Laserfiche WebLink
Illumination Foundation <br />Santa Ana, California <br />Hydrology Report <br />by TAIT & Associates <br />TAIT JOB # SP9104 Page 5 <br />The drainage pattern differs a bit from the existing to proposed condition where the proposed <br />condition is diverting some flows from outfall 2 and re -directing them to outfall 1. The drainage <br />pattern differs in the proposed condition due to the addition of drain inlets where previously <br />outfall 2 in the existing condition doesn’t contain any drainage structures and diverts flows to <br />the easterly and southerly property lines. See below for Outfall 1 & 2 s ummary and explanation. <br />Outfall 1 sees a decrease in peak flows of roughly 0.7% in the 25-yr and 0.7% in the 100-year. <br />This should be considered a negligible difference and will not cause any flooding to the existing <br />or proposed habitable structures. <br />In extreme storm scenarios the site will pond and runoff over the existing south easterly <br />driveway entrance to the site with a low point of 80.69’ along the right-of-way. The highest <br />point located at the right-of-way is 81.56’ and is also the established BFE elevation based on the <br />Area ID Area (sf) Area (ac) Pervious <br />Area (SF) <br />Pervious <br />Area (AC) <br />Impervious <br />Area (SF) <br />Impervious <br />Area (AC) <br />Percent <br />Impervious Soil Type 25 YR PEAK <br />FLOW (cfs) <br />100 YR PEAK <br />FLOW (cfs) <br />DA A-1 22,301 0.512 3968 0.091 18333 0.421 82.2 A 1.84 2.37 <br />DA A-2 15,612 0.358 5937 0.136 9675 0.222 62.0 A 1.27 1.64 <br />ATOT 37,913 0.870 9905 0.227 28008 0.643 73.9 A 3.11 4.01 <br /> EXISTING DMA SUMMARY <br />Area ID Area (sf) Area (ac)Pervious <br />Area (SF) <br />Pervious <br />Area (AC) <br />Impervious <br />Area (SF) <br />Impervious <br />Area (AC) <br />Percent <br />Impervious Soil Type 25 YR PEAK <br />FLOW (cfs) <br />100 YR PEAK <br />FLOW (cfs) <br />DA A-1 2,630 0.060 230 0.005 2,400 0.055 91.3 A 0.26 0.33 <br />DA A-2 2,079 0.048 1,472 0.034 607 0.014 29.2 A 0.19 0.24 <br />DA A-3 539 0.012 - 0.000 539 0.012 100.0 A 0.05 0.07 <br />DA A-4 3,362 0.077 1,478 0.034 1,884 0.043 56.0 A 0.27 0.36 <br />DA A-5 22,503 0.517 3,898 0.089 18,605 0.427 82.7 A 1.86 2.39 <br />DA A-6 6,800 0.156 1,926 0.044 4,874 0.112 71.7 A 0.55 0.71 <br />ATOT 37,913 0.87 9004 0.207 28909 0.664 76.3 A 3.09 3.98 <br /> PROPOSED DMA SUMMARY <br />AREAS <br />25-YR <br />(CFS) <br />100-YR <br />(CFS) <br />A-1 3.11 4.01 <br />A-1-A-5 3.09 3.98 <br />AREAS <br />25-YR <br />(CFS) <br />100-YR <br />(CFS) <br />A-2 1.27 1.64 <br />A-6 0.56 0.71 <br />OUTFALL 1 SUMMARY (36" CATCH BASIN) <br />OUTFALL 2 SUMMARY (EASTERLY PL LS PLANTER) <br />EXISTING CONDITION <br />PROPSED CONDITION <br />EXISTING CONDITION <br />PROPSED CONDITION <br />914-918 N Bewley <br />St5/8/2025