POST DEV NOAA 24-hr D 100 YEAR Rainfall=9.48" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 89
Pond 8P: SSIB #2 UNDERGROUND - Chamber Wizard Field A
Chamber Model = ADS N-12 24" (ADS N-12® Pipe) Inside= 23.8"W x 23.8"H => 3.10 sf x 20.00'L = 62.0 cf Outside= 28.0"W x 28.0"H => 3.92 sf x 20.00'L = 78.4 cf 28.0" Wide + 13.4" Spacing = 41.4" C-C Row Spacing 3 Chambers/Row x 20.00' Long +2.33' Header x 2 = 64.67' Row Length +10.0" End Stone x 2 = 66.33' Base Length 12 Rows x 28.0" Wide + 13.4" Spacing x 11 + 10.0" Side Stone x 2 = 41.95' Base Width 4.0" Stone Base + 28.0" Chamber Height + 4.0" Stone Cover = 3.00' Field Height 36 Chambers x 62.0 cf + 40.28' Header x 3.10 sf x 2 = 2,481.8 cf Chamber Storage 36 Chambers x 78.4 cf + 40.28' Header x 3.92 sf x 2 = 3,137.9 cf Displacement 8,348.3 cf Field - 3,137.9 cf Chambers = 5,210.4 cf Stone x 40.0% Voids = 2,084.2 cf Stone Storage Chamber Storage + Stone Storage = 4,565.9 cf = 0.105 af Overall Storage Efficiency = 54.7% Overall System Size = 66.33' x 41.95' x 3.00'
36 Chambers 309.2 cy Field 193.0 cy Stone