Changes

;f':Design infiltration rate (length per time, usually mm/hr) after application of safety correction factor (SCF)

;f':Design infiltration rate (length per time, usually mm/hr) after application of safety correction factor (SCF)

;h :height (units of length)

;h :Height (units of length)

;i :Intensity of the design storm event (in units of depth/time, usually mm/hr)

;i :Intensity of the design storm event (in units of depth/time, usually mm/hr)

;L :Length, e.g. of a reach, channel or swale (usually in m)

;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. side slopes = 1:3, so m = 3)

;m :Run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. side slopes = 1:3, so m = 3)

;n :Porosity, applies to aggregate and other void-forming materials, filter media and native soils (unit is vol/vol, so dimensionless)

;n :Porosity, applies to aggregate and other void-forming materials, filter media and native soils (unit is vol/vol, so dimensionless)

;Q_p :Peak flow in units of volume per time (e.g. m³/s)

;Q_p :Peak flow in units of volume per time (e.g. m³/s)

;R :Ratio of catchment (A_c) to the practice footprint area (A_p). ''syn.'' I/P ratio. For [[green roofs]] (and often permeable paving systems) this will be 1:1. In [[bioretention]] it may be 15 or 20 to 1.   

;R :Ratio of catchment impervious area (A_i) to the practice footprint area (A_p). ''syn.'' I/P ratio. For [[green roofs]] and often [[permeable paving]] systems that do not receive drainage from external impervious areas this will be 0. For [[bioretention]], [[infiltration trenches]] and [[infiltration chambers]] receiving pavement runoff, it is recommended to be kept between 15 to 20.   

;R_a :Existing rise of swale gradient (length, usually m)

;R_a :Existing rise of swale gradient (length, usually m)