Why did you do it? –
- After the Thomson River avulsed into Rainbow Creek in 1952, cutting farms in half, the new 15km channel continued to undergo channel migration and deepening, further impacting on farming land and release of sediments to the Gippsland Lakes.
- In 1979 over 300 concrete block groyne structures were built along Rainbow Creek to mitigate lateral migration. An investment of over $6M in today’s market.
What did you do? –
- In 2023 these groynes were assessed by engineers and geomorphologists to determine their stability and effectiveness in proving long-term stability to the system.
What have you learned? –
- The structures have been effective in mitigating gross meander migration and the rate of channel adjustment. In many cases, the river has completely “healed itself” around them. They remain highly effective 45 years later.
Why does it matter? –
- The long-term success of these structures is a great example of how large reach scale management intervention, based on pro-active investment is more effective in managing wholescale system issues over the long-term than small-scale site-based remediation.
Author and contributor information in the form of a short biography (up to 150 words total)
- David Stork is a waterways officer for the West Gippsland Catchment Management Authority. Over the past 15 years, he has specialised in water resource management, river change process management, and structural works.
- Stuart Cleven - Drawing on a combined background of drainage design, geomorphology, and waterway restoration engineering, Stuart has been involved in waterway management and developing waterway restoration projects in Australia for over 22 years.
- Marina Tozer - Marnina is an environmental engineer who specialises in the interactions between hydrology, hydraulics, sediment transport processes, and fluvial geomorphology.