Located around Renmark, Bookmark Creek is an 8 km anabranch that bypasses Lock 5 and 13 km of the River Murray main channel in South Australia. A significant head difference between the inlet and outlet exists due to the bypass of Lock 5, presenting the unique potential for fast-flowing habitat conditions for a number of large-bodied native fish species; potential which has not been fully realised due to a series of impeding structures along the Creek.
Importantly, 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. This area is also the traditional home of the First Peoples of the River Murray and Mallee region.
Originally a natural creek depression that flowed during periods of high river flows, Bookmark Creek underwent significant changes instigated by European colonisation, which brought with it development of the first Australian irrigation district in the late 1880s. This was followed by construction of Lock 5 in 1927 which following construction, resulted in permanent inundation at the inlet. These changes meant the creek was used as a reservoir to supply irrigation water, then later as an irrigation disposal basin.
The combination of these factors have had adverse impacts on the ecological values of the site and has contributed to environmental degradation of the landscape over time.
Significant investigations and local planning initiatives have been undertaken in the area and through the South Australian Riverland Floodplains Integrated Infrastructure Program (SARFIIP) Master Planning Project, there is now a strategic vision for the entire complex.
Following a holistic ecological and hydrological assessment undertaken with continued stakeholder engagement, possible infrastructure and management solutions have been identified. These have been considered in the context of other opportunities emerging in the region, which forms the Sustaining Riverland Environments Program.
The program of works and measures in the Bookmark Creek and associated wetland complexes aims to:
- replace two dilapidated siphon-pipe structures on Bookmark Creek with new infrastructure that can substantially increase the flow of water down the creek
- incorporate fish friendly infrastructure to reinstate connectivity between Lock 4 and Lock 5 weir pools
- upgrade infrastructure at additional sites to improve their function and integrate their operations with weir pool manipulation (in river and in Bookmark Creek) and future higher flows.
This will enable the following environmental outcomes:
- Improved fast flowing habitat for large bodied native fish.
- Enhanced environmental outcomes from increased hydraulic diversity and connectivity for fish.
- Enhanced social, economic and recreational benefits associated with improved connectivity, amenity and condition of high value wetlands/floodplains.
The Sustaining Riverland Environments Program is a $37.6 million program funded by the Australian Government through the Murray-Darling Basin Authority and delivered by the Government of South Australia through the Department for Environment and Water.