Fate of Riverside South lies with Planning Commission.

It's the City Planning Commission's turn to take on Riverside South, the largest mixed-use development being planned in die city. But it also could be the last chance for the 74-acre project along the Hudson River, because a "no" vote means the end of the line.

The commission, currently made up of 12 members with one vacancy, is scheduled to vote today (Oct. 21) after a public meeting. The land use review clock officially ends on Oct. 26 and there is a slight possibility the vote will be carried over to that date.

A majority of the commissioners will be needed to pass the project onto the City Council. Sources say that while many of the commissioners are in favor of the 8.3 million square-foot project as a meaningful development for the city, the vote will be close because of the general consensus that there are still open issues and some backroom politicking.

The commissioners are appointed one each by the borough presidents and the president of the City Council - Adrew Stein - while the other seven are mayoral appointees with one of the his seats currendy vacant.

There is currently believed to be a number of differing agendas among board members. Brooklyn is mad at Manhattan because of opposition to Brighton-by-the-Sea; the Bronx want $7 million promised in an earlier deal; Queens doesn't want competition for its own Silvercup television studios; and Andrew Stein, after polling Upper West Side residents on his mayoral chances if he opposes the development, is now opposing it.

Meanwhile, affordable housing, the improvement and mitigation of the 72nd Street subway station, and the master plan for the park, particularly its upkeep and layout until and when the elevated Miller Highway is moved, are the subject of ongoing negotiations and discussions between the Riverside Planning Corp. - made up of former opposing community groups and headed by developer Donald J. Trump - and the city.

The sewage capacity of the North River Plant is no longer an issue, and the commissioners are "more comfortable," now that Enviromnental Protection Commissioner Albert F. Appleton has allayed their fears over capacity, a spokesperson said.

According to Rosina K. Abramson, executive director of The Department of City Planning, the problem with the residential project is that it came in "unbalanced," with the only major public amenity being a park.

"What we are trying to do is create a more balanced approach," she said. A "balanced approach," in other words, means more give-backs for the West Side community.

The park needs to be more user friendly, she said, with more open space, and the commissioners are asking for a more detailed plan for the interim park.

"Negotiations have intensified and there has been progress on the park design issue," she said, adding that a series of technical issues concerning the maintenance are outstanding. Trump has agreed to pick up 50 percent of the maintenance already.

The affordable housing issue is one of income category, she said, as the developer has also agreed to allocate 20 percent of the approximately 5,500 apartments, contingent on government subsidies.

The subway hinges on the amount of money the developer is will to give to an overhaul. Borough President Ruth Messinger, who approved the project, was criticized for only extracting $5 million in "matching funds," for the station.

Lastly, the commission needs to protect community interests by timing permits or other development needs to steps taken by Riverside South to comply with any agreement.

"It's going to be close," said one city official who asked not to be identified.