Credit: Photograph by Darrow Montgomery

From CityCenterDC to CityMarket at O, there are more than 50 cranes at work in D.C. right now. But in terms of acreage, these projects are nothing next to what’s coming. The city’s readying its biggest plots of undeveloped land for massive new projects­—­all involving ambitious master plans and enough land to make the usual stuff of development policy and politics seem small-bore.

The pièce de résistance—and there’s bound to be some résistance—is the sprawling campus of the St. Elizabeths Hospital (née Government Hospital for the Insane) between Anacostia and Congress Heights in Ward 8. The project is bifurcated: The redevelopment of the West Campus, intended to house the new Department of Homeland Security and Coast Guard headquarters, is underway and largely out of city planners’ control. But the East Campus, on the other side of Martin Luther King Avenue SE, is being readied for a complete makeover. The city is taking a piecemeal approach, starting with a temporary pavilion and a call for developers of residential and mixed-use buildings on four small parcels of land at the southern end of the site. If it all comes together, and the DHS folks cross Martin Luther King Avenue SE to visit the East Campus restaurants and shops, it could deliver a big jolt to retail-starved Ward 8.

Meanwhile, along North Capitol Street, plans are moving forward for development of the old McMillan Sand Filtration site, a perennial arena for vicious neighborhood battles over the pros and cons of developers’ proposals. The Vision McMillan Partners plan will turn the former water treatment plant, with its overgrown lawns and concrete filtration cells, into a mixed-use community of retail and housing, and a medical center that’s a key part of Mayor Vince Gray’s five-year economic development strategy. But the process could get held up by the city’s move to use part of the site to divert storm runoff that’s been flooding nearby Bloomingdale.

Farther north, the city’s planning to convert 67 acres of the former Walter Reed Army Medical Center on Georgia Avenue NW into a new development that’ll include housing and retail (a federal government-owned portion of the Walter Reed campus will become an embassy enclave). District officials are also looking for proposals for development of a vacant site of the same size, Reservation 13, near the Stadium-Armory Metro.

Don’t hold your breath for any of these projects to be finished. But don’t blink too long, either: If the city has its way, its biggest vacant sites will soon be unrecognizable.