A storm water management system and methods of assembling the same are provided. The system has open columns having corbels that support a slab spanning between adjacent columns. The system is assembled by positioning a first plurality of slabs end-to-end and spaced apart from a second plurality of slabs. The column is seated into an opening formed between the first and second plurality of slabs. A first corbel extends from a first side of the column and over laps an edge portion of a slab of the first plurality. A second corbel extends from a second side of the column and over laps an edge portion of a slab of the second plurality.