Decline in water ecosystem health highlights water storage concerns

A report released late last year by Landscapes Hills and Fleurieu highlighted declining trends in populations of fish and macro-invertebrates, which are useful indicators of ecosystem health. Monitoring at 35 sites across the region showed flows as fair or poor in terms of their ecological value.

Landscapes Hills and Fleurieu Team Leader Water Resources Paul Wainwright explained how our landscapes are getting drier, and dams are holding water and not passing on low flows to the environments that need them across the Mount Lofty Ranges.

“Low-flows are regular, naturally occurring, small flow or ‘run-off’ events. They are a vital part of the annual water flow pattern in a catchment and provide life-sustaining water to ecosystems that cannot survive prolonged dry-spells, with many plant and animal species throughout the Mount Lofty Ranges relying on them.

“These low-flows are impeded until dams fill and spill, delaying water flows until later in the season and resulting in parts of the catchments not flowing for as long or as often as they once did. This change to flow patterns is a major contributor to declining catchment health.

“Without these low-flows we are seeing that many of our water-dependent ecosystems in seasonally flowing streams are in poor condition,” he said.

However, there are some positive things happening. In the Eastern Mount Lofty Ranges, some landholders have been having a positive impact by participating in the federal and state government funded ‘Flows for the Future’ program, in which special low-flow devices are incorporated into a dam system to provide low-flows for the environment.

“It’s great when neighbours are working together so that the flows can move through our landscapes and support ecosystem health along the way.”

“In the Western Mount Lofty Ranges, landholders have also participated in a low-flows program and trials, but it has not been possible to install devices throughout catchments and at the scale required to deliver ‘low flows’ and make a big difference for the ecosystem health.”

So what can landholders do to help?

Landscapes Hills and Fleurieu is urging landholders to do what they can to restore low-flows and contribute to the health of our local ecosystems, and their water team is on-hand to help with information and advice.

“It can be as simple as opening a trickle pipe or setting up a siphon to enable some flow to pass down the catchment. This is more important for those dams which rarely fill and spill. In most cases land managers will still have ample water stored for farm-use, while also having a positive impact to support the ongoing health of the catchment they live and work in.

“Those who are holding in dams for primarily aesthetic purposes should also consider their need to retain the same volume of water, and think about releasing some water back into the catchment,” said Mr Wainwright.

To find out more about low flows and how LHF is working to monitor and preserve water-dependent ecosystems, visit our webpage.

For advice on implementing on-farm efficiencies to preserve low-flows on your property call Landscapes Hills and Fleurieu to speak with their water team on 8391 7500.