The cities of Cockburn and Kwinana would merge, the City of Armadale expanded to include the Shire of Serpentine-Jarrahdale and the City of Melville would gain some suburbs but lose others under proposed local government changes.
Local Government Advisory Board chairman Mel Congerton said maps of the affected areas would be released tomorrow and mayors of the relevant councils had been briefed yesterday on three proposals the board intends to recommend for boundary changes.
"The board is quite comfortable that the new proposals reflect a more appropriate balance addressing each… individual proposal," Mr Congerton said.
Some affected mayors have already expressed disappointment.
The three proposals are open for public comment for several weeks, meaning they could be tweaked before final recommendations go to the Local Government Minister next month.
The need to advertise the proposals was the reason behind a delay in the board's timeframe to deliver its final recommendations to the Minister, which was planned for the end of July but will not happen until late August.
Under the proposals Cockburn and Kwinana would merge, with the suburbs of Bibra Lake, North Lake and Leeming transferred to Melville and Hamilton Hill to Fremantle.
Armadale would be expanded to include Serpentine Jarrahadale and Melville would lose the suburbs of Bicton and Palmyra to Fremantle.