Waterway managers invest significant resources into works aimed at improving waterway condition, yet very few assessments of the impact and effectiveness of these interventions are completed. This lack of data limits the capacity of our industry to apply adaptive management, and restricts our ability to clearly demonstrate the outcomes and value of these investments.

In 2017/18, the first 10 year post-work monitoring data has been collected within Melbourne Water’s Capital Works Monitoring Program. The Program was established in 2006 as the ‘gold’ standard of condition change monitoring following investment in river health improvement projects. Sites are assessed within a before-after-control-impact (BACI) design using macroinvertebrate sampling and components of the Victorian Government’s Index of Stream Condition (ISC) and Works Monitoring Method at 1, 3, 6 and 10 years post-work intervals.

The data collected to date demonstrates measurable changes in condition resulting from intervention works over 3, 6 and 10 year timeframes. The results show that different types of interventions express varying rates of condition change over time, and that pre-intervention condition can greatly influence the rate of change at a site.

This initial data gathered from the Capital Works Monitoring provides a valuable resource to inform adaptive management and advance work practices. Importantly, it provides evidence to support a common assumption applied by waterway managers; that waterway intervention works result in an improvement in waterway condition. As more sites are assessed 10 years post works, we will continue to validate the evidence behind these assumptions.