Developers have quietly slated the long-neglected Anacostia area for close to 10 million square feet and $3 billion worth of housing, offices and retail overthe next four years — almost 20 times as much development as the underserved area has seen during the past six years.

“It’s like the frontier,” said Steve Moore, CEO of the Washington, D.C. Economic Partnership. “All of the pre-work — thinking, planning — is happening right now, and that’ll continue for another year. It’s hard to go now and see it, but that won’t last.”