JMA02P003 262 270 Main Street Development Stormwater Management Report

Proposed Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Pond 2P: Basin A - Chamber Wizard Field A Chamber Model = Cultec R-180HD (For residential use only) Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.33'L = 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.33'L with 1.00' Overlap Row Length Adjustment= +1.00' x 3.44 sf x 8 rows 36.0" Wide + 6.0" Spacing = 42.0" C-C Row Spacing 11 Chambers/Row x 6.33' Long +1.00' Row Adjustment = 70.63' Row Length +12.0" End Stone x 2 = 72.63' Base Length 8 Rows x 36.0" Wide + 6.0" Spacing x 7 + 12.0" Side Stone x 2 = 29.50' Base Width 6.0" Stone Base + 20.5" Chamber Height + 6.0" Stone Cover = 2.71' Field Height 88 Chambers x 21.8 cf +1.00' Row Adjustment x 3.44 sf x 8 Rows = 1,943.5 cf Chamber Storage 5,802.8 cf Field - 1,943.5 cf Chambers = 3,859.4 cf Stone x 40.0% Voids = 1,543.8 cf Stone Storage Chamber Storage + Stone Storage = 3,487.2 cf = 0.080 af Overall Storage Efficiency = 60.1% Overall System Size = 72.63' x 29.50' x 2.71' 88 Chambers 214.9 cy Field 142.9 cy Stone