Updated

Construction will soon begin on a new barrier to protect downtown Washington, D.C. and the National Mall from Potomac River flooding in the event of a massive storm.

Officials said Monday that the $9.6 million levee project will begin in late November or early December.

The U.S. Army Corps of Engineers concluded after Hurricane Katrina that Washington's flood-control system — built some 70 years ago — was inadequate for a major storm. The corps estimated a major storm could cause $200 million in damages to museums, memorials and federal office buildings.

The new system will add stone walls on both sides of 17th Street, as well as a removable section of posts and metal panels, to the earth barrier that parallels the Lincoln Memorial's reflecting pool.

The project is to be finished by next summer.