 The State Planning Policy Framework of the [Victoria Planning Provisions] which is contained in all planning schemes in Victoria contains some specific clauses requiring adoption of WSUD practices.New residential developments are subject to a permeability standard that at least 20 per cent of sites should not be covered by impervious surfaces.The objective of this is to reduce the impact of increased stormwater run-off on the drainage system and facilitate on-site storm-water infiltration.