Hydrologic and hydraulic modelling has been undertaken to inform the options assessment, design and operational planning stages for the Locks 8 and 9 project. Modelling will be fundamental to validating project feasibility, through considering designs, outcomes, costs and impacts, prior to commencing the design, submission and approval process.
Frequently asked questions
Learn more about the project through these frequently asked questions and answers.
When will weir pool trials commence at Locks 8 and 9?
There have been ongoing weir pool trials at Locks 7 and 8 over the last five years through a coordinated approach between Victoria and New South Wales.
Current constraints, including the Millewa pump station at Lake Cullulleraine, have prevented weir pool trials at Lock 9. The proposed relocation and replacement of the pump station commenced in June 2022 and is anticipated to be complete prior to higher water periods in late 2022. The replacement and relocation of the pump will enable weir pool manipulation to be implemented at Lock 9. Further details on the Millewa pump station project are available from Lower Murray Water.
How far are we proposing to lower Lock 8 and Lock 9?
Several investigations including third-party socio-economic and infrastructure impact studies have been conducted to inform the operating plan for Locks 8 and 9.
The final operating plan will need to ensure a balance between ecological and socio-economic objectives can be achieved. Consultation is being conducted with identified stakeholders to assess the possible impact of any changes.
Any proposed changes to operation will need to be formally adopted under the provisions of the Murray-Darling Basin Agreement.
What time of year do we propose to lower Lock 8 and Lock 9?
Investigations have been undertaken to determine the optimal operating regime for Locks 8 and 9. Operating principles will be required to allow for a wetting and drying regime providing flexibility to meet the water requirements of neighbouring ecosystems, as well as meeting the needs of downstream users (irrigators, towns and stock and domestic).
The range of considerations involved in future water level management will be documented in a Review of Environmental Factors to be finalised later in 2022.
Will the Fort Courage Boat Ramp be impacted by weir pool lower at Lock 9?
Investigations have been completed to determine third-party socio-economic impacts associated with the proposed lowering of Locks 8 & 9. The information gathered during investigations is being used to identify the level of impact on both pump and non-pump infrastructure, such as boat ramps and pontoons, and to assist in determining what, if any, mitigation measures will be required. The investigations will also determine any impacts to trafficability within the river and commence to flow levels for creeks and anabranches connected to the Lock 8 and 9 weir pools.
What if my pump is impacted by weir pool lowering?
An assessment of all pumps within the reaches of Locks 8 and 9 has been completed and will be used to determine what impact the change to operational water levels may have on pump infrastructure and what, if any, mitigation will be required. The project has and will continue to consult with water users prior to finalising a weir pool operating plan. Consultation will continue throughout the life of the project.
What type of fishway are we proposing to construct on the Frenchmans Creek Inlet Regulator?
Options for the Frenchmans Creek fishway were identified and assessed with preference being for a vertical slot design. Key stakeholders from SA Water, Murray-Darling Basin Authority, NSW Fisheries, Department of Planning and Environment - Environment and Heritage, Department of Primary Industries and other technical experts have been consulted on each option to determine the most suitable fishway design for this location.
A concept design is expected to be finalised by late 2022 to assess the project’s viability. Stakeholders on the project’s Technical Advisory Group and Stakeholder Advisory Group will be consulted on the concept design prior to any decision to move to approvals and construction.
When will the proposed regulators and fishways be constructed and operated?
The project is currently in the design and approvals phase. The project is due to progress works on the Carrs, Cappitts and Bunberoo Creek floodplain to construction once statutory approval requirements have been assessed and validated.
The construction phase is anticipated to commence in the second half of 2022 and will be managed by SA Water.