Lock 3 Reach and Bookmark Creek Complex

About the Master Plans Project

The River Murray is central to communities along the river and has been for many thousands of years. A healthy river is vital for the environment, as well as provision of critical human water needs and the communities and industries that rely on its water.

Currently, there are multiple threats causing ecological decline, within the Lock 3 Reach as well as the broader Bookmark Creek Complex.

The Lock 3 Reach and Bookmark Creek Complex Master Plans Project involved gathering, collating and refining information and ideas on:

  • Current wetland management and river operations
  • Environmental projects and initiatives in development
  • Any new ideas in support of environmental improvements

The information obtained from the project will enable more efficient and effective resource allocation (water for the environment, people and infrastructure) through a clear, prioritised pathway for future investment.

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


Lock 3 Reach

Lock 3 controls 85 km of the River Murray and contains the most diverse range of flow conditions of all the weir pools in the South Australian River Murray. The Lock 3 Reach connects many significant water bodies, including Lake Bonney, Banrock Station and Wachtels Lagoon. It is also the heart of the major townships of Loxton and Barmera, which rely on this stretch of river for critical human water needs, irrigation, industry, recreation and tourism.

The River Murray and Mallee Aboriginal Corporation (RMMAC) holds Native Title over the River Murray within the Lock 3 Reach. The First Peoples’ intimate knowledge and understanding of Country and active participation across all levels is vital to the effective management of this landscape.

There has already been significant infrastructure investment in the Lock 3 Reach to support River Murray environmental outcomes, namely at Pyap Lagoon, Yatco Lagoon and Beldora and Spectacle Lakes wetland complex, as well as recent investment on the Katarapko Floodplain.

The key threats causing ecological decline in the Reach include 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. The Master Plans Project aimed to address the complex combination of ecological and hydrological issues that is unique to the Lock 3 Reach.

Bookmark Creek Complex

Bookmark Creek is an 8 km anabranch, which bypasses 13km of the River Murray channel including Lock 5, straddling the township of Renmark. The broader complex (encompassing areas from the Ral Ral Floodplain to Disher Creek, including wetlands along the creek and surrounding floodplain) has extremely high social and recreational value to the regional community, with an active and well-established local action group supported by industry groups and key stakeholders.

The RMMAC holds Native Title over the River Murray and many floodplain areas within the Lock 4 and Lock 5 Reaches, including Bookmark Creek. The First Peoples intimate knowledge and understanding of Country and active participation across all levels is vital to the effective management of this landscape.

In pre-colonial times, Bookmark Creek was a natural creek depression that flowed during periods of high River flows. The Creek has suffered significant changes instigated by European settlement, which brought with it development of the first Australian irrigation district in the late 1880s. These changes meant the Creek was used as a reservoir to supply irrigation water and later as an irrigation disposal basin. The Creek also saw permanent inundation at the inlet following the construction of Lock 5 in 1927.

Today, as a result of bypassing Lock 5, a significant head difference exists between the inlet and outlet of the Creek. This head difference presents the potential for unique flowing habitat conditions preferred by a number of large bodied native fish species. Currently, however, a series of impeding structures along the Creek prevent it from flowing freely.

The combination of these factors has had adverse impacts on the ecological values of the site and have contributed to significant environmental degradation of the landscape. The lack of an overarching plan for coordinated future strategic investment has led to a loss of opportunity and constraints throughout the 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.

Master Plans Project objective

While significant investigations and local planning initiatives have been developed in the region, prior to the Master Plans Project there was no governing strategic direction for the entire Lock 3 Reach or broader Bookmark Creek Complex.

The objective of the Project was to develop ‘master plans’ for achieving environmental outcomes in the Lock 3 Reach and broader Bookmark Creek Complex through future investment initiatives, in collaboration with community stakeholder groups. The Master Plans Project was informed through consultation and investigations, which identified and explored the feasibility of a suite of options and has made recommendations on a pathway to proceed, demonstrating the value of further investment.

These investments are a combination of infrastructure investments (such as regulating structure upgrades eg. Bookmark Creek) and operational investments (such as management of Lake Bonney), focused on the achievement of environmental outcomes.

Ultimately, 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 finalised master plans are a key foundation in the establishment of the Sustaining Riverland Environments (SRE) Program initiative, which will deliver practical projects to improve river and wetland health, and support native fish in the River Murray.

Master Planning process

The Master Plans Project began in July 2019, an initiative of the Government of South Australia as part of the South Australian Riverland Floodplains Integrated Infrastructure Program (SARFIIP), funded by the Australian Government through the Murray-Darling Basin Authority. The project was completed over two years and is a continuation of the Environmental Pathways Project (EPP) component of SARFIIP. EPP was aimed at ensuring 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.

Traditional River Murray planning approaches have started first with a set of discrete environmental objectives, which focuses the development of options for works and measures to best meet those objectives. The Master Plans Project was delivered using a new approach toward River Murray project planning and prioritisation, facilitating an open community forum to generate and collate ideas with a broad range of potential environmental objectives, rather than a single targeted objective. This resulted in a suite of potential options that can be prioritised for funding under future programs, such as Sustaining Riverland Environments (SRE) Program and the Constraints measures project, based on their alignment with the various objectives of these programs.

Productive and beneficial engagement with the RMMAC Working Group through the Master Plans Project highlighted the need to maintain strong engagement with First Peoples throughout the application of the works and measures, planning of future master planning projects and the next stages of project implementation.

Planning at the site, floodplain and weir pool scale allowed for engagement with a variety of stakeholder groups and generated a variety of potential opportunities and outcomes.

Site option profiles

Working with stakeholders within the Riverland community, a comprehensive list of ideas and initiatives to support environmental outcomes has been compiled, collated and refined to form the foundations of the Lock 3 Reach and Bookmark Creek Master Plans. These ideas and initiatives were summarised into ‘Site Option Profiles’, with some ‘Sites’ consisting of multiple, and in some instances scalable, options.

A total of 19 ‘Site Option Profiles’ have been developed within 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

A total of 5 ‘Site Option Profiles’ within the Bookmark Creek Complex have been developed:

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

Final Master Plans

The Lock 3 Reach and Bookmark Creek Complex Master Plans can be accessed via the links below.

Lock 3 Reach

Bookmark Creek Complex


The South Australian Riverland Floodplains Integrated Infrastructure Program (SARFIIP) is a $155 million investment program funded by the Australian Government through the Murray-Darling Basin Authority and implemented by the Government of South Australia to improve the watering and management of River Murray floodplains in South Australia’s Riverland.