Growing a Healthy Future for the Lower Lakes

Growing a healthy future for the Lower Lakes

Lower Lakes Bioremediation and Revegetation Project | December 2009

Department for Environment and Heritage

www.environment.sa.gov.au The Lower Lakes Bioremediation and Revegetation Project is about getting the local community and government working together to help rehabilitate this wetland of international importance. A project is underway in the Lower Lakes and Coorong region to tackle some of the urgent environmental problems, such as acidification and soil erosion, due to low river flows and unprecedented low lake water levels.

The current situation The Murray-Darling Basin is experiencing the worst drought since records began in 1891. Record low inflows to the River Murray through drought and over-allocation are having a significant social, cultural, economic and environmental impact on the Lower Lakes and Coorong region – a South Australian treasure of international significance. Water levels are dropping, salinity levels are increasing and soils on the drying lakebeds and wetlands are acidifying. This situation is unprecedented. Future predictions indicate that South Australia’s climate will be more variable. As a result, we must find ways to adapt to a future of reduced water availability – and work towards a future of less reliance on the River Murray, particularly for domestic water supply. The South Australian Government is working with local communities and scientists, technical experts and engineers to:

• address immediate drought response issues • plan for worst-case scenarios • develop long-term sustainable solutions.

The risks

Based on water levels at March 2009, over 20,000 hectares of acid sulfate soils were exposed in Lake Alexandrina and Lake Albert resulting in acidic soils forming over much of the dried out lakebeds. This situation is unprecedented.

When potential acid sulfate soils are exposed, a series of chemical reactions occur that generate large quantities of sulfuric acid. In extreme cases, this acidification can cause ecological collapse, killing plants and animals and rendering the water unsuitable for any purpose.

Salinity levels are also increasing throughout the region, and in some areas the salinity levels are now too high for the water to be used for drinking, livestock or even irrigation. If salinity levels continue to rise, freshwater fish and other aquatic animals and plants will struggle to survive.

Photo: Property at Poltalloch, Lake Alexandrina where aerial seeding was carried out in autumn 2009 The project at a glance

The Lower Lakes Bioremediation and Revegetation Project is about getting the local community and government working together to address some of the serious environmental issues this internationally recognised wetland is facing, such as acidification and soil erosion.

Revegetation techniques, like planting shallow-rooted cover crops, can help address the impacts of soil erosion and assist natural bioremediation to remove acid in sediments and water.

The 2-year project has been made possible thanks to $10 million funding from the Australian Government, and support from the South Australian Department for Environment and Heritage.

This funding is in addition to the $200 million that the Australian Government will provide to South Australia to address environmental problems facing the region as part of the South Australian Government’s $610 million Murray Futures program. The program includes developing a long-term plan to secure a healthy, sustainable future for the region.

The Department for Environment and Heritage is leading the project, in partnership with:

• Milang Progress Association

• Goolwa to Wellington Local Action Planning Group

• Coorong District Local Action Planning Committee

• Ngarrindjeri Regional Authority

• Ngarrindjeri Ruwe Contracting

• Murray Darling Basin Natural Resources Management Board

• Rural Solutions SA.

Photo: Results of aerial seeding undertaken on a previously exposed lakebed on Lake Alexandrina Why is this project important? The combined impact of low flows and reduced water quality is affecting the range of plants and animals that can live in the Coorong and Lower Lakes region.

As water levels continue to drop, exposing more soils in the region, soil erosion is also a significant problem. It can expose new acid sulfate soils and remove nutrients from the soil, which are needed by plants.

Planting vegetation over wide areas of exposed soil will help minimise the effects of wind erosion, and could also reduce the risk of acid sulfate soils in the area.

The Bioremediation and Revegetation project aims to address some of these problems by:

• providing ecosystem stability and resilience

• stabilising sand, dust and soil movement

• helping manage acid sulfate soils through bioremediation

• improving biodiversity. Bioremediation and Revegetation Project

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Kms C o Meningie Adelaide o Lake Albert Wellington r o Melaleuca Centre (Orana) n 0 20 g Meningie School Southern Ocean Kms Meningie Wellington Melaleuca Centre (Orana) Meningie School Southern Ocean What does the project involve?

Through the project, a combination of on-ground works are being undertaken to Revegetation Program 2009-2010 improve the region’s environment, including:

• mapping and research to select the best locations, techniques and plants to use for revegetation works

• on-ground revegetation works, including collecting and propagating native seed for local revegetation, planting, crop and weed management

• fencing to protect the lakebed vegetation from stock

• ecological monitoring and reporting

• developing local action plans, best-practice manuals for bioremediation and revegetation and training materials

• holding workshops, information forums and training courses for the local community.

Cultural heritage assessments will also be undertaken by the Traditional Owners, the Ngarrindjeri people.

Local contractors are being employed wherever possible to carry out works such as aerial seeding and fencing.

The local community can get involved in the project in many ways and receive training to build the skills they need to take an active role in improving the region’s environment. Locals getting involved There are many opportunities for the local community to take a leading role in developing the revegetation projects, take part in training workshops and carry out on-ground works.

Many people in the region are already volunteering their time to grow seedlings and other plants for bioremediation and revegetation projects in the region at one of the community nurseries involved in the project. The nurseries are located at Meningie, Milang, Finniss, Clayton Bay, Hindmarsh Island, Narrung and Goolwa.. Over 5,000 plants have already been grown by the nurseries. They are set to propogate around 130,000 plants in the coming months, to be planted in the Lower Lakes in autumn 2010. Eligible landholders may receive funding of up to $6000 per km for lake shore fencing to exclude stock from the lake bed. Expressions of interest are currently being sought from landholders wishing to fence off the lake edge on their property.

The Lakes Hub, located in the main street at Milang, is a great starting point for anyone interested in finding out more about the project and how to get involved.

You can also pick up information on other environmental projects being carried out in the region.

The Lakes Hub is open during normal business hours so drop into the hub at shop 2, 10 Daranda Terrace, Milang, call 8537 0808 or visit www.lakeshub.com.

Photo: Community nursery staff and volunteers at Meningie Orana Nursery

What revegetation work has already taken place?

Trials to find the best types of plants to help bioremediation in the Lower Lakes began at Lake Albert in November 2008. A range of reeds, seedlings and grasses were planted at two sites to find out what might be best to grow in the area.

The results were used to undertake a broader revegetation trial, where 5,000 hectares of exposed lakebeds across the Lower Lakes region were seeded in autumn 2009. Local landholders were contracted to carry out on-ground seeding, and on large scale areas such as the shores of the Lower Lakes and Goolwa Channel, aerial seeding took place. The seed was a mix of cereal rye and puccinellia. These cover crops are well suited to the soils in the Lower Lakes.

Seeding of the exposed lakebed along the Meningie forshore also took place in spring 2009.

Cover crops planted at Tolderol (near Meningie) were also ‘knife rolled’ in spring. This flattens the crop before it has a chance to seed, forming a layer of mulch across the ground. This will help trap moisture in the soil and reduce evaporation.

The Coorong and Lower Lakes Community Eco-Action Project has also carried out a range of revegetation and bioremediation trials, including investigating the health and growth rate of plants in lakebed soils at a number of sites across the Lower Lakes. Trials to find out which plants grow best under different conditions around Lake Albert’s shoreline are also underway, recording natural vegetation and testing the effects of mulching and adding other organic matter to planted seeds. Many local volunteers have been involved in these trials.

The results from all of these trials will feed into the Lower Lakes Bioremediation and Revegetation Project.

What is bioremediation? Essentially bioremediation involves promoting naturally occurring bacteria to return contaminated environments to a healthy state. Some bacteria in the soil can reverse the process of acid sulfate soils forming sulfuric acid. They need iron and organic matter to do this, so making sure these are available is important. Growing plants (revegetation) can create more iron and organic matter, encouraging bioremediation to take place.

What does the revegetation process involve? Revegetation works involve growing seed and tube stock, planting and managing crops and weeds. The process being used in the Lower Lakes is called revegetation layering. Initial cover crops are used to stabilise the soil and provide a natural mulch. The next layer of revegetation is very important, and involves planting selected native species - some two million sedges (plants similar to grasses or rushes) are recommended for target areas. This is followed by planting a more complex range of native species. This process provides flexibility in how the area is rehabilitated. It is also expected that natural regeneration will occur, which will help cover some exposed areas without any intervention.

Photo: Trials at Waltowa Swamp near Meningie where a range of reeds and grasses were planted in November 2009

Our project partners include:

• Milang Progress Association

• Goolwa to Wellington Local Action Planning Group

• Coorong District Local Action Planning Committee

• Ngarrindjeri Regional Authority

• Ngarrindjeri Ruwe Contracting

• Murray Darling Basin Natural Resources Management Board

• Rural Solutions SA.

Further information

Lakes Hub Website: www.lakeshub.com Location: Shop 2, 10 Daranda Terrace, Milang Phone: (08) 8537 0808 Email: [email protected] Fax: (08) 8537 0807

Department for Environment and Heritage Coorong, Lower Lakes and Murray Mouth Projects www.environment.sa.gov.au/cllmm Email: [email protected] Phone: 1800 226 709 (free call during normal business hours) Post: Coorong, Lower Lakes and Murray Mouth Projects Department for Environment and Heritage Reply Paid 1047 ADELAIDE SA 5001

Disclaimer While reasonable efforts have been made to ensure the contents of this publication are factually correct, the Department for Environment and Heritage makes no representations and accepts no responsibility for the accuracy, completeness or fitness for any particular purpose of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of or reliance on the contents of this publication. Reference to any company, product or service in this publication should not be taken as a Departmental endorsement of the company, product or service.

Photo acknowledgements: Community nursery staff and volunteers on the Meningie jetty, Lake Albert in November 2009.