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4205 148th Ave.N.E.Suite 200 CORE Bellevue,Washington 98007 425.885.7877 Fax 425.885.7963 DESIGN ADDENDUM 1 7 TO STORM DRAINAGE ANALYSIS FOR PARKSIDE COURT RENTON, WASHINGTON c', c' a Qri p t� 371 � tv Prepared by: Jordan R. Brown, E.I.T. ISYE�I�vAL Approved by: David E. Cayton, P.E. Date: September 27, 2001 rtaEss-�2® Core No.: 01072 ENGINEERING PLANNING SURVEYING STORM DRAINAGE R/D FACILITY ADDENDUM PER CITY OF RENTON COMMENTS As requested by the first City review comments, we have produced a copy of the KCRTS Duration Curves as the comparison analysis according to KCSVWDM Level-Two Flow- Control. In addition, we have completed a Duration Comparison Analysis in the KCRTS Analysis Tools menu. Upon closer inspection of the Duration Comparison. Analysis, the exceedance of positive excursion was slightly more than the allowed 10%, at 12.2%. The designed pond is larger than that which is required. Nevertheless, re-routing the pond with a slightly larger area and re-running the duration comparison analysis showed no positive excursion. Therefore, the updated facility routing table, duration comparison analysis, duration curve comparison graph, and pond stage storage table are included as an addendum to the Storm Drainage Analysis Report dated July 2, 2001. Parkside Court KCRTS Level Two Flow Control Flow Duration. Analysis Graph Discharge vs. Probability Exceedance F L a r„ 01072exterg.dur Q 'S R \ •� w ass *`^ � N C.? a— 00 4n. O 10 -5 10 _4 10 -3 10 10 -1 10 0 Probability Exceedence 09/1.7/01 11:09 AM Duration Comparison Anaylsis Base File: 01072dev.tsf New File: 01072-p2-rdout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time----- ---------Check of Tolerance------- CutoffBase New %Change Probability Base New %Change 0.136 0.29E-01 0.46E-02 -84.1 I 0.29E-01 0.136 0.083 -38 .7 0.162 I 0.23E-01 0.42E-02 -81. 9 I 0.23E-01 0.162 0.087 -46.2 0.189 I 0.19E-01 0.32E-02 -83.2 1 0. 19E-01 0.189 0.092 -51.5 0.215 I 0. 15E-01 0.23E-02 -84.5 I 0.15E-01 0.215 0.095 -56.1 0.242 I 0.12E-01 0.19E-02 -84.3 I 0. 12E-01 0.242 0.098 -59.4 0.268 I 0.99E-02 0. 14E-02 -86.2 I 0. 99E-02 0.268 0.101 -62.5 0.295 I 0.84E-02 0.77E-03 -90.8 I 0.84E-02 0.295 0.103 -65.1 0.321 I 0.72E-02 0.42E-03 -94.1 I 0.72E-02 0.321 0.104 -67.7 0.348 I 0. 62E-02 0.16E-03 -97.4 I 0.62E-02 0.348 0.105 -69.8 0.375 I 0.50E-02 0.33E-04 -99.3 1 0.50E-02 0.375 0.117 -68.7 0.401 I 0. 44E-02 0.33E-04 -99.3 0.44E-02 0.401 0.152 -62.2 0.428 I 0.37E-02 0.33E-04 -99.1 1 0.37E-02 0.428 0.177 -58.5 0.454 I 0.32E-02 0.33E-04 -99.0 I 0.32E-02 0.454 0.186 -59.0 There is no positive excursion. Maximum negative excursion = 0.253 cfs (-70.4%) occurring at 0.360 cfs on the Base Data:01072dev.tsf and at 0.106 cfs on the New Data:01072-p2-rdout.tsf STORM WATER DETENTION POND VOLUME CALCULATIONS PROJECT NAME: PARKSIDE COURT 01072 BY: JRB ELEVATION INCREMENTAL TOTAL LIVE VOLUME VOLUME VOLUME SF CF CF CF 386.0 1,720 2,226 387.0 2,732 2,226 3,006 388.0 3,280 5,232 7,960 390.01 4,6801, 13,192 5,230 391.0 51780 18,422 S 391.0 6,210 392.0 6,640 u„, 24,6321 6,210 15,000 394.0 8,360 39,632 21,210 18,560 396.0 10,200 58,192 39,770 10,660 397.0 11.120 68,852 50,430 DESIGNED REQUIRED PERMANENTIWQ VOLUME (CF) : 18,422 17,812 LIVE STORAGE VOLUME (CF) : 50,430 48,517 Retention/Detention Facility Type of Facility: Detention Pond Side Slope: 2.00 H:lV Pond Bottom Length: 105.83 ft Ar- Pond Bottom Width: 52.92 ft Pond Bottom Area: 5600. sq. ft t- Top Area at 1 ft. FB: 1082'9. sq. ft 0.249 acres Effective Storage Depth: 6.00 ft Stage 0,_.Elevation: -391.00 *Mb Storage Volume: 46182. cu. ft 1.060 ac-ft Riser Head: 6.00 ft Riser Diameter: 12.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 1.43 0.136 2 3.60 2.35 0.232 6.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation Surf Area (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft) 0.00 391.00 0. 0.000 0.000 0.00 5600. 0.01 391.01 56. 0.001 0.007 0.00 5606. 0.03 391.03 168. 0.004 0.010 0.00 5619. 0.04 391.04 225. 0.005 0.012 0.00 5625. 0.06 391.06 337. 0.008 0.014 0.00 5638. 0.07 391.07 394. 0.009 0.015 0.00 5645. 0.09 391.09 507. 0.012 0.017 0.00 5657. 0.10 391.10 563. 0.013 0.018 0.00 5664. 0.12 391.12 677. 0.016 0.019 0.00 5676. 0.22 391.22 1247. 0.029 0.026 0.00 5740. 0.32 391.32 1825. 0.042 0.031 0.00 5805. 0.42 391.42 2408. 0.055 0.036 0.00 5870. 0.52 391.52 2999. 0.069 0.040 0.00 5935. 0.62 391.62 3595. 0.083 0.044 0.00 6000. 0.72 391.72 4199. 0.096 0.047 0.00 6065. 0.82 391.82 4808. 0.110 0.050 0.00 6131. 0.92 391.92 5425. 0.125 0.053 0.00 6198. 1.02 392.02 6048. 0.139 0.056 0.00 6264. 1.12 392.12 6678. 0.153 0.059 0.00 6331. 1.22 392.22 7314. 0.168 0.061 0.00 6398. 1.32 392.32 7958. 0.183 0.064 0.00 6466. 1.42 392.42 8608. 0.198 0.066 0.00 6534. 1.52 392.52 9264. 0.213 0.068 0.00 6602. 1.62 392.62 9928. 0.228 0.071 0.00 6671. 1.72 392.72 10598. 0.243 0.073 0.00 6740. 1.82 392.82 11276. 0.259 0.075 0.00 6809. 1.92 392.92 11960. 0.275 0.077 0.00 6878. 2.02 393.02 12651. 0.290 0.079 0.00 6948. e 2.12 393.12 13350: 0.306 0.081 0.00 7018. 2.22 393.22 14055. 0.323 0.083 0.00 7089. 2.32 393.32 14767. 0.339 0.085 0.00 7159. 2.42 393.42 15487. 0.356 0.086 0.00 7230. 2.52 393.52 16214. 0.372 0.088 0.00 7302. 2.62 393.62 16947. 0.389 0.090 0.00 7373. 2.72 393.72 17688. 0.406 0.092 0.00 7446. 2.82 393.82 18436. 0.423 0.093 0.00 7518. 2.92 393.92 19192. 0.441 0.095 0.00 7591. 3.02 394.02 19955. 0.458 0.097 0.00 7664. 3.12 394.12 20725. 0.476 0.098 0.00 7737. 3.22 394.22 21502. 0.494 0.100 0.00 7811. 3.32 394.32 22287. 0.512 0.101 0.00 7884. 3.42 394.42 23079. 0.530 0.103 0.00 7959. 2+n� OfL 3.52 394.52 23878. 0.548 0.104 0.00 8033. 3.60 -w=Mjji4.60 24524. 0.563 0.105 0.00 °° 093. 3. 62 394. 62 24686. 0.567 0.107 0.00 8108. 3. 65 394.65 24929. 0.572 0.112 0.00 8131. 3. 67 394.67 25092. 0.576 0.119 0.00 8146. 3.70 394.70 25337. 0.582 0.129 0.00 8168. 3.72 394.72 25500.. 0.585 0.142 0.00 8184. 3.75 394.75 25746. 0.591 0.157 0.00 8206. 3.77 394.77 25910. 0.595 0.170 0.00 8221. 3.80 394 .80 26157. 0.600 0.175 0.00 8244. 3.90 394.90 26985. 0.619 0.191 0.00 8320. 4.00 395.00 27821. 0. 639 0.205 0.00 8396. 4.10 395.10 28665. 0. 658 0.218 0.00 8472. 4.20 395.20 29516. 0. 678 0.229 0.00 8549. 4.30 395.30 30374. 0. 697 0.240 0.00 8626. 4.40 395.40 31241. 0.717 0.250 0.00 8704. 4.50 395.50 32115. 0.737 0.260 0.00 8781. 4.60 395.60 32997. 0.758 0.269 0.00 8859. 4.70 395.70 33887. 0.778 0.277 0.00 8938. 4.80 395.80 34785. 0.799 0.285 0.00 9017. 4.90 395.90 35690. 0.819 0.293 0.00 9096. 5.00 396.00 36604. 0.840 0.301 0.00 9175. 5.10 396.10 37525. 0.861 0.309 0.00 9255. 5.20 396.20 38455. 0.883 0.316 0.00 9335. 5.30 396.30 39392. 0.904 0.323 0.00 9415. 5.40 396.40 40338. 0.926 0.330 0.00 9495. 5.50 396.50 41291. 0. 948 0.336 0.00 9576. 5.60 396.60 42253. 0. 970 0.343 0.00 9658. 5.70 396.70 43223. 0.992 0.349 0.00 9739. 5.80 396.80 44201. 1.015 0.356 0.00 9821. 5.90 396.90 45187. 1.037 0.362 0.00 9903. �y� [ .,) 6.00 397.00 46182. 1.060 0.368 0.00 9986. 1 6.10 397.10 47184. 1.083 0. 682 0.00 10069. 6.20 397.20 48195. 1.106 1.250 0.00 10152. 6.30 397.30 49215. 1.130 1.990 0.00 10235. 6.40 397.40 50242. 1.153 2.780 0.00 10319. 6.50 397.50 51279. 1.177 3.070 0.00 10403. 6.60 397.60 52323. 1.201 3.330 0.00 10488. 6.70 397.70 53376. 1.225 3.570 0.00 10573. 6.80 397480 54438. 1.250 3.800 0.00 10658. 6.90 397.90 55508. 1.274 4.010 0.00 10743. 7.00 398.00 56586. 1.299 4.210 0.00 10829. 7.10 398.10 57674. 1.324 4.390 0.00 10915. 7.20 398.20 58769. 1.349 4.580 0.00 11001. 7.30 398.30 59874. 1.375 4.750 0.00 11088. 7.40 398.40 60987. 1.400 4.920 0.00 11175. 7.50 398.50 62109. 1.426 5.080 a.00 11262. 7.60 398.60 63239. 1.452 5.240 0.00 11350. 7.70 398.70 64379. 1.478 5.390 0.00 11438. 7.80 398.80 65527. 1.504 5.540 0.00 11526. 7.90 398.90 66684. 1.531 5.680 0.00 11615. 8.00 399.00 67850. 1.558 5.820 0.00 11704. Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 2.00 ******* 1.48 6.23 397.23 48517. 1.114 2zsyT- 0.99 0.48 0.47 6.03 397.03 46498. 1.067 3 0.99 ******* 0.34 5.52 396.52 41507. 0. 953 4 1.05 ******* 0.30 5.04 396.04 36960. 0.848 5 1.19 ******* 0.28 4.76 395.76 34463. 0.791 62Y'& 0.62 ******* 0.20 3.99 394.99 27769. 0. 637 7 0.80 ******* 0.10 3.36 394.36 22572. 0.518 8 0.86 ******* 0.09 2.70 393.70 17515. 0.402 ---------------------------------- Route Time Series through Facility Inflow Time Series File:01072dev.tsf �, Outflow Time Series File:01072-P2-rdout.tsf� Inflow/Outflow Analysis �\OO a� Peak Inflow Discharge: 2.00 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 1.48 CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: 6.23 Ft Peak Reservoir Elev: 397.23 Ft Peak Reservoir Storage: 48517. Cu-Ft 1.114 Ac-Ft Flow Duration from Time Series File:01072-p2-rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % a % 0.007 38717 63.139 63.139 36.861 0.369E+00 0.020 5582 9.103 72.242 27.758 0.278E+00 0.033 4966 8 .098 80.341 19. 659 0.197E+00 0.046 4003 6.528 86.869 13.131 0.131E+00 0.059 3064 4. 997 91.866 8.134 0.813E-01 0.072 2094 3.415 95.280 4.720 0.472E-01 0.085 1350 2.202 97.482 2.518 0.252E-01 0.099 820 1.337 98.819 1.181 0.118E-01 0.112 401 0.654 99.473 0.527 0.527E-02 0.125 29 0.047 99.521 0.479 0.479E-02 0.138 13 0.021 99.542 0.458 0.458E-02 0.151 12 0.020 99.561 0.439 0.439E-02 0.164 16 0.026 99.587 0.413 0.413E-02 0. 177 24 0.039 99. 627 0.373 0.373E-02 0.190 36 0.059 99. 685 0.315 0.315E-02 0.204 34 0.055 99.741 0.259 0.259E-02 0.217 18 0.029 99.770 0.230 0.230E-02 0.230 11 0.018 99.788 0.212 0.212E-02 0.243 13 0.021 99.809 0.191 0.191E-02 0.256 19 0.031 99.840 0.160 0.160E-02 0.269 14, 0.023 99.863 0.137 0.137E-02 0.282 22 0.036 99.899 0.101 0.101E-02 0.295 15 0.024 99.923 0.077 0.766E-03- 0.309 13 0.021 99.945 0.055 0.554E-03 0.322 8 0.013 99.958 0.042 0.424E-03 0.335 10 0.016 99.974 0.026 0.261E-03 0.348 6 0.010 99.984 0.016 0.163E-03 0.361 5 0.008 99.992 0.008 0.815E-04 0.374 3 0.005 99.997 0.003 0.326E-04 0.387 0 0.000 99.997 0.003 0.326E-04 0.400 0 0.000 99.997 0.003 0.326E-04 0.414 0 0.000 99.997 0.003 0.326E-04 0.427 0 0.000 99.997 0.003 0.326E-04 0.440 0 0.000 99.997 0.003 0.326E-04 0.453 0 0.000 99.997 0.003 0.326E-04 0.466 1 0.002 99.998 0.002 0.163E-04 ---------------------------------- Route Time Series through Facility Inflow Time Series File:01072dev.tsf Outflow Time Series File:01072-P2-rdout.tsf� Inflow/Outflow Analysis \aG Peak Inflow Discharge: -2.OT CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 1. CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: 6.23 Ft Peak Reservoir Elev: 397.23 Ft Peak Reservoir Storage: 48517. Cu-Ft 1. 114 Ac-Ft Flow Duration from Time Series File:01072-p2-rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % % % 0.007 38717 63.139 63.139 36.861 0.369E+00 0.020 5582 9.103 72.242 27.758 0.278E+00 0.033 4966 8.098 80.341 19.659 0.197E+00 0.046 4003 6.528 86.869 13.131 0.131E+00 0.059 3064 4 . 997 91.866 8.134 0.813E-01 0.072 2094 3.415 95.280 4.720 0.472E-01 0.085 1350 2.202 97.482 2.518 0.252E-01 0.099 820 1.337 98.819 1.181 0.118-E-01 0.112 401 0. 654 99.473 0.527 0.527E-02 0.125 29 0.047 99.521 0.479 0.479E-02 0.138 13 0.021 99.542 0.458 0.458E-02 0.151 12 0.020 99.561 0.439 0.439E-02 0.164 16 0.026 99.587 0.413 0.413E-02 0.177 24 0.039 99. 627 0.373 0.373E-02 0.190 36 0.059 99.685 0.315 0.315E-02 0.204 34 0.055 99.741 0.259 0.259E-02 0.217 18 0.029 99.770 0.230 0.230E-02 0.230 11 0.018 99.788 0.212 0.212E-02 0.243 13 0.021 99.809 0.191 0.191E-02 0.256 19 0.031 99.840 0.160 0.160E-02 0.269 14 0.023 99.863 0.137 0.137E-02 0.282 22 0.036 99.899 0.101 0.101E-02 0.295 15 0.024 99. 923 0.077 0.766E-03 0.309 13 0.021 99.945 0.055 0.554E-03 0.322 8 0.013 99.958 0.042 0.424E-03 0.335 10 0.016 99.974 0.026 0.261E-03- 0.348 6 0.010 99.984 0.016 0.163E-03 0.361 5 0.008 99.992 0.008 0.815E-04 0.374 3 0.005 99.997 0.003 0.326E-04 0.387 0 0.000 99. 997 0.003 0.326E-04 0.400 0 0.000 99.997 0.003 0.326E-04 0.414 0 0.000 99.997 0.003 0.326E-04 0.427 0 0.000 99.997 0.003 0.326E-04 0.440 0 0.000 99. 997 0.003 0.326E-04 0.453 0 0.000 99.997 0.003 0.326E-04 0.466 1 0.002 99.998 0.002 0.163E-04 ---------------------------------- Route Time Series through Facility Inflow Time Series File:01072dev.tsf Outflow Time Series File:01072-P2-rdout Inflow/Outflow Analysis Peak Inflow Discharge: 2.00 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 1.48 CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: 6.23 Ft Peak Reservoir Elev: 397.23 Ft Peak Reservoir Storage: 48517. Cu-Ft 1.114 Ac-Ft Flow Duration from Time Series File:01072-p2-rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % % % 0.007 38717 63.139 63.139 36.861 0.369E+00 0.020 5582 9.103 72.242 27.758 0.278E+00 0.033 4966 8.098 80.341 19.659 0.197E+00 0.046 4003 6.528 86.869 13.131 0.131E+00 0.059 3064 4.997 91.866 8.134 0.813E-01 0.072 2094 3.415 95.280 4.720 0.472E-01 0.085 1350 2.202 97.482 2.518 0.252E-01 0.099 820 1.337 98.819 1.181 0. 118E-01 0.112 401 0. 654 99.473 0.527 0.527E-02 0. 125 29 0.047 99.521 0.479 0.479E-02 0.138 13 0.021 99.542 0.458 0.458E-02 0.151 12 0.020 99.561 0.439 0.439E-02 0. 164 16 0.026 99.587 0.413 0.413E-02 0.177 24 0.039 99. 627 0.373 0.373E-02 0.190 36 0.059 99.685 0.315 0.315E-02 0.204 34 0.055 99.741 0.259 0.259E-02 0.217 18 0.029 99.770 0.230 0.230E-02 0.230 11 0.018 99.788 0.212 0.212E-02 0.243 13 0.021 99..809 0.191 0.191E-02 0.256 19 0.031 99.840 0.160 0.160E-02 0.269 14 0.023 99.863 0.137 0.137E-02 0.282 22 0.036 99.899 0.101 0.101E-02 0.295 15 0.024 99.923 0.077 0.766E-03 0.309 13 0.021 99. 945 0.055 0.554E-03 0.322 8 0.013 99. 958 0.042 0.424E-03 4 v 0.335 10 • 0.016 99.974 0.026 0.261E-03 0.348 6 0.010 99.984 0.016 0.163E-03 0.361 5 0.008 99.992 0.008 0.815E-04 0.374 3 0.005 99. 997 0.003 0.326E-04- 0.387 0 0.000 99.997 0.003 0.326E-04 0.400 0 0.000 99.997 0.003 0.326E-04 0.414 0 0.000 99.997 0.003 0.326E-04 0.427 0 0.000 99.997 0.003 0.326E-04 0.440 0 0.000 99.997 0.003 0.326E-04 0.453 0 0.000 99.997 0.003- 0.326E-04 0.466 1 0.002 99.998 0.002 0.163E-04 4205 148th Ave.N.E.Suite 100 COREBellevue,Washington 98007 DESIGN 425.885.7877 Fax425.885.7963 STORM DRAINAGE ANALYSIS FOR PARKSIDE COURT RENTON, WASHINGTON CfrY OF REKTON RECEIVED JUL 1 `1 2001 cUSTOMSR SERVICE cF tcAW Prepared by: Jordan R. Brown, E.I.T. , Approved by: David E. Cayton, P.E. ;f Date: July 2, 2001 �nt„ E �4 Core No.: 01072 �Ot AL Ex��es5-12— D �7 7 ENGINEERING PLANNING SURVEYING STORM DRAINAGE ANALYSIS TABLE OF CONTENTS I. Project Overview II. Existing Drainage Analysis A. Upstream Drainage B. On-Site Drainage C. Downstream Drainage Analysis III. Flow Control and Water Quality Analysis and Design A. Hydraulic Analysis B. Water Quality Calculations C. Detention Routing Calculations IV, Conveyance System Analysis and Design V. Erosion Control Calculations VI. Core and Special Requirements I. PROJECT OVERVIEW: Parkside Court is a proposed residential community consisting of 21 lots with related roadway and utilities. The project is located in Eastern Renton, north of undeveloped SE 136`h St. and east of undeveloped 146"' Ave. SE, approximately 660 feet east of 144"' Avenue SE in Renton, Washington, within the northeast quarter of Section 15, Township 23 North, Range 5 East, Willamette Meridian. See attached vicinity map. This parcel is 4.92 acres in size and slopes from northwest to southeast at an average grade of approximately 2%, with areas of maximum slope of 20%. The existing site is approximately 60% 2nd growth forest with young alder saplings, Douglas fir, western hemlock, and thick underbrush. A single-family residence, garage, gravel driveway, and grass lawn occupy the remainder of the parcel. An eastern portion of the property has been cleared to construct a drainage course to alleviate the impact of utility construction for the Maplewood Estates in the existing public right of way. The property,is bordered by the Plat of Maplewood (currently under construction) to the east, undeveloped parcels of second growth forests to the north and the south, and the Maplewood Heights Elementary School to the west. Offsite roadway improvements include two access points to be developed as non- public roadway. These will provide access to 144"' Ave. SE to the west, and to 146' Ave SE to the north. The roadways will be within the public right of way and will have stormwater catchment to convey runoff to the project water quality/detention system on site. See attached site plan for inspection. On and offsite improvement generated storm water runoff will be directed to a combination wetpond/detention pond in the southeast corner of the site. The system's point of discharge will coincide with that of the recently constructed storm drainage system in the Plat of Maplewood. The storm water detention/water quality facility is designed in accordance with the 1998 King County Storm Water Design Manual. Level Two Flow Control—stream protection criteria—is relevant to this project. • II. EXISTING DRAINAGE ANALYSIS° A. Upstream Drainage To the north of the site, there exists an offsite tributary area that constitutes a potential for flooding sections of the property line. Approximately two thirds of this tributary basin is currently drained by a culvert running west, underneath 146`'' Ave. SE to the north of the site. After site investigation, it appears that the culvert could be plugged by debris and thus backup onto the project site. To be prudent, the design of a catchment system will be employed to convey the runoff through a bypass system to the point of discharge. B. On-Site Drainage Existing storm water runoff oit-site generally sheet flows over the existing terrain in the southeasterly direction. Developed storm water runoff will generally follow the existing condition runoff characteristics. A pipe/catchbasin network will route all runoff from developed surfaces towards a wet/detention pond in the southeast corner of the site, which will outfall-to a point of discharge coincident with the Maplewood Estates storm system, which is further described in the downstream analysis. C. Downstream Drainage Analysis After comparing our knowledge in the area, we are confident that the downstream analysis described in the preliminary TIR by Barghausen Consulting Engineers is sufficient in providing for the necessary design considerations. This analysis has been excerpted as follows: The offsite analysis drainage system table lists the downstream conveyance from the site (next page). The offsite analysis drainage system table is shown pictorially on the downstream drainage map. Apparently the site is part of a much larger drainage basin contributing to the Orting Hill Ravine which consists of approximately 250 acres. Essentially the downstream drainage course from the project site sheet flows through Maplewood Park in a broad meandering swale for approximately 750 feet until discharging into a 30-inch CMP culvert which flows down 148th Place SE and 149th Place SE until reaching SE 142nd Street where it flows in an easterly direction and into a detention pond area. The discharge from the detention pond is a large channel known as the Orting Hill Ravine with the ultimate discharge point being the Cedar River. Please refer to the offsite analysis system table for a complete description of this downstream drainage course. 0 It ®� no O s a ' ;Fv i "�eTM a` a ,•1 t t go-` t r� � ��� r 3 � � rp I t" t" to � ' to t ° it = e e ; _ �,a •f ffg,� i� '� ,..r„ •{. .� ...� y I t At V' t• tc\t `\_ \E •tA \_ \S '\Y •eY q� ' f i D = � y� ` fi tY_;It tl =f.(�K� t +i"�t� Y a ,c�,r' x 1 tl Ia� • IX •1 ° ##• 9 .q r 1; y / � t e t N�t 'e e � i5, � •i� { a x•q c i a k e Y a a a g s, �ttltl i i .y ! �+� F�IS �4 '` s I\ •, •i �'13 ,i a. . I � s ! '�; q p `a I. t e= e « `» ,{ •i a .{ a ,q Y 888 657 ,\ e ' y.- i{.M t. �i D aq Y•@.�Ei k.l 0� ros T _r. _`�y, •dsroD AYE se.•...,mom � a'fT•.D Joel-,...(��� P _'�^'_. ._� S: w�,M w1 • � I I O A..�I » t} Y IDOTH AYE S[ �zt IJITN AVE 4C Y lb i � • ,� C�tn J, •I �•, t• •1'iw V k 1 I � I . ._x �^.: ;;!, roO NS �r •�.�uE, ' Y : � 3 i , h�� � r IDITN AVE SE __ �_.• r ( SE.,4-E3-5 0 0 i1 OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Basin: Cedar River Subbasin Name: Orting Hill Ravine Subbasin Number: E 5.4 R V a NZ, t ...... ..... See Map Type;-sheet flow,swale,stream, Drainage basin,vegetation,cover, % Ft Constrictions,under capacity,pouding, Tributary area,likelihood of problem, channel,pipe,pond;size,diameter, depth,type of sensitive area,volume overtopping,flooding,habitat or overflow pathways,potential impacts surface area organism destruction,scouring,bank sloughing,sedimentation,incision, other erosion I Meandering swale thru park 10:1 side slopes,5'bottom varies 0'-750' none none noted noted 2 30"CMP through several 0.66% 750'- 1,425' none none noted C13's to detention pond noted 3 Detention Pond Located within subdivision 1,425'- 1,525' none none noted noted 4 30" CMP from pond to 1.5% 1,525'-2,175' none none noted SE 142nd Street noted 5 30" CMP 2,175'-2,435' none none noted noted 6 36"CMP&Pond 2,435'-2,615' none none noted noted 7 Large steep ravine 2,615'-3,000+ Potential for erosion OFFSITE ANALYSIS DRAINAGE TABLE PER BCE 7729.005 [JPJ/bql PARKSIDE COURT CORE 01072 III. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS & DESIGN: A. Hydraulic Analysis The drainage analysis was modeled using the King County Runoff Time Series software. The onsite and upstream soils are Alderwood (AgC), KCRTS group Till. The site is located in the Seatac rainfall region with a location scale factor of 1. EXISTING CONDITIONS � NC-1 The proposed improvements cov L.4 a es. Impervious area associated with the existing single-family residence, d buildings, and gravel driveway sum to 0.79 acres. The existing pervious surfaces consist of 0.9 acres till grass and 3.71 acres of 2"d growth forest. The following information was used for generating time series and flow frequencies`. EXISTING CONDITIONS: Total Area .6 acres (01072EX) GROUND COVER AREA(acres) Till-Grass 0.90 Till-Forest 3.71 Impervious 0.79 Onsite existing conditions flow frequency analysis: PEAK FLOW RETURN (CFS) PERIOD 0.452 10 year 0.271 2 year SHEET NO. 11 KING COUNTY AREA, WASHINGTON (RENTON QUADRANGLE) 10, 1 680 000 FEET 1220 713011 �7l. Y7o�ni 6 •' , - � •• AgD � u Ic u o "Agc. °413� AgC•��• •Btd AgB .8 ° Trailer +: i.Eu6 •® . arkl•` 'iiBM• BI; . a- r-----ti' �i 3 " 424 �16 ----- it •eenwoodTCa I ••� .. I ' — o I 180 000 EET I F AgC \\ j •406I .r. An \\ o� .I PARK SIDE 1 °\ a c .. •1 g IN I COURT LU s I � AkF 1 BM 37 EvB 'I vE ji, Py EvB / � • o,SP I �\• / AkF J. it- Rh o o ° Py Ma ,�, c\� QG .r •.y \\ If.. AkF g Py I • PC m r\..\ It C M .Py 'u El lOt Puj c• •Rh W u I u Ji. Py AkF �\\ �c�'- r z. � �) f A C \\\ AkF Park Ng s g n I o� Py .. AgC EvC M I,B AgD AkF 0 20-7 ,. S.° A gM n - --- --�-B a� 6 27 30 ( I I - P Age AgD AgC I AgD I AkF B 428 Mo l O I KC SOILS MAP - IFS �\ � I I AgB 1 m6 AgB _ __PIPELINE ' Agc PARKSIDE COURT I � I 27 ' 2 --- CORE 01072 492No f DEVELOPED CONDITIONS The developed site will consist of 21 single-family residences with associated roadway and utilities. The design of the detention system will assume the maximum potential of impervious surface, as described in the 1998 King County Surface Water Design Manual. The maximum impervious area per lot was calculated using the 1998 KCSWDM criteria on page 3-28. The proposed development is urban residential. The site is R-5 zoning. Therefore, the impervious coverage is assumed as 48% of the lot area. The total lot area as stated in the preliminary plat is 4.04 acres. Therefore, the total impervious cover on the lots is 1.93 acres. cm- sili IMPERVIOUS AREA DELINEATION: Onsite road and sidewalk 59,730 sf f 4. 3-4 pc, Impervious area of lots (4,022 sf*21 lots) 84,472 sf —� • Total impervious area 144,202 sf(3.03 acres) 3. \ 31 �C' ---7 tA .0 • The input used for the KCRTS analysis is summarized in the table below: DEVELOPED CONDITIONS: Total Area 4.63 acres (01072DEV) GROUND COVER AREA(acre) Till-Grass (Landscaping) 2.10 Impervious 3.30 Onsite developed conditions flow frequency analysis: PEAK FLOW RETURN (CFS) PERIOD 1.19 10 year e4-9' 0.99 2 year • B. Water Quality Volume Calculations • Based on the location of the site, "Basic Water Quality Treatment' is required as shown on the King County Water Quality Map on the following page. The permanent storage portion of the wetpond will satisfy this requirement. The required volume of dead storage will be designed per KCSWDM Section 6.4.1.1. The following variables were used in the calculation: • Volume Factor(f) = 3 • Rainfall = 0.039 feet, per Figure 6.4.1.A, KCSWDM • Where A; = area of impervious surface (so Atg= area of till soil covered with grass (so Atf= area of till soil covered with forest (so A.= area of outwash soil covered with grass or forest (so • Vr=[0.9A; 4- 0.25Atg+ 0.1 Atf+ 0.01 A j x (R/12) • Vr=[(0.9)(3.3) + (0.25)(2.1)]0.039 x (43560sf/ac)= 5,937 CF • Vb = f*Vr= 3(5,937) = 17,812 CF The first cell will carry 4,883 CF. The second cell will carry 13,539 CF. Therefore, the total dead storage is 18,422 CF, which exceeds the required volume. See volume calculation spreadsheet on the following pages. The first cell is designed to allow for a minimum depth of 1 foot for sediment storage. i =.:s x ,g r 'E.�' �. a• x•L1, ,s.- ':s:� r, - k:..'n /, ^t" YiFvi Sk w -a.q tr�n.t,rr 'p J :':pt a•.+k ,i'�.i't.- 'L .--;';SVj ,k..�f--. ,-. y. �." , ..,s..',. 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"A :e y lYy� JtnF _ _�... :...:>w, +s # •.„. &r _ ,....,4..- ,.. „,... F IP' "r .,a.,. ,,.:.� ,:. .. - `:,. „�a.: es ,,--.,, .,-,r L •.a,r' {av1 s .e l: _ - s - :� ....,.'sue tr �.,i.,.3.A. `n •.. w!...� .• :.,r„ �_ .rT. .+_.� ^t s,.,.,. :.,L,:ek.:a 5,. .n „sz' r' 1 - n5m. - � ��,.<„-<.w„-.H ,�"hw ,•`J_�b' .. ., .- .d^'. <.." Y. i.,.-y `f, h t�s,._.,.F %B`W e.. 531��V,^�"'Lyh :1� - '+la � t'� T§,.. .X C. Detention Routing Calculations • The site area is represented on the King County Flow Control Applications Map as Flow Control Level 2. The detention/water quality facility will be a combination water quality and detention pond. The pond will be designed according to the 1998 KCSWDM, using level 2 flow control criteria. The pond (0 1 072POND.RDF) was sized based on the 1998 KCSWDM and KCRTS Computer Software Reference Manual. Program output referencing the results of the sizing routine is included following this section. The control structure has two orifices to meet the detention criteria to match the KCRTS flow duration curves of the existing and developed conditions. The first orifice has a diameter of 1.43 inches, The second orifice is at a stage of 3.6 feet with a diameter of 2.40 inches. The primary overflow for the pond is the riser pipe within the control structure. The KCRTS program calculates the overflow over the riser when routing the hydrographs through the detention facility. This is evidenced by the fact that the riser stage is 6 feet and the-maximum stage of the detention pond is 6 feet for the design flows. This translates to a maximum water surface of 397.00. Stormwater flows in excess of the capacity of the control structure riser will overflow through an emergency overflow route that was established by design of a spillway lined with riprap that will direct runoff into the existing stream channel. The primary overflow elevation is EL 397.0 (shown as design maximum water surface on the plans). The secondary overflow flow elevation is EL 397.5 (shown as overflow elevation on the plans) which will also be the top of the riprap of the emergency overflow spillway. The required spillway length is calculated per KCSWDM section 5.3.1.2 as follows: Length of Spillway: L= (Q100/Q.21H3/z)) - (2.4H) _ (2.00/(3.21(0.2)"2)) - (2.4(0.2)) = 6.48' (Use 6.5') Q100 = 2.00 cfs (tributary to pond), Assume H=0.2'(minimum value) kr� •y'tu ,� $� !'a�� � �C€�6��sl;� ° c r '�' StF F�ti � .a.' 3� a"' try .7 , _ 'sh � 7�`,°. @@`""µz��a :�^s` W $n +, t< 'fg ,V3�hc� � .` ^. �•� '3 �s • fy���c'��gyr'� .f is '�..', e -,.�,��,�� a k. V g•.i' 3 ?n�!¢_. } Ky ¢"�''_ rS §r <�p`k Rfa R y �,; YI -.. VZ w 1: e,,:� Y'a• � a ✓:. 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Rip :r G^ � _ `M���,�, ` 4• %d«.: Y�P,,� � ar,.• s `�t�' t: r5 '���' � 4,°� 1 �{4�' :� � 7G k� iri �,•. tp a �ps.: •x h a$:c s ��k� � . ?_ �+�. 451:d 7� e q `� {" & ;��-sa 1{ t�� e � � "Pyr ; '' ,y�" .,,x� � � 3 �a ¢ � � J Sl S-q .r,, -�+.3-1 d•s A w �a 'ti w"�i ^� 'h. +✓. •..:� :ry� Gi. 4� �f� r z..e WY y"'� � �'y f rk�A' `,:. ,.5. , ': ze PARS Il9E 'ze. - r }� ,^f.6 t '. f� y COURT rp �. ��'„ �`�. -��{��tt- `- •w t'� l 3 :� > � v�. �? x� '}yam,,' y' '-a. 4 3- '# '� '' a �*�'� ir"`j E u �� �'d � pu � 5"' `'" d x�� �3+a'�,`'73'�,y'r>r���(�k � _ y"F� :h,4. d• v�# r �., � �l :1i 7� ���. ��5 �s 3 �.. +s r ��,y2 ;a•Fp. :f u� w ;"l•.�:hT,.:.•.emu•Sxx a t - ,.'x ..!-a KCSWDM FLOW CONTROL. MAP PARKSIDE COURT ASN " CORE 01072 -..1k �_���' sq '.�k' has K•.....: �t't; .� r 01072ex Flow Frequency Analysis Time Series File : 01072ex. tsf Project Location: Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------ FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0 . 445 4 2/09/01 15 : 00 0 . 8.29 1 100 . 00 0 . 99 0 0 . 270 7 1/05/02 16 : 00 0 .480 2 25 . 00 0 . 96 0 0 . 480 2 2/27/03 7 : 00 0 .452 3 10 . 00 .0 . 90 0 . 214 8 8/26/04 2 : 00 0 .445 4 5 . 00 0 . 80 0 0 .271 6 1/05/05 8 : 00 0 .410 5 3 . 00 0 . 66 7 0 .452 3 1/18/06 16 : 00 0 . 271 6 2 . 00 0 . 50 0 —- ----------- - ----- 0 .410 5 11/24/06 3 : 00 0 . 270 7 1 . 30 0 . 23 1 '- 0 . 829 1 1/09/08 6 : 00 0 . 214 8 1 . 10 0 . 09 • 1 Computed Peaks 0 . 713 50 . 00 0 . 98 0 Page 1 KCRTS TIME SERIES OUTPUT PARKSIDE COURT CORE 01072 01072dev Flow Frequency Analysis Time Series File: 01072dev. tsf Project Location: Sea-Tac - --Annual Peak Flow Rates--- -----Flow Frequency Analysis------ FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0 . 988 6 2/09/01 2 : 00 2 . 00 1 100 . 00 0 . 99 0 0 . 801 8 1/05/02 16 : 00 1 . 25 2 25 . 00 0 . 96 0 1 . 19 3 2/27/03 7 : 00 1. 19 3 10 . 00 0 . 90 p -- 0 . 861 7 8/26/04 2 : 00 1. 05 4 5 . 00 0 . 80 0 1 . 04 5 10/28/04 16 : 00 1 . 04 5 3 . 00 0 . 66 7 1 . 05 4 1/18/06 16 : 00 0 . 988 6 2 . 00 0 . 50 0 1 . 25 2 10/26/06 0 : 00 0 . 861 7 1 . 30 0 . 23 1 -- 2 . 00 1 1/09/08 6 : 00 0 . 801 8 1 . 10 0 . 09 1 Computed Peaks 1. 75 50 . 00 0 . 98 0 s Page 1 Retention/Detention Facility ' Type of Facility: Detention Pond Side Slope: 2.00 H:1V Pond Bottom Length: 110.00 ft Pond Bottom Width: 50.00 ft Pond Bottom Area: 5500. sq. ft Top Area at 1 ft. FB: 10764. sq. ft 0.247 acres Effective Storage Depth: 6.00 ft ,1 Stage 0 Elevation: 391.00 ft- �� A, jS � Storage Volume: 45672. cu. ft 1.048 ac-ft Riser Head: 6.00 ft Riser Diameter: 12.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 1.43 0.136 2 3. 60 2.40 0.242 6.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation Surf Area (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft) 0.00 391.00 0. 0.000 0.000 0.00 5500. 0.01 391:01 55. 0.001 0.007 0.00 5506. 0.03 391.03 165. 0.004 0.010 0.00 5519. 0.04 391.04 221. 0.005 0.012 0.00 5526. 0.06 391.06 331. 0.008 0.014 0.00 5538. 0.07 391.07 387. 0.009 0.015 0.00 5545. 0.09 391.09 498. 0.011 0.017 0.00 5558. 0.10 391.10 553. 0.013 0.018 0.00 5564. 0.12 391.12 665. 0.015 0.019 0.00 5577. 0.22 391.22 1226. 0.028 0.026 0.00 5642. 0.32 391.32 1793. 0.041 0.031 0.00 5706. 0.42 391.42 2367. 0.054 0.036 0.00 5772. 0.52 391.52 2947. 0.068 0.040 0.00 5837. 0. 62 391.62 3534. 0.081 0.044 0.00 5903. 0.72 391.72 4128. 0.095 0.047 0.00 5969. 0.82 391.82 4728. 0.109 0.050 0.00 6036. 0. 92 391.92 5335. 0.122 0.053 0.00 6102. 1.02 392.02 5949. 0.137 0.056 0.00 6169. 1.12 392.12 6569. 0.151 0.059 0.00 6237. 1.22 392.22 7196. 0.165 0.061 0.00 6305. 1.32 392.32 7830. 0.180 0.064 0.00 6373. 1.42 392.42 8471. 0.194 0.066 0.00 6441. 1.52 392.52 9118. 0.209 0.068 0.00 6510. 1. 62 392.62 9773. 0.224 0.071 0.00 6579. 1.72 392.72 10434. 0.240 0.073 0.00 6648. 1.82 392.82 11102. 0.255 0.075 0.00 6718. 1.92 392.92 11777. 0.270 0.077 0.00 6788. 2.02 393.02 12460. 0.286 0.079 0.00 6858. KCRTS POND OUTPUT PARKSIDE COURT CORE 01072 2.12 393. 12 13149. 0.302 0.081 0.00 6929. 2.22 393.22 13845. 0.318 0.083 0.00 7000. 2.32 393.32 14549. 0.334 0.085 0.00 7071. 2.42 393.42 15260. 0.350 0.086 0.00 7143. 2.52 393.52 15977. 0.367 0.088 0.00 7214. 2.62 393.62 16703. 0.383 0.090 0.00 7287. 2.72 393.72 17435. 0.400 0.092 0.00 7359. 2.82 393.82 18174. 0. 417 0.093 0.00 7432. 2.92 393.92 18921. 0.434 0.095 0.00 7505. 3.02 394.02 19675. 0.452 0.097 0.00 7579. 3.12 394.12 20437. 0.469 0.098 0.00 7653. 3.22 394 .22 21206. 0.487 0.100 0.00 7727. 3.32 394.32 21982. 0.505 0.101 0.00 7801. 3.42 394.42 22766. 0.523 0.103 0.00 7876. 3.52 394.52 23558. 0.541 0.104 0.00 7951. 3.60 394. 60 24196. 0.555 0.105 0.00 8011. 3.63 394.63 24437. 0.561 0.107 0.00 8034. 3.65 394. 65 24598. 0.565 0.112 0.00 8049. 3.68 394.68 24839. 0.570 0. 120 0.00 8072. 3.70 394.70 25001. 0.574 0.130 0.00 8087. 3.73 394.73 25244. 0.580 0.143 0.00 8110. 3.75 394.75 25406. 0.583 0.159 0.00 8125. 3.78 394.78 25650. 0.589 0.173 0.00 8148. 3.80 394.80 25813. 0.593 0.178 0.00 8163. 3.90 394. 90 26634. 0. 611 0. 195 0.00 8239. 4.00 395.00 27461. 0. 630 0.210 0.00 8316. 4.10 395.10 28297. 0.650 0.223 0.00 8393. 4.20 395.20 29140. 0. 669 0.235 0.00 8470. 4.30 395.30 29991. 0. 688 0.246 0.00 8548. 4.40 395.40 30850. 0.708 0.256 0.00 8626. 4.50 395.50 31716. 0.728 0.266 0.00 8704. 4.60 395. 60 32590. 0.748 0.275 0.00 8783. 4.70 395.70 3347-3. 0.768 0.284 0.00 8861. 4.80 395.80 34363. 0.789 0.293 0.00 8941. 4.90 395.90 35261. 0.809 0.301 0.00 9020. 5.00 396.00 36167. 0.830 0.309 0.00 9100. 5.10 396.10 37081. 0.851 0.317 0.00 9180. 5.20 396.20 38003. 0.872 0.324 0.00 9261. 5.30 396.30 38933. 0.894 0.332 0.00 9341. 5.40 396.40 39871. 0. 915 0.339 0.00 9423. 5.50 396.50 40817. 0. 937 0.346 0.00 9504. 5.60 396. 60 41772. 0. 959 0.352 0.00 9586. 5.70 396.70 42734. 0. 981 0.359 0.00 9668. 5.80 396.80 43705. 1.003 0.366 0.00 9750. 5. 90 396.90 44685. 1.026 0.372 0.00 9833. 6.00 397.00 45672. 1.048 0.378 0.00 9916. 6.10 397.10 46668. 1.071 0. 692 0.00 9999. 6.20 397.20 47672. 1.094 1.260 0.00 10083. 6.30 397.30 48684. 1.118 2.000 0.00 10167. 6.40 397.40 49705. 1. 141 2.790 0.00 10251. 6.50 397.50 50735. 1.165 3.080 0.00 10336. 6.60 397. 60 51773. 1.189 3.340 0.00 10421. 6.70 397.70 52819. 1.213 3.580 0.00 10506. 6.80 397.80 53874. 1.237 3.810 0.00 10592. 6.90 397. 90 54937. 1.261 4 .020 0.00 10678. 7.00 398.00 56009. 1.286 4.220 0.00 10764. 7.10 398.10 57090. 1.311 4 .410 0.00 10851. 7.20 398.20 58179. 1.336 4.590 0.00 10937. 7.30 398.30 59278. 1.361 4.760 0.00 11025. 7.40 398.40 60384 . 1.386 4. 930 0.00 11112. 7.50 398.50 61500. 1.412 5.090 0.00 11200. 7.60 398. 60 62624. 1.438 5.250 0.00 11288. 7.70 398.70 63758. 1.464 5.400 0.00 11377. 7.80 398.80 64900. 1.490 5.550 0.00 11465. 7.90 398. 90 66051. 1.516 5.690 0.00 11555: 8.00 399.00 67211. 1.543 5.830 0.00 11644. Hyd Inflow Outflow Peak Storage n9s 6e14' Target alc Stage Elev (Cu-Ft) (Ac-Ft) 1 2.00 ******* ti 51 6.23 397.23 48013. 1.102 W � 2 0.99 0.4 6.02 397.02 45903. 1.054 3 0.99 ******* 0.35 5.53 396.53 41086. 0.943 4 1.05 ******* �gV0.31 5.05 396.05 36667. 0.842 y,) ((o �5 1.19 ******* Q' 0.29 4.76 395.76 33994. 0.780�- 6 0.62 ******* 0.21 4.00 395.00 27496. 0. 631 7 0.80 ******* 0.10 3.38 394.38 22463. 0.516 8 0.86 ******* 0.09 2.72 393.72 17423. 0.400 ---------------------------------- Route Time Series through Facility Inflow Time Series File:01072dev.tsf Outflow Time Series File:01072rdout Inflow/Outflow Analysis Peak Inflow Discharge: 2.00 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 1.51 CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: Peak Reservoir Elev: 397.23 FtFt Peak Reservoir Storage: i. Cu-Ft t� _ 1.102 Ac-Ft Flow Duration from Time Series File:01072rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % o % 0.006 38777 63.237 63.237 36.763 0.368E+00 0.019 5316 8.669 71. 906 28.094 0.281E+00 0.032 4829 7.875 79.781 20.219 0.202E+00 0.044 3797 6.192 85. 974 14.026 0.140E+00 0.057 3232 5.271 91.244 8.756 0.876E-01 0.070 2152 3.509 94.754 5.246 0.525E-01: 0-.082 1368 2.231 96. 985 3.015 0.302E-01 0.095 949 1.548 98.532 1.468 0.147E-01 0.108 566 0.923 99.455 0.545 0.545E-02 0.120 35 0.057 99.512 0.488 0.488E-02 0.133 17 0.028 99.540 0.460 0.460E-02 0.146 15 0.024 99.565 0.435 0.435E-02 0.158 8 0.013 99.578 0.422 0.422E-02 0.171 17 0.028 99. 605 0.395 0.395E-02 0.184 21 0.034 99.640 0.360 0.360E-02 0.196 37 0.060 99.700 0.300 0.300E-02 0,209 30 0.049 99,749 0.251 0.251E-02 0.222 16 0.026 99.775 0.225 0.225E-02 0.234 11 0.018 99.793 0.207 0.207E-02 0.247 12 0.020 99%812 0.188 0.188E-02 0.260 17 0.028 99.840 0.160 0.160E-02 0.272 14 0.023 99.863 0.137 0.137E-02 0.285 18 0.029 99.892 0.108 0.108E-02 0.298 18 0.029 99.922 0.078 0.783E-03 0.310 10 0.016 99.938 0.062 0.620E-03 0.323 9 0.015 99. 953 0.047 0.473E-03 0.336 7 0.011 99. 964 0. 036 0.359E-03 0.348 9 0.015 99. 979 0.021 0.212E-03 0.361 4 0.007 99. 985 0.015 0.147E-03 0.374 5 0.008 99.993 0.007 0.652E-04 0.386 2 0.003 99.997 0.003 0.326E-04 0.399 0 0.000 99.997 0.003 0.326E-04 0.412 0 0.000 99.997 0.003 0.326E-04 0.424 0 0.000 99.997 0.003 0.326E-04 0.437 0 0.000 99. 997 0.003 0.326E-04 0.450 1 0.002 99. 998 0.002 0.163E-04 STORM WATER DETENTION POND VOLUME CALCULATIONS PROJECT NAME: PARKSIDE COURT 01072 BY: JRB ELEVATION INCREMENTAL TOTAL LIVE VOLUME VOLUME VOLUME SF CF CF CF 386.0 1,720 2,226 387.0 2,732 SV2,226 3,006 388.0 3,280 5,232 7,960 , 390.0 4,680 13,192 5,230 391.0 5,780' 18,422 (NWS 391.0 6,210 392.0 6,640 24,632 6,21.0 15,000 394.0 8,360 39,632 21,210 RON"Ill 18,560 396.0 10,200 , 58,192 39,770 10,660 ,, m 397.0 11,120 68,8521 50,430 DESIGNED REQUIRED PERMANENT/WQ VOLUME (CF) : 18,422 17,812 LIVE STORAGE VOLUME (CF) : 50,430 , 48,013 SIV.CONVEYANCE SYSTEM ANALYSIS AND DESIGN: The conveyance system for the site was designed for both the 25-year, 24-hour storm, and the 100-yr, 24-hour design storm. A conveyance spreadsheet was generated for the 25- year storm using the rational method to calculate flows for each area collected by each catch basin. The precipitation rate for the 25-year, 24-hour storm is 3.46 inches. The precipitation rate for the 100-year, 24-hour storm is 3.9 inches. A weighted C value for the rational method was used for each area collected by each catch basin. The average C value for the developed site per KCSWDM 3.2.1 is (2.10*0.25 + 3.30*0.90)/5.40 = 0.65. The attached Storm Conveyance spreadsheet shows that no pipe segment in this design will contain flows that exceed their capacity for either the 25-year or 100-year storm events. Therefore, backwater calculations were not necessary. i1 s.;:i r. ;. - ,£ e .>§ 2- •p ,z § ; s. �. c_... .:r3' ,.»Q , .:" 'n �� -, ,��..« .tee �a'",�,::. , .x a:, 1•�a^��f` NIL IYCRFJYFWAL RUNOFF IIIPIRVIOUS TIME OE RAINFALL TRIBUTARY PPE PPE PIPE ACTUAL TRAVEL PIPE CAPACITY SUNMARY PPE SEGNINT AREA COEFFUW AREA SUM OF GONG. INTENSITY ROW MAN ING'S MANIETER SLOPE LENGTH VELOCITY IM Q[FULII VUM Q[ACTI/Q[Flllll FROM CB TO CB (ACRES) "C" [A*Cl (A*Cl [MWUTESI UNW (CFSI W (NYCHES) (PERCENT] CHI] IFT/SECT UYINTTESI [CFSI [FT/SECI [PERCENT] +11 2 '' # a,. 3;aC' .y Y.ak '...I '.e F #Fs..•sr 6 9 c. -'� tx a. 's' r 23 22 0.27 0.65 0.177 k 0.177 10.00 2.39 0.423 0.012 12 0.50 282 2.42 1.95 2.729 3.47 15.5% 22 21 0.19 0.65 0.122 ►L 0.299 11.95 2.13 0.638 0.012 12 0.50 32 2.78 0.19 2.729 3.47 23.4% 21 20 0.14 0.65 0.090 4 0.389 12.14 2.11 0.822 0.012 12 0.50 25 3.02 0.14 2.729 3.47 30.1% 20 19 0.02 0.65 0.013 0.402 12.28 2.10 0.843 0.012 12 0.50 282 3.02 1.55 2.729 3.47 30.9% 19 18 0.17 0.65 0.112 0.514 13.83 1.95 1.001 0.012 12 0.50 204 3.18 1.07 2.729 3.47 36.7% 18 17 0.13 0.65 0.087 0.601 14.90 1.86 1.116 0,012 12 0.50 125 3.27 0.64 2.729 3.47 40.9% 17 8 0.46 0.65 0.298 0.899 15.54 1.81 1.626 0.012 12 0.50 57 3.61 0.26 2.729 3.47 59.6% 16 15 0.10 0.65 0.064 0.064 10.00 2.39 0.154 0.012 12 0.50 198 1.75 1.88 2.729 3.47 5.6% 15 14 0.04 0.65 0.029 0.093 11.88 2.14 0.199 0.012 12 0.50 199 1 1.96 1.69 2.729 3.47 7.3% 14 13 0.05 0.65 0.030 0.124 13.57 1.97 0.243 0.012 12 0.50 162 2.05 1.32 2.729 3.47 8.9% 13 12 0.10 0.65 0.064 0.188 14.89 1.86 1 0.349 0.012 12 0.50 38 2.31 0.27 2.729 3.47 12.8% 12 11 0.24 0.65 0.157 0.345 15.16 1.84 0.633 0.012 12 0.50 29 2.78 0.17 2.729 3.47 23.2% 11 10 0.18 0.65 0.116 0.461 15.33 1.82 0.841 0.012 12 2.00 203 4.83 0.70 5.458 6.95 15.4% 10A 10 0.81 0.65 0.525 0.525 16.04 1.77 0.931 0.012 12 1.00 29 1 4.03 0.12 3.860 4.91 24.1% 10 9 0.78 0.65 0.505 1.492 16.16 1.76 2.631 0.012 12 1.60 191 6.28 0.51 4.882 6.22 53.9% 9A' 9 - 0.80 0.65 0.518 0.518 16.66 1.73 0.896 0.012 12 1.00 29 3.93 0.12 3.860 4.91 23.2% 9 8 " 0.59 0.65 0.383 3.292 16.79 1.72 5.669 0.012 1 12 5.28 109 11.91 0.15 8.869 11.29 63.9% 6A 6 0.92 0.42 0.386 0.386 10.00 2.39 0.920 0.012 12 40.00 5 13.36 0.01 24.411 31.08 3.8% 6 5 0.00 0.65 0.000 0.386 10.01 2.39 0.920 0.012 12 0.50 53 3.08 0.29 2.729 3.47 33.7% 5 4 0.00 0.65 0.000 0.386 10.29 2.34 0.904 0.012 12 1.20 185 0.00 0.00 4.228 5.38 21.4% 4 3 0.00 0.65 0.000 0.386 10.29 2.34 0.904 0.012 12 4.00 35 6.19 0.09 7.719 9.83 11.7% 3 2 0.00 0.65 0.000 0.386 10.39 2.33 0.899 0.012 12 3.30 98 5.94 0.28 7.012 8.93 12.8% 2 1 FROM CB8 0.65 0.000 3.678 10.66 2.29 8.429 0.012 18 0.50 48 5.19 0.15 8.047 4.55 104.7% 1 IA FR:MAPLEWOOD 0.65 0.000 34.462 10.82 2.27 78.265 0.012 30 4.00 20 20.46 0.02 88.870 18.10 88.1% 7/11/01 CORE DESIGN, INC. 1 Nor ' 4 a. M rE. PICRONENTAL BMW IVPERVRRIS THE OF RAWFALL TRRRRARY PPE PPE PPE ACTUAL TRAVEL PPE CAPACITY SUMMARY PPE SEGIIIENT AMD AREA COEFRCFNT AREA SUM OF CONC. INTENSITY FLOW MANNRCG'S DIAMETER SLOPE LENGTH VELOCITY TYYE Q[FUII V(FULII Q[ACTI/Q[RILL) FROM CB TO CB [ACRES) "C" [A*Cl [A*Cl VMNUTESI ON/IRII [CFSI "n" WES] MCENTI MET) (FT/SECT UMNUTESI (CFSI [FT/SECT [PERCENT) a 7 23 22 0.27 0.65 0.177 0.177 10.00 2.02 0.359 0.012 12 0.50 282 2.31 2.03 2.729 3.47 13.2% 22 21 0.19 0.65 0.122 0.299 12.03 1.80 0.537 0.012 12 0.50 32 0.00 0.00 2.729 3A7 19.7% 21 20 0.14 0.65 0.090 0.389 12.03 1.80 0.698 0.012 12 0.50 25 2.85 0.15 2.729 3.47 25.6% 20 19 0.02 0.65 0.013 0.402 12.18 1.78 0.716 0.012 1 12 0.50 282 2.92 1.61 2.729 3.47 26.2% 19 18 0.17 0.65 0.112 0.514 13.79 1.64 0.845 0.012 12 0.50 204 3.02 1.12 2.729 3.47 31.0% 18 17 0.13 0.65 0.087 0.601 14.91 1.56 0.938 0.012 12 0.50 125 3.13 0.67 2.729 3.47 34.4% 17 8 0.46 0.65 0.298 0.899 15.58 1.52 1.365 0.012 12 0.50 57 3.47 0.27 2.729 3.47 50.0% 16 15 0.10 0.65 0.064 0.064 10.00 2.02 0.131 0.012 12 0.50 198 1.65 2.00 2.729 3.47 4.8% 15 14 0.04 0.65 0.029 0.093 12.00 1.80 0.167 0.012 12 0.50 199 1.88 1.77 2.729 3.47 6.1% 14 13 0.05 0.65 0.030 0.124 13.77 1.64 0.203 0.012 12 0.50 162 1.96 1.38 2.729 3.47 7.4% 13 12 0.10 0.65 0.064 0.188 15.14 1.55 0.291 0.012 12 0.50 38 2.19 0.29 2.729 3.47 10.7% 12 11 0.24 0.65 0.157 0.345 15.43 1.53 0.527 0.012 12 0.50 29 0.00 0.00 1 2.729 3.47 19.3% 11 10 0.18 0.65 0.116 0.461 15.43 1.53 0.705 0.012 12 2.00 203 4.62 0.73 5.458 6.95 12.9% 101A 1Q 0.81 0.65 0.525 0.525 16.16 1.48 0.778 0.012 12 1.00 29 0.00 0.00 3.860 4.91 20.2% 10 9 0.78 0.65 0.505 1.492 16.16 1.48 2.210 0.012 12 1.60 191 6.00 0.53 4.882 6.22 45.3% 9Ai 9 0.80 0.65 0.518 0.518 16.69 1.45 0.752 0.012 12 1.00 29 0.00 0.00 3.860 4.91 19.5% 9 8 0.59 0.65 0.383 3.292 16.69 1.45 4.777 0.012 12 5.28 109 11.41 0.16 8.869 11.29 53.9% 6A 6 0.92 0.42 0.386 0.386 10.00 2.02 0.781 0.012 12 40.00 5 13.36 0.01 24.411 31.08 3.2% 6 5 0.00 0.65 0.000 0.386 10.01 2.02 0.781 0.012 12 0.50 53 2.97 0.30 2.729 3.47 28.6% 5 4 0.00 0.65 0.000 0.386 10.30 1.99 1 0.766 0.012 12 1.20 185 0.00 0.00 4.228 5.38 18.1% 4 3 0.00 0.65 0.000 0.386 10.30 1.99 0.766 0.012 12 4.00 35 5.95 0.10 7.719 9.83 9.9% 3 2 0.00 0.65 0.000 0.386 10.40 1.97 0.761 0.012 12 3.30 98 5.62 0.29 7.012 8.93 10.9% 2 1 FROM CB8 0.65 0.000 3.678 10.69 1.94 7.130 0.012 18 0.50 48 5.15 0.16 8.047 4.55 88.6% 1 IA FR:MAPLEWOOD 0.65 0.000 34.462 10.85 1.92 66.182 0.012 30 4.00 20 1991. 0.02 88.870 18.10 74.5% 7/11/01 CORE DESIGN, INC. I V. EROSION CONTROL CALCULATIONS The intent of this erosion and sedimentation control plan is to minimize erosion and the transport of construction related sediments off-site. This design will utilize interceptor swales and ditches to route all runoff originating from disturbed areas of the site to the permanent drainage facility, modified with the necessary erosion control measures. The sedimentation control facilities were designed using the methodology as presented in Chapter 5 of the KCSWDM. This plan will also include constructing temporary filter fabric fencing along the south and east property lines and the placing of mulch, straw, chips or hydro-seeding on all disturbed areas which will be exposed during the wet season as required, see plan sheet C2.31, note 7. Design of the erosion/sedimentation control plan was completed in conformance with • Core Requirement #5 per the 1998 KCSWDM. Compliance with the 7 minimum requirements are summarized below. 1. Clearing Limits: Clearing Ihnits have been delineated on sheet C2.01 of the civil 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 C2.01 of the civil plans specify specific times at which temporary and permanent cover measures will be installed. 3. Perimeter Protection: Per sheet C2.01 of the civil plans, 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 be installed at the entrance to ithe project site. 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 1998 KCSWDM Appendix D. Erosion Control Calculations The flows used will be assumed the same as those for the developed condition. TESC Pond: Pond Geometry: • 2:1 interior side slopes • 5.0' depth The bottom of the TESC pond (excluding sediment storage) is EL 391.0 in the first • and second cell. Therefore, the depth of water is 396.0—391.0= 5 ft> 3.5 ft=> OK. Surface Area: • Tributary area= 5.4 acres • Design flow, Q2= 0.99 cfs (see attached basin summary 0 1 072DEV.PKS) • SA= 2 x Q2/0.00096 = 2,059 sf(required at top of riser) • Side slopes =2:1 • Depth of live storage= 5' • Surface area at top of riser= 10,200 sf=:> OK • Riser: Designed capacity to accommodate: Design flow, Q,o= 1.19 cfs (see attached basin summary 01072DEV.PKS) Flow capacity for 12" diameter riser with 1 foot of head ;::� 8 cfs (see attached Fig. 5.3.4.H) • Emergency Overflow Spillway Length of Spillway: L= (QIod(3.21H"2)) - (2.4H) Q100 =2.00 cfs (tributary to pond) Assume H = 0.2'(minimum value) L= (2.00/(3.2l(0.2)3/2)) - (2.4(0.2)) = 6.48' (Use 6.5') • Dewatering Orifice: Designed per KCSWDM D.4.5.2: Orifice area= [As(2h)0-5] / [(0.6)(3600)Tg1.5] _ (10,200)(2*5)0-5/(0.6)(3600)(24)(32.2)0.5 = 0.120 SF Orifice diameter=24(orifice area/n)o =24(0.120/7t)o.s = 4.48 in. The TESC pond will be constructed so as to locate the orifice at the elevation of the normal water surface in final pond design, el. 391.0. The temporary standpipe riser will extend to elevation 396.0-1.5ft below the emergency spillway. SECTION 5.3 DETENTION FACILITIES Riser Overflow The nomograph in Figure 5.3.4.H can be used to determine the head (in feet) above a riser of given diameter and for a given flow(usually the 100-year peak flow for developed conditions). FIGURE 5.3.4.11 RISER INFLOW CURVES 100 I 72 54 48-' I I I I 42 36 � I 33 _ , 30 2 f 7 24 0 0000001, s 1=o,-- eoI ) t 21 c L40000K W I , d 18 N O000, . � 1 I 10 15 W 1 I s O s 12 00010 }! 10 04 i 0.1 i i 1 HEAD IN FEET (measuIred from crest of riser) 10 Qw.;r=9.739 DH311 • z iiz Q or(Hoe=3.782 D H Q in cfs, D and H in feet Slope change occurs at weir-orifice transition 9/1/98 RISER CAPACITY CURVES 5-50 PARKSIDE COURT CORE 01072 • VI. CORE AND SPECIAL REQUIREMENTS Included herein are the analyses of the seven Core requirements and 12 Special requirements pertaining to this development per the 1998 KCSWDM. These requirements have been investigated as part of the preliminary TIR furnished by Barghausen Consulting Engineers dated 4/13/2001. These findings are considered sufficient for the evaluation of prudent design considerations and included on the attached pages. • 2.0 ANALYSIS OF SEVEN CORE REQUIREMENTS Core Requirement No.1-Discharge at the Natural Location: The discharge from a proposed project site must occur at the natural location. Response: This project proposes discharge at the natural location in accordance with Core Requirement No. 1. No diversion of runoff will be allowed at the development of this project. Core Requirement No. 2 - Off-Site Analysis: All proposed projects must identify the upstream tributary drainage area and perform a downstream analysis. Levels of analysis required depend on the problems identified or predicted. At a minimum a Level 1 Analysis must be submitted with the initial permit application. Response: This drainage report incorporates a Level 1 Downstream Analysis, Please refer to that document for fulfillment of this requirement. Core Requirement No.3-Flow Control: Proposed projects must provide runoff controls to limit the developed conditions,peak rates of runoff to the pre-development of peak rates for specific design storm events based on the runoff from defined existing site conditions and install biofiltration measures. Response: This project proposes to provide Level 2 Flow Control,which is a duration matching standard based on KCRTS methodology as delineated in the 1998 King County, Washington Surface Water Design Manual. This project proposes a wetidetention pond as a means of runoff treatment. Core Requirement No.4-Conveyance System: All conveyance systems for proposed projects must be analyzed, designed and constructed for existing tributary off-site runoff and developed on-site runoff from the proposed project. Response: This project proposes for new pipe systems that they shall be designed to sufficient capacity to convey and contain at a minimum the 25-year peak flow assuming developed conditions for on-site conditions for tributary areas and existing conditions for any off-site tributary areas all in accordance with the 1998 King County, Washington Surface Water Design Manual. Core Requirement No.5-Temporary Erosion and Sedimentation Control: All projects that require engineered drainage plans shall provide temporary erosion and sedimentation control measures that minimize the transport of sediment to drainage facilities, water resources and adjacent properties. Response: This project proposes to prevent the transport of sediment to streams, wetlands, lakes, and adjacent properties using the methods described in the 1998 King County, Washington Surface Water Design Manual, including establishing clearing limits, cover measures, and providing perimeter protection in the form of silt fences. In addition,traffic area stabilization will be constructed in the form of rock construction entrances, and a temporary sediment retention pond will be constructed at the proposed detention pond location prior to discharge of runoff from the site during construction. Core Requirement No. 6 - Maintenance and Operations: Maintenance of all drainage facilities constructed or modified by a proposed project is the responsibility of the property owner,except the City of Renton may assume maintenance of drainage_facilities constructed for formal plat subdivisions, planned unit developments, and some short plat subdivisions two years after construction approval. 7729.007 [JPJ/bq/athl Response: All drainage facilities,including catch basins and conveyance systems,detention and water • quality facilities will be located in the right-of-way of street improvements or in the tract or easement designated for that purpose, and will be maintained by the City of Renton in perpetuity. Core Requirement No.7-Bonds and Liability: All drainage facilities for the proposed projects must be constructed in conformance with the bond and liability requirements of the City of Renton. Response: This project concurs with all bonds and liability requirements as dictated by the City of Renton. 7729.007 [JPJ/bq/ath] 3.0 ANALYSIS OF TWELVE SPECIAL REQUIREMENTS Special Requirement No. 1-Critical Drainage Areas: If a proposed project lies within a designated critical drainage area as indicated on critical drainage area maps, then the proposed project drainage review and engineering plans shall be prepared in accordance with the special critical drainage area requirements that have been formally adopted by public rule. Response: The proposed project site does not Iie within a critical drainage area. Special Requirement No. 2- Compliance with an Existing Master Drainage Plan: If a proposed project lies within an area covered by an approved master drainage plan as listed at the City of Renton Division Permit center, then the proposed projects drainage review and engineering plan shall be prepared in accordance with any special requirements of the master drainage plan. Response: The project site does not lie with an existing master drainage plan. Special Requirement No.3-Conditions Requiring a Master Drainage Plan: If a proposed project is a master plan development as described in an adopted community plan or is a subdivision or planned unit development that will eventually have more than 100 single family residential lots or is a commercial development or planned unit development that will eventually construct more than 50 acres of impervious surface or will clear an area of more than 500 acres within a contiguous drainage area subbasin, then a master drainage plan must be prepared. Response: This site does not meet any of the conditions requiring a master drainage plan. Special Requirement No.4-Adopted Basin and Community Plans: If a proposed project lies within an area with an adopted basin or community plan as listed at the City of Renton Permit Center, then the proposed project drainage review and engineering plan shall be prepared in conformance with the special requirements of the adopted basin plan or community plan. Response: This project site does not he within an adopted basin or community plan area. Special Requirement No.5-Special Water Quality Controls:If any threshold area of the proposed project contains more than one acre of new impervious surface that will be subject to vehicular use or storage of chemicals and proposes direct discharge of runoff to regional facilities, receiving water,lake, wetland or closed depression without on-site peak rate runoff control or proposes discharge of runoff through overland flow or on-site infiltration into a Class I or 2 stream or a Class 1 wetland within a one mile radius downstream from the project site, then the threshold discharge area shall have a wet pond meeting the standards of the City of Renton employed to treat a projects runoff prior to discharge from the site. Response: This project proposes a wet pond as a methodology of stormwater water quality treatment. Therefore it meets this requirement without necessarily having to. Special Requirement No. 6 - Coalescing Plate Oil/Water Separator: If a proposed project will construct more than five acres of impervious surface in any threshold discharge area, that will be subject to petroleum storage or transfer, or high vehicular use,or heavy equipment use storage or maintenance, • 7729.007 [JPJ/bgl then a coalescing plate or equivalent oil/water separator shall be employed in the threshold discharge area to treat the project's runoff prior to treatment by a wet pond, wet vault or water quality Swale. Response: This project does not meet the threshold of this requirement,therefore,no coalescing plate oil/water separator is required. Special Requirement No. 7 - Closed Depression: If a proposed project will discharge runoff to an existing closed depression that has greater than 5,000 square feet of water surface area at overflow elevation, then the project must meet the requirement of closed depression. Response: This project does not discharge to a closed depression in any of its downstream drainage course. Special Requirement No.8-Use of Lakes,Wetlands or Closed Depressions for Peak Rate Runoff Control: If a project proposes to use a lake, wetland or closed depression for peak rate runoff control consistent with Core Requirement No. 3 or use a lake, wetland or closed depression to receive a direct discharge consistent with an exemption from Core Requirement No. 3 or increase the volume of runoff to an off-site closed depression, then the project must meet all the requirements of the sensitive areas ordinance and rules for such use and include water quality controls consistent with Special Requirement No.5 and observe limits on any increases to the floodplain as described in the 1990 King County Surface Water Design Manual. Response: This project does not plan the use of a lake,wetland or closed depression for peak rate runoff control. -' Special Requirement No.9-Delineation of 100-year Flood Plain: If a proposed project contains or abuts a stream, lake, wetland or closed depression, or if other King County regulations require study of flood hazards, then the 100-year floodplain boundaries based on an approved flood hazard study as described in the 1990 King County Surface Water Design Manual shall be delineated on the site improvement plans and profiles and on any final subdivision maps prepared for the proposed development. Response: This project does not contain or abut a stream, lake, wetland or closed depression. Special Requirement No. 10-Flood Protection Facilities for Type 1 and 2 Streams: If a proposed project contains or abuts a Class Z or 2 stream that has an existing flood protection facilities such as a levee, revetment or berm or proposes to construct or modify an existing flood protection facility, then the flood protection shall be analyzed and/or designed as described in the 1990 King County Surface Water Design Manual to demonstrate conformance with the Federal Emergency Management Administration Regulations. Response: This project does not contain or abut a Class I or II stream and is not proposing to modify an existing flood protection facility. Therefore, no flow protection facility needs to be analyzed and/or designed as described in the 1998 King County, Washington Surface Water Design Manual for this special requirement. Special Requirement No. 11 - Technical Analysis and Report: If a project proposes to construct a pond or an infiltration system within 200 feet from the top of the steep slope or on a slope with a gradient 7729.007 [JPJ/bq/athl steeper than I5 percent or using a berm higher than 6 feet or modify existing flow protection facilities, • then a geotechnical analysis and report shall be prepared and stamped by a geotechnical professional and civil engineer that shall address at minimum the analysis described in the 1990 King County Surface Water Design Manual. Response: This project does not meet any of the threshold requirements for this Special Requirement No. 11. Special Requirement No.12-Soils Analysis and Report: If the soils underlying a proposed project have not been mapped or if the existing soil maps are in error of not a sufficient resolution to allow the proper engineering analysis of the proposed site to be performed, than a soils analysis and report shall be prepared and stamped by a professional civil engineer with expertise in soils to verify and/or map the underlying soils by addressing the minimum as described in the 1990 King County Surface Water Design Manual. Response: A geotechnical engineering study has been prepared for this project site and is dated December 26,2000,prepared by Earth Consultants Incorporated and is included, • • 7729.007 [JPJ/bg] EXHIBIT "D" FEMA MAP LEGEND • CIAL SPE FLOOD Euz�RD ARus Nl/HDATFD Fr CIAL FO C. ZONE AE Et Esd a..a4w sa..:.a ZONE W laa!Ayh a•m)law esJl/iw ANa.Ywy�� Ime Aad dnr• ZONE AO Aeptls d m I Pal OrE,M1 4m�ra1 Im As a awW�4 watae+b•awe•+.d. zONE AFE Taa�.v�Ewe y,•+mhs A.d NATIONAL FLOOD INSURANCE PROGRAM ZONE. �I�•,.,��,,,,_,�„� ZONE VT Cau -w� en .wa NOODWAV--USIry 20NE AE OTzoNHEREz FLOOD�AA_ FIRM k..�A••mnle Awa FLOOD INSURANCE RATE MAP C� OT ma r KING COUNTY, WASHINGTON AND UNDEVELOPED COASTAL,+BRIERS INCORPORATED AREAS �ml PANEL 982 OF 1725 ----- RwA Euwawl (SEE MAP INDEX FOR PANELS NOT PRINTED) �_��,_ Rew..o,E•v�A.r �z� sP.ow R•,e �o A,om CONFARIS' cent cw. R••a Elnwwn COMMUNITY NUMBER PANEL SUFFIX iw... A0•'" E"o° '�"'° 513------• KM COMM. 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' � o, k\ - ac, - :N,"t� 4�"��JS€`aH.!t ��`� � �i�, KIMEM Ilk, \_ \L �� UN�q, r_ ! ga Vl- gme"A HERS zs�1 O-SAS __\ isffsr Gxi " k 1 ' �� �,.g� \. C �~ jg� r'11\ i � r Ali. MR pop �.. � � r fil 'fir ���=, _ �.. �� \�a� z �3• l� GEOTECHNICAL ENGINEERING STUDY PROPOSED PARKSIDE COURT SOUTHEAST 136 " STREET AND 146 .. AVENUE SOUTHEAST RENTON, WASHINGTON E-9534 December 26, 2000 PREPARED FOR HARBOUR HOMES • Kristina M. Weller, P.E. Project Engineer Kyle R. CampbeftAJ '`� `� => Manager of Geotechnica W is ,3 EJ. Earth Consultants, Inc. 1805 - 136th Place Northeast, Suite 201 Bellevue, Washington 98005 (425) 643-3780 . Toll Free 1-888-739-6670 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNiCAL ENGINEERING REPORT More construction problems are caused by site subsur- technical engineers who then render an opinion about face conditions than any other factor. As troublesome as overall subsurface conditions,-their likely reaction to subsurface problems can be, their frequency and extent proposed construction activity,and appropriate founda- have been lessened considerably in recent years,due in tion design. Even under optimal circumstances actual large measure to programs and publications of ASFE/ conditions may differ from those inferred to exist. The Association of Engineering Firms Practicing in because no geotechnical engineer,no matter how the Geosciences. qualified, and no subsurface exploration program, no The following suggestions and observations are offered matter how comprehensive,can reveal what is hidden by to help you reduce the geotechnical-related delays, earth, rock and time.The actual interface between mate- cost-overruns and other costly headaches that can rials may be far more gradual or abrupt than a report indicates. Actual conditions in areas not sampled may occur during a construction project. differ from predictions. Nothing can be done to prevent the unanticipated, but steps can be taken to help minimize their A GEOTECHNICAL ENGINEERING impact. For this reason, most experienced owners retain their REPORT IS BASED ON A UNIQUE SET geotechnical consultants through the construction stage,to iden- tify variances,conduct additional tests which may be OF PROJECT-SPECIFIC FACTORS needed,and to recommend solutions to problems encountered on site. A geotechnical engineering report is based on a subsur- face exploration plan designed to incorporate a unique SUBSURFACE CONDITIONS set of project-specific factors.These typically include: the general nature of the structure involved, its size and CAN CHANGE configuration; the location of the structure on the site and its orientation; physical concomitants such as Subsurface conditions may be modified by constantly- access roads, parking lots. and underground utilities, changing natural forces. Because a geotechnical engi- and the level of additional risk which the client assumed neering report is based on conditions which existed at by-virtue of limitations imposed upon the exploratory the time of subsurface exploration,construction decisions program. To help avoid costly problems.consult the should not be based on a geotechnical engineering report whose geotechnical engineer to determine how any factors adequacy may have been affected by time- Speak with the geo- which change subsequent to the date of the report may technical consultant to learn if additional tests are advisable before construction starts. affect its recommendations. Unless your consulting geotechnical engineer indicates Construction operations at or adjacent to the site and otherwise, your geotechnical engineering report should not natural events such as floods, earthquakes or ground- be used: water fluctuations may also affect subsurface conditions -When the nature of the proposed structure is and, thus, the continuing adequacy of a geotechnical changed, for example. if an office building will be report. The geotechnical engineer should be kept erected instead of a parking garage.or if a refriger- apprised of any such events, and should be consulted to ated warehouse will be built instead of an unre- determine if additional tests are necessary. frigerated one; -when the size or configuration of the proposed GEOTECHNICAL SERVICES ARE structure is altered; PERFORMED FOR SPECIFIC PURPOSES When the location or orientation of the proposed AND PERSONS structure is modified; When there is a change of ownership, or Geotechnical engineers' reports are prepared to meet -for application to an adjacent site. the specific needs of specific individuals. A report pre- Geotechnical engineers cannot accept responsibility for problems pared for a consulting civil engineer may not be ade- which may develop if they are not consulted after factors consid- quate for a construction contractor,or even some other ered in their report's development have changed. consulting civil engineer. Unless indicated otherwise, this report was prepared expressly for the client involved and expressly for purposes indicated by the client. Use MOST GEOTECHNICAL "FINDINGS" by any other persons for any purpose,or by the client ARE PROFESSIONAL ESTIMATES for a different purpose, may result in problems. No indi- vidual other than the client should apply this report for its Site exploration identifies actual subsurface conditions intended purpose without first conferring with the geotechnical only at those points where samples are taken,when engineer. No person should apply this report for any purpose they are taken. Data derived through sampling and sub- other than that originally contemplated without first conferring sequent laboratory testing are extrapolated by geo- with the geotechnical engineer. I ( ; Earth Consultants Inc. G(,oiechnkal Engineers.Geologists&Environmenml k-in vitiLS December 26, 2000 E-9534 Harbour Homes 1010 South 336th Street, Suite 305 Federal Way, Washington 98003-6385 Attention: Mr. Kurt Wilson Dear Mr. Wilson: We are pleased to submit our report titled "Geotechnical Engineering Study, Proposed Parkside Court, Southeast 136t' Street and 146' Avenue Southeast, Renton, Washington." This report presents the results of our field exploration, selective laboratory tests, and engineering analyses. The purpose and scope of our study was outlined in our December 15, 2000 proposal. Based on the results of our study, it is our opinion the project can be constructed generally as planned. Building support may be provided using conventional spread and continuous foundation systems bearing on competent native soils or on structural fill used to modify site grades. Slab-on-grade floors may be similarly supported. We appreciate this opportunity to be of service to you. If you have any questions or if we can be of further assistance, please call. Respectfully submitted, EARTH CONSULTANTS, INC. Kyle R. Campbell, P.E. Manager of Geotechnical Services KMW/KRCf)rrp 1805-136th Place N.E.,Suite 201.Bellevue,Washington 98005 Bellevue(425)643-3780 FAX(425)746-0860 Toll Free(888)739-6670 • TABLE OF CONTENTS E-9534 PAGE INTRODUCTION .................................................................................................. 1 General ........................................................................................................... 1 ProjectDescription ........................................................................................... 1 SITECONDITIONS ................................................................................................ 2 Surface........................................................................................................... 2 Subsurface ..................................................................................................... 2 Groundwater .................................................................................................. 3 LaboratoryTesting .......................................................................................... 3 DISCUSSION AND RECOMMENDATIONS................................................................ 3 General........................................................................................................... 3 Site Preparation and General Earthwork .............................................................. 4 Foundations.................................._.................................................................... 5 Retaining and Foundation Walls ........................................................................ 6 • Slab-on-Grade Floors ................................................ . .................................... 7 Seismic Design Considerations........................................................................... 7 Excavationsand Slopes .................................................................................... 8 SiteDrainage..........I......................................................................................... 9 Utility Support and Backfill ................................................................................. 10 PavementAreas............................................................................................... 10 LIMITATIONS ....................................................................................................... 11 AdditionalServices............................................................._............................. 11 APPENDICES Appendix A Field Exploration Appendix B Laboratory Test Results ILLUSTRATIONS Plate 1 Vicinity Map Plate 2 .Test Pit Location Plan Plate 3 Typical Footing Subdrain Detail Plate 4 Utility Trench Backfill Plate Al Legend Plates A2 through A7 Test Pit Logs • Plate 131 through B2 Grain Size Analyses Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY PROPOSED PARKSIDE COURT SOUTHEAST 136T" STREET AND 146T" AVENUE SOUTHEAST RENTON, WASHINGTON E-9534 INTRODUCTION General This report presents the results of the geotechnical engineering study completed by Earth Consultants, Inc. (ECI) for the proposed Parkside Court in Renton, Washington. The general location of the site is shown on the Vicinity Map, Plate 1 . The purpose of this study was to explore the subsurface conditions at the site and based on the conditions encountered to develop geotechnical recommendations for the proposed site development. Project Description We understand it is planned to develop the site with twenty-one (21) single family residence lots with access roadway and drainage facilities. - At the time our study was performed, the site, proposed lot locations, and our exploratory locations were approximately as shown on the Test Pit Location Plan, Plate 2. The proposed development will include asphalt-surfaced parking and driveway areas. We anticipate traffic will consist of passenger vehicles and occasional service and delivery trucks. If the above design criteria are incorrect or change, we should be consulted to review the recommendations contained in this report. In any case, ECI should be retained to perform a general review of the final design. Earth Consultants, Inc. • GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 2 SITE CONDITIONS Surface The subject site is located on the northeast corner of Southeast 136' Street and 1461h Avenue Southeast (see Plate 1, Vicinity Map). The site is approximately rectangular in shape, extending about 630 feet in the east-west direction and 343 feet in the north- south direction. The site is bordered on the west by Maplewood Heights School, on the south by a park, on the north by undeveloped property and on the east by the proposed Maplewood Estates. The site topography is gently rolling with about six to ten feet of elevation change between the low and high areas. The western portion of the site is currently occupied by a mobile home and four car garage with an apartment above. Landscaped areas surround the residence. The remaining site area is vegetated in large trees and underbrush. Subsurface Subsurface conditions were evaluated by excavating six test pits at the approximate locations shown on Plate 2. Please refer to the Test Pit Logs, Plates A2 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. Our test pits indicate the site is immediately underlain by a two to ten inch thick layer of topsoil and rootmass. This soil unit is characterized by its brown to black color and the presence of organic material. This soil layer is not considered suitable for use in support of foundations, slabs-on-grade, or pavements. In addition, it is not suitable for use as a structural fill, nor should it be mixed with material to be used as structural fill. Underlying the topsoil in test pit TP-1 and TP-2, we encountered about one foot of fill. The fill consisted of silty sand (Unified Classification SM). This soil unit may be suitable for use as structural fill. The native soil consists of dense to very dense poorly graded sand with silt and gravel (SP-SM). This soil unit is suitable for support of building loads. s Earth Consultants, Inc. • GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 3 Groundwater Groundwater seepage was not encountered in our test pits. The contractor should be made aware that groundwater is not static. There will be fluctuations in the level depending on the season, amount of rainfall, surface water runoff, and other factors. Generally, the water level is higher and seepage rate is greater in the wetter winter months (typically October through May). Laboratory Testing Laboratory tests were conducted on several representative soil samples. to verify or modify the field soil classification and to evaluate the general physical properties and engineering characteristics of the soil encountered. Visual field classifications were supplemented by grain size analyses on representative soil samples. Moisture content tests were performed on all samples. The results of laboratory tests performed on specific samples are provided either at the appropriate sample depth on the individual • boring logs or on a separate data sheet contained in Appendix B. It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and their use in guiding our engineering judgement. ECI cannot be responsible for the interpretation of these data by others. In accordance with our Standard Fee Schedule and General Conditions, the soil samples for this project will be discarded after a period of fifteen days following completion of this report unless we are otherwise directed in writing. DISCUSSION AND RECOMMENDATIONS General Based on the results of our study, it is our opinion the proposed development can be constructed generally as planned. Building support may be provided using conventional spread and continuous foundation systems bearing on competent native soils or on structural fill used to modify site grades. Slab-on-grade floors may be similarly supported. • Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 4 This report has been prepared for specific application to this project only and in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area for the exclusive use of Harbour Homes and their representatives. No warranty, expressed or implied, is made. This report, in its entirety, should be included in the project contract documents for the information of the contractor. Site Preparation and General Earthwork Based on the preliminary site plan, it appears site grading will consist of grading the lots, installing underground utilities and grading the street. The building and pavement areas should be stripped and cleared of foundations, surface vegetation, organic matter and other deleterious material. Existing utility pipes to be abandoned should be plugged or removed so that they do not provide a conduit for water and cause soil saturation and stability problems. We understand the existing residence on the site has a septic system. The septic system should be removed and replaced with • structural fill. Based on the thickness of the topsoil layer, encountered at our test pit locations, we estimate a stripping depth of six inches in the landscaped areas of the site and twelve inches or more in the forested-areas of the site. Stripped materials should not be mixed with materials to be used as structural fill. Following the stripping, the ground surface where structural fill, foundations, or slabs are to be placed should be observed by a representative of ECI. Proofrolling may be necessary in order to identify soft or unstable areas. Proofrolling should be performed under the observation of a representative of ECI. Soil in loose or soft areas, if recompacted and still yielding, should be overexcavated and replaced with structural fill to a depth that will provide a stable base beneath the general structural fill. The optional use of a geotextile fabric placed directly on the overexcavated surface may help to bridge unstable areas. • Earth Consultants, inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 5 Structural fill is defined as compacted fill placed under buildings, roadways, slabs, pavements, or other load-bearing areas. Structural fill under floor slabs and footings should be placed in horizontal lifts not exceeding twelve (12) inches in loose thickness and compacted to a minimum of 90 percent of its laboratory maximum dry density determined in accordance with ASTM Test Designation D-1557-91 (Modified Proctor). The fill materials should be placed at or near their optimum moisture content. Fill under pavements and walks should also be placed in horizontal lifts and compacted to 90 percent of maximum density except for the top twelve (12) inches which should be compacted to 95 percent of maximum density. During dry weather, most soils which are compactible and non-organic can be used as structural fill. Based on the results of our laboratory tests, the site soil at the time of our exploration appears to near the optimum moisture content and should be suitable for use in its present condition as structural fill, provided the grading operations are conducted during dry weather. Based on laboratory testing, the native soil has between 3 and 14 percent fines passing the No,200 sieve. Soil with fines in this range will degrade if exposed to excessive moisture, and compaction and grading will be difficult if the soil moisture increases significantly above its optimum condition. If the native soil is exposed to moisture and cannot be compacted then it may be necessary to import a soil which can be compacted. During dry weather, most non- organic compactible soil with a maximum particle size of six inches can be used. Fill for use during wet weather should consist of a fairly well graded granular material having a maximum particle size of six inches and no more than 5 percent fines passing the No. 200 sieve based on the minus 3/4-inch fraction. A contingency in the earthwork budget should be included for this possibility. Foundations Based on the results of our study, it is our opinion the proposed building may be supported on a conventional spread and continuous footing foundation bearing on competent native soil or on structural fill used to modify site grades. For frost protection considerations, exterior foundation elements should be placed at a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum depth of twelve (12) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. • Earth Consultants,Inc. • GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 6 With foundation support obtained as described, for design, an allowable bearing capacity of two thousand five hundred (2,500) pounds per square foot (psf) for structural fill or competent native soil can be used. Continuous and individual spread footings should have minimum widths of eighteen (18) and twenty-four (24) inches, respectively. Loading of this magnitude would be provided with a theoretical factor-of-safety in excess of three against actual shear failure. For short-term dynamic loading conditions, a one- third increase in the above allowable bearing capacities can be used. With structural loading as expected, total settlement in the range of one inch is anticipated with differential movement of about one-half inch. Most of the anticipated settlements should occur during construction as dead loads are applied. Horizontal loads can be resisted by friction between the base of the foundation and the supporting soil and by passive soil pressure acting on the face of the buried portion of the foundation. For the latter, the foundation must be poured "neat" against the competent native soils or backfilled with-.structural fill. For frictional capacity, a coefficient of .40 can be used. For passive earth pressure, the available resistance can be computed using an equivalent fluid pressure of three hundred fifty (350) pounds per square foot (pcf). These lateral resistance values are allowable values, a factor-of-safety of 1 .5 has been included. As movement of the foundation element is required to mobilize full passive resistance, the passive resistance should be neglected if such movement is not acceptable. Footing excavations should be observed by a representative of ECI, prior to placing forms or rebar, to verify that conditions are as anticipated in this report. Retaining and Foundation Walls Retaining walls and foundation walls that act as retaining walls should be designed to resist lateral earth pressures imposed by the retained soils. Walls that are designed to yield can be designed to resist the lateral earth pressures imposed by an equivalent fluid with a unit weight of thirty five (35) pcf. If 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 backfill 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 Foundations section is applicable to retaining walls. • Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 7 If design against earthquake loading is desired, a rectangular pressure distribution equal to six times the wall height (6H) should be added to the above lateral earth pressure values. In order to reduce the potential for hydrostatic forces building up behind the walls, retaining walls should be backfilled with a suitable free-draining material extending at least eighteen (18) inches behind the walla 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. Slab-on-Grade Floors Slab-on-grade floors may be supported on competent native soil subgrade or on structural fill. Disturbed subgrade soil must either be recompacted or replaced with structural fill. Concrete slabs resting on soil-ultimately cause the moisture content of the underlying soils to rise. This results from continued capillary rise and the ending of normal evapotranspiration. As concrete is permeable, moisture will eventually penetrate the slab resulting in a condition commonly known as a "wet slab" and poor adhesion of floor coverings. Therefore if slab moisture is a concern, the slab should be provided with a minimum of four inches of free-draining sand or gravel. In areas where slab moisture is undesirable, a vapor barrier such as a 6-mil plastic membrane may be placed beneath the slab. Two inches of damp sand may be placed over the membrane for protection during construction and to aid in curing of the concrete. Seismic Design Considerations The Puget Lowland is classified as a Seismic Zone 3 in the 1997 Uniform Building Code (UBC). Earthquakes occur in the Puget Lowland with regularity, however, the majority of these events are of such low magnitude they are not detected without instruments. Large earthquakes do occur, as indicated by the 1949, 7.1 magnitude earthquake in the Olympia area and the 1965, 6.5 magnitude earthquake in the Midway area. • Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 8 There are three potential geologic hazards associated with a strong motion seismic event at this site: ground rupture, liquefaction, and ground motion response. Ground Rupture: The strongest earthquakes in the Puget Lowland are widespread, subcrustai events, ranging in depth from thirty (30) to fifty-five (55) miles. Surface faulting from these deep events has not been documented to date. Therefore, it is our opinion, that the risk of ground rupture during a strong motion seismic event is negligible. Liquefaction: Liquefaction is a phenomenon in which soils lose all shear strength for short periods of time during an earthquake. Groundshaking of sufficient duration results in the loss of grain to grain contact and rapid increase in pore water pressure, causing the soil to behave as.a fluid. To have a potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sands and silt); it must be loose to medium dense; it must be below the groundwater table; and it must be subject to sufficient magnitude and duration of groundshaking. The effects of liquefaction may be large total and/or differentiif settlement for structures founded in the liquefying soils. Based on the density of the site soils, it is our opinion the potential for liquefaction over the site during a seismic event is negligible. Ground Motion Response: In accordance with Table 16-J of the 1997 UBC, soil type SC should be used in design. - Excavations and Slopes The following information is provided solely as a service to our client. Under no circumstances should this information be interpreted to mean that ECI is assuming responsibility for construction site safety or the contractor's activities; such responsibility is not being implied and should not be inferred. 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 site soils 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 (Horizontal:Vertical). If slopes of this inclination, or flatter, cannot be constructed, temporary shoring may be necessary. • Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 9 Shoring will help protect against slope or excavation collapse, and will provide protection to workers in the excavation. If temporary shoring is required, we will be available to provide shoring design criteria. Permanent cut and fill slopes should be inclined no steeper than 2H:1 V. Cut slopes should be observed by ECI during excavation to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains. In any case, water should not be allowed to flow uncontrolled over the top of slopes. Permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. Site Drainage Groundwater seepage was not-encountered in our test pits. If seepage is encountered in foundation or grade beam excavations during construction, the bottom of the excavation should be sloped to one or more shallow sump pits. The collected water can then be pumped from these pits to a positive and permanent discharge, such as a nearby storm drain. Depending on the magnitude of such seepage, it may also be necessary to interconnect the sump pits by a system of connector trenches. The appropriate locations of subsurface drains, if needed, should be established during grading operations by ECI's representative at which time the seepage areas, if present, may be more clearly defined. During construction, the site must be graded such that surface water is directed off the site. Water must not be allowed to stand in areas where buildings, slabs or pavements are to be constructed. Loose surfaces should be sealed at night by compacting the surface to reduce the potential for moisture infiltration into the soils. Final site grades must allow for drainage away from the building foundations. The ground should be sloped at a gradient of 3 percent for a distance of at least ten feet away from the build- ings, except in paved areas, which can be sloped at a gradient of 2 percent. • Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 10 Footing drains should be installed around the building perimeters, at or just below the invert of the footing, with a gradient sufficient to initiate flow. A typical detail is provided on Plate 3. Under no circumstances should roof downspout drain lines be connected to the footing drain system. Roof downspouts must be separately tightlined to discharge. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. Utility Support and Backfill Based on the soil conditions encountered, the soils expected .to be exposed by utility excavations should provide adequate support for utilities. Utility trench backfill is a primary concern in reducing the potential for settlement along utility alignments, particularly_in pavement areas. It is important that each section of utility line be adequately supported in the bedding material. The material should be hand tamped to ensure support is provided around the pipe haunches. Fill should be carefully placed and hand tamped to about twelve inches above the crown of the pipe before heavy compaction equipment is brought into use. The remainder of the trench backfill should be placed in lifts having a loose thickness of less than twelve inches. A typical trench backfill section and compaction requirements for load supporting and non-load supporting areas is presented on Plate 4. Pavement Areas The adequacy of site pavements is related in part to the condition of the underlying subgrade. To provide a properly prepared subgrade for pavements, the subgrade should be treated and prepared as described in the Site Preparation section of this report. This means at least the top twelve (12) inches of the subgrade should be compacted to 95 percent of the maximum dry density (per ASTM D-1557-91). It is possible that some localized areas of soft, wet or unstable subgrade may still exist after this process. Therefore, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. Earth Consultants, Inc. • GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 11 The following pavement section can be used for lightly-loaded areas (car traffic): • Two inches of asphalt concrete (AC) over four inches of crushed rock base (CRB) material, or • Two inches of AC over three inches of asphalt treated base (ATB) material. Heavier truck-traffic areas will require thicker sections depending upon site usage, pavement life and site traffic. We will be pleased to assist in developing appropriate pavement sections for heavy traffic zones, if needed. Pavement materials should conform to WSDOT specifications. The use of a Class_ B asphalt mix is suggested. LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective • laboratory testing and engineering analyses, the design information provided us, and our experience and engineering judgement. The conclusions -and recommendations are professional opinions derived in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No warranty is expressed or implied. The recommendations submitted in this report are based upon the data obtained from the test pits. Soil and groundwater conditions between test pits may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, ECI should be requested to reevaluate the recommendations of this report and to modify or verify them in writing prior to proceeding with the construction. Additional Services As the geotechnical engineer of record, ECI should be retained to perform a general review of the final design and specifications to verify that the earthwork and foundation recommendations have been properly interpreted and implemented in the design and in the construction specifications. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Harbour Homes E-9534 December 26, 2000 Page 12 ECI should also be retained to.provide geotechnical services during construction. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. We do not accept responsibility for the performance of the foundation or earthwork unless we are retained to review the construction drawings and specifications, and to provide construction observation and testing services. • Earth Consultants, Inc. ell UCk% "4 CC�J w � Z v Ilk x§. i cU O N R :ode R �i'u 4' ,a ` `" `� �'�" ''p.r _ ^� `� �9 ,`4 .. •"�1r O G > o ^Q� k £ , raua5 � ,i .I i_G •..,.i +.a3x s a� ,r. a � +, .•` _„ ..® V p r CL ,. CO :Jq�K R i >�S '� -fit_, �fi� �Y . `i rt h• �2: � '�aF'9'i�0. "r"';:.: , ,., ' 1'4 ��, 4 �.,. a,;.�: ,. •q �, 2 � p,,� VJ t��� :'��3i�t ,� �i, v ' .a , 4 al� � �a�}c 7k.• '�._ :.�y}��� ,.e� � ��:.. �r ,N C d > na {���°�'a` } � a as ` �a��.{ ; � �r �� y�- ��,� '��•+S �� ;� i�".�. F `�"�, � G J"1O' to e ksi + Ot. "' r�'+ K'�,r� 7 3 Sr.£.� � ? �1 j ` ::.� ✓ �j> *:°f � � i I�.: '° � O I^ A`,I U c i3 Q � N � Q p N T e }} R co 11�' '5... °jY`s', - '�.� � ^x ` IDS tNz .�i •ls e '� 'L e G Va O Cll C C CD RS JA4--� .. 4a, . . q� C .yi+ Ct�tl F" !A CCfL `1 [np ZW 2 1 PEI pMy.i Yet,, is '} oA., f`4 y ..} 1 ci. �. \} 40D `P .,i Rn }E i•- "� � F'' LdiU ? t: �.� �£ � r �'. �t e �`3s. #y .t 1. (LJ 1 1 S K, s 2 F, LI } F f + F t 7 Y s- r s f _ t Ir o 400 i i i i f LEGEND j TP-1-11— Approximate Location of ECI Test Pit, Proj. No. E-9534, Dec. 2000 Approximate Scale 0 5o 100 2001t. - Subject Site E Existing Building ---- Earth Consultants, Inc. �� Lot Number Geotechnical Engineers.Geo"Vsts S Environmental Scnmism -� ; Test Pit Location Plan Parkside Court King County, Washington • NOTE:This plate may contain areas of color. ECI cannot be responsible for any subsequent Drwn. CLS Date Dec. 2000 Proj. No. 9534 misinterpretation of the information resulting from black&white reproductions of this plate. Checked KMW Date 12/28/00 Plate 2 4 Non-Load Supporting Floor Slab or Areas Roadway Areas s Varies 0 0 0 0 �y � 1F0ot Minim um u M' i Bac kfill _- 80 Varies A 1 g �07 - .o` PIPE 6 r. o $ C�'#n C•2-o�:V=e.• p:. °C'a � �0- oo` ico g oQo�O 0.0.. �ar. °O�O•�Ooo. 00 O Oe0• �"v.�- O oe Q•. o D 4:�.:b• °moo��}o-;o� 0004.•oO•� LEGEND: Asphalt or-Concrete Pavement or Concrete Floor Slab Base Material or Base Rock e Backfill; Compacted On-Site Soil or Imported Select Fill -`x Material as Described in the Site Preparation of the General Earthwork Section of the Attached Report Text. D5 Minimum Percentage of Maximum Laboratory Dry Density as Determined by ASTM Test Method D 1557-78 (Modified Proctor), Unless Otherwise Specified in the Attached Report Text. o •� Bedding Material; Material Type Depends on Type of Pipe and 0.0:oaop Laying Conditions. Bedding Should Conform to the Manufacturers Recommendations for the Type of Pipe Selected. t�, TYPICAL UTILITY TRENCH FILL �rtj 1 ConsWtants Inc. Parkside Court "�,� King County, Washington Proj. No. 9534 Drwn. GLS Date Dec.2000 Checked KMW Date 12/28/00 Plate 3 i 0 a _o . Slope To Drain = p min - - - <.4 z 0 inc - -s o _ - o r `.i,••,`� - ■'- :`ram'- �• . �� _ -' i$ fi�cr i Mo i. 4 inch min. Perforated Pipe _ ••• " eo a p-p O • O Wrapped in Drainage Fabric • 2 inch min. 2 inch ruin. J 4 inch max 12 inch min. SCHEMATIC ONLY-NOT TO SCALE NOT A CONSTRUCTION DRAWING LEGEND Surface seal; native sod or other low permeability material. :.j Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the :VSDOT Specifications. oDrain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down;tight jointed;with a positive gradient.Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Mirafi 140 Fitter Fabric or equivalent �I��] ConsultantsInc. TYPICAL FOOTING SUBDRA(N DETAIL Parkside Court Gcowc r"Engkx ,s c�o+ogua i E1 VWO VrcnlaJ Sc-xiu King County, Washington Proi, No. 9534 Drwn. GLS fDate Dec.2000 Checked KMW Date i2/28/00 Plate 4 APPENDIX A FIELD EXPLORATION E-9534 Our field exploration was performed on December 20, 2000. Subsurface conditions at the site were explored by excavating six test pits to a maximum depth of eight feet below the existing grade. The test pits were excavated by Northwest Excavating subcontracted to ECI, using a backhoe. Approximate test pit locations were determined by pacing from site features. The loca- tions 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 exploration 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 Al, 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 A7. 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. MAJOR DIVISIONS GRAPH LETTER TYPICAL DESCRIPTION • SYMBOL SYMBOL Gravel o � GW Well-Graded Gravels,Gravel-Sand And Clean Gravels a 8 gW Mixtures, Little Or No Fines Gravelly (little or no fines) M / GPgp Poorly-Graded Gravels,Gravel- Coarse Soils Grained Sand Mixtures, Little Or No Fines Soils More Than 50% Coarse GM Silty Gravels,Gravel-Sand- ,50% With gm Silt Mixtures Fraction Fines(appreciable XIT� Retained On amount of fines) GC Clayey Gravels. Gravel-Sand- No-4 Sieve gc Clay Mixtures Sand o o o SW Well-Graded Sands, Gravelly And Clean Sand o o' o SW Sands, Little Or No Fines Sandy (little or no fines) ,.�.:,_.:: .�..,; More Than `..:= . .... SP Poorly-Graded Sands, Gravel) 50% Material Soils 4 o#Q Sp Sands, Little Or No Fines y Larger Than More Than No.200 Sieve 50% Coarse SM Silty Sands, Sand- Silt Mixtures Size Fraction Sands With Sm Passing No.4 Fines(appreciable amount of fines) Sieve SC SC Clayey Sands, Sand-Clay Mixtures ML Inorganic Silts&Very Fine Sands,Rock Flo6r,Silty- ml Clayey Fine Sands;Clayey Silts w/Slight Plasticity Fine Silts Liquid Limit CL Inorganic Clays Of Low To Medium Plasticity, GrainSoils Clay And Less Than 50 CI Gravelly Clays, Sandy Clays, Silty Clays, Lean Clays i I { 1 { I OL Organic Silts And Organic I I I { { Ol Silty Clays Of Low Plasticity More Than MH Inorganic Silts, Micaceous Or Diatomaceous Fire mh Sand Or Silty Soils 50% Material Silts Liquid Limit Smaller TJ-an And CH Inorganic Clays Of High No.200 Sieve Greater Than Too Size Clays Ch Plasticity, Fat Clays. j OH Organic Clays Of Medium To High Oh Plasticity, Organic Silts 21, [� Pt T Pe Highly Organic Soils at, Humus, Swamp Soils +, 'tr, �11, J1+ With High Organic Contents Topsoil y 4,y y J Humus And Duff Layer Fill Highly Variable Constituents The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs. DUAL SYMBOLS are used to indicate borderline soil classification. 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 i WATER OBSERVATION WELL pcf DRY DENSITY, lbs.per cubic ft. LL LIQUID LIMIT, % a DEPTH OF ENCOUNTERED GROUNDWATER PI PLASTIC INDEX DURING EXCAVATION y SUBSEQUENT GROUNDWATER LEVEL W/DATE Earth Consultants Inc. LEGEND I ""it''wit iIWL Ignetrp.(;aALgu4S6 HI\'Ifl1tlIMT11.IW SUt-1ws Proj. No. 9534 1 Date Dec. 701 Plate Al Test Pit Log Project Name: Sheet of Parkside Court 1 1 Job No. Logged by: Date: Test Pit No,: 9534 1 KMW 12/20/00 TP-1 Excavation Contactor: Ground Surface Elevation: NW Excavating 396' Notes: � e o �, Surface Conditions: Depth of Topsoil &Sod 2" General W L _ U a -0 n a U a Notes M m a o u M ? >. C7 (n V) u) SM Brown silty SAND, loose, moist(Fill) SM Dark brown silty SAND with roots, loose, moist(Relic Topsoil) 2 S SP-SM Brown poorly graded SAND with silt,gravel and occasional cobbles, 10.3 .;:`o;; dense to very dense, moist " 4 -7%fines 5 0 6 9.5 P -11%fines 7 • $ - Test pit terminated at 8.0 feet below existing grade, No groundwater encountered during excavation. 0 a 0 0 c U W d Test Pit Log Earth Consultants Inc. Partcside Court 0 O Cccrec�tmlcalFnphxrrs.Grokr�Ls+�6FnNmrnixnrjlSclrnin.�,r� King County, Washington a F Proj. No. 9534 Dvvn. GLS Date Dec.2000 Checked KMW Date 12/28/00 Plate A2 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of Test Pit Log Project Name: Sheet of Parkside Court 1 1 Job No_ Logged by: Date: Test Pit No.: 9534 1 KMW 12/20/00 TP-2 _ Excavation Contactor: Ground Surface Elevation- NW Excavating _ 400' Notes: g o r N o Surface Conditions: Depth of Topsoil &Sod 2" General W a n S _; CL U s Notes @ E d LL E N E %) C9 rn V W SM Brown silty SAND, loose, moist (Fill) 1 SM Brown silty SAND with tree roots, loose, moist(Relic Topsoil) 2 0 s SP 10.6 -SM Brown poorly graded SAND with slit,dense, moist 4 o'¢ 5 SM Brown silty fine SAND,dense, moist s 7 Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation. S 0 O U W a a Test Pit Log I nh Consultants Inc. Parkside Court O GcmcYYmlcalFngln &FjrAmnnienral SklmtisrsKing County, Washington a F- Proj.No. 9534 Dwn_ GLS Date DeC.Z000 Checked KMW Date 12/28/00 Plate A3 Subsurface conditions depicted represent our observations at the time and location of this e)loratory hole,modified by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of Test Pit Log Project Name: Sheet of Parkside Court 1 1 Job No. Logged by: -- Date: Test Pit No.: 9534 KMW 12/20/00 TP-3 Excavation Contactor. Ground Surface Elevation: NW Excavating 408' Notes: — — 2 n L a in Surface Conditions: Depth of Topsoil &Sod 2" General wCL _ Notes M `i a o `- m D E. (9 in cn SM Dark brown silty SAND with organics, loose, moist 1 2 SM Brawn silty SAND with gravel, medium dense, moist 13.0 3 -14%fines Q 4 SP-SM Gray poorly graded SAND with silt and gravel, dense, moist e: 5 ' a o;. 4.8 6 Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation_ • 0 a 0 U W a Test Pit Log F Irtrl Consultants Inc. Parkside Court O GrarcYmicalFnglnms,Gc�kxttsN&Flrvinx"tx-nRll SCYrniibrs King County,Washington F a t- Proj.No. 9534 Dwn_ GLS Date Dec.2000 Checked KMW Date 12/28/00 Ptate A4 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of Test Pit Log Project Name: Sheet of Parkside Court • Job No. Logged by: Date: Test Pit No.: 9534 1 KMW 12/20/00 TP-4 Excavation Contactor. Ground Surface Elevation: NW Excavating _ 408' Notes: 0 0 „ Surface Conditions: Depth of Topsoil &Sod 6" General W Q t kn o a n a U a Notes M 2 E o " 0 � >. (D Un Un CO SP-SM Brown poorly graded SAND with silt, medium dense,moist o q p 2 6 o. : 3 6.8 4 SP-SM Gray poorly graded SAND with silt and gravel,very dense, moist 6 — Test pit terminated at 6.0 feet below eAsting grade. No groundwater encountered during excavation. • 0 0 0 0 U W d Test Pit Log " Earth Consultants Inc. � Parkside Court o 'n�d�Fn�n�"` h"&F"� King County,Washington LUI Proj. No, 9534 Dwn. GLS Date Dec. 2000 Checked KMW Date 12/28/00 Plate A5 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modfied by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of Test Pit Log Project Name: Sheet of Parkside Court 1 1 • Job No. Logged by. Crate: Test Pit No.: 9534 1 KMW 12/20/00 TP-5 Excavation Contactor- Ground Surface Elevation: NW Excavating _ 403' Notes: 2 -6 t T n° surface Conditions: Depth of Forest Duff 8" General W _ Notes 6 E °' "- E P �'� 0 CO V) to SP-SM Brown poorly graded SAND with silt,gravel and tree roots,loose, P moist o" t 2 2 -11%fines 3 SP-SM Brown poorly graded SAND with silt,dense, moist "I O V 5 $ 6-3 — SP-SM Brown gray poorly graded SAND with silt and gravel, dense to very dense, moist Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation. 0 0 c� U [L a Test Pit Log Earth Consultants Inc. Parkside Court O CecxcYYmRalFnglnms.C.c<krf &FleNmruimi.jlScirntt King County, Washington H a W Proj.No. 9534 Dwn. GLS Crate Dec_2000 checked KMW Crate 12/28/00 Plate A6 Subsurface conditions depicted represent our observations at the time and location of this e)loratory hole,modified by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of Test Pit Log Project Name: Sheet of Parkside Court 1 1 Job No. Logged by: gate: Tess Pit No,: 9534 KMW 12/20/00 TP-6 Excavation Contactor: Ground Surface Elevation: NW Excavating _ 400' Notes- 2 o a, Surface Conditions: Depth of Forest Duff 10" General W ,= 0. cn o a. a) ti E co Notes a co SP-SM Brown poorly graded SAND with silt and tree roots, loose, moist Q: Z,c 0 16.1 0 3 o 4 . 1 . GP Gray brown poorly graded GRAVEL with sand,dense, moist w •. • s 3.1 s l o -3%fines 6 Test pit terminated at 6.0 feet below e>dsting grade. No groundwater encountered during excavation. 0 a 0 U W a Test Pit Log Earth Consultants Inc. Parkside Court O Cc�mhal FngMrcaS,G-dc -^-&Firvlrtxmmrrji k'tc:+ih King County,Washington F a Proj. No. 9534 Dwn. GLS Date Dec. 2000 Checked KMW Date 12/28/00 Plate A7 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of APPENDIX B LABORATORY TEST RESULTS E-9534 Earth Consultants, Inc. • • • WM / - � • • •• 161imix I cmumailm I I • , .• f, .■■■.� ,..�1�■.■■■.CMS. .■. ... .■�.■..�■...�..�......■..■.�... 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W • .. • ®m• — • rtTP 5 Brownpoorly graded silty SAND with gravel • TP- • ..• , SURFACE WATER UTILITY BILLING ASSESSMENT Project Name: Parkside Court (R-2957) Note: taxlot was subdivided, new Building Permit Number: lots are being billed correctly, no new surface water charges should Billing Account Number: 510020 - suspended be billed Date to Utility Billing: 4/22/04 Business or Use: platted, residential Owner Name: Harbour Homes Bill To: same Site Address: none Description: platted "Lot Size": "Tax Lot No.": 084710-0100 Comments: delete after account is settled Tax Lot No. Area sf Impervious (sf) Assessment 0847100100 - - delete I:\BiIIingAssesments\0847100100bi11.doc\rd Print Map Page Page 1 of 1 h OWW King County . = k P!aV M I® f• IW MI I !! Parcel Map and Data 61 , ) ON71000M X11 0 VMWKV.0 w SE.2ND_cT WO 66 30_ sE�ssr tr_ 7 R- fc)=Km Ccwnty, �ZCDs a`I Co F,3 cvte LIVIed, otebLAp— e-l-cyf- �6G,903 77,77 c�t�an `ffac - http://www5.metrokc.gov/parcelviewer/Print_Process.asp 04/21/2004 Renton P,, r s���e_ ur z� (R-2 9 s ;q --- Renton City Limits �. Parcels 4 Renton Aerial •',is � H r P' g w'��4" IP # h a 3sr t .� 7'Aa,dr s WN. NfII _ ---AV rfv rF WY "A'A 'A 'A N SCALE 1 : 1,642 100 0 100 200 300 FEET http://rentonnet.org/MapGuide/maps/Parcel.mwf Wednesday, April 21, 2004 4:17 PM Map Output SW10 Z s Page 1 of 2 Pa r ' S lr& col ,-t King County ML O _ iw � M. Nap Print Page 11/2�/Zoo4 . c�i?'ccc•�s� � W LR R-4 w �' w � c►847/D— 0�00 a. a cc. Sao OXZ O 4GoG W,4 I�isf b �Cu - i,-e,cord-eJ se��srHsr —L—.J ( 1512ed2- 5 - R-4 1c)2=KING COUNTY& n M•i Legend 5e6-.:ledFealures ❑ A'3? Aq-cj-.xIu'K::Jx'3'5 c, 13 v�yrrrKuu3�, K„ 5lreels uc,: C3 Cunnn-:3�, K„ 1,o Forysl PrJdu•:�IkJn Dislrl l U N K l R3 Rcx�uu 3�, K„ Boundary RA25 Rxzj A'w U'K:J x--5w'c, El rJ -'F�cn /,e Agrk�ullural PrJdui�lbn Dislrk;l RA 5 I ray:.'c Boundary RA 10 Rra A'w u'K--J x'10 K c, El rJ.'K' Al Urban Grj-.vlh Area Line Lakes and Large Rivers R= Re,ckr.� R4u•:�kleshool Tribe R o Rc,cWr.a u 3J x•:x••c ❑ Par:�eI Imxjrporaled Area R 12 Re,ac'ca 12'J x'uc'c Zoning Labels R13 Rc.ck-r.:a 13DJx•ac•c Zoning ❑ R 24' Rc,dwr.zi 2-'J x-w- A 10 Ag c•r:ra u'K 7J x'10:K•c, ■ R Rc,�k r.� -„7J x•:x••c :Cxu'r.; ;c�•r; The information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice. King County makes no representations or warranties,express or implied,as to accuracy,completeness,timeliness,or rights to the use of such information.King County shall not be liable for any general,special,indirect,incidental,or consequential damages including,but not limited to, lost revenues or lost profits resulting from the use or misuse of the information contained on this map.Any sale of this map or information on http://www5.metrokc.gov/servlet/com.esri.esrimap.Esrimap?S erviceName=overview&Cli,... 10/24/2002 ►'King County: Assessor Property Characteristics Report Page 1 of 2 King County , ii h of ai lull® L By law this information may not be used for commercial purposes. Assessor Real Property Records: Parcel Number 0847100100 Taxpayer PARKSIDE COURT Account Number 084710010004 Tax Year 2002 Levy Code 2147 Tax Status TAXABLE Taxable Value Reason NONE OR UNKNOWN Appraised Land Value $151000 Taxable Land Value $151000 Appraised Improvement Value $27173 Taxable Improvement Value $27173 Assessor ParcelRecords: District Name RENTON Property Name Property RESIDENTIAL BLACK LOAM FIVE-ACRE Present Single Family Plat Name TRS Use (Res Use/Zone) Plat Block Water WATER System DISTRICT Plat Lot 16 Sewer PRIVATE System Lot SgFt 227819 Access PUBLIC Section/Township/Range NE 15 23 5 Street GRAVEL Surface Assessor Legal Description Records: Account Number 084710010004 Record 01 Number Legal Description 16BLACK LOAM FIVE-ACRE TRSPP ACT 37707866 MOBILE HOME This report was generated: 10/24/02 3:08:51 PM Related on-line reports: DDES: Permit Applications Report King County: Districts and Development Conditions Report 'King_County Assessor: eReal Property Report(PDF format requires Acrobat) King County Treasury Operations: Property Tax Information Recorders Office: Excise Tax Affidavits Report http://www5.metrokc.gov/webmaps/property_report.asp?PIN=0847100100 10/24/2002 - King County: Assessor Property Characteristics Report Page 2 of 2 I'Recorders Office: Scanned images of plats, surveys, and other map documents Enter a 10 digit Parcel Number: or Enter an address: Search King County I GIS Center News I Services I Comments I Search By visiting this and other King County web pages, you expressly agree to be bound by terms and conditions of the site. The details. http://www5.metroke.gov/webmaps/property_report.asp?PIN=0847100100 10/24/2002 Excise Tax Search Results Page 1 of 1 Recorder's Office r ' ° Enter Search Criteria j ReSUIts Search Results-2 matches (Records 1 -2) ETax Date Grantee Grantor Document Tax Parcel Jurisdiction Sale Sale Tax Image Number Received Type Date Amount Amount Status 1432383 6/9/95 TARANTOSA, TARANTOLA, QCD 0847100100 6/6/95 $0 $0 21 Scanned JOSEPH JOSEPH 1877161 4/1/02 GEONERCO TARANTOLA, WD 0847100100 RN 3/20/02 $475000 $8455 Scanned INC, JOSEPH &Verified Web application page format updated: September 30, 2002 Recorders Office Home Page I Customer Service Questions (Searching and indexing assistance) E-mail_the Recorders webmaster(to report website problems only) King County I News I Services I Comments I Search Links to external sites do not constitute endorsements by King County. By visiting this and other King County web pages, you expressly agree to be bound by terms and conditions of the site. The details. http://l 46.129.54.93:8193/etax/etaxResults.asp?cur=etax&scui—Results 10/24/2002 tll Nsf lYl'f OR c,) ✓ 12F:A[,F.STA'I'F,EX('ISF'TAX At F'll>,1�'1 I' 11) \ti4 Lot I ((1- .I R11 (IiAPI l R M2 45 R(N l+(H I'll R f, Irl'AN( Nhcn,t rt,v .;M hu 1a. r r3 )MUM At(In'SIl IRI\SI KI R 10,11(1 he ill I(im,No,84 IIPt1',.II for R,lu)rtmg Iransn rS of(onlrolhna Im.t I o'1 nnt\I I"n,1 1111 lit I111,U,p ulm„1 U)Rct VIUt) I IfIS\f Ft D A\�(1 WII1 N 0 1 BF A((F P I F 1)1 N 1 F SS\I 1 ARF 11,1-71RF FI'I I1(ON1PI F IFI) Name 70SEPH'`TARAIMLA AND LAURIE L. N,I„tGEONERCO INC., A WASHINGTON CORPORATIONI TARANTOLA, HUSBAND AND WIFE1 Street 14606 SE ,36TH STREET +/ SIRtI 1300 DEXTER AVENUE NORTH #500 .r --- - --- --- - J (fly/SIaIvLIP.T RENTON WA `98059 m�..(up Sal,/,p SEATTLE WA 98109 - ADDRI SS,11/} D 11 I N t PROP ION I IAX NII All 1)(11IRI%fn)y61 N(I a1: 51I I Ali PAR(I i NIA Mm R♦ </IIiSIY IRIASIIRIKPI A41 ASSI SSI 1)VAI 0 11 IAX I XI NJ 1, Nam bEONERCO INC 084710-0100-04 ( Street 1300 DEXTER AVENUE NORTH #500 (Ify/Scala/lilt "''SEATTLE WA--98109 I 1 6&I DI s(RIP HON`Of 190PIR rii Sl 1-11 1 1.,J)In p('NIN(ORPORA I I D_ KING (1)1,n t Y p OR In C11\0f Strtct Address(if proptrl) n VACANT LAND: TRACT 16 OF BLACK LOAM FIVE ACR.&TRACTS ACCORDING TO PLAT RECORDED IN VOLUME 12 OF PLATS AT PAGES 101 I14 KTNaC.OUNTY WASHINGTON. TOGETHER WITH THAT PORTION:OE VACATED STREET..ADJOINING OR ABUTTING THERETO WHICH UPON VACATION, ATTACHED TO SAID.PREMISES:'BY OPERATION OF LAW. ©Is this Prupo.rl)curnnll) \I N No a UcscrlpUu11 ol'Ptrsun d pruptrl)Included In gruss%LIIIng PALL,hofh tangible(tg fi)rnaurc ufwpnunl,etc )or mlan'ihlt c• oodwHl, C hapter d 1 dts(gnalcd as lorest land ❑ z$ agrtttncm nu, lu,,uutPtic,tit ) t- ( F g C haptcr 84 13 RC W (lassditd as urrrtnt use land(open spaec,farm ❑ and agricultural or timinr)')(haptcr 84 34 R(W I xen)pt from proptn)tat as a nonproli{ p U 11 extinption o.l mind list WA( number and explanation organization')C haptcr 84 36 R(W Ntller s 1 tempi Rtg No W AC No. (Sec Suh) _ -- Recentng SPo.ual Valuation as historic p EZ I xplanalion property)(hapter 84 26 R(W - -- -- - -- Property type `n land unl) E)land with no..building - - - — — land with presfousl)used building land w11h mobile home I yPe of DotUm,Of STATUTORY WARRANTY DEED timber only ❑building only Date of DOctliu,nt 3-20_-02 Principal Use El Apt (4)unit) ffrtsldcnDal 475,000.00 ❑trmhcr ❑agricultural ❑wnlmcrualhodustnal (Muss Stlling PIIcc $ --- -- - - —_ ❑other- _ _ Pcnonal PrOPtrts((lcducl) $ Q(1)NOIRI Of (ONIINIJAN(I (R(W8411ORR(W8434) i la ahlcStlluigPntc $ -- 11 the new owncr(s)of land that n classified(,I design Ktd as current uu. I Xti1C Los State $ or forest land wish to curnmuo.tho.ciaxrficanon ur dcsl gnat ton of such I uo.al $ - -- ---- - landthencVVuwnci(s)musi signbcluw It1htncwuwrxr(S)donotdcslrt uchnyutnllnl,It,t Slab. $_ - -- - -- to eonlimic such cl Mutation or design icon ,III conilmisaung or - additional lax t,dccdated pursuant to R(W 84 11 120 and 140 or RC W I ucal S _ 84 14 108 At dl be duc and pa)able b)the ullu or translcror at file tun Dcllinluu)t P,u Ilt) $ - - ofsale I fie toust)rise-ornomtdcicfrolotdUnlandtranslcn,l IwalDuc S 8,455.60 ---- - yuahhes 10 wnfmuc classlfi(ation or cl-Ignatrun and nnl%t w mduatt --- --- -— -- - hel(riS SlgmRurcS do not netcsS.(nl)nuan Ihe land will runaln In ( A MINIAtt)\7 of s'-no IS IWI AS A PRO(I SNIN(,I I I AND IAX lassifitahun or designation If n nu longer yuahfics it will bt rtnulVtd AI F II)AVI r - -and lilt cOmPcrt,aung I,MS still ht apphtd All ixV%oVVncn must sign I(ertd)l Indcr I'utalty of Ptpur)I lndcr Ihe 1 aw%ol 1}u State of 1 his land ❑dots O dots not yuahf)lur Loniumano.c 14ashingt io I hat the 1 orcl;( ng IS I rut And C Onut (Sec back of this lonn) Date DI Pt I ANSI NSOR Signm01lazzv (,rant (2) NO I I(1 01 (OM PI IAN(I ((hapter 84 26 R(W) RIMY- 11 - - - -- tile new owners)of property with sptual Valuation as historic property Namc _wish to continuo.this sPcclal Valuation tilt titw uwner(s)must sign Mow Dalo.agning 3- 8-02 VERETT --It tht new ooArm(s)do nnl dcslrt to c(mtiout such spi cl,d Valuation,all additional 61X talc(dacd pursuant to Chapter 84 26 R(W shall he du(, and pa)ahh h)tht seller ur tnrisleror at iho.tuns of salt Signal ue d Grantee Age" (3) OWNF-R(S)bI6NAl1JRh. &KIRBY - -- - --- --- "'- •nni) late of Signing 3-28-02 EVERETT 1'cqur: l trr"lio itstdu no n inuon for a millu lo.rrn of nu m t olt hnt(RC li f 1� lit, 1,1111n(Si 1)(9)00)Or hs h(ah lmpls ronm,m,ud -- - no. fl ,41\9400 E1877161 t)vl ti 04/01/2002 14 43 COUNTY TREASURER KING AX COUNYg8.455 00 PAGE 001 OF l�1 SALE $A5,000 00 CIIbPDF-www.fastio.com NE 1/4, NE 1/4, SEC. 15, TWP. 23 N., RGE. 5 E., W.M. MA=CH L/NEA RRE,woRAll] tdTldhRD"A• 6i n U �^ ,o•-zA• ,s #�� to wo QH9NRr wNNLEr r1tIIaA1N RA1v EOGIhO AT AA -- 5 112 rENI[Y YGM11[iVr AA�J(rwJ SAY s¢ ----- p ow uwa• arr sm Aut Avsl 3y5 99 C z A r �.Fs ;I � Ri ax Y 120 U� 19 1 = 111JJJ--- 1 I IE 'CYh399.9.- ti'pG=A99 ® t ]T v bj W 6RAIR E wx EERCE I I - - ° •e97 wARR MNpfR Y I _'————— °—G FRI 1 1 3` ,T• I I !I ° IE,-G P•wo.9) S 6mAGE [N.LRP-90.6D I 1�� I ,y ez iER i x w yr j vcvA)Aw(rwJ ¢14•UP-1- SCALE: V 9. 40, Rpw I /r.16• /r2-29S703 N� B � ��E,s•pK .J9]..9 ENCHNAIR/C �-C li'WS_J9B.9) I —a]r<Y Ap=1aV A.991E1'aI a b I ���SmEwtiS Pr/ISY-f suss A,RfA?aJL N 1Mf NI ZL IrAn ha nl�rl /INM A1E SE. I Pp9FR MR P)�QIQI�BM1LI 6tASr 5]AYAa:arG N IME IRCub wN Nr.SE.I0N rr.t 381N AK SC nrrt q Pop tt suw ae ryr�orr uc]tvsJ ly % -21IN9.6i ---- a " �6 � MATCNUNEA ;__--s`" _—g — --�-----„°°-----'a'----- V nag,.9.® y APPROVAL (w� krd wss x rt uux �Y �/O rr,.w)NEIRING A9 I `roxYR pt� eY .>lYYIrJ — /PE$I(sN rU, NING � CAa55w4X _./ rUtVEYING F ficn cq >'11•Y�-t/t'7 I - SGla:,p iEB 15200i 02/28/03 FRI 17:25 FAX 425 430 6855 RENTON-FINANCE Z 003 FEB-�9-03 08:55AM FROM-Harbour Homes ;26d8383890 T-678 P 008/OOB F-463 r ai wawo vvu ` 1 - PARKSIDE COURT ZIP CODE 980S9 RENTON PARCEL PLAN PERMITS LOT ADDRESS NUMBER NUMBER KING COUNTY ///Q 1 5500 SE znd Ct. Oni 0 3070A (MODEL) CP02338 2 5506 SE 2nd Ct. pCZ 2042D Cpo2479 3 $512 SE 2nd Ct_ ©U O 2409C CP02425 4 5518 SE 2nd Ct. �1 D 2598A CP02477 5 5524 SE 2nd Cl. 3070A CP02426� 6 5530 SE 2nd Cl. , 2598C 7 5602 SE 2nd Ct. 7 2042B 8 5608 SE 2nd Ct. 0 2409C CP02455 9 5614 SE 2nd ct. 9 2598A 10 5520 SE 2nd Ct_ 0100 3070A ill 5526 SE 2nd Cl. 0110 2598E 12 5821 SE 2nd Ct, 0 p2 fJ 2409C 13 5615 SE 2nd Ct. 0 130 2409E CP02476 14 5509 SE 2nd Ct. 0 140 2598A 15 5603 SE 2nd Ct. 01570 3070A 16 5531 SE 2nd Ct. 0160 2042D CP02478 17 5525 SE 2nd Ct. 0 170 2598E 16 5519 SE 2nd Ct. 0 00 2409C CP02492 19 5513 SE 2nd Ct. 0 190 3070A 20 5507 SE 2nd Ct. 0200 2598C CP02344 21 5501 SE 2nd Ct_ C210 2409C CP02343 ikAcl A (j 0Ili - — 2777) S VoLq, � colk, at dmc oyl't, aces S/ 0020 ZZ sw oyiCe-e-C as ac rAfl Una,Q UPDATED 2/7/2003 Page 3 Short Plat (SEPL# REQUEST FOR PROJECT# Prelim. Plat (PP# L C A.-C I -C,;I-Z-) To: Technical Services Date Cl, WO# Green# L-OA- j-CII7e-- From: Plan Review/Project Manager Project Name Lc'-e—V-�i e- (70 characters max) Description of Project: cs k'on tom- -Y\�! A Vl ay\(A V- (-I+- Q-11 C Circle Size of Waterline: 8" 10" 12" Circle One: New or Extension Circle Size of Sewerline: C8- 10" 1210 Circle One: Q!ew" or Extension Circle Size of Stomiline: 8'# 1011 1211 14" Circle One: New or Extension Address or Street Name(s) E '2- L c-ri S A V t:L Developer/Contractor/Owner: Ac-k\oc (70 characters max) Check each discipline involved in Project Ltr Drwg #of sheets per discipline Trans-Storm (Roadwayominage) (Off site unproveznentsXinclude basin name) (include TESC sheets) O Transportation (Signalization,Channelization,Lighting) Wastewater (Sanitary Sewer Maw)(include basin name) ❑ Water (Mains,Valves,Hy&m&) (Include composite&Horizontal Ctd Sheds) TS Use Only CI 'CIO, Approved by TSM Date: forms/misd92-090.130C ICD/bh