The hot potato of Alma Plaza is about to get tossed to the Palo Alto City Council, after another round tonight with the Planning and Transportation Commission.

For more than a decade, the city, owners and nearby residents have muddled through a series of proposals for the site. In the 1990s, when the market was a Lucky's store, a proposal surfaced to build an unacceptably large market, more than twice the 20,000-square-foot limit for "neighborhood shopping centers."

Later, when Albertson's purchased the center, years of give and take finally arrived at a reasonable compromise of 29,000 square feet. But that plan ran head-on into a one-two punch: (1) a year-long moratorium for a traffic-and-safety study of the Charleston/Arastradero roads corridor and (2) a corporate crisis within Albertson's that caused it to drop the plan and ultimately close its Palo Alto markets at Alma and Edgewood plazas. Moratorium or no, hindsight indicates Albertson's likely would have dropped the Alma plan.

Then John McNellis of Palo Alto-based McNellis Properties, a specialist in resuscitating troubled shopping centers who represented both Albertson's and Lucky's, purchased the site. But there was a catch: A deed restriction imposed by Albertson's limits any future market there to fewer than 18,000 square feet.

McNellis' alternate vision has now evolved to 39 single-family homes (reduced from 45) plus a medium-sized, 17,300-square-foot market, plus a coffee shop and some commercial space. "Public benefits" include a small park, 14 low-income apartments above the market and a 1,330-square-foot "community room," also upstairs.

McNellis insists restricted access makes the site unsuitable for more retail, citing consultants and the long decline of the old center. But there is evidence the decline was due mostly to Albertson's policy decisions and neglect, in anticipation of approval of a larger center.

The current plan is scheduled to reach the council April 16, with a strong negative recommendation from planning commissioners, who want more retail.

The plan also is opposed by well-organized neighbors, "Friends of Alma Plaza." The Friends have hired their own consultant, who says the site could still be a strong retail center. Hundreds of residents have signed a petition urging "primarily commercial" there. The city planning staff is backing the current plan, citing "substantial public benefits," mainly the 14 low-income apartments.

Yet a key issue is being virtually ignored: the inherent vagueness of the planned community (PC) zone. Alma Plaza is one of a few parcels in the city zoned PC, meaning the city has not established any specific zoning policy or restrictions. It allows a property owner to propose any development plan, and persuade the community of its benefits. The approved project constitutes the zone's conditions.

The city's Comprehensive Plan, which guides but does not restrict development, designates Alma Plaza as neighborhood commercial. With PC zoning, developers naturally propose what will be most profitable, and they sweeten their proposals with "public benefits," which city officials often expand -- a form of legal civic bribery (if the benefit is offered) or civic extortion (if it is required).

In many cases, PC-zone "benefits" have morphed into private elements of the development, inaccessible to the public and with no follow-up or enforcement -- or even memory of what was once required -- by an overloaded planning staff.

Alma Plaza's decay is a good example of why the PC zone must be reformed. The lack of a clearly adopted zoning for the property has led to endless debate, and allows a patient owner to wear down all involved until everyone simply gives up from fatigue.

The council now should either approve the present plan, provide explicit guidelines for what it would take to gain council approval, or simply rezone the entire site "neighborhood commercial" (which allows mixed-use housing) and see what proposals come forth, from McNellis or a new owner. We agree with neighbors and the planning commission that a stronger retail presence is called for on this site, other than the market.

The risk is that the plaza will remain a ghost-town center. But a fixed zone would provide solid footing for a developer to build upon rather than a mushy PC zone defined project by project with outcomes that depend excessively on the developer's negotiating skills.