For decades, Philadelphians heard barely a word about serious planning for the Delaware waterfront. Then Mayor Nutter took office and promised to transform the city's big river. Now it seems we never stop hearing about waterfront planning.

The agency that oversees Penn's Landing held another major event last week to present its latest ideas for the failed entertainment area between Market and South Streets, but you could be forgiven for wondering what was new. All the rituals - peppy speeches, colorful renderings, free pretzels - were the same. So was the plan.

The presentation - held, as usual, in the Festival Pier tent - was billed by the Delaware River Waterfront Corp. as an interim report from its newest consultant, Hargreaves Associates. Six months ago, the firm's San Francisco office was hired, at a cost of $425,000, to refine the proposals for Penn's Landing that had been enshrined in the 2011 Central Delaware master plan. With an experienced designer like Hargreaves on board, we were told, the city was finally getting down to the nitty-gritty of designing a project that would reunite Center City with its stranded waterfront.

So it was a surprise to see that Hargreaves' "design" is really just more planning-think, much of it a rehash of the ground plowed two years ago in the master plan, a joint effort by Cooper Robertson, Kieran Timberlake, and Olin.

Sure, Hargreaves' proposals contain a few fresh nuggets, like suggestions for a modern Tuileries Garden on the I-95 cap and a squiggly, Gehry-esque pedestrian bridge at South Street. But given that the basic outlines for those particular projects were already laid out in the master plan, Hargreaves' contribution amounts to little more than fancy icing on an existing cake. Even their renderings look fuzzier and less developed than those that accompanied the master plan.

That mammoth planning document capped a long public discussion that began in 2003, during the Street administration, and marked a real turning point in Philadelphia's approach to the Delaware waterfront. By clarifying the possibilities for the 6.5-mile-long Central Delaware, the master plan put an end to any lingering fantasies of turning the river's edge into a parade of high-rise towers, on the order of Manhattan's Battery Park City.

What the plan offered instead was a realistic road map for development. It called for midrise housing instead of skyscrapers, generous public spaces, and a traditional street grid, along with a rough timeline for completing each phase.

Sadly, the plan put the kibosh on the dream of burying I-95 and stretching the city grid down to the waterfront. But as compensation, the master planners came up with an alternative: Extend the cap that now covers I-95 between Chestnut and Walnut Streets to the water's edge with an angled platform that would make it easier to walk to the river.

It was Hargreaves' job to explain how such a complex engineering feat could be accomplished.

How would the existing roof over the interstate (which is now partly sunken) make the leap over Columbus Boulevard? Once that roof is extended, will the new structure be an elevated platform that hovers many feet above the water? Or, could it be designed so the structure slopes gradually down to the lapping banks of the river? How much would construction of this giant concrete platform cost? And what strategies could the city use to pay for the sloped park?

Not one of those questions was answered last week.

Instead, Hargreaves principal Mary Margaret Jones spent much of her time describing how the cap could be landscaped as a series of "outdoor rooms," a phrase used so much in landscape architecture these days that it has become a cliche.

There were other baffling elements in the Hargreaves presentation.

For starters, Hargreaves deleted the housing that had been targeted for the Chart House pier site, near the foot of South Street. The renderings show the space as a dull, flat park. Jones says the pier would be used for a concert venue once Festival Pier at Spring Garden Street is developed as housing.

But that decision sets off a series of unfortunate changes. To provide easy parking for concertgoers at the pier venue, the designers had to eliminate the housing that was proposed for the surface lot across the street, on Columbus Boulevard. Great: more vaguely programmed, occasionally used, open space at Penn's Landing.

As it is, the sloping park between Walnut and Chestnut is quite large, almost 10 acres - three times bigger than Rittenhouse Square. In the Hargreaves version, a 2,500-seat amphitheater would be embedded into the slope, with grassy terraces. That makes sense as a concert venue. So, why add another one at the pier just two blocks away? What the waterfront needs now is more permanent residents.

The pier and the land facing the boat basin have always been considered the most desirable real estate at Penn's Landing because of the seamless, at-grade connection at Spruce Street to Society Hill. The people who live in the housing around the boat basin are seen as an advance guard that would help establish the new waterfront neighborhood. But if the city operates a concert venue on the Chart House pier, who will want to live next door?

When Hargreaves was selected in April, the choice generated a great deal of excitement in Philadelphia. The firm has a reputation for clever solutions to difficult waterfront conditions. I've always admired its work in Louisville, Ky., where they shaved off riverbank under an elevated highway to create a visual connection with the city's downtown. Perhaps they will come up with something just as innovative for their final presentation in January.

But time is running out. Nutter, who is the first mayor to take the waterfront seriously, has less than two years left in office. His successor is unlikely to show much love for his signature project. Unless funding is secured and contracts signed soon, the next mayor will be able to ignore the waterfront. And a decade of hope and effort will be dashed.