A new report released from the Department of Environment, Land, Water and Planning (DELWP) has tipped the two suburbs in Ballarat's south-west to be among the three largest regional growth areas in the state.

Delacombe's population is expected to more than double from 7195 in 2016 to 19,196 by 2036, a 2.7 per cent annual growth figure, the highest in regional Victoria.

Alfredton's population is tipped to climb from 11,852 to 26,437, an annual increase of 2.2 per cent and third in the state behind the Geelong suburb of Grovedale.

Ballarat overall is expected to see its population soar from 107,330 in 2018 to 145,930 by 2036, an annual growth of 1.7 per cent. Geelong is tipped to grow at 2 per cent, while Bendigo should climb by 1.6 per cent.

Committee For Ballarat chief executive Michael Poulton said the figures showed how imperative it was to get planning processes right now.

"Our position continues to be we want to embrace population growth. It is inevitable so let's get together and do this really well," he said.

"Planning should include provision for intra-city connections within Ballarat such as new railway stations, connected buses, trackless trams and intercity connections between regional centres.

DELWP principal demographer, David Sykes said projections were calculated using mathematical models, expert knowledge and trend analysis to estimate future size, distribution and population composition.

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