Sustainability Report 2006/07Environmental flows
A need to increase water storage capacity in Maroondah Reservoir to capture potential spring rain resulted in a staged transfer of water to Sugarloaf Reservoir via the Watts River and the Yarra River, rather than via the Maroondah Aqueduct.
Although this involved additional pumping at Yering Gorge, the staged release of water into the rivers mimicked natural environmental flows, consistent with the 2005 Environmental Flows study. As well as being a much needed addition of water to the system, this provided a valuable opportunity to collect water quality and streamflow data showing how the river behaves under these flows.
This year we completed four new streamflow management plans for the Plenty River, and for the Yarra tributaries Stringybark Creek, Olinda Creek, and Steels, Pauls and Dixons Creeks. These plans seek to balance environmental, social and economic demands on waterways. We have now completed six of the eight plans required by 2010, as set out in the Operating Charter.
The Victorian Government reduced environmental flows in the Yarra River and Thomson River by 10,000 million litres a year. This is a temporary measure brought about by extreme drought and record low inflows to reservoirs.
The Environmental Emergency Contingency Plan now includes an annual review of the impact on the rivers’ environmental health. We undertook additional monitoring of Yarra River habitat and water quality, and this data will be used to assess the impact of low flows on river health.
With Southern Rural Water, we reviewed bulk water entitlements and environmental flows for the Maribyrnong River to more accurately reflect low flow situations. Under the proposed regime, environmental flows will be released occasionally to reflect natural flushing events, rather than a constant flow that depletes Southern Rural Water’s reserves.
River diverters faced their toughest year in 2007/08, with diversions banned from nine waterways and another two on restrictions. Very serious conditions have led to an increased number of compliance issues, with formal warnings issued and prosecutions underway. A strawberry farmer in Cockatoo was successfully prosecuted by Melbourne Water for stealing water from Cockatoo Creek, and fined $5000.
Our new Customer Charter for Diversion Services sets out the rights and obligations for diversion customers and Melbourne Water, and specifies the relevant standards and conditions of service to be met relating to diversion licensing activities. The charter was approved by the Essential Services Commission and came into effect in March.
Melbourne Water and the Department of Sustainability and Environment are trialling an innovative streamflow management plan tender process. Under this process, farmers submit a tender price they would be willing to receive in return for surrendering all or part of their water allocation or agreeing to be managed to new (higher) environmental flow rules.