PERMFILE117357

• Permit No: M1988112
• IBM Index Class Name: Permit File
• Doc Date: 11/8/1988
• Section_Exhibit Name: APPENDIX H DRAINAGE AREAS AND WASHED PRINTOUTS
• Media Type: D
• Archive: No

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TABLE H.2 (con't)
RIPRAP SIZING
Rito Seco Crossino
3-54" CMP each conveys 180 cfs
Q/Oz.s = 180/4.5z.s = 4.2 < 6.0
Q/D~.s = 18.9
Fig 5-7 yields
Y~/D = 0.40
Q/Dz.s = 4.2
Type H riprap - 18" dso
Fig 5-7 1 = 3.25
YL/D = 0.4 2 tan e~
use V = 5.5 A~ = Q/V = 32.7
YL = 0.4 x 4.5 = 1.8
W=D=4.5
so L = (3.25)(32.7/1.8 - 4.5) = 44.4', say 50'
Summary:
- 18" dso riprap
- placed to 50' d/s of culvert outlet
- riprap placed to 36" thickness in channel invert
21" thickness on channel side slopes