Rain Guardian Fortress

Compact, curb-adjacent pretreatment for highly urbanized bioretention sites.

The Rain Guardian Fortress is a reinforced concrete pretreatment chamber designed for installation in constrained right-of-way spaces, including curb bump-outs, streetscape projects, and other highly urbanized bioretention applications. Its compact footprint and modular design allow pretreatment without reducing surface green infrastructure area.

Product Overview

The Fortress is constructed from reinforced concrete with metal face plates that enable installation flush with the curb face. Its rectangular footprint of 48 inches by 18 inches allows it to fit in tight right-of-way locations while maintaining structural performance.

The unit is suitable for urban environments where space is limited, and its design allows straightforward maintenance and inspection access through removable metal grates.

Performance and Design Considerations

Hydraulic Performance
Designed overflow points ensure inflows are not restricted as water enters the bioretention practice.

• Inlet capacity: up to 4.12 cubic feet per second

• Outlet capacity: up to 7.85 cubic feet per second

• Internal storage volume: 1.36 cubic feet

Ponding Depth Flexibility
The Rain Guardian Fortress is designed for a standard 9-inch ponding depth. With minor field modifications, the unit can be installed in bioretention practices with both shallower and deeper ponding depths.

For shallower practices, a course of retaining wall block can be used adjacent to the chamber to achieve the proper installation elevation. For deeper practices, a gradual slope that is properly stabilized can be used to transition from the base of the Fortress to the base of the bioretention practice.