Wetland report gives insight
An investigation into several iconic Wimmera wetlands has provided important insights into how they respond to climate and landscape changes.
Computer modelling for Natimuk Lake, Lake Wallace and St Mary's Lake shows that drier seasonal conditions on average in recent years and less run-off from paddocks around these lakes due to a shift from grazing to cropping, is resulting in less inflows. The report indicates this is likely to continue in the future.
Natimuk Lake is part of the Natimuk-Douglas saline wetland system and along with St Mary's Lake, they are nationally significant wetlands due to their environmental values. Lake Wallace also supports a diverse range of flora and fauna. The lakes are also important to the local community and are key recreational and tourism destinations for the region.
Hydrological experts used computer modelling to demonstrate changes over time, using information from the community to ensure the models reflected historical conditions. Findings support anecdotal reports that the wetlands don't hold water as often as they used to and the same amount of rainfall doesn't lead to flow volumes that used to take place.
Natimuk local Keith Haustofer says the investigation helped the community understand changes in water levels at their lake.
"We all want to see water in the lake as often as possible in Natimuk Lake and it was really useful through this investigation to see the effects of features in the catchment like drains and culverts on volumes reaching the lake during wet conditions. Based on this report, we can now look at ways to maximise these volumes whilst ensuring there are no negative impacts upstream."
Wimmera CMA chief executive David Brennan said project partners appreciated the support from communities to complete the investigation.
"Thanks to the detailed information provided by the community on historic lake levels we can trust the model results as they replicate what's happened in the past. It's fantastic that we can tap into such a wealth of local knowledge."
Mr Brennan said although the report indicated the lakes would experience reduced catchment runoff into the future, there would still be times when they would contain high volumes of water.
"It's great to see lots of water in Lake Wallace at the moment and we hope that sooner rather than later that we will get higher rainfall and see Natimuk Lake and St Mary's Lake and many other Wimmera wetlands nice and full again, providing a multitude of social and environmental benefits for our region."
Water Technology completed the investigation as part of Wimmera Catchment Management Authority's Wimmera Waterway Strategy 2014-2022. The project was funded through the Victorian Government's Water for Victoria program and supported by Parks Victoria.
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