A review of Melbourne Water aqueducts found that improved water control infrastructure connected to the company’s SCADA system would enhance water delivery efficiency and minimise the OH&S risks associated with gate operation.
Many reservoirs draw their water directly from protected forested catchments, however, Melbourne Water’s Sugarloaf Reservoir is fed by the Maroondah Aqueduct as well as the Yarra River.
The 30 kilometre Maroondah Aqueduct transfers up to 220 ML/d from Maroondah Reservoir to Yering Gorge. The Yering Gorge Pumping Station pumps water from the Yarra River and the Maroondah Aqueduct, up through a rising main and tunnel into the Sugarloaf Reservoir.
Upon leaving the Sugarloaf Reservoir, water is thoroughly treated at the Winneke Water Treatment Plant to World Health Organisation Guidelines, before reaching Melbourne's domestic water supply.
URS, Thiess Services and AWMA were engaged to deliver staged projects including the design, manufacture and installation of automated control infrastructure for Melbourne Water’s Maroondah and Coranderrk aqueducts.
AWMA’s LayFlat Gate was selected as an appropriate gate design to maximise water flow efficiency within the aqueducts as well as maintain a minimum flow level for water redirection into the Yarra Glen and Frogley Filtration Plants.
The LayFlats allow for a clear flow area of more than 5.2m² for the Maroondah aqueduct and 2.6m² for the Coranderrk aqueduct.
Automated control of the LayFlat allows the gate to automatically adjust to maintain a predetermined upstream aqueduct level. This provides the ability to maintain adequate treatment plant supply whilst varying aqueduct flows to maximise water harvesting opportunities at the Yering Gorge Pump Station.
Prior to installation of the LayFlat, the same function was achieved by manual insertion of timber drop boards. This presented OH&S issues and difficulty in achieving a water tight seal. The LayFlats provide a water tight seal allowing up to two weeks supply to the treatment plant during aqueduct shutdowns for maintenance activities.
Justin Renehan of Melbourne Water advised, “Coranderrk LayFlat Gate will shortly work in unison with the penstocks at Badger Weir. Together they will monitor the stream flow after rain events.
“The penstocks will open to allow available harvest to Coranderrk aqueduct and communicate with the LayFlat Gate to automatically raise or lower the gate as the flows dictate. This eliminates the old and inadequate work method of removing drop boards and manually adjusting penstocks. Within our limits we will use these automated systems to capture every rain event!”