Line 5:
Line 5:
[[File:Sizing bio1.png|thumb|The three storage areas 'bowl', 'filter media' and 'reservoir' are sized together.]]
[[File:Sizing bio1.png|thumb|The three storage areas 'bowl', 'filter media' and 'reservoir' are sized together.]]
The bioretention facility will comprise three vertical zones:
The bioretention facility will comprise three vertical zones:
#a 'bowl' permitting water to pond occasionally,
#a 'bowl' permitting water to pond occasionally (maximum depth,''d<sub>p</sub>''= 0.5 m)
#a layer of [[filter media]] to support plant growth, and
#a layer of [[filter media]] to support plant growth (minimum depth,''d<sub>m</sub>'' = 0.6 m) , and
#a reservoir of [[stone]] to store and facilitate [[infiltration]] of additional water.
#a reservoir of [[stone]] to store and facilitate [[infiltration]] of additional water (depth,''d<sub>R</sub>''includes 0.1 m choking layer).
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.