Annual environmental water priorities in the Border Rivers catchment 2023–24

Water that is allocated and managed specifically to improve the health of rivers, wetlands and floodplains is known as water for the environment.

NSW environmental water management teams work with local communities, Aboriginal representatives, partner agencies, and other stakeholders to develop detailed annual plans for the use of water for the environment in each catchment, including how its use is prioritised.

The catchment

The NSW Border Rivers catchment covers an area of 24,000 km². The catchment hugs the Queensland border and is influenced by the management of water on both sides of the border.

Pindari Dam, on the Severn River (NSW), and Glenlyon Dam, on Pike Creek (Queensland), are 2 of the major water storages influencing the catchment. Morella Watercourse, Boobera Lagoon and Pungbougal Lagoon located on the Macintyre River floodplain are important cultural sites for Aboriginal people. These wetlands are also listed as a site of national importance in the Directory of Important Wetlands in Australia.

The Border Rivers catchment is Country to the Bigambul, Euahlayi, Githabul, Kambuwal, Gomeroi/Kamilaroi, Kwiambul, and Ngarabal Aboriginal people.

Water for rivers and wetlands

Following wet years in 2021 and 2022, the weather outlook for 2023 is dry and warm, signalling a possible return to dry conditions.

Flow records show that despite recent wet years, base flows needed to continue for a longer period to achieve ecological connectivity with the Barwon River. Similarly, large freshes are not being observed often enough to optimise fish outcomes.

In 2023–24, water managers will focus on supporting native fish populations in the Severn, Dumaresq, Macintyre and upper Barwon rivers.

With healthy account balances as of 1 July 2023, the Department of Climate Change, Energy, the Environment and Water (the department) can set aside water for use in future years to support the longer-term resilience of the catchment through drier times.

Aboriginal water management priorities

Water for Country is environmental water use planned by the department and Aboriginal people to achieve shared benefits for the environment and cultural places, values and/ or interests.

Water managers will partner with Aboriginal knowledge holders and organisations to monitor and manage the use of environmental water in the catchment. This work will be centred around, but not limited to, the availability and use of the Pindari Stimulus Flow account.

Initial planning has begun with Aboriginal knowledge holders and organisations to better describe cultural and environmental water requirements of aquatic fauna.

Weather and water forecast

As at early June the El Niño–Southern Oscillation (ENSO¹) outlook is neutral, with an El Niño watch. This means that while the El Niño–Southern Oscillation is currently neutral, there is a 50% chance that an El Niño may develop later in 2023. This is about twice the normal likelihood. El Niño typically brings hot, dry conditions to Australia, often leading to drought and bushfires.

The short-term rainfall outlook is likely to be below median for the Border Rivers which will be enough to maintain the current soil moisture and run-off efficiency in the catchment, with dam levels remaining high.

Water managers have prepared watering plans that consider a range of weather and water availability scenarios. This is known as resource availability scenario planning. The Border Rivers catchment outlook is rated as dry for the 2023–24 water year.

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

Resource availability scenario

Key planned actions for 2023–24

Native fish

Water managers may use water for the environment to support native fish movement, breeding and recruitment outcomes in the Dumaresq River downstream of Glenlyon Dam and in the Severn and Macintyre rivers downstream of Pindari Dam.

If used, the Pindari Stimulus flow would most likely occur in spring as a large fresh event at Ashford. This will benefit native fish breeding, recruitment and dispersal.

Baseflow events provide fish with the opportunity for movement and population mixing.

Vegetation

Providing a further benefit, flows delivered under the connectivity and native fish actions will be managed to maximise benefits to riparian and aquatic vegetation.

Connectivity

If more water becomes available, water managers may use available held water for the environment to provide a low connection flow along the Dumaresq and Macintyre–Barwon system to replenish and refresh pools.

If moderate sized natural events occur, water managers may deliver water for the environment to extend the duration of the event and/or increase the distance this water will reach downstream. If practical, water managers may release held water for the environment to increase the peak flow rate and to inundate higher benches and low anabranches and their connected wetlands.

If larger natural events occur, the use of NSW’s held supplementary and Queensland’s unsupplemented licences can retain a proportion of these flows instream.

Map of proposed annual priority targets in the water resource plan area 2023–24