Namoi catchment

Water managers will respond to catchment conditions to determine use of water for the environment in the Namoi, with a likely focus on native fish recovery.

Bridge across the tree-lined Namoi River on Kamilaroi Highway, East of Wee Waa

The Namoi catchment covers an area of approximately 42,000 square kilometres.
The Namoi and Peel rivers are regulated, with major water storages being Keepit, Split Rock and Chaffey dams. Significant environmental values in the catchment include the Namoi River between Gunnedah and Narrabri which provides critical habitat for native fish and threatened species.

Also, many small lagoons, wetlands and anabranches on the floodplain downstream of Narrabri provide habitat for waterbirds. Lake Goran, in the unregulated Mooki catchment, is listed as a wetland of national significance.

The Namoi catchment wetlands and rivers also support important Aboriginal cultural values for the Kamilaroi (Gomeroi) people.

Water for rivers and wetlands

Improved weather conditions and return of natural river flows at the end of 2020–21 continued into 2021-22 with large scale floods occurring in December. No water for the environment was delivered during the year as dam spills, combined with downstream tributaries, provided for environmental demands in the Lower Namoi and Peel rivers. Large end-of-system flows also contributed to environmental water demands in the Barwon-Darling River.

With ongoing support of natural inflows, water managers will respond to catchment conditions to determine the most appropriate use of water for the environment. It is likely water managers will continue to support native fish recovery, particularly below Wee Waa. In the year ahead, water managers will focus on providing movement and dispersal opportunities for native fish in the system.

Management of water for the environment in the Peel Valley will continue to focus on in-channel productivity, habitat quality and native fish drought recovery upstream of Tamworth. Water managers will likely deliver flows in spring.

Weather and water forecast

The El Niño–Southern Oscillation (ENSO) outlook remains at La Nina, with a return to neutral ENSO during winter. However, atmospheric indicators remain above La Nina threshold, meaning the La Nina influence continues.

The short-term rainfall outlook is likely to be above median for the Namoi which will maintain the current soil moisture and run-off efficiency within the catchment.

Water managers have prepared watering plans that consider a range of weather and water availability scenarios. This is known as resource availability scenario planning. As dam levels remain moderate, a significant degree of uncertainty remains around resource availability. However, on balance, the Namoi catchment outlook is rated as ‘wet’.

1. ENSO: The interaction between the sea surface and atmosphere over the Pacific Ocean which results in dryer or wetter conditions (El Nino or La Nina).

Resource availability scenario

 Dry river reaches in lower Mehi near Collarenebri gauge 2

Very dry

Main aim: Protect

Avoid critical loss
Maintain key refuges
Avoid catastrophic events

 Red Gum, "Hells Gate", now called "Black Rocks", Darling River

Dry

Main aim: Maintain

Maintain river functioning
Maintain key functions of high priority wetlands

 Macquarie River Trail, Dubbo

Moderate

Main aim: Recover

Improve ecological health and resilience
Improve opportunities for plants and animals to breed, move and thrive

 Lower Murray

Wet to very wet

Main aim: Enhance

Restore key floodplain and wetland linkages
Enhance opportunities for plants and animals to breed, move and thrive

Key planned actions for 2022–23

 

Waterbird icon

Waterbirds

Water managers have no specific action planned. They expect an improvement in the diversity and abundance of waterbirds in response to natural flooding of warrambools, high floodplain and riparian vegetation.

Refuge pools will support some minor waterbird habitat.

Native fish icon

Native fish

Water managers will look for opportunities to help support the recovery of native fish populations.

Native vegetation icon

Vegetation

Overland flow from recent flooding events will support riparian and floodplain vegetation as will areas where regulated flows extend.

Connectivity and water flow icon

 Connectivity

Water managers will look for opportunities to provide connection with the Barwon River to encourage dispersal of native fish into the Namoi River.

Figure 1 Map of proposed annual priority targets in the Namoi Water Resource Plan area 2022–23.

Map of the Namoi Water Resource Plan area 2022–23

The Department of Planning and Environment (the department) is supporting the health and resilience of rivers and wetlands by delivering water for the environment where and when it is needed. We use the best available science, management expertise and experience to manage water across the landscape. This statement of annual priorities identifies the waterways and wetlands that are likely to receive water.

Our decision-making process considers:

  • expected availability of water in the coming year
  • conditions of the previous year
  • current health of the plants and animals in these ecosystems.

The NSW Government works with the Commonwealth Environmental Water Holder to manage water in the catchment.

First Nation objectives in the catchment are outlined in the Aboriginal Environmental Water Priorities.


Water for the environment is a share of the water in dams and rivers that is set aside to support the long-term health of local rivers, creeks and wetlands. Healthy rivers carry water to homes, farms, schools and businesses. Rivers and wetlands are important cultural and spiritual sites for Aboriginal people, as well as the broader community.

Source

Maximum volume available (megalitres – ML)

Volume expected 1 July under current conditions (megalitres – ML)

Planned environmental water

 

Environmental Water Allowance

5,000 ML

3,350 ML

Peel water licenced to the Commonwealth

 

General security

1,257 ML

842 ML

Upper Namoi licenced to the Commonwealth

General security

105 ML

105 ML

Lower Namoi licenced to the Commonwealth

General security

13,548 ML

14,256 ML

Notes: This is an indicative summary of expected volumes to be available. For further detail and information on available volumes please contact the region via Department of Planning and Environment enquiries on 1300 361 967.

1 gigalitre = 1000 megalitres; 2.5 megalitre = 1 Olympic swimming pool.