Permeable Pavement Stormwater Cutaway

This simulator shows a 3D cutaway of a permeable-pavement stormwater system: porous pavers, a choker course, an open-graded stone reservoir course and the native subgrade beneath. Rainfall enters through the surface at a rate capped by how clogged the pore structure is, fills the stone reservoir's void space, and drains out the bottom at the subgrade's own infiltration rate. Push the storm harder than the surface or the subgrade can handle and the excess bypasses the system as visible surface runoff — the same two failure modes (surface clogging and an undersized or slow-draining reservoir) that govern real permeable-pavement design.