Toorale Water Infrastructure Project

The area around the junction of the Warrego and Darling rivers is part of Country for the Kurnu-Baakandji Aboriginal People. Toorale has extensive evidence of Aboriginal occupation and activity, including over 500 known Aboriginal sites. Artefacts recorded during 2018 have been dated at over 50,000 years old.

Toorale is associated with significant water management and engineering achievements, including the Boera Dam and Floodwaters Scheme constructed by Sir Samuel McCaughey around 1892. This scheme was one of the most successful and large 19th century civil engineering and water management constructions known to be undertaken by a private individual in New South Wales.

The Warrego and Darling rivers and their floodplains on Toorale provide habitat for a diverse variety of wildlife and plants, including threatened species. When inundated with water, the wetlands along the floodplain spring to life, supporting an abundance of native fish, frogs and waterbirds, including pelicans, brolgas and the endangered Australasian bittern. The lush lignum that has established on the western floodplain provides some of the best habitat for waterbird breeding in the northern Basin. 

Studies have also highlighted the importance of the Warrego River for many of our native fish species. For example, the Warrego River is a significant source of golden perch to the Barwon-Darling system.

The Warrego River can also be particularly important for the Darling River and its dependent communities in years when inflows from other rivers are critically low.

More information on the natural values of Toorale can be found at Commonwealth Environmental Water Office: Looking after Toorale's wildlife and plants.

Extensive ecological monitoring has been undertaken at Toorale. Annual monitoring results are available for the Warrego River and floodplain and the Darling River in annual reports at Commonwealth Environmental Water Office publications and resources.

Monitoring such as this will improve knowledge to inform decisions about relative environmental demands on Toorale and the Darling River to help balance water use.

The Australian Government’s purchase of 25,498 megalitres (ML) of Toorale water entitlements, as transferred to the Commonwealth Environmental Water Holder, comprised:

• 17,826 ML in the Warrego River
• 7,672 ML in the Darling River

The available amount of water that can be used under licence varies from year-to-year according to rainfall, inflows and catchment conditions.

A summary of how CEWO has used its Toorale water licences since 2008 can be found at History – Northern Unregulated Rivers (Intersecting Streams and Barwon-Darling).

In addition to the water returned through the purchase of licences, the regulating structures on Toorale are now managed to pass more of the total Warrego River flow to the Darling River than has been the case in the past.

Toorale has extensive historic infrastructure that was initially built to regulate water across the property for agricultural purposes. This includes water storage dams along the Warrego River that have altered the natural flow patterns. At the time the NSW Government purchased Toorale, the main in-channel storages, starting from the upstream end of the Warrego River, were Boera Dam, Booka Dam, Homestead Dam and Peebles Dam.

Management of flows on and through Toorale is currently constrained by the capacity of pipes at each dam. Movement of native fish between the Warrego and Darling rivers is also affected by these dams, as they currently do not have fish passages on them.

When the flow down the Warrego River is larger than the capacity of pipes in Boera Dam, some water will spill onto the western floodplain. During larger flows, a portion of this water can return from the western floodplain to either the Warrego River or the Darling River. Similarly, if flows are larger than the capacity of the pipes at Peebles Dam at the bottom end of the Warrego River, water can back up and flow into Ross Billabong rather than down the Darling River.

When Toorale was purchased, the NSW and Australian governments agreed to 'demolish, remove, modify or decommission water infrastructure (on Toorale) to improve water flows for environmental purposes'. The Toorale Water Infrastructure Project is being undertaken to achieve this.

Such modifications to the infrastructure will give greater flexibility to share water between Toorale and the Darling River depending on relative needs, thus improving water flows for environmental and other purposes.

The Project aims to ensure that the important values of Toorale are maintained or enhanced, while achieving greater flexibility to pass more water to the Darling River in certain circumstances.

The Project objectives include:

• increase the maximum flow rate than can be delivered to the Darling River
• retain the capacity to divert flows from Boera Dam to the Western Floodplain
• maintain or improve the ecological values and processes for the Warrego and Darling rivers and connected floodplains
• improve fish passage connectivity between the Warrego and Darling Rivers
• minimise impacts to Aboriginal cultural heritage and support the recognition and maintenance of Aboriginal cultural values
• consider social and stakeholder values in the development of options, including adjacent and downstream stock and domestic water access
• minimise impacts to public road access and park operations
• consider recreational and aesthetic values.

The Project will be done in 2 phases:

Phase 1 – Removal of Peebles Dam (complete as of October 2019)

• Peebles Dam is the most southern dam on Toorale.
• The project removed a section of the Peebles dam bank across the Warrego River to enable flows to pass unimpeded to the Darling River.
• More information on Phase 1 can be found on the Project’s review of environment factors webpage.

Phase 2 – Modifications to Boera and Homestead dams (complete as at July 2022)

• Boera Dam will have gated culverts installed. The gates can be operated to either pass flow downstream in the Warrego River or out to the western floodplain, or a combination of both. The new structure will increase the capacity to pass flows down the Warrego from around 600 ML/day to potentially 1650 ML/day.
• Homestead Dam will be modified to pass additional flow downstream by a ‘fill and spill’ arrangement. These structures will not require any active operation to pass inflows.
• Homestead Dam was breached, so it was repaired as part of the project.
• Fishways to allow fish passage will be constructed at the 2 dams being modified so that fish can migrate upstream and downstream along the Warrego River (and into the Darling River). 

Information on the current process for managing the Commonwealth environmental water holdings at Toorale can be found at Commonwealth Environmental Water Office: Portfolio Management Plan – Northern Unregulated Rivers, 2019–20.

The new structures will allow for greater flexibility to meet the water needs of the environment and, in certain circumstances, downstream communities.  The proposed operating rules will prioritise flows to the Darling River when conditions are critically dry, while supporting floodplain values during higher sustained flows in the Warrego River or when the Darling River is flowing well.  

The new fishways will be operated to support fish movement between the Warrego and Darling Rivers during all flows.

The new structures and rules will be subject to approval from relevant government agencies.

The Project has engaged the Aboriginal community (represented by the Toorale Joint Management Committee), local landholders, downstream water users and representatives from local, state and Australian government departments. The proposal has been adjusted several times in response to issues raised and information provided.

Phase 1 of the project, the removal of Peebles Dam, commenced in early October as planned. It was completed ahead of schedule, on 29 October 2019. See time lapse footage of the dam removal below.

The environmental assessment was on public exhibition in January and February 2020 and a number of submissions were received. Construction works commenced in 2021 and were completed in July 2022. Following community consultation in 2021, an Operation and Maintenance Plan (OMP) was developed. The OMP provides a framework for the operation and maintenance of water infrastructure on Toorale National Park and State Conservation Area.

The Toorale water management infrastructure operating and maintenance plan (OMP) provides a framework for the operation and maintenance of water infrastructure on Toorale National Park and State Conservation Area (Toorale).

Management of river flows through Toorale aims to balance the needs and values of local environmental assets and the downstream riverine environment, while minimising impacts to other park and water users.

The OMP addresses relevant statutory and planning matters to ensure that operation and maintenance of the structures is compliant with all of these instruments. It was approved by Department of Planning and Environment – Water (DPE Water) in June 2022.

The OMP describes how the regulating structures will be operated to prioritise environmental assets across a range of river flow scenarios and antecedent conditions. It outlines the management of environmental and other risks, the circumstances when either the Darling River or Warrego floodplain may be prioritised, and guides decisions before, during and post flow events. It does not prescribe the management of individual events, which will be informed by the context and conditions in which the event occurs and in accordance with Annual Environmental Watering Plans prepared in consultation with an Environmental Water Advisory Group (EWAG).

The OMP adopts an adaptive management approach to give flexibility for a range of river flow scenarios and to be responsive to flow and ecological observations (including emerging risks and/or realised benefits) during an event.

The operation of structures on Toorale will be reviewed annually and following significant flow events, informed by monitoring and experience gained from each event and improved modelling and other inputs over time. Stakeholders will also have an opportunity to provide input into these reviews, primarily through the EWAG.

This OMP may be updated at any time to comply with the regulatory framework that is in place, with the approval of DPE Water.

A Fishway Management Plan is currently being developed and will be added to the OMP following testing and calibration of flows through the new structure at Boera by Department of Primary Industries – Fisheries (Fisheries).

To download the plan, go to Toorale water management infrastructure operating and maintenance plan.

Stakeholders are notified of the public exhibition of key documents and any community consultations. However, you can contact the project team at any time.

If you’d like to be added to the mailing list for possible site visits and/or updates, please email the project team.

Water management at Toorale must conform to the NSW Non-Urban Water Metering Policy.

However, there are currently no practical technologies to meter flow to the western floodplain as it is prohibitively wide. Given this, an alternative flow measurement method has been approved by Department of Planning and Environment – Water.

The method, developed by independent consultants, uses a water balance model to calculate an estimate of flows to the western floodplain, eastern bywash and through Boera Dam regulator. An 'App' and new TUFLOW hydraulic model of the catchment were created for this purpose. The Boera Dam level gauge forms the primary data input.

The accuracy of the alternate method was verified by back-calculating the dam inflow and comparing this to the estimated inflow from upstream gauges. The method and App comply with the requirements of the Australian Standard 4747 for meters for non-urban water supply.

This system is setup to be continuously updated and improved in accuracy over time, as more flow data is collected. The outputs from the approved method will be uploaded to this website on a weekly basis.

Boera Dam flow diversion 2022–23

Water was actively diverted to Toorale's western floodplain during a flow event on 2 February 2023 and concluded on 20 April 2023. Adopting the approved flow measuring method for Approval 85CA751696, 221.8 ML flowed from Boera Dam to the western floodplain. This was accounted for against the appropriate Commonwealth environmental water licences and reported to WaterNSW.

Note: Flows to the Western Floodplain commence when the Boera Dam water level reaches 2.26 m (104.85 AHD) on the Boera Dam gauge 423008.