Philadelphia's waterfront has shifted identity many times since William Penn first stuck his toe in the Delaware, evolving from a pioneer settlement to a bustling port, from an industrial wasteland to a big-box entertainment and retail district.

Now, as Philadelphia wraps up a five-year planning effort, the river is being prepped to take on a new role. A detailed master plan, which will be presented to the public Monday evening, shapes the empty acres along the central Delaware waterfront into the flagship of a 21st-century lifestyle city, with dense neighborhoods of middle-class housing, street-level retail, gracious parks, restored wetlands, and a riverside recreation trail.

The place imagined in the plan bears little resemblance to the celebrated waterfront neighborhoods of Vancouver, British Columbia, and New York's Battery Park City, where a stockade of skyscrapers lines the shore. Philadelphia planners, led by the firms Cooper Robertson and KieranTimberlake, envision something that looks more like a typical Center City block, with a mix of low- and mid-rise buildings, punctuated by the occasional 20-story high-rise.

As the first serious development blueprint for the area since the early '80s, the plan abandons many of the cherished assumptions that have guided Philadelphia's waterfront policies for the last half-century. The plan's shorter skyline is an up-front acknowledgment that the low housing demand in Philadelphia cannot support a continuous wall of urban high-rises.

Penn's Landing, which for so long was the focus of the city's attentions, is also no longer seen as a viable site for a jam-packed mega-development, for much the same reason.

Philadelphia's energy will now go into developing the publicly owned Festival Pier at Spring Garden Street, which is better linked to the city's pedestrian-oriented street grid and transit system, and well-suited for a Piazza at Schmidts-style mixed-use project.

It's not just the vision for the 6.5-mile stretch of waterfront that has evolved in the new plan. So has the strategy for realizing it.

The city no longer harbors any expectation that a vibrant waterfront neighborhood will spring full-blown from the pages of the plan, said Thomas P. Corcoran, president of the Delaware River Waterfront Corp., which commissioned the strategy. Instead, the plan is structured so development can occur piecemeal over 30 years. The gradual pace means only modest public subsidies will be required.

"Our goal is to hit singles and doubles, and not try to hit for the fences like we did in the past with Penn's Landing," Corcoran said.

It is difficult to evaluate the strength of the master plan because the full text will not be available until September, even though Monday's event is billed as the "final presentation." A citizens watchdog group, the Central Delaware Advocacy Group, is still advocating for several changes. But it's unlikely they would affect the plan's overall strategy, which was described during in an informal presentation last week.

One of the biggest stumbling blocks to developing the waterfront has been the massive canyon of Interstate 95, which cuts off Center City from the river. The planning team concluded, however, that the highway is a significant barrier only for Penn's Landing, where the grade drops dramatically from Front Street to the river. They propose to solve the problem by stretching the existing highway cover - between Walnut and Chestnut Streets - over Columbus Boulevard, and then down to the river.

But elsewhere, they insist, pedestrians can get to the waterfront by walking under the elevated portions of the highway.

"Forty-six out of 72 city streets pass under I-95," argued architect James Timberlake. "It's not necessary to cap it."

Because the repeated failures at Penn's Landing have made Philadelphians cynical about the waterfront's prospects, Corcoran said, the plan lays out a detailed implementation strategy. It includes step-by-step instructions for realizing each project, with precise schedules for making infrastructure improvements, auctioning land to private owners, and building public parks.

Based on the planning team's recommendations, the riverfront corporation will focus on the three most-marketable sites first: Festival Pier, the area adjacent to the Penn's Landing boat basin, and the park at Pier 53. It's no coincidence that all three properties are city-owned.

In the next few weeks, Corcoran said, the agency will begin drafting development criteria for the pier and basin sites. He expects those sites would be put out to bid in about two years, and developers would be selected in 2014.

Once a developer is signed up, Corcoran's agency will focus on improvements at Spring Garden, such as a public park, using its own money and government grants. It could take a decade or more to construct the mix of housing, shops, and hotels proposed for Festival Pier.

The phasing was developed specifically for Philadelphia's housing market, explained John Alschuler of the HR&A firm, who served as the planning team's economic consultant. Relative to high-priced, high-demand cities such as New York and San Francisco, Philadelphia has a "slow absorption rate." So, although there is a steady demand for housing here, the market can be easily overwhelmed by a couple of big high-rises, as it was during the condo boom.

"The kind of increment you'll see on the waterfront is 50 units, 100 units," said Alschuler, who is also the economic consultant for New York's High Line project and London's Olympic Village. Philadelphia also is more likely to create a real neighborhood feeling on the waterfront if it sticks with low- and mid-rise housing, rather than being seduced into building a couple of stand-alone skyscrapers, he said.

Although the housing market is slow right now, Alschuler expects things to pick up by the time Philadelphia is ready to put the two waterfront sites on the market. The city's universities and medical centers are expanding rapidly, he said, and their workers will need convenient housing.

Parks also play a key role in the plan to attract residents. The city plans to build or improve 10 parks, situated at half-mile intervals, over the next three years. Each would act as the town green for a mini-neighborhood.

Based on Alschuler's recommendations, the planning team laid out the central waterfront to accommodate about 6,000 units over the next three decades. According to the Philadelphia 2035 plan, released last week, Philadelphia is expected to grow by about 100,000 residents in the same period.

"Philadelphia is becoming a lifestyle city," Alschuler said. "And the waterfront is a powerful amenity."