Floodplain harvesting is a form of water take that diverts water that either falls as rain or breaks out of the river bank during floods. The water is diverted into private dams using levee banks. It has been an unmeasured form of free water collection, believed to have increased since 1994 by almost two and a half times.
Floodplain Harvesting has attributed to dehydrated floodplains, wetlands, less resilient rivers and depleted aquifers. It has contributed to the rapid decline in size and health of the Ramsar listed Macquarie Marshes, and has been identified in several reports as a key contributor to the mass fish kills in the Lower Darling in 2019.
The NSW Government have been touting that by licencing the controversial practice, they are bringing water take back in line with the Cap Limit on extraction set in 1994, and returning some critically important flood flows to the ailing river systems of the west.
However the Macquarie-Wambool will be missing out on seeing any water returned to the valley, as the NSW Government – keeping true to their form of prioritising irrigation over everyone else – have somehow increased the Cap Limit to allow floodplain harvesting to remain at current levels.
It is bewildering that the Government can wave a magic wand and claim less water is being taken now than in 1994, when we can see the wetlands, rivers and fish dying in front of our eyes.
The NSW Government has legal responsibilities under the Ramsar Convention, Migratory Bird Agreements, the NSW Water Management Act 2000, the Commonwealth Water Act 2007 and the Murray Darling Basin Plan to ensure the resilience of wetlands, prioritise ecosystem health, and ensure water is available for basic landholder rights including Native Title rights to water.
It is not apparent that the NSW Government are acting in line with their legal requirements when it comes to water management, especially floodplain harvesting.
The Ramsar listed Macquarie Marshes needs flood water.
As the volume of water taken through floodplain harvesting has been growing, the size and resilience of the Marshes has been rapidly reducing.
Unregulated floods are critical for sustaining this ecosystem of national and international importance.
The Australian Government notified the Ramsar Secretariat in 2010 of a “likely change in ecological character of the Macquarie Marshes Ramsar site”, stating a range of reasons based on scientific evidence, including changes in the flow regime; change in the extent and condition of the wetland vegetation communities in the southern part of the Macquarie Marshes Nature Reserve; change in extent and condition of wetland vegetation communities in the northern section of the Macquarie Marshes Nature Reserve; changes in the ecological character of the Wilgara wetland and; changes in colonial waterbird breeding.
Keeping the connection is important
The Macquarie-Wambool River has provided 21% of flows to the Barwon Darling-Baaka Rivers over the long term. Unique in the Northern Basin, The Macquarie-Wambool, Castlereagh and Bogan Rivers are winter and spring fed systems, and provide flows to the Barwon Darling-Baaka when other monsoon fed systems don’t.
Records show that the Macquarie-Wambool connected to the Barwon (at a depth in the Lower Macquarie of at least 50cm) 9 years in 11 before Burrendong dam was built. Development of the valley means connection occurs 5 years in 11 now (as of 2017). Connections between major rivers represent important links for the movement of fish, transfer of energy, riverine biodiversity and providing a diverse aquatic habitat.
It seems clear that the NSW Government is acting against its own laws by not applying the priority of use and cultural requirements in the Water Management Act 2000 when it comes to floodplain harvesting licencing and rules in the Macquarie-Wambool Valley.