Goulburn-Murray Water (GMW) will deliver more efficient channel dewatering in the future thanks to the installation of a penstock at one of its regulators – a development that also provides water delivery benefits for its customers as it allows for maintenance activities to be undertaken in a timely manner.
Every year during the irrigation off-season GMW dewaters parts of its channel network to allow its Winter Works program to take place. This program delivers crucial maintenance on assets that are usually beneath the waterline and ensures GMW can continue to supply water in an efficient and timely manner.
During this year’s Winter Works, GMW’s Civil and Environmental Services teams in the east and central regions installed a penstock at a regulator on the EGM channel near Dookie which will help with future dewatering efforts. A penstock is a sluice gate that regulates and controls the flow of water.
It was installed so that GMW can trial using a penstock to drain channels to sills without needing to syphon water for days. Sills are raised concrete sections built into the floor of a regulator when the system was modernised.
GMW Operations Manager (East) Luke Dunham said draining channels to the sills can be challenging.
“We need to dewater channels in winter to inspect assets, allow weeds to frost and to undertake maintenance works but large channels have poured up sills which are problematic,” he said.
“On top of that, syphoning water from the channels is labour intensive and does not get all the water out of the pool.
“It also requires staff to check on the syphon pipe every day.
“In some regulators there may be capped pipes we can utilise to drain the pool.
“This however involves staff having to wade into the water and find a small, capped pipe. In a large channel this process can take weeks to drain the pool to be able to find these pipes.”
GMW staff have also previously undertaken large scale pumping and used earthen coffers (a temporary wall made of packed clay) to dewater sections of channels to allow frosting of weeds or maintenance works to take place. This process is labour intensive and less efficient than using the penstock to dewater channels.
During this year’s Winter Works, GMW replaced the need to use four 50mm syphon pipes at a regulator on the EGM channel near Dookie with a 300mm penstock.
Mr Dunham said the penstock will provide a number of benefits for future dewatering efforts.
“It will allow us to dewater channels much more quickly and safely,” he said.
“Instead of staff needing to carry around a lot of equipment and start syphons with pumps that need priming, all they need to do with the penstock is turn a handle.
“It will save us a lot of time by staff not needing to go through all the aspects involved in the syphoning process such as the hours of set up involved for each syphon pipe and the need to check on them daily.
“We’re hoping to install more of these penstocks at other regulators where there are large sills within the next Winter Works period.”
GMW Manager Distribution Services Operations Craig Kellow said it was fantastic to see the penstock in place and the benefits it provides.
“Our Civil and Environmental Services teams in the east and central regions have worked hard to install this penstock, and our Water Delivery Services team in the east has also worked hard to dewater the regulator pool manually," he said.
“The outcome of everyone’s work is that we now have a penstock in place that will not only benefit us in dewatering channels more efficiently and safely, it will also benefit our customers.
“It also means more time for our staff to get onto other maintenance projects during Winter Works, delivering even more improvements to our water delivery network in the irrigation off-season.”
GMW’s Winter Works program takes place every year during the irrigation off-season from May 16 to August 14 when GMW does not have its usual water delivery obligations.