The water resources crisis facing countries of the Mediterranean Basin is reflected, in diminished form, in the semi-arid, “Mediterranean-climate” zone of Australia. Some creative solutions involving the collection, treatment, storage, retrieval and use of storm runoff to replace the component of mainssupplied water presently used for “second quality” purposes, are emerging in Adelaide, capital city of South Australia. The paper describes one initiative being taken to achieve source control of stormwater – quantity and quality – in mixed-density residential streets. The resulting streetscape is suitable for use in both “greenfields” and re-development projects. The paper explores the hydrological/hydraulic performance of the system and shows that it satisfies all theoretical- requirements for safety in the full range of flooding up to and including the “once in 100-years” event. The new streetscape holds the following advantages over conventional streetscapes : reduced peak outflows, greatly improved effluent water quality, aids “greening” of the landscape, potential for aquifer recharge where appropriate, aquiferretrieved groundwater can replace mains water used for irrigation, “nuisance” flows are fully contained (no surface appearance), major flows only occupy the swale, street residences are less flood prone and the streetscape fits more harmoniously into undulating terrain.