Chowilla Floodplain and Lindsay-Wallpolla Islands

Chowilla Floodplain - watering events 2016–17

In 2016-17 the Chowilla floodplain was inundated by high natural flows. Approximately 5,600 ha of floodplain and temporary wetlands were inundated and the Chowilla Regulator was tested to the highest level to date (19.84m AHD).

In addition to reinstating connectivity and mobilising carbon and nutrients between the floodplain and River Murray, conditions were conducive for germination and growth of flood-dependent and flood-responsive vegetation.

Monitoring is showing that the vegetation inundated is improving in condition and the floodplain is looking healthier than it has in years through the combination of high flows, environmental water and use of infrastructure over a number of years.

Ecological objectives

There are 3 high-level ecological objectives for the Chowilla Floodplain:

  • maintain high-value wetlands
  • maintain the current area of river red gum forest
  • maintain at least 20% of the original area of black box vegetation.

Underpinning these high-level objectives are 17 specific objectives, which were developed to quantify changes in the condition of the floodplain. These targets are detailed in the Chowilla Floodplain Environmental Water Management Plan.

Image of Werta Wert Wetlands in Chowilla National Park. Photo by Arthur Mostead
Werta Wert Wetlands in Chowilla National Park.

Environmental works

Through The Living Murray program, an environmental regulator has been installed on Chowilla Creek. The Chowilla Creek environmental regulator, and other structures are important in the management of the floodplain. The new structures divert water from the River Murray into Chowilla creek, where the environmental regulator holds it. To protect the habitat of iconic native fish species such as Murray cod and golden perch suitable flow rates are maintained through the river and anabranch creeks when the environmental regulator is in operation. This inundates large areas of the floodplain at more natural frequencies, resulting in simulated high flows and restored health while using less water than in a natural flood. The regulator, along with other structures, benefit about 7,500 ha of the floodplain.

Past watering events

Water Year Volume (GL) Outcomes
2015–16 22 Improved health of near-bank trees and long-lived species including river red gum, black box and coobah, and understorey species including lignum and Moira grass

2014–15

105

First use of water management structures supported floodplain vegetation response, frog breeding and waterbird diversity

2013–14 

4.7

Water pumped to key wetlands to support recovery of vegetation and improve wildlife habitat

2012–13

0.1

Water pumped to Brandy Bottle Wetland to support recovery of vegetation and improve wildlife habitat

2011–12

3

Water pumped to Coombool Swamp to improve health of river red gums, ligum and black box

2010–11

0.14

Water pumped to key wetlands to maintain vegetation and wildlife habitat

2009–10

4.39

Pumped water to key wetlands to prevent health decline in trees and provide drought refuge

Lindsay–Wallpolla–Mulcra Islands - watering events 2016–17

Due to the high natural flows in spring 2016, there was only a small environmental watering (0.46 GL) in autumn 2017 for Sandy Creek at Wallpolla Island, to consolidate the benefits of the spring conditions.

High natural flows supported fish breeding and recruitment, in particular in Lindsay River, Potterwalkagee Creek, Mullaroo Creek and Mulcra Horseshoe and Snake Lagoon.

Ecological objectives

There are 3 high-level ecological objectives for the Lindsay–Wallpolla islands site:

  • increase the diversity, extent and abundance of wetland vegetation
  • increase abundance, diversity and extent of distribution of native fish
  • provide habitat for a range of waterbirds, including migratory species and colonial nesters.

Wallpolla Island following environmental watering in 2010.

Environmental works

Environmental water management structures have been built at the Lindsay–Wallpolla–Mulcra Islands site, as part of The Living Murray program. These structures, including regulators and levee banks, allow available environmental water to be used more efficiently and effectively to simulate natural flow patterns. The works project involved extensive collaboration with the Mallee Catchment Management Authority and local Aboriginal people.

Past watering events

Water Year Volume (GL) Outcomes
2015–16 8.6 Promoted wetland vegetation and temporary habitat for waterbirds, frogs and native fish. Germination and recruitment of aquatic vegetation, red gum recruitment, and feeding opportunities for waterbirds.

2014–15

6.7

Floodplain connectivity, red gum and lignum benefits

2013–14

3.7

Successful first commissioning of water management structures at Mulcra Island. Benefits for river red gums and aquatic vegetation

2012–13

Nil

Not watered due to construction of water management structures but some natural flooding occurred

2011–12

Nil

Not watered due to construction of water management structures but some natural flooding occurred

2010–11

Nil

Not watered, however some natural flooding occurred

2009–10

6

Prevented the decline in health of long lived vegetation, including mature river red gum, black box, and other high priority vegetation, and to provide a drought refuge

* The content of this website is currently being updated to reflect recent amendments to the Basin Plan.