Stormwater Detention for a Compact Commercial Site

In Lake Elsinore, California, a new 7-Eleven replaced an unoccupied dirt lot, turning a permeable surface into an impermeable surface. Once that change occurs, stormwater must be managed.

To meet LID and BMP requirements, underground detention was required, and with the site located near a freshwater lake, added water quality measures like onsite biofiltration and catch basin inserts were incorporated into the design.

The StormVault detention system had to fit within a tight footprint already constrained by additional underground storage systems for fuel.

The system also needed to meet AASHTO HL-93 loading for constant vehicle traffic and regular fuel deliveries, while tying into a broader site design that included an onsite biofiltration vault. Space was limited, but performance requirements weren’t.

A precast StormVault system using a segmental Type 1 box culvert design provided compact, underground detention without impacting the surface layout.

The system spans 120 feet and measures 12′ wide by 6′ high, delivering about 9,000 cubic feet of storage through 16 bottom sections, 16 top sections, and two end walls.

Precast catch basins with insert filters capture and treat runoff before it enters the onsite biofiltration system, then flows into the detention system, which eventually discharges toward the lake.

Got a project coming up you want to chat about? Contact Jensen Infrastructure today.