Stormwater from the immediate vicinity can
be directed overland to the structural soil or
flow through porous pavement or turf directly
into the specialized base course. The amount of
water structural soils are able to treat is dependent on the depth of the reservoir. For example,
24 inches (61 cm) of CD-Structural Soil will
accommodate 6.25 inches (16 cm) of rain within
a twenty-four-hour period, based on a known
void space of 26 percent (Haffner and Bassuk
2007). Many different structural soil manufacturers exist. The performance of each system
varies and is largely dependent on the materials
mix, as well as the installation and maintenance
practices. Structural soils are typically designed
to drain within forty-eight hours to protect the
health of the vegetation and maintain optimal
function (Day and Dickinson 2008). Excess
water can overflow into a secondary bio filtration
treatment feature or storm sewer.
.