42mm rainfall in Walhalla, but no issues

(From Michael Leaney, Walhalla)

Thank you to everyone who has made contact expressing concerns over the heavy rain that was due to fall overnight. Walhalla received 42.5mm of rain, and, as you can see, it’s had little impact on Stringers Creek.

Everyone needs to recognise the Stringers Creek, isn’t really a creek, it’s really an urban drain which is capable of handling huge volumes of water. On 9/10 June, over 200mm+ of rain fell in just on 14 hours. The 42.5mm overnight is about 1/5 of this rainfall and as you can see has hardly made an impact on the creek level.

Historically, 100mm rain events are a regular occurrence in Walhalla, happening perhaps once or twice a year, 150mm rain events are not uncommon and occur every 3 or 4 years. 200mm events are relatively rare and take place on a 10 to 20 year cycle.

Walhalla IS a high rainfall area and Stringer Creek has been manipulated over a 150 year period to cope with very high water flows from time to time. On 9/10 June, it must be noted that Stringer Creek never broke it’s banks. The issues that caused damage were a failure of creek walling (much of it 1970s and 1980s ad hoc repairs) and debris (mainly fallen trees) blocking the water channel and causing erosion.

As a consequence. There was no real inundation of property but rather the consequences of flash flooding.

As you will have noted, over the past few days there has been temporary works conducted in the creek to remove debris and shore up damaged areas to prevent further damage. The long term fix is far more complicated and requires detailed design and construction so these problems do not reappear in 20 to 30 years time. Ongoing maintenance is also required too.

We hope that the damage caused to public infrastructure in Walhalla on 9/10 June will be the catalyst for getting a permanent fix and change in the mindset of how Stingers Creek is managed ongoing.

We thank you all for your ongoing interest and valid concerns about rain events in Walhalla and would like to thank Bushfire Recovery Victoria, the West Gippsland Catchment Management Authority, DELWP Gippsland, Regional Roads Victoria and Parks Victoria for taking action to start the process of recovery and we’d especially like to thank Baw Baw Shire Council for stepping up to take on a lead role in agency coordination and community engagement.

There is a long way to go, but we are well and truly out of the starting blocks.