*V<sub>i</sub> = Infiltration volume target for the design storm event (m<sup>3</sup>)
*V<sub>i</sub> = Infiltration volume target for the design storm event (m<sup>3</sup>)
*A<sub>p</sub> = Surface area of the practice (m<sup>2</sup>, see equations above to calculate for designs that deliver water to a surface ponding area vs. directly to storage reservoir.
*A<sub>p</sub> = Surface area of the practice (m<sup>2</sup>), see equations above to calculate for designs that deliver water to a surface ponding area vs. directly to storage reservoir.
*f' = Design infiltration rate of the underlying native soil (m/h)
*f' = Design infiltration rate of the underlying native soil (m/h)