The new design for Peavey Plaza in downtown Minneapolis isn't even public yet, but already there is a ruckus about whether the redo will mar what some regard as one of the great American Modernist plazas.

Two of the three members of the design team, including the original designer, claim they and the public have been cut out of the process. Meanwhile, a group of 40 people, many of them landscape architects, circulated a letter insisting that key original elements of the plaza, such as its fountains and multi-level spaces, be retained.

The public gets a first look at the proposed design at an Oct. 19 open house from 4:30 to 6 p.m. in the Orchestra Hall lobby.

"I think people will be pleasantly surprised when they see the artist's design," said Council President Barbara Johnson, who sits on a panel of officials that have reviewed the plans.

The plaza is a popular gathering spot for groups ranging from patrons of neighboring Orchestra Hall to lunching downtown workers to homeless people.

The redo of the city-owned and -maintained space is intended to accompany the $45 million expansion of Orchestra Hall, but when it will happen depends on how quickly the city and orchestra can raise funding beyond $2 million in state bonding. Cost estimates have ranged from $5 million to $9 million for various designs.

But some of those who have helped shape the design complained that a tight rein has been kept on discussing design alternatives.

"We were told these plans ... were not to be discussed outside the room," said Erin Hanafin Berg, one member of a community advisory group. Also feeling cut out are Paul Friedberg, who designed the 1975 plaza, and Charles A. Birnbaum, a national authority on preserving cultural landscapes. They were to form the project's design team with local firm Oslund and Associates.

In an open letter to city residents released Monday, they said that, although the process started with a transparent public interview of competing designers, "this nationally recognized, well-loved and public face of the city shouldn't be decided on in secrecy by self-serving public interests."

"It appears to me that Orchestra Hall and the city are calling the shots," Birnbaum said when asked which interests he meant. Johnson said the city is acting on behalf of taxpayers who maintain the space and the orchestra wants the revamped plaza to work with its programs.

Those critical of the design process argue that it has set up a false choice between an expensive rehabilitation of the plaza that's faithful to the original, and a less expensive "inspired-by" design that removes signature features, Birnbaum said.

Hanafin Berg, a field representative for the Preservation Alliance of Minnesota, said many preservationists agree that the plaza could be modified to make it more accessible, easier to maintain and to undo any alterations that detract from the original design. Birnbaum he discussed raising the plaza floor with local preservationists.

The 40-person group calling itself Friends of Peavey Plaza sent a letter last week to landscape architect Tom Oslund, urging him to preserve the integrity of the plaza's design, while making necessary modifications for access and programs. But the group said any revamped design must preserve the plaza's fountains, its waterfalls and pools, keep the multi-level design with a variety of spaces, keep period materials, and the character of Friedberg's design. Oslund didn't respond to a Star Tribune inquiry.

"Peavey Plaza is the first of its kind and the model of the American plaza, combining green with structure," Friedberg and Birnbaum wrote. "It has great bone structure that can accommodate a sympathetic revitalization."

The Preservation Alliance and Birnbaum's Cultural Landscape Foundation both have named the deteriorating plaza as an endangered place. A review by a local historic consultant found that the plaza meets criteria for listing to the National Register for Historic Places.

The Minnesota Orchestra didn't respond to a request for its position on the matter.