Premier Jay Weatherill is taking South Australia's fight for more water for the River Murray to Melbourne.
He is meeting with high-profile environmental campaigners on Tuesday including marathon swimmer Tammy van Wisse, the premier said in a statement.
Ms van Wisse, who spent three-and-a-half months swimming the length of the Murray in 2001, says the river is an Australian icon that supports many communities and industries.
"But if the river's sick, everyone suffers," Ms van Wisse said in a statement on Tuesday.
"The Fight for the Murray campaign is seeking more water for the Murray River, as scientific analysis indicates that the current plan to return 2750 gigalitres of water is not enough to return the system to a sustainable level of health," she said.
Mr Weatherill said two million tonnes of salt need to be flushed out of the mouth each year to keep the system healthy – that's more than enough salt to fill the MCG.
Mr Weatherill will also meet Victorian Arron Wood, the 2007 Prime Minister's Environmentalist of the Year and one of the first river 'champions', as well as Environment Victoria chief Kelly O'Shanassy while he is in Melbourne on Tuesday.