Feedback post on Infiltration trenches

C.Davidson, Golder Associates - The Wiki says "Void Ratio of 0.4", but the Stormtech reference cited says "Porosity of 40%". These are not the same number. -Porosity = Volume of Voids / Total Volume of Material -Void Ratio = Volume of Voids / Volume of Solids For clearstone layer with 40% porosity, should not void ratio be 40% / 60%, or 0.67? SWMM5 also gives "Typical values range from 0.5 to 0.75 for gravel beds"