Groups suing Minneapolis over demolition of Peavey Plaza claimed a moral victory Thursday when the downtown Minneapolis site was listed on the National Register of Historic Places.

"This is a very exciting day for us," said Doug Gasek, the new executive director of Preservation Alliance of Minnesota. "It helps us by showing this place is important not just locally, but at a national level."

Gasek's group, along with the Washington, D.C.-based Cultural Landscape Foundation, is suing Minneapolis over its plan to demolish the plaza as part of an in-progress renovation of Orchestra Hall.

Minneapolis City Council Member Gary Schiff, chairman of the council's Zoning and Planning committee, said Thursday the announcement "shouldn't affect the plans at all. It already went through the local review process. This just brings more attention to the space."

The designation, announced Thursday, will be published Jan. 25, according to a statement from the Cultural Landscape Foundation.

Landscape architect M. Paul Friedberg designed Peavey Plaza, which opened in 1975, around the same time as the current Orchestra Hall. It features a sunken plaza, a shallow pool, stepped seating areas and a fountain at the corner of 12th Street and Nicollet Mall.

The National Register action was "not a surprise to us," said Erin Hanafin Berg, field representative of the Preservation Alliance. "We have believed all along that it's a historically and architecturally significant site, but the city wouldn't listen to us," Berg said.

The current plan, approved by the City Council in 2012, would scrap most of Friedberg's original design. The city maintains that a redo is needed to maximize usage and bring the place into compliance with new disability-access laws. The current plan, projected to cost $10 million, was unveiled in October 2011 but has not yet been put in place, although work is underway on the adjoining Orchestra Hall renovation.

Opponents remain determined to save the plaza. "Peavey Plaza's National Register designation is a victory of Paul Friedberg's brilliant design, for Modernist landscape architecture and further undermines the city of Minneapolis' ill-advised demolition plans," Charles A. Birnbaum, Cultural Landscape Foundation founder and president, said in a statement.

Berg said the next step in the pending litigation comes Feb. 5, when a judge is scheduled to hear from both sides. A trial is set for June.

The National Register lists 88,000 historic sites, but only about 2,500 are deemed significant as works of landscape architecture. Thursday's listing is not the same as a landmark designation, which is rarer and harder to achieve. Minnesota has just 29 places designated as landmarks on the National Register.

Staff writer Eric Roper contributed to this report. Claude Peck • 612-673-7977