Manhattan Borough President Scott M. Stringer announced yesterday his conditional disapproval of the proposed Riverside Center development on Manhattan's Upper West Side.

The recommendation addresses modifications and authorizations sought by Extell Development for the final phase of "Riverside South," a large-scale development spanning West 59th Street to West 72nd Street, west of West End Avenue, approved in 1992 by the City Planning Commission and City Council.

The proposal includes five mixed-use buildings, 1,800 public parking spaces, an elementary/middle school, 135,000 SF of ground-floor retail, and an automobile showroom and service center.

According to Mr. Stringer's press release, its "redevelopment has the potential to improve existing site conditions, create thousands of new jobs, and provide much needed neighborhood amenities," noting that "Riverside Center is also the last remaining undeveloped or unplanned piece of the Riverside South development, which failed to achieve broad consensus and resulted in detrimental impacts on the community."

"After careful consideration of the proposed actions, the Manhattan Borough President determined that the current Riverside Center proposal requires significant modification and that outstanding unmitigated environmental impacts must be addressed. While development at Riverside Center may be a generally welcomed addition to the community, that development must not overwhelm the surrounding neighborhood," the press release said.

"This is not about no development," Mr. Stringer said, adding "it's about appropriate and responsible development." He did say, however, that the center's development is "desirable to the Upper West Side community."

Mr. Stringer maintained that Extell's proposal "lacks good site planning, creates inactive streetscapes, and obscures access to the proposed open space." He also said that the project "has many environmental impacts that require real mitigations."

In July, Community Board 7 voted overwhelmingly against eight out of eleven proposed actions and expressed a general conclusion that the Riverside Center proposal failed to meet its core principles based on similar issues of concern to the Borough President.

The City Planning Commission and the City Council will hold hearings on the proposal and vote on it.

An article by Dan Rivoli in yesterday's edition of the West Side Spirit that Mr. Stringer's report states that the bad economy makes additional funding by the School Construction Authority unlikely and suggests that Extell should construct a new 150,000-square-foot school by itself rather than just half of it as now proposed.

"During the borough president's review process," the article continued, "Extell agreed to make 20 percent of residential space permanent affordable housing." Extell had also lowered the heights of some of the proposed towers.

Extell spokesperson George Arzt gave Mr. Rizoli a statement on the borough president's decision:

"We are disappointed that the recommendations by Borough President Stringer do not adequately recognize these continuing difficult economic times. The proposed reduction in density, along with the borough president's other recommendations, threaten the economic viability of Riverside Center. This project will bring important and significant benefits to the city and the community, create tens of thousands of construction and permanent jobs and generate new tax revenues for the city and state. We will continue to discuss the project with the borough president as [the public review process proceeds and are hopeful we are able to receive his support."

Christian de Portzamparc is the architect for the project.