Notation

q

infiltration rate in units of length per time. (before or after application of safety factor?)

SCF

Safety correction factor (dimensionless)

R_a

Existing rise of swale gradient

The rate at which stormwater percolates into the subsoil measured in inches per hour.

A shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades.