South Australian Riverland Floodplains Integrated Infrastructure Program (SARFIIP)

Master Plans Project

The Lock 3 Reach and Bookmark Creek Complex Master Plans Project gathered, collated and refined information and ideas on:

• current wetland management and river operations
• environmental projects and initiatives in development
• new ideas in support of environmental improvements.

The goal was to enable more efficient and effective resource allocation (water for the environment, people and infrastructure) through a clear, prioritised pathway for future investment.

The project is a continuation of SARFIIP's Environmental Pathways Project, which aimed to ensure that water returned to the environment under the Basin Plan is managed in an efficient and effective manner, improving the ecological health and resilience of the South Australian River Murray, between Locks 1-7. It fed into the Master Plans Project.

• Access the Lock 3 Reach and Bookmark Creek Complex Master Plans.

Lock 3 Reach: The Master Plans Project aimed to address the complex combination of ecological and hydrological issues that is unique to the Lock 3 Reach. The key threats that were causing ecological decline in the Reach included reduced frequency and duration of floodplain inundation, loss of variability in water levels, salinity load, and obstructions to fish passage. However, the extent of environmental benefit that could be achieved in this Reach has been constrained due to salinity risks, operational constraints and legacy social issues from past river management.

• Lock 3 Reach - Master Plan (download PDF)
• Lock 3 Reach - Master Plan (Online map) (for best experience launch in Chrome)

Bookmark Creek Complex: The Master Plans Project presented an important opportunity for future works around Bookmark Creek to result in hydrological connectivity through this region, unlocking a suite of environmental, social and economic benefits and supporting the growth and wellbeing of the community. An 8 km anabranch, the complex bypasses 13 km of the River Murray channel including Lock 5, straddling the township of Renmark. As a result of bypassing Lock 5, there was a significant head difference between the inlet and outlet of Bookmark Creek. This presented the potential for unique flowing habitat conditions preferred by large bodied native fish. However, a series of impeding structures along the Creek prevented it from flowing freely.

• Bookmark Creek Complex - Master Plan (download PDF)
• Bookmark Creek Complex - Master Plan (Online map) (for best experience launch in Chrome)

Site option profiles: Working with stakeholders within the Riverland community, a comprehensive list of ideas and initiatives to support environmental outcomes was compiled and summarised into site option profiles, with some ‘sites’ consisting of multiple, and in some instances scalable, options.

19 site option profiles were developed in the Lock 3 Reach Master Plan:

1. Katarapko Creek
2. Katarapko Island North
3. Clarks Floodplain
4. Rilli Reach
5. Rilli Lagoon
6. Thiele Flat
7. Loxton Riverfront
8. Katarapko Island South
9. Gerard Complex
10. Pyap Complex
11. Beldora and Spectacle Lakes
12. Yatco Lagoon
13. Loveday Mussels
14. Wachtels Lagoon
15. Lake Bonney
16. Loch Luna
17. Banrock Station
18. Overland Corner
19. Weir Pool 3 Reach

5 site option profiles in the Bookmark Creek Complex were developed:

1. Bulyong Island
2. Ral Ral Floodplain (West)
3. Bookmark Creek
4. Goat Island Paringa Paddock
5. Disher Creek.

The outcomes of implementing a program of works within the Lock 3 Reach and Bookmark Creek Complex, following the Master Plan development, are:

• efficient and effective resource allocation (e-water, people, infrastructure) as a result of having a clear, prioritised pathway for future investment
• confidence and increased flexibility in operations through having a detailed understanding of the outcomes of operational scenarios and how these contribute towards environmental outcomes
• enhanced environmental outcomes as a result of increased hydraulic diversity and connectivity, particularly in improving unique fish habitat in the anabranch system
• enhanced social, economic and recreational benefits associated with improved connectivity, amenity and condition of high value wetlands / floodplains throughout the region.

The Master Plans are a key foundation in the establishment of the Sustaining Riverland Environments Program.

News:

• 19 Jul 2022: Options to improve the ecology of the Lock 3 Reach shortlisted for further investigation
• 12 Oct 2021: Have your say on Master Plans for the Lock 3 Reach and Bookmark Creek
• 10 Jun 2021: First Peoples workshop previews Master Plan process for Lock 3, Bookmark Creek, Weir Pool 3

Salinity Management Measures

The Salinity Management Measures project aimed to reduce the amount of salt that enters the Pike Floodplain. It complements the work completed through the Pike Floodplain Restoration Project to protect the wetlands and floodplains.

The first round of works commenced in June 2018 along the Sturt Highway near Paringa and involved installing a series of groundwater pumping wells and monitoring wells.

The second stage of works commenced in August 2019 to install a pipeline that connects the pumping wells together and moves saline groundwater away from the floodplain.

• In total the project constructed ~15 km of new pipeline and 35 wells ~50 m deep on the highland and floodplain.
• This prevents up to 120 tonnes of salt entering the Pike Floodplain each day from groundwater in the highland and around the floodplain and contributes to the long-term management of salinity in the Pike area.

The groundwater wells pump the salty water away from the floodplain to a disposal basin at Noora. Reduced levels of salt help to restore and protect the floodplain environment by improving water quality for native flora and fauna, and for local and downstream irrigators.

Over time we expect to see water quality improve in the Pike River and Mundic Creek waterways due to these works. Any watering event, whether natural or managed comes with the risk of changes in water quality. Watering events to date have shown that managed floodplain inundations are resulting in a temporary increase in salinity both during and after an event. The potential magnitude of any salinity spike is determined and communicated to stakeholders prior to any inundation. Adaptive management is reducing the magnitude and/or duration of salinity spikes during an event. Repeated operation of the regulator to enable floodplain inundation will, over time, reduce the build-up of salt in the soil profile.

Re-snagging

This re-snagging project has begun to rebuild in-stream woody habitat to restore the ecology of the River Murray and support local fish populations.

This project introduced 47 snags along the River Murray. In 2020, 23 new snags were added:

• 13 snags downstream of Lock 3 near Overland Corner
• 10 snags downstream of Lock 4 near Bookpurnong.

In 2019, the pilot project added a total of 24 snags at 2 sites:

• 4 snags at the initial test site downstream of Lock 4 near Bookpurnong
• 20 snags downstream of Lock 3 near Banrock Station wetland.

The project was a complex process requiring the careful selection of tree type, size, shape, position and river location to maximise ecological benefits.

Sourcing the right type of wood can be a barrier to re-snagging. The tree must have been recently felled so that the snag will sink rather than float away. Snag materials were sourced through the Katarapko Floodplain Project which was completed in June 2020. Trees removed for construction works were re-introduced in the form of snags for in-stream habitat. All 47 re-established snags were sourced in this manner.

‘Snags’ are in-stream woody habitat made of tree root masses, trunks or limbs. They naturally form when trees fall into the river following strong winds, flooding or drought. Snags create variation in stream flow required by native fish.

Without snags, there is no natural way to replenish native fish populations.

In the past, the river was de-snagged to aid boat navigation, reduce flood damage and beautify the river. In the 1990s, this practice was abolished as it became clear that snags play an important role in creating riverine habitat.

The historical removal of snags is thought to have greatly contributed to declines in native fish populations, which have reduced by more than 90% across Australia since European colonisation. Many Australian species experience restricted habitats which are reduced to small and highly fragmented populations, leaving them vulnerable to extreme environmental events.

Benefits:

• Additional snags provide more in-stream woody habitat, which supports bigger populations of aquatic life and increases life in the River Murray
• Increased habitat for bacteria, algae, micro-organisms, native fish, invertebrates and crustaceans
• Indirectly support water birds and predatory marsupial populations
  Increased food sources for native fish
• Support native fish breeding by providing additional surfaces for eggs to be attached to
• Protect native fish populations by providing a place of refuge from larger predators
• Provide a food source for larger predators that like to ‘sit and wait’ for their food
• Snags close to each other support a bigger population of native fish which will be more resilient to changing climate conditions
• Snags will help sustain native fish populations into the future for recreational fishing
  

Results:

Monitoring at the introduced snags, located adjacent to Banrock Station, has found a range of different native species using new snags in the same way as natural snags. Native fish have already been observed using the new structures including golden perch, silver perch, unspecked hardyhead, Murray rainbowfish, juvenile Murray cod, bony herring, and Australian smelt.

• Re-snagging guidelines for the Lower River Murray

The Pike Floodplain Project

The environmental program delivered by the Department for Environment and Water included construction of regulators, fishways and blocking banks at the Pike Floodplain to improve the overall health and resilience of this landscape. A short film has been created to share the great results of the program and the benefits to the Pike Floodplain and ecosystem. This is the journey of the South Australian Riverland Floodplains Integrated Infrastructure Program (SARFIIP) and the valuable legacy it will leave behind for future generations.

On-ground completed works include:

• a regulator and fishway at the Deep Creek inlet
• a regulator and fishway on Tanyaca Creek
• a regulator and fishway on the Pike River
• 2 smaller regulators at Snake Creek North and South
• 2 smaller regulators at Mundic Creek North and South
• replacement of culverts and banks to improve fish passage
• new blocking banks
• a groundwater management scheme comprising 26 bores, pumps and underground pipelines.

The improved infrastructure is being operated to manage water for the environment. An extensive ecological monitoring program tracks the condition of the floodplain, vegetation, plants and animals. This information provides data to inform decisions on floodplain watering events and track the improvements over time. For example, we are seeing vegetation such as lignum responding positively to the inundation and can now be seen thriving throughout the floodplain. Flooded lignum provides great habitat for many native species, including the vulnerable southern bell frog, which have been recorded calling at Mundic Creek, Tanyaca Creek, Snake Creek and Pike River.

Expected benefits:

• Prevent up to 120 tonnes of salt entering the Pike floodplain each day
• Improve connectivity between riverine and floodplain habitats
• Localised freshening of groundwater systems
• Watering of native vegetation including red gums, black box and lignum
• Improve soil conditions as floodplain watering events flush out salt
• Increase sustainability of the tree population by being able to support seedlings with more frequent watering
• Increase food resources, such as waterbugs and aquatic plants, for animals such as fish, yabbies and waterbirds
• Increase food resources and habitat for native terrestrial animals such as bush birds, reptiles and bats, through improving the condition of the floodplain woodlands.

The Katarapko Floodplain Project

Improving the health of Katarapko means managing flows into and around it in a more natural water regime. Water flows into the Katarapko-Eckerts Creek system from the River Murray above Lock 4. The creeks then flow through the floodplain, bypassing Lock 4, and eventually flow back out to the River Murray in weir pool 4. Infrastructure has been improved to enable better management of these flows.

Works included removing barriers and constructing fishways so fish downstream of Lock 4 can migrate upstream through Katarapko.

On-ground completed works:

• Construction of major regulators, that are used to control the delivery of environmental water, at the Splash, Sawmill Creek, Piggy Creek and Carpark Lagoons
• Construction of new regulators with fishways within the Katarapko-Eckerts Creek system to support fish movement
• Construction of smaller structures to help hold the water on the floodplain
• Upgraded infrastructure to manage the habitat of the Murray hardyhead listed nationally and internationally as an endangered species
• Removal of barriers to improve native fish passage and flow of water

The improved infrastructure is being operated to manage water flows to the Katarapko Floodplain. Monitoring shows that the environmental regulators are contributing to a range of positive responses, including greater native fish movement and breeding.

Benefits:

• Native fish passage and flows through 38 kilometres of waterways
• Water quality and connectivity with the river channel
• Environmental flow to the Katarapko Island Drainage Basin.
• Improved connectivity between riverine and floodplain habitats
• Localised freshening of groundwater systems
• Watering of native vegetation including red gums, black box and lignum
• Improved soil conditions as floodplain watering events flush out salt
• Increased sustainability of the tree population by being able to support seedlings with more frequent watering
• Increased food resources, such as waterbugs and aquatic plants, for animals such as fish, yabbies and waterbirds
• Increased food resources and habitat for native terrestrial animals such as bush birds, reptiles and bats, through improving the condition of the floodplain woodlands.

An extensive ecological monitoring program is tracking the condition of the floodplain, vegetation, plants and animals. This information will provide data to inform decisions about floodplain watering events and track the improvements over time.