Backers of a plan to hasten development along the Delaware River by building a trail with pocket parks and other attractions along the South Philadelphia waterfront are closing in on the land they need for the project.

The Delaware River Waterfront Corp. has acquired a section of riverside property from builders K4 Associates and is close to a deal with local developer Bart Blatstein for the final land to build the 0.7-mile bike and walking trail, said Tom Corcoran, president of the nonprofit.

The parcels are contiguous 100-foot waterside slivers of larger sites their owners are mostly prohibited from developing because of proximity to the river, Corcoran said. The DWRC already owns land on either side of the properties.

"We're landscaping their front yard," he said. "It will improve the property values of all the private owners and mean that they can develop more."

The trail is part of a plan to help renew an area dominated by box stores, warehouses, and strip bars. It would start near Washington Avenue and wind south along the waterfront to a terminus near a Walmart-anchored shopping center.

It would be the biggest piece yet of a larger project, the planned 3.3-mile Delaware River Trail extending north to Fishtown. A roughly two-block section between Spring Garden Street and SugarHouse was completed in 2013 by the DRWC.

The trail project joins other public amenities nationwide that have stoked private development.

In New York, construction has followed the High Line elevated park that snakes through Manhattan. In California, plans to revitalize the concrete-lined Los Angeles River have ignited investment along that waterway.

In Philadelphia, the DRWC's transformation of the Race Street Pier into a landscaped public plaza has coincided with new development and construction plans nearby.

"You have to think in terms of future amenities," said local developer Carl Dranoff, who began renovating a printing plant near the Schuylkill into apartments because of plans for what is now Schuylkill River Park.

On the Delaware, the DRWC plans a trail that would replace a temporary asphalt lane bounded by a rusty chain-link fence through weedy lots.

The trail would be landscaped by RBA Group, which designed the Hudson River Valley Greenway Link in New York City. The project would rely on city and state funds and a grant by the William Penn Foundation, said Corcoran, who declined to disclose a budget for the work.

The recent transaction with Maryland-based K4 - which acquired the 18-acre site from Sheet Metal Workers Local 19 in March - closed on Aug. 24, the DRWC said. The nonprofit used an $850,000 state grant administered through the Natural Lands Trust to acquire the site from the developer.

The DRWC has secured another $850,000 state grant for the Blatstein-owned property, a 14-acre site where developers previously attempted to build a Foxwoods casino, Corcoran said.

Blatstein, who years ago developed much of the area's big-box retail, did not respond to repeated messages seeking comment.

K4 chief executive Jeffery Kozero said the trail would be a welcome addition to the mixed-use project that his company plans near the river, which would include residential units, shops, and restaurants.

The company will soon begin seeking permits for the project, aiming to break ground as soon as June, Kozero said.

"It's a tremendous aid because it promotes traffic to our project," he said of the trail. "We see it as a huge amenity."