The Windsor chapter of the Council of Canadians says the water will be carried in a convoy Thursday through a commuter tunnel to a rally outside Detroit City Hall.
Council national chair Maude Barlow says she will ask U.S. President Barack Obama to declare a state of emergency in Detroit.
The water issue gained national attention last month after activists appealed to the United Nations for assistance.
On Monday, the utility suspended shutoffs for 15 days to educate customers on how to make payment plans.
It has said nearly $90 million was owed on past due accounts.