 0290 o *TIM* COMPUTED TRAVEL TIME (min) : 12 .47 oRAIG TYPICAL MANNINGS VALUES FOR INITIAL 300 FT A *ABSO 'BASoSmooth Surfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 011 *STO*Fallow Fields of Loose Soil Surface. . . . . . . . . . . . . . . 0. 05 oy o *Cultivated Soil with residue cover (s<=0. 2 ft/ft) : 0. 06 'PER*Cultivated Soil with residue cover (s>0.2 ft/ft) . : 0. 17 'ARE*Short prairie grass and lawns. . . . . . . . . . . . . . . . . . . . . 0. 15 o 'CN oDense grasses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.24 o oBermuda grass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.41 o 'Range (natural) . • natural) . . . . . . o . . . . . . . . . . . . . . . . . . . . . o . : 0o13 o 'PEAoWoods or forest with light underbrush. . . . . . . . . . . . . 0. 40 *PEAoWoods or forest with dense underbrush. . . . . . . . . o . . : 0. 80 o o *TOTo * 0F10Key: QUIT F5Key: CLEAR oete o o pg&666666666666&666666666666666666666beeeeeeeeeeeeeeeeeeeeeeeeedfit o aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef File Basin Hydrograph Storage Discharge Level pool o o SHEET FLOW CALCULATOR - INITIAL 300 FEET o *DES*Mannings Sheet Flow. . . . . : 0.4000 0 *ARE*Flow Length (ft) . . . . o . . . : 80. 00 *HOICES oRAI*2 yr 24 hr rainfall (in) : 2 . 00 o oTIMoLand Slope (ft/ft) . . . . . . : 0. 2100 o oTIM* COMPUTED TRAVEL TIME (min) : 8 . 87 oRAIo TYPICAL MANNINGS VALUES FOR INITIAL 300 FT A oABS* *BASoSmooth Surfaces. . . . o . . . . . . . o . . . . . . . . . . . . o . . . . . . . 0. 011 *STOOFallow Fields of Loose Soil Surface— . . . . . . . 0. 05 *Y 0 o oCultivated Soil with residue cover (s<=0. 2 ft/ft) : 0. 06 'PERoCultivated Soil with residue cover (s>0. 2 ft/ft) . : 0. 17 oARE*Short prairie grass and lawns. . . . o . . . . . . . . . o . . . . o : 0o15 'CN *Dense grasses. . . . . . . . . . 0 . . . 00 . . . . . . . . . . . . . . . . . . . . : 0o24 G *Bermuda grass. . . . . - 0 . . . . o . . . . . . . o . . . . . . . o . . . . . . . : 0.41 *Range (natural) . . . . . . 0. 13 oPEA*Woods or forest with light underbrush— . . . . . . . . . . : 0. 40 'PEA*Woods or forest with dense underbrush. . . . . o . . . . . . : 0.86 'TOT* * *F10Key: QUIT F5Key: CLEAR oete o o aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef File Basin Hydrograph Storage Discharge Level pool INPUT, MODIFY OR BROWSE DATA o BASIN ID EX100 SBUH HYDROGRAPH o OARE-A 'NFALL CHOICES ' TIME OF CONC WORKSHEET oi;mio <----Tc Reach Type----> Tt(min) *TYPE IA °TIM° *TYPE I ° °TIM°REACH 1 [SHEET] [SHALLOW] [CHANNEL] 12 .47 *TYPE II ° °RAI°REACH 2 [SHEET] [SHALLOW] [CHANNEL] 8.87 *TYPE IIA ° -ABS-REACH 3 [SHEET] [SHALLOW] [CHANNEL] 0.00 °TYPE 3 ° °BAS°REACH 4 [SHEET] [SHALLOW] [CHANNEL] 0. 00 °USER 1 ° °STO°REACH 5 [SHEET] [SHALLOW] [CHANNEL] 0. 00 °KC 7 DAY ° o ° *CUSTOM ° °PER°Tc, sum of travel times (min) . . . . 21. 34 ° °�° ° ° . .. ° °CN °F10Key: QUIT FSKey: CLEAR . .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ° aee ee e ee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef ° SUMMARY DATA ° °PEAK HYDROGRAPH TIME: 8. 00 hrs ° *PEAK HYDROGRAPH FLOW: 0. 1973 cfs ° °TOTAL HYDROGRAPH VOL: 0. 0916 ac-ft HOME END F1:Find F2 :New F3 :Get F4:Tc-Calc F5:Delete ° °' Pgup Pgdn F6:Compute F7 : F8 :Method F9:Template F10:Exit ° .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. aeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeef KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.2B SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type 1 A rainfall distribution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION A B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89• 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed 42 64 76 81 Wood or forest land: young second growth or brush 55 72 81 - 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89, 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 98 Open water bodies: lakes, wetlands, ponds, etc. 0 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre % Impervious (3)1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, % impervious condominiums, apartments, must be computed commercial business and industrial areas. (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 3.5.2-3 1/90 35 AV Iaw w 11 Wi — r 3f AY Nlrfl- n 7"' r ■ I 3S M1 iu%l � 3S M/ NaGSI R NL%t+a Y Nu• 4r� ♦ " •sH � l I �t. I � I ..yAVNiVSI O � .ENK fi• C 1 � j E I � PE .• S n0 ar � t� � �Lo v �r i ;� �� W ftv ♦o FdraEFCI 1a' �1 '���¢, t W J'nn L & y � � ,� d�••�► 36 �,r 7l'� .4,, "1 � C W � r=� w rE L ,� °3 •i'r',;; V •I_ �,�{/i ' r. s �9 ,::"��g I'.I rr r` t Y2 L i JE 'J'^V M�96i I x 1• 'P l• .�;, I �•6 Gir' t II '3C a a " 11 NNl wS•1 j, o 34 � EEa rl � �' � rLHun wr -4�Q�J° L__ o `�• ;:j I N y : W Air» , y� �i ro r>•�+ 9Slldr tllll �"i1 a,�' L. .E I ;AY lS M O12N Ill N"T - •r♦O oii 'b L 1::..' E 7 � 35 NS48Z nr wr1 t• �� � i tt ulw r w YV 1 ,Y NAV SE YY 1 i CY .fs fP C �• U) 'Y S nr Nlrtt '1 Yy 221H AV q 1 141, 'tt1H _ A •[S r "� IC � Q I T I M1SC1 Z 3f rHL941 35 .. Qj 5• 5 SE ,7 t � l COPI ,,- �qqq,,, y Ar Nasct rr ah V Yv tl r. .. Ir 1� r 1 6,� E t i•. V ,Ir Z -�- A V I ., PINS Y'1 f, VJ 35 • M gel +:1 arfvmoo.. s AV4 • ,. -I Mi '' Ira AY W • ( t Q'I-�W AV 0=1 " E , ^� 1 Tj- mot.. r ��'� tt�.,I� � � .•-..�.- v .fw 3S o�,ny �y :YS„ I•r•i. W3S Ar'1S1U 1/ ly yi�r t HLrI .PN 4 ' �• 1 TN SE z N1rl I � d:M.„ H1SLl '�- V —_LEI 3 4 7S All NJ W III / f TH AV„E Y " r NYtI• p I �+ CS MIY. EJ SFr C �. �v 1THAV f, NUG vi y 1e1 3M1Yt1 ?iR! WQ 1 7'• "'t a°J: a I Ix�W � � ePKW'f Wr:+s�� #' u/ ��•� � F v �, I M r <`'<a. a <� n Ill�l r r GPEVt.,:: a AV, r � IS AV H1Yl y • ,? •ew X mat ¢ _ 7 (p 4 c.3• ',w �rw'•3s�eA "' =dpYS d'".cE '" slt Yf �. AtC. Owns -'>i'i Ar" t I AV HLfI u•:Av at I li b 3 pyftt"' 1/ W W Ar n 1 w•� l 1 ' Gip 3S At ♦�a,Cz r JAY wIIt q �y I • _� F3 �`'f fa PV �i TN Ay I 8 3 l J ......Av ...... ti I a 3c nr y�l JN' NaOZI N I l 1 TH^ 5E t\\ I •35� AV: ILLYtI ( 3s nr Naotl _ � I � a W y o ��a N, ,.�I \ s •. nv �jLLJ r � a ](�� 3 S '_ ♦ `�6J�N5 A J a[ 1 Ti � N g3SN •.•�'i•rd NltitlWN ¢_.w. w W E ^iC'-'••{11jtR I •�� ~�:� a2>�E6. I,t� I �+�'. -- I 4 3S �3Y"��IEYI( •I .... ....I.. EY 4 _ _........I._ o•.• \1• 's _y,+b vt.BAu sHa>�.cwk! .n, C yl ONI VM 35 AV I ? Sfi Nllll 9 1 E.� n 111 N It • - AV f Ar lffO]NIl r k.` - L' l�• Hyf04' 1LEIlrY1 w x —AV— g, Hr'NW yt Cp r 'HI ppyl32r - N V_ a M sr i LZ 4DW aaS / �f��r►� r loll� I ry„y]1 pE .y 11¢Ir;: • ' GIs.'#r1 �4 ,y n nnr� �,.4j�'a ��p�r,1 r� � I' �•'t' k f 'ryf'P-ns � �'a- �2 i�"�it! � '. _ 211 gx r�14 , ONO El ii kv ail/�1. �►s1 NAI + � r WARO r KpD - --- - - - AkF '� 2 Z 8 11 ;'. 4Q5i gh •ilk j KpB An Ep T Ar C li AkF IA-(;I r \ e,Qh AgC a qUj I f I G� a Q gM ,.r W • BM Pleasure 8 Point 21 ; ..4'�� I 5 a :.� Pqr xitl+ 28 reSt PC �nG • i ur AMC AMU aZ F i I n C. ,. , / • '�M Bh• , AkF AkF e QQBN B b -- -- -,r-- 29 2 3 l •A6C, 42 - - - I BeC m �Or KqD off' AgC KPB• t 'Pi ewpo AgD \' n t Hills EwC —_ J InA . + e i AgC; •ii rJ .••• AgB t u � I a AmC 4) • E W + ., ourse KpD a j =i• �L , n G k -- .• AgD 3 •• 498• _ +� 8M n r I EvC Pp A6C B AmC I I Bh Bh t••y AgC 1 r / May eta KPC r .II LVU wo BM - h 109 OvD 7 �� :' ------ --.?------- � Lod✓' - - AUC I (� NU AgC \ BMD n I• t ` u• I 605 1j 1 SM AgC I / AgC - pa AgD` 'ti 1 ASU Or I n .•AgC •.• 0` FLU 'I: KennydWe .. is '. •"r tl. I: ;:� •InC I AkF I AkF •• /A,, AkF y I EvB r AGC I BU(:' • Py GHA VEL ; Coleman Poin rt P,r • A • I De « t•. ''.. 30G Aj;C • �I9 • 6vB I �''• .� _• + y II...E 0 f y - _. r t11 \\ •AgC ' AkF t i mil+ hti' 11 •a ," f '1 rAMC t • r ,'t InG , M 1 AgD o •� �� ' P ..;;'';.;-•,'� ( , •AgC Mawr n •' AkF •�I I�• Ur I 1 1 .. :r' KIN (J UU U IN 1 1, W tHJr111r U 1 U 11, O v na " %. a. ♦• — a --. — — — — • — - FIGURE 3.5.2A HYDROLOGIC SOIL GROUP OF THE SOILS IN KING COUNTY HYDROLOGIC HYDROLOGIC SOIL GROUP GROUP* SOIL GROUP GROUP' Alderwood C Orr-as Peat D Arents, Alderwood Material C Oridia D Arents, Everett Material B Ovall C Beausite C Pilchuck C Bellingham D Puget D Briscot D Puyallup B Buckley D Ragnar B Coastal Beaches Variable Renton D Earlmont Silt Loam D Riverwash Variable Edgewick C Salal C Everett 'A Sammamish D Indianola Seattle D Kitsap C Shacar D Klaus C Si Silt C Mixed Alluvial Land Variable Snohomish D Neilton A Sultan C Newberg B Tukwila D Nooksack C Urban Variable Normal Sandy Loam D Woodinville D HYDROLOGIC SOIL GROUP CLASSIFICATIONS A. (Low runoff potential). Soils having high infiltration rates, even when thoroughly wetted, and consisting chiefly of deep, well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. B. (Moderately low runoff potential). Soils having moderate infiltration rates when thoroughly wetted, and consisting chiefly of moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission. C. (Moderately high runoff potential). Soils having slow Infiltration rates when thoroughly wetted, and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine textures. These soils have a slow rate of water transmission. D. (High runoff potential). Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a hardpan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission. • From SCS, TR-55, Second Edition, June 1986, Exhibit A-1. Revisions made from SCS, Soil Interpretation Record, Form #5, September 1988. 3.5.2-2 I/90 DETERMINATION OF NON-SIGNIFICANCE-MITIGATED MITIGATION MEASURES PROJECT: Bordner Short Plat PROPONENT: Bordner Construciion APPLICATION NUMBER: ECF;SHPL-061-91 DESCRIPTION OF PROPOSAL: The applicant seeks to short plat an existing 1.04 acre parcel Into two lots, both of which are 14,631 SF in area. The owner plans to build two (2) single-family homes, one on each lot. LOCATION OF PROPOSAL: Lincoln Avenue near NE 49th Street CONDITIONS: The Environmental Review Committee issued a Determination of Non-Significance -Mitigated with the following conditions: 1. The applicant shall, in order to mitigate impacts to earth, water, plants and the natural environment, provide a covenant running with the land, stating: (a) that the owner(s) of Lot #1, shall have an undivided interest in Tract A, and the owner(s) of Lot #2, shall have an undivided interest in Tract B; (b) that no development will take place on Tract A and Tract B in perpetuity, other than that needed for the installation of utilities and septic system drainfields; (c) that trees, shrubs and plants that currently exist on Tract A and Tract B, shall not be removed, altered or disturbed in any manner without the written approval of the City of Renton. This covenant shall be prepared to satisfaction of the Development Planning Section and the City Attorney, and be recorded at the time the short plat is recorded. 2. The applicant shall, in order to mitigate Impacts to the ground, provide a covenant running with the land, stating that the use of septic systems are permitted as no connection to sewer lines is feasible at this time, and that the owner(s) of Lot #1 and Lot #2 agree to make a connection to the sanitary sewer when the City of Renton determines that such a connection is feasible. This covenant shall be prepared to the satisfaction of the Development Planning Section and the City Attorney, and be recorded at the time the Short Plat is recorded. 3. The applicant shall, in order to mitigate impacts to the natural environment, provide evidence of King County Health Department approval for the use of septic systems for Lot #1 and Lot#2. NOTE #1: The applicant shall be called upon to provide all required public improvements including water service, storm drainage (designed and constructed to City of Renton standards). Improvements must also be provided to the portion of Lincoln Avenue abutting the short plat, including installation of curbs, gutters, sidewalk, planting strip and street lighting, all in accordance with City of Renton standards for Residential Access Streets. Utility improvement service fees (SUCC) will be required to be paid to the City prior to the recording of the short plat. Finally, the applicant/owner shall be called upon to provide a voluntary contribution of$150.00 per lot, to the improvement of public recreation facilities (as described in the Comprehensive Parks Plan guidelines). 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Plat (PP# ) CAG# �sHP<. - 061-71 To: Technical Services Date 8 -Z/o/ 9 2 WO# 6.f / S Green# no.vc. k n o y..ti From: Plan Review/Project Manager 6i yr ,e Project Name p r d n t r s orf (70 characters max) Description of Project: 'S Y e l4 S f r e dl- jM* 1teV6 Jn eh �41ia/,X, a t��! si //C 1 driycK.ayr/ r<Iec -Are hv f 789 P o4 Circle Size of Waterline: 8" 10" 12" Circle One: New or Extension Circle Size of Sewerline: 8" 10" 12" Circle One: New or Extension N.%%� Circle Size of Stormline: 12" 15" 18" 24" Circle One: Ne or Extension Address or Street Name(s) Dvlpr/Contractor/Owner/Cnslt: r d n f-t,-t,( c-/i*d 1 g YG& 6 o r'd n,,r (70 characters max) Check each discipline involved in Project Ltr Drwg #of sheets per discipline ✓ ✓ Trans-Storm _r-,1t 14�. 1414JA. (Roadway/Drainage) (Off site improvementsxinclude basin name) (include TESC sheets) 23 Transportation (Signalization Channelization,Lighting) _ 2 C%'A� % J ) O Wastewater (Sanitary Sewer Main)(include basin name) LK Water (Mains,Valves,Hydrants) ✓ ✓ O� �@ _ � Ck�— L��""�t (Include composite&Horizontal Ctrl Sheets) TS Use Only —f_�� _ _. D_ 1�C�� tl� 10TA -- 0-?- Approved by TSM Date: fonns/misc/92-090.130C/CD/bh 29 N 88 ° 42 " W 653 . 29 ' 4 t h S T. W 70b Q 10 O o 110 w - Co Lu 140 18" CMP t XI',f RJR; I EL=99. j / I I O EXIST EA`:f 4-N1 F O� �/ M 296.20' - - - wM N88'20'27W O 1 DRIVEWAY 18" MP o CA J GRAPHIC SCALE o Mf3 J o 0 0 0 0 0 1 30' o 0 122 �o PN 7 CIO I IN FEET ) 0 r, � � � ' i inch = 20 ft L= 60 I01 i 18" CMP p 5= 21 10 INV EL=10 .61 CONTOUR INTERVAL - 2' (D I B.M INFORMATION TAKEN FROM CITY OF RENTON CARD No 1223. 5 2- TOP RAILROAD SPIKE 0.5' UP W. FACE N88'20'27"W I, Q� 1181 i POWER POLE E. SIDE JONES AVE N.E. -- - ` --____2 9 6-2Il'- (N.W. COR HOUSE #4024) POWER POLE - #4024. B.M. ELEV = 44.06 Irl F.B. 612 PG 25; 4-18-88 r 5 Cdeu)- 0.15 1 N Cei) = G 5 \ f3�ZU S N, w C I 1 G/tL N (deu RS TOP OF J = 8 I STEEP SLOPE q0 M E 7(Z EES 1 I �', I PASTURa h ED siCex)-d,4D o I I 1 \ n (deu 20 \ CAN C 'v)- G 8 0 Ln I t\ I12" coNc c' LV I INV EL .11 CrrYOFRENTON'I J = RECEIVED i o APR 1 5199 WM OUSTSERV10e 96.20' V I (x3) 0 [I �— 12" CONC CULV o-. ___ \ El[I i INV EL = 104.52 _ FH VALVE x6" PHON BOX BORDNER SHORT PLAT \, SHPL— 061 — 91 ,�T� ZI-11G I NIAN118 -'LbilJK-P=,: nni�N i nn EiN Tl �\JL� 71 EXISTING DRAINAGE 13ASIN A�'EVI5/0NS PEe C!Ty COMM51VT5 5-2/ 9Z : , • : ti - - (T }) . _ _ 777 1111111111110 44 { ._ ... .. moc isr.ocv 4 - Kiihit i 01 •i. r. : 1 7 • L• a s• _ 7E - .. Y .i-zx. . - .. ... .' _ ,.. -_. ._ ,- _: :_. ._ - .. .. . .... .. Vie•:-' E .. .. .. .... _.. _. .. . .... . : . .. , '. , ... ..•. -.., - -.: wit. Yam. _r J t , t w •. , .. . ,..:,_ .... - .. :mac•. _ q - i -C - �a r V ,• .. r 1 • • 1 — • .. 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