A Charleston development the size of a small city is hurtling toward realization with only a handful of people aware of what could be in store.

Cainhoy Plantation is a 9,000-acre tract of wooded land marbled with wetlands and overlooking the Wando River, Nowell Creek and the East Branch of the Cooper River. It is prized by conservationists and preservationists alike. Not only is it home to rare species of birds and to mature stands of the diminished longleaf pine tree, but it borders the historic St. Thomas and St. Denis Parish Church, and it still bears signs of the Road to Calais that traversed it in the early 19th century or before.

The Guggenheim family bought Cainhoy Plantation years ago as a place to hunt and entertain guests, who included Harry S. Truman.

On Nov. 20, the city of Charleston Planning Commission is scheduled to consider how that beautiful place could be transformed into a site with as many as 19,000 units of housing, plus light industrial, commercial and retail space.

But the master plan had not been finalized as of Friday, and it has therefore had precious little scrutiny by the public or the Planning Commission. The commission should defer consideration of the master plan and take it up only after the project’s planners hold a series of public charettes to solicit input from the broader community, which would feel a significant impact.

Even with limited information about the plan, knowledgeable people like Coastal Conservation League director Dana Beach have serious reservations about it. For example, they question the plan’s light industrial zoning for part of the property across narrow Cainhoy Road from the Francis Marion National Forest. It is near forest acreage which periodically requires controlled burning to protect its longleaf pines.

Critics contend further that the information provided so far is too little, too late to allow reasonable, helpful input.

Perhaps there are alternatives that the developer didn’t consider. The Guggenheims obviously valued the rural beauty of Cainhoy Plantation. Perhaps the present owners — members of the family and Guggenheim Capital — would opt to keep it undeveloped if they were given an economically viable way to do so.

The Daniel Island Company, which is handling the planning process for the owners, held one public meeting on Oct. 13 where neighbors expressed concerns about traffic and access to family graveyards. Matt Sloan of the Daniel Island Company said adjustments have been made in light of their recommendations. Just think how much helpful input the company could get if it held well-advertised, convenient meetings where people with different perspectives could speak.

Owners of nearby historic properties have experience that should be of interest. Several corporations with a presence in the area have granted easements on most of their property to protect it in perpetuity. Historians could describe Cainhoy Plantation’s significance to the rice culture and explain why the area around it was named a National Historic District.

Environmentalists could provide data about the native habitat and about how industrial uses too near the forest could be problematic.

Other developers could talk about how they planned for major projects like the one under consideration at Cainhoy and found alternate ways to build on the land without destroying its rural character. East Edisto is one example, and Poplar Grove is another.

At 9,000 acres, Cainhoy Plantation is similar in size to the Charleston peninsula from the Battery north to include Wagener Terrace. Of that, 5,000 acres are developable. The city approved nominal zoning for the property back in 1998.

The company is now ready to sell 100 acres for a Berkeley County high school, and to move forward on a major development. But no deal for the school property would justify rushing through the master planning process.

Now is the time to consider this mammoth project in context, and ensure that it is good for such a historic, rural area.