A catchment is the area of land that drains into a waterway. Gravity causes all rain and run-off in the catchment to run downhill where it naturally collects in creeks, rivers or oceans. In natural areas rainwater is absorbed into the landscape by plants, trees and soil, filling the groundwater system (underground water). In an urban river catchment such as our City, most surfaces are hard and impermeable. Rainwater runs off roofs, roads and footpaths becoming stormwater which picks up pollution and debris along the way.

Our City is part of three main catchment areas with water flowing into the Cooks, Georges and Parramatta rivers. These rivers are fed by smaller tributaries, including:

• Prospect creek (Lansdowne);
• Duck River (Sefton);
• Saltpan Creek (Padstow);
• Little Saltpan Creek (Revesby);
• Cup and Saucer Creek (Clemton Park); and　
• Wolli Creek (Earlwood).　

Council conducts environmental improvement works and programs at many sites within our catchment to improve river and catchment health. This includes stormwater management projects, the installation of various pollution control devices and water sensitive urban design. It also includes programs like the Get the Site Right compliance campaign targeting sediment and erosion control on building and development sites.

Council also works closely with other councils on catchment management through its active membership in the Cooks River Alliance, Georges Riverkeeper and Parramatta River Catchment Group. Council is currently working with these groups on the development of the following catchment management programs:

• Cooks River Catchment Coastal Management Program
• Georges River Coastal Management Program (updates the existing Georges River Estuary Coastal Zone Management Plan)
• Greater Sydney Harbour Coastal Management Program (includes Parramatta River catchment area)