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Ri;TP�1`iTION SISTEPI i'OR PUGiT SOUIvTD IC.u.IJ�Y CLItiIC <br />STL•'P 1 <br />Predevelopment: <br />Unimprov«�d area 16,3G0 ft2 C=.10 <br />Side slope, earth 1 3�0 ftz C=.60 <br />18,240 ft2 Eff C=.14 cxist <br />Postdevelopment: <br />Pavement and roofs <br />Lawns aud planting <br />11,837 ft2 <br />6,403 ft2 <br />13,2�0 ft2 <br />C=.90 <br />C=.17 <br />Lff C=.64 dev <br />ST�P 2 <br />Dist_ance to proposed outlet, 120' (appro:t.) <br />Percent of slope, 1% <br />From table, L'igure 1 <br />pfostly bare ground <br />Velocity equals 1 ft/sec, tlierefore <br />Tc= 120 + 10 = 12 :ninutes <br />(1 n0 <br />ST�P 3 <br />Fr.om Figure 2, intensitl� "i", = 1.7 in/hr. <br />STEP 4 <br />Tributary area = 1II,2�0 it2 or <br />STr�P 5 <br />Rallow = �exist.l �� <br />4137 acres <br />Qallow = (.14)(1.7)(.4137) _ .0996 ft3/sec. <br />STEP 6 <br />�dev = .G4 <br />Qo = Qa71ow__ _ <br />(A)(�dev) <br />T = -`5 + � <br />3716 <br />.09^„i = .371G <br />(.41J7)(.G4) <br />= 52.II8 min. <br />