The seasonal allocation in the Goulburn system is now 50 per cent for high reliability water, which is an increase of 1pc.

The Bullarook system allocation is 11pc HRWS, an increase of 5pc.

Graeme Hannan, G-MW's resource manager, said the increases have come from small contributions from a range of sources up to the end of December.

"For the Goulburn system storage losses were lower than the provision for December," Mr Hannan said.

"On the Murray system inflows were in line with earlier forecasts for December and an increased provision for river losses has been made consistent with the expected higher regulated flows.

"The Bullarook system has benefited from lower than planned storage releases which have translated into a small allocation increase.

However, the benefit from the rainfall on the 1st and 2nd of January is still to be fully assessed and any improvements for water allocations will be confirmed next week."