It's been a dozen years since the city laid down a 12-foot-wide strip of asphalt along the Schuylkill in Center City and called it a park. At the time, officials were unsure whether people would venture to the waterfront, and so the path was opened without any landscaping or amenities.

How things have changed.

Any day now, the Schuylkill River Development Corp. will start formal construction on the fourth installment of the now wildly popular waterfront trail. Called Bartram's Mile, the $6 million addition is the first segment to make the leap across the river and extend the recreation path into the neighborhoods of Southwest Philadelphia. This time, it will be lushly landscaped, with groves of trees, gentle hills, and grassy meadows.

With the opening of Bartram's Mile expected in late fall, the dream of a continuous waterfront path stretching from the city's northwest corner to its southern tip is starting to look like a reality. Though there is still years of work ahead, the progress over the last decade suggests a steady, incremental approach is an effective way to reclaim our once-industrialized waterfronts for the public's enjoyment.

Bartram's Mile also represents another kind of leap. Bringing the park to the underserved Kingsessing neighborhood will demonstrate that waterfront trails aren't for just the city's elites. Surrounded by a tangle of rail lines and the Schuylkill Expressway, Southwest Philadelphia has felt cut off from Center City and the universities. The trail, which stretches from 58th Street to the Gray's Ferry Bridge, will eventually make it possible to bike downtown in under 20 minutes.

The challenge will be to find a way to suture the separate parts of the trail. In addition to the original Center City segment (which includes the boardwalk extension to South Street), the SRDC has completed a crescent-shaped greenway around the edge of the Gray's Ferry peninsula.

To connect the two sides of the Schuylkill, the SRDC is gearing up to construct a $13 million trail bridge between Bartram's Mile and Gray's Ferry. Though that span should be finished by the middle of 2018, the SRDC still has to close a gap on the east side, between South and Gray's Ferry. The stretch from South to Christian is scheduled to start construction this year, but the remaining portion is still up in the air.

Despite the missing link, Bartram's Mile will still be able to function as a usable park.

I visited the site this week with landscape architect Jose Almiñana of Andropogon, the firm overseeing the project. What was striking was how much of the park already exists.

In preparation for construction, Andropogon and the SRDC cleared away the brushy undergrowth and trash from the banks, opening up magnificent views of the Center City skyline. Because so many large trees had self-seeded along the waterfront, including elms, locust and sassafras, Andropogon was able to create instant shade groves with selective pruning.

The firm also saw value in retaining remnants of the waterfront's industrial heritage, by incorporating fragments into the park's design. At one time, this part of the Schuylkill was a belching industrial corridor: National Gypsum produced the raw material for wallboard. National Heat & Power provided storage for fuel oil. The Sunoco oil refinery is still a short distance downriver.

After remediating the soil to remove heavy metals, Andropogon sculpted a series of knolls around the indentations left by National Heat's oil tanks. Surviving concrete foundations will become benches.

Bartram's Mile will have a more pastoral feel than the Center City trail, which had to be squeezed into a narrow strip of land between the river and the CSX freight line. Because the western bank is now owned by a city agency - the Philadelphia Industrial Development Corp. (PIDC) - the SRDC was able to negotiate a hundred-foot setback for the park. Meanwhile, the colonial-era Bartram's Garden, which sits in the middle of the route, will allow its shoreline to be incorporated into the trail.

That doesn't mean industry will disappear entirely from the riverfront. A trash-transfer station is still operating on Botanic Avenue, a route for part of the trail.

Several handsome industrial structures remain, and the PIDC hopes to market them to manufacturers. It also has long-range plans to build mid-rise structures for offices or light manufacturing on cleared sites bordering the trail. For the PIDC, the main benefit of the park is that it creates what its president, John Grady, calls a "campus environment" that will help attract tenants.

Although there is no reason such commercial uses can't coexist with a waterfront trail, let's hope the PIDC sensitively integrates those new industrial buildings into the landscape. It's possible to imagine designs that benefit the park by extending the greenery farther upland. There could also be ground-floor workshops with garage doors that open up to the park, adding to the mix of activities.

From the beginning, the Schuylkill trail was always viewed as a way to attract development, and the SRDC board is composed almost entirely of developer-minded people: builders, land-use attorneys, university presidents, corporate leaders, and city officials. There is only a single "citizen" member on the 24-person board.

As the trail expands to more neighborhoods, shouldn't more residents be represented? How is it possible that no one from the Bicycle Coalition has a seat on the board, given the trail's importance in the city's bike network?

One consequence of the heavy development focus is that the needs of trail users can be overlooked. The Bartram's Mile site was an opportunity to build a wider path and reduce the conflicts between pedestrians and bicyclists that we see elsewhere on the trail.

"A 14-foot path would have been generous and preferable," the coalition's director, Sarah Clarke Stuart, told me. Instead, the SRDC stuck with the same 12-foot-wide standard it established in Center City.

"I don't think you're going to have the same crowds at Bartram's Mile," SRDC president Joseph Syrnick responded.

Of course, that's what they said when the Center City trail opened.