Chowilla Report Card 2020–21

2020-21 Water Summary

C
Water for the environment delivered to wetlands is providing important refuge for birds, fish and frogs in an otherwise dry landscape. However, the health of trees and plants across the site has continued to decline due to the dry conditions over the past 3 years.
Overall
C Vegetation
B Waterbirds
A Fish
B Other

Vegetation

C

Aims

Maintain river red gum, black box, river cooba and lignum populations
Improve abundance and diversity of grass and herb-land, flood dependent understorey and aquatic vegetation

Outcomes

While the target for river red gum condition was met (70%), continuing dry conditions meant river red gum health declined.
Black box, river cooba and lignum across the site are generally in poor condition and declining. Without further watering the decline in health will continue.
Delivery of water for the environment to 5 wetlands improved the health of wetland plants, lignum and trees fringing these wetlands.
66 species of wetland and understorey plants were found at Chowilla, which is 20% more than the previous year.
Regular delivery of water for the environment to wetlands resulted in the highest number of wetland plant species ever recorded. While there was an increase in understorey plant species numbers too, this was due to a shift to more salt tolerant species on a drying floodplain.

Waterbirds

B

Aims

Create conditions for successful breeding of colonial waterbirds
Maintain or improve the diversity, abundance and distribution of key bird species

Outcomes

No colonial waterbird breeding was observed. Although key wetlands were available during waterbird breeding seasons, the broader landscape remained dry. However conditions were met the previous 2 years, therefore the one in 3 year target for colonial waterbirds breeding was met.
The sequential delivery of water for the environment to – Gum Flat, Werta Wert and then Lake Limbra – created habitat for waterbirds from summer through to autumn. 45 waterbirds species were recorded across these wetlands, including thousands of pink-eared ducks and grey teals. Several migratory waders, including sharp-tailed sandpipers and pink-eared ducks, were also observed at Gum Flat.
At Lake Limbra black swans, white-headed stilts and Australian shelducks bred. At Coombool Swamp, which still held water for the environment delivered in the previous year, black swans continued to breed.
Across river red gum and black box sites, the target for the expected number of bush birds species was not met. This is likely due to the declining condition of the trees and understorey plants that provide habitat for bush birds.

Fish

A

Aims

Maintain or increase the diversity and extent of distribution of native fish species
Maintain successful recruitment of small and large bodied native fish

Outcomes

27,866 fish from 14 species, 10 native and 4 non-native, were recorded at Chowilla and the adjacent River Murray. These numbers are similar to the previous year and similarly included large numbers of bony herring. Non-native fish represented less than 4% of fish counted.
Several native fish including bony herring, Australian smelt, unspecked hardyhead and Murray–Darling rainbow fish successfully bred.
Murray cod numbers included a higher proportion of young-of-year fish (considered less than a year old) and improved numbers of fish that have survived to join the adult population.
Golden perch failed to breed for the fourth year in a row. This is likely due to the flows in the River Murray not being high enough to trigger breeding.

Other

B

Aims

Maintain sustainable communities of the eight riparian frog species recorded at Chowilla.
Improve the distribution and abundance of the nationally listed southern bell frog at Chowilla.

Outcomes

6 of the 8 wetland frog species expected for this region were recorded at the wetland sites that held water. Eastern banjo frog, eastern sign bearing froglet, long-thumbed frog, Peron's tree frog, southern bell frog, and the spotted marsh frog were all recorded.
The highest number of frogs was recorded at Werta Wert, with over 300 frogs estimated to be calling on a single survey night.
Southern bell frogs, a vulnerable nationally significant species, were recorded at 4 wetlands. As this species is now scarce in the Lower Murray, this is a positive sign that Chowilla's wetlands are providing conditions for successful breeding.

6.7 GL

water for the environment delivered at this site

6.7 GL

water used at this site

0 GL

flowing back to the river system

Actions

Water for the environment delivered.

Climate conditions

Moderate - Conditions were milder compared to the previous 3 hot, dry years. River flows were around three-quarters of the long-term average.

Works

Are there works at this site?

Works in use this year?

Highlights

First Nations

The First Peoples of the River Murray and Mallee Region undertook Aboriginal Waterways Assessments (AWA) at 6 wetlands. The AWAs are used to assess the cultural values of wetlands and other important sites. They provide a valuable way of furthering Connections to Country and help inform water planning and other management activities.
(Photo: Murraylands and Riverland Landscape Board South Australia)

Community

Friends of Parks members enjoying a tour of the Chowilla floodplain to learn about the benefits of delivering water for the environment.
(Photo: Sandra Smith)

Vegetation

In response to the delivery of water for the environment, nardoo, a culturally significant aquatic plant, blanketed the Monoman Depression wetland.
(Photo: Helga Kieskamp)

Waterbirds

Red-necked avocets were recorded in the hundreds at Lake Limbra. This was one of the wetlands where water for the environment was delivered, with the drawdown of the wetland providing great feeding habitat for a range of waterbirds.
(Photo: Helga Kieskamp)

Fish

Tagging Murray cod and freshwater catfish is helping to better understand how they move through Chowilla's creeks and wetlands. Results from this monitoring will be used inform future flow delivery through the Chowilla anabranch.
(Photo: SARDI)

Past reports for Chowilla Floodplains

Overall

Vegetation

Waterbirds

Fish

Other

2020-21

C

B

A

B

2019-20

C

B

A

B

2018-19

B

C

B

A

2017-18

B

C

A

-

2016-17

B

A

B

2015-16

C

B

A

B

2014-15

C

A

B

2013-14

C

B

A

B

2012-13

C

B

A

C

2011-12

C

A

D

2010-11

B

C

A

2009-10

C

A

B

2008-09

C

D

A

C

2007-08

-

2006-07

-

Show/hide 5 oldest years

Climate conditions

Grades

Dry	Very Wet
Wet	Moderate

A

B

C

D

-

Excellent

Most (75-100%) of ecological objectives have been met

Good

More than half (50-74%) of ecological objectives have been met

Fair

Fewer than half (25-49%) of ecological objectives have been met

Needs attention

Few (0-24%) of ecological objectives have been met

Data not available

Each year, water is released into the environment depending on the climatic conditions. See the outcomes of water over time for a long-term view of how natural and released water affects the health of rivers.

Follow the science and more information

Report cards are a result of the work we and our partners do with scientists across the Basin, including site monitoring as part of The Living Murray program.

The Living Murray is a joint program funded by New South Wales, South Australia, Victoria and the Commonwealth governments.

If you want to know more about our monitoring and the results — read the monitoring reports

Read The Living Murray – Icon site condition report – 10 years of ecological monitoring

Southern Connected Basin Environmental Watering Committee Reports