Eight years have passed since the Ford Motor Co. announced its intention to close, and eventually demolish, its giant assembly plant in St. Paul's Highland Park neighborhood. Another year may pass before it's ready to sell the now eerily barren site to a major developer. But the land's future is coming gradually into focus, thanks to patient and innovative planning from the city of St. Paul and its partners.

"This is the best site in the country for building a 21st-century community," Mayor Chris Coleman told an overflow crowd of neighbors on a snowy night last week. "We must seize this opportunity."

Coleman is right on both counts. The site is drop-dead spectacular — 130 acres along the Mississippi River, five miles from both downtowns, closer yet to the airport and the Mall of America, and a short hop from the Blue Line light-rail station at 46th Street. It's rare that such a large, centrally located, fully cleared parcel should come open for development, especially in the midst of an affluent neighborhood. It represents the Twin Cities' most significant urban design opportunity in decades.

As for Coleman's call to seize the opportunity, that's the harder part. But the city has begun to sketch more clearly a community that meets emerging real estate desires. Those include compact, tree-lined streets with nearby shopping, parks, bike lanes and transit stops, all aimed at minimizing the need to drive. "It's our job over the next year to set up the site for market success," said Jonathan Sage-Martinson, St. Paul's director of planning and economic development. Neighbors are getting anxious for something to happen, he added.

So, what will the Ford site look like in, say, 10 years? Start with the idea that it won't be a stand-alone community but an extension of the neighborhood. Conceptual drawings imagine shopping and dining along Ford Parkway with offices and other work sites running down the east side of the site. A large park dominates the south end. Housing takes up the bulk of the site, most of it lining a traditional grid of streets. A mixture of types is expected, including mid-rise buildings, townhouses and maybe a few detached dwellings on small lots. Market demand and land prices will dictate the mix, although the number of units is likely to exceed 1,000. Affordability and multigenerational appeal will be part of the plan.

A transit spine running north-south through the parcel is contemplated in a Riverview Corridor study underway at Ramsey County. One segment might connect the Ford site to the 46th Street station and downtown St. Paul's Union Depot. Zero-emission buses or streetcars are the most likely option. Indeed, the site's signature ambition is to leave the smallest possible carbon footprint. Net-zero energy techniques that emphasize wind and solar power are being studied along with other environment-friendly measures that could include reuse of Ford's old steam and wastewater plants and a network of underground utility tunnels.

Whether all of that is feasible may depend on how much pollution remains underground and how the developer decides to phase the project. An extensive zoning study by the city, expected to take 18 months and include community preferences, also will determine much about the site's eventual content and character.

Sage-Martinson, in his former role as a nonprofit mediator, was masterful in seeking the advice and support of neighbors along the Green Line, a far more contentious project. Smoother sailing is expected in Highland Park, where neighbors have been engaged since 2006 and are eager for new possibilities. Construction isn't expected to begin before 2018.

Losing the Ford plant was a blow to the region, but its replacement should add vitality and tax base to St. Paul and provide a model for other large infill projects on the horizon.