Architect hired to study linking Center City to waterfront

The firm has not been asked to explore the possibility of burying or removing I-95, as many have advocated, but will focus instead on finding ways to improve the existing connections at key points between Market and South Streets.

The immense chasm created by the highway and Columbus Boulevard - 1,200 feet in places - has long been seen as the reason for the repeated failure of development projects at Penn's Landing and the adjacent waterfront. Waterfront advocates argue that the only way to fix the problem is to undertake a Philadelphia version of Boston's Big Dig, either by submerging and covering the offending section of I-95, or removing it entirely.

While the project initiated Thursday is less than they wanted, the decision to hire a design firm is nevertheless a sign that the Nutter administration remains committed to moving the waterfront project forward. Even in its limited form, the improvements are expected to cost hundreds of millions of dollars, and take years to complete.

After reviewing proposals from four teams, the Delaware River Waterfront Corp. settled on Hargreaves Associates, a firm with a reputation for finding imaginative design solutions to complex infrastructure problems. DRWC officials said they were impressed with Hargreaves' success at overcoming similar highway divides at the Louisville, Ky., and Chattanooga, Tenn., waterfronts.

In Louisville, Hargreaves, which has offices in Cambridge, Mass., and San Francisco, reshaped the land under an elevated highway so that it sloped gently down to the Ohio River. The other big benefit of the massive earthworks project is that it created a visual connection between downtown and the waterfront.

In Philadelphia, the firm will be paid $425,000 to develop a set of conceptual designs that could be refined later into buildable projects. Hargreaves will focus on four strategic points along the waterfront: the existing cap over I-95 between Chestnut and Walnut Streets, the Market Street scissor ramps, the pedestrian bridge at South Street, and the land around the marina basin.

Designing new connections at these spots is just a beginning, acknowledged Marilyn Jordan Taylor, who chairs the DRWC's planning committee, but "we felt it was time to start moving forward with that technical and conceptual work."

Their action comes after nearly a decade of discussion about the central Delaware, one of the least developed of all urban waterfronts in America. It's been two years since the DRWC completed a master plan for the area.

It was that plan that first scotched the idea of getting rid of the '60s-era highway, which cuts off the oldest part of Philadelphia from William Penn's original landing spot. Instead, the plan suggested building a wide, bridge-like structure to ramp down to the water's edge. There is an existing cap on top of I-95, between Chestnut and Walnut Streets, but it stops at Columbus Boulevard - 30 feet above the level of Penn's Landing.

Mary Margaret Jones, the Hargreaves principal who will work on the design, said her team had already begun talking about possible strategies. One option would be to stretch the existing cap over Columbus Boulevard to create a large park. The elevated structure would be brought down gradually to the waterfront level with a series of terraced "rooms."

Whatever solution they propose, it will involve razing the Great Plaza, the amphitheater that was installed at Penn's Landing in the mid-'80s in effort to make the space more usable. The problem, Taylor said, "is that you need 5,000 people to make the space feel activated."

It is a bit ironic that the cap will become the centerpiece of Hargreaves' work. When discussions about improving the Delaware first began, the intent was to move away from Philadelphia's single-minded focus on Penn's Landing, perhaps the most difficult site along the central Delaware.

But Taylor believes it is time to shift the focus back to Penn's Landing, the most public part of the waterfront, she said, and the extended cap has the potential to become Philadelphia's "fifth square." It would be the same size as Rittenhouse Square, about seven acres. There would be space for the development of midrise buildings on either side of the new park.

After the waterfront master plan was released in 2011, the expectation was that the city's first big project would be a mixed-used development on Festival Pier, at Spring Garden Street. Progress on that project has been delayed because of the need to do extensive soil and structural studies, to determine how much shoring would be needed to support building construction. The pier was once occupied by a city incinerator.

The results of that testing is expected in the next four to six weeks.

Contact Inga Saffron at isaffron@phillynews.com, 215-854-2213, or on Twitter @ingasaffron.