The Minneapolis City Council has signed off on a vision for a 48-acre tract along the Mississippi River, one of the city’s biggest redevelopment projects in recent history.

The council unanimously on Friday approved the concept plan for the former Upper Harbor Terminal, an industrial zone in north Minneapolis now home to decaying silos and domes. The project would include an amphitheater, hundreds of housing units, new park space, retail and possibly a hotel.

During the roll call vote, opponents of the redevelopment shouted: “And the people? No!”

Then they stood and turned their backs to the council members. They rolled out a banner that read, “The people have spoken, you’ve turned your backs” and “The Mississippi River is sacred.”

They stood for a couple of minutes as the council continued its meeting and then quietly exited the chambers.

Before the vote, council members acknowledged concern over the project, which some believe will lead to gentrification in the surrounding North Side neighborhoods. They vowed to put the community in the forefront while working on the details of the plan.

“There’s a lot of good work still ahead and it’s really just getting started,” said Council Member Phillipe Cunningham, who represents the ward that includes the Upper Harbor Terminal.

Along with the approval of the plan, the council also directed the city to request $2 million from the Legislature for the design of the amphitheater, which could cost up to $49 million and hold 10,000 concertgoers.

Throughout the year, the city, the development team — United Properties, Thor Cos. and First Avenue Productions — and a committee that will include North Side residents will flesh out the different components of the development. A more specific plan is expected next year.

Construction for the redevelopment would start in 2021 or 2022. The first phase of development is estimated to cost $200 million in public and private money.