Firstly, all three zones will be sized together within the limited depth to estimate the footprint area of the whole [[bioretention]] facility. To do this the mean void ratio (''V<sub>R</sub>'') will estimated as ~ 0.35. | Firstly, all three zones will be sized together within the limited depth to estimate the footprint area of the whole [[bioretention]] facility. To do this the mean void ratio (''V<sub>R</sub>'') will estimated as ~ 0.35. |