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HomeMy WebLinkAboutStudies APPLICANT 4/24/2020A STREET DRAINAGE STUDY April 2, 2020 SITE CHARACTERISTICS The subject properly is identified on County Assessor's Maps as 17-02-34-32 Tax Lot 201. It is located on the north side of A Street 250' east of 580 St. The site is vacant. EXISTING HYDROLOGY The site drains to the west then into an existing public storm drain pipe. PROPOSED HYDROLOGY The proposed drainage system for the site will consist of piping the proposed drainage to a proposed detention pond on the west side of the site. The pond was sized using the TR -55 unit hydrograph storage indication method. The proposed detention pond has an overflow outlet at elevation 511.50. The proposed outlet will drain into an existing storm drain stub to the south in A Street. The total existing flow from the site is 0.14 c.f.s. The total proposed flow from the detention pond will be reduced to 0.01 c.f.s. Attached are the following: 1. Pre -Development 10 -year flow (TR -55) 2. Post -Development 10 -year flow (TR -55) 3. Routed Post -Development 10 -year Flow (TR -55) 4. Stage -Discharge Curve 5. Stage -Storage Curve 6. Hydrograph of 10 -year Pre -development 5 -year Post -Development and 10 -year Routed Storm CONCLUSION Based on my calculations and the proposed drainage system is sized properly and will provide the necessary flow control. v���DDI%N,4�,O �e2 W EXPIRES DEC. 31, 2021 JJ/Vq.d.�_ tmpkl.txt TR -55 Tabular Hydrograph Method Input Summary Description ..................... 10 -YEAR PRE -DEVELOPMENT Rainfall Distribution ........... Type IA la/P Interpolation .............. Off Total Area ...................... 0.4000 ac Peak Time ....................... 492.0000 min Peak Flow ....................... 0.1452 ds Given Input Data: ------------------------------------------------------------------------------- Subarea D/S Subareas Area CN Tc Tt Rainfall Description (ac) (min) (min) (in) Support Data: 0.4000 69 20.0000 0.0000 4.5000 Page 1 tmpkl.txt TR -55 Tabular Hydrograph Method Input Summary Description ..................... 10 -YEAR POST -DEVELOPMENT Rainfall Distribution ........... Type IA la/P Interpolation .............. Off Total Area ...................... 0.4000 ac Peak Time ....................... 492.0000 min Peak Flow ....................... 0.3264 ds Given Input Data: ------------------------------------------------------------------------------- Subarea D/S Subareas Area CN Tc Tt Rainfall Description (ac) (min) (min) (in) Support Data: 0.4000 92 20.0000 0.0000 4.5000 Page 1 tmpkl.txt Storage Indication Method Given Input Data: File ........... Description .... 10 -YEAR ROUTED Time increment. 10.0000 min Input Files: Pre-Dev Hydrogreph curve.. C:\DRAWINGSW STREET\HD\10-yr pre.hdc Post-Dev Hydrograph curve. C:\DRAWINGSW STREET\HD\10-yr posl.hdc Stage -Storage curve....... C:\DRAWINGSW STREET\HD\pond.ssc Stage -Discharge curve..... C:IDRAWINGSW STREET\HD\pond.sdc Output Data: Routed Peak Flow ......... 0.0109 cls Routed Peak Time ......... 8.5000 min Pre -Developed Peak Flow.. 0.1452 cls Pre -Developed Peak Time.. 492.0000 min Post -Developed Peak Flow. 0.3264 ds Post -Developed Peak Time. 492.0000 min Support Calculations Time Inflow (11+12)/2 H1 Sl-(O12)T S2+(O2/2)T H2 Outflow min ds R3 ft fl3 ft3 ft ds ---------------------------------------------------------------------------------- 420.0000 0.0585 17.5600 0.0000 0.0000 17.5600 510.5376 0.0000 430.0000 0.0648 36.9961 510.5376 11.3742 48.3703 510.6035 0.0000 440.0000 0.0723 41.1235 510.6035 31.3311 72.4546 510.6551 0.0000 450.0000 0.0848 47.1269 510.6551 46.9314 94.0583 510.7013 0.0000 460.0000 0.1178 60.7847 510.7013 60.9248 121.7095 510.7605 0.0000 470.0000 0.1816 89.8263 510.7605 78.8354 168.6617 510.8610 0.0000 480.0000 0.2702 135.5273 510.8610 109.2480 244.7754 511.0239 0.0000 490.0000 0.3212 177.4012 511.0239 158.5495 335.9507 511.2191 0.0000 500.0000 0.3099 189.3331 511.2191 217.6069 406.9400 511.3711 0.0000 510.0000 0.2364 163.8935 511.3711 263.5891 427.4826 511.4150 0.0109 520.0000 0.1846 126.2971 511.4150 276.8953 403.1924 511.3630 0.0000 530.0000 0.1580 102.7712 511.3630 261.1616 363.9328 511.2790 0.0000 540.0000 0.1486 91.9650 511.2790 235.7319 327.6968 511.2014 0.0000 550.0000 0.1373 85.7740 511.2014 212.2606 298.0345 511.1379 0.0000 560.0000 0.1261 79.0201 511.1379 193.0473 272.0674 511.0824 0.0000 570.0000 0.1159 72.6039 511.0824 176.2275 248.8314 511.0326 0.0000 580.0000 0.1081 67.2008 511.0326 161.1767 228.3776 510.9888 0.0000 590.0000 0.1032 63.3737 510.9888 147.9280 211.3017 510.9523 0.0000 600.0000 0.1013 61.3475 510.9523 136.8674 198.2149 510.9243 0.0000 610.0000 0.0988 60.0343 510.9243 128.3907 188.4249 510.9033 0.0000 620.0000 0.0961 58.4584 510.9033 122.0494 180.5077 510.8864 0.0000 630.0000 0.0923 56.5072 510.8864 116.9211 173.4283 510.8712 0.0000 640.0000 0.0897 54.5937 510.8712 112.3355 166.9292 510.8573 0.0000 650.0000 0.0887 53.5243 510.8573 108.1258 161.6501 510.8460 0.0000 660.0000 0.0878 52.9615 510.8460 104.7064 157.6678 510.8375 0.0000 670.0000 0.0863 52.2298 510.8375 102.1269 154.3567 510.8304 0.0000 680.0000 0.0848 51.3293 510.8304 99.9822 151.3115 510.8239 0.0000 690.0000 0.0833 50.4288 510.8239 98.0097 148.4385 510.8177 0.0000 Page 1 tmp#l.txt 700.0000 0.0810 49.3031 510.8177 96.1487 145.4519 510.8113 0.0000 710.0000 0.0788 47.9524 510.8113 94.2142 142.1666 510.8043 0.0000 720.0000 0.0765 46.6016 510.8043 92.0862 138.6878 510.7969 0.0000 730.0000 0.0758 45.7011 510.7969 89.8329 135.5340 510.7901 0.0000 740.0000 0.0750 45.2508 510.7901 87.7900 133.0409 510.7848 0.0000 750.0000 0.0743 44.8006 510.7848 86.1752 130.9757 510.7804 0.0000 760.0000 0.0735 44.3503 510.7804 84.8375 129.1878 510.7765 0.0000 770.0000 0.0728 43.9001 510.7765 83.6794 127.5795 510.7731 0.0000 780.0000 0.0720 43.4498 510.7731 82.6376 126.0874 510.7699 0.0000 790.0000 0.0720 43.2247 510.7699 81.6712 124.8959 510.7673 0.0000 800.0000 0.0720 43.2247 510.7673 80.8994 124.1240 510.7657 0.0000 810.0000 0.0720 43.2247 510.7657 80.3994 123.6241 510.7646 0.0000 820.0000 0.0713 42.9995 510.7646 80.0756 123.0751 510.7634 0.0000 830.0000 0.0705 42.5493 510.7634 79.7200 122.2693 510.7617 0.0000 840.0000 0.0698 42.0990 510.7617 79.1981 121.2971 510.7596 0.0000 850.0000 0.0694 41.7613 510.7596 78.5683 120.3297 510.7576 0.0000 860.0000 0.0690 41.5362 510.7576 77.9417 119.4779 510.7557 0.0000 870.0000 0.0687 41.3111 510.7557 77.3900 118.7010 510.7541 0.0000 880.0000 0.0683 41.0859 510.7541 76.8868 117.9727 510.7525 0.0000 890.0000 0.0679 40.8608 510.7525 76.4150 117.2758 510.7510 0.0000 900.0000 0.0675 40.6357 510.7510 75.9636 116.5993 510.7496 0.0000 910.0000 0.0672 40.4106 510.7496 75.5254 115.9360 510.7482 0.0000 920.0000 0.0668 40.1854 510.7482 75.0957 115.2812 510.7468 0.0000 930.0000 0.0664 39.9603 510.7468 74.6716 114.6319 510.7454 0.0000 940.0000 0.0660 39.7352 510.7454 74.2511 113.9862 510.7440 0.0000 950.0000 0.0657 39.5100 510.7440 73.8328 113.3429 510.7426 0.0000 960.0000 0.0653 39.2849 510.7426 73.4161 112.7010 510.7412 0.0000 970.0000 0.0649 39.0598 510.7412 73.0004 112.0601 510.7399 0.0000 980.0000 0.0645 38.8347 510.7399 72.5852 111.4199 510.7385 0.0000 990.0000 0.0642 38.6095 510.7385 72.1705 110.7801 510.7371 0.0000 1000.0000 0.0638 38.3844 510.7371 71.7561 110.1405 510.7358 0.0000 1010.0000 0.0634 38.1593 510.7358 71.3418 109.5011 510.7344 0.0000 1020.0000 0.0630 37.9341 510.7344 70.9276 108.8618 510.7330 0.0000 1030.0000 0.0627 37.7090 510.7330 70.5135 108.2226 510.7317 0.0000 1040.0000 0.0623 37.4839 510.7317 70.0995 107.5834 510.7303 0.0000 1050.0000 0.0619 37.2588 510.7303 69.6855 106.9443 510.7289 0.0000 1060.0000 0.0615 37.0336 510.7289 69.2715 106.3051 510.7275 0.0000 1070.0000 0.0612 36.8085 510.7275 68.8575 105.6660 510.7262 0.0000 1080.0000 0.0608 36.5834 510.7262 68.4435 105.0269 510.7248 0.0000 1090.0000 0.0603 36.3301 510.7248 68.0296 104.3597 510.7234 0.0000 1100.0000 0.0598 36.0487 510.7234 67.5974 103.6461 510.7219 0.0000 1110.0000 0.0594 35.7673 510.7219 67.1351 102.9024 510.7203 0.0000 1120.0000 0.0589 35.4859 510.7203 66.6535 102.1393 510.7186 0.0000 1130.0000 0.0584 35.2045 510.7186 66.1592 101.3637 510.7170 0.0000 1140.0000 0.0580 34.9231 510.7170 65.6567 100.5798 510.7153 0.0000 1150.0000 0.0575 34.6416 510.7153 65.1490 99.7907 510.7136 0.0000 1160.0000 0.0570 34.3602 510.7136 64.6379 98.9981 510.7119 0.0000 1170.0000 0.0566 34.0788 510.7119 64.1245 98.2033 510.7102 0.0000 1180.0000 0.0561 33.7974 510.7102 63.6097 97.4071 510.7085 0.0000 1190.0000 0.0556 33.5160 510.7085 63.0940 96.6100 510.7068 0.0000 1200.0000 0.0552 33.2346 510.7068 62.5776 95.8122 510.7051 0.0000 1210.0000 0.0547 32.9532 510.7051 62.0609 95.0141 510.7034 0.0000 1220.0000 0.0542 32.6718 510.7034 61.5439 94.2157 510.7017 0.0000 1230.0000 0.0537 32.3904 510.7017 61.0267 93.4171 510.7000 0.0000 1240.0000 0.0533 32.1090 510.7000 60.5095 92.6184 510.6982 0.0000 1250.0000 0.0528 31.8275 510.6982 59.9922 91.8197 510.6965 0.0000 Page 2 tmp#l.txt 1260.0000 0.0523 31.5461 510.6965 59.4748 91.0209 510.6948 0.0000 1270.0000 0.0519 31.2647 510.6948 58.9574 90.2221 510.6931 0.0000 1280.0000 0.0514 30.9833 510.6931 58.4400 89.4233 510.6914 0.0000 1290.0000 0.0509 30.7019 510.6914 57.9226 88.6245 510.6897 0.0000 1300.0000 0.0505 30.4205 510.6897 57.4051 87.8256 510.6880 0.0000 1310.0000 0.0500 30.1391 510.6880 56.8877 87.0268 510.6863 0.0000 1320.0000 0.0495 29.8577 510.6863 56.3703 86.2279 510.6846 0.0000 1330.0000 0.0000 14.8585 510.6846 55.8528 70.7113 510.6514 0.0000 Page 3 0 U D Stage—Discharge Curve 'Wo 0.77 0.58 0.00 510.50 511.20 511.90 512.60 513.30 514.00 Stage — it Stage—Storage Curve 134Z'3 1077.70 808.28 0 � 538.85 269.43 510.50 51'.20 511.90 512.60 513.30 514.00 Stage — ft Multiple Hydrographs O -YEAR POST D'V"O-M'NT YEAR PRE DEVELOPMENT ib017:1:�:A111171. 602.00 784.00 966.00 1148.00 1330.00 Time — min 0.33 0.26 ti 0.20 JU 3 0.13 0.07 0.00 420.00 Multiple Hydrographs O -YEAR POST D'V"O-M'NT YEAR PRE DEVELOPMENT ib017:1:�:A111171. 602.00 784.00 966.00 1148.00 1330.00 Time — min