Flowing through farmland in the floodplains between Cowwarr and Heyfield, Rainbow Creek is a short but significant waterway in the West Gippsland catchment.
For the past four years, the West Gippsland Catchment Management Authority has been delivering the Thomson and Rainbow Management Plan to keep the Thomson flowing and to nurture the young, fast flowing Rainbow Creek.
Together with landholders, community and other partners, the WGCMA has been weeding, fencing, removing willows and planting native vegetation to strengthen the Rainbow, keep it healthy for local wildlife and communities and protect it from future events.
The Thomson River and Rainbow Creek Waterway Management Plan was developed in collaboration with community and agency representatives during 2019 and 2020. Community members including landholders along the Rainbow Creek and mid Thomson River, as well as representatives from local government, Southern Rural Water and the WGCMA.
The project will seek to address the risk of avulsion (where a waterway creates a new path in times of flood) across the agricultural land between the Thomson River and Rainbow Creek. This will require partnerships with landholders and on ground works to remove willows, treat avulsion ‘hotspots’, plant native vegetation and fence off waterways.
The program of works will see improved waterway health, with benefits for agriculture, the community and the Gippsland Lakes.
The Thomson River and Rainbow Creek waterways provide important bio links between the Victorian High Country and the Gippsland Lakes.
The mid-Thomson River and Rainbow Creek have also been identified as high-risk sites for future avulsion events. Such an event would prove damaging to agricultural businesses on the waterways and pose significant risk to the Gippsland Lakes with the carriage of sediments into Lake Wellington.
The Rainbow Creek was formed in the 1950s after a major flood event, causing significant disruption to the local community and downstream. Without active management of flow at Cowwarr Weir, Rainbow Creek would be the preferred flow path of the Thomson River.
Managed interventions can reduce the likelihood of avulsion and consequent disruption to livelihoods and the environment.