# Notation

L
Length, e.g. of a reach, channel or swaleA 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. (usually in m)
m
run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. where side side slopes = 1:3.5, m = 3.5)
q
infiltration rateThe rate at which stormwater percolates into the subsoil measured in inches per hour. in (length per time, usually mm/hr) (before or after application of safety factor?)
Qp
Peak flow in units of volume per time (e.g. m3/s)
Ra
Existing rise of swaleA 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. gradient (length, usually m)
Rb
Rise of compensation gradient for an enhanced swaleVegetated open channel, with check dams; designed to convey, treat and attenuate stormwater runoff. (length, usually m)
SCF
Safety correction factor (dimensionless)
y
Depth of water (length, usually m or sometimes mm)