Weir pool manipulation

What is a weir pool water level manipulation and why is it necessary?

River regulation through the construction of dams and weirs has affected the River Murray’s natural hydrological variability (changes to water levels and water flow speeds throughout the year) and this has had impacts on the health of the River Murray.

Almost all native plants and animals along the River Murray rely on regular changing water levels to be healthy, diverse and abundant. Locks and weirs have changed the river and connected or disconnected wetlands to a series of pools which rarely change in water level. Unfortunately, the frequency of natural floods such as the one experienced in 2016 is not regular enough to maintain a healthy ecosystem. The system needs variations in water level to remain robust.

One significant opportunity to improve the health and resilience of the River Murray in a highly modified and regulated system is to improve the management of water levels within weir pools. The weir pool manipulation project will do this by raising and lowering weir pool water levels. Our goal is to encourage a return to greater biodiversity and strengthen the web of life we all depend on. This action may help to maintain a higher level of biodiversity through the next drought period.

Weir pool water level manipulation in South Australia will become an increasingly common feature of routine river operations and greater hydrological variability is expected in future years to improve ecological outcomes along the River Murray.

Weir pool manipulation will contribute to meeting the objectives for a healthy River Murray under the River Murray Act 2003 in the recently amended River Murray Act Implementation Strategy 2014.

As part of the South Australian Riverland Integrated Infrastructure Program,weir pool manipulation aims to improve the health of wetlands, floodplains and backwaters along the River Murray in South Australia.

Lead agency

Department of Environment, Water and Natural Resources

Partners

SA Water, Murray-Darling Basin Authority

Funding partners

The South Australian Integrated Infrastructure Program is a $155 million investment program funded by the Australian Government and implemented by the South Australian Government to improve the watering and management of River Murray floodplains in South Australia’s Riverland.