Spring 2022 update for environmental water releases

All Wimmera floods have individual characteristics. This leads to challenges in predictability. Everything from when they occur and how dry or wet a waterway base is at the time, to what influencing factors have evolved in a riverine landscape and the amount of rain and where rain falls.

This October’s Wimmera flood is no different to other historic events when it comes to having its own ‘personality’. Rain-producing weather systems took their time to influence the Wimmera catchment. When they did, through a gradual build-up in wet conditions, they primed the catchment, promoting natural flows in rivers and creeks.

October 2022 vs September 2010 flood peak times

• The nature of this flood has been similar to the September 2010 flood, but considerably slower. The flood this year reached its peak at Glenorchy quicker than 2010, receding in similar fashion. But it then peaked at Drung and Horsham much slower than 2010.
• The slow movement of the flood peak has been hard to predict. Key factors have included:
  • Thick crops holding water back and directing flows into new areas that might have never seen as much water before.
  • Upstream storages releasing water to manage high water levels based on anticipated further rain.

Spring flows

Floods are also nature’s tool in reinvigorating environmental life. This year’s flood means Wimmera CMA can hold back on the next scheduled releases of water for the environment. Based on the ‘boom and bust’ cycle of the Wimmera landscape and when floodwaters have long gone, water for the environment will soon again become essential to maintain river health. It will be a tool in countering the inevitable ‘bust’ when dryer conditions return and waterways, through deteriorating water quality, can no longer sustain this spring’s ‘boom’ in aquatic life.

RECOVERY

Floods influence community life – as much as the broader environment. By nature, the impact of floods can be long-lasting. They generate considerable community anxiety and heartache.

Wimmera CMA is involved with flood recovery and encourages people to get in touch about flood-damage to waterway fencing and public infrastructure such as waterway crossings or bridges, as well as erosion issues.

• Complete online form
• Email wcma@wcma.vic.gov.au
• Phone 03 5382 1544