Key catchment Macdonald River

The Namoi River is one of the Murray-Darling Basin's major sub-catchments in New South Wales. The Peel River is a major regulated tributary to the Namoi. The town of Tamworth on the Peel River, is the largest urban centre in the catchment.


Namoi locality map

Located in north-western NSW, the Namoi catchment borders the Gwydir and Castlereagh catchments and is bound by the Great Dividing Range in the east, the Liverpool Ranges and Warrumbungle Ranges in the south, and the Nandewar Ranges and Mount Kaputar to the north. Elevations range from over 1,500 metres to the south and east, to just 100 metres on the alluvial floodplain of the lower catchment west of Narrabri.

Catchment area

The Namoi catchment includes its major regulated tributary the Peel River. Catchment area is about 42,000 square kilometres from the Great Dividing Range near Tamworth, to the Barwon River near Walgett. It is over 350 kilometres long, stretching from Bendemeer in the east to Walgett on the western boundary.

The Peel River has a catchment area of around 4,700 square kilometres and contributes an average annual volume of approximately 280,000 megalitres to the Namoi River.

Major towns

Tamworth, on the Peel River, is the largest urban centre. The smaller towns, Gunnedah and Narrabri are on the Namoi River. There are a number of additional smaller towns throughout the catchment, such as Barraba, Boggabri, Manilla, Quirindi, Walgett, Wee Waa and Werris Creek.

Rivers and tributaries

The Namoi River rises in rugged ranges near Tamworth, forming a complex pattern of creeks and streams before joining the Barwon River at Walgett. Its main tributaries are the Manilla and Peel rivers, joining the Namoi upstream of Boggabri, and Coxs, Pian, Narrabri, Baradine and Bohena creeks joining below Boggabri. The river has developed an extensive floodplain, with around a quarter of the basin prone to flooding.

Major tributaries of the Peel River are Goonoo Goonoo Creek, Cockburn River, and Dungowan Creek.

Real-time flow data

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

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

Major water storage

Keepit Dam, with a capacity of 426,000 megalitres, is the major irrigation storage for the Namoi catchment. Split Rock Dam – 397,000 megalitres, augments the supply from Keepit Dam as well as supplying users along the Manilla River. Chaffey Dam, with a 62,000 megalitres capacity, regulates the flow of the Peel River and augments water supply to Tamworth.

Major water users

The Namoi River and Peel River systems are operated separately from a water resource management perspective, with water users including local councils and water utilities, dryland agriculture, irrigated agriculture (cotton), livestock grazing and forestry.

The major water users in the Namoi River system are general security irrigators, the two main water users in the Peel River system being Tamworth City Council and general security irrigators.

Key water management  issues

Sharing water fairly between competing water users and the environment, within the extraction limits set by the Murray-Darling Basin Cap, is a key water management issue. Water sharing plans address this issue by setting long-term rules on how water can be accessed, used and traded. The management of floodwaters is an ongoing challenge.

Floodwaters play a vital role in sustaining and replenishing the landscape, but are also highly valued by local agricultural users. The NSW Office of Water is developing a floodplain harvesting policy to better manage floodwater diversion across the state.

The alteration of natural river flows through the construction of dams and weirs, and erosion from land clearing, affect riverine health and contribute to water quality problems, such as salinity.

Environmental values

The Pilliga Scrub is the largest remaining dry sclerophyll forest west of the Great Dividing Range in NSW. Pilliga Nature Reserve and Pillga State Conservation Area together protect over 1,800 square kilometres of this semi-arid woodland.

Downstream of Narrabri there are many small lagoons, wetlands, and anabranches associated with the river, and extensive areas of floodplain woodlands on the floodplain.

Lake Goran is a large internally draining basin that covers more than 60 square kilometres. When flooded, the lake provides habitat for large numbers of waterbirds, and is listed as a wetland of national significance.

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.

Water sharing plans in this catchment:

  • Namoi Unregulated and Alluvial Water
  • NSW Great Artesian Basin Groundwater
  • NSW Great Artesian Basin Shallow Groundwater
  • NSW Murray-Darling Basin Fractured Rock Groundwater
  • NSW Murray-Darling Basin Porous Rock Groundwater
  • Peel Valley Regulated, Unregulated, Alluvium and Fractured Rock
  • Upper and Lower Namoi Groundwater
  • Upper Namoi and Lower Namoi Regulated River

Visit water sharing plans for a status update.

Under the Water Management Act 2000 all water sharing plans are required to have performance indicators to assess whether the plans have been effective in meeting their objectives. The Environmental flow response and scoio-economic monitoring. Namoi Valley progress report 2009 (PDF, 7071.74 KB) summarises activities undertaken in the previous water year and provides an interim assessment of outcomes from the investigations.