# Notation

Ac
Area of the catchment, whole contributing drainage area (usually in m2)
Ap
Area of the practice e.g. footprint area of a bioretention cell (usually in m2)
d
Depth e.g. of an infiltration practice (units of length, usually m)
f
Eh?
L
Length, e.g. of a reach, channel or swale (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)
n
Manning's coefficient (unitless) (Note: for clarity porosity is being expressed as 'void ratio' and sharing the notation '
q
infiltration rate 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 swale gradient (length, usually m)
Rb
Rise of compensation gradient for an enhanced swale (length, usually m)
RVCT
Runoff volume control target (as outlined by MOECC, units are mm)
S
Slope
SCF
Safety correction factor (dimensionless)
VR
Void ratio, as usually applied to aggregates and yard materials. In this guide, is also applied to native soils in lieu of porosity (similarly dimensionless)
y
Depth of water (length, usually m or sometimes mm)