Nepean River Subcatchment
The Nepean River subcatchment is located downstream of the Upper Nepean subcatchment, which contains significant dams and protected water supply catchments, and joins the Hawkesbury River catchment at its confluence with the Grose River.
A significant section of the river, known as the Nepean Gorge, has the Greater Blue Mountains World Heritage Area on the east and west banks. The reserved lands on the west bank fall into the Erskine Creek subcatchment.
Outside the gorge, the floodplains and riparian zones have been extensively developed to support agricultural and rural-residential properties and there are also significant urban and industrial areas in this subcatchment, including the city of Penrith.
Stormwater, agriculture, mining and water extraction are all having adverse affects throughout the reaches.
There are 11 weirs located on the Nepean River that are singificantly regulating the natural flows. The river has been segmented into a series of ‘weir lakes' rather than a freely flowing river and is also impacted by dams in the Upper Nepean catchment.
There remains natural bushland in the lower reaches and isolated pockets in the mid reaches. Bents Basin State Conservation Area is one such example and is a popular recreational area for the people of Sydney.