🕳️ Arch Infiltration Chambers (Cultec / StormTech) + 40% Clean Stone Void Storage

Underground Stormwater Retention Chamber Calculator

Size subsurface plastic arch retention and detention chamber arrays beneath commercial parking lots: calculate combined storage capacity (chamber internal volume plus 40% open pore space in AASHTO No. 57 crushed stone bedding), geotextile wrap encapsulation, inspect/flush manifold rows, and underground utility contracting margins.

1. Project & Operating Inputs

Required Retention Volume (Cubic Feet e.g. 45,000 Cu Ft / 336,000 Gal)

Chamber Model Unit Volume (Cu Ft / Chamber e.g. 75 Cu Ft Arch Chamber)

Customer Bid Price for Supplied & Landed Subsurface Chamber Bed ($)

Polypropylene Arch Chambers, Clean Stone Ballast, Woven Fabric & Labor ($)

2. Financial Breakdown & Yield

SUBSURFACE STORMWATER RETENTION

Turnkey Underground Retention Profit

Civil Stormwater Contractor Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Material Cost