Barwon Water's General Manager Water Systems Carl Bicknell said Geelong's storage levels were tipped to reach 80 per cent by the end of the week.
The last time storages were above 80 per cent was February 2002. It is the highest mid-winter level since 1996.
Mr Bicknell said despite relatively dry conditions in Geelong this winter, rain had been falling in the Otways and storages had increased three percentage points in the past week.
So far this month, 113 mm has been recorded at West Barwon Reservoir. The July average is 135.7 mm. At nearby Mt Sabine, more than 263 mm has fallen — well above the monthly average of 182 mm.
"This continues the pattern of good rainfall in our catchments this year. West Barwon has had above, or near average, rainfall each month and Mt Sabine has had above average every month this year," Mr Bicknell said.
Year to date, West Barwon has received 732 mm. The long-term yearly average is 1,143 mm. Mt Sabine is on track to surpass the yearly average of 1,509 mm. Year to date, 1,393 mm has been recorded.
"Currently, the combined total for the Barwon and Moorabool systems is 79.3 per cent. At the same time last year, the total volume was 31 per cent.
"This puts us in a very good position with the remainder of winter and the traditionally productive spring still to come. "The ground is now saturated so every millimetre of rain is producing runoff into the storages," he said.