Flows for the Future
There are more than 420 sites in the Eastern Mount Lofty Ranges (EMLR) where Flows for the Future solutions have been adopted by landholders to allow low flows to continue downstream.
Flows for the Future (F4F) is a globally innovative program that works collaboratively with landholders across the Eastern Mount Lofty Ranges (EMLR), which includes the Eastern Mount Lofty Ranges and Marne Saunders Prescribed Water Resources Areas, to restore critical environmental flows to counteract a decline in catchment health, which has been detrimental to both communities and the environment.
Dams and watercourse diversions have created barriers to flow in the EMLR by changing the timing and volume of flows. This has compromised natural ecological breeding and regeneration cycles, resulting in an overall decline in catchment health.
F4F provides outcomes for local catchments in the form of stream connectivity, improved ecological health and restoration of riparian habitat diversity, working with landholders to determine the best options for their property.
So far, F4F have worked with more than 1,070 landholders and stakeholder bodies, with landholders at more than 420 sites voluntarily committing to enabling flows to pass barriers on their property in perpetuity and momentum is increasing. With more than 8,000 dams in the EMLR, F4F leads the way in community collaboration and education, enabling communities to achieve significant environmental outcomes in a challenging environment with ever changing dynamics.
Why we need to return low flows
The EMLR is a major contributor to South Australia’s economy, generating $440 million in agricultural production each year. It is also of great importance to the Traditional Owners of the region (Ngadjuri, Kaurna, Peramangk and Ngarrindjeri), whose spiritual, social, cultural and economic practices come from the lands and waters, which brings life and links people and Culture to Country and all living things.
In short, catchment health is vital for river-dependent ecosystems, communities, First Nations, industry, agriculture and tourism. Despite their importance, many watercourses in the EMLR are in poor condition with some parts going without flowing water for longer periods than ever before.
With more than 8,000 dams in the EMLR, Flows for the Future is working to improve the health, resilience and long-term viability of high priority catchments, including the Angas River, Bremer River, Finniss River and Marne River Prescribed Water Resources Area catchments.
The Flows for the Future program is delivered under the Basin Plan and is jointly funded by the Australian Government and the Government of South Australia.
What is a catchment?
When rain falls, the water collects in an area of land which is often bound by hills. The water flows across the landscape, into the soil and streams, eventually feeding a river.How much water ultimately feeds streams and rivers depends on various factors including rainfall, soil moisture and topography.Catchments are complex. When something happens in one part of the catchment, it can have a significant impact on other parts.There are 16 surface water catchments in the EMLR Prescribed Water Resource Area.
What are low flows?
Rainfall is naturally captured in catchment areas travelling downstream in creeks, streams and rivers, supporting all living things as it goes. The natural movement of water has been disrupted by the construction of more than 8000 dams across the EMLR, disrupting the timing and volume of flow provided to the environment.
Low flows are naturally occurring, regular, small flow events that are a vital part of the annual water flow pattern of a catchment.
These days, low flows are impeded until dams fill and spill, delaying water flows until later in the season. This change to flow patterns is a major driver of declining catchment health.
Many water dependent ecosystems in seasonally flowing streams are in poor condition with parts of the catchments not flowing for as long or as often as they once did.
Catchment dams generally fill during medium and high flow events. Low flow devices only pass ‘low flows’, i.e. flows up to a specific ‘threshold flow rate’. During medium and large events the majority of flow goes into the dam while the small proportion below the threshold flow rate is passed. Low flows are only passed when a dam is receiving flow or when there is flow past a watercourse diversion.
Why are low flows important?
The Flows for the Future program will ensure that there is an environmentally sustainable level of water usage and that the creeks and waterways leading to the River Murray and Lower Lakes are able to flow in accordance with the Murray Darling Basin Plan.
Allowing natural patterns of low flows to reach waterways throughout the year also supports the patterns and cycles of native fish, animals and plants which have evolved over thousands of years. Low flows provide and maintain aquatic refuges, support the life cycle of water dependent plants and animals and allow survival throughout the drier summer months.
Fish communities are now struggling and in decline due to altered flow patterns that favour introduced fish species. The Southern Pygmy Perch (Nannoperca australis) and River Blackfish (Gadopsis marmoratus) are now endangered. By restoring low flows, native fish will be able to move to spawning environments and juvenile fish will have a greater chance of surviving to adulthood, helping native fish populations to recover.
Passing low flows (allowing low flows to continue downstream uninhibited) will result in short and long-term environmental responses including:
- longer periods of flow
- a freshening of water pools and reduction in stagnant water
- maintenance of permanent pools
- recolonisation of water-dependent plants
- improvement in the diversity of bugs which in turn assists in nutrient cycling
- help to control pest species such as mosquitoes
- improved stability of water courses.
Returning low flows also helps maintain water quality in backwaters, wetlands and floodplains by flushing salt and pollutants that accumulate during dry periods.
Why do we need to pass low flows?
Securing low flows is one of the important policies being delivered as part of implementation of the EMLR Water Allocation Plan. EMLR water allocations have been issued on the understanding that a program to secure low flows is implemented to improve catchment health and support primary production for years to come.
What are the low flow device options?
Installing a device allows low flows (at or below the calculated threshold flow rate) to pass dams and watercourse diversions while medium and high-flows continue to fill the dam or be extracted from watercourse diversions as per usual. Flows for the Future primarily uses low flow gravity devices or siphons to achieve this.
Gravity low flow device
The preferred option for restoring environmental flows is the gravity low flow device, due to its long-term functionality, low maintenance requirements and minimal visual impact on the landscape. Gravity low flow devices are passive in nature and have an in-flow driven ability to deliver the timing and volume of flows, reflective of each natural flow event.
While gravity low flow devices have been the consistently preferred method for increasing flows, the device’s design has evolved over time due to landholder input, onsite learnings, and the utilisation of more readily available materials. Individual devices are also customised to suit specific site requirements.
Siphon
As gravity low flow devices are not suitable for all sites, landholder input has also enabled the development of a number of tailored solutions, to ensure all landholders have options for restoring environmental flows. One such option is the manual siphon release and schedule system, which relies on landholders’ full involvement and contribution to achieve success.
The manual siphon release and schedule system involves the individual landholder manually turning the siphon on and off according to a historic schedule that mimics environmental low flow timing. While this option doesn’t provide environmental releases reflective of real-time natural flow events, the flow schedule still provides critical environmental flow returns.
Dam removal
Dam removal is another option to reinstate flows and redefine the natural watercourse at suitable locations. This is the environmentally preferred option but is limited to landholders who no longer rely on their dam for water use.
Maintenance
If you have a low flow gravity device installed on your property, check out our new maintenance guide. This step-by-step manual illustrates how to clean a typical device to ensure optimal function.
How does a gravity low flow device work?
Based on community feedback the program is taking a strategic approach to site selection to achieve the best outcome for resources invested.
Some dam and watercourse diversions have more influence on the pattern of flow than others – these are ‘priority sites’ and are the most efficient places to pass low-flows.
If your property has been identified as a priority site, one of our field officers will contact you to discuss options available and funding.
Since the landscape, infrastructure and flow rates are unique at every property, there is no ‘one size fits all’ option to passing low flows. Each device is tailored to the priority dam, or watercourse diversion, in collaboration with landholders.
Contact us
Email: F4F@sa.gov.au
Phone: (08) 8391 2109
The program has received positive feedback from landholders who have installed low-flow devices, detailing the outcomes to the environment including:
- Creeks and waterways are flowing at times of year when they would normally be dry
- Improved condition and increased quantity of vegetation along waterways
- Increased presence of animals in waterways
Hear participating landholders talk about how they are living and working with low flow devices on their dams.
What we have achieved in the first 2 years
Howard Vineyard, Adelaide Hills
Kyara Vineyard, Keyneton
Skye Crawford, growing carob trees in the Bugle Ranges
F4F Newsletter
More information on Flows for the Future can be found in the newsletters below:
Related information
- Eastern Mount Lofty Ranges – reviewing the need to restore flows: a summary of the science and analysis of how catchment heath has been impacted by surface water and groundwater resources such as dams.
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