Bowenville Reserve & Loudon Weir, Dalby

Monday, 6 March 2023

We had a roll up of thirty-three (33) for this event (35 for lunch – including 2 guests).

I was very impressed with the guided tour by Greg Ringwood (Senior Scientist – Murray Darling Basin Authority) & I learnt a lot – Several things I learnt or at least had clarified are listed below –

  • Greg spoke in Vertical Metres when talking about fishways etc. – I had never heard of this form of measurement before.
  • Construction of fishways in river systems costs in the order of 1.5 million dollars per vertical metre.
  • Fish can move upstream through fishways at any time providing there is sufficient water on the downstream side of the weir.
  • But fish can only move downstream from the upstream side of the weir when water is flowing over the spillway of the weir.
  • Water velocity is the cause of most flood damage & not the height/volume of the water.
  • So, the logic of providing fish habitat (snags etc.) in rivers & other water courses is sound & has several benefits including it reduces water velocity (in flood times) & provides safe homes for our native fish.
  • Clearing of vegetation on riverbanks right up to the waters edge is not good practice either as it can cause erosion of riverbanks & sludge entering the waterways during flood periods.
  • Conversely, to commence clearing a metre or more back from the water’s edge will foster vegetation growth, reduce/prevent bank erosion, & eliminate sludge entering the water way during flood times – A good example of where this is working successfully is Myall Creek in Dalby.
  • Fencing off access to riverbanks & providing watering points for cattle to drink is another good way to reduce/prevent bank erosion.
  • Many landholders with direct access to the Condamine River have successfully applied this practice. 
  • There was a lot of interest from our members with respect to how Scientists were able to sample types & numbers of fish residing in an area of a river & count & tag as required – Greg advised that they use a process of Electro- Fishing where the fish are stunned, float to the surface,  tested & tagged etc,  & released to swim away – Tags cost $5 each.

To sum up, from my perspective this was a very interesting & educational event in tune with the tone of the times (environmental conversation & management) – I thoroughly enjoyed the day.

Following lunch, members birthdays falling in March were acknowledged & celebrated in our usual manner Viz. Damian Carroll, Warwick Dingle & Andy Yates.

Special thanks to all who contributed to making this another safe & enjoyable event for all attendees, including Peter Taylor for organising this event; Michael Bourke assisted by Russell Mauch & Denis McCarthy for looking after our finances & name badges; Peter Thompson for ensuring we were all safe while entering & exiting the coach at all stops; Warwick Dingle for ensuring we were all accounted for before the coach departed again after each stop; Ron Lewis & Lindsay Reis for accommodating our hydration needs; Bob Whittaker supported by Denis McCarthy for their roles as first aid officers; Greg Ringwood for his very interesting & educational guided tour; Fraser from Dalby Council for letting us in & out of the Loudon Weir site; Jan Neal for once again making our much appreciated birthday cake; Cassandra & team at the Russell Tavern for our great lunch; Mark Rowland & Tom McMahon for looking after the loading & unloading of the coach; &, last but not least our driver Nick Peters for setting up for morning tea at Bowenville Reserve (while we were busy listening to Greg’s presentation), & also for transporting us to & from Loudon Weir safely.