The federal government has pledged up to $50 million to help build a sprawling park on Montreal's West Island, a project that's intended to help quell the effects of flooding and create more green space.

Prime Minister Justin Trudeau and Montreal Mayor Valérie Plante announced the funding for the park in Pierrefonds-Roxboro on Wednesday.

"This is one of the areas most vulnerable to spring thaws and floods in Montreal," a news release from the Prime Minister's Office said.

The funds come from $2 billion the government set aside in 2017 to help communities withstand damage caused by the climate crisis and extreme weather events.

"We are thrilled the federal government has confirmed it will partner with us on this project," Plante said. "It shows that the government understands efforts have to be made quickly and efficiently to be resilient in the face of climate change."

Plante announced plans for the park in June.

It would be Montreal's largest park, spanning 3,000 hectares — four times the size of Mount Royal — and would include 1,600 new hectares of protected area.

However, a group of developers looking to build homes in the middle of the newly announced park in the West Island recently sent the city a legal notice.

They say the administration, along with Pierrefonds–Roxboro borough Mayor Jim Beis, have acted in bad faith, and they want to be reimbursed for the investments they've made over 14 years. They had planned to develop a 360-hectare stretch of land in western Pierrefonds into a new neighbourhood.