Temporary Water Restriction - Northern NSW Murray Darling Basin Amendment No.2
Reason for Decision
Widespread rainfall occurred across the coastal and northern parts of NSW over the period 6-11 February 2020, resulting in some long-awaited inflows. The heaviest rainfall and largest flows are along the NSW coast, although there has been some welcome rain inland too.
Inflows to northern NSW inland regulated river storages have been very small. There are some higher localised flows further downstream in the Namoi valley and parts of the lower Gwydir that are beginning to restart rivers for the first time in many months.
Despite the recent rain across parts of the northern basin, all the major northern inland regulated valleys (except the Gwydir which is in Stage 3 severe), the Barwon-Darling and the Lower Darling remain in Stage 4 critical drought. While some areas are receiving good flows, this has not generated significant inflows into the major rural dams which remain at very low levels.
Keepit Dam on the Namoi has received some inflows but the storage level is still critically low at 4%. Chaffey Dam which supplies Tamworth remains at just over 13% and Split Rock Dam which supplies the towns of Barraba and Manilla is only at 2%. In addition, Burrendong Dam which supplies Dubbo, Wellington, Nyngan and Cobar in the Macquarie Valley is also below 2%. These towns remain on severe water restrictions and ongoing supply from the storages beyond this water year is a major concern. Mungindi at the start of the Barwon River has still not seen any river flows.
In contrast, due to recent significant inflows generated in the Namoi and Peel, regulated river (high security) access licences in the Upper and Lower Namoi and Peel regulated water sources will not be prohibited by this order. This is due to the small volumes accounted for by high security in those systems which is not expected to materially impact on downstream flow targets.
Flows from the recent rains, if protected, are forecast to reach Walgett (100-120 GL by 9/02), Bourke (50-70 GL by 20-27/02), Wilcannia (20-40 GL by 10-20/03) and to also provide minor replenishment to Lake Wetherell with around 10-30 GL by 18-26/03. Protecting these, and any additional flows from further forecast rainfall over the next weeks, will increase the potential for even larger flows to reach the Menindee Lakes, and allow water to move down the lower Darling River to meet critical human needs, particularly now the system upstream has been primed by the current flows.
These restrictions have maximised the inflows into the weir pools at Walgett, Brewarrina and Bourke to secure those towns’ water supplies. Furthermore, the Brewarrina weir pool has been subject to high levels of salinity for many months now - upstream flows have been protected to refresh the remnant pool, which is important both for town water supplies and for the health of the riverine environment.
This is the first opportunity in almost two years where full river connectivity in the northern NSW basin could be achieved. This would result in substantial benefits for human needs along the lower Daring, as wells as fish health and the riverine environment. Achieving these outcomes would be consistent with the recommendations of recent inquiries into water management of the northern basin.
Extending the temporary restriction on northern NSW tributaries of the Murray Darling Basin to the 28 February 2020 will allow flows to be protected for critical needs in Menindee and the lower Darling. It is important to continue to protect inflows into the upstream storages and along the river for town water supplies, basic landholder rights and refuge pools and to achieve system connectivity as far as the Menindee Lakes, and through the lower Darling.
For the period 18 February 2020 to 28 February 2020 river pumping is not permitted by the licence holders listed in Table 1. This will allow replenishment of town water supplies, supply to high priority users, re-filling of instream refuge pools in the local catchment, and bring much needed flows into the Menindee Lakes and Lower Darling systems.
This restriction does not apply to basic landholder rights or domestic, stock and local water utility access in the unregulated river and regulated river systems.
The order provides for responsive management. That is, should a substantial natural unregulated flow event occur, and that flows are in excess of that required for critical needs in the northern tributaries or downstream river systems, the Department can approve the take of water by access licence holders. Rainfall and inflows will be closely monitored during this period to determine if a repeal, amendment or advice to customers allowing access is needed.
|Barwon-Darling Unregulated River Water Source||Unregulated river (A, B and C Classes) access licences|
|Intersecting Streams Unregulated Water Sources||Unregulated river access licence and unregulated river (special additional high flow) access licence|
|NSW Border Rivers Unregulated Water Sources||Unregulated river access licences and unregulated river (special additional high flow) access licence|
|Namoi Unregulated Rivers Water Sources||Unregulated river access licences and unregulated river (special additional high flow) access licence|
|Peel Unregulated River Water Sources||Unregulated river access licences|
|Castlereagh River Unregulated Water Sources||Unregulated river access licences and unregulated river (special additional high flow) access licence|
|Macquarie Bogan Unregulated Water Sources, with the exception of Campbells River Downstream Management Zone, Macquarie River above Bathurst Management Zone, Fish River Water Source – downstream of Lake Oberon to confluence with Macquarie River, Macquarie River between Bathurst and Evans Plains Creek Management Zone|
|Gwydir Unregulated River Water Sources||Unregulated river access licence and unregulated river (special additional high flow) access licence|
|NSW Border Rivers Regulated Water Sources||Regulated river (high security), regulated river (general security), regulated river (general security A and B class) access licences (unless water is ordered and released from a dam by WaterNSW)|
|Gwydir Regulated Water Source||Regulated river (general security) access licences (unless water is ordered and released from a dam by WaterNSW)|
In times of extreme drought, protecting water supply for critical needs is a key priority. Extending the temporary restriction on northern NSW tributaries of the Murray Darling Basin to the 28 February 2020 will allow flows to be protected for critical needs. It is important to continue to protect inflows into storage and along the river for town water supplies, basic landholder rights and refuge pools and to achieve system connectivity as far as the Menindee Lakes, and the lower Darling.
Having a temporary restriction order on irrigator access allows any moderate flows to be protected for critical needs.
The vast bulk of extraction in the northern NSW basin will remain suspended, under this order, to preserve water for town water supplies, domestic and stock needs, and to restart the river system as far downstream as possible. This includes restrictions to floodplain harvesting (under a separate order). As a result of these restrictions, some of the largest flows in many months are entering the Barwon Darling, with critical supplies returned to some towns, basic landholder rights, domestic and stock supplies, and refilling of key refugia along stretches of the river, as was the intent of the initial restriction.
The overarching aim of the extension to this restriction is to ensure that critical needs (town water supply, basic landholder rights, high security and environmental needs) are met by protecting inflows following the extended dry period – both in local river valleys, and downstream in Menindee Lakes and the Lower Darling. Placing a temporary water restriction order on access to natural, unregulated flows by unregulated licence holders and general and high security licence holders is a way to achieve this aim.
Reasons for Decisions
Temporary water restriction – section 324
Section 324 of the Water Management Act 2000 (the Act) allows the Minister or delegate to order that temporary water restrictions within a water source are to have effect for a specified period, if these restrictions are determined to be in the public interest.
Based on the above information, there is a public interest in making an order to restrict take as follows:
- “To cope with a water shortage” - The recent rains across parts of the northern basin, have been isolated and patchy and some town water supplies remain at risk including Mungindi, Tamworth, Dubbo, Cobar, Nyngan, Bathurst, Orange. Storage levels in our major rural dams including Keepit, Chaffey, Split Rock and Burrendong Dams are still low. The Barwon- Darling, Lower Darling and all of the major northern inland regulated valleys remain at Stage 4 (critical) water shortage under the NSW Extreme Events Policy (except the Gwydir which is at Stage 3). Flows from the recent rains are forecast, if protected, to reach Wilcannia along the Barwon-Darling and into the Menindee Lakes and the Lower Darling. With the upstream system now wetted, protection of further inflows is necessary to provide an opportunity to enable flows to reach the Menindee Lakes and the Lower Darling, to meet critical human and environmental water needs. All remaining supplies in the block banks below Menindee Lakes are almost exhausted.
- “Threat to public health and safety” Despite the recent rains, town water supplies remain at low levels across the upper Gwydir, Border Rivers and the Macquarie Valley. Critical human water needs have not been met in the lower Darling for some time. Similarly, many creek systems have not had full replenishment flows to meet domestic and stock needs. It is essential that all inflows are protected for these higher priority critical needs and to improve water quality where replenishment flows have not been received for some time. A particular focus will be protecting flows for critical human needs in the lower Darling
- “Manage water for environmental purposes” Despite the recent rains, low flow conditions persist across parts of the northern NSW Murray-Darling Basin, particularly the Border Rivers and Macquarie valleys, as well as further downstream in Menindee and the lower Darling. Further protection of flows will assist with re-connecting river systems, refuge pools and wetland areas and improving water quality. No substantive flow has reached Menindee Lakes since 2016, only a small volume as part of the Northern Connectivity Flow reached the Lakes in 2018. Macquarie Marshes have received only limited flows.
A/ Executive Director, Water Policy, Planning and Sciences
13 February 2020