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~P• ~ <br /> <br />s <br /> <br />Worksheet 3: Time of concentration (Te) or travel time (TL) <br />Project ~rl '~ /)'~.ne 13y J~.UJ. Date /o-b-~'~- <br />Location (/ a f~ DHryP Check/ed Date <br />Circle one: Present Developed ~~ahNed <br />Circle one: To TC [lirough subarea <br />NOTES: Space for as many as two segments per flow type can be used for each <br />worksheet. <br />Include a map, schematic, or description of flow segments. <br />Sheet flow (Applicable to To only) Segment ID <br />1. Surface description (table 3-1) ............ <br />2. Manning's roughness coeff., n ([able 3-1) .. <br />7. Flow length, L (total L < 300 ft) .......... ft <br />4. Two-yr 24-hr rainfall, PZ .................. in <br />5. Land slope, s .............................. Et/f[ <br />6. Tt 0.00075(nL0)0'8 Compute Tt ,,,,,, hr <br />P2 s <br />Shallow concentrated flow Segment ID <br />7. Surface description (paved or unpaved) ..... <br />8. Flow lengxh, L ............................. ft <br />9. Watercourse slope, s ....................... ft/ft <br />10. Average velocity, V (figure 3-1) ........... ft/s <br />11. Tt - 3600 V Compute Tt ...... hr <br />Channel flow Segment ID <br />12. Cross sectional flow area, a ............... ft2 <br />13. We[[ed perimeter, pw ....................... ft <br />14. Hydraulic radius, r = Pa Compute r ..,.... ft <br />w <br />15. Channel slope, s ........................... ft/ft <br />16. MannSng's roughness coeff., n .............. <br />2/3 1/2 <br />17. V 1.G9 r s Compute V ....... ft/s <br />n <br />18. Flow length, L ............................. ft <br />19. Tt 7600 V Compute Tt ...... hr <br />20. Watershed or subarea Tc or Tt (add Tt in steps 6, 1 <br />' /-~ <br />Greve 1 <br />D.D ll <br />300 <br />/~ <br />o, zs <br />m.o3 + <br />_ <br />_ <br />+ _ <br />, and 19) ....... hz ~' 0.3 <br />