18087 03-29-21 Sediment Pond Calcs

Date: Design: Norris & Tunstall Wilmington, NC Sheet:
3/29/2021 TJS Consulting Engineers, P.C. Brunswick County, NC 1
Check: Job: For: Job#:
JPN Sediment Pond Calculations Benton Tract Sand Mine 18087
Limit of Disturbance
329141 sf 7.56 ac
Required Storage = 1800 cf/ac dist. = 13601 cf
Required Area =435 sf/cfs Q10 = 4733 sf
Q10= CxixA= 10.9cis
C = 0.2
i = 7.2 in/hr
A = 7.56 ac
Elev ft Area sf Vol cf
37 3308 0
38 4363 3823
39 5476 4908
40 6644 6050
Total 14781
Provided Area = 6644 sf
Provided Volume= 14781 cf
L/W Ratio= 4
Depth = 3 ft
�ttllilR,hy,
Outlet Pipe
2P
Size= 15 in
Q= CiA= 10.9 cfs
C= 0.2 1
l
i = 7.2in/hr
A= 7.56 ac
Vel. =Q/A pipe= 8.87 ft sec
A pipe = 1.23 sf
Vel. >2.0 ft/sec
10'x10'x1' Rip Rap
Energy Dissipater