Laserfiche WebLink
71ME OF CONCENTRATIOk <br />IMPERVIOUS AREAS <br />Sheet Flow (Appllca6le to Tc only) <br />SuAace Description <br />Manniny's Roughness Coefficient, nsheet <br />Flow Lengih (L<=300'). Lsheet <br />2-Year, 24-Hour Rainfall, P2 <br />Land Slope, Ssheet <br />Tt Sheet <br />Tt Sheet <br />Shallow Concentrated Flow (See DOE SWM <br />Surface Description <br />Flow Length, Lshallow <br />Watercourse Slope, So <br />Time of Concentration Velocity Factor, k _ <br />Average Velocity, Vshallow = k x So"0.5 <br />Tt Shallow <br />Tt Shallow <br />Channel Flow (See DOE SWM Manual, Page <br />Type ot Channel <br />Flow Length, Lchannel <br />Watercourse Slope, So _ <br />Time of Concentration Velocity Factor, kc <br />Average Velocity, Vchannei = k x So"0.5 <br />Tt Channel <br />Tt Channei <br />Results: Watershed or Subarea Tc or Tt <br />Total Tc or Tt <br />Total Tc or Tt <br />Minimum Tc Used in Basin File <br />Pavament <br />0.011 <br />15 fPet <br />1.50 inches <br />o.ozoo wn <br />0.01 hours <br />0.39 min. <br />Pavement <br />54 ft <br />0.0900 ft/ft <br />27.00 <br />8.10 fps <br />0.00 ours <br />0.11 min. <br />s fl1-1-15, 111-1-16J <br />Storm Drain <br />276 ft <br />_ - - - 0.0170 ft/ft <br />42.00 <br />- - - ---- - — 5.48 fps <br />0.01 hours <br />0.84 min. <br />0.022 hours <br />1.338 min <br />6.000 min <br />Note: <br />1. Worksheet based on time equations from Stormwater Managemert Manual for the <br />Puget Sound Basm, Chapler III <br />MaplewoodDetCalc els � 0 8�9�2007 <br />