Key catchment Clarence Nymboida River at Mills Road

The Clarence River catchment is on the far north coast of NSW, situated around the city of Grafton; the catchment area of 22,716 square kilometres.


Bound in the west from Stanthorpe to Glen Innes by the Great Dividing Range (Northern Tablelands); by Baldblair, the Doughboy Ranges and the Dorrigo Plateau in the south; and by the MacPherson Ranges, which form part of the border with Queensland, in the north. The eastern boundaries are defined by coastal ranges from Coffs Harbour to Yamba, where the river enters the ocean and the Richmond Ranges north of Iluka. Generally the catchment is characterised in its western extremities by tableland areas which fall away to the relatively large, flat coastal floodplain.

Major towns

The river mouth is located between the towns of Yamba and Iluka, with the estuary reaching 108 kilometres inland to Copmanhurst. The towns of Grafton, Maclean, Yamba and Iluka are the main centres of population along the estuary, with Tenterfield and Dorrigo also located within the catchment.

Rivers and tributaries

The Clarence is the largest river on the east coast of NSW. It rises in the Macpherson Ranges on the NSW-Queensland state border, and flows south through an extensive coastal floodplain to Yamba, where it meets the Pacific Ocean. Major tributaries include the Mann, Nymboida and Orara Rivers.

Real-time flow data

The department monitors the conditions of river systems in NSW and provides regular updates on water levels, rainfall, water temperature and electrical conductivity.

View real-time data from the Clarence River catchment on this website.

Major water users

Beef cattle production is the catchment's main land and water user. Sugar cane, the dominant crop, is grown intensively on the lower Clarence, especially around Maclean, Harwood Island and Palmers Island. Other water use is by local councils and water utilities, forestry, dryland agriculture, aquaculture, prawn trawling, fishing and tourism.

Key water management issues

Key issues include riverbank erosion, gully erosion, invasive weeds, fire management practices and acid sulphate soils.

Due to a high density of rural settlement, the region's rivers and estuaries tend to be affected by changed run-off conditions caused by land clearing, agricultural use, human settlement and recreation. Many streams on the coastal floodplain have been straightened and channelled and sewage treatment plants discharge high volumes of nutrient rich water into the basin's river systems.

Most of the rivers and creeks in the Clarence River basin are unregulated, with no major storages to capture and control flows. Most water users rely on natural flows or small structures, such as weirs, for their water supplies. As in most unregulated rivers, flows are most affected during relatively dry times, when water is low and demand high.

Environmental values

The catchment enjoys a great diversity of vegetation types and wildlife habitats, with many areas protected in national parks, nature reserves and other types of reserves. Of particular ecological importance are the catchment's remnant rainforests, which are habitat areas of great species diversity.

A large proportion of the Clarence River catchment comprises national park (20%) and state forest (30%). These protected areas have helped to reduce human impacts on the river.

Water sharing plans

To preserve water resources in river and groundwater systems for the long term it is critical to balance the competing needs of the environment and water users. Water sharing plans establish rules for sharing water between the environmental needs of the river or aquifer and water users, and also between different types of water use such as town supply, rural domestic supply, stock watering, industry and irrigation.

Visit Water Sharing Plans.