A snapshot of the natural landscapes of the Sydney Metropolitan catchment includes:

• Woronora Plateau - headwaters of the Georges and Woronora Rivers
• Coastal and estuarine landscapes of the Georges, Woronora and Cooks Rivers
• Drowned river valleys and ridgelines of the Parramatta River, Middle Harbour and Sydney Harbour
• Sheer coastal cliffs of Manly and Watson's Bay
• North, South and Middle Heads, defining the entrance to Sydney Harbour
• Coastal bays, beaches, and sand dune systems, eg. Botany Bay
• Wetlands and lagoons
• The broad plains and low hills of the Cumberland woodlands.

Each of these landscapes contains distinctive and often sensitive ecosystems helping make the Sydney Basin the fifth most biodiverse region of Australia.

Sydney's natural environment is now one of the most threatened and extensively degraded:

• 90 per cent of riparian vegetation has been cleared;
• there are now 21 endangered ecological communities listed under the NSW Threatened Species Conservation Act,
• many coastal bays and estuaries are polluted and the sediments in some are highly toxic;
• salinity threatens infrastructure in western Sydney; and
• weeds continue to extensively displace native plants and threaten human health.