The Lower Hawkesbury-Nepean River catchment covers 12,000 square kilometres, extending from Picton in the South, Blacktown in the East, to Rylstone in the north West, and almost to Singleton in the North.

The Hawkesbury Nepean river system is effectively divided into upper and lower catchments. The Upper Catchment, upstream of Warragamba Dam is dealt with under a separate regional page. This region includes the area below the Warragamba Reservoir.

Main towns:

• Camden
• Glen Davis
• Penrith
• Putty
• Windsor