There are applications where water run off contains a lot of sediment. Such polluted water can cause issues in public sewers or in water treatment systems, which need de-sludged water to work properly. The optimised ACO Sedismart-G sedimentation system has an inner body that the precipitation water to be cleaned must flow around and through. This puts the water in the sludge trap into a rotational flow. Sedimentation of the solids is optimised by lengthening the flow time. The limits of the hydraulic efficiency of the optimised sedimentation systems were confirmed by an external expert using a hydrodynamic flow simulation. The optimised ACO Sedismart-G sedimentation system is about 25% more efficient than standard sludge trap.