Water plants used by fish inundated during April 2018 connectivity event. Photo: NSW DPI Fisheries and QLD DAF
Olive perchlet sampled from the Dumaresq River. Photo: NSW DPI Fisheries and Queensland Department of Agriculture and Fisheries 2019
The Border Rivers
The Border Rivers region contains diverse and natural environments that support domestic water use, agriculture, tourism and recreation, mining and the cultural values and practice of local Aboriginal Traditional Owners.
The Border Rivers region supports many native fish including threatened species such as the Murray cod, silver perch, southern purple-spotted gudgeon, olive perchlet and freshwater catfish. The Border Rivers native fish population has been assessed as one of the healthiest in the Northern Murray-Darling Basin, particularly for Murray cod and freshwater catfish.
The Border Rivers’ many billabongs and wetlands, when flooded, support nationally and internationally significant waterbirds including the great egret, brolgas, Australian painted snipe, black-necked storks, magpie geese and royal spoonbills.
The Morella Watercourse/Boobera Lagoon/Pungbougal Lagoon complex is a nationally significant wetland, with the Boobera Lagoon considered to be one of the most important Aboriginal places in eastern Australia. Boobera Lagoon is also one of the few permanent waterbodies in the Northern Basin, providing valuable habitat for wildlife during drought.
The lower reaches of the Severn River in Queensland and the Severn River in New South Wales are also significant areas, supporting a large range of native fish and providing refuge pools to these species in time of drought.
For more information, please see Latest water use for the efforts of the Commonwealth Environmental Water Holder in protecting and restoring the Border Rivers region.
Delivery of environmental water to date (October 2022)
Releases from Glenlyon Dam (Dumaresq) April 2019 Photos: Sunwater and the Department of Natural Resources and Environment, Department of the Environment and Energy
A combination of Commonwealth (regulated and unregulated) and New South Wales environmental water has been delivered to the Border Rivers since 2011–12, which has helped to support native fish outcomes, riparian vegetation and river and wetland connectivity.
Following 2016-17, when the Border Rivers region experienced the largest flow events since January 2013 that helped to meet several environmental demands, the catchment experienced low to no flow conditions. These conditions at the start of 2017-18 limited opportunities for native fish recruitment, as well as potentially impacting the survival of young fish.
In spring 2017, environmental water was delivered to the upper Border Rivers (NSW Severn and Dumaresq river systems) to support the survival of young native fish, and promote recruitment in 2017-18 to build population resilience. Commonwealth environmental water was also delivered in autumn 2018 to contribute to the Northern Connectivity Event. This delivery supported the maintenance and conditioning of native fish in the Dumaresq and lower Macintyre river systems by providing increased access to food and habitat.
Bonshaw Weir May 2019. Photo: Department of the Environment and Energy
Dumaresq River at Texas May 2019. Photo: Department of the Environment and Energy
2018-19 in the Border Rivers was characterised by largely dry conditions, higher than average temperatures and below average rainfall. 7,400 ML of Commonwealth environmental water from Glenlyon Dam (Dumaresq) was used in April and May 2019, topping up refuge pools and supporting native fish resilience in the Dumaresq, Macintyre and the Barwon-Darling to past Walgett (the ‘Northern Fish Flow’). The flow provided in-catchment benefits for native fish like Murray cod and freshwater catfish by topping up refuge pools, improving water quality, increasing access to instream habitat, food sources and providing some opportunity to escape from smaller isolated waterholes. The Northern Fish Flow also provided benefits for instream aquatic vegetation in the Dumaresq and Macintyre, particularly important for small-bodied native fish species like olive perchlet and purple-spotted gudgeon.
In 2020-21, water deliveries included 896 ML of Commonwealth general security water from Pindari Dam and 2,000 ML of NSW planned environmental water to support native fish populations in the Barwon-Darling in late 2020 and early 2021 (the Northern Waterhole Top Up).This watering action extended the spatial extent of drought refuge and pool protection in the Border Rivers and the Barwon River.
In the Queensland unregulated part of the catchment, 17,425 ML was left instream in the Dumaresq, Barwon and Macintyre zones and 2,120 ML in the Queensland Severn, contributing to natural flows to boost outcomes for native fish, platypus and other animals and plants as well as connection with the Barwon-Darling.
With wet conditions predicted to continue into 2022-2023, the Commonwealth is unlikely to deliver regulated water in the Border Rivers during this water year. Should opportunities arise to fill gaps or maximise outcomes in combination with natural flows or other forms of water, targeted deliveries may be made to improve native fish outcomes and/or support connection with the Barwon-Darling and other northern tributaries. If drier conditions return, refuge connection and replenishment flows may also be delivered.
What has environmental water achieved in the Border Rivers?
Monitoring and evaluation activities are helping to identify what is working and what is not, with the result considered as part of the planning and decision-making process undertaken by the Commonwealth Environmental Water Office and our state and local delivery partners.
A summary of monitoring in the Border Rivers:
- Environmental water delivered in April and May 2019 as part of the Northern Fish Flow provided base flows to the Dumaresq (downstream of Glenlyon) and Macintyre rivers and partially met base flow requirements at Mungindi (end of system). These flows helped to support conditioning and maintenance of native fish populations in these rivers, by topping up refuge pools and providing access to food and habitat.
- Monitoring by NSW DPI Fisheries and Queensland Department of Agriculture and Fisheries to support the Northern Fish Flow found that there were good numbers of Murray cod in the Dumaresq, Macintyre and Severn, with lots of young-of-year fish. They also recorded small numbers of adult Freshwater catfish. High abundances of small-bodied native fish were found in the Dumaresq including the endangered Olive perchlet and Southern purple-spotted gudgeon. Extremely high amounts of fish food sources (macrophytes and shrimp) were also recorded.
Young Murray cod and golden perch caught in the Dumaresq River after spring 2017 environmental water delivery. Photo: NSW DPI and QLD DAF
Fish and flows monitoring
Fish monitoring in the Border Rivers by NSW DPI Fisheries and QDAF funded by the CEWO from 2015 to the end of 2018 shows the release of water for the environment has improved the native fish community in the Border Rivers. For more information please refer to the Border Rivers monitoring page.
Healthy Murray cod caught in the Severn River as part of the Border Rivers fish and flows monitoring project (May 2018) Photo: NSW DPI Fisheries and QDAF 2019
Fish habitat mapping
The CEWO, in partnership with the Murray-Darling Basin Authority, has funded aquatic habitat mapping of parts of the Border Rivers and downstream Barwon-Darling. In the Border River, mapping has included the Dumaresq River and the Macintyre River, and has identified key habitat features. For more information please refer to: Aquatic habitat mapping to inform water management.
Commonwealth environmental water use is planned, delivered and managed in partnership with a number of individuals and organisations in the Border Rivers region, including:
- Queensland Department of Regional Development, Manufacturing and Water
- Queensland Department of Environment and Science
- Queensland Department of Agriculture and Fisheries
- New South Wales Department of Planning and Environment, Environment and Heritage Group (including National Parks and Wildlife Service)
- New South Wales Department of Planning and Environment, Water Division
- New South Wales Department of Primary Industries – Fisheries
- New South Wales Local Land Services
- NSW Natural Resources Regulator
- Southern Queensland Landscapes
- Border Rivers Food and Fibre
- Local landholders and community members
- Murray-Darling Basin Authority
- Inspector-General of Water Compliance